UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended September 30, 2023

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 001-38537

AVROBIO, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	81-0710585
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
100 Technology Square Sixth Floor Cambridge, Massachusetts	02139
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (617) 914-8420

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, $0.0001 par value per share	AVRO	Nasdaq Global Select Market

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
		Emerging growth company	☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of November 2, 2023, the registrant had 44,573,911 shares of common stock, $0.0001 par value per share, outstanding.

Table of Contents

		Page
PART I.	FINANCIAL INFORMATION	1
Item 1.	Condensed Consolidated Financial Statements (Unaudited)	1
	Balance Sheets	1
	Statements of Operations and Comprehensive Income (Loss)	2
	Statements of Stockholders’ Equity	3
	Statements of Cash Flows	5
	Notes to Consolidated Financial Statements	6
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	21
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	29
Item 4.	Controls and Procedures	30
PART II.	OTHER INFORMATION	31
Item 1.	Legal Proceedings	31
Item 1A.	Risk Factors	31
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	76
Item 3.	Defaults Upon Senior Securities	76
Item 4.	Mine Safety Disclosures	76
Item 5.	Other Information	76
Item 6.	Exhibits	77
	Signatures	78

i

Summary of Risk Factors

Our business is subject to numerous risks and uncertainties that you should be aware of in evaluating our business. These risks include, but are not limited to, the following:

•We may not be successful in identifying and implementing any potential strategic alternatives, in a timely manner or at all, and any strategic transactions that we may consummate in the future could have negative consequences.

•Even if we successfully consummate any strategic transaction, or series of transactions, from our strategic assessment, including, but not limited to, an acquisition, merger, a business combination or divestiture, we may fail to realize all or any of the anticipated benefits of any such transaction, such benefits may take longer to realize than expected, we may encounter integration difficulties or we may be exposed to other operational and financial risks.

•If a strategic transaction is not consummated, our board of directors may decide to pursue a dissolution and liquidation. In such an event, the amount of cash available for distribution to our stockholders will depend significantly on the timing of such liquidation as well as the amount of cash that may need to be reserved for commitments and contingent liabilities.

•The value to stockholders in the event of a strategic transaction or dissolution may depend on the extent to which we will be able to successfully satisfy our existing contractual obligations to third parties and regulatory commitments on favorable terms, which may include the outcome of our negotiations to reduce or terminate such commitments.

•We have incurred net losses since inception. We expect to incur net losses for the foreseeable future and may never achieve or maintain profitability.

•If we decide to resume development of our product candidates, we will need additional funding, which may not be available on acceptable terms, or at all. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate our product development efforts or other operations.

•Business interruptions resulting from the coronavirus disease, or COVID-19 pandemic or similar public health crises have caused and may in the future cause a disruption of and adversely impact our business.

•Our hematopoietic stem cell, or HSC, lentiviral-based gene therapy product candidates are based on a novel technology, which makes it difficult to predict the time and cost of product candidate development and of subsequently obtaining regulatory approval, should we resume development of our product candidates.

•Our product candidates and the process for administering our product candidates may cause undesirable side effects or have other properties that, should we resume development of our product candidates, could delay or prevent their regulatory approval, limit their commercial potential or result in significant negative consequences following any potential marketing approval.

•Success in preclinical studies or early clinical trials may not be indicative of results obtained in later trials, should we resume development of our product candidates.

•Should we resume development of our product candidates, we may find it difficult to enroll patients in our clinical trials, which could delay or prevent us from proceeding with clinical trials of our product candidates.

•Should we resume development of our product candidates, we may encounter substantial delays in resuming our clinical trials or we may fail to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities.

•Should we resume development of our product candidates, even if we complete the necessary preclinical and clinical studies, we cannot predict whether or when we would be able to obtain regulatory approval to commercialize a product candidate, and any approval could be for a narrower indication than anticipated.

•Our commercially-scalable plato® platform has been used in only two of our clinical trials and clinical development has been halted.

•We face significant competition in our industry and, should we resume development of our product candidates, there can be no assurance that our product candidates, if approved, will achieve acceptance in the market over existing established therapies. In addition, our competitors may develop therapies that are more advanced or effective than ours, which may adversely affect our ability to successfully market or commercialize any of our product candidates, should we resume development of our product candidates.

•Gene therapies are novel, complex and difficult to manufacture. Should we resume development of our product candidates, we could experience production problems that result in delays in our development or commercialization programs or otherwise adversely affect our business.

ii

•Should we resume development of our product candidates, we expect to rely on third parties to conduct some or all aspects of our vector production, product manufacturing, protocol development, research and preclinical and clinical testing, and these third parties may not perform satisfactorily.

•We have historically relied, and, should we resume development of our product candidates, expect to continue to rely, on sole source suppliers for our automated, closed cell processing system; vector supply; plasmid supply; cell culture media supply; and drug product manufacturing. In addition, we are dependent on a limited number of suppliers for some of our other components and materials used in our product candidates.

•Should we resume development of our product candidates, third-party claims of intellectual property infringement may prevent or delay our development and commercialization efforts.

•Our rights to develop and commercialize our product candidates, should we resume development of our product candidates, are subject, in part, to the terms and conditions of licenses granted to us by others.

•If we experience material weaknesses or deficiencies in the future, or otherwise fail to establish and maintain effective internal controls, we may be unable to produce timely and accurate financial statements, and we may conclude that our internal control over financial reporting is not effective, which could adversely impact our investors’ confidence and our stock price.

•Our failure to meet Nasdaq Global Select Market’s, or Nasdaq, continued listing requirements could result in a delisting of our common stock.

The summary risk factors described above should be read together with the text of the full risk factors below, in the section entitled “Risk Factors” and the other information set forth in this Quarterly Report on Form 10-Q, including our consolidated financial statements and the related notes, as well as in other documents that we file with the Securities and Exchange Commission, or the SEC. The risks summarized above or described in full below are not the only risks that we face. Additional risks and uncertainties not precisely known to us, or that we currently deem to be immaterial may also materially adversely affect our business, financial condition, results of operations and future growth prospects.

iii

Note Regarding Forward-looking Statements

This Quarterly Report on Form 10-Q contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. These statements may be identified by such forward-looking terminology as “aims,” “anticipates,” “believes,” “continue,” “could,” “designed to,” “estimates,” “expects,” “forecasts,” “goal” “intends,” “may,” “plans,” “possible,” “potential,” “predicts,” “projects,” “seeks,” “strives,” “should,” “will,” and similar expressions or the negative of these terms. Our forward-looking statements are based on a series of expectations, assumptions, estimates and projections about our company, are not guarantees of future results or performance and involve substantial risks and uncertainty. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements. Our business and our forward-looking statements involve substantial known and unknown risks and uncertainties, including the risks and uncertainties inherent in our statements regarding:

•substantial uncertainties regarding our exploration of strategic alternatives to maximize stockholder value, including whether we are able to identify and implement any potential strategic alternatives, in a timely manner or at all, whether we realize all or any of the anticipated benefits of any such transaction and whether any such transactions would generate value for stockholders;

•the impact of the COVID-19 pandemic or any other public health crisis on our clinical trial programs, should we resume development of our product candidates, clinical supply and business generally;

•should we resume development of our product candidates, the timing, progress and results of preclinical studies and clinical trials for our programs and product candidates, including statements regarding the timing of initiation and completion of studies or trials and related preparatory work, the period during which the results of the trials will become available and our research and development programs;

•should we resume development of our product candidates, the existence or absence of side effects or other properties relating to our product candidates which could delay or prevent their regulatory approval, limit their commercial potential, or result in significant negative consequences following any potential marketing approval;

•the durability of effects from our product candidates, should we resume development of our product candidates;

•the timing, scope or likelihood of regulatory filings and approvals, should we resume development of our product candidates;

•should we resume development of our product candidates, the anticipated regulatory pathway for our product candidates and planned interactions with regulatory agencies;

•should we resume development of our product candidates, our ability to develop and advance product candidates into, and successfully complete, clinical studies;

•should we resume development of our product candidates, our expectations regarding the size of the patient populations for our product candidates, if approved for commercial use;

•the implementation of our business model and our strategic plans for our business, product candidates, should we resume development of our product candidates, technology and plato platform;

•should we resume development of our product candidates, our commercialization, marketing and manufacturing capabilities and strategy;

•should we resume development of our product candidates, the pricing and reimbursement of our product candidates, if approved;

•should we resume development of our product candidates, the scalability and commercial viability of our manufacturing methods and processes, including our move to a closed, automated system;

•should we resume development of our product candidates, the rate and degree of market acceptance and clinical utility of our product candidates, in particular, and gene therapy, in general;

•our ability to establish or maintain collaborations or strategic relationships or obtain additional funding;

•our competitive position;

•the scope of protection we and/or our licensors are able to establish and maintain for intellectual property rights covering our product candidates, should we resume development of our product candidates, as well as any statements as to whether we do or do not infringe, misappropriate or otherwise violate any third-party intellectual property rights;

iv

•our financial performance;

•our ability to retain the continued service of our key professionals and, should we resume development of our product candidates, to identify, hire and retain additional qualified professionals;

•should we resume development of our product candidates. developments and projections relating to our competitors and our industry, including other lentiviral or HSC gene therapy companies;

•our expectations related to the use of our cash reserves;

•our estimates regarding expenses, future revenue, capital requirements and needs for additional financing;

•our ability to avoid any findings of material weaknesses or significant deficiencies in the future;

•our ability to satisfy the continued listing requirements of the Nasdaq, including a minimum bid price, and to maintain our common stock listing on Nasdaq or any stock exchange;

•the impact of laws and regulations, including without limitation recently enacted tax reform legislation;

•our expectations regarding the time during which we are an emerging growth company under the Jumpstart Our Business Startups Act of 2012, or JOBS Act; and

•other risks and uncertainties, including those listed under the caption “Risk Factors.”

All of our forward-looking statements are as of the date of this Quarterly Report on Form 10-Q only. In each case, actual results may differ materially from such forward-looking information. We can give no assurance that such expectations or forward-looking statements will prove to be correct. An occurrence of or any material adverse change in one or more of the risk factors or risks and uncertainties referred to in this Quarterly Report on Form 10-Q or included in our other public disclosures or our other periodic reports or other documents or filings filed with or furnished to the Securities and Exchange Commission, or the SEC could materially and adversely affect our business, prospects, financial condition and results of operations. Except as required by law, we do not undertake or plan to update or revise any such forward-looking statements to reflect actual results, changes in plans, assumptions, estimates or projections or other circumstances affecting such forward-looking statements occurring after the date of this Quarterly Report on Form 10-Q, even if such results, changes or circumstances make it clear that any forward-looking information will not be realized. Any public statements or disclosures by us following this Quarterly Report on Form 10-Q that modify or impact any of the forward-looking statements contained in this Quarterly Report on Form 10-Q will be deemed to modify or supersede such statements in this Quarterly Report on Form 10-Q.

Note Regarding Trademarks

All brand names or trademarks appearing in this Quarterly Report are the property of their respective holders. Unless the context requires otherwise, references in this Quarterly Report to the “Company,” “we,” “us,” and “our” refer to AVROBIO, Inc.

v

PART I—FINANCIAL INFORMATION

Item 1. Financial Statements.

CONDENSED CONSOLIDATED BALANCE SHEETS

(unaudited)

(in thousands, except per share data)

	September 30, 2023			December 31, 2022
Assets
Current assets:
Cash and cash equivalents	$	105,842		$	92,563
Restricted cash		283			283
Prepaid expenses and other current assets		2,860			7,112
Held for sale assets		185			—
Total current assets		109,170			99,958
Operating lease assets		912			1,057
Property and equipment, net		—			2,894
Restricted cash, net of current portion		400			—
Other assets		40			40
Total assets	$	110,522		$	103,949
Liabilities and stockholders’ equity
Current liabilities:
Accounts payable	$	910		$	384
Accrued expenses and other current liabilities		5,002			11,732
Operating lease liabilities		1,647			999
Total current liabilities		7,559			13,115
Note payable, net of discount		—			15,276
Operating lease liabilities, net of current portion		105			188
Total liabilities		7,664			28,579
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock, $0.0001 par value; 150,000 shares authorized; 44,558 and 43,916 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively		4			4
Additional paid-in capital		571,344			564,798
Accumulated deficit		(468,490	)		(489,432	)
Total stockholders’ equity		102,858			75,370
Total liabilities and stockholders’ equity	$	110,522		$	103,949

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

1

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(unaudited)

(in thousands, except per share data)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Operating expenses:
Research and development	$	14,829		$	15,919		$	43,310		$	54,049
General and administrative		6,262			7,066			18,730			26,128
Total operating expenses		21,091			22,985			62,040			80,177
Gain on asset sale		—			—			83,736			—
Loss on impairment		(1,842	)		—			(1,842	)		—
(Loss) Income from operations		(22,933	)		(22,985	)		19,854			(80,177	)
Other (expense) income:
Interest income (expense), net		1,407			111			1,160			(544	)
Other expense, net		(51	)		(95	)		(72	)		(135	)
Total other income (expense), net		1,356			16			1,088			(679	)
Net income (loss) and comprehensive income (loss) attributable to common stockholders—basic and diluted	$	(21,577	)	$	(22,969	)	$	20,942		$	(80,856	)
Earnings per share:
Net income (loss) per share applicable to common stockholders—basic	$	(0.48	)	$	(0.52	)	$	0.47		$	(1.85	)
Net income (loss) per share applicable to common stockholders—diluted	$	(0.48	)	$	(0.52	)	$	0.47		$	(1.85	)
Shares used in computing earnings per share:
Weighted-average common shares outstanding—basic		44,528			43,773			44,235			43,722
Weighted-average common shares outstanding—diluted		44,528			43,773			44,426			43,722

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(unaudited)

(in thousands)

	Three Months Ended September 30, 2022
	Common Stock				Additional		Accumulated			Total Stockholders’
	Shares		Amount		Paid-in Capital		Deficit			Equity
Balance as of June 30, 2022		43,696	$	4	$	559,768	$	(441,429	)	$	118,343
Stock-based compensation expense		—		—		2,656		—			2,656
Issuance of common stock under the 2018 employee stock purchase plan		77		—		60		—			60
Net loss		—		—		—		(22,969	)		(22,969	)
Balance as of September 30, 2022		43,773	$	4	$	562,484	$	(464,398	)	$	98,090

	Nine Months Ended September 30, 2022
	Common Stock				Additional		Accumulated			Total Stockholders’
	Shares		Amount		Paid-in Capital		Deficit			Equity
Balance as of December 31, 2021		43,652	$	4	$	553,014	$	(383,542	)	$	169,476
Stock-based compensation expense		—		—		9,267		—			9,267
Issuance of common stock under the 2018 employee stock purchase plan		121		—		203		—			203
Net loss		—		—		—		(80,856	)		(80,856	)
Balance as of September 30, 2022		43,773	$	4	$	562,484	$	(464,398	)	$	98,090

	Three Months Ended September 30, 2023
	Common Stock				Additional		Accumulated			Total Stockholders’
	Shares		Amount		Paid-in Capital		Deficit			Equity
Balance as of June 30, 2023		44,308	$	4	$	568,946	$	(446,913	)	$	122,037
Vesting of restricted stock units		30		—		—		—			—
Exercise of stock options		107		—		106		—			106
Issuance of common stock under the 2018 employee stock purchase plan		113		—		73		—			73
Stock-based compensation expense		—		—		2,219		—			2,219
Net loss		—		—		—		(21,577	)		(21,577	)
Balance as of September 30, 2023		44,558	$	4	$	571,344	$	(468,490	)	$	102,858

3

	Nine Months Ended September 30, 2023
	Common Stock				Additional		Accumulated			Total Stockholders’
	Shares		Amount		Paid-in Capital		Deficit			Equity
Balance as of December 31, 2022		43,916	$	4	$	564,798	$	(489,432	)	$	75,370
Vesting of restricted stock units		284		—		—		—			—
Exercise of stock options		224		—		176		—			176
Issuance of common stock under the 2018 employee stock purchase plan		134		—		86		—			86
Stock-based compensation expense		—		—		6,284		—			6,284
Net income		—		—		—		20,942			20,942
Balance as of September 30, 2023		44,558	$	4	$	571,344	$	(468,490	)	$	102,858

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited)

(in thousands)

	Nine Months Ended September 30,
	2023			2022
Cash flows from operating activities:
Net income (loss)	$	20,942		$	(80,856	)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on asset sale		(83,736	)		—
Stock-based compensation expense		6,284			9,267
Depreciation and amortization expense		617			1,105
Non-cash asset impairment charges		1,842			—
Non-cash interest expense		1,074			260
Loss on disposal of property and equipment		—			59
Deferred rent expense		—			(231	)
Non-cash lease expense		1,597			—
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		4,252			(195	)
Other assets		—			33
Accounts payable		526			(1,672	)
Current and non-current operating lease liabilities		(1,827	)		—
Accrued expenses and other current liabilities		(6,730	)		(1,305	)
Net cash used in operating activities		(55,159	)		(73,535	)
Cash flows from investing activities:
Proceeds from asset sale, net		83,736			—
Purchases of property and equipment		(8	)		(267	)
Proceeds from the sale of property, plant, and equipment		1,198			—
Net cash provided by (used in) investing activities		84,926			(267	)
Cash flows from financing activities:
Repayment of note payable, including end of term charge		(16,350	)		—
Proceeds from exercise of stock options		176			—
Proceeds from issuance of ESPP shares		86			203
Net cash (used in) provided by financing activities		(16,088	)		203
Net increase (decrease) in cash, cash equivalents and restricted cash		13,679			(73,599	)
Cash, cash equivalents and restricted cash at beginning of period		92,846			190,059
Cash, cash equivalents and restricted cash at end of period	$	106,525		$	116,460
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	$	—		$	—
Interest paid		831			1,002
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets:
Cash and cash equivalents, end of period	$	105,842		$	115,968
Restricted cash		683			492
Cash, cash equivalents and restricted cash, end of period	$	106,525		$	116,460

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

5

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(in thousands, except share and per share data)

1. Nature of the Business

AVROBIO, Inc. (the “Company” or “AVROBIO”) is a gene therapy company which has been focused on developing potentially curative ex vivo lentiviral gene therapies to treat rare diseases following a single dose treatment regimen.

On July 12, 2023, following a comprehensive review of the Company’s business by its Board of Directors (the “Board”), the Company announced its intention to halt development of its programs and explore strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture. The decision was not related to any safety or medical issues or negative regulatory feedback related to the Company’s programs. See Note 13 for further discussion.

The Company is subject to risks and uncertainties including, should it resume development of its product candidates, risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Should the Company resume development of its product candidates, significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization, would be required. These efforts would require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, should the Company resume development of its product candidates, it is uncertain when, if ever, the Company would realize revenue from product sales.

In accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the consolidated financial statements are issued.

The Company has devoted substantially all of its efforts to research and development, business planning, acquiring operating assets, seeking protection for its technology and product candidates, and raising capital. Since inception, the Company has had recurring losses and has funded its operations through sales of preferred stock and common stock, a term loan facility and the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. As of September 30, 2023, the Company had an accumulated deficit of $468,490. The Company expects that its cash and cash equivalents of $105,842 as of September 30, 2023 will be sufficient to fund current planned operations and capital expenditure requirements for at least the next twelve months from the filing date of this Quarterly Report on Form 10-Q with the Securities and Exchange Commission (“SEC”). However, the future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed, should the Company resume development of its product candidates, could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurance that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all.

On May 19, 2023, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Novartis Pharma AG and Novartis Pharmaceuticals Corporation (collectively, “Novartis”), providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. The aggregate consideration to the Company consisted of a cash payment of $87,500 upon closing of the transaction. The Company completed the Asset Sale on June 9, 2023 and recognized $83,736 as a gain on asset sale, net of $3,764 transaction costs, in the condensed consolidated statement of operations and comprehensive income (loss) for the nine months ended September 30, 2023. See Note 3 for further discussion.

In July 2023, the Board approved a reduction in the Company’s workforce by approximately 50% across different areas and functions in the Company (the “July 2023 Workforce Reduction”). The July 2023 Workforce Reduction was substantially completed by the end of July 2023. The Company informed affected employees in the July 2023 Workforce Reduction on July 12, 2023. Since the date of the July 2023 Workforce Reduction, the Company’s remaining employees have primarily focused on activities relating to halting further development of the Company’s programs, the pursuit of strategic alternatives, and the provision of services under the previously disclosed Separation Services Agreement between the Company and Novartis in connection with the sale to Novartis of the Company’s cystinosis gene therapy program. The Company’s remaining workforce was further reduced by 11 employees in a workforce reduction implemented effective as of October 31, 2023 (the “October 2023 Workforce Reduction”). Affected employees

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

in the July 2023 Workforce Reduction and October 2023 Workforce Reduction were offered separation benefits, including severance payments. See Note 13 for further discussion.

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying condensed consolidated financial statements (the “unaudited condensed consolidated financial statements”) have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements as of and for the year ended December 31, 2022, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2023, and the results of its operations for the three and nine months ended September 30, 2023 and 2022, its statements of stockholders’ equity for the three and nine months ended September 30, 2023 and 2022 and its statement of cash flows for the nine months ended September 30, 2023 and 2022.

The results for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2022, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 23, 2023.

The unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the unaudited condensed consolidated financial statements. As of September 30, 2023, there have been no changes to the Company’s significant accounting policies as described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022.

Segment Information

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer (“CEO”). The Company and the CEO view the Company’s operations and manage its business as one operating segment. All material long-lived assets of the Company reside in the United States.

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AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Use of Estimates

The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires that the Company make estimates and judgments that may affect the reported amounts of assets, liabilities and expenses and the related disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates. Changes in estimates are reflected in reported results in the period in which they become known.

Significant estimates relied upon in preparing the unaudited condensed consolidated financial statements include the determination of the fair value of share-based awards issued and the estimation of accrued research and development expenses.

Stock-based Compensation

For stock-based awards issued to employees and members of the Company’s Board for their services on the Board, the Company measures the estimated fair value of the stock-based award on the date of grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The Company issues stock-based awards with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company has not issued any stock-based awards with performance- or market-based vesting conditions. The Company accounts for forfeitures as they occur.

Prior to the adoption of Accounting Standards Update (“ASU”) No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, the measurement date for non-employee awards was generally the date the services are completed, resulting in financial reporting period adjustments to stock-based compensation during the vesting terms for changes in the fair value of the awards. After adoption of ASU 2018-07, the measurement date for non-employee awards is the later of the adoption date of ASU 2018-07, or the date of grant, without change in the fair value of the award. For stock-based awards granted to nonemployees subject to graded vesting that only contain service conditions, the Company has elected to recognize stock-based compensation expense using the straight-line recognition method.

The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive income (loss) in the same manner in which the award recipient’s cash compensation costs are classified.

Emerging Growth Company Status

The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of its IPO or such earlier time that it is no longer an “emerging growth company.”

Subsequent Event Considerations

The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.

Recently Adopted Accounting Pronouncements

8

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, or ASU 2016-13. ASU 2016-13 requires that credit losses be reported as an allowance using an expected losses model, representing the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities with unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations.

In November 2019, the FASB issued ASU 2019-11, “Codification Improvements to Topic 326, Financial Instruments – Credit Losses,” or ASU 2019-11. ASU 2019-11 is an accounting pronouncement that amends ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendments update guidance on reporting credit losses for financial assets. These amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations.

3. License and Purchase Agreements

Agreement with The University of Manchester

On September 30, 2020, the Company entered into an agreement (“MPSII License Agreement”) with The University of Manchester, England (“UoM”), whereby UoM granted to the Company an exclusive worldwide license under certain patent and other intellectual property rights, subject to certain retained rights, to develop, commercialize and sell an ex vivo lentiviral gene therapy for use in the treatment of Hunter syndrome, or mucopolysaccharidosis type II (“MPSII”). As consideration for the MPSII License Agreement, the Company agreed to pay UoM an upfront, one-time fee of $8,000, which was recognized as research and development expense during the year ended December 31, 2020.

As part of the agreement, the Company was obligated to make milestone payments of up to an aggregate of $80,000 upon the achievement of specified development and regulatory milestones, to pay royalties, on a product-by-product and country-by-country basis, of a mid-single digit percentage based on net sales of products licensed under the agreement and to pay a low double digit percentage of any sublicense fees received by the Company. During the third quarter of 2022, a $2,000 milestone payment under the MPSII License Agreement became due following the date of regulatory approval of the CTA for the investigator-sponsored Phase 1/2 clinical trial sponsored by UoM.

Concurrently with the MPSII License Agreement, the Company entered into a collaborative research funding agreement with UoM (“CRFA”). Under the CRFA, the Company had agreed to fund the budgeted costs of an investigator-sponsored Phase 1/2 clinical trial to be sponsored by UoM in connection with the development activities under the MPSII License Agreement, which were expected to equal approximately £9,900 in the aggregate.

On September 8, 2023 the Company and UoM terminated the MPSII License Agreement and the CFRA, and in connection with such termination, the Company paid UoM £3,900. Following the termination of the MPSII License Agreement and the CFRA, the Company does not have any remaining financial obligations to UoM.

For the three months ended September 30, 2023, the Company did not incur costs related to the CRFA, excluding the payment made in connection with the termination. For the three months ended September 30, 2022, the Company incurred $590 related to the CRFA. For the nine months ended September 30, 2023 and 2022, the Company incurred $1,610 and $1,970 related to the CRFA, respectively, excluding the payment made in connection with the termination.

9

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Agreements with University Health Network (“UHN”)

Fabry License Agreement—

On January 27, 2016, the Company entered into an agreement with UHN, pursuant to which UHN granted the Company an option to enter into an exclusive license under the UHN intellectual property related to Fabry disease in accordance with the pre-negotiated licensing terms. On November 4, 2016, the Company exercised its option and entered into a license agreement with UHN, pursuant to which UHN granted the Company an exclusive worldwide license under certain intellectual property rights and a non-exclusive worldwide license under certain know-how, in each case subject to certain retained rights, to develop, commercialize and sell products for use in the treatment of Fabry disease. In addition, for three years following the execution of the agreement, UHN granted the Company an exclusive option to obtain a license under certain improvements to the licensed intellectual property rights as well as an option to negotiate a license under certain other improvements.

Under this agreement, the Company paid an option fee of CAD $20, an upfront license fee of CAD $75, plus the annual license maintenance fee for the first year. Thereafter, the Company is also required to pay UHN future annual license maintenance fees until the first sale of a licensed product in certain markets. The Company is also obligated to make future milestone payments in an aggregate amount of up to CAD $2,450 upon the achievement of specified milestones as well as royalties on a country-by-country basis of a low to mid-single-digit percentage of annual net sales of licensed products and a lower single-digit royalty percentage in certain circumstances. Additionally, the Company has agreed to pay a low double-digit royalty percentage of all sublicensing revenue.

The agreement requires the Company to meet certain performance milestones within specified timeframes. UHN may terminate the agreement if the Company fails to meet these performance milestones despite using commercially reasonable efforts and the Company is unable to reach agreement with UHN on revised timeframes. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis upon the latest to occur of the expiration or termination of the last valid claim under the licensed intellectual property rights in such country, the tenth anniversary of the first commercial sale of such licensed product in such country and the expiration of any applicable regulatory exclusivity in such country.

Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products. UHN can terminate the agreement if the Company fails to make any payments within a specified period after receiving written notice of such failure, or in the event that the Company fails to obtain or maintain insurance. Either the Company or UHN may terminate the license agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company can voluntarily terminate the agreement with prior notice to UHN.

On October 3, 2023 the Company provided a notice of termination to UHN with respect to the Fabry License Agreement, specifying an effective date of termination of January 4, 2024.

For the three months ended September 30, 2023, the Company recorded research and development expense related to this agreement with UHN of $25. For the three months ended September 30, 2022 the Company did not incur any research and development expense related to this agreement with UHN for reimbursable funded study trial costs. For the nine months ended September 30, 2023 and 2022, the Company recorded research and development expense related to this agreement with UHN of $59 and $106, respectively, which consists of reimbursable funded study trial costs. No milestone or maintenance fees were incurred related to this agreement in the three and nine months ended September 30, 2023 and 2022.

10

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Interleukin 12 License Agreement—

On January 27, 2016, the Company entered into an exclusive license agreement with UHN, pursuant to which UHN granted the Company a license to certain patent rights for the commercial development, manufacture, distribution and use of any products or processes resulting from development of those patent rights related to Interleukin 12. Upon execution of this agreement, the Company paid an upfront license fee of CAD $264. In addition, as part of the initial consideration for the license, the Company issued to UHN 1,161,665 shares of the Company’s common stock and agreed to pay UHN up to $2,000 upon the closing of an IPO if certain criteria are met. The fair value of the shares issued to UHN of $480 and the upfront fee was expensed upon the execution of the agreement. Upon the closing of the IPO in 2018, as the criteria were met, the Company paid UHN $2,000. The Company was also required to pay UHN future annual license maintenance fees of CAD $50 on each anniversary of the effective date of the license agreement prior to expiration or termination and potential future milestone payments of up to CAD $19,275 upon the achievement of specified clinical and regulatory milestones. The Company also agreed to pay UHN royalties of a low single-digit percentage of net sales of licensed products sold by the Company. If the Company granted any sublicense rights under the license agreement, the Company agreed to pay UHN a low double-digit royalty percentage of any sublicense income received by the Company. The agreement also required the Company to meet certain diligence requirements based upon specified milestones.

Effective as of August 24, 2023, the Company and UHN agreed to terminate the Interleukin 12 License Agreement. Following the termination of the agreement, the Company does not have any remaining financial obligations to UHN pursuant to the Interleukin 12 License Agreement.

For the three months ended September 30, 2023 the Company did not incur any costs related to this agreement with UHN. For the three months ended September 30, 2022, the Company recorded research and development expense related to this agreement with UHN of $39. For the nine months ended September 30, 2023 and 2022, the Company recorded research and development expense related to this agreement with UHN of $37 and $39, respectively. No milestone fees were incurred related to this agreement in the three and nine months ended September 30, 2023 and 2022.

Agreement with BioMarin Pharmaceutical Inc. (“BioMarin”)

On August 31, 2017, the Company entered into a license agreement with BioMarin, pursuant to which BioMarin granted the Company an exclusive worldwide license under certain intellectual property rights owned or controlled by BioMarin to develop, commercialize and sell products for use in the treatment of Pompe disease. The license agreement was amended in February 2018 and again in January 2020 to, among things, provide that BioMarin would supply the Company with certain technology materials. As consideration for this agreement, the Company paid an upfront license fee of $500 in cash and issued 233,765 shares of Series B Preferred Stock to BioMarin at the time of the Company’s Series B Preferred Stock financing in January 2018. The Company has a license agreement with BioMarin, pursuant to which BioMarin granted the Company an exclusive worldwide license under certain intellectual property rights owned or controlled by BioMarin to develop, commercialize and sell products for use in the treatment of Pompe disease. The Company is also obligated to make future milestone payments of up to $13,000 upon the achievement of certain specified milestones and agreed to pay BioMarin royalties of a low single-digit percentage of net sales of licensed products sold by the Company or its affiliates covered by patent rights in a relevant country.

The Company has recognized no expenses related to the license for the three and nine months ended September 30, 2023 and 2022.

Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. BioMarin and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon written notice to BioMarin. BioMarin has the right to terminate the agreement upon the Company’s bankruptcy or insolvency, or in the event of any challenge or opposition to the licensed patent rights or related actions brought by the Company or its affiliates or sublicensees, or if the Company, its affiliates or sublicensees knowingly assist a third-party in challenging or otherwise opposing the licensed patent rights, except as required under a court order or subpoena.

11

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Agreement with Papillon Therapeutics, Inc. (previously GenStem Therapeutics, Inc.)

On October 2, 2017, the Company entered into a license agreement with GenStem, pursuant to which GenStem granted the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights owned or controlled by GenStem to develop, commercialize and sell products for use in the treatment of cystinosis. Under this agreement, the Company paid an upfront license fee of $1,000 and is required to make payments upon completion of certain milestones up to an aggregate of $16,000. The Company also agreed to pay GenStem a tiered mid to high single-digit royalty percentage on annual net sales of licensed products as well as a low double-digit percentage of sublicense income received from certain third-party licensees. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis on the eleventh anniversary of the first commercial sale of such licensed product in such country or the expiration of the last valid claim under the licensed patent rights covering such licensed product in such country, whichever is later. Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. GenStem and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon the specified prior written notice to GenStem. In October 2021, the Company received noticed that the license agreement with GenStem had been assigned to Papillon Therapeutics, Inc. (“Papillon”). On June 9, 2023, in connection with the close of the Asset Purchase Agreement, discussed and defined above, the Company transferred this agreement to Novartis.

The Company has recognized no expenses related to this agreement for the three and nine months ended September 30, 2023 and 2022.

Agreement with Lund University Rights Holders

On November 17, 2016, the Company entered into a license agreement with affiliates of Lund University, along with certain other relevant rights holders that may be added from time to time, pursuant to which such rights holders granted to the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights to develop, commercialize and sell products in any and all uses relevant to Gaucher disease. As consideration for the license, the Company is required to make payments in connection with the achievement of certain milestones up to an aggregate of $550. The agreement expires on the latest of (i) the twentieth anniversary of the end of a certain research project the Company is funding pursuant to an agreement with Lund University, (ii) the expiration of the term of any patent filed on the licensed rights that covers a licensed product, (iii) the expiration of any applicable marketing exclusivity right and (iv) such time that neither the Company nor any sublicensees, partners or contractors are commercializing a licensed product. Either the Company or the rights holders acting together may terminate the license agreement if the other such party commits a material breach and fails to cure such breach within a certain period of time, or if the other party enters into liquidation, becomes insolvent, or enters into composition or statutory reorganization proceedings.

The Company has recognized no expenses related to this agreement for the three and nine months ended September 30, 2023 and 2022.

Sale of Cystinosis Program

On May 19, 2023, the Company entered into the Asset Purchase Agreement with Novartis, providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. In addition, pursuant to the Asset Purchase Agreement, the Company has granted an exclusive license to Novartis to use certain intellectual property of the Company, which consists of certain proprietary elements of the Company’s plato® gene therapy platform technology specifically within the field of cystinosis. The foregoing transactions contemplated by the Asset Purchase Agreement are referred to as the “Asset Sale.” The Company has also agreed not to assert claims against Novartis for violations of certain other Company intellectual property rights in connection with Novartis’s exercise of the exclusive license granted to it under the Asset Purchase Agreement, and for violations of the licensed intellectual property, except in connection with activities by Novartis in the fields of Gaucher disease, Pompe disease, Hunter syndrome and Fabry disease, or indemnification claims under the Asset Purchase Agreement. The aggregate consideration to the Company consisted of a cash payment of $87,500 upon closing of the transaction.

12

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

The Asset Purchase Agreement contains certain customary representations, warranties and covenants. The Asset Purchase Agreement also contains customary indemnification provisions pursuant to which the parties agree to indemnify each other for certain matters, including, among other things, breaches of certain representations, warranties and covenants in connection with the Asset Sale, subject to specified caps and limitations. The Company has also agreed to a covenant that would prohibit the Company from engaging in specified activities that would compete with the cystinosis business, for a period of 5 years, subject to certain limitations and exceptions. The Company completed the Asset Sale on June 9, 2023. For the three and nine months ended September 30, 2023 the Company recognized $83,736 as a gain on asset sale, net of $3,764 transaction costs, related to legal, accounting, and financial advisory services and transferred prepaid assets.

4. Fair Value Measurement

The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of September 30, 2023 and December 31, 2022:

	Fair Value Measurements as of September 30, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	104,541	$	—	$	—	$	104,541
	$	104,541	$	—	$	—	$	104,541

	Fair Value Measurements as of December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	91,095	$	—	$	—	$	91,095
	$	91,095	$	—	$	—	$	91,095

The fair value of cash equivalents was determined through quoted prices by third-party pricing services.

During the nine months ended September 30, 2023, there were no transfers between levels.

5. Supplemental Balance Sheet Information

Prepaid expenses and other current assets

Prepaid expenses and other current assets consisted of the following:

	September 30, 2023		December 31, 2022
Prepaid research and development expenses	$	828	$	4,509
Prepaid insurance		1,221		999
Other current assets		805		1,008
Prepaid compensation benefits		6		327
Tax incentive refund		—		269
Prepaid expenses and other current assets	$	2,860	$	7,112

13

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Property and equipment, net

Property and equipment, net consisted of the following:

	September 30, 2023			December 31, 2022
Laboratory and office equipment	$	5,973		$	5,967
Leasehold improvements		629			629
Computer equipment		104			102
		6,706			6,698
Less: Accumulated depreciation and amortization		(4,421	)		(3,804	)
Reclassified to held for sale		(2,285	)		—
Property and equipment, net	$	—		$	2,894
Reclassified to held for sale	$	2,285		$	—
Less: Loss on impairment		(902	)		—
Less: Sales		(1,198	)		—
Held for Sale	$	185		$	—

As of September 30, 2023, the Company had $185 of property and equipment classified as held for sale, and the Company's intention is to complete the sale of these assets within the fourth quarter of 2023. During the three and nine months ended September 30, 2023, $2,285 of assets were reclassified as held for sale and $1,198 were sold. For the three and nine months ended September 30, 2023, the Company recognized $902 as a loss on impairment on assets.

No depreciation or amortization expense was recognized for the three months ended September 30, 2023. Depreciation and amortization expense was $617 for the nine months ended September 30, 2023. Depreciation and amortization expense was $336 and $1,105, respectively, for the three and nine months ended September 30, 2022.

Restricted cash

As of September 30, 2023 and December 31, 2022, the Company had restricted cash as presented in the table below, which consists of cash used to secure letters of credit for the benefit of the landlord in connection with the Company’s lease agreements. The cash will be restricted until the termination or modification of the lease arrangement.

	September 30, 2023		December 31, 2022
Restricted cash	$	283	$	283
Restricted cash, net of current portion		400		—

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:

	September 30, 2023		December 31, 2022
Research and development expenses	$	1,479	$	6,122
Compensation and benefit costs		2,402		4,175
Consulting and professional fees		1,120		1,224
Other liabilities		1		211
Accrued expenses and other current liabilities	$	5,002	$	11,732

6. Leases

On August 31, 2018, the Company entered into a sublease agreement for office and lab space located in Cambridge Massachusetts, United States, which was set to expire in October 2020. On June 9, 2020, the Company amended the terms of the sublease, which was set to expire in April 2022. Effective January 1, 2022, the Company amended the terms of the sublease, to extend the term through April 2023. In July 2022, the Company moved its corporate headquarters to its subleased space in this location.

14

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

Effective January 24, 2023, the Company amended the terms of the sublease, which is now set to expire in April 2024. The annual lease payments are subject to a 5% increase each year. In accordance with the lease agreement, the Company is required to maintain a security deposit of $283, which was recorded in restricted cash as of September 30, 2023 and December 31, 2022. In July 2023, the Company ceased use of the lab space. This resulted in an impairment of the right of use asset of $940, recognized in the third quarter of 2023.

On June 1, 2020, the Company entered into a lease agreement for office space located in Toronto, Ontario, Canada, which is set to expire in June 2025. The annual lease payments are fixed for years 1 and 2, and then subject to a 6.67% increase for years 3 through 5. In accordance with the lease agreement, the Company is required to maintain a security deposit of CAD$27, which was recorded in other long-term assets as of September 30, 2023 and December 31, 2022. In October 2022, the Company entered into a sublease agreement to sublease this space. The term of the sublease agreement commenced on October 1, 2022 and expires on June 29, 2025.

The following table summarizes the effect of lease costs in the Company’s consolidated statement of operations and comprehensive income (loss):

	Three Months Ended September 30,
	2023
Operating lease costs	$	483
Sublease income		(23	)
Total lease costs	$	460

During the three months ended September 30, 2023 and 2022, the Company made cash payments for operating leases of $706 and $831, respectively. During the nine months ended September 30, 2023 and 2022, the Company made cash payments for operating leases of $2,088 and $2,493, respectively.

As of September 30, 2023, future minimum payments of operating lease liabilities are as follows (in thousands):

	September 30, 2023
2023	$	706
2024		1,033
2025		69
2026		—
2027		—
Thereafter		—
Total lease payments	$	1,808
Less: interest		(82	)
Plus: FX gain/loss		26
Present value of lease liabilities	$	1,752

As of September 30, 2023, the weighted average remaining lease term was 0.8 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 15.59%. As of September 30, 2022, the weighted average remaining lease term was 1.0 year and the weighted average incremental borrowing rate used to determine the operating lease liability was 10.51%.

15

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

7. Commitments and Contingencies

Legal Proceedings

The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the nine months ended September 30, 2023 and 2022 and to the best of the Company’s knowledge, no material legal proceedings are currently pending or threatened.

Other

The Company is also party to various agreements, principally relating to licensed technology, that require future payments relating to milestones not met at September 30, 2023 and December 31, 2022, or royalties on future sales. No milestone or royalty payments under these agreements are expected to be payable in the immediate future, except as disclosed in Note 3 “License Agreements.”

The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the agreements, the Company agrees to indemnify, hold harmless, and to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company’s business partners, in connection with any U.S. patent or any copyright or other intellectual property infringement claim by any third-party with respect to the Company’s products. Further, the Company indemnifies its directors and officers who are, or were, serving at the Company’s request in such capacities. The Company’s maximum exposure under these arrangements is unknown as of September 30, 2023. The Company does not anticipate recognizing any significant losses relating to these arrangements. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements.

8. Note Payable

On November 2, 2021 (the “Closing Date”), the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (“SVB”) pursuant to which a term loan in an aggregate principal amount of up to $50,000 (the “Term Loan Facility”) was available to the Company in three tranches, subject to certain terms and conditions. The first tranche of $15,000 was advanced to the Company on the Closing Date. Subject to the terms and conditions of the Loan Agreement, the first tranche allowed the Company to borrow an additional $15,000 through October 31, 2023. Upon satisfaction of certain milestones, the second and third tranches were available under the Term Loan Facility which allowed the Company to borrow an additional amount up to $10,000 in each tranche through October 31, 2023. Additionally, the Company could seek to borrow up to an additional $15,000 at the sole discretion of the lender through the term of the Loan Agreement. The Loan Agreement provided for an October 1, 2026 maturity date (the “Maturity Date”). The Company was required to pay an end of term fee (“End of Term Charge”) equal to 9.00% of the aggregate principal amount of the Term Loan advances upon repayment.

Advances under the Term Loan Facility bore interest at a rate equal to the greater of either (i) the Prime Rate (as reported in The Wall Street Journal) plus 4.85%, and (ii) 8.10%. The Company was obligated to make interest only payments through November 1, 2024. Following the interest only period, the Company was to repay the principal balance and interest of the advances in equal monthly installments through October 1, 2026.

The Company could prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge (the “Prepayment Premium”) equal to: (a) 1.50% of amounts so prepaid, if such prepayment occurred during the first year following the Closing Date; (b) 1.00% of the amount so prepaid, if such prepayment occurred during the second year following the Closing Date; and (c) 0.00% of the amount so prepaid, if such prepayment occurred after the second year following the Closing Date.

Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company was required to pay (in addition to any Prepayment Premium) an end of term charge of 9.0% of the aggregate funded amount under the Term Loan Facility.

The Term Loan Facility was secured by substantially all of the Company’s assets, other than the Company’s intellectual property. The Company agreed to not pledge or secure its intellectual property to others.

16

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

The End of Term Charge is recorded as a debt discount with an initial carrying balance of $1,350. During the year ended December 31, 2021 the Company recognized $103 of debt issuance costs related to legal expenses that has been included in the debt discount balance. The debt discount costs are being accreted to the principal amount of debt and being amortized from the date of issuance through the Maturity Date to interest expense using the effective-interest rate method. The effective interest rate of the outstanding debt under the Loan Agreement was approximately 16.29%.

On June 9, 2023, upon the closing of the Asset Sale, all outstanding amounts due and owed, including principal, interest, and other charges, under the Term Loan Facility, dated as of November 2, 2021, by and among the Company, Silicon Valley Bank, a division of First-Citizens Bank & Trust and the other parties thereto, were repaid in full and the Term Loan Facility was terminated. Upon repayment, the obligations of the Company under the Term Loan Facility were satisfied in full, the Term Loan Facility and all related loan documents were terminated and all liens and security interests granted thereunder were released and terminated (excluding certain indemnification obligations that expressly survive termination of the Term Loan Facility).

During the three months ended September 30, 2023 the Company did not recognize any interest expense related to the Loan Agreement, and during the three months ended September 30, 2022 the Company recognized $482 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. During the nine months ended September 30, 2023 and 2022, the Company recognized $1,917 and $1,280 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. Of the $1,917 recognized during the nine months ended September 30, 2023, $939 is related to the loss on the extinguishment of debt due to the write off of the debt discount balance.

9. Stockholders’ Equity

Common Stock

As of September 30, 2023 and December 31, 2022, the authorized capital stock of the Company included 150,000,000 shares of common stock, $0.0001 par value and 10,000,000 shares of undesignated preferred stock. As of September 30, 2023 and December 31, 2022, no undesignated preferred stock was outstanding.

As of September 30, 2023, no cash dividends have been declared or paid.

Common Stock Reserved for Future Issuance

As of September 30, 2023 and December 31, 2022, the Company has reserved the following shares of common stock for future issuance:

	September 30, 2023		December 31, 2022
Shares reserved for exercise of outstanding stock options		5,922,447		9,423,271
Shares reserved for vesting of restricted stock units		1,224,997		940,392
Shares reserved for issuance under the 2018 Stock Option and Grant Plan		7,287,262		5,005,295
Shares reserved for issuance under the 2018 Employee Stock Purchase Plan		1,332,587		1,467,026
Shares reserved for issuance under the 2019 Inducement Plan		1,137,800		786,656
Shares reserved for issuance under the 2020 Inducement Plan		1,700,000		1,637,000
Total shares of authorized common stock reserved for future issuance		18,605,093		19,259,640

10. Stock-based Compensation

Stock Option Valuation

The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis:

	Nine Months Ended September 30,
	2023			2022
Expected option life (years)		6.00			5.96
Risk-free interest rate		3.82	%		1.80	%
Expected volatility		83.36	%		80.22	%
Expected dividend yield		—	%		—	%

17

AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2023:

	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2022		9,423,271		$	7.26		8.14	$	22
Granted		123,501		$	1.09
Exercised		(223,273	)	$	0.79
Cancelled or forfeited		(3,401,052	)	$	7.15
Outstanding as of September 30, 2023		5,922,447		$	7.43		6.32	$	1,068
Exercisable as of September 30, 2023		3,606,590		$	10.16		4.82	$	217

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the underlying stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the estimated fair value of the Company’s common stock.

The aggregate intrinsic value of options exercised during the nine months ended September 30, 2023 was $85. No options were exercised during the nine months ended September 30, 2022.

The weighted-average grant-date fair value of the Company’s stock options granted during the nine months ended September 30, 2023 and 2022 was $0.79 and $1.23, respectively.

Restricted Stock Units

The following table summarizes the Company’s restricted common stock units for the nine months ended September 30, 2023:

	Number of Shares			Weighted- Average Grant Date Fair Value
Issued and unvested as of December 31, 2022		940,392		$	3.62
Granted		1,548,117		$	1.65
Vested		(283,835	)	$	4.98
Forfeited, cancelled or expired		(979,677	)	$	2.02
Issued and unvested as of September 30, 2023		1,224,997		$	2.10

The total fair value of restricted stock units vested during the nine months ended September 30, 2023 and 2022 was $1,367 and $7, respectively.

Stock-Based Compensation

Stock-based compensation expense was allocated as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	415	$	448	$	1,705	$	2,169
General and administrative		1,804		2,208		4,579		7,098
Total stock-based compensation expense	$	2,219	$	2,656	$	6,284	$	9,267

As of September 30, 2023, total unrecognized compensation cost related to the unvested stock-based awards was $6,282, which is expected to be recognized over a weighted-average period of 2.10 years.

11. Net Income (Loss) Per Share

The following table sets forth the computation of the Company’s basic and diluted net income (loss) per share for the three and nine months ended September 30, 2023 and 2022 (in thousands, except share and per share amounts):

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AVROBIO, INC.

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

(in thousands, except share and per share data)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023		2022
Numerator:
Net income (loss) attributable to common stockholders—basic and diluted	$	(21,577	)	$	(22,969	)	$	20,942	$	(80,856	)
Denominator:
Weighted-average common shares outstanding—basic		44,527,997			43,772,990			44,234,936		43,722,129
Weighted-average common shares outstanding—diluted		44,527,997			43,772,990			44,425,531		43,722,129
Net income (loss) per share applicable to common stockholders—basic	$	(0.48	)	$	(0.52	)	$	0.47	$	(1.85	)
Net income (loss) per share applicable to common stockholders—diluted	$	(0.48	)	$	(0.52	)	$	0.47	$	(1.85	)

The Company excluded the following potential common shares from the computation of diluted net income (loss) per share attributable to common stockholders for the three and nine months ended September 30, 2023 and 2022 because including them would have had an anti-dilutive effect:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Options to purchase common stock		4,827,316		8,083,363		7,683,446		8,083,363
Restricted stock units		276,008		870,536		1,414,256		870,536
Employee stock purchase plan		—		—		4,976		—

12. Related Party Transactions

UHN

For the three months ended September 30, 2023 and 2022, the Company recognized $25 and $82, respectively, of research and development expense related to the license agreements with UHN. For the nine months ended September 30, 2023 and 2022, the Company recognized $97 and $145, respectively, of research and development expense related to the license agreements with UHN. Refer to Note 3 “License Agreements” for additional information regarding the UHN license agreements.

Others

In the first quarter of 2023, the sublease for space that was previously provided by an entity affiliated with a member of the Company’s Board was assigned to Novartis. Therefore, for the three months ended September 30, 2023 the Company did not record expense related to a sublease to rent office and lab space provided by an entity affiliated with a member of the Company’s Board. For the three months ended September 30, 2022 the Company recorded $795 related to the sublease to rent office and lab space previously provided by an entity affiliated with a member of the Company’s Board. For the nine months ended September 30, 2023 and 2022, the Company recorded expenses of $754 and $2,381, respectively, related to the sublease to rent office and lab space previously provided by an entity affiliated with a member of the Company’s Board.

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13. Restructuring Activities

In July 2023, the Board approved a reduction in the Company’s workforce by approximately 50% across different areas and functions in the Company’s July 2023 Workforce Reduction. The July 2023 Workforce Reduction was substantially completed by the end of July 2023. The Company informed affected employees in the July 2023 Workforce Reduction on July 12, 2023. Since the date of the July 2023 Workforce Reduction, the Company’s remaining employees have primarily focused on activities relating to halting further development of the Company’s programs, the pursuit of strategic alternatives, and the provision of services under the previously disclosed Separation Services Agreement between the Company and Novartis in connection with the sale to Novartis of the Company’s cystinosis gene therapy program. Under the July 2023 Workforce Reduction, the Company recognized total restructuring expenses of $3,685 for the three and nine months ended September 30, 2023. These one-time employee termination benefits are related to affected employees, who were offered separation benefits, including severance payments. Approximately $2,782 of these payments were made during the three months ended September 30, 2023, $903 of these expenses were related to non-cash stock-based compensation expense, and there are no remaining accrued remaining payments at September 30, 2023.

	Employee Severance and Other Benefits
Restructuring expenses	$	3,685
Cash payments		(2,782	)
Non-cash expenses		(903	)
Liability included in accrued expenses and other current liabilities at September 30, 2023	$	—

14. Subsequent Events

The Company’s workforce was reduced by 11 employees in the October 2023 Workforce Reduction effective as of October 31, 2023. Affected employees in the October 2023 Workforce Reduction were offered separation benefits, including severance payments. The Company estimates that the severance and termination-related costs will total approximately $1.2 million in the aggregate and expects to primarily record these charges in the fourth quarter of 2023. The Company expects that payments of these costs will substantially be made through the end of the fourth quarter of 2023.

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and the related notes appearing elsewhere in this Quarterly Report on Form 10-Q and our audited consolidated financial statements and related notes for the year ended December 31, 2022 included in our Annual Report on Form 10-K for the year ended December 31, 2022. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks, uncertainties and assumptions. Factors that might cause future results to differ materially from those projected in the forward-looking statements include, but are not limited to, those set forth in our Annual Report on Form 10-K for the year ended December 31, 2022, as supplemented by our subsequent filings with the SEC.

Overview

We are a gene therapy company with a purpose to free people from a lifetime of genetic disease. Our company has been focused on developing potentially curative HSC gene therapies to treat patients with rare diseases following a single dose treatment regimen. The gene therapies we had been developing employ HSCs that are harvested from the patient and then modified with a lentiviral vector to insert the equivalent of a functional copy of the gene that is mutated in the target disease. We believe that our approach, which is designed to transform stem cells from patients into therapeutic products, has the potential to provide curative benefit for a range of diseases. Our development focus has been on a group of rare genetic diseases referred to as lysosomal disorders, some of which today are primarily managed with enzyme replacement therapies, or ERTs.

On July 12, 2023, following a comprehensive review of our business by our Board of Directors, we announced our intention to halt development of our programs and explore strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture.

Subsequently, in connection with ongoing cost reduction efforts related to our ongoing review of potential strategic alternatives, we have terminated all Company-sponsored treatment-related and Company-sponsored long-term follow-up clinical studies relating to our AVR-RD-02, or Gaucher disease type 1, program, and Company-sponsored long term follow-up studies relating to our AVR-RD-01, or Fabry disease, program (which we previously deprioritized). In addition, in September 2023, we terminated our agreements with the University of Manchester for the license and development of a gene therapy for MPSII, or Hunter syndrome, and discontinued our AVR-RD-05, or Hunter syndrome gene therapy program. Previously, in June 2023, we sold our cystinosis gene therapy program to Novartis Pharma AG and Novartis Pharmaceuticals Corporation, or collectively “Novartis”. As of the date of the filing of this Quarterly Report, we currently have a total of three gene therapy product candidates, none of which are currently in active clinical development, including AVR-RD-02 for the treatment of Gaucher disease type 1 and type 3, AVR-RD-03 for the treatment of Pompe disease and AVR-RD-01 for the treatment of Fabry disease.

Since our inception in 2015, we have devoted substantially all of our resources to organizing and staffing our company, business planning, raising capital, acquiring or discovering product candidates and securing related intellectual property rights, conducting discovery, research and development activities for our programs and planning for potential commercialization. To date, we have not generated any product revenue and have financed our operations primarily through the private placement of our securities and through public offerings of our common stock. Through September 30, 2023, we had received gross cash proceeds of $87.5 million from sales of our preferred stock; gross cash proceeds, before deducting underwriting discounts and commissions and expenses, of $428.1 million from sales of our common stock through our initial public offering and follow-on offerings; gross cash proceeds, before deducting commissions and expenses, of $23.5 million from sales of our common stock through our prior “at-the-market” facility, or our prior ATM facility; and gross proceeds, before deducting transaction costs, of $87.5 million from the sale of the Company’s cystinosis gene therapy program.

Additionally, we have incurred significant operating losses. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our current or future product candidates and programs. Our net income (loss) was $20.9 million and $(80.9) million for the nine months ended September 30, 2023 and 2022, respectively. As of September 30, 2023, we had an accumulated deficit of $468.5 million. Should we resume development of our product candidates, we would expect to continue to incur significant expenses for at least the next several years as we advance our product candidates from preclinical development and clinical trials and seek regulatory approval of our product candidates. Should we resume development of our product candidates, we would expect to expend significant resources to advance these candidates. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution.

Should we resume development of our product candidates, we would need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations with proceeds from outside sources, with a majority of such proceeds to be derived from

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sales of equity, including the net proceeds from our follow-on offerings and sales of common stock under our prior ATM facility. We may also pursue additional funding from outside sources, including our expansion of, or our entry into, new borrowing arrangements and our entry into potential future collaboration agreements for one or more of our programs. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed on favorable terms, or at all.

Because of the numerous risks and uncertainties associated with product development, we are unable to predict the timing or amount of increased expenses or when or if we will be able to achieve or maintain profitability, should we resume development of our product candidates. Even if we are able to generate product sales, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, we may be unable to continue our operations at planned levels and be forced to reduce or terminate our operations.

Components of Our Consolidated Results of Operations

Operating Expenses

Research and Development Expenses

Research and development expenses consist primarily of costs incurred in connection with the discovery and development of our product candidates. We expense research and development costs as incurred. These expenses consist of costs incurred in connection with the development of our product candidates, including:

•license maintenance fees and milestone fees incurred in connection with various license agreements;

•expenses incurred under agreements with contract research organizations, or CROs, contract manufacturing organizations, or CMOs, as well as investigative sites and consultants that conduct our clinical trials, preclinical studies and other scientific development services;

•manufacturing scale-up expenses and the cost of acquiring and manufacturing preclinical and clinical trial materials and commercial materials, including manufacturing validation batches;

•costs of purchasing lab supplies and non‑capital equipment used in our preclinical activities;

•employee-related expenses, including salaries, related benefits, travel and stock-based compensation expense for employees engaged in research and development functions;

•costs related to compliance with regulatory requirements; and

•allocated facilities costs, depreciation and other expenses, which include rent and utilities.

We recognize external development costs based on an evaluation of the progress to completion of specific tasks using information provided to us by our service providers.

Our direct research and development expenses are tracked on a program-by-program basis for our product candidates and consist primarily of external costs, such as fees paid to outside consultants, CROs, CMOs, and central laboratories in connection with our preclinical development, process development, manufacturing and clinical development activities. Our direct research and development expenses by program also include fees incurred under license agreements. We do not allocate employee costs or facility expenses, including depreciation or other indirect costs, to specific programs because these costs are deployed across multiple programs and, as such, are not separately classified. We use internal resources primarily to oversee the research and discovery as well as for managing our preclinical development, process development, manufacturing and clinical development activities. These employees work across multiple programs and, therefore, we do not track their costs by program.

The table below summarizes our research and development expenses related to our product candidates (in thousands):

	Three Months Ended September 30,						Nine Months Ended September 30,
	2023			2022			2023			2022
Fabry	$	1,424		$	1,568		$	2,829		$	5,464
Gaucher		2,382			2,085			9,796			4,998
Cystinosis		29			752			500			4,462
Hunter		4,879			2,634			6,597			4,577
Pompe		(55	)		(29	)		(58	)		569
Other research activities		11			40			189			65
Unallocated research and development expenses		6,159			8,869			23,457			33,914
Total research and development expenses	$	14,829		$	15,919		$	43,310		$	54,049

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Research and development activities will be central to our business model, should we resume development of our product candidates. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. As a result, should we resume development of our product candidates, we expect that our research and development expenses will increase substantially over the next several years, particularly as we increase personnel costs, including stock-based compensation, contractor costs and facilities costs, as we continue to advance the development of our product candidates. Should we resume development of our product candidates, we also expect to incur additional expenses related to milestone and royalty payments payable to third parties with whom we have entered into license agreements to acquire the rights to our product candidates. See “Risk Factors—Risks related to our business, financial position and need for additional capital—We have incurred net losses since inception. We expect to incur net losses for the foreseeable future and may never achieve or maintain profitability.”

The successful development and commercialization of our product candidates is highly uncertain. At this time, should we resume development of our product candidates, we cannot reasonably estimate or know the nature, timing and costs of the efforts that will be necessary to complete the preclinical and clinical development of any of our product candidates or when, if ever, material net cash inflows may commence from any of our product candidates. This uncertainty is due to the numerous risks and uncertainties associated with product development and commercialization, including the uncertainty of:

•the scope, progress, outcome and costs of our preclinical development activities, clinical trials and other research and development activities;

•establishing an appropriate safety profile with IND-enabling studies;

•successful patient enrollment in, and the design, initiation and completion of, clinical trials;

•the timing, receipt and terms of any marketing approvals from applicable regulatory authorities;

•establishing commercial manufacturing capabilities or making arrangements with third-party manufacturers;

•development and timely delivery of commercial-grade drug formulations that can be used in our clinical trials and for commercial launch;

•obtaining, maintaining, defending and enforcing patent claims and other intellectual property rights;

•significant and changing government regulation;

•launching commercial sales of our product candidates, if and when approved, whether alone or in collaboration with others;

•maintaining a continued acceptable safety profile of the product candidates following approval; and

•the risks disclosed in the section entitled “Risk Factors” of this Quarterly Report on Form 10-Q.

Should we resume development of our product candidates, we may never succeed in achieving regulatory approval for any of our product candidates. We may obtain unexpected results from our clinical trials. We may elect to discontinue, delay or modify clinical trials of some product candidates or focus on others. Any changes in the outcome of any of these variables with respect to the development of our product candidates in preclinical and clinical development could mean a significant change in the costs and timing associated with the development of these product candidates. For example, if the U.S. Food and Drug Administration, or FDA, or another regulatory authority were to delay our planned start of clinical trials or require us to conduct clinical trials or other testing beyond those that we currently expect, or if we experience significant delays in enrollment in any of our planned clinical trials for any reason, we could be required to expend significant additional financial resources and time on the completion of clinical development of that product candidate. Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries, related benefits, travel and stock-based compensation expense for personnel in executive, finance and administrative functions. General and administrative expenses also include professional fees for legal, consulting, accounting and audit services.

We anticipate that we may continue to incur increased accounting, audit, legal, regulatory, compliance, director and officer insurance costs as well as investor and public relations expenses associated with being a public company and our exploration of potential strategic alternatives. We anticipate the additional costs for these services could substantially increase our general and

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administrative expenses. Additionally, should we resume development of our product candidates, if and when we believe a regulatory approval of a product candidate appears likely, we anticipate an increase in payroll and expense as a result of our preparation for commercial operations, especially as it relates to the potential sales and marketing of our product candidates.

Other (Expense) Income, Net

Other (expense) income, net primarily consists of interest income earned on our cash and cash equivalents and changes in foreign currency, and interest expense related to our Term Loan Agreement, which was repaid in full and terminated on June 9, 2023.

Consolidated Results of Operations

Comparison of the three months ended September 30, 2023 and 2022

The following table summarizes our consolidated results of operations (in thousands):

	Three Months Ended September 30,
	2023			2022			Change
Operating expenses:
Research and development	$	14,829		$	15,919		$	(1,090	)
General and administrative		6,262			7,066			(804	)
Total operating expenses		21,091			22,985			(1,894	)
Loss on impairment		(1,842	)		—			(1,842	)
Loss from operations		(22,933	)		(22,985	)		52
Other (expense) income:
Interest income, net		1,407			111			1,296
Other expense		(51	)		(95	)		44
Total other expense, net		1,356			16			1,340
Net loss	$	(21,577	)	$	(22,969	)	$	1,392

Research and Development Expenses

Research and development expenses decreased by approximately $1.1 million to $14.8 million for the three months ended September 30, 2023, from $15.9 million for the three months ended September 30, 2022. This decrease was driven by a $2.5 million decrease in personnel-related and consulting costs, including non-cash stock-based compensation, a $2.1 million decrease in manufacturing costs, and a $0.3 million decrease in preclinical costs which was partially offset by a $3.8 million increase in development costs primarily related to the payment made in connection with the termination of the MPSII License Agreement.

General and Administrative Expenses

General and administrative expenses were $6.3 million for the three months ended September 30, 2023, compared to $7.1 million for the three months ended September 30, 2022. This decrease of $0.8 million was driven by a $1.4 million decrease in personnel-related and consulting costs, including non-cash stock-based compensation and a $0.6 million decrease in information technology-related costs which was partially offset by a $1.2 million increase in legal expenses.

Loss on Impairment

For the three months ended September 30, 2023 we recognized a $1.8 million loss on impairment. Of this amount, $0.9 million is related to the loss on impairment of property, plant, and equipment as a result of the reclassification of these assets to held for sale. In addition, $0.9 million is related to the loss on impairment of the right of use asset for the subleased lab space located in Cambridge, Massachusetts, which is no longer in use.

Other (Expense) Income, Net

Other (expense) income, net, was $1.4 million for the three months ended September 30, 2023, compared to $0.1 million for the three months ended September 30, 2022. This change is primarily due to the elimination of interest expense related to the Term Loan Agreement, which was paid off in the second quarter of 2023.

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Comparison of the nine months ended September 30, 2023 and 2022

The following table summarizes our consolidated results of operations (in thousands):

	Nine Months Ended September 30,
	2023			2022			Change
Operating expenses:
Research and development	$	43,310		$	54,049		$	(10,739	)
General and administrative		18,730			26,128			(7,398	)
Total operating expenses		62,040			80,177			(18,137	)
Gain on asset sale		83,736			—			83,736
Loss on impairment		(1,842	)		—			(1,842	)
Income (loss) from operations		19,854			(80,177	)		100,031
Other income (expense):
Interest income (expense), net		1,160			(544	)		1,704
Other expense		(72	)		(135	)		63
Total other income (expense), net		1,088			(679	)		1,767
Net income (loss)	$	20,942		$	(80,856	)	$	101,798

Research and Development Expenses

Research and development expenses decreased by approximately $10.7 million to $43.3 million for the nine months ended September 30, 2023, from $54.0 million for the nine months ended September 30, 2022. This decrease was driven by a $8.3 million decrease in personnel-related and consulting costs, including non-cash stock-based compensation, a $3.8 million decrease in manufacturing costs, and a $1.7 million decrease in preclinical costs which was partially offset by a $3.1 million increase in development costs primarily related to the payment made in connection with the termination of the MPSII License Agreement.

General and Administrative Expenses

General and administrative expenses were $18.7 million for the nine months ended September 30, 2023, compared to $26.1 million for the nine months ended September 30, 2022. This decrease of $7.4 million was driven by an $8.6 million decrease in personnel-related and consulting costs, including non-cash stock-based compensation and a $0.9 million decrease in information technology-related costs which was partially offset by a $2.0 million increase in legal expenses.

Gain on Asset Sale

For the nine months ended September 30, 2023 we recognized $83.7 million as a gain on asset sale, net of $3.8 million in transaction costs. We completed the Asset Sale on June 9, 2023.

Loss on Impairment

For the nine months ended September 30, 2023 we recognized a $1.8 million loss on impairment. Of this amount, $0.9 million is related to the loss on impairment of property, plant, and equipment as a result of the reclassification of these assets to held for sale. In addition, $0.9 million is related to the loss on impairment of the right of use asset for the subleased lab space located in Cambridge, Massachusetts, which is no longer in use.

Other Expense, Net

Other expense, net, was $1.1 million for the nine months ended September 30, 2023, compared to $(0.7) million for the nine months ended September 30, 2022. This change is primarily due to the elimination of interest expense related to the Term Loan Agreement, which was paid off in the second quarter of 2023.

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Liquidity and Capital Resources

Since our inception, we have not generated any revenue and have incurred significant operating losses and negative cash flows from our operations. We have funded our operations to date primarily with proceeds from the sale of preferred stock and our common stock through our IPO, and we have raised additional capital through subsequent follow-on offerings and our prior ATM facility. Through September 30, 2023, we had received gross cash proceeds of $87.5 million from sales of our preferred stock; gross cash proceeds, before deducting underwriting discounts and commissions and expenses, of $428.1 million from sales of our common stock through our initial public offering and follow-on offerings; gross cash proceeds, before deducting commissions and expenses, of $23.5 million from sales of our common stock under our prior ATM facility; $15.0 million drawn in term loans under our Term Loan Agreement, which was repaid in full and terminated on June 9, 2023; and gross proceeds, before deducting transaction costs, of $87.5 million from the sale of our cystinosis gene therapy program.

On July 1, 2019, we filed a shelf registration statement on Form S-3 with the SEC, or the July 2019 Shelf, which covers the offering, issuance and sale by us of up to an aggregate of $200.0 million of our common stock, preferred stock, debt securities, warrants and/or units. We simultaneously entered into a Sales Agreement with Cowen and Company, LLC, as sales agent, to provide for the offering, issuance and sale by us of up to $50.0 million of our common stock from time to time in ATM offerings under the July 2019 Shelf. The July 2019 Shelf was declared effective by the SEC on July 10, 2019.

On December 20, 2019, we filed a shelf registration statement on Form S-3 with the SEC, or the December 2019 Shelf, which covers the offering, issuance and sale by us of up to an aggregate of $250.0 million of our common stock, preferred stock, debt securities, warrants and/or units. The December 2019 Shelf was declared effective by the SEC on January 14, 2020.

In July 2019, we closed an underwritten public offering, or the July 2019 Follow-On Offering, under the July 2019 Shelf of 7,475,000 shares of our common stock at a public offering price of $18.50 per share, which included 975,000 shares of our common stock resulting from the full exercise of the underwriters’ option to purchase additional shares at the public offering price. The net proceeds to us from this offering, after deducting underwriting discounts and commissions and other offering expenses payable by us, were $129.5 million.

In February 2020, we closed an underwritten public offering, or the February 2020 Follow-On Offering, under the December 2019 Shelf of 4,350,000 shares of our common stock at a public offering price of $23.00 per share. The net proceeds to us from this offering, after deducting underwriting discounts and commissions and other offering expenses payable by us, were $93.6 million.

In June 2020, we sold an aggregate of 384,140 shares of common stock under the prior ATM facility for net proceeds, after deducting commissions and other offering expenses payable by us, of $8.1 million.

In November 2020, we closed an underwritten public offering, or the November 2020 Follow-On Offering, of 5,000,000 shares of our common stock at a public offering price of $15.00 per share. The net proceeds to us from the November 2020 Follow-On Offering, after deducting underwriting discounts and commissions and other offering expenses payable by us, were $70.2 million.

In May 2021, we sold an aggregate of 1,829,268 shares of common stock under the prior ATM facility for net proceeds, after deducting commissions and other offering expenses payable by us, of $14.5 million. As of September 30, 2023, approximately $26.5 million of common stock remained available for future issuance under the prior ATM facility.

On November 2, 2021, or the Closing Date, we entered into the Term Loan Agreement. The Term Loan Agreement provided for (i) on the Closing Date, $30.0 million aggregate principal amount of term loans available through October 31, 2023; (ii) an additional $20.0 million in term loan facilities available through October 31, 2023 upon the achievement of certain regulatory or clinical milestones prior to the time of draw, or the Milestone Funding; and (iii) an additional discretionary $15.0 million term loan facility available upon our request and approval by the Agent and the Lenders, or, collectively, the Term Loans. We drew $15.0 million in term loans on the Closing Date. On June 9, 2023, upon the closing of the Asset Sale, all outstanding amounts due and owed, including principal, interest, and other charges, under the Term Loan Agreement, dated as of November 2, 2021, by and among the Company, Silicon Valley Bank, a division of First-Citizens Bank & Trust and the other parties thereto, were repaid in full and the Term Loan Facility was terminated. Upon repayment, the obligations of the Company under the Term Loan Facility were satisfied in full, the Term Loan Facility and all related loan documents were terminated and all liens and security interests granted thereunder were released and terminated (excluding certain indemnification obligations that expressly survive termination of the Term Loan Facility).

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In July 2022, the July 2019 Shelf expired, and on November 8, 2022, we filed a shelf registration statement on Form S-3 with the SEC, or the November 2022 Shelf, which covered the offering, issuance and sale by us of up to an aggregate of $250.0 million of our common stock, preferred stock, debt securities, warrants and/or units. The December 2019 Shelf expired in December 2022, and the November 2022 Shelf carried forward unsold securities previously covered by the December 2019 Shelf, thus registering an aggregate total of $250.0 million of our common stock, preferred stock, debt securities, warrants and/or units. In connection with the November 2022 Shelf, we simultaneously entered into a new Sales Agreement with Cowen and Company, LLC, as sales agent, to provide for the offering, issuance and sale by us of up to $50.0 million of our common stock from time to time in “at-the-market” offerings under the November 2022 Shelf, or the 2022 ATM Facility. As of the date of this report, we have not made any sales under the 2022 ATM Facility. On November 3, 2023, we withdrew the November 2022 Shelf. We will not make sales under the 2022 ATM Facility until a new shelf registration statement on Form S-3 is filed and declared effective.

As of September 30, 2023, we had cash and cash equivalents of $105.8 million. Cash in excess of immediate requirements is invested primarily with a view to liquidity and capital preservation.

Cash Flows

The following table summarizes our cash flows for each of the periods presented (in thousands):

	Nine Months Ended September 30,
	2023			2022
Net cash used in operating activities	$	(55,159	)	$	(73,535	)
Net cash provided by (used in) investing activities		84,926			(267	)
Net cash (used in) provided by financing activities		(16,088	)		203
Net increase (decrease) in cash and cash equivalents	$	13,679		$	(73,599	)

Operating Activities

During the nine months ended September 30, 2023, operating activities used $55.2 million of cash, cash equivalents and restricted cash, resulting from our net income of $20.9 million offset by cash used by changes in our operating assets and liabilities of $3.8 million and non-cash charges of $72.3 million. The net change in our operating assets and liabilities was primarily due to a $6.7 million decrease in accrued expenses and other current liabilities and a $1.8 million decrease in current and non-current operating lease liabilities, partially offset by a $4.3 million decrease in prepaids and other current assets. The non-cash charges included $83.7 million of gain on asset sale, offset by $6.3 million of stock-based compensation expense, $1.8 million in non-cash asset impairment charges, $1.1 million in non-cash interest expense, $1.6 million in non-cash lease expense, and $0.6 million in depreciation and amortization expense.

During the nine months ended September 30, 2022, operating activities used $73.5 million of cash, cash equivalents and restricted cash, resulting from our net loss of $80.9 million and cash used by changes in our operating assets and liabilities of $3.1 million which was partially offset by non-cash charges of $10.5 million. The net change in our operating assets and liabilities was primarily due to a decrease in accounts payable of $1.7 million and a decrease in accrued expenses and other liabilities of $1.3 million. The non-cash charges primarily included $9.3 million of stock-based compensation expense and $1.1 million of depreciation and amortization expense.

Investing Activities

Net cash provided by investing activities was $84.9 million for the nine months ended September 30, 2023 compared to cash used by investing activities of ($0.3) million for the nine months ended September 30, 2022. The increase in cash provided by investing activities is related to the net proceeds received for the sale of the cystinosis program in the second quarter of 2023 for $83.7 million, and $1.2 million in proceeds from the sale of property, plant, and equipment.

Financing Activities

Net cash used by financing activities was $16.1 million for the nine months ended September 30, 2023 compared to cash provided by financing activities of $0.2 million for the nine months ended September 30, 2022. The change is related to the repayment of the Term Loan Agreement in the second quarter of 2023.

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Funding Requirements

Should we resume development of our product candidates, we may not be able to resume activities at the same costs as previously, and we expect our expenses would increase substantially, particularly as we advance the preclinical activities and clinical trials of our product candidates. Our expenses would also increase, should we resume development of our product candidates, as we:

•initiate additional clinical trials and preclinical studies for our product candidates;

•seek to identify and develop or in-license or acquire additional product candidates and technologies;

•seek to industrialize our ex vivo lentiviral gene therapy approach into a robust, scalable and, if approved, commercially viable process;

•seek marketing approvals for our product candidates that successfully complete clinical trials, if any;

•establish a sales, marketing and distribution infrastructure to commercialize any product candidates for which we may obtain marketing approval;

•hire and retain additional personnel, such as clinical, medical, manufacturing, quality, commercial and scientific personnel;

•expand our infrastructure, office space and facilities to accommodate our employee base, including adding equipment and physical infrastructure to support our research and development; and

•continue to incur additional public company-related costs.

Until such time, if ever, that we can generate product revenue sufficient to achieve profitability, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaboration agreements, government and other third-party funding, strategic alliances, licensing arrangements or marketing and distribution arrangements. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through government and other third-party funding, collaboration agreements, strategic alliances, licensing arrangements or marketing and distribution arrangements, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market products or product candidates that we would otherwise prefer to develop and market ourselves.

Contractual Obligations and Commitments

The disclosure of our contractual obligations and commitments is set forth under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Contractual Obligations and Commitments” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, filed with the SEC on March 23, 2023.

Critical Accounting Policies and Significant Judgments and Estimates

Our consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States. The preparation of our consolidated financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenue, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions. During the nine months ended September 30, 2023, there were no material changes to our critical accounting policies. Our critical accounting policies are described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations— Critical Accounting Policies and Significant Judgments and Estimates” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, which was filed with the SEC on March 23, 2023, and the notes to the consolidated financial statements included in Item 1, “Condensed Consolidated Unaudited Financial Statements,” of this Quarterly Report on Form 10-Q.

Emerging Growth Company Status

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and we may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. We may take advantage of these exemptions until we are no longer an emerging growth company. Section 107 of the JOBS Act provides that an emerging growth company can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. We have elected to use the extended

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transition period for complying with new or revised accounting standards and, as a result of this election, our financial statements may not be comparable to companies that comply with public company effective dates. We may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of our IPO or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company if we have more than $1.235 billion in annual revenue, we have more than $700.0 million in market value of our stock held by non-affiliates (and we have been a public company for at least 12 months and have filed one annual report on Form 10-K) or we issue more than $1.0 billion of non-convertible debt securities over a three-year period.

Recently Issued Accounting Pronouncements

A description of recently issued accounting pronouncements that may potentially impact our financial position and results of operations is disclosed in Note 2, “Summary of Significant Accounting Policies” to our consolidated financial statements appearing at the beginning of this Quarterly Report on Form 10-Q.

Item 3. Quantitative and Qualitative Disclosures about Market Risk.

Interest Rate Risk

As of September 30, 2023, we had cash and cash equivalents of $105.8 million, which consisted of primarily money market funds. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates, particularly because our cash equivalents are in held in short-term money market funds. Due to short-term duration of our investment portfolio and the low risk profile of our investments, an immediate 100 basis point change in interest rates would not have a material effect on the fair market value of our portfolio.

Foreign Currency Exchange Risk

We are exposed to foreign exchange rate risk. Our headquarters are located in the United States, where the majority of our general and administrative expenses and research and development costs are incurred in U.S. dollars. A portion of our research and development costs are incurred by our subsidiaries in Australia and Canada, whose functional currencies are the U.S. dollar but engage in transactions in Australian dollars and Canadian dollars, respectively. During the nine months ended September 30, 2023 and 2022, we recognized foreign currency transaction losses of $116 thousand and $70 thousand, respectively. These losses primarily related to unrealized and realized foreign currency gains and losses as a result of transactions entered into by our Australian and Canadian subsidiaries in currencies other than the U.S. dollar. These foreign currency transaction gains and losses were recorded in other expense, net in our consolidated statements of operations. We believe that a 10% change in the exchange rate between the U.S. dollar, Australian dollar, Great British Pound, and Canadian dollar would not have a material impact on our financial position or results of operations.

As we continue to grow our business, our results of operations and cash flows will be subject to fluctuations due to changes in foreign currency exchange rates, which could adversely impact our results of operations. To date, we have not entered into any foreign currency hedging contracts to mitigate our exposure to foreign currency exchange risk.

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Item 4. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our interim Chief Executive Officer and Chief Financial Officer (our principal executive officer and principal financial officer), evaluated the effectiveness of our disclosure controls and procedures as of September 30, 2023. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. While we continue to evaluate our disclosure controls and procedures, including new procedures and processes relating to our internal control over financial reporting, based on the evaluation of our disclosure controls and procedures as of September 30, 2023, our interim Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of September 30, 2023.

Changes in Internal Control over Financial Reporting

No change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) occurred during the three months ended September 30, 2023 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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PART II—OTHER INFORMATION

Item 1. Legal Proceedings.

From time to time, we may become subject to various legal proceedings and claims that arise in the ordinary course of our business activities. Although the results of litigation and claims cannot be predicted with certainty, as of September 30, 2023, we are not presently subject to any pending or threatened litigation that we believe, if determined adversely to us, would individually or in the aggregate be reasonably expected to have a material adverse effect on our business. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors.

Item 1A. Risk Factors.

Investing in our common stock involves a high degree of risk. You should carefully consider the following risks and uncertainties, together with all other information in this Quarterly Report on Form 10-Q, including our consolidated financial statements and related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as our other filings with the Securities and Exchange Commission, or the SEC, before investing in our common stock. Any of the risk factors we describe below could adversely affect our business, financial condition or results of operations. The market price of our common stock could decline if one or more of these risks or uncertainties were to occur, which may cause you to lose all or part of the money you paid to buy our common stock. Additional risks that are currently unknown to us or that we currently believe to be immaterial may also impair our business. Certain statements below are forward-looking statements. See “Forward-Looking Information” in this Quarterly Report on Form 10-Q.

Risks related to our strategic review process

We may not be successful in identifying and implementing any potential strategic alternatives in a timely manner or at all, and any strategic transactions that we may consummate in the future could have negative consequences.

In July 2023, we announced that we are undertaking a comprehensive exploration of strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture. We expect to devote substantial time and resources to exploring strategic alternatives that our board of directors believes will maximize stockholder value. Despite management devoting significant efforts to identify and evaluate potential strategic alternatives, there can be no assurance that this strategic review process will result in us pursuing any transaction or that we will be able to successfully consummate any particular strategic transaction on attractive terms, on a timely basis, or at all. For example, certain types of strategic transactions may require third party consents, such as stockholder approval, which could be difficult or costly to obtain. We have not set a timetable for completion of this strategic review process, and our board of directors has not approved a definitive course of action. Additionally, there can be no assurance that any particular course of action, business arrangement or transaction, or series of transactions, will be pursued, successfully consummated or lead to increased stockholder value or that we will make any cash distributions to our stockholders.

The process of continuing to evaluate our strategic alternatives may be costly, time-consuming and complex, and we may incur significant legal, accounting and advisory fees and other expenses, some of which may be incurred regardless of whether we successfully enter into a transaction. We may also incur additional unanticipated expenses in connection with this process. Any such expenses will decrease the remaining cash available for use in our business. Our ability to pursue or consummate strategic transactions also depends upon our ability to retain certain of our employees, the loss of whose services may adversely impact the ability to identify, negotiate and consummate such transaction. If we are unable to successfully retain certain of our key remaining personnel, we are at risk of a disruption to our exploration and consummation of one or more strategic transactions.

In addition, potential counterparties in a strategic transaction involving the Company may place minimal or no value on our assets and our public listing. Further, should we resume the development of our product candidates, the development and any potential commercialization of our product candidates will require substantial additional cash to fund the costs associated with conducting the necessary preclinical and clinical testing and obtaining regulatory approval. Consequently, any potential counterparty in a strategic transaction involving the Company may choose not to spend additional resources to resume or continue development of our product candidates and may attribute little or no value, in such a transaction, to our product candidates.

In addition, any strategic transactions that we may pursue could have a variety of negative consequences, and we may enter into a transaction that yields unexpected results that adversely affects our business and decreases the remaining cash available for use in our business. Any potential transaction would be dependent on a number of factors that may be beyond our control, including, among other things, market conditions, industry trends, the interest of third parties in a potential transaction with us, obtaining stockholder approval and the availability of financing to third parties in a potential transaction with us on reasonable terms. There can be no assurance that any particular course of action, business arrangement or transaction, or series of transactions, will be pursued, successfully consummated, lead to increased stockholder value, or achieve the anticipated results.

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If we are not successful in setting forth a new strategic path for the Company, or if our plans are not executed in a timely fashion, this may cause reputational harm with our stockholders and the value of our securities may be adversely impacted. In addition, speculation regarding any developments related to the review of strategic alternatives and perceived uncertainties related to the future of the Company could cause our stock price to fluctuate significantly.

Even if we successfully consummate any strategic transaction, or series of transactions, from our strategic assessment, including, but not limited to, an acquisition, merger, a business combination or divestiture, we may fail to realize all or any of the anticipated benefits of any such transaction, such benefits may take longer to realize than expected, we may encounter integration difficulties or we may be exposed to other operational and financial risks.

The market capitalization of our company is below the value of our current cash and cash equivalents. Potential counterparties in a strategic transaction involving our company may place minimal or no value on our assets, including the programs in our pipeline for which we halted further development in July 2023. Further, the development and any potential commercialization of our product candidates, should we determine to resume development, will require substantial additional cash to fund the costs associated with conducting the necessary preclinical and clinical testing and obtaining regulatory approval, as the case may be. Consequently, any potential counterparty in a strategic transaction involving our company may choose not to spend additional resources to resume and continue development of our product candidates and may attribute little or no value, in such a transaction, to those product candidates. To the extent that the development of any of our product candidates is resumed following a strategic transaction, including by a potential counterparty, third-party licensee or other collaborator, such development will be subject to the risks related to product development discussed elsewhere in these Risk Factors.

Our ability to realize the anticipated benefits of any potential strategic transaction will depend on a number of factors, including our ability to integrate with any future business partner, our ability to obtain value for portions of our business, if divested, and our ability to generate future stockholder value. The process may be disruptive to our business and the expected benefits may not be achieved within the anticipated time frame, or at all. The failure to meet the challenges involved and to realize the anticipated benefits of any potential transaction could adversely affect our business and financial condition. The negotiation and consummation of any potential strategic transaction will require significant time on the part of our management, and the diversion of management’s attention may disrupt our business.

The negotiation and consummation of any such transaction may also require more time or greater cash resources than we anticipate and expose us to other operational and financial risks, including, but not limited to, increased near-term and long-term expenditures, exposure to unknown liabilities, higher than expected acquisition or integration costs, incurrence of substantial debt or dilutive issuances of equity securities to fund future operations, including financings in connection with a strategic transaction, write-downs of assets or goodwill or incurrence of non-recurring, impairment or other charges, increased amortization expenses, difficulty and cost in combining the operations and personnel of any acquired or acquiring business with our operations and personnel, impairment of relationships with key suppliers or customers of any acquired or acquiring business due to changes in management and ownership, inability to retain key employees of the Company or any acquired or acquiring business and possibility of future litigation. Any of the foregoing risks could have a material adverse effect on our business, financial condition and prospects.

If a strategic transaction is not consummated, our board of directors may decide to pursue a dissolution and liquidation. In such an event, the amount of cash available for distribution to our stockholders will depend significantly on the timing of such liquidation as well as the amount of cash that may need to be reserved for commitments and contingent liabilities.

There can be no assurance that a strategic transaction will be completed. If a strategic transaction is not completed, our board of directors may decide to pursue a dissolution and liquidation. In such an event, the amount of cash available for distribution to our stockholders will depend heavily on the timing of such decision and, with the passage of time, the amount of cash available for distribution will be reduced as we continue to fund our operations. In addition, if our board of directors were to approve and recommend, and our stockholders were to approve, a dissolution and liquidation, we would be required under Delaware corporate law to pay our outstanding obligations, as well as to make reasonable provision for contingent and unknown obligations, prior to making any distributions in liquidation to our stockholders. As a result of this requirement, a portion of our assets may need to be reserved pending the resolution of such obligations and the timing of any such resolution is uncertain. In addition, we may be subject to litigation or other claims related to a dissolution and liquidation. If a dissolution and liquidation were pursued, our board of directors, in consultation with our advisors, would need to evaluate these matters and make a determination about a reasonable amount to reserve. Accordingly, holders of our common stock could lose all or a significant portion of their investment in the event of a liquidation, dissolution or winding up.

The value to stockholders in the event of a strategic transaction or dissolution may depend on the extent to which we will be able to successfully satisfy our existing contractual obligations to third parties and regulatory commitments on favorable terms, which may include the outcome of our negotiations to reduce or terminate such commitments.

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We are currently subject to certain contractual and regulatory obligations and commitments. In connection with our comprehensive exploration of strategic alternatives, we may seek to negotiate with third parties in order to reduce or eliminate such obligations and commitments. Our ability to successfully negotiate such obligations or commitments on favorable terms, or at all, or our ability to satisfy any such obligations may impact our ability to pursue a strategic transaction on terms favorable to us, the resulting value to stockholders in a strategic transaction or the cash available for distribution to our stockholders in the event of our dissolution. We may also incur substantial costs in connection with or as a result of such negotiations or termination of any of our commitments. There can be no assurance that we will be successful in negotiating to reduce or eliminate any of our existing contractual or regulatory obligations and commitments, or that we will be able to satisfy any such obligations on a timetable that will allow us to maximize potential value to our stockholders.

We may become involved in litigation, including securities class action litigation, that could divert our management’s attention and harm the Company’s business, and insurance coverage may not be sufficient to cover all costs and damages.

In the past, litigation, including securities class action litigation, has often followed certain significant business transactions, such as the sale of a company or announcement of any other strategic transaction, or the announcement of negative events. These events may also result in investigations by the SEC. We may be exposed to such litigation even if no wrongdoing occurred. Litigation is usually expensive and diverts management’s attention and resources, which could adversely affect our business and cash resources and our ability to consummate a potential strategic transaction or the ultimate value our stockholders receive in any such transaction.

Risks related to our business, financial position and need for additional capital

We have incurred net losses since inception. We expect to incur net losses for the foreseeable future and may never achieve or maintain profitability.

Since inception, we have incurred annual net losses. We incurred net losses of $105.9 million and $119.1 million for the years ended December 31, 2022 and 2021, respectively, and net income of $20.9 million for the nine months ended September 30, 2023. We historically financed our operations primarily through private placements of our preferred stock and, more recently, our initial public offering and follow-on public offerings of our common stock, as well as sales of our common stock under our prior ATM facility. Although we have established the 2022 ATM Facility, as of the date of this report, we have not made any sales under the 2022 ATM Facility, and we will not make sales under the 2022 ATM Facility unless and until a new shelf registration statement on Form S-3 is filed and declared effective. In addition, on November 2, 2021 we entered into the Loan and Security Agreement, or the Term Loan Agreement, by and among the Company, the lenders party thereto from time to time and Silicon Valley Bank or its successor, Silicon Valley Bank, a division of First-Citizens Bank & Trust company, which we refer to as SVB. In May 2023, we announced that we had entered into an Asset Purchase Agreement with Novartis providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program for an aggregate cash payment of $87.5 million upon closing of the transaction. In June 2023, we announced the closing of this transaction, as well as the pay-off of all outstanding amounts due and owed, including principal, interest and other charges, under the Term Loan Agreement and the termination thereof.

We have devoted substantially all of our efforts to research and development, including clinical and preclinical development of our product candidates, as well as assembling our team. In July 2023, we announced the decision to halt further development of the Company’s programs and to conduct a comprehensive exploration of strategic alternatives, and as such, our research and development expenses have decreased. Should we resume development of our product candidates, we expect that research and development costs would increase significantly, that it will be several years, if ever, before we commercialize any product candidates, and that we would continue to incur significant expenses and increasing operating losses for the foreseeable future thereafter. We also anticipate that our expenses would increase substantially should we resume development of our product candidates and if, and as, we:

•resume clinical trial enrollment activities, particularly if and as we commence or resume clinical-stage activities for our product candidates;

•initiate additional clinical trials and preclinical studies for our product candidates, if any;

•experience delays or interruptions in preclinical studies, clinical trials, or our supply chain due to the COVID-19 pandemic;

•seek to identify and develop or in-license additional product candidates;

•seek marketing approvals for our product candidates that successfully complete clinical trials, if any;

•establish a sales, marketing and distribution infrastructure to commercialize any product candidates for which we may obtain marketing approval;

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•resume implementation of our plato platform as we seek to industrialize our HSC gene therapy approach into a robust, scalable and, if approved, commercially viable process;

•hire and retain additional personnel, such as clinical, quality control, regulatory and scientific personnel;

•expand our office space, infrastructure and facilities as needed to accommodate our employee base, including adding equipment and physical infrastructure to support our research and development; and

•continue to incur additional public company-related costs.

We expect to continue to incur costs and expenditures in connection with the process of evaluating our strategic alternatives. Should we resume development of our product candidates, to become and remain profitable, we must successfully develop and eventually commercialize product candidates with significant market potential and acceptance. This will require us to be successful in a range of challenging activities, and our expenses will increase substantially as we seek to resume, initiate, conduct and complete preclinical and clinical trials of our product candidates, and manufacture, market and sell these or any future product candidates for which we may obtain marketing approval, if any, and satisfy any post-marketing requirements. Should we resume development of our product candidates, we may never succeed in any or all of these activities and, even if we do, we may never generate revenues that are significant or large enough to achieve profitability. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our Company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our Company also could cause you to lose all or part of your investment.

Our audited financial statements for the year ended December 31, 2022 and the accompanying report of our independent registered public accounting firm included a discussion of the circumstances giving rise to substantial doubt about our ability to continue as a going concern. Substantial doubt about our ability to continue as a going concern, the Company’s inability to raise adequate capital as and when needed and the Company’s ability to identify and successfully consummate any strategic alternative may create negative reactions to the price of our common stock and could have a negative impact on our financial condition and ability to pursue our business strategies. There can be no assurance that our current operating plan will be achieved or that additional funding will be available at levels sufficient to fund our operations or on terms acceptable to us, or at all. In July 2023, we announced that we are undertaking a comprehensive exploration of strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture. Certain types of strategic alternatives, such as a reverse merger, may require the continuing business to raise capital in connection with such transaction, which financing may not be completed in a timely manner, on favorable terms or at all. There can be no assurance that any particular course of action, business arrangement or transaction, or series of transactions, will be pursued, successfully consummated or lead to increased stockholder value. Further, if we do not obtain additional funding and/or if a strategic transaction is not completed and we are unable to continue as a going concern, we may have to liquidate our assets and the values we receive for our assets in liquidation or dissolution could be significantly lower than the values reflected in our consolidated financial statements.

We have never generated revenue from product sales and do not expect to do so for the next several years, if ever.

Our ability to generate revenue from product sales and achieve profitability depends on our ability, alone or with collaborative partners, to successfully resume and complete the development of, and obtain the regulatory approvals necessary to commercialize, our product candidates. We do not anticipate generating revenues from product sales for the next several years, if ever. Should we resume development of our product candidates, our ability to generate future revenues from product sales depends heavily on our, or our collaborators’, success in:

•re-initiating and completing research and preclinical and clinical development of our product candidates;

•seeking and obtaining regulatory and marketing approvals for product candidates for which we complete clinical trials;

•launching and commercializing product candidates for which we obtain regulatory and marketing approval by establishing a sales force, marketing and distribution infrastructure or, alternatively, collaborating with a commercialization partner;

•qualifying for adequate coverage and reimbursement by government and third-party payors for our product candidates;

•establishing and maintaining supply and manufacturing processes and relationships with third parties that can provide adequate, in both amount and quality, products and services to support clinical development and the commercial market demand for our product candidates, if approved;

•obtaining market acceptance of our product candidates, if approved, as a viable treatment option;

•addressing any competing technological and market developments;

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•negotiating favorable terms in any collaboration, licensing or other arrangements into which we may enter and performing our obligations under such arrangements; and

•attracting, hiring and retaining qualified personnel.

Should we resume development of our product candidates, and one or more of the product candidates that we develop is approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product candidate. Our expenses could increase beyond expectations if we are required by the FDA or other foreign regulatory authorities to perform clinical and other studies in addition to those that we currently anticipate would be required. Even if we are able to generate revenues from the sale of any approved products, we may not become profitable and may need to obtain additional funding to continue operations.

If we decide to resume development of our product candidates, we will need additional funding, which may not be available on acceptable terms, or at all. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate our product development efforts or other operations.

Should we resume development of our product candidates, particularly if we resume the research and development of, initiate further clinical trials of and seek marketing approval for, our product candidates and continue to enhance and optimize our vector technology and manufacturing processes, we expect our expenses would increase in connection with such activities. In July 2023, we announced we were halting further development of our programs. Following such announcement, in September 2023 we terminated our agreements with the University of Manchester for the license and development of a gene therapy for MPSII, or Hunter syndrome, and discontinued our AVR-RD-05, or Hunter syndrome gene therapy program. Previously, in June 2023, we sold our cystinosis gene therapy program to Novartis. As of the date of the filing of this Quarterly Report, we have a total of three gene therapy product candidates, for Gaucher, Pompe and Fabry diseases, none of which is currently in clinical development. Resumption of the development of these product candidates, if that were to occur, would require us to expend significant resources to advance these candidates. In addition, should we resume development of our product candidates and thereafter obtain marketing approval for any of our product candidates, we would expect to incur significant expenses related to product sales, medical affairs, marketing, manufacturing and distribution. Though we have halted further development of the Company’s programs to conduct a comprehensive exploration of strategic alternatives and have conducted reductions in force, we may incur significant costs in connection with a comprehensive review of strategic alternatives, and we have incurred, and may in the future incur, significant costs related to this continued evaluation. We may also incur additional unanticipated expenses in connection with this process. Furthermore, we expect to continue to incur additional costs associated with operating as a public company. Accordingly, should we resume development of our product candidates, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on reasonable terms, and/or if a strategic transaction is not completed, we may have to liquidate our assets. Our future capital requirements will depend on many factors, including:

•our exploration of strategic alternatives to maximize stockholder value, including whether we are able to identify and implement any potential strategic alternatives, in a timely manner or at all, whether we realize all or any of the anticipated benefits of any such transaction and whether any such transactions would generate value for our stockholders;

•should we resume development of our product candidates, the scope, progress, results and costs of drug discovery, laboratory testing, preclinical development and clinical trials for our product candidates, including the extent of any impacts from the COVID-19 pandemic or similar public health crisis on these activities;

•should we resume development of our product candidates, the costs, timing and outcome of regulatory review of our product candidates;

•the costs of future activities, including, should we resume development of our product candidates, product sales, medical affairs, marketing, manufacturing and distribution, for any of our product candidates for which we receive marketing approval;

•should we resume development of our product candidates, the costs associated with our manufacturing process development and evaluation of third-party manufacturers;

•revenue, if any, should we resume development of our product candidates, received from commercial sale of our products, should any of our product candidates receive marketing approval;

•the amounts, if any, raised from potential financings and capital raising activities should we resume development of our product candidates;

•the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims;

•the costs of defending against and resolving adverse litigation, if any;

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•the terms of our current and any future license agreements and collaborations; and

•the extent to which we acquire or in-license other product candidates, technologies and intellectual property

Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and should we resume development of our product candidates, we may never generate the necessary data or results required to obtain marketing approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our product revenues, if any, will be derived from or based on sales of products that may not be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all.

Entry into an acquisition, merger, business combination, or other strategic transaction, or raising additional capital may cause dilution to our existing stockholders, restrict our operations or cause us to relinquish valuable rights.

In July 2023, we announced our intention to explore strategic alternatives, including a potential acquisition, merger, business combination, or other strategic transaction. The terms of any strategic transaction that we might enter into could result in the issuance of securities in the company, such as our common stock, which could result in significant dilution to our stockholders. Additionally, in connection with such strategic alternatives, we may seek to raise additional capital through a combination of public and private equity offerings or other financing arrangements. To the extent that we enter into a strategic transaction and/or raise additional capital through the sale of equity, convertible debt securities or other equity-based derivative securities, your ownership interest will be diluted and the terms may include liquidation or other preferences that adversely affect your rights as a stockholder. Any additional indebtedness we incur would result in increased fixed payment obligations and could involve restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. Furthermore, the issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our common stock to decline and existing stockholders may not agree with our strategic or financing plans or the terms of such strategic transaction or financings. If we raise additional funds through strategic partnerships and alliances and licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, or our product candidates, or grant licenses on terms unfavorable to us. Adequate additional financing may not be available to us on acceptable terms, or at all.

Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

We were founded in November 2015. Our operations to date have been limited to corporate organization, recruiting key personnel, business planning, raising capital, acquiring rights to our technology, identifying potential product candidates, undertaking preclinical studies and planning and supporting clinical trials of certain of our product candidates and establishing research and development and manufacturing capabilities. We have not yet demonstrated the ability to complete clinical trials of our product candidates, obtain marketing approvals, manufacture products on a commercial scale or conduct sales and marketing activities necessary for successful commercialization. Consequently, any predictions you make about our future success or viability, should we resume development of our programs, may not be as accurate as they could be if we had a longer operating history. In addition, as an early-stage company, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors.

Adverse developments affecting the financial services industry, such as actual events or concerns involving liquidity, defaults, or non-performance by financial institutions or transactional counterparties, could adversely affect the Company’s current and projected business operations and its financial condition and results of operations.

Actual events involving limited liquidity, defaults, non-performance or other adverse developments that affect financial institutions, transactional counterparties or other companies in the financial services industry or the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, have in the past and may in the future lead to market-wide liquidity problems. Uncertainty remains over liquidity concerns in the broader financial services industry, and if any of our contract organizations, vendors, suppliers or other parties with whom we conduct business are unable to access funds pursuant to their own arrangements with such a financial institution, such party’s ability to perform their obligations could be adversely affected. Similar impacts have occurred in the past, such as during the 2008-2010 financial crisis.

Inflation and rapid increases in interest rates have led to a decline in the trading value of previously issued government securities with interest rates below current market interest rates. Although the U.S. Department of Treasury, FDIC and Federal Reserve Board have announced a program to provide up to $25 billion of loans to financial institutions secured by certain of such government securities held by financial institutions to mitigate the risk of potential losses on the sale of such instruments, widespread demands for customer withdrawals or other liquidity needs of financial institutions for immediately liquidity may exceed the capacity of such program. Additionally, there is no guarantee that the U.S. Department of Treasury, FDIC and Federal Reserve Board will provide

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access to uninsured funds in the future in the event of the closure of other banks or financial institutions, or that they would do so in a timely fashion.

Although we assess our banking relationships as we believe necessary or appropriate, our access to funding sources and other credit arrangements in amounts adequate to finance or capitalize our current and projected future business operations could be significantly impaired by factors that affect our company, the financial institutions with which we have credit agreements or arrangements directly, or the financial services industry or economy in general. These factors could include, among others, events such as liquidity constraints or failures, the ability to perform obligations under various types of financial, credit or liquidity agreements or arrangements, disruptions or instability in the financial services industry or financial markets, or concerns or negative expectations about the prospects for companies in the financial services industry. These factors could involve financial institutions or financial services industry companies with which we have financial or business relationships, but could also include factors involving financial markets or the financial services industry generally.

The results of events or concerns that involve one or more of these factors could include a variety of material and adverse impacts on our current and projected business operations and our financial condition and results of operations. These could include, but may not be limited to, the following:

•Delayed access to deposits or other financial assets or the uninsured loss of deposits or other financial assets;

•Delayed or lost access to, or reductions in borrowings available under revolving existing credit facilities or other working capital sources and/or delays, inability or reductions in the company’s ability to refund, roll over or extend the maturity of, or enter into new credit facilities or other working capital resources;

•Potential or actual breach of contractual obligations that require the Company to maintain letters of credit or other credit support arrangements;

•Potential or actual breach of financial covenants in our credit agreements or credit arrangements;

•Potential or actual cross-defaults in other credit agreements, credit arrangements or operating or financing agreements; or

•Termination of cash management arrangements and/or delays in accessing or actual loss of funds subject to cash management arrangements.

In addition, investor concerns regarding the U.S. or international financial systems could result in less favorable commercial financing terms, including higher interest rates or costs and tighter financial and operating covenants, or systemic limitations on access to credit and liquidity sources, thereby making it more difficult for us to acquire financing on acceptable terms or at all. Any decline in available funding or access to our cash and liquidity resources could, among other risks, adversely impact our ability to meet our operating expenses, financial obligations or fulfill our other obligations, result in breaches of our financial and/or contractual obligations or result in violations of federal or state wage and hour laws. Any of these impacts, or any other impacts resulting from the factors described above or other related or similar factors not described above, could have material adverse impacts on our liquidity and our current and/or projected business operations and financial condition and results of operations.

In addition, any further deterioration in the macroeconomic economy or financial services industry could lead to losses or defaults by our contract organizations, vendors, suppliers or other parties with whom we conduct business, which in turn, could have a material adverse effect on our current and/or projected business operations and results of operations and financial condition. For example, contract organizations, vendors, suppliers or other parties with whom we conduct business could be adversely affected by any of the liquidity or other risks that are described above as factors that could result in material adverse impacts on our company, including but not limited to delayed access or loss of access to uninsured deposits or loss of the ability to draw on existing credit facilities involving a troubled or failed financial institution. Any bankruptcy or insolvency involving our contract organizations, vendors, suppliers or other parties with whom we conduct business, or any breach or default by such parties, or the loss of any significant relationships with such parties, could result in a material adverse impact on our business.

Risks related to the discovery and development of our product candidates

Business interruptions resulting from the coronavirus disease, or COVID-19, pandemic or similar public health crises have caused and may in the future cause a disruption of the development of our product candidates and adversely impact our business.

Public health crises such as pandemics, epidemics, or any outbreak of an infectious disease or similar public health crises could adversely impact our business. For example, the COVID-19 pandemic disrupted normal business operations both in and outside of affected areas and has had significant negative impacts on businesses and financial markets worldwide. While we currently have no ongoing clinical development activities following our decision to halt our clinical development programs while we consider strategic alternatives, we continue to monitor our operations and follow applicable government recommendations, and the majority of our employees have adopted a “hybrid” work schedule which generally limits the number of people in our office at any particular time.

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Notwithstanding these measures, the COVID-19 pandemic, including potential outbreaks of new variants, or any other public health crisis could affect the health and availability of our workforce as well as those of the third parties on which we rely. If members of our management and other key personnel are unable to perform their duties or have limited availability due any outbreak of an infectious disease or similar public health crises, we may not be able to execute on our business strategy and/or our operations may be negatively impacted.

In addition, clinical trial activities, should we resume any such activities, including patient enrollment and data collection, are dependent upon global clinical trial sites which were adversely affected by the COVID-19 pandemic. For example, as the global healthcare community responded to the fluctuations in COVID-19 cases and hospitalizations, many hospitals, including our clinical sites, temporarily paused elective procedures, which included dosing of new patients with our investigational gene therapies. While we substantially resumed data collection and dosing of new patients until halting our development programs in July 2023, our ability to continue clinical activities without further delay or interruption, should we resume development of our programs, will depend on future developments that are highly uncertain and cannot be accurately predicted.

Additional factors from any public health crisis that may delay or otherwise adversely affect enrollment in or the progress of the clinical trials of our product candidates if we resume development of our programs, as well as our business generally, include:

•the potential diversion of healthcare resources away from the conduct of clinical trials to focus on pandemic concerns, including the attention of physicians serving as our clinical trial investigators, hospitals serving as our clinical trial sites and hospital staff supporting the conduct of our clinical trials;

•limitations on travel that could interrupt key trial activities, such as clinical trial site initiations and monitoring, domestic and international travel by employees, contractors or patients to clinical trial sites, including any government-imposed travel restrictions or quarantines that may impact the ability or willingness of patients, employees or contractors to travel to our clinical trial sites or secure visas or entry permissions, any of which could delay or adversely impact the conduct or progress of our clinical trials;

•interruption in global shipping affecting the transport of clinical trial materials, such as patient samples, investigational drug product and conditioning drugs and other supplies used in our clinical trials;

•business disruptions caused by workplace, laboratory and office closures and an increased reliance on employees working from home, disruptions to or delays in ongoing laboratory experiments and operations, staffing shortages, travel limitations or mass transit disruptions, any of which could adversely impact our business operations or those of third party service providers, contractors, or suppliers on whom we rely, impair the productivity of our personnel, subject us to additional cybersecurity risks, create data accessibility problems, cause us to become more susceptible to communication disruptions, or delay necessary interactions with local regulators, ethics committees and other important agencies and contractors;

•business disruptions involving our third parties on whom we rely, including CROs and other collaborators for the conduct of our clinical trials or our third party suppliers or manufacturers, which could impact their ability to perform adequately or disrupt our supply chain; and

•changes in hospital or research institution policies or government regulations, which could delay or adversely impact our ability to conduct our clinical trials.

These and other factors arising from public health crises could reemerge or worsen and adversely impact our ability to conduct clinical trials and our business generally, and could have a material adverse impact on our operations and financial condition and results. The extent to which any public health crisis impacts our operations or those of our third party partners will depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration of the public health crisis, the efficacy and safety of vaccines, including against emerging variants, the ability of third parties to manufacture and distribute vaccines, among others.

Our HSC lentiviral-based gene therapy product candidates are based on a novel technology, which makes it difficult to predict the time and cost of product candidate development and of subsequently obtaining regulatory approval, should we resume development of our product candidates.

We have concentrated our research and development efforts on our HSC gene therapy approach, and should we resume development of our product candidates our future success would depend on our successful development of viable gene therapy product candidates. There can be no assurance that we will not experience problems or delays in developing new product candidates, should we resume development of our product candidates, and that such problems or delays will not cause unanticipated costs, or that any such development problems can be solved. For example, timely enrollment in our clinical trials is dependent upon global clinical trial sites which were adversely affected by the COVID-19 pandemic. In addition, we may also experience delays in developing a sustainable, reproducible and scalable manufacturing process or transferring that process to commercial, additional or alternative

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partners, which should we resume development of our product candidates may prevent us from completing clinical studies or commercializing our products on a timely or profitable basis, if at all. For example, as of July 12, 2023, the date on which we announced that we were halting all further development activities in our programs, we had only dosed 11 patients using our plato platform, including six patients in our FAB-GT clinical trial (for which we previously halted enrollment) and five patients in our Guard1 clinical trial. Our implementation of the LV2 lentiviral vector or of our cell processing to an industrialized, automated closed system using disposable supplies may not be successful or may experience unforeseen delays, should we resume development of our product candidates, which may cause shortages or delays in the supply of our products available for clinical trials and future commercial sales, if any, or impair our research and development efforts, including those in any future clinical trials. In addition, there is no assurance that products using our proprietary LV2 lentiviral vector or manufactured using this automated system will ultimately achieve the same favorable preliminary results observed to date. Furthermore, the FDA generally prefers that clinical trials be double-blinded and potentially include sham controls. Such a trial design could be challenging to implement due to the nature of the treatment regimen of HSC gene therapy.

In addition, the clinical trial requirements of the FDA and other foreign regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of such product candidates. The regulatory approval process for novel product candidates such as ours can be more expensive and take longer than for other, better known or more extensively studied product candidates. To date, only a limited number of HSC gene therapies have received marketing authorization from the FDA or foreign regulatory authorities. Should we resume development of our product candidates, it is difficult to determine how long it would take or how much it would cost to obtain regulatory approvals for those product candidates in the United States, Canada, Europe, Japan or other major markets or how long it would take to commercialize those product candidates, if any were to be approved. Approvals by foreign regulatory authorities may not be indicative of what the FDA may require for approval, and vice versa.

Gene therapy clinical trials conducted at institutions that receive funding for recombinant DNA research from the United States National Institutes of Health, or NIH, also are subject to the NIH Guidelines, under which supervision of human gene transfer trials includes evaluation and assessment by an institutional biosafety committee, or IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. Before a clinical trial can begin at any institution, that institution’s review board, or IRB, and its IBC assesses the safety of the research and identifies any potential risk to public health or the environment. While the NIH guidelines are not mandatory unless the research in question is being conducted at or sponsored by institutions receiving NIH funding of recombinant or synthetic nucleic acid molecule research, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them. Although the FDA decides whether individual gene therapy protocols may proceed, the review process and determinations of other reviewing bodies can impede or delay the initiation of a clinical trial, even if the FDA has reviewed the trial and approved its initiation. In addition, adverse developments in clinical trials of gene therapy products conducted by others may cause the FDA or other oversight bodies to change the requirements for approval of any of our product candidates should we resume their development. Similarly, foreign regulatory authorities may issue new guidelines concerning the development and marketing authorization for gene therapy medicinal products and require that we comply with these new guidelines.

The FDA, NIH and the European Medicines Agency, or EMA, have each expressed interest in further regulating biotechnology, including gene therapy and genetic testing. For example, the EMA advocates a risk-based approach to the development of a gene therapy product. Agencies at both the federal and state level in the United States, as well as the U.S. congressional committees and other governments or governing agencies, have also expressed interest in further regulating the biotechnology industry. For example, in 2016, the FDA established the Office of Tissues and Advanced Therapies, or OTAT, within the CBER, to consolidate the review of gene therapy and related products, and to advise the CBER on its review. In September 2022, the FDA announced retitling of OTAT to the Office of Therapeutic Products, or OTP, and elevation of OTP to a “Super Office” to meet its growing cell and gene therapy workload. Although FDA has indicated that this change of name and responsibilities is intended to, among other things, increase review capabilities and enhance expertise on new cell and gene therapies, we cannot be certain that this approach will improve the time and cost associated with navigating gene therapy regulatory requirements, our regulatory strategy or the potential success of our product candidates. Such regulatory action and developments could, instead, delay, impede or even prevent commercialization of some or all of our product candidates.

These regulatory review committees and advisory groups and any new guidelines they promulgate may lengthen the regulatory review process, require us to perform additional studies, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval and commercialization of these product candidates or lead to significant post-approval limitations or restrictions. Should we resume development of our product candidates, we will be required to consult with these regulatory and advisory groups, and comply with applicable guidelines. If we fail to do so, we may be required to delay or discontinue development of certain of those product candidates. These additional processes may result in a review and approval process that is longer than we otherwise would have expected. Should we resume development of our product candidates, the delay or failure to obtain, or unexpected costs in obtaining, the regulatory approval necessary to bring a potential product to market could decrease our ability to generate sufficient product revenue, and our business, financial condition, results of operations and prospects would be materially and adversely affected.

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The FDA continues to develop its guidance for assessing gene and cell therapy products. For example, the agency has released a series of draft and final guidance documents relating to, among other topics, various aspects of gene therapy product development, review, and approval, including aspects relating to clinical and manufacturing issues related to gene therapy products. In January 2020, the FDA released a final guidance with recommendations for long-term follow-up studies of patients following human gene therapy administration due to the increased risk of undesirable and unpredictable outcomes with gene therapies that may present as delayed adverse events. Foreign regulatory agencies also may have requirements for long term follow-up studies of patients following human gene therapy administration.

Our product candidates and the process for administering our product candidates may cause undesirable side effects or have other properties that, should we resume development of our product candidates, could delay or prevent their regulatory approval, limit their commercial potential or result in significant negative consequences following any potential marketing approval.

During the conduct of clinical trials, patients may experience changes in their health, including illnesses, injuries, discomforts or a fatal outcome. It is possible that as we test our product candidates in larger, longer and more extensive clinical programs, or as use of our product candidates becomes more widespread if they receive regulatory approval, illnesses, injuries, discomforts and other adverse events that were observed in earlier clinical trials, as well as conditions that did not occur or went undetected in previous clinical trials, will be reported by patients. Additionally, any early access to the Company’s investigational therapies, such as through expanded or Right to Try access or compassionate use, may lead to discovery of undesirable side effects, or other negative consequences that could have adverse impacts on our development programs for our product candidates. Gene therapies are also subject to the potential risk that occurrence of adverse events will be delayed following administration of the gene therapy due to persistent biological activity of the genetic material or other components of the vectors used to carry the genetic material. Many times, side effects are only detectable after investigational products are tested in larger scale, pivotal clinical trials or, in some cases, after they are made available to patients on a commercial scale after approval. FDA guidance advises that patients treated with gene therapies undergo long-term follow-up observation for potential adverse events for as long as 15 years. If additional clinical or long-term follow-up experience indicates that any of our product candidates have side effects or cause serious or life-threatening side effects, we may be unable to resume our development programs and any further development of the product candidate may ultimately fail or be delayed.

Gene therapy is still a relatively new approach to disease treatment and adverse side effects could develop. A safety concern for gene therapies using lentiviral vectors has been the possibility of insertional oncogenesis, leading to malignant transformation of transduced cells and cellular outgrowth. As more patients are dosed with HSC gene therapies, it is expected that very rare cases of insertional oncogenesis may occur. For example, several patients with cerebral adrenoleukodystrophy treated in a third-party lentiviral gene therapy clinical trial have been diagnosed with treatment-related myelodysplastic syndrome to date. In addition, persistent clonal dominance due to vector integration has been observed in third-party HSC gene therapy clinical trials. While our HSC gene therapy approach has been designed to avoid insertional oncogenesis, there can be no assurance that patients will not experience such adverse effects, including death. Should we resume development of our gene therapy product candidates and any of those product candidates demonstrates adverse side effects at unacceptable rates or degrees of severity, we may decide or be required to halt or delay clinical development of such product candidates.

In addition to side effects caused by our product candidates, the conditioning, administration process or related procedures, also can cause adverse side effects. A gene therapy patient is generally administered one or more myeloablative drugs to remove stem cells from the bone marrow to create sufficient space in the bone marrow for the modified gene-corrected stem cells to engraft and produce their progeny. This procedure causes side effects and, among other potential risks, can transiently compromise the patient’s immune system, known as neutropenia, and reduce blood clotting, known as thrombocytopenia.

In 2019, we began transitioning, in connection with our Company-sponsored clinical trials, towards a new conditioning regimen for our product candidates utilizing busulfan as the myeloablative conditioning agent instead of the melphalan that we previously used. The use of this conditioning regimen we designed to utilize a precision dosing program, called TCI, to achieve a balance between the removal of a sufficient amount of bone marrow cells from a patient to aid engraftment of our genetically modified cells against potential risks, such as toxicity or graft failure. Our conditioning regimens may not be successful or may nevertheless result in adverse side effects. For example, busulfan, the myeloablative agent most recently used in our conditioning regimen, has been known to carry certain safety risks, including the risk of impairment to fertility in both men and women, and such impairment has been reported in some patients in our clinical trials. Moreover, in each of our previous clinical trials several adverse events, including suppression of neutrophils and platelet counts following the conditioning process, have been observed. While such adverse events in connection with conditioning are expected, if in the future any such adverse events caused by the conditioning process or related procedures continue at unexpected rates or degrees of severity, the FDA or other foreign regulatory authorities could order the cessation of development of, or deny approval of, product candidates for any or all targeted indications. There have been cases of therapy-related myelodysplastic syndrome, a type of blood disorder that is a potential precursor to acute myeloid leukemia, in patients with preexisting cancer where busulfan treatment was posited to be a contributing factor to this secondary malignancy. Even if we are able to demonstrate that adverse events are not product-related, such occurrences could adversely affect patient recruitment (should we resume development of our product candidates) or the ability of enrolled patients to complete the clinical trial, and lead to a decline in our stock price.

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Additionally, if we resume development of our programs and any of our product candidates receives marketing approval, the FDA could require us to adopt a Risk Evaluation and Mitigation Strategy, or REMS, to ensure that the benefits outweigh its risks, which may include, among other things, a medication guide outlining the risks of the product for distribution to patients, a communication plan to health care practitioners, and restrictions on how or where the product can be distributed, dispensed or used. Furthermore, if we or others later identify undesirable side effects caused by our product candidates, several potentially significant negative consequences could result, including:

•regulatory authorities may suspend or withdraw approvals of such product candidate;

•regulatory authorities may require additional or boxed warnings on the label;

•we may be required to change the way a product candidate is distributed, dispensed, or administered or conduct additional clinical trials;

•we could be sued and held liable for harm caused to patients; and

•our reputation may suffer.

Any of these events could prevent us from achieving or maintaining market acceptance of our product candidates, lead to a decline in our stock price, and significantly harm our business, prospects, financial condition and results of operations.

We have never completed a pivotal or registrational clinical trial, and may be unable to do so for any product candidates we may develop, should we resume development of our product candidates.

We are at an early stage of development for all of our product candidates, and have currently halted further development of the Company’s programs. As of the date of this Quarterly Report, only 25 patients have been dosed in our clinical trials, which includes 14 patients from our Fabry program that we deprioritized in January 2022, six patients in our cystinosis program that we sold to Novartis in June 2023, and five patients in our Gaucher disease type 1 program. Should we resume development of our product candidates, further clinical trials must be completed in order to obtain FDA or other regulatory approval to market these product candidates. We have limited experience in preparing, submitting and prosecuting regulatory filings, and have not previously submitted a biologics license application, or BLA, for any product candidate. Carrying out later-stage clinical trials is a complicated and lengthy process, and we do not expect that all data from patients participating in the clinical trials will be relevant or meaningful.

In addition, across our Company-sponsored clinical trials we have dosed only four patients in the United States, and our interactions with the FDA have generally been limited. We cannot be certain how many additional clinical trials of any of our product candidates would be required or how such trials should be designed, should we resume development of our programs. In order to commence a clinical trial in the United States, we are required to seek FDA acceptance of an IND for each of our product candidates. We cannot be sure any IND we submit to the FDA, or any similar CTA we submit in other countries, will be accepted. Should we resume development of our product candidates, there can be no assurance that we would be able to submit and secure similar clearances for any of our product candidates. We may also be required to conduct additional preclinical testing prior to filing an IND for any of our product candidates, and the results of any such testing may not be positive. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to a BLA submission and approval of any of our product candidates. We may require more time and incur greater costs than our competitors and may not succeed in obtaining regulatory approvals of product candidates that we develop. Failure to commence or complete, or delays in, the necessary clinical trials, could prevent us from or delay us in commercializing any of our product candidates.

Success in preclinical studies or early clinical trials may not be indicative of results obtained in later trials, should we resume development of our product candidates.

Results from preclinical studies or early clinical trials are not necessarily predictive of future clinical trial results and are not necessarily indicative of final results. There can be no assurance that prior results, such as signals of safety, activity or durability of effect, observed from preclinical studies or clinical trials will be replicated or will continue in ongoing or future studies or trials, should we resume development of any of our programs. Furthermore, preliminary results may not be indicative of the final results of a trial after all data have been collected and analyzed. For example, in January 2022 we announced the deprioritization of our Fabry program due to several factors, including new clinical data showing variable engraftment patterns from the five most recently dosed Phase 2 FAB-GT patients. Although previously reported data from 13 patients treated across our clinical-stage programs had shown durable engraftment out 9 to 54 months, the new data from the five most recently dosed Phase 2 FAB-GT patients were discordant with these other data and showed variable engraftment. Data from three of the five patients showed both a reduction to near baseline levels in alpha-galactosidase A enzyme activity in leukocytes and plasma, and a reduction in vector copy number in whole blood, potentially suggesting resistance to persistent engraftment of the genetically modified cells observed at three to nine months post infusion of AVR-RD-01. Based on our internal assessment, we believe, due to the large degree of heterogeneity in Fabry disease, that in some cases there may be intrinsic resistance to engraftment related to the unique underlying pathophysiology of untreated Fabry disease, potentially caused by the persistently stressed vascular endothelium. However, while this belief is based on a thorough review

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and analysis conducted by the Company, it remains a hypothesis and, should we resume development of our product candidates, there can be no assurance that similar engraftment or other issues will not occur in clinical trials of our other product candidates, which are all based on our technology and the same HSC approach utilized for AVR-RD-01. For example, although we believe the variable engraftment data were caused by factors intrinsic to certain Fabry disease patients and we do not anticipate readthrough to other clinical trials should we resume development of our product candidates, if the variable engraftment data were actually caused, directly or indirectly, by any other factors, including any aspect of our plato platform or the conditioning process, we could see similar issues in other clinical trials.

There is a high failure rate for gene therapy and biologic product candidates proceeding through clinical trials. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials even after achieving promising results in preclinical testing and earlier-stage clinical trials. Data obtained from preclinical and clinical activities are subject to varying interpretations, which may delay, limit or prevent regulatory approval. In addition, the design of a pivotal clinical trial can determine whether its results will support approval of a product and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. Our Company has limited experience in designing and conducting clinical trials and we may be unable to design and execute a clinical trial to support regulatory approval, should we resume development of our product candidates.

We also may experience regulatory delays or rejections as a result of many factors, including due to changes in regulatory policy or the approval of competitive therapies during the period of our product candidate development. Should we resume development of any of our product candidates, those product candidates may fail to show the desired safety and efficacy in clinical development despite positive results in preclinical studies. Any such failure would cause us to abandon the product candidate.

Additionally, the clinical trials performed to date have been open-label studies and have been conducted at a limited number of clinical sites on a limited number of patients. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the investigational product candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. Moreover, patients selected for early clinical studies often include the most severe sufferers and their symptoms may have been bound to improve notwithstanding the new treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware that patients have received treatment and may interpret the information more favorably given this knowledge. As is typical in open-label studies in which interim reports are provided, the safety and efficacy data are regularly reviewed and validated. As a result, certain data may change over time, including reductions or increases in the number of reported safety events, as well as the characterization of the severity or relatedness of safety events, until the database is locked at the end of the study.

Should we resume development of our product candidates, we may find it difficult to enroll patients in our clinical trials, which could delay or prevent us from proceeding with clinical trials of our product candidates.

Should we resume development of our product candidates, the timing and success of our patient enrollment and clinical trial activities would depend on our ability to recruit patients to participate as well as the completion of required follow-up periods. Patients may be unwilling to participate in our gene therapy clinical trials because of negative publicity from adverse events related to the biotechnology or gene therapy fields, competitive clinical trials for similar patient populations, clinical trials in product candidates employing our vectors, the existence of current treatments or for other reasons. In addition, the indications that we have targeted and may in the future target are rare diseases, which may limit the pool of patients that may be enrolled in our clinical trials. Should we resume development of our product candidates, the timeline for recruiting patients, conducting studies and obtaining regulatory approval of our product candidates may be delayed, which could result in increased costs, delays in advancing our product candidates, delays in testing the effectiveness of our product candidates or termination of the clinical trials altogether.

Should we resume development of our product candidates, we may not be able to identify, recruit and enroll a sufficient number of patients, or those with required or desired characteristics, to complete our clinical trials in a timely manner or at all. There can be no assurance we will achieve that goal or any of our other patient enrollment goals should we resume development of our product candidates.

Patient enrollment and trial completion is affected by factors including the:

•size of the patient population and process for identifying patients;

•design of the trial protocol;

•eligibility and exclusion criteria;

•perceived risks and benefits of the product candidate under study;

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•perceived risks and benefits of gene therapy-based approaches to treatment of diseases, including any required pretreatment conditioning regimens;

•availability of competing therapies and clinical trials;

•severity of the disease under investigation;

•availability of genetic testing for potential patients;

•proximity and availability of clinical trial sites for prospective patients;

•ability to obtain and maintain subject consent;

•risk that enrolled patients will drop out before completion of the trial;

•patient referral practices of physicians; and

•ability to monitor patients adequately during and after treatment.

We historically expanded our patient enrollment activities to include patients who reside in a country other than the country where the applicable clinical site is located, and who are required to travel for some or all of the clinical testing and procedures required for patients in the applicable clinical trial. We have encountered and, should we resume development of our product candidates, in the future may continue to encounter logistical and regulatory challenges that could delay or prevent any such international patients from successfully enrolling and completing clinical trial procedures, including delays in processing or obtaining patient travel visas or denials of entry at borders, potential travel disruptions, or de-prioritization or unavailability of resources at clinical sites for non-resident international clinical trial participants, any of which could delay our progress and completion of planned clinical trials and which would have an adverse effect on our business. In addition, once these international patients return to their home country, they may need to travel back to the country where the applicable clinical site is located. If these patients are unwilling or unable to return to the clinical site for testing and procedures, progress and completion of the clinical trial could be delayed or prevented.

Our product candidates were being developed to treat rare conditions. Should we resume development of our product candidates, we would expect to seek initial marketing approvals in the United States, Europe and certain other major markets, including Japan. However, we may not be able to resume, initiate or continue clinical trials if we cannot enroll a sufficient number of eligible patients to participate in the clinical trials required by FDA or other foreign regulatory authorities. Our ability to successfully resume, initiate, enroll and complete a clinical trial in any foreign country is subject to numerous risks unique to conducting business in foreign countries, including:

•difficulty in establishing or managing relationships with contract research organizations, or CROs, clinical study sites and physicians;

•different standards for the conduct of clinical trials;

•the absence in some countries of established groups with sufficient regulatory expertise for review of gene therapy protocols;

•our inability to locate qualified local consultants, physicians and partners; and

•the potential burden of complying with a variety of foreign laws, medical standards and regulatory requirements, including the regulation of pharmaceutical and biotechnology products and treatment.

Should we resume development of our product candidates and if we have difficulty enrolling a sufficient number of patients to conduct our clinical trials, we may need to delay, limit or terminate the resumption or continuation of clinical trials, any of which would have an adverse effect on our business, financial condition, results of operations and prospects.

Should we resume development of our product candidates, we may encounter substantial delays in resuming our clinical trials or we may fail to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities.

Before obtaining marketing approval from regulatory authorities for the sale of our product candidates, we must conduct extensive clinical studies to demonstrate the safety and efficacy of the product candidates in humans. Clinical testing is expensive, time-consuming and uncertain as to outcome. Should we resume development of our product candidates, we cannot guarantee that any clinical studies will be conducted as planned or completed on schedule, if at all. A failure of one or more clinical studies can occur at any stage of testing. Events that may prevent successful or timely completion of clinical development, should we resume any clinical development programs, include:

•delays in reaching a consensus with regulatory agencies on study design;

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•delays in reaching agreement on acceptable terms with prospective CROs and clinical study sites;

•delays in obtaining required IRB approval at each clinical study site;

•delays in recruiting suitable patients to participate in our clinical studies;

•imposition of a clinical hold by regulatory agencies, after an inspection of our clinical study operations or study sites;

•failure by our CROs, other third parties or us to adhere to clinical study requirements;

•failure to perform in accordance with the FDA’s good clinical practices, or GCP, or applicable regulatory guidelines in other countries;

•delays in the testing, validation, manufacturing and delivery of our product candidates to the clinical sites;

•delays in having patients complete participation in a study or return for post-treatment follow-up;

•clinical study sites or patients dropping out of a study;

•the occurrence of serious adverse events associated with the product candidate that are viewed to outweigh its potential benefits; or

•changes in regulatory requirements and guidance that require amending or submitting new clinical protocols.

Should we resume development of our product candidates, any inability to successfully complete preclinical and clinical development could result in additional costs to us or impair our ability to generate revenues. In addition, if we make changes to our product candidates, or if collaborator-sponsored trials utilize different materials or manufacturing processes from ours to generate data, we may need to conduct additional studies to compare or bridge our modified product candidates to earlier versions, which could delay our clinical development plan or marketing approval for our product candidates.

Should we resume development of our product candidates and, following such resumption, if the results of our clinical studies are inconclusive or if there are safety concerns or adverse events associated with our product candidates, we may:

•be delayed in obtaining marketing approval for our product candidates, if at all;

•obtain approval for indications or patient populations that are not as broad as intended or desired;

•obtain approval with labeling or a REMS that includes significant use or distribution restrictions or safety warnings;

•be subject to changes with the way the product is administered;

•be required to perform additional clinical studies to support approval or be subject to additional post-marketing testing requirements;

•have regulatory authorities withdraw their approval of the product or impose restrictions on its distribution in the form of a REMS;

•be subject to the addition of labeling statements, such as warnings or contraindications;

•be sued; or

•experience damage to our reputation.

Any of these events could prevent us from achieving or maintaining market acceptance of our product candidates and impair our ability to commercialize our products.

Should we resume development of our product candidates, even if we complete the necessary preclinical and clinical studies, we cannot predict whether or when we would be able to obtain regulatory approval to commercialize a product candidate, and any approval could be for a narrower indication than anticipated.

We cannot commercialize a product until the appropriate regulatory authorities have reviewed and approved the product candidate. Even if we resume development of our product candidates and they are able to demonstrate safety and efficacy in clinical studies to support submitting such programs for marketing approval, the regulatory agencies may not complete their review processes in a timely manner, or we may not be able to obtain regulatory approval. Additional delays may result if an FDA Advisory Committee or other regulatory authority recommends non-approval or restrictions on approval. In addition, we may experience delays or rejections based upon additional government regulation from future legislation or administrative action, or changes in regulatory agency policy during the period of product development, clinical studies and the review process. Regulatory agencies also may approve a treatment candidate for fewer or more limited indications than requested or may grant approval subject to the performance of post-marketing studies. In addition, regulatory agencies may not approve the labeling claims that are necessary or desirable for the

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successful commercialization of our product candidates. If we are unable to obtain necessary regulatory approvals or labeling claims, our business, prospects, financial condition and results of operations would be materially and adversely affected.

Our commercially-scalable plato platform has been used in only two of our clinical trials and clinical development has been halted.

While we have submitted and, should we resume development of our product candidates, intend to continue to submit comparability studies to the FDA and other regulatory agencies, as needed, with respect to our implementation of our scalable plato platform, there can be no assurance that the FDA or other regulatory agencies will not in the future require us to conduct additional preclinical studies or clinical trials that could result in delays and additional costs in our development or commercialization programs for our product candidates, which could adversely affect our business. Should we resume development of our product candidates, we intend to continue implementing our scalable plato platform, including heightened vector efficiency, our closed, automated manufacturing system and utilization of a customized conditioning regimen, in connection with each of our investigational product candidates. We have developed the plato platform to form the backbone of our commercial programs, with the intent of replacing our original academic platforms with improved solutions for delivering our gene therapy candidates to patients in multiple disease indications. In order to implement this transition, we were and would continue to be required to conduct additional studies to bridge our modified product candidates to earlier versions, including any earlier version that may have been utilized in a collaborator-sponsored clinical study, which could delay clinical development or marketing approvals. Clinical trial delays could also shorten any periods during which we may have the exclusive right to commercialize our product candidates, if approved, or allow our competitors to bring products to market before we do, which could impair our ability to successfully commercialize our product candidates and may harm our business and results of operations.

We face significant competition in our industry and, should we resume development of our product candidates, there can be no assurance that our product candidates, if approved, will achieve acceptance in the market over existing established therapies. In addition, our competitors may develop therapies that are more advanced or effective than ours, which may adversely affect our ability to successfully market or commercialize any of our product candidates, should we resume development of our product candidates.

We operate in a highly competitive segment of the biopharmaceutical market. We face competition from many different sources, including larger pharmaceutical, specialty pharmaceutical and biotechnology companies, as well as from academic institutions, government agencies and private and public research institutions. Should we resume development of our product candidates, our product candidates, if successfully developed and approved, will compete with established therapies, some of which are being marketed by large and international companies. In addition, should we resume development of our product candidates, we expect to compete with new treatments that are under development or may be advanced into the clinic by our competitors. There are a variety of product candidates, including gene therapies, in development for the indications that we are targeting.

Should we resume development of our product candidates, we anticipate competing with biotechnology and pharmaceutical companies, many of which may have significantly greater resources than we do. For example, for Gaucher disease, Sanofi, Pfizer, and Takeda market existing enzyme replacement therapies, or ERTs, that represent the standard of care for Gaucher patients. For Gaucher disease we also expect that we would compete with oral therapies marketed by Johnson & Johnson and Sanofi. Sanofi also markets an enzyme replacement therapy for Pompe disease. In addition, we may compete with other gene therapy companies in our industry such as Freeline Therapeutics, Generation Bio, or Eli Lilly and Company. Freeline Therapeutics, for example, is developing an adeno-associated virus, or AAV based gene therapy for Gaucher disease type 1. Moreover, a number of gene therapy companies have announced preclinical or clinical non-viral and adeno-associated viral based gene therapy programs that, if successful in obtaining regulatory approval, could compete with our gene therapies. For example, several companies including AskBio (a subsidiary of Bayer AG) and Astellas Pharma have clinical programs for late onset Pompe disease and GeneCradle Therapeutics has announced a clinical program for infantile onset Pompe disease.

Many of our competitors have significantly greater financial, product candidate development, manufacturing and marketing resources than we do. Large pharmaceutical and biotechnology companies have extensive experience in clinical testing and obtaining regulatory approval for their products, and mergers and acquisitions within these industries may result in even more resources being concentrated among a smaller number of larger competitors. Established pharmaceutical companies may also invest heavily to accelerate discovery and development of novel therapeutics or to in-license novel therapeutics that could make the product candidates that we develop obsolete. Competition may increase further as a result of advances in the commercial applicability of technologies and greater availability of capital for investment in these industries. Our business would be materially and adversely affected if competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, have broader market acceptance, are more convenient or are less expensive than any product candidate that we may develop.

Even if we obtain regulatory approval of our product candidates, the availability and price of our competitors’ products could limit the demand and the price we are able to charge for our product candidates. We may not be able to implement our business plan if the acceptance of our product candidates is inhibited by price competition or the reluctance of physicians to switch from existing

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methods of treatment to our product candidates, or if physicians switch to other new drug or biologic products or choose to reserve our product candidates for use in limited circumstances.

Should we resume development of our product candidates, we would expect to seek designations for our product candidates with the FDA and comparable foreign regulatory authorities that are intended to confer benefits such as a faster development process or an accelerated regulatory pathway. However, there can be no assurance that we could successfully obtain such designations. In addition, even if one or more of our product candidates are granted such designations, we may not be able to realize the intended benefits of such designations.

The FDA and comparable foreign regulatory authorities offer certain designations for product candidates that are designed to encourage the research and development of product candidates that are intended to address conditions with significant unmet medical need. These designations may confer benefits such as additional interaction with regulatory authorities, a potentially accelerated regulatory pathway and priority review. However, there can be no assurance that we will successfully obtain such designations for any of our product candidates. In addition, while such designations could expedite the development or approval process, they generally do not change the standards for approval. Even if we obtain such designations for one or more of our product candidates, there can be no assurance that we will realize their intended benefits.

We may seek a Breakthrough Therapy Designation for some of our product candidates should we resume development of our product candidates. A breakthrough therapy is defined as a therapy that is intended, alone or in combination with one or more other therapies, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the therapy may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For therapies that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Therapies designated as breakthrough therapies by the FDA are also eligible for accelerated approval. Designation as a breakthrough therapy is within the discretion of the FDA. Accordingly, even if we believe one of our product candidates meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of a Breakthrough Therapy Designation for a product candidate may not result in a faster development process, review or approval compared to therapies considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our product candidates qualify as breakthrough therapies, the FDA may later decide that such product candidates no longer meet the conditions for qualification.

Should we resume development of our product candidates, we may seek an accelerated approval pathway for one or more of our product candidates from the FDA or comparable foreign regulatory authorities. The FDA may grant accelerated approval to a therapeutic candidate designed to treat a serious or life-threatening condition that provides meaningful therapeutic benefit over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. If granted, accelerated approval is usually contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug’s clinical benefit, and the FDA is permitted to require, as appropriate, that such studies be underway prior to approval or within a specified period after the date of approval. Sponsors must also update FDA on the status of these studies, and under FDORA, the FDA has increased authority to withdraw approval of a drug granted accelerated approval on an expedited basis if the sponsor fails to conduct such studies in a timely manner, send the necessary updates to the FDA, or if such post-approval studies fail to verify the drug’s predicted clinical benefit.

Should we resume development of our product candidates, prior to seeking accelerated approval, we would expect to seek feedback from the FDA or comparable foreign regulatory authorities and would otherwise evaluate our ability to seek and receive such accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we would decide to pursue or submit a BLA for accelerated approval or any other form of expedited development, review or approval. Similarly, there can be no assurance that after subsequent feedback from the FDA or comparable foreign regulatory authorities, we would continue to pursue or apply for accelerated approval or any other form of expedited development, review or approval, even if we initially decide to do so. Furthermore, if we decide to submit an application for accelerated approval, there can be no assurance that such application will be accepted or that any approval will be granted on a timely basis, or at all. The FDA, EMA or other comparable foreign regulatory authorities could also require us to conduct further studies prior to considering our application or granting approval of any type, including, for example, if other products are approved via the accelerated pathway and subsequently converted by FDA to full approval. A failure to obtain accelerated approval or any other form of expedited development, review or approval for our product candidate would result in a longer time period to commercialization of such product candidate, could increase the cost of development of such product candidate and could harm our competitive position in the marketplace. Moreover, even if we are able to obtain accelerated approval for any of our product candidates, there is no guarantee that post-approval studies will be able to confirm the clinical benefit, which could cause FDA to withdraw our approval.

Should we resume development of our product candidates, we may also pursue programs or designations from foreign regulatory authorities, such as the UK’s Innovative Licensing and Access Pathway, or ILAP, which aims to accelerate the time to

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market and facilitate patient access to certain types of medicinal products in development which target a life-threatening or seriously debilitating condition, or where there is a significant patient or public health need. To access the ILAP, an applicant applies for an Innovation Passport designation. Once an Innovation Passport designation is granted, the MHRA and its partner agencies (including The All Wales Therapeutics and Toxicology Centre, National Institute for Health and Care Excellence, or NICE, and the Scottish Medicines Consortium, or SMC) will work with the Innovation Passport designee to define a Target Development Profile, or TDP. The TDP sets out a unique product-specific roadmap towards patient access in the UK, and provides access to a toolkit to support all stages of the design, development and approvals process, including continuous benefit-risk assessment, increased support for novel development approaches and enhanced patient engagement. However, although the goal of the ILAP is to reduce the time to market and enable earlier patient access, access does not accelerate conduct of clinical trials or mean that the regulatory requirements are less stringent, nor does it ensure that a marketing authorization application will be approved or that any approval will be granted within a particular timeframe or at all.

In addition, should we resume development of our product candidates, we may seek Fast Track Designation for some of our product candidates. If a therapy is intended for the treatment of a serious or life-threatening condition and the therapy demonstrates the potential to address unmet medical needs for this condition, the therapy sponsor may apply for Fast Track Designation. However, the FDA has broad discretion whether or not to grant Fast Track designation, so even if we believe a product candidate is eligible for this designation, there can be no assurance that the FDA would decide to grant it. Even if we do receive Fast Track Designation, we may not experience a faster development process, review or approval compared to conventional FDA procedures, and receiving a Fast Track Designation does not provide assurance of ultimate FDA approval. In addition, the FDA may withdraw Fast Track Designation if it believes that the designation is no longer supported by data from our clinical development program.

In addition, should we resume development of our product candidates, we may seek a regenerative medicine advanced therapy, or RMAT, designation for some of our product candidates. An RMAT is defined as cell therapies, therapeutic tissue engineering products, human cell and tissue products, and combination products using any such therapies or products. Gene therapies, including genetically modified cells that lead to a durable modification of cells or tissues may meet the definition of a regenerative medicine therapy. The RMAT program is intended to facilitate efficient development and expedite review of RMATs, which are intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition. A new drug application or a BLA for an RMAT may be eligible for priority review or accelerated approval through (1) surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit or (2) reliance upon data obtained from a meaningful number of sites. Benefits of such designation also include early interactions with FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A regenerative medicine therapy that is granted accelerated approval and is subject to post-approval requirements may fulfill such requirements through the submission of clinical evidence, clinical studies, patient registries, or other sources of real-world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval monitoring of all patients treated with such therapy prior to its approval. RMAT designation is within the discretion of the FDA. Accordingly, even if we believe one of our product candidates meets the criteria for designation as a regenerative medicine advanced therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of RMAT designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our product candidates qualify for RMAT designation, the FDA may later decide that the biological products no longer meet the conditions for qualification.

Should we resume development of our product candidates, we may be unable to obtain orphan drug designation for our product candidates and, even if we obtain such designation, we may not be able to realize the benefits of such designation, including potential marketing exclusivity of our product candidates, if approved.

Regulatory authorities in some jurisdictions, including the United States and other major markets, may designate drugs intended to treat conditions or diseases affecting relatively small patient populations as orphan drugs. Under the Orphan Drug Act of 1983, the FDA may designate a product candidate as an orphan drug if it is intended to treat a rare disease or condition, which is generally defined as having a patient population of fewer than 200,000 individuals in the United States, or a patient population greater than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug will be recovered from sales in the United States. In the European Union, the EMA’s Committee for Orphan Medicinal Products may designate a medicinal product as an orphan medicinal product if it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition affecting not more than 5 in 10,000 persons in the European Union. Additionally, orphan designation may be granted for products intended for the diagnosis, prevention or treatment of a life-threatening, seriously debilitating or serious and chronic condition when, without incentives, it is unlikely that sales of the product in the European Union would be sufficient to justify the necessary investment in developing the product. In either case, the applicant must be able to establish that there is no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the European Union, or if such a method exists, the product would be of a significant benefit to those affected by the condition.

If we request orphan drug designation (or the foreign equivalent) for product candidates, there can be no assurances that the FDA or applicable foreign regulatory authorities will grant such designation. Additionally, the designation of any of our product candidates as an orphan product does not mean that any regulatory agency will accelerate regulatory review of, or ultimately approve,

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that product candidate, nor does it limit the ability of any regulatory agency to grant orphan drug designation to product candidates of other companies that treat the same indications as our product candidates prior to our product candidates receiving exclusive marketing approval.

Generally, if a product candidate with an orphan drug designation receives the first marketing approval for the indication for which it has such designation, the product is entitled to a period of marketing exclusivity, which precludes the FDA or foreign regulatory authorities from approving another marketing application for a product that constitutes the same drug treating the same indication for that marketing exclusivity period, except in limited circumstances. If another sponsor receives such approval before we do (regardless of our orphan drug designation), we will be precluded from receiving marketing approval for our product for the applicable exclusivity period. The applicable period is seven years in the United States and 10 years in the European Union. The exclusivity period in the European Union can be reduced to six years if a product no longer meets the criteria for orphan designation or if the product is sufficiently profitable so that market exclusivity is no longer justified. The European Commission introduced a legislative proposal in April 2023 that, if implemented, could reduce the current ten-year marketing exclusivity period in the European Union for certain orphan medicines to nine years (or five years for well-established use orphan medicines). Orphan drug exclusivity may be revoked if any regulatory agency determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the product to meet the needs of patients with the rare disease or condition.

Even if we obtain orphan drug exclusivity for a product candidate, that exclusivity may not effectively protect the product candidate from competition because different drugs can be approved for the same condition in the United States. Even after an orphan drug is approved, the FDA may subsequently approve another drug for the same condition if the FDA concludes that the latter drug is not the same drug or is clinically superior in that it is shown to be safer, more effective or makes a major contribution to patient care. In the European Union, a marketing authorization may be granted to a similar medicinal product for the same orphan indication at any time if:

•the second applicant can establish in its application that its medicinal product, although similar to the orphan medicinal product already authorized, is safer, more effective or otherwise clinically superior;

•the holder of the marketing authorization for the original orphan medicinal product consents to a second orphan medicinal product application; or

•the holder of the marketing authorization for the original orphan medicinal product cannot supply sufficient quantities of orphan medicinal product.

A marketing application for a product candidate with rare pediatric disease designation, or RPDD, if approved, may not meet the eligibility criteria for a Priority Review Voucher, or PRV, or the RPDD program may sunset before the FDA is able to consider eligibility for a voucher.

Designation of a drug or biologic as a product for a rare pediatric disease does not guarantee that a BLA for such drug or biologic will meet the eligibility criteria for a rare pediatric disease PRV at the time the application is approved. Under the Federal Food, Drug, and Cosmetic Act, should we resume development of our product candidates, we would need to request a rare pediatric disease PRV in our original BLA for any of our product candidates that previously received RPDD. The FDA may determine that any such BLA, if approved, does not meet the eligibility criteria for a PRV, including for the following reasons:

•The disease indication no longer meets the definition of a rare pediatric disease;

•the BLA contains an active ingredient that has been previously approved in a BLA;

•the BLA is not deemed eligible for priority review;

•the BLA does not rely on clinical data derived from studies examining a pediatric population and dosages of the drug intended for that population (that is, if the BLA does not contain sufficient clinical data to allow for adequate labeling for use by the full range of affected pediatric patients); or

•the BLA is approved for a different adult indication than the rare pediatric disease for which the product candidate is designated.

•The authority for the FDA to award rare pediatric disease PRVs for drugs that have received rare pediatric disease designation prior to September 30, 2024 currently expires on September 30, 2026. If the BLA for any of our product candidates with RPDD is not approved prior to September 30, 2026 for any reason, regardless of whether it meets the criteria for a rare pediatric disease PRV, it will not be eligible for a PRV. However, it is also possible the authority for FDA to award rare pediatric disease PRVs will be further extended through federal lawmaking.

Should we resume development of our product candidates, even if we obtain regulatory approval for a product candidate, our products will remain subject to regulatory oversight.

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Should we resume development of our product candidates, even if we obtain any regulatory approval for our product candidates, they will be subject to ongoing regulatory requirements for manufacturing, labeling, packaging, storage, advertising, promotion, sampling, record-keeping and submission of safety and other post-market information. Any regulatory approvals that we receive for our product candidates also may be subject to a REMS, limitations on the approved indicated uses for which the product may be marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing testing, including Phase 4 clinical trials, and surveillance to monitor the quality, safety and efficacy of the product. For example, the holder of an approved BLA is obligated to monitor and report adverse events and any failure of a product to meet the specifications in the BLA. FDA guidance advises that patients treated with gene therapies undergo long-term follow-up observation for potential adverse events for as long as 15 years. The holder of an approved BLA also must submit new or supplemental applications and obtain FDA approval for certain changes to the approved product, product labeling or manufacturing process. Advertising and promotional materials must comply with FDA rules and are subject to FDA review, in addition to other potentially applicable federal and state laws.

In addition, product manufacturers and their facilities are subject to payment of user fees and continual review and periodic inspections by the FDA and other regulatory authorities for compliance with current good manufacturing practices, or cGMP, requirements and adherence to commitments made in the BLA or foreign marketing application. Manufacturers and manufacturers’ facilities are required to comply with extensive FDA, and comparable foreign regulatory authority, requirements including ensuring that quality control and manufacturing procedures conform to cGMP regulations and applicable product tracking and tracing requirements. If we, or a regulatory authority, discover previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facility where the product is manufactured or disagrees with the promotion, marketing or labeling of that product, a regulatory authority may impose restrictions relative to that product, the manufacturing facility or us, including requiring recall or withdrawal of the product from the market or suspension of manufacturing.

If we fail to comply with applicable regulatory requirements following approval of any of our product candidates, a regulatory authority may:

•issue a warning letter asserting that we are in violation of the law;

•seek an injunction or impose administrative, civil or criminal penalties or monetary fines;

•suspend or withdraw regulatory approval;

•suspend any ongoing clinical trials;

•refuse to approve a pending BLA or comparable foreign marketing application (or any supplements thereto) submitted by us or our strategic partners;

•restrict the marketing or manufacturing of the product;

•seize or detain the product or otherwise require the withdrawal of the product from the market;

•refuse to permit the import or export of products; or

•refuse to allow us to enter into supply contracts, including government contracts.

Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. The occurrence of any event or penalty described above may inhibit our ability to commercialize our product candidates and adversely affect our business, financial condition, results of operations and prospects.

In addition, the FDA’s policies, and those of equivalent foreign regulatory agencies, may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability, which would materially and adversely affect our business, financial condition, results of operations and prospects.

Should we resume development of our product candidates, our focus on developing such product candidates may not yield any commercially viable products, and our failure to successfully identify and develop additional product candidates could impair our ability to grow.

While we initially pursued a growth strategy to identify, develop and market additional product candidates, we have halted further development of the Company’s programs and, should we resume development of our product candidates, we do not anticipate actively seeking additional product candidates beyond our existing product candidates. Should we resume development of our product candidates, we may spend several years completing our development of any particular product candidates, and failure can occur at any stage. The product candidates to which we allocate our resources may not end up being successful. Because we have limited

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resources, we may forego or delay pursuit of opportunities with certain programs or product candidates or for indications that later prove to have greater commercial potential than our product candidates. Our spending on any future research and development programs may not yield any commercially viable product candidates. Should we resume development of our product candidates, if we do not accurately evaluate the commercial potential for a particular product candidate, we may relinquish valuable rights to that product candidate through strategic collaborations, licensing or other arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate. If any of these events occur, we may be forced to abandon our development efforts with respect to a particular product candidate or fail to develop a potentially successful product candidate.

In addition, should we resume development of our product candidates, certain of our product candidates may not demonstrate in patients any or all of the pharmacological benefits we believe they may possess or compare favorably to existing, approved therapies, such as ERT. We have not yet succeeded and may never succeed in demonstrating efficacy and safety of our product candidates in clinical trials or in obtaining marketing approval thereafter. Accordingly, our focus on treating these diseases may not result in the development of commercially viable products.

Should we resume development of our product candidates, if we are unsuccessful in our development efforts, we may not be able to advance the development of our product candidates, commercialize products, raise capital, expand our business or continue our operations.

Risks related to manufacturing

Gene therapies are novel, complex and difficult to manufacture. Should we resume development of our product candidates, we could experience production problems that result in delays in our development or commercialization programs or otherwise adversely affect our business.

The manufacturing process we use to produce our product candidates is complex, novel and has not been validated for commercial use. Should we resume development of our product candidates, several factors could cause production interruptions, including equipment malfunctions, facility contamination, raw material shortages or contamination, natural disasters, disruption in utility services, human error or disruptions in the operations of our suppliers.

Our product candidates require processing steps that are more complex than those required for most chemical pharmaceuticals. Moreover, unlike chemical pharmaceuticals, the physical and chemical properties of a biologic such as ours generally cannot be fully characterized. As a result, assays of the finished product may not be sufficient to ensure that the product will perform in the intended manner. Accordingly, we and our manufacturing suppliers employ multiple steps to control the manufacturing process with the goal of ensuring that the product candidate is made strictly and consistently in compliance with the applicable process and specifications. Problems with the manufacturing process, including even minor deviations from the intended process, could result in product defects or manufacturing failures that result in lot failures, product recalls, product liability claims or insufficient inventory. We may encounter problems achieving adequate quantities and quality of clinical-grade materials that meet FDA or other applicable regulatory standards or specifications with consistent and acceptable production yields and costs.

In addition, the FDA and other foreign regulatory authorities may require us to submit samples of any lot of any approved product together with the protocols showing the results of applicable tests at any time. Under some circumstances, the FDA or other foreign regulatory authorities may require that we not distribute a lot until the agency authorizes its release. Even slight deviations in the manufacturing process, including those affecting quality attributes and stability, may result in unacceptable changes in the product that could result in lot failures or product recalls. Should we resume development of our product candidates, there is no assurance we will not experience lot failures in the future. Lot failures or product recalls could cause us to delay clinical trials, or, if approved, commercial product launches, which could be costly to us and otherwise harm our business, financial condition, results of operations and prospects. Our manufacturing process relies on a platform structure, which we refer to as our plato platform, and, if we experience delays, deviations or failures that impact that platform, such delays, deviations or failures could have an adverse impact on our development products or future commercialization programs.

Risks related to our reliance on third parties

Should we resume development of our product candidates, we expect to rely on third parties to conduct some or all aspects of our vector production, product manufacturing, protocol development, research and preclinical and clinical testing, and these third parties may not perform satisfactorily.

Should we resume development of our product candidates, we do not expect to independently conduct our vector production, product manufacturing, protocol development, research and preclinical and clinical testing. We have historically relied, and, should we resume development of our product candidates, expect to continue to rely, on third parties with respect to these items. Any of these third parties may terminate their engagements with us or renegotiate the terms of our agreements at any time. If we need to enter into alternative arrangements, it could delay our product development activities. Our reliance on these third parties for research and

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development activities will reduce our control over these activities but will not relieve us of our responsibility to ensure compliance with all required regulations and study protocols. For example, for product candidates that we develop and commercialize on our own, we will remain responsible for ensuring that each of our preclinical and clinical studies are conducted in accordance with the study plan, protocols and regulatory requirements.

Even with relevant experience and expertise, our third-party manufacturers may encounter difficulties in production, such as initial production, managing the transition from early to late-stage clinical and commercial manufacturing, and ensuring that the product meets required specifications. These difficulties may include delays, failure or inability achieving production yields, establishing and maintaining stage-appropriate cGMP quality procedures, operator error, shortages of qualified personnel, and compliance with federal, state and foreign regulations. We cannot make any assurances that these difficulties will not occur in the future, or that we will be able to resolve or address them in a timely manner or at all as problems arise.

Should we resume development of our product candidates, if our contract counterparties do not successfully carry out their contractual duties, meet expected deadlines or conduct our studies in accordance with regulatory requirements or our stated study plans and protocols, we will not be able to complete, or may be delayed in completing, the preclinical and clinical studies required to support approval of our product candidates or the FDA or other regulatory agencies may refuse to accept our clinical or preclinical data. For example, in 2019 we encountered delays in the enrollment of patients in the Company-sponsored Guard1 clinical trial of AVR-RD-02 for Gaucher disease. While a number of interested patients had been identified for the Guard1 clinical trial, we encountered patient pre-screening failures that impacted the commencement of enrollment in these studies. Additionally, as a result of the COVID-19 pandemic, in 2020 we encountered protracted timelines with our investigational site startup activities for our Guard1 clinical trial, which also impacted patient enrollment. In 2020, a kidney biopsy was conducted on the third patient in the FAB-GT clinical trial of AVR-RD-01, but due to human error in processing the biopsy sample at the external laboratory vendor, the kidney Gb3 inclusions could not be evaluated and anticipated data was not available.

Should we resume development of our product candidates, reliance on third-party manufacturers entails risks to which we would not be subject if we manufactured the product candidates ourselves, including:

•the inability to negotiate manufacturing agreements with third parties under commercially reasonable terms;

•reduced control as a result of using third-party manufacturers for all aspects of manufacturing activities;

•termination or nonrenewal of manufacturing agreements with third parties in a manner or at a time that is costly or damaging to us; and

•disruptions to the operations of our third-party manufacturers or suppliers caused by conditions unrelated to our business or operations, including the impact of the COVID-19 pandemic or the bankruptcy of the manufacturer or supplier.

Any of these events could lead to delays of our preclinical and clinical studies or failure to obtain regulatory approval, or impact our ability to successfully commercialize future products. Some of these events could be the basis for FDA action, including injunction, recall, seizure or total or partial suspension of production.

We have historically relied, and, should we resume development of our product candidates, expect to continue to rely, on sole source suppliers for our automated, closed cell processing system; vector supply; plasmid supply; cell culture media supply; and drug product manufacturing. In addition, we are dependent on a limited number of suppliers for some of our other components and materials used in our product candidates.

We have moved our cell processing to an automated, closed system with a sole source supplier. In addition, we have historically relied, and, should we resume development of our product candidates, expect to continue to rely, on sole source suppliers for vector supply, plasmid supply and cell culture media, as well as drug product manufacturing for our Company-sponsored clinical trials. Should we resume development of our product candidates, our sole source suppliers may be unwilling or unable to supply product to us reliably, continuously or at the levels we anticipate or are required by our clinical trial activities, or at all. Such suppliers could still delay, suspend, or terminate supply of product to us for a number of reasons, including manufacturing or quality issues, payment disputes with us, intellectual property disputes with third parties, bankruptcy or insolvency, earthquakes or other natural disasters or other occurrences.

In addition, we depend on a limited number of suppliers for some of the other components necessary for our product candidates. Should we resume development of our product candidates, we cannot be sure that any of our suppliers will remain in business, or that they will not be purchased by one of our competitors or another company that is not interested in continuing to produce these materials for our intended purpose. Our use of a sole source or limited number of suppliers of raw materials, components and finished goods exposes us to several risks, including disruptions in supply, price increases, late deliveries and an inability to meet customer demand. There are, in general, relatively few alternative sources of supply for these components and equipment. Any of our vendors may be unable or unwilling to meet our future demands for our clinical trials or commercial sale. Establishing additional or replacement suppliers for these components and materials could take a substantial amount of time and it may be difficult or impossible to establish

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replacement suppliers who meet regulatory requirements. Any disruption in supply from any supplier or manufacturing location could lead to supply delays or interruptions which would damage our business, financial condition, results of operations and prospects.

Should we resume development of our product candidates and we are required to switch to a replacement supplier or manufacture materials ourselves, the manufacture and delivery of our product candidates could be interrupted for an extended period, adversely affecting our business. Establishing additional or replacement suppliers may not be accomplished quickly, and we may not be able to enter agreements with replacement suppliers on reasonable terms, if at all. In either scenario, our clinical trials supply could be delayed significantly as we establish alternative supply sources. In some cases, the technical skills required to manufacture our products or product candidates may be unique or proprietary to the original CMO and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. If we are able to find a replacement supplier, the replacement supplier would need to be qualified and may require additional regulatory authority approval, which could result in further delay. For example, the FDA could require additional supplemental bridging data if we rely upon a new supplier. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials. If we resume development of our product candidates, we would seek to maintain adequate inventory of the components and materials used in our product candidates; however, any interruption or delay in the supply of components or materials, or our inability to obtain components or materials from alternate sources at acceptable prices in a timely manner, could impair our ability to conduct our clinical trials and, if our product candidates are approved, to meet the demand of our customers and cause them to cancel orders.

In addition, as part of the FDA’s approval of our product candidates, the FDA must review and approve the individual components of our production process, which includes the manufacturing processes and facilities of our suppliers. Our current suppliers have not undergone this process, nor have they had any components included in any product approved by the FDA.

Our reliance on suppliers subjects us to a number of risks that, should we resume development of our product candidates, could materially harm our reputation, business, and financial condition, including, among other things:

•delays in production, supply, shipment or delivery as a result of the COVID-19 pandemic or trade sanctions, embargoes, and heightened export requirements resulting from the war in Ukraine and the evolving conflicts in Israel and the Gaza Strip;

•the interruption of supply resulting from modifications to or discontinuation of a supplier’s operations;

•delays in product shipments resulting from uncorrected defects, reliability issues, or a supplier’s variation in a component;

•a lack of long-term supply arrangements for key components with our suppliers;

•the inability to obtain adequate supply in a timely manner, or to obtain adequate supply on commercially reasonable terms;

•difficulty and cost associated with locating and qualifying alternative suppliers for our components in a timely manner;

•production delays related to the evaluation and testing of products from alternative suppliers, and corresponding regulatory qualifications;

•a delay in delivery due to our suppliers prioritizing other customer orders over ours;

•damage to our reputation caused by defective components produced by our suppliers;

•increased cost of our warranty program due to product repair or replacement based upon defects in components produced by our suppliers; and

•fluctuation in delivery by our suppliers due to changes in demand from us or their other customers.

If any of these risks materialize, our costs could significantly increase and our ability to conduct our clinical trials and, if our product candidates are approved, to meet demand for our products could be impacted.

We and our contract manufacturers are subject to significant regulation with respect to manufacturing our products. The manufacturing facilities on which we have relied may not continue to meet regulatory requirements and have limited capacity.

In our development activities to date, we have relied on sole source suppliers of our automated, closed cell processing system; vector supply; plasmid supply; cell culture media; as well as drug product manufacturing for our Company-sponsored clinical trials. In addition, we have depended on a limited number of suppliers for some of the other components necessary for our product candidates. Each of our suppliers may require licenses to manufacture such components if such processes are not owned by the supplier or in the public domain, and we may be unable to transfer or sublicense the intellectual property rights we may have with respect to such activities.

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All entities involved in the preparation of therapeutics for clinical studies or commercial sale, including our existing contract manufacturers for our product candidates, are subject to extensive regulation. Components of a finished therapeutic product approved for commercial sale or used in clinical studies must be manufactured in accordance with cGMP. These regulations govern manufacturing processes and procedures (including record keeping) and the implementation and operation of quality systems to control and assure the quality of investigational products and products approved for sale. Poor control of production processes can lead to the introduction of adventitious agents or other contaminants, or to inadvertent changes in the properties or stability of our product candidates that may not be detectable in final product testing. We or our contract manufacturers must supply all necessary documentation in support of a BLA on a timely basis and must adhere to the FDA’s good laboratory practices, or GLP, and cGMP regulations enforced by the FDA through its facilities inspection program. Some of our contract manufacturers have not produced a commercially-approved product and have never been inspected by the FDA before. Our facilities and quality systems and the facilities and quality systems of some or all of our third-party contractors must pass a pre-approval inspection for compliance with the applicable regulations as a condition of regulatory approval of our product candidates or any of our other potential products. In addition, the regulatory authorities may, at any time, audit or inspect a manufacturing facility involved with the preparation of our product candidates or our other potential products or the associated quality systems for compliance with the regulations applicable to the activities being conducted. If these facilities do not pass a pre-approval plant inspection, or if the FDA is unable to conduct such an inspection due to the COVID-19 pandemic or similar public health crisis, the FDA may issue a complete response letter or defer action on our applications, and approval of the products may be delayed or may not be granted.

The regulatory authorities also may, at any time following approval of a product for sale, audit our manufacturing facilities or those of our third-party contractors. If any such inspection or audit identifies a failure to comply with applicable regulations or if a violation of our product specifications or applicable regulations occurs independent of such an inspection or audit, we or the relevant regulatory authority may require remedial measures that may be costly and/or time-consuming for us or a third party to implement and that may include the temporary or permanent suspension of a clinical study or commercial sales or the temporary or permanent closure of a facility. Any such remedial measures imposed upon us or third parties with whom we contract could materially harm our business.

If we or any of our third-party manufacturers fail to maintain regulatory compliance, the FDA can impose regulatory sanctions including, among other things, refusal to approve a pending application for a new drug product or biologic product, or revocation of a pre-existing approval. As a result, our business, financial condition and results of operations may be materially harmed.

Should we resume development of our product candidates, these factors could cause the delay of clinical studies, regulatory submissions, required approvals or commercialization of our product candidates, cause us to incur higher costs and prevent us from commercializing our products successfully. Furthermore, if our suppliers fail to meet contractual requirements, and we are unable to secure one or more replacement suppliers capable of production at a substantially equivalent cost, our preclinical and clinical studies may be delayed.

Our reliance on third parties requires us to share our trade secrets, which increases the possibility that a competitor will discover them or that our trade secrets will be misappropriated or disclosed.

Because we have relied and, should we resume development of our product candidates, would expect to continue to rely on third parties to manufacture our vectors and our product candidates, and because we collaborate with various organizations and academic institutions on the advancement of our gene therapy approach, we must, at times, share trade secrets with them. We seek to protect our proprietary technology in part by entering into confidentiality agreements and, if applicable, material transfer agreements, collaborative research agreements, consulting agreements or other similar agreements with our collaborators, advisors, employees and consultants prior to beginning research or disclosing proprietary information. These agreements typically limit the rights of the third parties to use or disclose our confidential information, such as trade secrets.

Despite the contractual provisions employed when working with third parties, the need to share trade secrets and other confidential information increases the risk that such trade secrets become known by our competitors, are inadvertently incorporated into the technology of others, or are disclosed or used in violation of these agreements. Given that our proprietary position is based, in part, on our know-how and trade secrets, a competitor’s discovery of our trade secrets or other unauthorized use or disclosure would impair our competitive position and may have a material adverse effect on our business.

In addition, these agreements typically restrict the ability of our collaborators, advisors, employees and consultants to publish data potentially relating to our trade secrets. Our academic collaborators typically have rights to publish data, provided that we are notified in advance and may delay publication for a specified time in order to secure our intellectual property rights arising from the collaboration. In other cases, publication rights are controlled exclusively by us, although in some cases we may share these rights with other parties. Despite our efforts to protect our trade secrets, our competitors may discover our trade secrets, either through breach of these agreements, independent development or publication of information including our trade secrets in cases where we do not have proprietary or otherwise protected rights at the time of publication. A competitor’s discovery of our trade secrets would impair our competitive position and have an adverse impact on our business.

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Risks related to commercialization of our product candidates

Should we resume development of our product candidates and obtain approval of any of our product candidates, and we are unable to establish sales, distribution and marketing capabilities or enter into agreements with third parties to market and sell our product candidates, we will be unable to generate any product revenue.

To successfully commercialize any of our product candidates, if approved, we will need to develop our commercial capabilities, either on our own or with others, should we resume development of our product candidates. The establishment and development of our own commercial team or the establishment of a contract sales force to market any product candidate we may develop will be expensive and time-consuming and could delay any product launch. Moreover, we cannot be certain that we will be able to successfully develop this capability. We may enter into collaborations regarding any approved product candidates with other entities to utilize their established marketing and distribution capabilities, but we may be unable to enter into such agreements on favorable terms, if at all. If any future collaborators do not commit sufficient resources to commercialize our product candidates, or we are unable to develop the necessary capabilities on our own, we will be unable to generate sufficient product revenue to sustain our business. We compete with many companies that currently have extensive, experienced and well-funded sales, distribution and marketing operations to recruit, hire, train and retain marketing and sales personnel. We also face competition in our search for third parties to assist us with the sales and marketing efforts of our product candidates, if approved. Without an internal team or the support of a third-party to perform marketing and sales functions, we may be unable to compete successfully against these more established companies.

Should we resume development of our product candidates and the market opportunities for our product candidates are smaller than we believe they are, our product revenues may be adversely affected and our business may suffer.

We have historically focused our research and product development on treatments for serious lysosomal disorders. Our understanding of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with our product candidates, are based on estimates. These estimates may prove to be incorrect and new studies may reduce the estimated incidence or prevalence of these diseases. The number of patients in the United States and elsewhere may turn out to be lower than expected or may not be otherwise amenable to treatment with our products, patients may become increasingly difficult to identify and access, and any approval we receive from regulatory agencies may be for a narrower indication and smaller patient population than anticipated, all of which, should we resume development of our product candidates, would adversely affect our business, financial condition, results of operations and prospects.

Should we resume development of our product candidates, the commercial success of any current or future product candidate will depend upon the degree of market acceptance by physicians, patients, third-party payors and others in the medical community.

Should we resume development of our product candidates, and thereafter if we obtain any regulatory approval for our product candidates, the commercial success of our product candidates will depend in part on the medical community, patients, and third-party payors accepting gene therapy products in general, and our product candidates in particular, as effective, safe and cost-effective. Any product that we bring to the market may not gain market acceptance by physicians, patients, third-party payors and others in the medical community. The degree of market acceptance of these product candidates, if approved for commercial sale, will depend on a number of factors, including:

•the potential efficacy and potential advantages over alternative treatments, including any similar generic treatments;

•the efficacy and safety as demonstrated in pivotal clinical trials and published in peer-reviewed journals;

•the prevalence and severity of any adverse events or side effects, including any limitations or warnings contained in a product’s approved labeling or that are later found to be associated with a product, including in findings from long-term follow-up studies;

•the prevalence and severity of any side effects resulting from the conditioning regimen for the administration of our product candidates;

•the ability to offer the products for sale at competitive prices;

•the clinical indications for which the products are approved by the FDA or comparable regulatory agencies;

•the relative convenience and ease of dosing and administration compared to alternative treatments;

•the willingness of the target patient population to try new therapies and of physicians to prescribe these therapies;

•the strength of marketing and distribution support and timing of market introduction of competitive products;

•restrictions on how the product is distributed;

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•the availability of accessible and skilled healthcare centers capable of administering our treatments;

•publicity concerning our products or competing products and treatments; and

•favorable third-party insurance coverage and sufficient reimbursement.

Sales of medical products also depend on the willingness of physicians to prescribe the treatment, which is likely to be based on a determination by these physicians that the products are safe, therapeutically effective and cost effective. In addition, the inclusion or exclusion of products from treatment guidelines established by various physician groups and the viewpoints of influential physicians can affect the willingness of other physicians to prescribe the treatment. We cannot predict whether physicians, physicians’ organizations, hospitals, other healthcare providers, government agencies or private insurers will determine that our product is safe, therapeutically effective and cost effective as compared with competing treatments.

Even if a product candidate displays a favorable efficacy and safety profile in preclinical and clinical studies, market acceptance of the product, if approved for commercial sale, will not be known until after it is launched. Our efforts to educate the medical community and third-party payors on the benefits of our product candidates may require significant resources and may never be successful. Such efforts to educate the marketplace may require more resources than are required by the conventional technologies marketed by our competitors. If these products do not achieve an adequate level of acceptance, we may not generate significant product revenue and may not become profitable.

Should we resume development of our product candidates, if we obtain approval to commercialize our product candidates outside of the United States, a variety of risks associated with international operations could materially adversely affect our business.

We had been conducting clinical trials for our product candidates in the United States, Canada and Australia, and should we resume development of our product candidates, we would expect to expand our clinical trials to other geographies. If any of our product candidates are approved for commercialization, we may enter into agreements with third parties to market them on a worldwide basis or in more limited geographical regions. We expect that we will be subject to additional risks related to entering into international business relationships, including:

•different regulatory requirements for approval of drugs and biologics in foreign countries;

•reduced protection for intellectual property rights;

•unexpected changes in tariffs, trade barriers and regulatory requirements;

•economic weakness, including inflation, fluctuating interest rates, or political instability in particular foreign economies and markets;

•compliance with tax, employment, immigration and labor laws for employees living or traveling abroad;

•foreign currency fluctuations, which could result in increased operating expenses and reduced revenues, and other obligations incident to doing business in another country;

•workforce uncertainty in countries where labor unrest is more common than in the United States;

•production shortages resulting from any events affecting raw material supply or manufacturing capabilities abroad; and

•business interruptions resulting from geopolitical actions, including war and terrorism, or natural disasters including earthquakes, typhoons, floods and fires.

The insurance coverage and reimbursement status of newly-approved products are uncertain. Should we resume development of our product candidates, failure to obtain or maintain adequate coverage and reimbursement for any of our product candidates, if approved, could limit our ability to market those products and decrease our ability to generate revenue.

The regulations that govern marketing approvals, pricing and reimbursement for new drugs vary widely from country to country. In the United States, recently enacted legislation may significantly change the approval requirements in ways that could involve additional costs and cause delays in obtaining approvals. Some countries require approval of the sale price of a drug before it can be marketed. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. As a result, we might obtain marketing approval for a product in a particular country, but then be subject to price regulations that delay our or their commercial launch of the product, possibly for lengthy time periods, and negatively impact the revenue we are able to generate from the sale of the product in that country. Adverse pricing limitations may hinder our ability to recoup our investment in one or more product candidates, even if any product candidates we may develop obtain marketing approval. See section entitled “Business – Government Regulation – Coverage and Reimbursement” in our Annual Report on Form 10-K for the year ended December 31, 2022.

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Should we resume development of our product candidates, and obtain regulatory approval for such candidates, our ability to successfully commercialize our product candidates or any other products that we may develop also will depend in part on the extent to which reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers, and other organizations. Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. The availability and extent of reimbursement by governmental and private payors is essential for most patients to be able to afford treatments. Sales of our product candidates will depend substantially, both domestically and abroad, on the extent to which the costs of our product candidates will be paid by health maintenance, managed care, pharmacy benefit and similar healthcare management organizations, or reimbursed by government health administration authorities, private health coverage insurers and other third-party payors. We may not be able to provide data sufficient to gain acceptance with respect to coverage and reimbursement. If reimbursement is not available, or is available only at limited levels, we may not be able to successfully commercialize our product candidates, if approved. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment.

There is significant uncertainty related to the insurance coverage and reimbursement of newly approved products. In the United States, the principal decisions about reimbursement for new medicines are typically made by Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services, or HHS, as CMS decides whether and to what extent a new medicine will be covered and reimbursed under Medicare. Private payors tend to follow CMS to a substantial degree. It is difficult to predict what CMS will decide with respect to reimbursement for fundamentally novel products such as ours, as there is no body of established practices and precedents for these new products. Patients who are provided medical treatment for their conditions generally rely on third-party payors to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from governmental healthcare programs and commercial payors are critical to new product acceptance. Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, decide which drugs and treatments they will cover and the amount of reimbursement.

A primary trend in the U.S. healthcare industry and elsewhere is cost containment. Government authorities and other third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. Outside the United States, international operations are generally subject to extensive governmental price controls and other market regulations, and we believe the increasing emphasis on cost-containment initiatives in Europe and certain other major markets where we plan to commercialize may put pressure on the pricing and usage of our product candidates. In many countries, the prices of medical products are subject to varying price control mechanisms as part of national health systems, and pricing negotiations with governmental authorities can take considerable time after the receipt of marketing approval for a product. To obtain reimbursement or pricing approval in some countries, we may be required to conduct a clinical trial that compares the cost effectiveness of our product candidates to other available therapies. In general, the prices of medicines under such systems are substantially lower than in the United States. Other countries allow companies to fix their own prices for medicines, but monitor and control company profits. Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our product candidates. Accordingly, in markets outside the United States, the reimbursement for our products may be reduced compared with the United States and may be insufficient to generate commercially reasonable revenues and profits.

Moreover, efforts by governmental and other third-party payors, in the United States and abroad, to cap or reduce healthcare costs may cause such organizations to limit both coverage and level of reimbursement for new products approved and, as a result, they may not cover or provide adequate payment for our product candidates. Should we resume development of our product candidates, we expect to experience pricing pressures in connection with the sale of any of our product candidates, due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcare costs in general, particularly prescription drugs and surgical procedures and other treatments, has become very intense. As a result, increasingly high barriers are being erected to the entry of new products.

Due to the novel nature of our technology and the potential for our product candidates to offer therapeutic benefit in a single administration, we face uncertainty related to pricing and reimbursement for these product candidates should we resume their development.

Should we resume development of our product candidates, our target patient populations are relatively small, as a result of which the pricing and reimbursement of our product candidates, if approved, must be adequate to support commercial infrastructure. If we are unable to obtain adequate levels of reimbursement, our ability to successfully market and sell our product candidates will be adversely affected. The manner and level at which reimbursement is provided for services related to our product candidates (e.g., for administration of our product to patients) is also important. Inadequate reimbursement for such services may lead to physician resistance and adversely affect our ability to market or sell our product candidates, if approved. Moreover, if approved for marketing, because our product candidates are designed to provide their intended therapeutic benefit from a single administration, treatment with our product candidates may result in a decrease in the available pool of target patients.

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Healthcare legislative reform measures and constraints on national budget social security systems may have a material adverse effect on our business and results of operations.

The United States and many foreign jurisdictions have enacted or proposed legislative and regulatory changes affecting the healthcare system that could prevent or delay marketing approval of our product candidates or any future product candidates, restrict or regulate post-approval activities and affect our ability to profitably sell any product for which we obtain marketing approval. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives. There have been, and likely will continue to be, legislative and regulatory proposals at the federal and state levels directed at broadening the availability of healthcare and containing or lowering the cost of healthcare. See Section entitled “Business – Government Regulation – Healthcare Reform” in our Annual Report on Form 10-K for the year ended December 31, 2022.

Should we resume development of our product candidates, the continuing efforts of the government, insurance companies, managed care organizations and other payers of healthcare services to contain or reduce costs of healthcare may adversely affect:

•the demand for any of our product candidates, if approved;

•the ability to set a price that we believe is fair for any of our product candidates, if approved;

•our ability to generate revenues and achieve or maintain profitability;

•the level of taxes that we are required to pay; and

•the availability of capital.

Legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for pharmaceutical and biologic products. We cannot be sure whether additional legislative changes will be enacted, or whether existing regulations, guidance or interpretations will be changed, or what the impact of such changes on the marketing approvals of our product candidates, if any, may be. In addition, increased scrutiny by Congress of the FDA’s approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing testing and other requirements.

Moreover, increasing efforts by governmental and third-party payors in the United States and abroad to cap or reduce healthcare costs may cause such organizations to limit both coverage and the level of reimbursement for newly approved products and, as a result, they may not cover or provide adequate payment for our product candidates. There has been increasing legislative and enforcement interest in the United States with respect to specialty drug pricing practices. Specifically, there have been several recent U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs. The Inflation Reduction Act of 2022, or IRA, includes several provisions that may impact our business to varying degrees, including provisions that reduce the out-of-pocket spending cap for Medicare Part D beneficiaries from $7,050 to $2,000 starting in 2025, thereby effectively eliminating the coverage gap; impose new manufacturer financial liability on certain drugs under Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D price caps for certain high-cost drugs and biologics without generic or biosimilar competition; require companies to pay rebates to Medicare for certain drug prices that increase faster than inflation; and delay until January 1, 2032 the implementation of the HHS rebate rule that would have limited the fees that pharmacy benefit managers can charge. Further, under the IRA, orphan drugs are exempted from the Medicare drug price negotiation program, but only if they have one orphan designation and for which the only approved indication is for that disease or condition. If a product receives multiple orphan designations or has multiple approved indications, it may not qualify for the orphan drug exemption. The implementation of the IRA is currently subject to ongoing litigation challenging the constitutionality of the IRA’s Medicare drug price negotiation program. The effects of the IRA on our business and the healthcare industry in general is not yet known.

In addition, President Biden has issued multiple executive orders that have sought to reduce prescription drug costs. In February 2023, HHS also issued a proposal in response to an October 2022 executive order from President Biden that includes a proposed prescription drug pricing model that will test whether targeted Medicare payment adjustments will sufficiently incentivize manufacturers to complete confirmatory trials for drugs approved through FDA’s accelerated approval pathway. Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and the Biden administration may reverse or otherwise change these measures, both the Biden administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs.

We expect that the healthcare reform measures that have been adopted and may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any approved product and could seriously harm our future revenues. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors. Should we resume development of our product candidates, the implementation of

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cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability or commercialize our product candidates.

Inadequate funding for the FDA and other government agencies could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of other agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA and other government employees and stop critical activities. Since March 2020, when foreign and domestic inspections of facilities were largely placed on hold, the FDA has been working to resume pre-pandemic levels of inspection activities, including routine surveillance, bioresearch monitoring and pre-approval inspections. Should the FDA determine that an inspection is necessary for approval and an inspection cannot be completed during the review cycle due to restrictions on travel, and the FDA does not determine a remote interactive evaluation to be adequate, the FDA has stated that it generally intends to issue, depending on the circumstances, a complete response letter or defer action on the application until an inspection can be completed. During the COVID-19 public health emergency, a number of companies announced receipt of complete response letters due to the FDA’s inability to complete required inspections for their applications. Regulatory authorities outside the U.S. may adopt similar restrictions or other policy measures in response to the COVID-19 pandemic or any other public health crisis and may experience delays in their regulatory activities. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, should we resume development of our product candidates, which could have a material adverse effect on our business. Further, future shutdowns of other government agencies, such as the SEC, may also impact our business through review of our public filings and our ability to access the public markets.

Should we resume development of our product candidates, any contamination in our manufacturing process, shortages of materials or failure of any of our key suppliers to deliver necessary components could result in interruption in the supply of our product candidates and delays in our clinical development or commercialization schedules.

Given the nature of biologics manufacturing, there is a risk of contamination in our manufacturing processes. Should we resume development of our product candidates, any contamination could materially adversely affect our ability to produce product candidates on schedule and could, therefore, harm our results of operations and cause reputational damage.

Some of the materials required in our manufacturing process are derived from biologic sources. Such materials are difficult to procure and may be subject to contamination or recall. A material shortage, contamination, recall or restriction on the use of biologically derived substances in the manufacture of our product candidates could adversely impact or disrupt the commercial manufacturing or the production of clinical material, which could materially and adversely affect our development timelines and our business, financial condition, results of operations and prospects.

Risks related to our business operations

Our gene therapy approach utilizes lentiviral vectors derived from viruses, which may be perceived as unsafe or may result in unforeseen adverse events. Negative public opinion and increased regulatory scrutiny of gene therapy and genetic research may damage public perception of our product candidates or adversely affect our ability to conduct our business or obtain regulatory approvals for our product candidates.

Gene therapy remains a novel technology, with only a limited number of gene therapy products approved to date. Public perception may be influenced by claims that gene therapy is unsafe, and gene therapy may not gain the acceptance of the public or the medical community. In particular, our success will depend upon physicians specializing in the treatment of those diseases that our product candidates target prescribing treatments that involve the use of our product candidates in lieu of, or in addition to, existing treatments they are already familiar with and for which greater clinical data may be available. More restrictive government regulations or negative public opinion would have a negative effect on our business or financial condition and may delay or impair the development and commercialization of our product candidates or demand for any products should we resume development of our product candidates. For example, earlier gene therapy trials led to several well-publicized adverse events, including cases of leukemia, myelodysplastic syndromes and deaths seen in other trials using other vectors. Adverse events in our clinical studies or discovered in

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long-term follow-up, even if not ultimately attributable to our product candidates (such as the many adverse events that typically arise from the conditioning process), or adverse events in other gene therapy trials, and the resulting publicity could result in a decline in our stock price, increased governmental regulation, unfavorable public perception and, should we resume development of our product candidates, potential regulatory delays in the testing or approval of our potential product candidates, stricter labeling requirements for those product candidates that are approved and a decrease in demand for any such product candidates.

Our future success depends on our ability to retain key employees, consultants and advisors and to attract, retain and motivate qualified personnel.

We are highly dependent on principal members of our executive team and key employees, the loss of whose services may adversely impact the achievement of our objectives. While we have entered into employment agreements with each of our executive officers, any of them could leave our employment at any time, as all of our employees are “at will” employees. Our former President and Chief Executive Officer, Geoff MacKay, resigned on May 1, 2023, and we have appointed our current Chief Financial Officer, Erik Ostrowski, as our interim President and Chief Executive Officer. In July 2023, in connection with the determination to halt further development of the Company’s programs and to conduct a comprehensive exploration of strategic alternatives, we paused our search for a permanent Chief Executive Officer. Accordingly, no assurance can be made as to when or if we will hire a permanent Chief Executive Officer. We do not maintain “key person” insurance policies on the lives of these individuals or the lives of any of our other employees. The loss of the services of one or more of our current executive or key employees might impede the achievement of our ongoing business commitments and strategic objectives.

Retaining other qualified employees, consultants and advisors for our business, including scientific and technical personnel, remains critical to our success. We implemented a reduction in force in January 2022 in connection with the deprioritization of our Fabry disease program, and through the first half of 2022 we continued to streamline employee headcount including senior management. In July 2023, in connection with the determination to halt further development of the Company’s programs and to conduct a comprehensive exploration of strategic alternatives, we implemented a reduction in force by approximately 50% across different areas. The Company’s remaining workforce was further reduced by 11 employees in a workforce reduction implemented effective as of October 31, 2023. Reductions in force, management changes and program reprioritizations can have an adverse impact on employee morale. While we believe our relations with our continuing employees to be good, there can be no assurance that we can avoid retention challenges for skilled personnel as the Company explores potential strategic alternatives. There is currently a shortage of skilled executives and other personnel in our industry, which is likely to continue. As a result, competition for skilled personnel, including in gene therapy research and vector manufacturing, is intense and the turnover rate can be high. We may not be able to retain personnel on acceptable terms given the competition among numerous pharmaceutical and biotechnology companies for individuals with similar skill sets. In addition, our ability to retain qualified personnel could be impacted by other factors, such as remote or hybrid working arrangements, which could impact employees’ productivity and morale. In addition, in recent months, the market price of our common stock has experienced significant downward pressure, resulting in “underwater” or “out-of-the-money” stock options for many of our employees, thereby limiting the desired retentive effect that our equity incentive program was intended to achieve. The inability to recruit, if necessary, or the loss of the services of any executive, key employee, skilled personnel, consultant or advisor may impede our business objectives. Furthermore, we may not realize, in full or in part, the anticipated benefits, savings and improvements in our cost structure from our workforce reductions and restructuring efforts due to unforeseen difficulties, delays or unexpected costs. If we are unable to realize the expected operational efficiencies and cost savings from the restructuring, our operating results and financial condition would be adversely affected. Our restructuring plan may also be disruptive to our operations, for example, our reductions in force could yield unanticipated consequences, such as increased difficulties in implementing our business strategy, including retention of our remaining employees, attrition beyond our reduction in force and employee litigation related to the reductions in force could be costly and prevent management from fully concentrating on the business.

Should we resume development of our product candidates, we may need to expand or streamline our operations and we may experience difficulties in managing any such changes, which could disrupt our operations.

Should we resume development of our product candidates, we may need to rapidly expand our full-time employee base and to hire more consultants and contractors. Our management may need to divert a disproportionate amount of its attention away from our day-to-day activities and devote a substantial amount of time to managing these growth activities. We may not be able to effectively manage the expansion of our operations, which may result in weaknesses in our infrastructure, operational mistakes, loss of business opportunities, loss of employees and reduced productivity among remaining employees. Our expected growth could require significant capital expenditures and may divert financial resources from other projects. If our management is unable to effectively manage our growth, our expenses may increase more than expected, our ability to generate and/or grow revenues could be reduced, and we may not be able to implement our business strategy. Our future financial performance and our ability to commercialize product candidates and compete effectively will depend, in part, on our ability to effectively manage any future growth.

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Conversely, headwinds in the overall economy and limited availability of suitable financing to meet our needs could constrain our ability to achieve our growth objectives, and could in turn lead to further reductions in force or scaling back of business operations, that could impact employee morale and adversely impact our ability to manage ongoing operations.

Should we resume development of our product candidates and we are unable to manage expected growth in the scale and complexity of our operations, our performance may suffer.

Should we resume development of our product candidates, we will need to expand our managerial, operational, financial and other systems and resources to manage our operations, resume our research and development activities and, in the longer term, build a commercial infrastructure to support commercialization of any of our product candidates that are approved for sale. Future growth would impose significant added responsibilities on members of management. It is likely that our management, finance, development personnel, systems and facilities currently in place may not be adequate to support this future growth. Our need to effectively manage our operations, growth and product candidates requires that we continue to develop more robust business processes and improve our systems and procedures in each of these areas and to attract and retain sufficient numbers of talented employees. We may be unable to successfully implement these tasks on a larger scale and, accordingly, may not achieve our research, development and growth goals.

Our employees, principal investigators, consultants and commercial partners may engage in misconduct or other improper activities, including non-compliance with regulatory standards and requirements and insider trading.

We are exposed to the risk of fraud or other misconduct by our employees, principal investigators, consultants and commercial partners. Misconduct by these parties could include intentional failures to comply with the regulations of the FDA or of other foreign regulatory authorities, provide accurate information to the FDA and other foreign regulatory authorities, comply with healthcare fraud and abuse laws and regulations in the United States and abroad, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and business conduct in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of healthcare professional interactions, drug pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Such misconduct could also involve the improper use of information obtained in the course of clinical studies, which could result in regulatory sanctions and cause serious harm to our reputation. We have adopted a code of conduct applicable to all of our employees, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant fines or other sanctions.

We are subject to certain U.S. and foreign anti-corruption, anti-money laundering, export control, sanctions, and other trade laws and regulations. We can face serious consequences for violations.

Among other matters, U.S. and foreign anti-corruption, anti-money laundering, export control, sanctions, and other trade laws and regulations, which are collectively referred to as Trade Laws, prohibit companies and their employees, agents, clinical research organizations, legal counsel, accountants, consultants, contractors, and other partners from authorizing, promising, offering, providing, soliciting, or receiving directly or indirectly, corrupt or improper payments or anything else of value to or from recipients in the public or private sector. Violations of Trade Laws can result in substantial criminal fines and civil penalties, imprisonment, the loss of trade privileges, debarment, tax reassessments, breach of contract and fraud litigation, reputational harm, and other consequences. We have direct or indirect interactions with officials and employees of government agencies or government-affiliated hospitals, universities, and other organizations. We also expect, should we resume development of our product candidates, that our non-U.S. activities would increase in time. Should we resume development of our product candidates, we would also expect to engage third parties for clinical trials and/or to obtain necessary permits, licenses, patent registrations, and other regulatory approvals and we can be held liable for the corrupt or other illegal activities of our personnel, agents, or partners, even if we do not explicitly authorize or have prior knowledge of such activities. The failure to comply with laws governing international business practices may result in substantial civil and criminal penalties and suspension or debarment from government contracting. The SEC also may suspend or bar issuers from trading securities on U.S. exchanges for violations of the United States Foreign Corrupt Practices Act’s accounting provisions.

We are subject, directly or indirectly, to federal and state healthcare fraud and abuse laws, false claims laws health information privacy and security laws, and other health care laws and regulations. If we are unable to comply, or have not fully complied, with such laws, we could face substantial penalties.

We are subject, and may be increasingly subject if we obtain FDA approval for any of our product candidates, to various federal and state fraud and abuse laws and regulations, including, without limitation, the federal Health Care Program Anti-Kickback Statute, the federal civil and criminal False Claims Act and Physician Payments Sunshine Act and regulations. See Section entitled “Business -

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Government Regulation - Other Healthcare Laws and Compliance Requirements” in our Annual Report on Form 10-K for the year ended December 31, 2022.

These laws will impact, among other things, our clinical trial programs, healthcare professional interactions, grant making activities, and our anticipated sales, marketing and medical educational programs. In addition, we may be subject to patient privacy laws by both the federal government and the states in which we conduct our business.

The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform. Federal and state enforcement bodies have recently increased their scrutiny of interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry. Ensuring business arrangements comply with applicable healthcare laws, as well as responding to possible investigations by government authorities, can be time- and resource-consuming and can divert a company’s attention from the business.

The failure to comply with any of these laws or regulatory requirements subjects entities to possible legal or regulatory action. Depending on the circumstances, failure to meet applicable regulatory requirements can result in significant civil, criminal and administrative penalties, damages, fines, disgorgement, individual imprisonment, exclusion from participation in federal and state funded healthcare programs (such as Medicare and Medicaid), contractual damages and the curtailment or restructuring of our operations, as well as additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws. Any action for violation of these laws, even if successfully defended, could cause a pharmaceutical manufacturer to incur significant legal expenses and divert management’s attention from the operation of the business. If any of the physicians or other healthcare providers or entities with whom we expect to do business is found not to be in compliance with applicable laws, that person or entity may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs. Prohibitions or restrictions on personnel, sales or withdrawal of future marketed products could materially affect business in an adverse way.

Efforts to ensure that our business arrangements will comply with applicable healthcare laws may involve substantial costs. It is possible that governmental and enforcement authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law interpreting applicable fraud and abuse or other healthcare laws and regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of civil, criminal and administrative penalties, damages, disgorgement, monetary fines, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, contractual damages, reputational harm, diminished profits and future earnings, and curtailment of our operations, any of which could adversely affect our ability to operate our business and our results of operations. In addition, the approval and commercialization of any of our candidates outside the United States will also likely subject us to foreign equivalents of the healthcare laws mentioned above, among other foreign laws.

Failure to comply with health and data protection laws and regulations could lead to government enforcement actions (which could include civil or criminal penalties), private litigation, and/or adverse publicity and could negatively affect our operating results and business.

We and any potential collaborators may be subject to federal, state, and foreign data protection laws and regulations (i.e., laws and regulations that address privacy and data security). In the United States, numerous federal and state laws and regulations, including federal health information privacy laws, state data breach notification laws, state health information privacy laws, and federal and state consumer protection laws (e.g., Section 5 of the Federal Trade Commission Act), that govern the collection, use, disclosure and protection of health-related and other personal information could apply to our operations or the operations of our collaborators. In addition, we may obtain health information from third parties (including research institutions from which we obtain clinical trial data) that are subject to privacy and security requirements under HIPAA, as amended by HITECH. Depending on the facts and circumstances, we could be subject to civil, criminal, and administrative penalties if we knowingly obtain, use, or disclose individually identifiable health information maintained by a HIPAA-covered entity in a manner that is not authorized or permitted by HIPAA.

Compliance with U.S. and international data protection laws and regulations could require us to take on more onerous obligations in our contracts, restrict our ability to collect, use and disclose data, or in some cases, impact our ability to operate in certain jurisdictions. Failure to comply with these laws and regulations could result in government enforcement actions (which could include civil, criminal and administrative penalties), private litigation, and/or adverse publicity and could negatively affect our operating results and business. Moreover, clinical trial patients, employees and other individuals about whom we or our potential collaborators obtain personal information, as well as the providers who share this information with us, may limit our ability to collect, use and disclose the information. Claims that we have violated individuals’ privacy rights, failed to comply with data protection laws, or breached our contractual obligations, even if we are not found liable, could be expensive and time-consuming to defend and could result in adverse publicity that could harm our business.

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European data collection is governed by restrictive regulations governing the use, processing and cross-border transfer of personal information.

Should we resume development of our product candidates, we would expect to conduct clinical trials in the European Economic Area, or EEA, and the United Kingdom, or UK, and as a result would be subject to additional privacy restrictions. The collection, use, disclosure, transfer or other processing of personal health data in the EU and the UK is governed by the provisions of the GDPR (references to the GDPR include both the “EU GDPR” and “UK GDPR” unless specified otherwise). The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal data, including requirements relating to processing health and other sensitive data, providing information to individuals regarding data processing activities, obtaining consent from individuals to whom the data processing relates, responding to additional data subject requests, imposing notification of personal data breaches to the competent national data protection authorities, implementing safeguards in connection with the security and confidentiality of the personal data, accountability requirements and taking certain measures when engaging third-party processors. The GDPR informs our obligations with respect to any clinical trials conducted in the EEA or the UK. Its definition of personal data includes coded data, requires changes to informed consent practices and detailed notices for clinical trial subjects and investigators. In addition, the GDPR imposes strict rules on the transfer of personal data out of the EEA or the UK, including to the United States (see below). The GDPR also permits data protection authorities to require destruction of improperly gathered or used personal data and/or impose substantial fines for violations of the GDPR, which can be up to four percent of global revenues or 20 million Euros (£ 17.5 million for the UK), whichever is greater, and confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. In addition, the GDPR provides that EEA member states or the UK may make their own further laws and regulations limiting the processing of personal data, including genetic, biometric, or health data.

The GDPR prohibits cross-border data transfers of personal data to countries outside the EEA or the UK that are not considered by the European Commission and UK government as providing “adequate” protection to personal data, or third countries, including the United States in certain circumstances, unless a valid GDPR transfer mechanism (for example, the European Commission approved Standard Contractual Clauses, or the SCCs, and the UK International Data Transfer Agreement/Addendum, or the UK IDTA) has been put in place. Where relying on the SCCs/UK IDTA for data transfers, we may also be required to carry out transfer impact assessments to assess whether the recipient is subject to local laws which allow public authority access to personal data. The international transfer obligations under the EEA and UK data protection regimes will require significant effort and cost, and may result in us needing to make strategic considerations around where EEA and UK personal data is located and which service providers we can utilize for the processing of EEA and UK personal data.

We have yet to adopt and implement comprehensive processes, systems and other relevant measures within our organization, and/or with our relevant collaborators, service providers, contractors or consultants, which are appropriate to address relevant requirements relating to international transfers of personal data from Europe, and to minimize the potential impacts and risks resulting from those requirements, across our organization. Failure to implement valid mechanisms for personal data transfers from Europe may result in our facing increased exposure to regulatory actions, substantial fines and injunctions against processing personal data from Europe. Inability to export personal data may also: restrict our activities outside Europe; limit our ability to collaborate with partners as well as other service providers, contractors and other companies outside of Europe; and/or require us to increase our processing capabilities within Europe at significant expense or otherwise cause us to change the geographical location or segregation of our relevant systems and operations – any or all of which could adversely affect our operations or financial results. Additionally, other countries outside of Europe have enacted or are considering enacting similar cross-border data transfer restrictions and laws requiring local data residency, which could increase the cost and complexity of delivering our services and operating our business. The type of challenges we face in Europe will likely also arise in other jurisdictions that adopt laws similar in construction to the GDPR or regulatory frameworks of equivalent complexity.

Although the UK is regarded as a third country under the EU GDPR, the EC has issued an adequacy decision recognizing the UK as providing adequate protection under the EU GDPR and, therefore, transfers of personal data originating in the EU to the UK remain unrestricted. Like the EU GDPR, the UK GDPR restricts personal data transfers outside the UK to countries not regarded by the UK as providing adequate protection. The UK government has confirmed that personal data transfers from the UK to the EU remain free flowing. The UK Government has also now introduced a Data Protection and Digital Information Bill, or the UK Bill, into the UK legislative process. The aim of the UK Bill is to reform the UK’s data protection regime following Brexit. If passed, the final version of the UK Bill may have the effect of further altering the similarities between the UK and EEA data protection regime and threaten the UK adequacy decision from the European Commission. The respective provisions and enforcement of the EU GDPR and UK GDPR may further diverge in the future and create additional regulatory challenges and uncertainties. This lack of clarity on future UK laws and regulations and their interaction with EU laws and regulations could add legal risk, complexity and cost to our handling of personal data and our privacy and data security compliance programs and could require us to implement different compliance measures for the UK and the EEA.

Given the breadth and depth of its obligations, complying with the GDPR’s requirements is rigorous and time intensive and requires significant resources and assessment of our technologies, systems and practices, as well as those of any third-party

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collaborators, service providers, contractors, or consultants that process or transfer personal data collected in the EEA or the UK. Compliance with the GDPR will be a rigorous and time-intensive process that may increase our cost of doing business and require us to change our business practices, and despite those efforts, there is a risk that we may be subject to fines and penalties, litigation, and reputational harm in connection with European activities.

We face potential product liability, and, if successful claims are brought against us, we may incur substantial liability and costs. If the use of our product candidates harms patients, or is perceived to harm patients even when such harm is unrelated to our product candidates, our regulatory approvals could be revoked or otherwise negatively impacted and we could be subject to costly and damaging product liability claims.

The use of our product candidates including in clinical studies and, should we resume the development of our product candidates, the future sale of any products for which we may obtain marketing approval, exposes us to the risk of product liability claims. Product liability claims might be brought against us by consumers, healthcare providers, pharmaceutical companies or others selling or otherwise coming into contact with our products. There is a risk that our product candidates may induce adverse events. If we cannot successfully defend against product liability claims, we could incur substantial liability and costs. In addition, regardless of merit or eventual outcome, product liability claims may result in:

•the impairment of our business reputation;

•the withdrawal of clinical study participants;

•costs due to related litigation;

•the distraction of management’s attention from our primary business;

•substantial monetary awards to patients or other claimants;

•the inability to commercialize our product candidates; and

•decreased demand for our product candidates, if approved for commercial sale.

We carry master product liability insurance of $5.0 million per occurrence and $5.0 million in the aggregate in the United States. For studies conducted in certain countries outside the United States, we maintain local admitted policies with varying limits. We believe our product liability insurance coverage is sufficient in light of our current clinical programs; however, we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to liability. If we resume development of our product candidates and thereafter obtain marketing approval for product candidates, we expect that we would expand our insurance coverage to include the sale of commercial products; however, we may be unable to obtain product liability insurance on commercially reasonable terms or in adequate amounts. On occasion, large judgments have been awarded in class action lawsuits based on drugs or medical treatments that had unanticipated adverse effects. A successful product liability claim or series of claims brought against us could cause our stock price to decline and, if judgments exceed our insurance coverage, could adversely affect our results of operations and business.

Patients with the diseases targeted by certain of our product candidates are often already in severe and advanced stages of disease and have both known and unknown significant pre-existing and potentially life- threatening health risks. During the course of treatment, patients may suffer adverse events, including death, for reasons that may be related to our product candidates. Such events could subject us to costly litigation, require us to pay substantial amounts of money to injured patients, delay, negatively impact or end our opportunity to receive or maintain regulatory approval to market our products, or require us to suspend or abandon our commercialization efforts. Even in a circumstance in which we do not believe that an adverse event is related to our products, the investigation into the circumstance may be time-consuming or inconclusive. These investigations may interrupt our sales efforts, delay our regulatory approval process in other countries, or impact and limit the type of regulatory approvals our product candidates receive or maintain. As a result of these factors, a product liability claim, even if successfully defended, could have a material adverse effect on our business, financial condition or results of operations.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations involve the use of hazardous and flammable materials, including chemicals and biological materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties. Furthermore, environmental laws and regulations are complex, change frequently and have tended to become more stringent. We cannot predict the impact of such changes and cannot be certain of our future

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compliance. In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials or other work-related injuries, this insurance may not provide adequate coverage against potential liabilities. In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions or liabilities, which could materially adversely affect our business, financial condition, results of operations and prospects.

We might not be able to utilize a significant portion of our net operating loss carryforwards and research and development tax credit carryforwards.

As of December 31, 2022 and 2021, we had federal and state net operating loss carryforwards of $340.4 million and $313.0 million, respectively, and federal research and development tax credit carryforwards of approximately $6.8 million and $6.2 million, respectively. If not utilized, the net operating loss carryforwards and research and development credits will generally expire at various dates through 2038 (other than federal net operating loss carryforwards generated in taxable years beginning after December 31, 2017, which are not subject to expiration and generally may not be carried back to prior taxable years except that net operating losses generated in 2018, 2019 and 2020 may be carried back five taxable years). These net operating loss and tax credit carryforwards could expire unused and be unavailable to offset future income tax liabilities. In addition, under Section 382 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a greater than 50 percentage point change, by value, in its equity ownership over a three-year period, the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change tax attributes to offset its post-change income may be limited. We may have experienced ownership changes in the past. We may also experience ownership changes in the future as a result of subsequent shifts in our stock ownership, some of which may be outside of our control. If an ownership change occurred or occurs and our ability to use our historical net operating loss and tax credit carryforwards is materially limited, or if our research and development carryforwards are adjusted, it would harm our future operating results by effectively increasing our future tax obligations. For taxable years beginning after December 31, 2020, deductions for federal net operating losses arising in taxable years beginning after December 31, 2017 may only offset 80% of taxable income.

Risks related to our intellectual property

Should we resume development of our product candidates, third-party claims of intellectual property infringement may prevent or delay our development and commercialization efforts.

Our commercial success depends in part on avoiding infringement of the patents and proprietary rights of third parties. There is a substantial amount of litigation, both within and outside the United States, involving patent and other intellectual property rights in the biotechnology and pharmaceutical industries, including patent infringement lawsuits, interferences, oppositions and inter parties reexamination proceedings before the U.S. Patent and Trademark Office, or USPTO, and corresponding foreign patent offices. Numerous U.S. and foreign issued patents and pending patent applications, which are owned by third parties, exist in the fields in which we are pursuing development candidates. As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our product candidates may be subject to claims of infringement of the patent rights of third parties.

Third parties may assert that we or our licensors are employing their proprietary technology without authorization. There may be third-party patents or patent applications with claims to materials, formulations, methods of manufacture or methods for treatment related to the use or manufacture of our product candidates. In particular, we are aware of issued patents in the United States that cover the lentiviral vectors used in the manufacture of our product candidates. While we believe that we have reasonable defenses against a claim of infringement, potentially including that certain of these patents are expected to expire prior to commercializing our product candidates, if approved, in the United States, there can be no assurance that we will prevail in any such action by the holder of these patents. In the event that the holder of these patents seeks to enforce its patent rights and our defenses against a claim of infringement are unsuccessful, we may not be able to commercialize our product candidates in the United States, if approved, without first obtaining a license to some or all of these patents, which may not be available on commercially reasonable terms or at all. In addition, the defense of any claim of infringement, even if successful, is time-consuming, expensive and diverts the attention of our management from our ongoing business operations.

Because patent applications can take many years to issue, there may be currently pending patent applications which may later result in issued patents that our product candidates may infringe or be alleged to infringe. In addition, third parties may obtain patents in the future and claim that use of our or our licensors’ technologies infringes upon these patents. If any third-party patents were held by a court of competent jurisdiction to cover the manufacturing process of any of our product candidates, any molecules formed

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during the manufacturing process or any final product itself, the holders of any such patents may be able to block our ability to commercialize such product candidate unless we obtained a license under the applicable patents, or until such patents expire.

Similarly, if any third-party patents were held by a court of competent jurisdiction to cover aspects of our formulations, processes for manufacture or methods of use, including combination therapy, the holders of any such patents may be able to block our ability to develop and commercialize the applicable product candidate unless we obtained a license or until such patent expires. In either case, such a license may not be available on commercially reasonable terms or at all.

Parties making claims against us may obtain injunctive or other equitable relief, which could effectively block our ability to further develop and commercialize one or more of our product candidates. Defense of these claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee resources from our business. In the event of a successful claim of infringement against us, we may have to pay substantial damages, including treble damages and attorneys’ fees for willful infringement, pay royalties, redesign our infringing products or obtain one or more licenses from third parties, which may be impossible or require substantial time and monetary expenditure. Even in the absence of a finding of infringement, we may choose to obtain a license, if such a license is available. A successful claim of patent or other intellectual property infringement against us could materially adversely affect our business, results of operations and financial condition.

Our rights to develop and commercialize our product candidates, should we resume development of our product candidates, are subject, in part, to the terms and conditions of licenses granted to us by others.

We depend upon the intellectual property rights granted to us under licenses from third parties that are important or necessary to the development of our technology and products, including technology related to our manufacturing process and our gene therapy product candidates. In particular, we have in-licensed certain intellectual property rights and know-how from the University Health Network, or UHN, (relevant to AVR-RD-01 and our Fabry program, which we deprioritized in January 2022) and affiliates of Lund University (relevant to AVR-RD-02 and our Gaucher type 1 and type 3 programs). On October 3, 2023, we provided UHN with a notice of termination with respect to the Fabry license agreement, specifying an effective termination date of January 4, 2024. In addition, we have in-licensed patents and patent applications from BioMarin Pharmaceutical Inc., or BioMarin, (relevant to AVR-RD-03 and our Pompe program) directed to compositions and methods related to the manufacture and use of AVR-RD-03. We also previously had in place in-licensed patent applications from The University of Manchester relevant to AVR-RD-05 and our Hunter program, which license agreement was terminated as of September 8, 2023. Any termination of our remaining licenses could result in the loss of significant rights and could harm or prevent our ability to commercialize our product candidates, should we resume development of such product candidates.

Each of our licenses with affiliates of Lund University and BioMarin are exclusive but are limited to particular fields, such as Gaucher disease type 1, or Pompe disease, and are subject to certain retained rights. Absent an amendment or additional agreement, we may not have the right to use intellectual property in-licensed for one of our programs for another program. In addition, licenses that we may enter into in the future may not provide exclusive rights to use such intellectual property and technology in all relevant fields of use and in all territories in which we may wish to develop or commercialize our technology and products in the future. As a result, we may not be able to prevent competitors from developing and commercializing competitive products in territories included in all of our licenses. Licenses to additional third-party technology that may be required for our development programs may not be available in the future or may not be available on commercially reasonable terms, or at all, which could have a material adverse effect on our business and financial condition.

In some circumstances, we may not have the right to control the preparation, filing and prosecution of patent applications, or to maintain the patents, covering technology that we license from third parties. For example, pursuant to each of our intellectual property licenses with BioMarin and the rights holders associated with Lund University, our licensors retain control of such activities. Therefore, we cannot be certain that these patents and applications will be prosecuted, maintained and enforced in a manner consistent with the best interests of our business. If our licensors fail to maintain such patents, or lose rights to those patents or patent applications, the rights we have licensed may be reduced or eliminated and our right to develop and commercialize any of our products that are the subject of such licensed rights could be adversely affected.

Our current license agreements impose, and we expect that future license agreements that we may enter into will impose, various obligations, including diligence and certain payment obligations. If we fail to satisfy our obligations, the licensor may have the right to terminate the agreement. Disputes may arise between us and any of our licensors regarding intellectual property subject to such agreements and other issues. Such disputes over intellectual property that we have licensed or the terms of our license agreements may prevent or impair our ability to maintain our current arrangements on acceptable terms, or at all, or may impair the value of the arrangement to us. Any such dispute could have a material adverse effect on our business. If we cannot maintain a necessary license agreement or if the agreement is terminated, we may be unable to successfully develop and commercialize the affected product candidates.

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If we are unable to obtain and maintain patent protection for our product candidates, or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize products similar or identical to ours, and our ability to successfully commercialize our product candidates may be adversely affected.

Should we resume development of our product candidates, our ability to compete effectively will depend, in part, on our ability to maintain the proprietary nature of our technology and manufacturing processes. We rely on manufacturing and other know-how, patents, trade secrets, trademarks, license agreements and contractual provisions to establish our intellectual property rights and protect our products. These legal means, however, afford only limited protection and may not adequately protect our rights. The failure to obtain, maintain, enforce or defend such intellectual property rights, for any reason, could allow third parties to make competing products or impact our ability to develop, manufacture and market our products, if approved, on a commercially viable basis, or at all, which could have a material adverse effect on our financial condition and results of operations.

In particular, we rely primarily on trade secrets, know-how and other unpatented technology, which are difficult to protect. Although we seek such protection in part by entering into confidentiality agreements with our vendors, employees, consultants and others who may have access to proprietary information, we cannot be certain that these agreements will not be breached, adequate remedies for any breach would be available or our trade secrets, know-how and other unpatented proprietary technology will not otherwise become known to or be independently developed by our competitors. Should we resume development of our product candidates and we are unsuccessful in protecting our intellectual property rights, sales of our products may suffer and our ability to generate revenue could be severely impacted.

Our licensors and we have sought, and we intend to continue to seek to protect our proprietary position by filing patent applications in the United States and, in at least some cases, one or more countries outside the United States related to product candidates that are important to our business. However, we cannot predict whether the patent applications we and our licensors are currently pursuing will issue as patents, whether the claims of any issued patents will provide us with a competitive advantage, or whether we will be able to successfully pursue patent applications in the future related to our product candidates, should we resume development of our product candidates. While we have in-licensed patents and patent applications relevant to AVR-RD-03, we currently have no owned or in-licensed patents or patent applications covering AVR-RD-01 or AVR-RD-02. Some of our product candidates are in-licensed from third parties. Accordingly, in some cases, the availability and scope of potential patent protection is limited based on prior decisions by our licensors or the inventors, such as decisions on when to file patent applications or whether to file patent applications at all.

Should we resume development of our product candidates, we may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting and defending patents on product candidates in all countries throughout the world would be prohibitively expensive, and our intellectual property rights in some countries outside the United States could be less extensive than those in the United States. Although our license agreements grant us worldwide rights, and our currently in-licensed U.S. patent rights have certain corresponding foreign patents or patent applications, there can be no assurance that we will obtain or maintain such corresponding patents or patent applications with respect to any future license agreements. In addition, the laws of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the United States even in jurisdictions where we and our licensors pursue patent protection. Consequently, we and our licensors may not be able to prevent third parties from practicing our inventions in all countries outside the United States, even in jurisdictions where we and our licensors pursue patent protection, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Competitors may use our technologies in jurisdictions where we and our licensors have not pursued and obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the United States. These products may compete with our product candidates and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to biotechnology products, which could make it difficult for us to stop the infringement of our patents or marketing of competing products in violation of our proprietary rights generally. Proceedings to enforce our patent rights, even if obtained, in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly and our patent applications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

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Issued patents covering our product candidates could be found invalid or unenforceable if challenged in court. We may not be able to protect our trade secrets in court.

If one of our licensing partners or we initiate legal proceedings against a third-party to enforce a patent covering one of our product candidates, should such a patent issue, the defendant could counterclaim that the patent covering our product candidate is invalid or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, including lack of novelty, obviousness, written description or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld information material to patentability from the USPTO, or made a misleading statement, during prosecution. Third parties also may raise similar claims before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination, post grant review, inter parties review and equivalent proceedings in foreign jurisdictions. Such proceedings could result in the revocation or cancellation of or amendment to our patents in such a way that they no longer cover our product candidates. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which the patent examiner and we or our licensing partners were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity or unenforceability, we could lose at least part, and perhaps all, of the patent protection on one or more of our product candidates. Such a loss of patent protection could have a material adverse impact on our business.

In addition to the protection afforded by patents, we rely on trade secret protection and confidentiality agreements to protect proprietary know-how that is not patentable or that we elect not to patent, processes for which patents are difficult to enforce and any other elements of our product candidate discovery and development processes that involve proprietary know-how, information or technology that is not covered by patents. However, trade secrets can be difficult to protect and some courts inside and outside the United States are less willing or unwilling to protect trade secrets. We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. We cannot guarantee that we have entered into such agreements with each party that may have or have had access to our trade secrets or proprietary technology and processes. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or be independently discovered by competitors.

We may be subject to claims asserting that our employees, consultants or advisors have wrongfully used or disclosed alleged trade secrets of their current or former employers or claims asserting ownership of what we regard as our own intellectual property.

Certain of our employees, consultants or advisors are currently, or were previously, employed at universities or other biotechnology or pharmaceutical companies, including our competitors or potential competitors. Although we try to ensure that our employees, consultants and advisors do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that these individuals or we have used or disclosed intellectual property, including trade secrets or other proprietary information, of any such individual’s current or former employer. Litigation may be necessary to defend against these claims. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to management. Our licensors may face similar risks, which could have an adverse impact on intellectual property that is licensed to us.

In addition, while it is our policy to require our employees and contractors who may be involved in the conception or development of intellectual property to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who, in fact, conceives or develops intellectual property that we regard as our own. The assignment of intellectual property rights may not be self-executing or the assignment agreements may be breached, and we may be forced to bring claims against third parties, or defend claims that they may bring against us, to determine the ownership of what we regard as our intellectual property.

We may be subject to claims challenging the inventorship or ownership of the patents and other intellectual property that we own or license.

We or our licensors may be subject to claims that former employees, collaborators or other third parties have an ownership interest in the patents and intellectual property that we own or license or that we may own or license in the future. While it is our policy to require our employees and contractors who may be involved in the development of intellectual property to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who in fact develops intellectual property that we regard as our own; our licensors may face similar obstacles. We could be subject to ownership disputes arising, for example, from conflicting obligations of consultants or others who are involved in developing our product candidates. Litigation may be necessary to defend against any claims challenging inventorship or ownership. If we or our licensors fail in defending any such claims, we may have to pay monetary damages and may lose valuable intellectual property rights,

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such as exclusive ownership of, or right to use, intellectual property, which could adversely impact our business, results of operations and financial condition.

Changes in U.S. patent law could diminish the value of patents in general, thereby impairing our ability to protect our product candidates.

Changes in either the patent laws or the interpretation of the patent laws in the United States could increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of issued patents. On September 16, 2011, the Leahy-Smith America Invents Act, or the Leahy-Smith Act, was signed into law. The Leahy-Smith Act includes several significant changes to U.S. patent law. These include provisions that affect the way patent applications are prosecuted and also may affect patent litigation. These also include provisions that switched the United States from a “first-to-invent” system to a “first-to-file” system, allow third-party submission of prior art to the USPTO during patent prosecution and set forth additional procedures to attack the validity of a patent by the USPTO administered post grant proceedings. Under a first-to-file system, assuming the other requirements for patentability are met, the first inventor to file a patent application generally will be entitled to the patent on an invention regardless of whether another inventor had made the invention earlier. The USPTO developed new regulations and procedures to govern administration of the Leahy-Smith Act, and many of the substantive changes to patent law associated with the Leahy-Smith Act, and in particular, the first to file provisions, only became effective on March 16, 2013. Accordingly, it is not clear what, if any, impact the Leahy-Smith Act will have on the operation of our business. However, the Leahy-Smith Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our patent applications and the enforcement or defense of our issued patents, all of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

The patent positions of companies engaged in the development and commercialization of biologics and pharmaceuticals are particularly uncertain. Two cases involving diagnostic method claims and “gene patents” were decided this year by the Supreme Court of the United States, or Supreme Court. On March 20, 2012, the Supreme Court issued a decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc., or Prometheus, a case involving patent claims directed to a process of measuring a metabolic product in a patient to optimize a drug dosage for the patient. According to the Supreme Court, the addition of well-understood, routine or conventional activity such as “administering” or “determining” steps was not enough to transform an otherwise patent-ineligible natural phenomenon into patent-eligible subject matter. On July 3, 2012, the USPTO issued a guidance memo to patent examiners indicating that process claims directed to a law of nature, a natural phenomenon or a naturally occurring relation or correlation that do not include additional elements or steps that integrate the natural principle into the claimed invention such that the natural principle is practically applied and the claim amounts to significantly more than the natural principle itself should be rejected as directed to not patent-eligible subject matter. On June 13, 2013, the Supreme Court issued its decision in Association for Molecular Pathology v. Myriad Genetics, Inc., or Myriad, a case involving patent claims held by Myriad Genetics, Inc. relating to the breast cancer susceptibility genes BRCA1 and BRCA2. Myriad held that an isolated segment of naturally occurring DNA, such as the DNA constituting the BRCA1 and BRCA2 genes, is not patent-eligible subject matter, but that complementary DNA, which is an artificial construct that may be created from RNA transcripts of genes, may be patent-eligible. On March 4, 2014, the USPTO issued a guidance memorandum to patent examiners entitled 2014 Procedure For Subject Matter Eligibility Analysis Of Claims Reciting Or Involving Laws Of Nature/Natural Principles, Natural Phenomena, And/Or Natural Products. These guidelines instruct USPTO examiners on the ramifications of the Prometheus and Myriad rulings and apply the Myriad ruling to natural products and principles including all naturally occurring nucleic acids.

Certain claims of our licensed patents and patent applications contain, and any future patents we may obtain may contain, claims that relate to specific recombinant DNA sequences that are naturally occurring at least in part and, therefore, could be the subject of future challenges made by third parties. In addition, the 2014 USPTO guidance could impact our ability to pursue similar patent claims in patent applications we may prosecute in the future.

We cannot assure you that our efforts to seek patent protection for our product candidates will not be negatively impacted by the decisions described above, rulings in other cases or changes in guidance or procedures issued by the USPTO. We cannot fully predict what impact the Supreme Court’s decisions in Prometheus and Myriad may have on the ability of life science companies to obtain or enforce patents relating to their products in the future. These decisions, the guidance issued by the USPTO and rulings in other cases or changes in USPTO guidance or procedures could have a material adverse effect on our existing patent rights and our ability to protect and enforce our intellectual property in the future.

Moreover, although the Supreme Court has held in Myriad that isolated segments of naturally occurring DNA are not patent-eligible subject matter, certain third parties could allege that activities that we may undertake infringe other gene-related patent claims, and we may deem it necessary to defend ourselves against these claims by asserting non-infringement and/or invalidity positions, or paying to obtain a license to these claims. In any of the foregoing or in other situations involving third-party intellectual property rights, if we are unsuccessful in defending against claims of patent infringement, we could be forced to pay damages or be subjected to an injunction that would prevent us from utilizing the patented subject matter. Such outcomes could harm our business, financial condition, results of operations or prospects.

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Should we resume development of our product candidates and we do not obtain patent term extension and data exclusivity for our product candidates, our business may be materially harmed.

Depending upon the timing, duration and specifics of any FDA marketing approval of our product candidates, one or more U.S. patents that we license or may own or license in the future, if any, may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, or Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent extension term of up to five years as compensation for patent term lost during the FDA regulatory review process. A patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, only one patent may be extended and only those claims covering the approved drug, a method for using it or a method for manufacturing it may be extended. A patent may only be extended once and only based on a single approved product. However, we may not be granted an extension because of, for example, failing to exercise due diligence during the testing phase or regulatory review process, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents or otherwise failing to satisfy applicable requirements. Moreover, the applicable time period or the scope of patent protection afforded could be less than we request. If we are unable to obtain patent term extension or the term of any such extension is less than we request, our competitors may obtain approval of competing products following our patent expiration, and our revenue could be reduced, possibly materially. In addition, we do not control the efforts of our licensors to obtain a patent term extension, and there can be no assurance that they will pursue or obtain such extensions to the patents that we license from them.

If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.

We have registered the marks “AVROBIO” and “plato” with the USPTO and in certain other countries, but we do not have trademarks or trademark applications with the USPTO for the marks “AVRO” or the AVROBIO logo. In the future, even if we apply for registration of these marks, there can be no assurance that such registration will be approved. Once registered, our trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks. We may not be able to protect our rights to these trademarks and trade names, which we need to build name recognition among potential partners or customers in our markets of interest. At times, competitors may adopt trade names or trademarks similar to ours, thereby impeding our ability to build brand identity and possibly leading to market confusion. In addition, there could be potential trade name or trademark infringement claims brought by owners of other registered trademarks or trademarks that incorporate variations of our registered or unregistered trademarks or trade names. Over the long term, if we are unable to establish name recognition based on our trademarks and trade names, then we may not be able to compete effectively and our business may be adversely affected. Our efforts to enforce or protect our proprietary rights related to trademarks, trade secrets, domain names, copyrights or other intellectual property may be ineffective and could result in substantial costs and diversion of resources and could adversely impact our financial condition or results of operations.

Intellectual property rights and regulatory exclusivity rights do not necessarily address all potential threats.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations, and may not adequately protect our business or permit us to maintain our competitive advantage, should we resume development of our product candidates. For example:

•others may be able to make gene therapy products that are similar to our product candidates but that are not covered by the claims of the patents that we license or may own or license in the future;

•we, our license partners or current or future collaborators, might not have been the first to make the inventions covered by the issued patents or pending patent applications that we license or may own or license in the future;

•we, our license partners or current or future collaborators, might not have been the first to file patent applications covering certain of our or their inventions;

•others may independently develop similar or alternative technologies or duplicate any of our technologies without infringing our owned or licensed intellectual property rights;

•it is possible that our pending licensed patent applications or those that we may own or license in the future will not lead to issued patents;

•issued patents that we hold rights to or may hold rights to in the future may be held invalid or unenforceable, including as a result of legal challenges by our competitors;

•one or more of our product candidates may never be protected by patents;

•our competitors might conduct research and development activities in countries where we do not have patent rights and then use the information learned from such activities to develop competitive products for sale in our major commercial markets;

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•we may not develop additional proprietary technologies that are patentable;

•the patents of others may have an adverse effect on our business; and

•we may choose not to file a patent application for certain trade secrets or know-how, and a third party may subsequently file a patent application or obtain a patent covering such intellectual property.

Should any of these events occur, they could significantly harm our business, financial condition, results of operations and prospects.

Risks related to ownership of our common stock

The market price of our common stock may be highly volatile, and you may not be able to resell your shares at or above the price at which you purchased our shares.

Our stock price is likely to be volatile. Since our initial public offering, or IPO, in June 2018, through November 2, 2023, the trading price of our common stock has ranged from $53.70 to $0.56. The stock market in general, and the market for biopharmaceutical companies in particular, has experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, you may not be able to sell your common stock at or above the price at which you purchased shares. The market price for our common stock may be influenced by many factors, including:

•the outcome of our exploration of strategic alternatives;

•adverse results or delays in preclinical studies or clinical trials;

•reports of adverse events in other gene therapy products or clinical studies of such products;

•an inability to obtain additional funding;

•failure by us to successfully develop and commercialize our product candidates;

•failure by us to maintain our existing strategic collaborations or enter into new collaborations;

•failure by us or our licensors and strategic partners to prosecute, maintain or enforce our intellectual property rights;

•changes in laws or regulations applicable to our product candidates;

•an inability to obtain adequate product supply for our product candidates or the inability to do so at acceptable prices;

•adverse regulatory decisions;

•the introduction of new products, services or technologies by our competitors;

•failure by us to meet or exceed financial projections we may provide to the public;

•failure by us to meet or exceed the financial projections of the investment community;

•the perception of the pharmaceutical industry by the public, legislatures, regulators and the investment community;

•announcements of significant acquisitions, strategic partnerships, joint ventures or capital commitments by us, our strategic partners or our competitors;

•disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to obtain patent protection for our technologies;

•additions or departures of key scientific or management personnel, or other skilled personnel;

•significant lawsuits, including patent or stockholder litigation;

•changes in the market valuations of similar companies;

•sales of our common stock by us or our stockholders in the future; and

•the trading volume of our common stock.

In addition, companies trading in the stock market in general, and Nasdaq in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

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We could be subject to securities class action litigation.

In the past, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us because pharmaceutical companies have experienced significant stock price volatility in recent years. If we face such litigation, it could result in substantial costs and a diversion of management’s attention and resources, which could harm our business.

An active trading market for our common stock may not be sustained.

Prior to our IPO in June 2018, there had been no public market for our common stock. Although our common stock is listed on Nasdaq, an active trading market for our shares may never be sustained. If an active market for our common stock is not sustained, it may be difficult for you to sell shares you purchased without depressing the market price for the shares, or at all.

An inactive trading market may also impair our ability to raise capital to continue to fund operations by selling additional shares and may impair our ability to acquire other companies or technologies by using our shares as consideration.

If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, our share price and trading volume could decline.

The trading market for our common stock will likely depend in part on the research and reports that securities or industry analysts publish about us or our business. We do not have any control over these analysts. Although we have obtained research coverage from certain analysts, there can be no assurance, including during such time period that we pursue potential strategic alternatives, that analysts will continue to cover us or provide favorable coverage. If one or more analysts downgrade our stock or change their opinion of our stock, our share price would likely decline. In addition, if one or more analysts cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which could cause our share price or trading volume to decline.

Concentration of ownership of our common stock among our existing executive officers, directors and principal stockholders may prevent new investors from influencing significant corporate decisions.

Based on shares outstanding as of November 2, 2023, our executive officers, directors, five percent stockholders and their affiliates beneficially owned approximately 42% of our voting stock. As a result, if these stockholders were to act together, they would be able to significantly influence all matters submitted to our stockholders for approval, as well as our management and affairs. For example, these stockholders, acting together, may be able to influence elections of directors, amendments of our organizational documents, or approval of any merger, sale of assets, or other major corporate transaction. This may prevent or discourage unsolicited acquisition proposals or offers for our common stock that you may believe are in your best interest as one of our stockholders. Some of these persons or entities may have interests different than yours. For example, because many of these stockholders purchased their shares at prices substantially below the current trading price of our stock and have held their shares for a longer period, they may be more interested in selling our Company to an acquirer than other investors or they may want us to pursue strategies that deviate from the interests of other stockholders. Additionally, from time to time, any of our non-affiliated stockholders may accumulate or acquire significant positions in our common stock and may similarly be able to influence our business or matters submitted to our stockholders for approval.

We are an “emerging growth company,” and the reduced disclosure requirements applicable to emerging growth companies may make our common stock less attractive to investors.

We are an “emerging growth company,” or EGC, as defined in the JOBS Act. We will remain an EGC until the earliest of: (i) the last day of the fiscal year in which we have total annual gross revenues of $1.235 billion or more; (ii) the last day of the fiscal year following the fifth anniversary of the date of the completion of our IPO; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the SEC, which means the first day of the year following the first year in which the market value of our common stock that is held by non-affiliates exceeds $700 million as of June 30 in any given year. For so long as we remain an EGC, we are permitted and intend to rely on exemptions from certain disclosure requirements that are applicable to other public companies that are not emerging growth companies. These exemptions include:

•not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, or Section 404;

•not being required to comply with any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation or a supplement to the auditor’s report providing additional information about the audit and the financial statements;

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•being permitted to provide only two years of audited financial statements, in addition to any required unaudited interim financial statements, with correspondingly reduced “Management’s discussion and analysis of financial condition and results of operations” disclosure;

•reduced disclosure obligations regarding executive compensation; and

•an exemption from the requirement to seek nonbinding advisory votes on executive compensation or golden parachute arrangements.

We may choose to take advantage of some, but not all, of the available exemptions. We have taken advantage of reduced reporting burdens in this Quarterly Report, or our Annual Report or 2023 Proxy Statement. In particular, we have not included in this Quarterly Report, and did not include in our 2023 Proxy Statement, all of the executive compensation information that would be required if we were not an EGC. We cannot predict whether investors will find our common stock less attractive if we rely on certain or all of these exemptions. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile.

In addition, the JOBS Act provides that an EGC may take advantage of an extended transition period for complying with new or revised accounting standards. This allows an EGC to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to avail ourselves of this exemption from new or revised accounting standards and, therefore, we will not be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies.

Even after we no longer qualify as an emerging growth company, we may still qualify as a “smaller reporting company” if the market value of our common stock held by non-affiliates is below $250 million (or $700 million if our annual revenue is less than $100 million) as of June 30 in any given year, which would allow us to take advantage of many of the same exemptions from disclosure requirements.

We expect to continue to incur increased costs as a result of operating as a public company, and our management is required to devote substantial time to new compliance initiatives.

As a public company, and particularly after we are no longer an EGC, we will incur significant legal, accounting and other expenses that we did not incur as a private company. In addition, the Sarbanes-Oxley Act of 2002 and rules subsequently implemented by the SEC and Nasdaq have imposed various requirements on public companies, including establishment and maintenance of effective disclosure and financial controls and corporate governance practices. Our management and other personnel will continue to devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations have increased our legal and financial compliance costs and will continue to make some activities more time-consuming and costly. For example, we expect that these rules and regulations may make it more difficult and increasingly more expensive for us to obtain and maintain director and officer liability insurance.

Pursuant to Section 404, we are required to furnish a report by our management on our internal control over financial reporting, and, once we are no longer an EGC or a “smaller reporting company,” we will be required to furnish an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. To achieve compliance with Section 404, we continue to be engaged in a process to document and evaluate our internal control over financial reporting, which is both costly and challenging. In this regard, we will need to continue to dedicate internal resources, potentially continue to engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting, continue steps to improve control processes as appropriate, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. Despite our efforts, there is a risk that we will not be able to conclude that our internal control over financial reporting is effective as required by Section 404. This could result in an adverse reaction in the financial markets due to a loss of confidence in the reliability of our financial statements.

If we fail to maintain an effective system of internal control over financial reporting, we may not be able to accurately report our financial results or prevent fraud. As a result, stockholders could lose confidence in our financial and other public reporting, which would harm our business and the trading price of our common stock.

Effective internal control over financial reporting is necessary for us to provide reliable financial reports and, together with adequate disclosure controls and procedures, are designed to prevent fraud. Any failure to implement required new or improved controls, or difficulties encountered in their implementation could cause us to fail to meet our reporting obligations. In addition, any testing by us conducted in connection with Section 404, or any subsequent testing by our independent registered public accounting firm, may reveal deficiencies in our internal control over financial reporting that are deemed to be material weaknesses or that may require prospective or retroactive changes to our financial statements, or may identify other areas for further attention or improvement. Inferior internal controls could also cause investors to lose confidence in our reported financial information, which could have a negative effect on the trading price of our stock.

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We are required to disclose changes made in our internal controls and procedures on a quarterly basis and our management is required to assess the effectiveness of these controls annually. However, for as long as we are an EGC or a “smaller reporting company,” our independent registered public accounting firm will not be required to attest to the effectiveness of our internal control over financial reporting pursuant to Section 404. We could be an EGC for up to five years following the completion of our IPO and will qualify as a “smaller reporting company” if the market value of our common stock held by non-affiliates is below $250 million (or $700 million if our annual revenue is less than $100 million) as of June 30 in any given year. An independent assessment of the effectiveness of our internal control over financial reporting could detect problems that our management’s assessment might not. Undetected material weaknesses in our internal control over financial reporting could lead to financial statement restatements and require us to incur the expense of remediation.

If we experience material weaknesses or deficiencies in the future, or otherwise fail to establish and maintain effective internal controls, we may be unable to produce timely and accurate financial statements, and we may conclude that our internal control over financial reporting is not effective, which could adversely impact our investors’ confidence and our stock price.

We expect to continue our efforts to improve our control processes, though there can be no assurance that our efforts will ultimately be successful or avoid potential material weaknesses, and we expect to continue incurring additional costs as a result of these efforts. If we are unable to successfully remediate any material weaknesses in our internal control over financial reporting, the accuracy and timing of our financial reporting may be adversely affected, we may be unable to maintain compliance with securities law requirements regarding timely filing of periodic reports in addition to applicable stock exchange listing requirements, investors may lose confidence in our financial reporting, and our stock price may decline as a result. We also could become subject to investigations by Nasdaq, the SEC or other regulatory authorities.

Our disclosure controls and procedures may not prevent or detect all errors or acts of fraud.

Our disclosure controls and procedures are designed to reasonably assure that information required to be disclosed by us in reports we file or submit under the Exchange Act is accumulated and communicated to management, recorded, processed, summarized and reported within the time periods specified in the rules and forms of the SEC. We believe that any disclosure controls and procedures or internal controls and procedures, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements or insufficient disclosures due to error or fraud may occur and not be detected.

We do not intend to pay dividends on our common stock, so any returns will be limited to the value of our stock.

We have never declared or paid any cash dividends on our common stock. We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. Any return to stockholders will therefore be limited to the appreciation of their stock.

Provisions in our amended and restated certificate of incorporation and by-laws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us or increase the cost of acquiring us, even if doing so would benefit our stockholders or remove our current management.

Our amended and restated certificate of incorporation, amended and restated by-laws and Delaware law contain provisions that may have the effect of delaying or preventing a change in control of us or changes in our management. Our amended and restated certificate of incorporation and by-laws, include provisions that:

•authorize “blank check” preferred stock, which could be issued by our board of directors without stockholder approval and may contain voting, liquidation, dividend and other rights superior to our common stock;

•create a classified board of directors whose members serve staggered three-year terms;

•specify that special meetings of our stockholders can be called only by our board of directors, the chairperson of our board of directors, our chief executive officer or our president;

•prohibit stockholder action by written consent;

•establish an advance notice procedure for stockholder approvals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to our board of directors;

•provide that our directors may be removed only for cause;

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•provide that vacancies on our board of directors may be filled only by a majority of directors then in office, even though less than a quorum;

•specify that no stockholder is permitted to cumulate votes at any election of directors;

•expressly authorize our board of directors to modify, alter or repeal our amended and restated by-laws; and

•require supermajority votes of the holders of our common stock to amend specified provisions of our amended and restated certificate of incorporation and amended and restated by-laws.

These provisions, alone or together, could delay or prevent hostile takeovers and changes in control or changes in our management.

In addition, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, which limits the ability of stockholders owning in excess of 15% of our outstanding voting stock to merge or combine with us.

Any provision of our amended and restated certificate of incorporation or amended and restated by-laws or Delaware law that has the effect of delaying or deterring a change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock, and could also affect the price that some investors are willing to pay for our common stock.

Our bylaws contain exclusive forum provisions, which may limit a stockholder’s ability to bring a claim in a judicial forum it finds favorable and may discourage lawsuits with respect to such claims.

Our amended and restated bylaws provide that, unless we consent in writing to an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for any state law claim for (1) any derivative action or proceeding brought on our behalf; (2) any action asserting a claim of breach of or based on a fiduciary duty owed by any of our current or former directors, officers or other employees to us or our stockholders; (3) any action asserting a claim against us or any of our current or former directors, officers, employees or stockholders arising pursuant to any provision of the Delaware General Corporation Law, our amended and restated certificate of incorporation or our amended and restated bylaws; or (4) any action asserting a claim governed by the internal affairs doctrine, or the Delaware Forum Provision. The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act or the Exchange Act. Our amended and restated bylaws further provide that, unless we consent in writing to an alternative forum, the United States District Court for the District of Massachusetts will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, or the Federal Forum Provision, as our principal executive offices are located in Cambridge, Massachusetts. In addition, our amended and restated bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the foregoing Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the U.S. federal securities laws and the rules and regulations thereunder.

We recognize that the Delaware Forum Provision and the Federal Forum Provision may impose additional litigation costs on stockholders in pursuing any such claims, particularly if the stockholders do not reside in or near the State of Delaware or the Commonwealth of Massachusetts. Additionally, these forum selection clauses in our amended and restated bylaws may limit our stockholders’ ability to bring a claim in a judicial forum that they find favorable for disputes with us or our directors, officers or employees, which may discourage such lawsuits against us and our directors, officers and employees even though an action, if successful, might benefit our stockholders. Section 22 of the Securities Act creates a concurrent jurisdiction for state and federal courts over all suits brought concerning a duty or liability created by the securities laws, rules and regulations thereunder. While the Delaware Supreme Court and other state courts have upheld the validity of federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court, there is uncertainty as to whether other courts will enforce our Federal Forum Provision. The Federal Forum Provision may also impose additional litigation costs on stockholders who assert the provision is unenforceable, and if the Federal Forum Provision is found to be unenforceable, we may incur additional costs with resolving such matters. The Court of Chancery of the State of Delaware and the United States District Court for the District of Massachusetts may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments may be more or less favorable to us than our stockholders.

Our failure to meet Nasdaq’s continued listing requirements could result in a delisting of our common stock.

If we fail to satisfy the continued listing requirements of Nasdaq, such as the corporate governance requirements or the requirement to maintain a minimum bid price of $1.00 per share pursuant to Nasdaq Listing Rule 5450(a)(1), or the Minimum Bid Price Requirement, Nasdaq may take steps to delist our common stock.

On October 4, 2022, we received a written notice from the staff, or the Staff, of Nasdaq’s Listing Qualifications Department, notifying us that, for the 30 consecutive business day period between August 22, 2022 through October 3, 2022, our common stock had not complied with the Minimum Bid Price Requirement. On February 23, 2023, we received a written notice from the Staff notifying us that for 10 consecutive business days, from February 8, 2023 to February 22, 2023, the closing bid price of our common

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stock was at $1.00 per share or greater, and accordingly, the Staff advised us that we had regained compliance with the Minimum Bid Price Requirement.

On May 11, 2023, we received a written notice from the Staff notifying us that, for the 30 consecutive business day period between March 29, 2023 through May 10, 2023, our common stock had not complied with the Minimum Bid Price Requirement. On June 12, 2023, we received a written notice from the Staff notifying us that for 14 consecutive business days, from May 22, 2023 to June 9, 2023, the closing bid price of our common stock was at $1.00 per share or greater, and accordingly, the Staff advised us that we had regained compliance with the Minimum Bid Price Requirement.

While we have regained compliance with the Minimum Bid Price Requirement as of the date of this Quarterly Report, we can provide no assurance that we will continue to remain in compliance with the Minimum Bid Price Requirement. If we are unable to maintain compliance with any of Nasdaq’s continued listing requirements in the future, we may be subject to delisting. At that time, we may appeal the Staff’s delisting determination to a Nasdaq Hearing Panel. There can be no assurance that, if we receive a delisting notice and appeal the delisting determination by the Staff to the Nasdaq Hearing Panel, such appeal would be successful.

Such a delisting would likely have a negative effect on the price of our common stock and would impair your ability to sell or purchase our common stock when you wish to do so. Any such delisting could also adversely impact our ability to raise additional capital or enter into strategic transactions. Additionally, if our common stock is not listed on, or becomes delisted from, Nasdaq for any reason, trading our common stock could be conducted only in the over-the-counter, or OTC, market or on an electronic bulletin board established for unlisted securities such as the OTC Bulletin Board, an inter-dealer automated quotation system for equity securities that is not a national securities exchange, and the liquidity and price of our common stock may be more limited than if we were quoted or listed on Nasdaq or another national securities exchange. In such circumstances, you may be unable to sell your common stock unless a market can be established or sustained.

 

General Risk Factors

Unfavorable global economic conditions could adversely affect our business, financial condition or results of operations.

Our results of operations could be adversely affected by general conditions in the global economy and in the global financial markets. For example, the COVID-19 pandemic has caused extreme volatility and disruptions in the capital and credit markets. In addition, Russia’s invasion of Ukraine and the evolving events in Israel and the Gaza Strip may lead to a prolonged, adverse impact on global economic, social and market conditions. A severe or prolonged economic downturn could result in a variety of risks to our business, including weakened demand for our product candidates and our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could also strain our suppliers, possibly resulting in supply disruption, or cause delays in payments for our services by third-party payors or our collaborators. For example, while we do not have any current operations in Ukraine, Russia, Israel or the Gaza Strip, we do not know the extent to which continuing and evolving conflicts in such regions could impact any of our current suppliers and their ability to provide us with supplies and services. Any of the foregoing could harm our business and we cannot anticipate all of the ways in which the current economic climate and financial market conditions could adversely impact our business, financial condition, results of operations and prospects.

We or the third parties upon whom we depend may be adversely affected by earthquakes or other natural disasters and our business continuity and disaster recovery plans may not adequately protect us from a serious disaster.

Earthquakes or other natural disasters could severely disrupt our operations, and have a material adverse effect on our business, results of operations, financial condition and prospects. If a natural disaster, power outage or other event occurred that prevented us from using all or a significant portion of our headquarters, that damaged critical infrastructure, such as the manufacturing facilities of our third-party contract manufacturers, or that otherwise disrupted operations, it may be difficult or, in certain cases, impossible for us to continue our business for a substantial period of time. The disaster recovery and business continuity plans we have in place currently are limited and are unlikely to prove adequate in the event of a serious disaster or similar event. We may incur substantial expenses as a result of the limited nature of our disaster recovery and business continuity plans, which, particularly when taken together with our lack of earthquake insurance, could have a material adverse effect on our business, financial condition, results of operations and prospects.

Our internal computer systems, or those of our collaborators or other contractors or consultants, may fail or suffer security breaches, which could result in a material disruption of our business operations or, if we resume development of our product candidates, our product development programs.

Despite our security measures, our internal computer systems and those of our current and any future collaborators and other contractors or consultants are vulnerable to damage from computer viruses, unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. For example, in 2017 we were subjected to a cyberattack by a third party, which led to the

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theft of a portion of our funds. We implemented remedial measures promptly following this breach and do not believe that this breach had a material adverse effect on our business. In addition, in February 2019, one of our vendors was subject to a cyberattack by a third party, which resulted in the payment by us of a fraudulent invoice. We have implemented remedial measures following this breach and do not believe that this breach had a material effect on our business. However, if any cyberattack or data breach were to occur in the future and cause interruptions in our or our collaborators’, contractors’ or consultants’ operations, it could result in a material disruption of our business operations or, if we resume development of our product candidates, our product development programs, whether due to a loss of our business data, trade secrets or other proprietary information or other similar disruptions. For example, the loss of clinical trial data from completed or future clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. should we resume development of our product candidates. To the extent that any disruption or security breach were to result in a loss of, or damage to, our data or applications, or inappropriate disclosure of confidential or proprietary information, we could incur liability, our competitive position could be harmed and the development and commercialization of our product candidates, should we resume their development, could be delayed.

Changes in tax law could adversely affect our business and financial condition.

The rules dealing with U.S. federal, state, and local income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect us or holders of our common stock. In recent years, many such changes have been made and changes are likely to continue to occur in the future. Future changes in tax laws could have a material adverse effect on our business, cash flow, financial condition or results of operations. We urge investors to consult with their legal and tax advisers regarding the implications of potential changes in tax laws on an investment in our common stock.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.

Not applicable.

Item 3. Defaults Upon Senior Securities.

Not applicable.

Item 4. Mine Safety Disclosures.

Not applicable.

Item 5. Other Information.

None.

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Item 6. Exhibits.

Exhibit Number	Description
3.1	Fourth Amended and Restated Certificate of Incorporation of the Registrant (filed as Exhibit 3.1 to our Current Report on Form 8-K filed on June 25, 2018 (File No. 001-38537) and incorporated herein by reference).
3.2	Certificate of Change of Registered Agent and/or Registered Office of the Registrant (filed as Exhibit 3.2 to our Quarterly Report on Form 10-Q filed on November 5, 2020 (File No. 001-38537) and incorporated herein by reference).
3.3	Amended and Restated By-laws of the Registrant (filed as Exhibit 3.2 to our Current Report on Form 8-K filed on June 25, 2018 (File No. 001-38537) and incorporated herein by reference).
31.1	Certification of Principal Executive Officer and Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.1*	Certification of Principal Executive Officer and Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS	Interactive Data Files pursuant to Rule 405 of Regulation S-T formatted in Inline Extensible Business Reporting Language (“Inline XBRL”).
101.SCH	Inline XBRL Taxonomy Extension Schema Document.
101.CAL	Inline XBRL Taxonomy Extension Calculation Linkbase Document.
101.DEF	Inline XBRL Taxonomy Extension Definition Linkbase Document.
101.LAB	Inline XBRL Taxonomy Extension Label Linkbase Document.
101.PRE	Inline XBRL Taxonomy Extension Presentation Linkbase Document.
104	Cover Page Interactive Data File (formatted as inline XBRL with applicable taxonomy extension information contained in Exhibits 101.*).

* Indicates the exhibit is being furnished, not filed, with this report.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	AVROBIO, INC.
Date: November 9, 2023	By:	/s/ Erik Ostrowski
		Erik Ostrowski
		President, Interim Chief Executive Officer, Chief Financial Officer and Treasurer (Principal Executive, Financial, and Accounting Officer)

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