sndx-10q_20200331.htm

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 (Section 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.:

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 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 May 6, 2020, there were 36,094,929 shares of the registrant’s Common Stock, par value $0.0001 per share, outstanding.

This Quarterly Report on Form 10-Q contains forward-looking statements and information within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act, which are subject to the “safe harbor” created by those sections. In some cases, you can identify forward-looking statements by terminology such as “may,” “will,” “should,” “could,” “expect,” “would,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “intend,” “project” or “continue,” or the negative or plural of these terms or other comparable terminology.

These statements are only current predictions and are subject to known and unknown risks, uncertainties and other factors that may cause our or our industry’s actual results, levels of activity, performance or achievements to be materially different from those anticipated by the forward-looking statements. We discuss many of these risks in this report in greater detail in the section titled “Risk Factors” and elsewhere in this report. You should not rely upon forward-looking statements as predictions of future events.

Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. Except as required by law, we are under no duty to update or revise any of the forward-looking statements, whether as a result of new information, future events or otherwise.

	March 31, 2020			December 31, 2019
ASSETS
Current assets:
Cash and cash equivalents	$	44,629		$	24,609
Restricted cash		115			—
Short-term investments		54,376			35,166
Prepaid expenses and other current assets		5,086			2,556
Total current assets		104,206			62,331
Property and equipment, net		259			281
Right-of-use asset, net		608			716
Other assets		82			197
Total assets	$	105,155		$	63,525
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	8,998		$	6,178
Accrued expenses and other current liabilities		7,795			10,195
Current portion of deferred revenue		1,517			1,517
Current portion of right-of-use liability		480			478
Total current liabilities		18,790			18,368
Long-term liabilities:
Deferred revenue, less current portion		12,754			13,133
Right-of-use liability, less current portion		306			419
Loan payable		19,792			—
Other long-term liabilities		4			5
Total long-term liabilities		32,856			13,557
Total liabilities		51,646			31,925
Commitments
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized; 0 shares outstanding at March 31, 2020 and December 31, 2019		—			—
Common stock, $0.0001 par value, 100,000,000 shares authorized; 30,240,838 and 27,140,484 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively		3			3
Additional paid-in capital		564,164			527,067
Accumulated other comprehensive income		48			—
Accumulated deficit		(510,706	)		(495,470	)
Total stockholders’ equity		53,509			31,600
Total liabilities and stockholders’ equity	$	105,155		$	63,525

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

	Three Months Ended March 31,
	2020			2019
Revenue:
License fees	$	379		$	379
Total revenues		379			379
Operating expenses:
Research and development		9,562			11,279
General and administrative		5,917			3,911
Total operating expenses		15,479			15,190
Loss from operations		(15,100	)		(14,811	)
Other (expense) income:
Interest expense		(449	)		—
Interest income		333			452
Other (expense) income		(20	)		57
Total other (expense) income		(136	)		509
Net loss	$	(15,236	)	$	(14,302	)
Other comprehensive income (loss):
Unrealized gain on marketable securities	$	48		$	33
Comprehensive loss	$	(15,188	)	$	(14,269	)
Net loss attributable to common stockholders	$	(19,142	)	$	(14,302	)
Net loss per share attributable to common stockholders—basic and diluted	$	(0.56	)	$	(0.53	)
Weighted-average number of common shares used to compute net loss per share attributable to common stockholders —basic and diluted		34,328,640			27,023,466

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

	Three Months Ended March 31,
	2020			2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$	(15,236	)	$	(14,302	)
Adjustments to reconcile net loss to net cash from operating activities:
Depreciation		23			(180	)
Amortization and accretion of investments		(110	)		—
Non-cash operating lease expense		108			—
Non-cash interest expense		62			—
Stock-based compensation		1,829			1,592
Changes in operating assets and liabilities:
Prepaid expenses and other assets		(2,530	)		(2,453	)
Accounts payable		2,820			2,908
Deferred revenue		(379	)		(379	)
Accrued expenses and other liabilities		(2,512	)		(4,017	)
Net cash used in operating activities		(15,925	)		(16,831	)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short-term investments		(34,938	)		(20,628	)
Proceeds from sales and maturities of short-term investments		15,885			33,380
Net cash (used in) provided by investing activities		(19,053	)		12,752
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock in at-the-market stock offering, net		—			830
Proceeds from direct stock offering, net		34,866			27,571
Proceeds from debt agreement, net		19,730			—
Proceeds from Employee Stock Purchase Plan		64			27
Proceeds from stock option exercises		338			—
Other		—			(2	)
Net cash provided by financing activities		54,998			28,426
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		20,020			24,347
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—beginning of period		24,724			33,985
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —end of period	$	44,744		$	58,332
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	$	126		$	—
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Issuance costs debt included in accounts payable and accrued expenses	$	82		$	171

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

Syndax Pharmaceuticals, Inc. (“we,” “us,” “our” or the “Company”) is a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies. We were incorporated in Delaware in 2005. We base our operations in Waltham, Massachusetts and we operate in one segment.

The Company has prepared the accompanying condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. The interim unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2020, and the results of operations and comprehensive loss for the three months ended March 31, 2020 and 2019, and cash flows for the three months ended March 31, 2020 and 2019. The results for the three months ended March 31, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020, 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, 2019, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K that was filed with the Securities and Exchange Commission (“SEC”) on March 5, 2020.

In 2011, the Company established a wholly owned subsidiary in the United Kingdom. There have been no activities for this entity to date. In 2014, the Company established a wholly owned U.S. subsidiary, Syndax Securities Corporation. The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

The Company’s significant accounting policies, which are disclosed in the audited consolidated financial statements for the year ended December 31, 2019 and the notes thereto are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 5, 2020. Since the date of that filing, there have been no material changes to the Company’s significant accounting policies except as noted below.

With the global spread of the ongoing COVID-19 pandemic in the first and second quarters of 2020, we have implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on our business. We anticipate that the COVID-19 pandemic could have an impact on the clinical development timelines for one or more of our clinical programs. The extent to which the COVID-19 pandemic impacts our business, our clinical development, manufacturing of clinical and commercial drug substance and drug product, and regulatory efforts, our corporate development objectives and the value of and market for our common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements in the U.S., Europe and other countries, and the effectiveness of actions taken globally to contain and treat the disease. The global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic could have a material adverse effect on our business, financial condition, results of operations and growth prospects.

In addition, we are subject to other challenges and risks specific to our business and our ability to execute on our strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry with development and commercial operations, including, without limitation, risks and uncertainties associated with: obtaining regulatory approval of our late-stage product candidate; delays or problems in the supply of our products, loss of single source suppliers or failure to comply with manufacturing regulations; identifying, acquiring or in-licensing additional products or product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; and the challenges of protecting and enhancing our intellectual property rights; complying with applicable regulatory requirements. In addition, to the extent the ongoing COVID-19 pandemic adversely affects our business and results of operations, it may also have the effect of heightening many of the other risks and uncertainties discussed above.

Debt issuance costs consist of payments made to secure commitments under certain debt financing arrangements. These amounts are recognized as interest expense over the period of the financing arrangement using the effective interest method. If the financing arrangement is canceled or forfeited, or if the utility of the arrangement to the Company is otherwise compromised, these costs are recognized as interest expense immediately. The Company’s consolidated financial statements present debt issuance costs related to a recognized debt liability as a direct reduction from the carrying amount of that debt liability.

The Company accounts for derivative financial instruments as either equity or liabilities in accordance with Accounting Standards Codification Topic 815, Derivatives and Hedging, based on the characteristics and provisions of each instrument. Embedded derivatives are required to be bifurcated from the host instruments and recorded at fair value if the derivatives are not clearly and closely related to the host instruments on issuance date. The Company did not have any material embedded derivatives that required bifurcation upon issuance or as of March 31, 2020.

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of costs and expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions.

We anticipate that the COVID-19 pandemic will have an impact on the clinical and pre-clinical development timelines for our clinical and pre-clinical programs. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the Company’s financial statements.

On December 19, 2014 (the “Effective Date”), the Company entered into a license agreement with Kyowa Kirin, Co., Ltd. (the KKC License Agreement), under which the Company granted KKC an exclusive license to develop and commercialize entinostat in Japan and Korea. Under the terms of the KKC License Agreement, the Company will be responsible for the manufacture and supply of the products during the development activities. In addition to the license and manufacturing obligations, the Company is obligated to provide KKC access to know-how and regulatory information the Company may develop over the life of the entinostat patent. Lastly, to the extent additional intellectual property is developed during the term of the agreement, KKC will receive the right to the intellectual property when and if available. KKC will conduct the development, regulatory approval filings, and commercialization activities of entinostat in Japan and Korea. KKC paid the Company $25.0 million upfront, which included a $7.5 million equity investment and a $17.5 million non-refundable cash payment. In addition, to the extent certain development and commercial milestones are achieved, KKC will be required to pay the Company up to $75.0 million in milestone payments over the term of the license agreement. The term of the agreement commenced on the Effective Date and, unless earlier terminated in accordance with the terms of the agreement, will continue on a country-by-country and product-by-product basis, until the later of: (i) the date all valid claims of the last effective patent among the Company’s patents expires or is abandoned, withheld, or is otherwise invalidated in such country; and (ii) 15 years from the date of the first commercial sale of a product in the Japan or Korea.

The equity purchase and the up-front payment of the license fee were accounted for separately. The Company allocated the amount of consideration equal to the fair value of the shares on the Effective Date, which resulted in $7.7 million of proceeds allocated to the equity purchase and the remaining consideration of $17.3 million allocated to the up-front license fee.

In October 2017, the Company announced that KKC enrolled the first Japanese patient into a local pivotal study of entinostat for the treatment of hormone receptor positive, human epidermal growth factor receptor 2 negative breast cancer. In accordance with the terms of the license agreement, KKC paid the Company a $5.0 million milestone payment which the Company received in December 2017.

The Company determined that the performance obligations associated with the KKC License Agreement include (i) the combined license, rights to access and use materials and data, and rights to additional intellectual property, and (ii) the clinical supply obligation. All other goods or services promised to KHK are immaterial in the context of the agreement. Under ASC 606, the

identification of the clinical supply obligation as a distinct performance obligation separate and apart from the license performance obligation resulted in a change in the performance period. The start of the performance period under ASC 606 was determined to be the contract inception date, December 19, 2014. The clinical supply was identified as a separate performance obligation under ASC 606 as (i) the Company is not providing a significant service of integration whereby the clinical supply and other promises are inputs into a combined output, (ii) the clinical supply does not significantly modify or customize the other promises nor is it significantly modified or customized by them, and (iii) the clinical supply is not highly interdependent or highly interrelated with the other promises in the agreement as KKC could choose not to purchase the clinical supply from the Company without significantly affecting the other promised goods or services. The Company further concluded that the clinical supply represented an immaterial performance obligation and therefore the entire $17.3 million allocated to the upfront payment was allocated to the combined license and will be recognized ratably over the performance period, representing contract inception though 2029. In 2017, KKC achieved a development milestone, and was required to pay the Company $5.0 million. The Company is recognizing the development milestone consideration over the performance period coinciding with the license to intellectual property. As the Company determined that its performance obligations associated with the KKC Agreement at contract inception were not distinct and represented a single performance obligation, and that the obligations for goods and services provided would be completed over the performance period of the agreement, any payments received by the Company from KKC, including the upfront payment and progress-dependent development and regulatory milestone payments, are recognized as revenue using a time-based proportional performance model over the contract term (December 2014 through 2029) of the collaboration, within license fees. To date no commercial milestone payments or royalties have been achieved.

Contract liabilities consisted of deferred revenue, as presented on the consolidated balance sheet, as of March 31, 2020. Deferred revenue related to the KHK License Agreement was $14.3 million as of March 31, 2020 and will be recognized over the remainder of the contract term.

Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company:

	Three Months Ended March 31,
	2020			2019
	(In thousands, except share and per share data)
Numerator—basic and diluted:
Net loss	$	(15,236	)	$	(14,302	)
Deemed dividend due to warrant reset		(3,906	)		—
Net loss attributable to common stockholders—basic and diluted	$	(19,142	)	$	(14,302	)
Net loss per share attributable to common stockholders—basic and diluted	$	(0.56	)	$	(0.53	)
Denominator—basic and diluted:
Weighted-average number of common shares used to compute net loss per share attributable to common stockholders—basic and diluted		34,328,640			27,023,466

The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares outstanding because such securities have an antidilutive impact due to losses reported (in common stock equivalent shares):

In June 2018, the Company signed an exchange agreement with an investor under which the investor exchanged 2,000,000 shares of common stock for 2,000,000 warrants. Further, as discussed in Note 13, in March 2019, the Company sold 2,095,039 shares of common stock as well as 2,500,000 pre-funded warrants and 4,595,039 Series 1 and Series 2 warrants. The pre-funded warrants are exercisable into shares of common stock for $0.0001 per share. In January 2020, the Company sold 3,036,719 shares of common stock as well as 1,338,287 pre-funded warrants. The warrants are exercisable into shares of common stock for $0.0001 per share. The shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing earnings per share.

In October 2017, the Company entered into a license agreement (the “Allergan License Agreement”) with Vitae Pharmaceuticals, Inc., a subsidiary of Allergan plc (“Allergan”), under which Allergan granted the Company an exclusive, sublicensable, worldwide license to a portfolio of preclinical, orally available, small molecule inhibitors of the interaction of Menin with the Mixed Lineage Leukemia (“MLL”) protein (the “Menin Assets”). The Company made a nonrefundable upfront payment of $5.0 million to Allergan in the fourth quarter of 2017. Additionally, subject to the achievement of certain milestone events, the Company may be required to pay Allergan up to $99.0 million in one-time development and regulatory milestone payments over the term of the Allergan License Agreement. In the event that the Company or any of its affiliates or sublicensees commercializes the Menin Assets, the Company will also be obligated to pay Allergan low single to low double-digit royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $70.0 million in potential one-time, sales-based milestone payments based on achievement of certain annual sales thresholds. Under certain circumstances, the Company may be required to share a percentage of non-royalty income from sublicensees, subject to certain deductions, with Allergan. The Company is solely responsible for the development and commercialization of the Menin Assets. Each party may terminate the Allergan License Agreement for the other party’s uncured material breach or insolvency; and the Company may terminate the Allergan License Agreement at will at any time upon advance written notice to Allergan. Allergan may terminate the Allergan License Agreement if the Company or any of its affiliates or sublicensees institutes a legal challenge to the validity, enforceability, or patentability of the licensed patent rights. Unless terminated earlier in accordance with its terms, the Allergan License Agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country. As of the date of the Allergan License Agreement, the asset acquired had no alternative future use nor had it reached a stage of technological feasibility. As the processes or activities that were acquired along with the license do not constitute a “business,” the transaction has been accounted for as an asset acquisition. In June 2019, the Company achieved certain development and regulatory milestones. As a result, in June 2019, the Company recorded $4.0 million as research and development expense. The $4.0 million payable has been recorded in accounts payable as of March 31, 2020.

In 2016, the Company entered into a license agreement (the “UCB License Agreement”) with UCB Biopharma Sprl (“UCB”), under which UCB granted to the Company a worldwide, sublicenseable, exclusive license to UCB6352, which the Company refers to as axatilimab, an investigational new drug (“IND”) ready anti-CSF-1R monoclonal antibody. The Company made a nonrefundable upfront payment of $5.0 million to UCB in 2016. Additionally, subject to the achievement of certain milestone events, the Company may be required to pay UCB up to $119.5 million in one-time development and regulatory milestone payments over the term of the UCB License Agreement. In the event that the Company or any of its affiliates or sublicensees commercializes axatilimab, the Company will also be obligated to pay UCB low double-digit royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $250.0 million in potential one-time, sales-based milestone payments based on achievement of certain annual sales thresholds. Under certain circumstances, the Company may be required to share a percentage of non-royalty income from sublicensees, subject to certain deductions, with UCB. The Company is solely responsible for the development and commercialization of axatilimab, except that UCB is performing a limited set of transitional chemistry, manufacturing and control tasks related to axatilimab. Each party may terminate the UCB License Agreement for the other party’s uncured material breach or insolvency; and the Company may terminate the UCB License Agreement at will at any time upon advance written notice to UCB. UCB may terminate the UCB License Agreement if the Company or any of its affiliates or sublicensees institutes a legal challenge to the validity, enforceability, or patentability of the licensed patent rights. Unless terminated earlier in accordance with its terms, the UCB License Agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country. As of the date of the UCB License Agreement, the asset acquired had no alternative future use nor had it reached a stage of technological feasibility. As the processes or activities that were acquired along with the license do not constitute a “business,” the transaction has been accounted for as an asset acquisition.

In March 2014, the Company entered into the ECOG Agreement with Eastern Cooperative Oncology Group, a contracting entity for the Eastern Cooperative Oncology Group—American College of Radiology Imaging Network Cancer Research Group (“ECOG-ACRIN”), that describes the parties’ obligations with respect to the NCI-sponsored pivotal Phase 3 clinical trial of entinostat. Under the terms of the ECOG Agreement, ECOG-ACRIN will perform this clinical trial in accordance with the clinical trial protocol and a mutually agreed scope of work. The Company is providing a fixed level of financial support for the clinical trial through an upfront payment of $0.7 million and a series of payments of up to $1.0 million each that are comprised of milestone payments through the completion of enrollment and time-based payments through the completion of patient monitoring post-enrollment. In addition, the Company is obligated to supply entinostat and placebo to ECOG-ACRIN for use in the clinical trial. From the second quarter of 2016 through the fourth quarter of 2018, we have entered into a number of amendments to the agreement to provide for additional study activities resulting in an increase of the contractual obligation of $5.1 million. We have agreed to provide this additional financial support to fund the additional activities required to ensure that the E2112 clinical trial will satisfy FDA registration requirements. As of March 31, 2020, the Company’s aggregate payment obligations under this agreement are approximately $24.6 million; and its remaining payment obligations are approximately $5.8 million, which are estimated to be paid over a period of approximately two years.

Data and inventions from the Phase 3 clinical trial are owned by ECOG-ACRIN. The Company has access to the data generated in the clinical trial, both directly from ECOG-ACRIN under the ECOG Agreement as well as from the NCI. Additionally, ECOG-ACRIN has granted the Company a non-exclusive royalty-free license to any inventions or discoveries that are derived from entinostat as a result of its use during the clinical trial, along with a first right to negotiate an exclusive license to any of these inventions or discoveries. Either party may terminate the ECOG Agreement in the event of an uncured material breach by the other party or if the U.S. Food and Drug Administration (“FDA”) or National Cancer Institute (“NCI”) withdraws the authorization to perform the clinical trial in the United States. The parties may jointly terminate the ECOG Agreement if the parties agree that safety-related issues support termination of the clinical trial. The Company records the appropriate clinical trial expenses in its financial statements by matching those expenses with the period in which the services and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial as measured by patient enrollment and the timing of various aspects of the clinical trial. The Company determines accrual estimates through financial models, taking into account discussion with applicable personnel and ECOG-ACRIN as to the progress or state of consummation of the clinical trial or the services completed.

In March 2007, the Company entered into a license agreement (the “Bayer Agreement”) with Bayer Schering Pharma AG (“Bayer”) for a worldwide, exclusive license to develop and commercialize entinostat and any other products containing the same active ingredient. Under the terms of the Bayer Agreement, the Company paid a nonrefundable upfront license fee of $2.0 million and is responsible for the development and marketing of entinostat. The Company recorded the $2.0 million license fee as research and development expense during the year ended December 31, 2007, as it had no alternative future use. The Company will pay Bayer royalties on a sliding scale based on net sales, if any, and make future milestone payments to Bayer of up to $150.0 million in the event that certain specified development and regulatory goals and sales levels are achieved.

The carrying amounts of cash and cash equivalents, restricted cash, accounts payable, and accrued expenses approximated their estimated fair values due to the short-term nature of these financial instruments. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value are performed in a manner to maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value, which are the following:

During the periods presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy for any of periods presented.

A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows:

	Fair Value Measurements Using
			Quoted
			Prices		Significant
			(unadjusted)		Other		Significant
	Total		in Active		Observable		Unobservable
	Carrying		Markets		Inputs		Inputs
	Value		(Level 1)		(Level 2)		(Level 3)
	(In thousands)
March 31, 2020
Assets:
Cash and cash equivalents	$	44,629	$	44,629	$	—	$	—
Short-term investments		54,376		—		54,376		—
Total assets	$	99,005	$	44,629	$	54,376	$	—
December 31, 2019
Assets:
Cash and cash equivalents	$	24,609	$	23,439	$	1,170	$	—
Short-term investments		35,166		—		35,166		—
Total assets	$	59,775	$	23,439	$	36,336	$	—

Cash and cash equivalents of $44.6 million and $23.4 million as of March 31, 2020 and December 31, 2019, respectively, consisted of overnight investments and money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. Cash equivalents of $1.2 million as of December 31, 2019, consisted of highly rated corporate bonds and commercial paper and are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined through the use of models or other valuation methodologies.

Short-term investments of $54.4 million and $35.2 million as of March 31, 2020 and December 31, 2019, respectively, consisted of commercial paper, highly rated corporate bonds and asset backed securities and are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined through the use of models or other valuation methodologies.

The short-term investments are classified as available-for-sale securities. As of March 31, 2020, the remaining contractual maturities of the available-for-sale securities were less than one year, and the balance in the Company’s accumulated other comprehensive income was comprised solely of activity related to the Company’s available-for-sale securities. There were no realized gains or losses recognized on the sale or maturity of available-for-sale securities during the three months ended March 31, 2020 and 2019. As a result, the Company did not reclassify any amounts out of accumulated other comprehensive income for the same periods. The Company has a limited number of available-for-sale securities in insignificant loss positions as of March 31, 2020, which the Company does not intend to sell and has concluded it will not be required to sell before recovery of the amortized cost for the investment at maturity. The following table summarizes the available-for-sale securities:

	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses			Fair Value
	(In thousands)
March 31, 2020
Commercial paper	$	36,987	$	85	$	—		$	37,072
Corporate bonds		15,041		1		(38	)		15,004
Asset-backed securities		2,300		—		—			2,300
	$	54,328	$	86	$	(38	)	$	54,376
December 31, 2019
Commercial paper	$	15,675	$	5	$	—		$	15,680
Corporate bonds		18,361		—		(5	)		18,356
Asset-backed securities		2,300		—		—			2,300
	$	36,336	$	5	$	(5	)	$	36,336

	March 31, 2020		December 31, 2019
	(In thousands)
Short-term deposits	$	2,343	$	1,297
Prepaid clinical supplies		152		166
Interest receivable on investments		167		116
Reimbursable costs		324		416
Prepaid insurance		1,693		214
Other		407		347
Total prepaid expenses and other current assets	$	5,086	$	2,556

In January 2020, the number of shares of common stock available for issuance under the 2015 Omnibus Incentive Plan (“2015 Plan”), was increased by 1,085,619 shares due to the automatic annual provision to increase shares available under the 2015 Plan. As of March 31, 2020, the total number of shares of common stock available for issuance under the 2015 Plan was 765,348. The Company recognized stock-based compensation expense related to the issuance of stock option awards to employees and non-

employees and related to the 2015 Employee Stock Purchase Plan (“ESPP”) in the condensed consolidated statements of comprehensive loss as follows:

Compensation expense by type of award in the three months ended March 31, 2020 and 2019 was as follows:

During the three months ended March 31, 2020, the Company granted 1,121,825 stock options to certain executives and employees having service-based vesting conditions. The grant date fair value of the options granted in the three months ended March 31, 2020, was $7.3 million, or $6.52 per share on a weighted-average basis and will be recognized as compensation expense over the requisite service period of three to four years.

In 2019, the Company granted 583,000 stock options to certain employees to purchase shares of common stock that contain certain performance-based vesting criteria, primarily related to the achievement of certain clinical and regulatory development milestones related to product candidates. Recognition of stock-based compensation expense associated with these performance-based stock options commences when the performance condition is considered probable of achievement, using management’s best estimates, which consider the inherent risk and uncertainty regarding the future outcomes of the milestones.

The achievement of one of the performance milestones was considered to be probable and the Company recorded approximately $50,000 of stock compensation expense associated with these awards for the three months ended March 31, 2020. One performance milestone was not achieved by December 31, 2019, and therefore 194,338 stock options were cancelled on January 1, 2020. For the remaining award containing performance-based vesting criteria, the achievement of the milestone was considered not probable, nor met, and therefore no expense has been recognized related to this award for the three months ended March 31, 2020.

During the three months ended March 31, 2020, 51,034 options were exercised for cash proceeds of $338,000. No options were exercised in the three months ended March 31, 2019.

As of March 31, 2020, there was $15.6 million of unrecognized compensation cost related to employee and non-employee unvested stock options granted under the 2015 and 2007 Plans, which is expected to be recognized over a weighted-average remaining service period of 2.7 years. Stock compensation costs have not been capitalized by the Company.

During the three months ended March 31, 2020, the Company granted 15,000 shares of the Company’s restricted stock units. The shares are scheduled to vest in equal annual tranches over a four-year period on the anniversary date of the related grant. The fair value of these shares totaled $142,000 at the grant date, representing a weighted-average grant date fair value per share of $9.47.

In January 2020, the number of shares of common stock available for issuance under the ESPP, was increased by 271,404 shares as a result of the automatic increase provision of the ESPP. As of March 31, 2020, the total number of shares of common stock available for issuance under the ESPP was 1,115,797. The Company issued 12,601 shares during the first three months of 2020.

The ESPP is considered a compensatory plan with the related compensation cost expensed over the six-month offering period starting on February 1 and on August 1. The compensation expense related to the ESPP for the three months ended March 31, 2020,

was approximately $36,000. The compensation expense related to the ESPP recorded in the three months ended March 31, 2019, was approximately $33,000.

In February 2020, the Company entered into a loan and security agreement (the “Loan Agreement”) with Hercules Capital, Inc. (“Hercules”), which provided for aggregate maximum borrowings of up to $30.0 million, consisting of (i) a term loan of up to $20.0 million, which was funded on February 7, 2020 (the “Initial Advance”), and (ii) subject to Hercules’ investment committee approval, an additional term loan of up to $10.0 million, available for borrowing from February 7, 2020 to December 15, 2020 (the “Tranche 2 Advance”). Borrowings under the Loan Agreement bear interest at an annual rate equal to the greater of (i) 9.85% or (ii) 5.10% plus the Wall Street Journal prime rate. As of March 31, 2020, the Company’s interest rate under the Loan Agreement was 9.85%.

Borrowings under the Loan Agreement are repayable in monthly interest-only payments through October 1, 2021, or April 1, 2022 if the Phase 3 clinical trial of entinostat (E2112) in patients with advanced hormone receptor positive, human epidermal growth factor receptor 2 negative, breast cancer has achieved the primary efficacy endpoint sufficient to file an NDA as the next step in clinical development (“Performance Milestone”). After the interest-only payment period, borrowings under the Loan Agreement are repayable in equal monthly payments of principal and accrued interest until the maturity date of the loan, which is either (i) September 1, 2023, or (ii) March 1, 2024 upon achievement of the Performance Milestone (the “Maturity Date”). At the Company’s option, the Company may prepay all, but not less than all, of the outstanding borrowings, subject to a prepayment premium equal to (i) 2.0% of the principal amount outstanding if the prepayment occurs during the first year following the applicable loan being funded, (ii) 1.5% of the principal amount outstanding if the prepayment occurs during the second year following the applicable loan being funded, and (iii) 1.0% of the principal amount outstanding at any time thereafter but prior to the Maturity Date. In addition, the Company paid a $100,000 facility charge upon closing, which is being expensed over the term of the debt, and will pay a $50,000 facility charge in connection with the Tranche 2 Advance. The Loan Agreement also provides for a final payment, payable upon maturity or the repayment in full of all obligations under the agreement, of up to 4.99% of the aggregate principal amount of the Term Loan Advances (as defined in the Loan Agreement). The final payment will be accrued over the term of the debt.

Borrowings under the Loan Agreement are collateralized by substantially all of the Company’s and its subsidiaries personal property and other assets, other than its intellectual property. The Loan Agreement includes a minimum cash covenant of $12.5 million that applies commencing on October 1, 2020, subject to reduction upon satisfaction of certain conditions as set forth in the Loan Agreement. In addition, the Loan Agreement includes customary affirmative and restrictive covenants and representations and warranties, including a covenant against the occurrence of a “change in control,” financial reporting obligations, and certain limitations on indebtedness, liens (including a negative pledge on intellectual property and other assets), investments, distributions (including dividends), collateral, investments, distributions, transfers, mergers or acquisitions, taxes, corporate changes, and deposit accounts. The Loan Agreement also includes customary events of default, including payment defaults, breaches of covenants following any applicable cure period, the occurrence of certain events that could reasonably be expected to have a “material adverse effect” as set forth in the Loan Agreement, cross acceleration to third-party indebtedness and certain events relating to bankruptcy or insolvency. Upon the occurrence of an event of default, a default interest rate of an additional 5.0% may be applied to the outstanding principal balance, and Hercules may declare all outstanding obligations immediately due and payable and take such other actions as set forth in the Loan Agreement.

In connection with the Loan Agreement, the Company was required to enter into separate deposit account control agreements with the lender in order to perfect the lender’s security interest in the cash collateral in the Company’s operating accounts. In the event of a default under the Loan Agreement, the lender would have the right to take control of the operating accounts and restrict the Company’s access to the operating accounts and the funds therein.

During the quarter ended March 31, 2020, the Company recognized $0.4 million of interest expense related to the Initial Advance pursuant to the Loan Agreement.

As of March 31, 2020, the Company’s maturities of principal obligations under its long-term debt are as follows:

The following table presents the changes in stockholders’ equity for the three months ended March 31, 2020:

(In thousands, except share data)	Common Stock $0.0001 Par Value				Additional Paid-In Capital			Accumulated Other Comprehensive Income / (Loss)		Accumulated Deficit			Total Stockholders’ Equity
	Shares		Amount
Balance as of December 31, 2019		27,140,484	$	3	$	527,067		$	—	$	(495,470	)	$	31,600
Stock purchase under ESPP		12,601		—		—			—		—			—
Stock-based compensation expense		—		—		1,829			—		—			1,829
Proceeds from direct offering, net of $93 offering expenses		3,036,719		—		24,201			—		—			24,201
Proceeds from pre-funded common stock warrant from direct offering, net of $41 offering expenses		—		—		10,665			—		—			10,665
Deemed dividend from repricing Series 1 and 2 warrants		—		—		3,906			—		—			3,906
Repricing Series 1 and 2 warrants		—		—		(3,906	)		—		—			(3,906	)
Proceeds from exercise of stock options		51,034		—		338			—		—			338
Unrealized gains on short-term investments		—		—					48		—			48
Employee withholdings ESPP		—		—		64			—		—			64
Net loss		—		—		—			—		(15,236	)		(15,236	)
Balance as of March 31, 2020		30,240,838	$	3	$	564,164		$	48	$	(510,706	)	$	53,509

The following table presents the changes in stockholders’ equity for the three months ended March 31, 2019:

(In thousands, except share data)	Common Stock $0.0001 Par Value				Additional Paid-In Capital		Accumulated Other Comprehensive Income / (Loss)			Accumulated Deficit			Total Stockholders’ Equity
	Shares		Amount
Balance as of December 31, 2018		24,835,951	$	2	$	492,493	$	(25	)	$	(439,423	)	$	53,047
Stock purchase under ESPP		23,970		—		—		—			—			—
Proceeds from 'at-the-market' offering, net of $34 offering expenses		140,819		—		830		—			—			830
Stock-based compensation expense		—		—		1,592		—			—			1,592
Proceeds from direct offering, net of $1,571 in common stock warrants, $78 offering expenses		2,095,039		1		10,921		—			—			10,922
Proceeds from pre-funded common stock warrant from direct offering, net of $1,875 in common stock warrants, $93 offering expenses		—		—		13,032		—			—			13,032
Issuance of common stock warrant with direct offering		—		—		3,446		—			—			3,446
Unrealized gains on short-term investments		—		—		—		33			—			33
Employee withholdings ESPP		—		—		26		—			—			26
Net loss		—		—		—		—			(14,302	)		(14,302	)
Balance as of March 31, 2019		27,095,779	$	3	$	522,340	$	8		$	(453,725	)	$	68,626

In April 2017, the Company entered into a sales agreement with Cowen and Company, LLC (“Cowen”) under which the Company may issue and sell shares of our common stock having aggregate sales proceeds of up to $50.0 million from time to time through Cowen, acting as agent, in a series of one or more at-the-market (the “2017 ATM Program”) equity offerings. Cowen is not required to sell any specific amount, but acts as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. The Company pays Cowen up to 3% of the gross proceeds from any common stock sold through this sales agreement. In the first quarter of 2019, the Company sold 140,819 shares of common stock under the 2017 ATM Program for net proceeds of $0.8 million.

In August 2019, the Company entered into a new sales agreement with Cowen under which the Company may issue and sell shares of its common stock having aggregate sales proceeds of up to $50.0 million from time to time through Cowen, acting as agent, in a series of one or more ATM equity offerings (the “2019 ATM Program”). Cowen is not required to sell any specific amount, but acts as the Company’s sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. Shares sold pursuant to the sales agreement will be sold pursuant to a shelf registration statement on Form S-3 (Registration No. 333-233564), which was declared effective on September 10, 2019. The Company’s common stock will be sold at prevailing market prices at the time of the sale; and as a result, prices may vary. In the first quarter of 2020, and through May 6, 2020, the Company sold no additional shares of common stock under the ATM program.

In March 2019, the Company issued 2,095,039 shares of its common stock and pre-funded warrants to purchase 2,500,000 shares of common stock to certain investors in a registered direct offering. The pre-funded warrants are exercisable immediately upon issuance at an exercise price of $0.0001 per share and have a term of 20 years. The Company sold the shares of common stock and pre-funded warrants together with two series of warrants, Series 1 Warrants and Series 2 Warrants, to purchase an aggregate of 4,595,039 shares of the Company’s common stock (collectively, the “Series Warrants”). The offering price for the securities was $6.00 per share (or $5.9999 for each Pre-Funded Warrant). The aggregate gross proceeds to the Company from this offering were $27.6 million, excluding any proceeds the Company may receive upon exercise of the pre-funded warrants and Series Warrants and offering costs of $0.2 million. No underwriter or placement agent participated in the offering.

The Series Warrants are immediately exercisable. Each Series 1 Warrant has an initial exercise price of $12.00 per share of common stock and each Series 2 Warrant has an initial exercise price of $18.00 per share of common stock, in each case subject to certain adjustments. The Series Warrants expire on the earlier of (i) 90 days following the Company’s confirmation to holders of the Company’s release of positive data confirming the achievement of the specified primary endpoint of overall survival benefit in the E2112 clinical trial in breast cancer patients, or (ii) December 31, 2020.

If, prior to the expiration date of the Series Warrant, the Company sells additional capital stock or derivative securities convertible into or exercisable for capital stock, as defined, in one or more related transactions primarily for the purpose of raising capital at a Weighted-Average Price (as described below) below $12.00 per share, then the initial exercise price of the Series Warrants will be automatically reset upon exercise to an exercise price (the “Adjusted Exercise Price”) that is the midpoint between the initial exercise price and the lowest Weighted-Average Price per share at which the Company sells capital stock or derivative securities convertible into or exercisable for capital stock in a subsequent offering prior to the exercise date; provided, however, that the Adjusted Exercise Price will not be reduced below $6.00 per share. The Weighted-Average Price shall be calculated as the weighted-average common stock equivalent price of the equity securities sold in such transaction(s) (excluding any derivative securities with an exercise or conversion price that is above the closing sale price as of the time of pricing such offering(s)). In no event will the exercise price for the Series Warrants be adjusted more than once pursuant to this adjustment mechanism.

The Pre-Funded Warrants and the Series Warrants may not be exercised by the holder to the extent that the holder, together with its affiliates, would beneficially own, after such exercise more than 9.99% of the shares of the Company’s common stock then outstanding (subject to the right of the holder to increase or decrease such beneficial ownership limitation upon notice to the Company, provided that such limitation cannot exceed 19.99%) and provided that any increase in the beneficial ownership limitation shall not be effective until 61 days after such notice is delivered.

The Series Warrants were classified as a component of permanent equity and were recorded at the issuance date using a relative fair value allocation method. The Series Warrants are equity classified because they are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of shares of common stock upon exercise. In addition, such warrants do not provide any guarantee of value or return. The Company valued the Series Warrants at issuance in March 2019 using the Black Scholes option pricing model and determined the fair value of the 4,595,039 Series Warrants at $3.4 million. The key inputs to the valuation model included the weighted average volatility of 89.1% and the weighted-average expected term of 1.4 years.

In January 2020, the Company sold 3,036,719 shares of common stock, and pre-funded warrants to purchase 1,338,287 shares of common stock. The offering price for the securities was $8.00 per share of common stock or $7.9999 for each pre-funded warrant. As a result of this offering, the exercise price of Series 1 Warrants and Series 2 Warrants outstanding reset from $12.00 per share to $10.00 per share and from $18.00 per share to $13.00, respectively. The Company recorded $3.9 million as a deemed dividend which represents the value transferred to the warrant holders due to the Series Warrant adjustment mechanism being triggered. The deemed dividend was recorded as both an increase and a decrease in Additional Paid-in-Capital and reduced net income available to common stockholders by the same amount. The key inputs to the valuation model included the weighted average volatility of 96.74% and the weighted average expected term of 0.4 years.

The Company has reserved for future issuance the following shares of common stock related to the potential warrant exercise, exercise of stock options, and the employee stock purchase plan:

The Company’s chief executive officer and member of the board of directors is also an Executive Partner at MPM Asset Management, LLC, which holds an investment in the Company’s common stock.

In May 2020, the Company closed an underwritten public offering whereby the Company sold 5,555,556 shares of common stock at a price of $18.00 per share. The aggregate net proceeds received by the Company were $93.7 million, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. The offering allows for an additional 833,333 shares to be issued pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock.

The following information should be read in conjunction with the unaudited financial information and the notes thereto included in this Quarterly Report on Form 10-Q and the audited financial information and the notes thereto included in our Annual Report on Form 10-K that was filed with the Securities and Exchange Commission, or SEC, on March 5, 2020.

We are a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies. We are developing our lead product candidate, entinostat, a once-weekly, oral, small molecule, Class I HDAC inhibitor, in combination with exemestane and several approved PD-1/PD-L1 antagonists. Our pipeline also includes SNDX-6352, or axatilimab, a monoclonal antibody that blocks the colony stimulating factor 1, or CSF-1 receptor, as well as SNDX-5613, targeting the binding interaction of menin with the mixed lineage leukemia 1 (MLL1) protein for the treatment of MLL-rearranged, or MLLr, acute leukemias and nucleophosmin 1, or NPM1, mutant acute myeloid leukemia (AML). We plan to continue to leverage the technical and business expertise of our management team and scientific collaborators to license, acquire and develop additional cancer therapies to expand our pipeline.

We have no products approved for commercial sale and have not generated any product revenues from product sales to date. We continue to incur significant research and development and other expenses related to our ongoing operations. As a result, we are not and have never been profitable and have incurred losses in each period since our inception in 2005. For the three months ended March 31, 2020 and 2019, we reported a net loss of $15.2 million and $14.3 million, respectively. We reported a net loss attributable to shareholders as of March 31, 2020, of $19.3 million. As of March 31, 2020, we had an accumulated deficit of $510.7 million, which included non-cash charges for stock-based compensation, preferred stock accretion and extinguishment charges. As of March 31, 2020, we had cash, cash equivalents and short-term investments of $99.0 million.

We continue to monitor our daily operations and program timelines during the evolving coronavirus 2019 (COVID-19) pandemic. The health and safety of our employees as well as the patients and people participating in and operating our clinical trials are of paramount importance. COVID-19 has not impacted our financial guidance or changed our timelines for clinical data in 2020, to date.

We continue to anticipate that the E2112 trial will reach 410 death events this quarter, which will trigger the final overall survival (OS) analysis. E2112 is the NCI-sponsored, ECOG-ACRIN-led Phase 3 registration trial of entinostat, a Class I selective HDAC inhibitor, plus exemestane in advanced hormone receptor positive, human epidermal growth factor receptor 2 negative (HR+, HER2-) breast cancer. A positive OS assessment would allow us to file for full regulatory approval in the U.S.

The E2112 trial design was informed by the Phase 2b ENCORE 301 trial, the results of which led to entinostat's Breakthrough Therapy designation in HR+ breast cancer, in which patients receiving the entinostat/exemestane combination demonstrated a clinically meaningful OS benefit over treatment with exemestane alone. In preparation for the potential launch of entinostat in the U.S. in 2021, we are actively engaged in the expansion of our commercial and medical affairs functions.

We recently announced initial clinical data from the Phase 1 portion of its ongoing open-label Phase 1/2 AUGMENT-101 trial of SNDX-5613, our potent, highly selective oral menin inhibitor. Data presented serve as the first clinical evidence that inhibition of the menin-MLL1 interaction can induce response in patients with mixed lineage leukemia rearranged (MLL-r) acute leukemias. The presentation, which was featured at the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting I, also highlighted preclinical findings, including data recently published in Cancer Cell and Science magazine, supporting the potential of single-agent menin-MLL inhibition to serve as an effective intervention for both MLL-r acute leukemias and nucleophosmin (NPM1) mutant acute myeloid leukemia (AML). A copy of the presentation is available on our website under Publications, Menin-MLLR Inhibitors.

The AUGMENT-101 trial is a Phase 1/2 open-label trial designed to evaluate the safety, tolerability, pharmacokinetics and efficacy of orally administered SNDX-5613. The Phase 1 dose escalation portion of AUGMENT-101 was recently separated into two cohorts based on concomitant treatment with a strong CYP3A4 inhibitor. Arm A will enroll patients not receiving a strong CYP3A4 inhibitor, while Arm B will enroll patients receiving a strong CYP3A4 inhibitor. The Phase 1 dose escalation portion of AUGMENT-101 is currently enrolling adults with relapsed/refractory acute leukemias including MLL-r and NPM1 mutant acute leukemias and is expected to establish a recommended Phase 2 dose for both cohorts by the fourth quarter of 2020. The Phase 2 portion will evaluate efficacy, as defined by complete response rate (per International Working Group response criteria), across three expansion cohorts: MLL-r acute lymphoblastic leukemia (ALL), MLL-r AML and NPM1 mutant AML. We expect to present additional results from AUGMENT-101 at a medical conference in the fourth quarter of 2020.

We recently announced that SNDX-5613 was granted Orphan Drug Designation for the treatment of adult and pediatric AML by the U.S. Food and Drug Administration (FDA).

Enrollment continues across the Phase 1/2 trial evaluating axatilimab, our anti-CSF-1R monoclonal antibody, for the treatment of chronic graft versus host disease (cGVHD). The Phase 1 portion continues to explore alternate dose and schedules, while the Phase 2 expansion is evaluating the benefit of treatment at 1 mg/kg every two weeks. We expect to present additional results from the Phase 1/2 trial in the fourth quarter of 2020.

Data from the Phase 1 trials exploring axatilimab, both as a monotherapy and in combination with IMFINZI® (durvalumab) in patients with locally-advanced or metastatic solid tumors, were summarized in two oral presentations at the AACR Virtual Annual Meeting I. The data indicate that axatilimab is tolerated well in solid tumor patients, and provide evidence of its ability to deplete circulating pro-inflammatory monocytes. A recommended Phase 2 dose of axatilimab for the treatment of patients with solid tumors was determined as monotherapy and in combination with IMFINZI® (durvalumab). A copy of each presentation is available on our website under Publications, Axatilimab.

With the global spread of the ongoing COVID-19 pandemic in the first and second quarters of 2020, we have implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on our employees and our business. While we are not experiencing financial impacts at this time, given the global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic, our business, financial condition, results of operations and growth prospects could be materially adversely affected. We continue to closely monitor the COVID-19 situation as we evolve our business continuity plans and response strategy. In March 2020, our workforce transitioned to working remotely. We are currently considering plans to reopen our offices to allow employees to return to the office, which will be based on a approach that is principles-based and local in design, with a focus on patient continuity, employee safety and optimal work environment.

We are working closely our third-party manufacturers, distributors and other partners to manage our supply chain activities and mitigate potential disruptions to our product supplies as a result of the COVID-19 pandemic. We currently expect to have adequate supplies of entinostat, axatilimab and SNDX-5613 in 2020, as well as adequate commercial product availability for entinostat to support a planned U.S. launch if the E2112 trial is positive and the FDA approves entinostat in 2021. If the COVID-19 pandemic persists for an extended period of time and begins to impact essential distribution systems such as FedEx and postal delivery or if it results in facility closures facility closures for cleaning and/or insufficient staff, we could experience disruptions to our supply chain and operations, and associated delays in the manufacturing and supply of our products, which would adversely impact our ability to generate sales of and revenues from entinostat, if approved, and to continue our clinical trial operations.

With respect to clinical development, we have taken measures to implement remote and virtual approaches, including remote patient monitoring where possible, to maintain patient safety and trial continuity and to preserve study integrity. We have not yet, but may experience a disruption or delay in our ability to initiate trial sites and enroll and assess patients. As the COVID-19 pandemic continues, we anticipate a potential impact on our ability to maintain patient enrollment in the AUGMENT-101 and cGVHD trials. We could also see an impact on the ability to supply study drug, report trial results, or interact with regulators, ethics committees or other important agencies due to limitations in regulatory authority employee resources or otherwise. In addition, we rely on contract research organizations or other third parties to assist us with clinical trials, and we cannot guarantee that they will continue to perform their contractual duties in a timely and satisfactory manner as a result of the COVID-19 pandemic. If the COVID-19 pandemic continues and persists for an extended period of time, we could experience significant disruptions to our clinical development timelines, which would adversely affect our business, financial condition, results of operations and growth prospects.

With our strong cash balance, including the proceeds of our recent registered direct offering and draw of the first tranche under our loan agreement, we anticipate having sufficient liquidity to make planned investments in our business this year in support of our long-term growth strategy. We believe that our cash, cash equivalents and marketable securities as of May 7, 2020 will fund our current operating plans through at least the next 12 months. However, our operating plan may change as a result of many factors currently unknown to us, and we may need to seek additional funds sooner than planned, through public or private equity or debt financings, third-party funding, marketing and distribution arrangements, as well as other collaborations, strategic alliances and licensing arrangements, or any combination of these approaches. However, the COVID-19 pandemic continues to rapidly evolve and has already resulted in a significant disruption of global financial markets. If the disruption persists and deepens, we could experience an inability to access additional capital, which could in the future negatively affect our operations.

While we continue evaluation whether the COVID-19 pandemic will adversely affect our business operations and financial results, our clinical development and regulatory efforts, our corporate development objectives and the value of and market for our common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements in the U.S., Europe and other countries, and the effectiveness of actions taken globally to contain and treat the disease. For example, if remote work policies for certain portions of our business, or that of our business partners, are extended longer than we currently expect, we may need to reassess our priorities and our corporate objectives for the year.

To date, we have not generated any product revenues. Our ability to generate revenue and become profitable depends upon our ability to obtain marketing approval of and successfully commercialize our product candidates. Our revenues for the three months ended March 31, 2020 and 2019 have been solely derived from our license, development and commercialization agreement with Kyowa Kirin Co., Ltd., or KKC, under which we granted KKC an exclusive license to develop and commercialize entinostat in Japan and Korea, or the KKC license agreement. In 2015, we received a $25.0 million upfront payment from KHK, inclusive of an equity investment. We allocated $17.3 million of the upfront payment to the license fee, and such fee is being recognized as revenue ratably over our expected performance period (currently expected to be through 2029). The balance of the upfront payment of $7.7 million was allocated to KKC’s purchase of shares of our convertible preferred stock.

In October 2017, KKC enrolled the first Japanese patient into a local pivotal study of entinostat for the treatment of hormone receptor positive, human epidermal growth factor 2 negative breast cancer. In accordance with the terms of the KKC License Agreement, in December 2017 we received a $5.0 million milestone payment from KKC for achievement of the development milestone.

Since our inception, we have primarily focused on our clinical development programs. Research and development expenses consist primarily of costs incurred for the development of our product candidates and include:

Internal and external research and development costs are expensed as they are incurred. Cost-sharing amounts received by us are recorded as reductions to research and development expense. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations or other information provided to us by our vendors.

Research and development activities are central to our business model. Drug candidates in late 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 late-stage clinical trials. We plan to continue to spend a significant amount of our resources on research and development activities for the foreseeable future as we continue to advance the development of our product candidates. The amount of research and development expenses allocated to external spending will continue to grow, while we expect our internal spending to grow at a slower and more controlled pace. From inception through March 31, 2020, we have incurred $264.3 million in research and development expenses.

It is difficult to determine, with certainty, the duration and completion costs of our current or future preclinical programs, clinical studies and clinical trials of our product candidates. The duration, costs and timing of clinical studies and clinical trials of our product candidates will depend on a variety of factors that include, but are not limited to, the following:

In addition, the probability of success for each drug product candidate will depend on numerous factors, including competition, manufacturing capability and commercial viability. The successful development of our product candidates is highly uncertain. At this time, we cannot reasonably estimate the nature, timing or costs of the efforts that will be necessary to complete the remainder of the development of our product candidates for the period, if any, in which material net cash inflows from these potential product candidates may commence. Clinical development timelines, the probability of success and development costs can differ materially from expectations.

General and administrative expenses consist primarily of employee-related expenses, including salaries, benefits, non-cash stock-based compensation and travel expenses, for our employees in executive, finance, business development and support functions. Other general and administrative expenses include facility-related costs not otherwise allocated to research and development expenses and accounting, tax, legal and consulting services. We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our continued research and development and potential commercialization of our product candidates. Additionally, if and when we believe a regulatory approval of the first product candidate appears likely, we anticipate an increase in payroll and related expenses as a result of our preparation for commercial operations, especially as it relates to the sales and marketing of our product candidates.

Interest expense consists primarily of interest expense on our term loan, operational and capital leases.

Interest income consists of interest income earned on our cash, cash equivalents and short-term investment balances.

Our management’s discussion and analysis of financial condition and results of operations are based on our financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities 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 are believed to be 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. Actual results may differ from these estimates under different assumptions or conditions. In making estimates and judgments, management employs critical accounting policies.

There have been no material changes to our critical accounting policies described in the “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in our Annual Report.

	Three Months Ended March 31,						Increase (Decrease)
	2020			2019			$			%
	(In thousands)
Revenue:
License fees	$	379		$	379		$	—			0	%
Total revenues		379			379			—			0	%
Operating expenses:
Research and development		9,562			11,279			(1,717	)		-15	%
General and administrative		5,917			3,911			2,006			51	%
Total operating expenses		15,479			15,190			289			2	%
Loss from operations		(15,100	)		(14,811	)		289			2	%
Other (expense) income:
Interest expense		(449	)		—			(449	)		—
Interest income		333			452			(119	)		-26	%
Other (expense) income		(20	)		57			(77	)		-135	%
Total other (expense) income		(136	)		509			(645	)		-127	%
Net loss	$	(15,236	)	$	(14,302	)	$	934			7	%

For the three months ended March 31, 2020 and 2019, we recognized license fees of $0.4 million and $0.4 million respectively, derived from the KKC license agreement.

For the three months ended March 31, 2020, our total research and development expenses decreased $1.7 million, or 15%, to $9.6 million from $11.3 million for the comparable quarter in the prior year. The decrease in research and development expenses was primarily due to decreases in clinical activities of $1.4 million, a decrease in employee related expenses of $0.6 million partially offset by increased professional fees of $0.3 million. The decrease in clinical activities was primarily due to reduced clinical activities in our ENCORE programs of $2.3 million partially offset by an increase in clinical activities for our SNDX-5613 program of $0.9 million. The decrease in employee-related expenses is primarily due to a decrease in headcount. We expect research and development expenses to fluctuate from quarter to quarter depending on the timing of clinical trial activities, clinical manufacturing and other development activities.

	Three Months Ended March 31,				Increase (Decrease)
	2020		2019		$			%
	(In thousands)
External research and development expenses	$	6,146	$	7,273	$	(1,127	)		-15	%
Internal research and development expenses		3,416		4,006		(590	)		-15	%
Total research and development expenses	$	9,562	$	11,279	$	(1,717	)		-15	%

For the three months ended March 31, 2020, our total general and administrative expenses increased $2.0 million, or 51%, to $5.9 million from $3.9 million for the comparable period in the prior year. The increase in general and administrative expenses was primarily due to increased pre-commercialization activities of $1.2 million, increased employee expenses of $0.7 million and increased director’s and officer’s insurance of $0.1 million. The increase in employee expenses is primarily due to increased headcount of $0.5 million and increased stock compensation expense of $0.2 million.

For the three months ended March 31, 2020, interest expense, decreased from the comparable period in the prior year primarily due to the interest expense on the loan payable.

For the three months ended March 31, 2020, interest income, decreased from the comparable period in the prior year primarily due interest income on a decrease average balance on cash equivalents and short-term investments.

As of March 31, 2020, we had cash, cash equivalents and short-term investments totaling $99.0 million. Our operations have been primarily financed by net proceeds from our initial public offering, our follow-on stock offerings and proceeds from our license agreements. We believe that our present cash, cash equivalents and short-term investments will fund our projected operating expenses and capital expenditure requirements for at least the next 12 months. In addition to our existing cash, cash equivalents and short-term investments, we are eligible to receive research and development funding and to earn milestone and other contingent payments for the achievement of defined collaboration objectives and certain development, regulatory and commercial milestones and royalty payments under our collaboration agreements. Our ability to earn these milestone and contingent payments and the timing of achieving these milestones is primarily dependent upon the outcome of our collaborators’ research and development activities and is uncertain at this time.

In May 2020, we sold 5,555,556 shares of our common stock at a price per share of $18.00 for net proceeds of approximately $93.7 million.

In January 2020, we sold 3,036,719 shares of our common stock at a price per share of $8.00 and pre-funded warrants to purchase 1,338,287 shares of our common stock for gross proceeds of approximately $35.0 million. Upon the completion of the January 2020 offering, we had 5,838,287 pre-funded warrant shares outstanding. The pre-funded warrants are exercisable into shares of common stock for $0.0001 per share. The pre-funded warrants enable the holder to make a cash investment in our common stock without increasing their beneficial ownership in our common stock because the shares of common stock underlying the pre-funded warrant are not issued or issuable until the warrant is actually exercised or becomes exercisable without exceeding the ownership limitations set forth in the pre-funded warrant.

In March 2019, we issued to certain investors an aggregate of 2,095,039 shares of our common stock and 2,500,000 pre-funded warrants to purchase shares of our common stock, at a price of $6.00 per share of common stock and $5.9999 for each pre-funded warrant. We sold the shares of common stock and prefunded warrants together with two series of warrants, Series 1 warrants and Series 2 warrants, to purchase an aggregate of 4,595,039 shares of our common stock. The pre-funded warrants are exercisable into shares of common stock for $0.0001 per share. Each Series 1 warrant has an initial exercise price of $12.00 per share of common stock and each Series 2 warrant has an initial exercise price of $18.00 per share of common stock, in each case subject to certain adjustments. The Series 1 warrants and Series 2 warrants contain a one-time exercise price adjustment. If we sell shares or share equivalents at less than $12.00 per share at a time when our Series 1 warrants and Series 2 warrants are outstanding, then an exercise price for those warrants would be adjusted downward, which will result in us receiving less proceeds than we otherwise would and

could result in further dilution to our stockholders if such warrants were then exercised. As a result of the January 2020 offering, the initial exercise price of the Series 1 warrants was reduced to $10.00 per share and the initial exercise price of the Series 2 warrants was reduced to $13.00 per share.

The COVID-19 pandemic continues to rapidly evolve and has already resulted in a significant disruption of global financial markets. If the disruption persists and deepens, we could experience an inability to access additional capital, which could in the future negatively affect our operations.

On February 7, 2020, we entered into a loan and security agreement, or the Loan Agreement, with Hercules Capital, Inc., or Hercules, which provides for aggregate maximum borrowings of up to $30.0 million, consisting of (i) a term loan of up to $20.0 million, which was funded on February 7, 2020, and (ii) subject to Hercules’ investment committee approval, an additional term loan of up to $10.0 million, available for borrowing from February 7, 2020 to December 15, 2020, which we refer to as the Tranche 2 Advance. Borrowings under the Loan Agreement are repayable in monthly interest-only payments through October 1, 2021, or April 1, 2022 if the Performance Milestone is achieved. After the interest-only payment period, borrowings under the Loan Agreement are repayable in equal monthly payments of principal and accrued interest until the maturity date of the loan, which is either (i) September 1, 2023, or (ii) March 1, 2024 upon achievement of the Performance Milestone. Borrowings under the Loan Agreement bear interest at an annual rate equal to the greater of (i) 9.85% or (ii) 5.10% plus the Wall Street Journal prime rate. The Wall Street Journal prime rate as of March 31, 2020, was 3.45%. At our option, we may prepay all, but not less than all, of the outstanding borrowings, subject to a prepayment premium. Borrowings under the Loan Agreement are collateralized by substantially all of our and our subsidiaries personal property and other assets, other than our intellectual property. For additional information regarding the Loan Agreement with Hercules, see Note 12 to our condensed consolidated financial statements located elsewhere in this report.

In August 2019, we entered into a new sales agreement with Cowen and Company, LLC, or Cowen, under which we may issue and sell shares of our common stock having aggregate sales proceeds of up to $50.0 million from time to time pursuant to the ATM program, or the 2019 ATM Program. Cowen is not required to sell any specific amount but acts as our sales agent using commercially reasonable efforts consistent with their normal trading and sales practices. This agreement replaced the sales agreement signed in April 2017. Shares sold pursuant to the sales agreement will be sold pursuant to a shelf registration statement on Form S-3 (Registration No. 333-233564), which was declared effective on September 10, 2019. Our common stock will be sold at prevailing market prices at the time of the sale; and as a result, prices may vary. We will pay Cowen up to 3% of the gross proceeds from any common stock sold through the sales agreement. The proceeds from the offerings, if any, will be used to fund the research and development of our product candidates, acquire or invest in businesses, products or technologies that are complementary to our own, although we have no current plans, commitments or agreements with respect to any acquisitions as of the date of this prospectus, and for working capital and general corporate purposes. As of March 31, 2020, $50.0 million of common stock remained available for sale under the 2019 ATM Program.

In April 2017, we entered into a sales agreement with Cowen, under which we issued and sold shares of our common stock having aggregate sales proceeds of up to $50.0 million from time to time, or the 2017 ATM Program. Shares sold pursuant to the sales agreement were sold pursuant to a shelf registration statement on Form S-3 (Registration No. 333-217172), which was declared effective on April 20, 2017. The proceeds from the offerings, if any, were used for general corporate purposes, including expenditures for research and development of our drug products. In 2019, prior to the effectiveness of the 2019 ATM Program, we sold 140,819 shares of common stock, with net proceeds of $0.9 million.

Our primary uses of capital are, and we expect will continue to be, compensation and related expenses, third-party clinical research and development services, clinical costs, legal and other regulatory expenses and general overhead costs. We have based our estimates on assumptions that may prove to be incorrect, and we could use our capital resources sooner than we currently expect. Additionally, the process of testing drug candidates in clinical trials is costly, and the timing of progress in these trials is uncertain. We cannot estimate the actual amounts necessary to successfully complete the development and commercialization of our drug candidates or whether, or when, we may achieve profitability. Our future capital requirements will depend on many factors, including:

We have no products approved for commercial sale and have not generated any product revenues from product sales to date. Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings and additional funding from license and collaboration arrangements. Except for any obligations of our collaborators to reimburse us for research and development expenses or to make milestone payments under our agreements with them, we will not have any committed external source of liquidity.

We have incurred losses and cumulative negative cash flows from operations since our inception; and as of March 31, 2020, we had an accumulated deficit of $510.7 million. We anticipate that we will continue to incur significant losses for at least the next several years. We expect that our research and development and general and administrative expenses will continue to increase. As a result, we will need additional capital to fund our operations, which we may raise through a combination of the sale of equity, debt financings, or other sources, including potential collaborations. The COVID-19 pandemic continues to rapidly evolve and has already resulted in a significant disruption of global financial markets. If the disruption persists and deepens, we could experience an inability to access additional capital, which could in the future negatively affect our operations. To the extent that we raise additional capital through the future sale of equity or debt, the ownership interest of our stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing common stockholders. If we raise additional funds through collaboration arrangements in the future, we may have to relinquish valuable rights to our technologies, future revenue streams or drug 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 drug candidates that we would otherwise prefer to develop and market ourselves.

Net cash used in operating activities for the three months ended March 31, 2020, was $15.9 million and primarily consisted of our net loss of $15.2 million adjusted for non-cash items, including stock-based compensation of $1.8 million, a net decrease in operating assets and liabilities of $2.9 million, an investment amortization of $0.1 million and non-cash interest expense associated with the term loan of $0.1 million. The increased net loss is primarily due to increased pre-commercialization expenses, offset by decreased clinical trial activities and CMC expenses. The net decrease in operating assets and liabilities primarily consisted of increased accounts payable of $2.8 million, offset by decreased prepayments and deposits of $2.5 million, decreased accrued expenses and other liabilities of $2.5 million and decreased deferred revenue of $0.4 million.

Net cash used in operating activities for the three months ended March 31, 2019, was $16.8 million and primarily consisted of our net loss of $14.3 million adjusted for non-cash items, including stock-based compensation of $1.6 million, a net decrease in operating assets and liabilities of $3.9 million and a net decrease in investment amortization of $0.2 million. The increase in our net loss was primarily due to the increase in our clinical trial activities and CMC expenses. The significant items in the decrease in operating assets and liabilities included an increase in prepaid expenses and other assets of $2.5 million and a decrease in deferred revenue of $0.4 million and a decrease in accrued expenses and other liabilities of $4.0 million partially offset by an increase in accounts payable of $2.9 million.

Net cash used in investing activities for the three months ended March 31, 2020, was $19.1 million and was primarily due to the purchase of $34.9 million of available-for-sale marketable securities from the proceeds of the direct offering partially offset by $15.8 million of proceeds from the maturities of available-for-sale securities, which will primarily be used to fund the next period’s operating activities.

Net cash provided by investing activities for the three months ended March 31, 2019, was $12.8 million and was primarily due to the $33.4 million of proceeds from the maturities of available-for-sale securities partially offset by the purchase of $20.6 million of available-for-sale marketable securities.

Net cash provided by financing activities for the three months ended March 31, 2020, of $55.0 million was primarily due to the proceeds from our direct placement, net of fees, of $34.9 million, proceeds from our term loan of $19.7 million, proceeds from stock option exercises of $0.3 million and employee participation in our Employee Stock Purchase Plan of $0.1 million.

Net cash provided by financing activities for the three months ended March 31, 2019, of $28.4 million was primarily due to proceeds from sales of shares of our common stock and a pre-funded warrant, net of fees, of $27.4 million, our at-the-market offering, net of discounts and commissions of $0.8 million.

On February 7, 2020, we entered into a Loan Agreement with Hercules, which provides for aggregate maximum borrowings of up to $30.0 million, consisting of (i) a term loan of up to $20.0 million, which was funded on February 7, 2020, and (ii) subject to Hercules’ investment committee approval, an additional term loan of up to $10.0 million, available for borrowing from February 7, 2020 to December 15, 2020, which we refer to as the Tranche 2 Advance. Borrowings under the Loan Agreement are repayable in monthly interest-only payments through October 1, 2021, or April 1, 2022 if the Performance Milestone is achieved. After the interest-only payment period, borrowings under the Loan Agreement are repayable in equal monthly payments of principal and accrued interest until the maturity date of the loan, which is either (i) September 1, 2023, or (ii) March 1, 2024 upon achievement of

the Performance Milestone. Borrowings under the Loan Agreement bear interest at an annual rate equal to the greater of (i) 9.85% or (ii) 5.10% plus the Wall Street Journal prime rate. At our option, we may prepay all, but not less than all, of the outstanding borrowings, subject to a prepayment premium. Borrowings under the Loan Agreement are collateralized by substantially all of our and our subsidiaries personal property and other assets, other than our intellectual property. As of March 31, 2020, $20.0 million was outstanding under the Loan Agreement. For additional information regarding the Loan Agreement with Hercules, see Note 13 to our condensed consolidated financial statements located elsewhere in this report.

Other than the Loan Agreement, there have been no material changes to our contractual obligations from those described in our Annual Report on Form 10-K that was filed with the SEC on March 5, 2020.

We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the SEC.

In April 2012, the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, was enacted. Section 107 of the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have irrevocably elected not to avail ourselves of this extended transition period and, as a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for other public companies.

The market risk inherent in our financial instruments and in our financial position represents the potential loss arising from adverse changes in interest rates. As of March 31, 2020, we had cash and cash equivalents of $44.6 million, consisting of overnight investments, interest-bearing money market funds, commercial papers and short-term corporate bonds, and short-term investments of $54.4 million, consisting of commercial paper, highly rated corporate bonds and credit card asset backed securities. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates. The primary objectives of our investment activities are to ensure liquidity and to preserve principal while at the same time maximizing the income we receive from our marketable securities without significantly increasing risk. We have established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. Due to the short-term maturities of our cash equivalents and the low risk profile of our short-term investments, an immediate 100 basis point change in interest rates would not have a material effect on the fair market value of our cash equivalents and short-term investments.

We also have exposure to market risk on our Hercules Loan Agreement with Hercules. Our Loan Agreement accrues interest from its date of issue at a variable interest rate equal to greater of (i) 9.85% and (ii) 5.10% plus the Wall Street Journal prime rate. As of March 31, 2020, $20.0 million was outstanding under the Loan Agreement. The effect of a 100 basis points adverse change in market interest rates on our 2020 Loan Payable, in excess of applicable minimum floors, on our interest expense would be approximately $0.5 million.

We do not believe that inflation and changing prices had a significant impact on our results of operations for any periods presented herein.

We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in the reports that we file or submit under the Securities and Exchange Act of 1934 is (1) recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms and (2) accumulated and communicated to our management, including our principal executive officer and principal financial officer, to allow timely decisions regarding required disclosure.

As of March 31, 2020, our management, with the participation of our principal executive officer and principal financial officer, evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities and Exchange Act of 1934). Our 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. Our principal executive officer and principal financial officer have

concluded based upon the evaluation described above that, as of March 31, 2020, our disclosure controls and procedures were effective at the reasonable assurance level.

There was no change in our internal control over financial reporting that occurred during our most recent fiscal quarter that materially affected, or is reasonably likely to materially affect, our internal control over financial reporting. We have not experienced any material impact to our internal controls over financial reporting despite the fact that our employees are working remotely due to the COVID-19 pandemic. We are continually monitoring and assessing the COVID-19 situation on our internal controls to minimize the impact on their design and operating effectiveness.

In the ordinary course of business, we are from time to time involved in lawsuits, claims, investigations, proceedings, and threats of litigation relating to intellectual property, commercial arrangements and other matters. While the outcome of these proceedings and claims cannot be predicted with certainty, as of March 31, 2020, we were not party to any material legal or arbitration proceedings. No governmental proceedings are pending or, to our knowledge, contemplated against us.

An investment in shares of our common stock involves a high degree of risk. You should carefully consider the following information about these risks, together with the other information appearing elsewhere in this Quarterly Report on Form 10-Q, including our financial statements and related notes hereto, before deciding to invest in our common stock. The occurrence of any of the following risks could have a material adverse effect on our business, financial condition, results of operations and future growth prospects or cause our actual results to differ materially from those contained in forward-looking statements we have made in this report and those we may make from time to time. In these circumstances, the market price of our common stock could decline; and you may lose all or part of your investment. We cannot assure you that any of the events discussed below will not occur.

In December 2019, a novel strain of coronavirus, SARS-CoV-2, causing COVID-19, was initially reported and has since been declared a pandemic by the World Health Organization. The COVID-19 pandemic has resulted in travel and other restrictions in order to reduce the spread of the disease, including state and local orders across the United States and other countries worldwide, which, among other things, direct individuals to shelter at their places of residence, direct businesses and governmental agencies to cease non-essential operations at physical locations, prohibit certain non-essential gatherings, and order cessation of non-essential travel. In response to these public health directives and orders, we have implemented work-from-home policies for our employees. The effects of the executive orders, the shelter-in-place (“SIP”) orders and our work-from-home policies may negatively impact productivity, disrupt our business and delay our clinical programs and timelines, the magnitude of which will depend, in part, on the length and severity of the restrictions and other limitations on our ability to conduct our business in the ordinary course. These and similar, and perhaps more severe, disruptions in our operations could negatively impact our business, operating results and financial condition.

Quarantines, SIP and similar government orders related to COVID-19 may adversely impact our business operations and the business operations of our contract research organizations conducting our clinical trials and our third-party manufacturing facilities in the United States and other countries. In particular, if the COVID-19 pandemic persists for an extended period of time and begins to impact essential distribution systems such as FedEx and postal delivery or if it results in facility closures facility closures for cleaning and/or insufficient staff, we could experience disruptions to our supply chain and operations, and associated delays in the manufacturing and supply of our products, which would adversely impact our ability to generate sales of and revenues from entinostat, if approved, and to continue our clinical trial operations.

In addition, our clinical trials may be affected by the COVID-19 pandemic. For example, clinical site initiation and patient enrollment may be delayed due to prioritization of hospital resources toward the COVID-19 pandemic. Patients may not be able to comply with clinical trial protocols if quarantines impede patient movement or interrupt healthcare services. Similarly, our ability to recruit and retain patients and principal investigators and site staff who, as healthcare providers, may have heightened exposure to COVID-19, could be limited, which in turn could adversely impact our clinical trial operations. As a result, we may face delays in meeting our anticipated timelines for our ongoing and planned clinical trials.

The spread of COVID-19, which has caused a broad impact globally, may materially affect us economically. While the potential economic impact brought by, and the duration of, COVID-19 may be difficult to assess or predict, a widespread pandemic could result in significant disruption of global financial markets, reducing our ability to access capital, which could in the future negatively affect our liquidity. In addition, a recession or market correction resulting from the spread of COVID-19 could materially affect our business and the value of our common stock.

The global pandemic of COVID-19 continues to rapidly evolve. The extent to which the COVID-19 pandemic impacts our business, our clinical development and regulatory efforts will depend on future developments that are highly uncertain and cannot be predicted with confidence, such as the duration of the outbreak, travel restrictions, quarantines, SIP orders, social distancing requirements, business closures in the United States and other countries, and the effectiveness of actions taken in the United States and other countries to contain and treat the disease. Accordingly, we do not yet know the full extent of potential delays or impacts on our business, our clinical and regulatory activities, healthcare systems or the global economy as a whole. However, these impacts could adversely affect our business, financial condition, results of operations and growth prospects.

In addition, to the extent the ongoing COVID-19 pandemic adversely affects our business and results of operations, it may also have the effect of heightening many of the other risks and uncertainties described in this “Risk Factors” section.

If the Phase 3 clinical trial of entinostat in combination with exemestane in advanced HR+, HER2- breast cancer patients fails to demonstrate safety and efficacy to the satisfaction of regulatory authorities or does not otherwise produce positive results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of entinostat.

Before obtaining marketing approval from regulatory authorities for the sale of entinostat, we or our collaborators must conduct extensive trials to demonstrate the safety and efficacy of entinostat in humans. We have entered into an arrangement with ECOG-ACRIN Cancer Research Group, or ECOG-ACRIN, to conduct the Phase 3 clinical trial of entinostat in combination with exemestane in advanced hormone receptor positive, human epidermal growth factor receptor 2 negative, or (HR+, HER2-, breast cancer patients. The National Cancer Institute, or NCI, designed the trial to measure two primary endpoints, progression-free survival, or PFS, and overall survival, or OS. We received the final PFS analysis from ECOG-ACRIN in October 2018 and we expect to receive the final OS analysis no later than the second quarter of 2020. In October 2018, ECOG-ACRIN informed us that the trial did not achieve the first primary endpoint of improving PFS, which would have provided the earliest regulatory filing opportunity. In accordance with the trial protocol, ECOG-ACRIN is confidentially holding the findings from the PFS analysis until reporting final OS results. We will not be able to submit an NDA unless and until we receive data demonstrating that the trial has achieved the primary endpoint for OS. In addition, based on scientific advice that we received from the European Medicines Agency, the current Phase 3 clinical trial may not be sufficient to receive regulatory approval in Europe for entinostat to treat advanced HR+, HER2- breast cancer, and it is unclear whether we would be able to complete an alternate clinical trial that would be sufficient.

Despite the results reported in our Phase 2b clinical trial for entinostat in advanced estrogen receptor positive, or ER+, breast cancer, we do not know whether the Phase 3 clinical trial in advanced HR+, HER2- breast cancer will demonstrate adequate efficacy and safety to result in regulatory approval to market entinostat in any particular cancer indications or jurisdiction. Additionally, while we do not expect that there will be overlapping toxicities between entinostat and exemestane, we cannot be certain that we will not observe these toxicities or unexpected adverse drug reactions in the Phase 3 clinical trial.

Clinical testing is expensive and difficult to design and implement, can take many years to complete and is inherently uncertain as to the outcome. A failure of one or more trials can occur at any stage of testing. The outcome of preclinical studies and early clinical trials may not accurately predict the success of later trials, and interim results of a trial do not necessarily predict final results. For example, with the emergence of the new therapies such as Verzenio, Kisqali, Ibrance and Piqray patients enrolled in the Phase 3 clinical trial may be different than those enrolled in our previous Phase 2b clinical trial in that they may have received a CDK 4/6 inhibitor prior to our trial and therefore may respond differently to treatment with entinostat. A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in advanced trials due to lack of efficacy or unacceptable safety profiles, notwithstanding promising results in earlier trials.

The failure of ECOG-ACRIN or the NCI to adequately perform its obligations and responsibilities in the conduct of the Phase 3 clinical trial or to meet expected deadlines could substantially harm our business because we may not obtain regulatory approval for entinostat in a timely manner, or at all.

We have entered into an arrangement with ECOG-ACRIN, pursuant to which it, with sponsorship and funding support by the NCI, is conducting the Phase 3 clinical trial of entinostat in combination with exemestane in advanced HR+, HER2- breast cancer patients. While we provide operational and logistical support for the trial, we have limited control of their activities. We cannot control whether ECOG-ACRIN will devote sufficient time and resources to the trial, including as a result of any reduction or delay in government funding or sponsorship of the activities of ECOG-ACRIN or the NCI. If ECOG-ACRIN or the NCI does not successfully carry out its obligations and responsibilities or meet expected deadlines or if the quality or accuracy of the clinical data that ECOG-ACRIN obtains is compromised due to the failure to adhere to Good Clinical Practices, or GCPs, clinical protocols, regulatory requirements or for other reasons, the Phase 3 clinical trial may be extended, delayed or terminated, and we may not be able to obtain regulatory approval for, or successfully commercialize, entinostat. As a result, our results of operations and the commercial prospects for entinostat would be harmed, our costs could increase and our ability to generate revenues could be delayed.

Although the Phase 3 clinical trial is being conducted by ECOG-ACRIN, we are responsible for ensuring that each of our trials is conducted in accordance with the applicable protocol and legal, regulatory and scientific standards, and our reliance on ECOG-ACRIN does not relieve us of our regulatory responsibilities. We are required to comply with GCP, which are regulations and guidelines enforced by the U.S. Food and Drug Administration, or FDA, the Competent Authorities of the Member States of the European Economic Area and foreign regulatory authorities for any product in clinical development. Regulatory authorities enforce GCP through periodic inspections of trial sponsors, principal investigators and clinical trial sites. If we fail to comply with applicable GCP, the clinical data generated in our trials may be deemed unreliable and the FDA or foreign regulatory authorities may require us to perform additional trials before approving our marketing applications. We cannot assure that upon inspection by a given regulatory

authority, such regulatory authority will determine that any of our trials comply with GCP requirements. In addition, we must conduct our trials with products produced under current Good Manufacturing Practices regulations, or cGMP requirements. Failure to comply with any of these regulations may require us to repeat preclinical and clinical trials, which would delay the regulatory development process.

If there are delays in completing the Phase 3 clinical trial for entinostat in advanced HR+, HER2- breast cancer, we will be delayed in commercializing entinostat, our development costs may increase and our business may be harmed.

The Phase 3 clinical trial of entinostat in combination with exemestane in advanced HR+, HER2- breast cancer commenced in the second quarter of 2014, and we expect to receive the final OS analysis no later than the second quarter of 2020. Our product development costs could increase if we experience delays in the overall number of survival events. Significant trial delays also could shorten any periods during which we may have the exclusive right to commercialize entinostat or allow our competitors to bring products to market before we do, which would impair our ability to successfully capitalize on entinostat and may harm our business, results of operations and prospects. Events that may result in a delay or unsuccessful completion of clinical development of entinostat include, among other things:

An inability by us to timely complete clinical development could result in additional costs to us or impair our ability to generate product revenues or development, regulatory, commercialization and sales milestone payments and royalties on product sales.

Although the NCI has entered into a Special Protocol Assessment, or SPA, agreement with the FDA relating to the pivotal Phase 3 clinical trial of entinostat for advanced HR+, HER2- breast cancer, this agreement does not guarantee any particular outcome with respect to regulatory review of the trial or any associated NDA for entinostat.

The protocol for the pivotal Phase 3 trial of entinostat in combination with exemestane in advanced HR+, HER2- breast cancer was reviewed and agreed upon by the FDA under a SPA agreement with the NCI. The SPA agreement allows for FDA evaluation of whether a clinical trial protocol could form the primary basis of an efficacy claim in support of an NDA. The SPA is an agreement that a Phase 3 clinical trial’s design, clinical endpoints, patient population and statistical analyses are sufficient to support the efficacy claim. Agreement on the SPA is not a guarantee of approval; and there is no assurance that the design of, or data collected from, the trial will be adequate to obtain the requisite regulatory approval. In October 2018, ECOG-ACRIN informed us that the trial did not achieve the statistical hurdle for the first primary endpoint of improving PFS, which would have provided the earliest regulatory filing opportunity. Further, obtaining clinical trial data meeting the OS endpoint in satisfaction of the SPA does not guarantee approval. The

SPA is not binding on the FDA if public health concerns unrecognized at the time the SPA was entered into become evident or other new scientific concerns regarding product safety or efficacy arise. In addition, upon written agreement of both the FDA and the NCI, the SPA may be changed, and the FDA retains significant latitude and discretion in interpreting the terms of the SPA and any resulting trial data. As a result, we do not know how the FDA will interpret the parties’ respective commitments under the SPA, how it will interpret the data and OS results from the pivotal Phase 3 clinical trial, whether the FDA will require that we conduct or complete one or more additional clinical trials to support potential approval or whether entinostat will receive any regulatory approvals. ECOG-ACRIN, with sponsorship and funding support from the NCI, is conducting the pivotal Phase 3 clinical trial, which began enrollment in the second quarter of 2014.

A breakthrough therapy designation by the FDA for entinostat may not lead to a faster development or regulatory review or approval process, and it does not increase the likelihood that entinostat will receive marketing approval.

We received breakthrough therapy designation from the FDA for entinostat when used in combination with exemestane based on the OS results from our completed Phase 2b clinical trial in advanced HR+, HER2- breast cancer. A breakthrough therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints. The Phase 2b trial showed statistically significant improvements in PFS, the primary endpoint, and OS, an exploratory endpoint. Receipt of a breakthrough therapy designation for a drug candidate may not result in a faster development process or review compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, the FDA may later decide that entinostat no longer meets the conditions for qualification or decide that the time period for FDA review will not be shortened. For instance, our Phase 3 trial in HR+, HER2- breast cancer patients failed to achieve one of its primary endpoints of improving PFS. We expect to receive final analysis on the second primary endpoint, OS, no later than the second quarter of 2020. If the results do not confirm the improvement in OS observed in our Phase 2b clinical trial, the FDA may rescind our breakthrough therapy designation.

We do not currently have any sales, marketing or distribution experience or infrastructure.

In order to market any approved product candidate in the future, we must build our sales, marketing, managerial and other non-technical capabilities or make arrangements with third parties to perform these services, as we do not presently have all of these capabilities. To develop our internal sales, distribution and marketing capabilities, we would have to invest significant amounts of financial and management resources in the future. For drugs where we decide to perform sales, marketing and distribution functions ourselves, we could face a number of challenges, including that:

Alternatively, we may rely on third parties to launch and market our product candidates, if approved. We may have limited or no control over the sales, marketing and distribution activities of these third parties and our future revenue may depend on the success of these third parties. Additionally, if these third parties fail to comply with all applicable legal or regulatory requirements, the FDA or another governmental agency could take enforcement action that could jeopardize their ability and our ability to market our product candidates.

We are currently developing several product candidates. If we are unable to successfully complete clinical development of, obtain regulatory approval for and commercialize our product candidates, our business prospects will be significantly harmed.

Entinostat, SNDX-5613 and axatilimab are currently our only product candidates. Our financial success will depend substantially on our ability to effectively and profitably commercialize our product candidates. In order to commercialize our product candidates, we will be required to obtain regulatory approvals by establishing that each of them is sufficiently safe and effective. The clinical and commercial success of our product candidates will depend on a number of factors, including the following:

If we fail to obtain regulatory approval for our product candidates, we will not be able to generate product sales, which will have a material adverse effect on our business and our prospects.

Our strategy of combining entinostat with immune checkpoint inhibitors has undergone limited clinical testing and we may fail to show that the combination is well tolerated and demonstrates additional clinical benefit from the combination.

Preclinical studies conducted by us and others suggest a strong rationale for combining entinostat with immune checkpoint inhibitors, including PD-1 pathway antagonists, to enhance the immune system’s ability to detect and eliminate tumor cells. Our approach was to conduct Phase 1 and 2 clinical trials in patients with tumors that are known to be responsive to PD-1 pathway antagonists and assess both the safety and efficacy of the combination of entinostat plus a PD-1 pathway antagonist. Our initial clinical data is supportive of our hypothesis as we have seen clinical benefit from the combination of entinostat plus pembrolizumab in patients with metastatic melanoma and non-small cell lung cancer. However, we have not yet sufficiently demonstrated a favorable risk-benefit of this combination in patients, and we may be unable to establish efficacy to warrant regulatory submission or approval. In the first quarter of 2019, we completed a full portfolio prioritization assessment and have determined to place the initiation of potential registration trials in non-small cell lung cancer and melanoma on hold until we receive final OS results from E2112.

Our strategy for developing SNDX-5613 has undergone limited clinical testing and we may fail to show that the drug is well tolerated and provides sufficient clinical benefit for patients.

Research suggests that certain acute leukemias, such as mixed lineage leukemia-rearranged, or MLLr, leukemias and nucleophosmin 1, or NPM1, mutant acute myeloid leukemia, or AML, are driven by the interaction of menin, a nuclear protein involved in transcription, with the N-terminus of MLL1 protein, a histone methyl transferase. In NMP1 mutant AML the interaction with Menin occurs via the wild type MLL1 protein, and in MLLr acute leukemias, the interaction occurs via a mutant form of MLL1, a fusion protein know as MLLr. MLLr results from a rare, spontaneous fusion between the N-terminus of the mixed lineage leukemia protein-1, or MLL1, and a host of signaling molecules and nuclear transcription factors. This fusion produces an aberrant transcription program that drives leukemic transformation. In pre-clinical animal models, small molecule inhibitors of the menin-MLL-r interactionmolecules, such as SNDX-5613, which bind to, and block the interaction of menin with either MLLr or MLL1, have demonstrated deep and durable single agent treatment effects in multiple leukemic xenograft models harboring MLL fusions or NPM1 mutations. Our strategy for developing SNDX-5613 is to conduct a Phase 1/2 clinical trial in patients with MLL-r leukemia and assess bothrelapsed/refractory acute leukemias. The Phase 1 portion of the trial is assessing the safety, tolerability and pharmacokinetics of SNDX-5613, and seeks to establish a recommended Phase 2 dose. The Phase 1 portion of the trial is open label, and we have released and may in the future release results from time to time that reflect very small numbers of patients which may not accurately predictive of safety or efficacy results later in the trial or in subsequent trials. The Phase 2 portion will evaluate efficacy of SNDX-5613, as defined by Complete Remission rate, across three expansion cohorts enrolling adult patients with MLL-r acute lymphoblastic leukemia, or ALL, MLL-r acute myeloid leukemia, or AML, and NPM1 mutant AML. If our initial clinical data lend support for our hypothesis, we plan to continue developing SNDX-5613 in one or more of these indications. At this time however, we have not yet sufficiently demonstrated a favorable risk-benefit of SNDX-5613 in patients, and we may be unable to establish sufficient efficacy to warrant continued development in one or more of these indications.

Our strategy for developing axatilimab has undergone limited clinical testing and we may fail to show that this drug is well tolerated and provides a clinical benefit for patients.

Preclinical studies suggest that CSF-1/CSF-1R signaling may be the key regulatory pathway involved in the expansion and infiltration of donor derived macrophages that mediate the disease processes involved in Graft Versus Host Disease, or cGVHD. Nonclinical studies and analysis of patient samples indicates that the cGVHD inflammatory disease process is a result of a complex interaction between host and donor immune cells including B cells, and regulatory T cells with M2 differentiated macrophages in target tissue appearing to represent the common distal mediator of fibrosis. Therefore, we hypothesize that a CSF-1R signal inhibitor such as axatilimab may play a meaningful role as a monotherapy agent in the treatment of cGVHD. Our approach is to conduct Phase 1 clinical trial with axatilimab in subjects with active cGVHD who have failed at least two prior lines of therapy. If our initial clinical data lend support for our hypothesis, we plan to continue developing axatilimab in this indication. At this time however, we have not yet sufficiently demonstrated a favorable risk-benefit of axatilimab in patients and we may be unable to establish sufficient efficacy to warrant continued development in this indication.

Interim top-line and preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publish interim top-line or preliminary data from our clinical trials. For example, in April 2020, we announced interim data from our Phase 1/2 clinical trial of SNDX-5613. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Preliminary or top-line data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. Preliminary or top-line data may include, for example, data regarding a small percentage of the patients enrolled in a clinical trial, and such preliminary data should not be viewed as an indication, belief or guarantee that other patients enrolled in such clinical trial will achieve similar results or that the preliminary results from such patients will be maintained. As a result, interim and preliminary data should be viewed with caution until the final data are available. Differences between preliminary or interim data and final data could significantly harm our business prospects and may cause the trading price of our common stock to fluctuate significantly.

We may be unable to transfer, qualify and validate an assay for determining peripheral monocyte levels to be used in conjunction with a future registration enabling non-small cell lung cancer, or NSCLC, trial.

In October 2018, we announced that we are proceeding with a registration trial in NSCLC patients whose disease has progressed after both platinum-based combination chemotherapy and a PD-1 antagonist therapy. We designed the trial to both validate a classical monocyte biomarker and demonstrate that the combination therapy of entinostat plus Keytruda is superior to standard of care chemotherapy in a high monocyte population. This trial will require testing patients for levels of circulating classical monocytes prior to treatment before assigning them to the appropriate arm of the trial. The assay that our academic collaborators have used to determine circulating levels of classical monocytes has not been developed or validated to the qualifications that the FDA may require for patient selection. We are working to measure circulating levels of cells, including monocytes, but we may not be able to

successfully transfer, qualify and validate an assay for determining peripheral monocyte levels that will be acceptable to the FDA. In the first quarter of 2019, we completed a full portfolio prioritization assessment and have determined to place the initiation of this trial on hold until we receive final OS results from E2112.

If we are or our collaborators are unable to enroll patients in clinical trials, these clinical trials may not be completed on a timely basis or at all.

The timely completion of clinical trials largely depends on patient enrollment. Many factors affect patient enrollment, including:

As a result of the above factors, there is a risk that our or our collaborators’ clinical trials may not be completed on a timely basis or at all.

The actions of Kyowa Kirin Co., Ltd., or KKC, Eddingpharm Investment Company Limited, or Eddingpharm, and any other current or future sublicensees could adversely affect our business.

We currently sublicense entinostat to third parties for development and commercialization in certain foreign jurisdictions. Specifically, we have a sublicense agreement with KKC under which we granted KKC an exclusive sublicense to develop and commercialize entinostat in Japan and Korea as well as a sublicense agreement with Eddingpharm under which we granted Eddingpharm an exclusive sublicense to develop and commercialize entinostat in China and select Asian countries. It is possible that any clinical trials conducted by KKC, Eddingpharm and other current or future sublicensees in their respective jurisdictions could have negative results, which in turn could have a material adverse effect on the development of entinostat for development and commercialization in the United States and the rest of the world.

We are dependent on UCB Biopharma Sprl, or UCB, to comply with the terms of our license agreement for axatilimab.

Our commercial success also depends upon our ability to develop, manufacture, market and sell axatilimab. In July 2016, we entered into the UCB license agreement pursuant to which we obtained a worldwide, sublicenseable, exclusive license to axatilimab, an IND-ready anti-CSF-1R monoclonal antibody. Under the UCB license agreement, we are dependent on UCB’s performance of its responsibilities and its cooperation with us. UCB may not perform its obligations under the UCB license agreement or otherwise cooperate with us. We cannot control whether UCB will devote the necessary resources to its obligations under the UCB license agreement, nor can we control the timing of its performance. Additionally, certain of the rights licensed to us under the UCB license agreement are in-licensed by UCB from third parties. We are dependent on UCB maintaining the applicable third-party license agreements in full force and effect, which may include activities and performance obligations that are not within our control. If any of these third-party license agreements terminate, certain of our rights to develop, manufacture, commercialize or sell axatilimab may be terminated as well. The occurrence of any of these events could adversely affect the development and commercialization of axatilimab, and materially harm our business.

We may be required to relinquish important rights to and control over the development and commercialization of our product candidates to our current or future collaborators.

Our collaborations, including any future strategic collaborations we enter into, could subject us to a number of risks, including:

We may periodically explore a variety of possible strategic collaborations in an effort to gain access to additional product candidates or resources. At the current time, we cannot predict what form such a strategic collaboration might take. We are likely to face significant competition in seeking appropriate strategic collaborators, and strategic collaborations can be complicated and time consuming to negotiate and document. We may enter into strategic collaborations that we subsequently no longer wish to pursue, and we may not be able to negotiate strategic collaborations on acceptable terms, or at all. We are unable to predict when, if ever, we will enter into any additional strategic collaborations because of the numerous risks and uncertainties associated with establishing them.

The regulatory approval processes of the FDA and foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable. Our inability to obtain regulatory approval for our product candidates could harm our business.

The time required to obtain approval by the FDA and foreign regulatory authorities is unpredictable, but typically takes many years following the commencement of preclinical studies and clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions. We have not obtained regulatory approval for any of our product candidates, and it is possible that we will never obtain regulatory approval for our existing product candidates or any future product candidates.

Due to the ongoing COVID-19 pandemic, it is possible that we could experience delays in the timing of our interactions with regulatory authorities due to absenteeism by governmental employees, inability to conduct planned physical inspections related to regulatory approval, or the diversion of regulatory authority efforts and attention to approval of other therapeutics or other activities related to COVID-19, which could delay anticipated approval decisions and otherwise delay or limit our ability to make planned regulatory submissions or obtain new product approvals. In addition, our product candidates could fail to receive regulatory approval from the FDA or foreign regulatory authorities for other reasons, including but not limited to:

The FDA or foreign regulatory authorities may require more information, including additional preclinical or clinical data, to support approval, which may delay or prevent approval and our commercialization plans, or may cause us to decide to abandon our development program. Even if we were to obtain approval, regulatory authorities may approve one or more of our product candidates for a more limited patient population than we request, may grant approval contingent on the performance of costly post-marketing trials, may impose a risk evaluation and mitigation strategy, or REMS, or foreign regulatory authorities may require the establishment or modification of a similar strategy that may, for instance, restrict distribution of entinostat and impose burdensome implementation requirements on us, or may approve it with a label that does not include the labeling claims necessary or desirable for the successful commercialization of entinostat, all of which could limit our ability to successfully commercialize our product candidates.

We are not developing entinostat as a monotherapy. A shortage in the supply of exemestane or other drugs used in combination with entinostat or cessation of development efforts for investigational agents being studied with entinostat could increase our development costs and adversely affect our ability to commercialize entinostat, and any unexpected adverse events with any of the drugs used in combination with entinostat could halt or delay development of entinostat.

Cancer drugs have from time to time been in short supply and, because many or all of these cancer drugs are also widely used in cancer treatment currently, we will compete with a broad range of healthcare providers and other companies for availability of those drugs. Any shortage of exemestane or other drugs that we are testing in combination with entinostat could adversely affect our ability to timely conduct the Phase 3 clinical trial in advanced HR+, HER2- breast cancer, our future potential Phase 3 clinical trial in NSCLC, any future clinical trials in melanoma, and if entinostat receives regulatory approval, to commercialize entinostat for treatment of advanced HR+, HER2- breast cancer, NSCLC, or melanoma. A shortage of supply may also result in an increase, which could be significant, in our costs of procuring exemestane.

Additionally, because entinostat is being developed for use in combination with other cancer treatments, the development of entinostat may be delayed or halted if unexpected adverse events occurring in patients are attributed to entinostat. Likewise, new adverse events emerging from commercialized or development stage drugs being administered with entinostat may limit or halt the potential of such combinations.

Our product candidates may not achieve adequate market acceptance among physicians, patients, healthcare payors and others in the medical community to be commercially successful.

Even if our product candidates receive regulatory approval, they may not gain sufficient market acceptance among physicians, patients, healthcare payors and others in the medical community. Our commercial success also depends on coverage and adequate reimbursement by third-party payors, including government payors, which may be difficult or time-consuming to obtain, may be limited in scope and may not be obtained in all jurisdictions in which we may seek to market our product candidates. The degree of market acceptance will depend on a number of factors, including:

If our product candidates are approved but do not achieve an adequate level of acceptance by physicians, hospitals, healthcare payors and patients, we may not generate sufficient revenue to become or remain profitable.

We rely on third-party suppliers to manufacture and distribute our clinical drug supplies for our product candidates, we intend to rely on third parties for commercial manufacturing and distribution of our product candidates and we expect to rely on third parties for manufacturing and distribution of preclinical, clinical and commercial supplies of any future product candidates.

We do not currently have, nor do we plan to acquire, the infrastructure or capability to manufacture or distribute preclinical, clinical or commercial quantities of drug substance or drug product, including our existing product candidates. While we expect to continue to depend on third-party manufacturers for the foreseeable future, we do not have direct control over the ability of these manufacturers to maintain adequate manufacturing capacity and capabilities to serve our needs, including quality control, quality assurance and qualified personnel. In additional, public health epidemics, such as the worldwide COVID-19 pandemic, may impact the ability of our existing or future manufacturers to perform their obligations to us.

We are dependent on our third-party manufacturers for compliance with cGMPs and for manufacture of both active drug substances and finished drug products. Facilities used by our third-party manufacturers to manufacture drug substance and drug product for commercial sale must be approved by the FDA or other relevant foreign regulatory agencies pursuant to inspections that will be conducted after we submit our NDA or relevant foreign regulatory submission to the applicable regulatory agency. If our third-party manufacturers cannot successfully manufacture materials that conform to our specifications and/or the strict regulatory requirements of the FDA or foreign regulatory agencies, they will not be able to secure and/or maintain regulatory approval for their manufacturing facilities. Furthermore, these third-party manufacturers are engaged with other companies to supply and/or manufacture materials or products for such companies, which also exposes our third-party manufacturers to regulatory risks for the production of such materials and products. As a result, failure to meet the regulatory requirements for the production of those materials and products may also affect the regulatory clearance of a third-party manufacturers’ facility. If the FDA or a foreign regulatory agency does not approve these facilities for the manufacture of our product candidates, or if it withdraws its approval in the future, we may need to find alternative manufacturing facilities, which would impede or delay our ability to develop, obtain regulatory approval for or market our product candidates, if approved.

Even if our product candidates receive regulatory approval, they may still face future development and regulatory difficulties.

Even if we obtain regulatory approval for our product candidates, they would be subject to ongoing requirements by the FDA and foreign regulatory authorities governing the manufacture, quality control, further development, labeling, packaging, storage, distribution, safety surveillance, import, export, advertising, promotion, recordkeeping and reporting of safety and other post-market information. The FDA and foreign regulatory authorities will continue to monitor closely the safety profile of any product even after approval. If the FDA or foreign regulatory authorities become aware of new safety information after approval of a product candidate, they may require labeling changes or establishment of a REMS or similar strategy, impose significant restrictions on its indicated uses or marketing, or impose ongoing requirements for potentially costly post-approval studies or post-market surveillance.

In addition, manufacturers of drug products and their facilities are subject to continual review and periodic inspections by the FDA and other regulatory authorities for compliance with cGMP regulations and standards. If we or a regulatory agency 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, a regulatory agency may impose restrictions on that product, the manufacturing facility or us, including withdrawal of the product from the market or suspension of manufacturing, or we may recall the product from distribution. If we, or our third-party manufacturers, fail to comply with applicable regulatory requirements, a regulatory agency may:

The occurrence of any event or penalty described above may inhibit our ability to commercialize and generate revenue from the sale of our product candidates.

Advertising and promotion of any product candidate that obtains approval in the United States will be heavily scrutinized by the FDA, the Department of Justice, the Department of Health and Human Services’ Office of Inspector General, state attorneys general, members of Congress, other government agencies and the public. Violations, including promotion of our products for unapproved (or off-label) uses, may be subject to enforcement letters, inquiries and investigations, and civil and criminal sanctions by the government. Additionally, foreign regulatory authorities will heavily scrutinize advertising and promotion of any product candidate that obtains approval in their respective jurisdictions.

In the United States, engaging in the impermissible promotion of our products for off-label uses can also subject us to false claims litigation under federal and state statutes, which can lead to administrative, civil and criminal penalties, damages, monetary fines, disgorgement, individual imprisonment, exclusion from participation in Medicare, Medicaid and other federal healthcare programs, curtailment or restructuring of our operations and agreements that materially restrict the manner in which a company promotes or distributes drug products. These false claims statutes include, but are not limited to, the federal civil False Claims Act, which allows any individual to bring a lawsuit against an individual or entity, including a pharmaceutical or biopharmaceutical company on behalf of the federal government alleging the knowing submission of false or fraudulent claims, or causing to present such false or fraudulent claims, for payment or approval by a federal program such as Medicare or Medicaid. These False Claims Act lawsuits against pharmaceutical and biopharmaceutical companies have increased significantly in number and breadth, leading to several substantial civil and criminal settlements regarding certain sales practices, including promoting off-label drug uses involving fines in excess of $1.0 billion. This growth in litigation has increased the risk that a pharmaceutical company will have to defend a false claim action, pay settlement fines or restitution, agree to comply with burdensome reporting and compliance obligations, and be excluded from participation in Medicare, Medicaid and other federal and state healthcare programs. If we, or any partner that we may engage, do not lawfully promote our approved products, we may become subject to such litigation, which have a material adverse effect on our business, financial condition and results of operations.

Our product candidates may cause undesirable side effects or have other properties that could delay or prevent their regulatory approval, limit the commercial scope of their approved use, or result in significant negative consequences following any marketing approval.

Undesirable side effects caused by our product candidates could cause the interruption, delay or halting of the trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other foreign regulatory authorities. In our Phase 2b clinical trial of entinostat in advanced HR+, HER2- breast cancer, the most significant adverse events were fatigue, gastrointestinal disturbances and hematologic toxicities, all of which occurred in higher numbers than in the placebo group. Results of the clinical trials may reveal a high and unacceptable severity and prevalence of side effects or other unexpected characteristics. In such event, the trials could be suspended or terminated, or the FDA or foreign regulatory authorities could deny approval of our product candidates for any or all targeted indications. Drug-related side effects could affect patient recruitment or the ability of enrolled subjects to complete the trial or result in potential product liability claims. Any of these occurrences may harm our business, financial condition and prospects.

Additionally, if our product candidates receive marketing approval, and we or others later identify undesirable side effects, a number of potentially significant negative consequences could result, including:

Any of these events could prevent us from achieving or maintaining market acceptance of our product candidates for use in targeted indications or otherwise materially harm its commercial prospects, if approved, and could harm our business, results of operations and prospects.

Our failure to obtain regulatory approval in international jurisdictions would prevent us from marketing our product candidates outside the United States.

In order to market and sell our product candidates in other jurisdictions, we must obtain separate marketing approvals for those jurisdictions and comply with their numerous and varying regulatory requirements. We may not obtain foreign regulatory approvals on a timely basis, or at all. The approval procedure varies among countries and can involve additional testing. The time required to obtain approval may differ substantially from that required to obtain FDA approval. The regulatory approval process outside the United States generally includes all of the risks associated with obtaining FDA approval. In addition, in many countries outside the United States, product reimbursement approvals must be secured before regulatory authorities will approve the product for sale in that country. Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our product candidates in certain countries. Further, clinical trials conducted in one country may not be accepted by regulatory authorities in other countries and regulatory approval in one country does not ensure approval in any other country, while a failure or delay in obtaining regulatory approval in one country may have a negative effect on the regulatory approval process in others. For example, based on scientific advice that we received from the European Medicines Agency in March 2014, the current Phase 3 clinical trial is likely to be insufficient to receive regulatory approval in Europe for entinostat to treat advanced HR+, HER2- breast cancer. Our failure to obtain approval of our product candidates by foreign regulatory authorities may negatively impact the commercial prospects of such product candidates and our business prospects could decline. Also, if regulatory approval for our product candidates is granted, it may be later withdrawn. If we fail to comply with the regulatory requirements in international jurisdictions and receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential for our product candidates will be harmed and our business may be adversely affected.

We face significant competition from other biotechnology and pharmaceutical companies, and our operating results will suffer if we fail to compete effectively.

Even if entinostat in combination with exemestane were approved for treatment of advanced HR+, HER2- breast cancer, it would face competition from other therapies recently approved for use in combination with hormone therapy in this population, including Ibrance, Kisqali, Afinitor, Verzenio, Piqray and other therapies under FDA review or currently in Phase 3 clinical development.

The pharmacologic treatment of NSCLC and melanoma patients has included chemotherapies and therapies targeting specific gene mutations. Over the past few years, immune checkpoint inhibitors have been approved for NSCLC and melanoma. Currently there are few approved combination immuno-oncology therapies although numerous drugs are undergoing active clinical investigation. We believe that if entinostat in combination with Keytruda were approved for the treatment of NSCLC or melanoma it would face competition from standard-of-care approaches and other investigational drugs being tested in combination with any of these approaches.

Chronic graft versus host disease has historically been managed by off-label treatments. However, in 2017 ibrutinib (Imbruvica®) became the first drug approved for use patients with cGVHD after failure of one or more lines of systemic therapy. KD-025 and Ruxolitinib (Jakafi®), are currently in registration-directed studies to treat steroid refractory cGVHD patients and, if approved, may also compete with axatilimab.

SNDX-5613 is being developed for the treatment of adult and pediatric patients with MLL-r ALL, AML and NPM1 mutant AML. At this time, there are no drugs approved for these defined populations and patients are managed using the standard of care treatment regimens developed for general AML and ALL populations. While there are other agents in early development for similar populations, SNDX-5613 has the potential to be the first defined therapy for patients with MLLr ALL, MLLr AML and/or NPM1 mutant AML.

Many of our existing or potential competitors have substantially greater financial, technical and human resources than we do and significantly greater experience in the discovery and development of product candidates, obtaining FDA and other regulatory approvals of products and the commercialization of those products. Our competitors may be more successful than us in obtaining FDA approval for drugs and achieving widespread market acceptance. Our competitors’ drugs may be more effective or more effectively marketed and sold than any drug we may commercialize and may render our product candidates obsolete or non-competitive before we can recover the expenses of developing and commercializing any of our product candidates. Our competitors may also obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours. We anticipate that we will face intense and increasing competition as new drugs enter the market and advanced technologies become available.

We believe that our ability to successfully compete will depend on, among other things:

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

Adverse events in the field of immuno-oncology could damage public perception of our product candidates and negatively affect our business.

The commercial success of our product candidates will depend in part on public acceptance of the use of cancer immunotherapies. Adverse events in clinical trials of our product candidates or in clinical trials of others developing similar products and the resulting publicity, as well as any other adverse events in the field of immuno-oncology that may occur in the future, could result in a decrease in demand for any products that we may develop. If public perception is influenced by claims that the use of cancer immunotherapies is unsafe, our product candidates may not be accepted by the general public or the medical community.

Future adverse events in immuno-oncology or the biopharmaceutical industry could also result in greater governmental regulation, stricter labeling requirements and potential regulatory delays in the testing or approvals of our products. Any increased scrutiny could delay or increase the costs of obtaining regulatory approval for our product candidates.

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

We are exposed to the risk that our employees, consultants, distributors, and collaborators may engage in fraudulent or illegal activity. Misconduct by these parties could include intentional, reckless or negligent conduct or disclosure of unauthorized activities to us that violates the regulations of the FDA and non-U.S. regulators, including those laws requiring the reporting of true, complete and accurate information to such regulators, manufacturing standards, healthcare fraud and abuse laws and regulations in the United States

and abroad or laws that require the true, complete and accurate reporting of financial information or data. In particular, sales, marketing and business arrangements in the healthcare industry, including the sale of pharmaceuticals, 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 pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. It is not always possible to identify and deter misconduct by our employees and other third parties, 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 result in the imposition of significant fines or other sanctions, including the imposition of civil, criminal and administrative penalties, damages, monetary fines, disgorgement, individual imprisonment, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, 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, contractual damages, reputational harm, diminished profits and future earnings and curtailment of operations, any of which could adversely affect our ability to operate our business and our results of operations. Whether or not we are successful in defending against such actions or investigations, we could incur substantial costs, including legal fees, and divert the attention of management in defending ourselves against any of these claims or investigations.

We must attract and retain additional highly skilled employees in order to succeed.

To succeed, we must recruit, retain, manage and motivate qualified clinical, scientific, technical and management personnel and we face significant competition for experienced personnel. If we do not succeed in attracting and retaining qualified personnel, particularly at the management level, it could adversely affect our ability to execute our business plan and harm our operating results. In particular, the loss of one or more of our executive officers could be detrimental to us if we cannot recruit suitable replacements in a timely manner. The competition for qualified personnel in the pharmaceutical industry is intense and as a result, we may be unable to continue to attract and retain qualified personnel necessary for the development of our business or to recruit suitable replacement personnel.

Many of the other pharmaceutical companies that we compete against for qualified personnel have greater financial and other resources, different risk profiles and a longer history in the industry than we do. They also may provide more diverse opportunities and better chances for career advancement. Some of these characteristics may be more appealing to high-quality candidates than what we have to offer. If we are unable to continue to attract and retain high-quality personnel, the rate and success at which we can discover and develop product candidates and our business will be limited.

Even if we commercialize our product candidates, they or any other product candidates that we develop, may become subject to unfavorable pricing regulations or third-party coverage or reimbursement practices, which could harm our business.

Our ability to successfully commercialize our existing product candidates, or any other product candidates that we develop, will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from third-party payors, including government healthcare programs, private health insurers, managed care plans and other organizations. Third-party payors determine which medications they will cover and establish reimbursement levels. Third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products.

We cannot be sure that coverage and reimbursement will be available for any product that we commercialize and, if reimbursement is available, what the level of reimbursement will be. Limitation on coverage and reimbursement may impact the demand for, or the price of, and our ability to successfully commercialize entinostat or any other product candidates that we develop.

There may be significant delays in obtaining coverage and reimbursement for newly approved drugs, and coverage may be more limited than the indications for which the drug is approved by the FDA or foreign regulatory authorities. Moreover, eligibility for coverage and reimbursement does not imply that a drug will be paid for in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution expenses. Interim reimbursement levels for new drugs, if applicable, may also not be sufficient to cover our costs and may only be temporary. Reimbursement rates may vary according to the use of the drug and the clinical setting in which it is used, may be based on reimbursement levels already set for lower cost drugs and may be incorporated into existing payments for other services. Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States.

Private payors often follow decisions by the Centers for Medicare & Medicaid Services, or CMS, regarding coverage and reimbursement to a substantial degree. However, one payor’s determination to provide coverage for a drug product does not assure that other payors will also provide coverage for the drug product. As a result, the coverage determination process is often a time-

consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. Our inability to promptly obtain coverage and adequate reimbursement rates from both government-funded and private payors for any approved products that we develop could have an adverse effect on our operating results, our ability to raise capital needed to commercialize products and our overall financial condition.

The regulations that govern marketing approvals, coverage and reimbursement for new drug products vary widely from country to country. Current and future 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 may obtain marketing approval for our product candidates in a particular country, but be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, which could negatively impact the revenues we generate from the sale of the product in that particular country. Adverse pricing limitations may hinder our ability to recoup our investment even if our product candidates obtain marketing approval.

There can be no assurance that our product candidates, if they are approved for sale in the United States or in other countries, will be considered medically reasonable and necessary for a specific indication, that it will be considered cost effective by third-party payors, that coverage and an adequate level of reimbursement will be available, or that third-party payors’ reimbursement policies will not adversely affect our ability to sell our product candidates profitably.

Current and future legislation may increase the difficulty and cost for us to commercialize our product candidates and affect the prices we may obtain.

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, restrict or regulate post-approval activities and affect our ability to profitably sell any product candidate for which we obtain marketing approval. For example, then President Obama signed into law the Affordable Care Act. Among other cost containment measures, the Affordable Care Act established an annual, nondeductible fee on any entity that manufactures or imports branded prescription drugs and biologic agents, a Medicare Part D coverage gap discount program, and a formula that increased the rebates a manufacturer must pay under the Medicaid Drug Rebate Program. There remain judicial and Congressional challenges, as well as recent efforts by the Trump administration to repeal or replace certain aspects of the Affordable Care Act. Since January 2017, President Trump has signed two Executive Orders designed to delay the implementation of certain provisions of the Affordable Care Act or otherwise circumvent some of the requirements for health insurance mandated by the Affordable Care Act. Concurrently, Congress has considered legislation that would repeal or repeal and replace all or part of the Affordable Care Act. While Congress has not passed comprehensive repeal legislation, several bills affecting the implementation of certain taxes under the Affordable Care Act have been signed into law. The Tax Cuts and Jobs Act of 2017 includes a provision repealing, effective January 1, 2019, the tax-based shared responsibility payment imposed by the Affordable Care Act on certain individuals who fail to maintain qualifying health coverage for all or part of a year that is commonly referred to as the “individual mandate.” Additionally, the 2020 federal spending package permanently eliminated, effective January 1, 2020, the Affordable Care Act’s mandated “Cadillac” tax on high-cost employer-sponsored health coverage and medical device tax and, effective January 1, 2021, also eliminates the health insurer tax. Further, the Bipartisan Budget Act of 2018, or the BBA, among other things, amended the Affordable Care Act, effective January 1, 2019, to increase from 50% to 70% the point-of-sale discount that is owed by pharmaceutical manufacturers who participate in Medicare Part D and to close the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole.” In December 2018, CMS published a final rule permitting further collections and payments to and from certain Affordable Care Act qualified health plans and health insurance issuers under its risk adjustment program in response to the outcome of federal district court litigation regarding the method CMS uses to determine this risk adjustment. On December 14, 2018, a Texas U.S. District Court Judge ruled that the Affordable Care Act is unconstitutional in its entirety because the “individual mandate” was repealed by the U.S. Congress as part of the Tax Cuts and Jobs Act of 2017 Act. Additionally, on December 18, 2019, the U.S. Court of Appeals for the 5th Circuit upheld the District Court ruling that the individual mandate was unconstitutional and remanded the case back to the District Court to determine whether the remaining provisions of the Affordable Care Act are invalid as well. On March 2, 2020, the United States Supreme Court granted the petitions for writs of certiorari to review this case and has allotted one hour for oral arguments. It is unclear when such oral arguments are to be held and when a decision is expected to be made. It is also unclear how such litigation, and other efforts to repeal and replace the Affordable Care Act will impact the Affordable Care, and our business. In addition, Congress may consider other legislation to repeal and replace elements of the Affordable Care Act.

Other legislative changes have been proposed and adopted since the Affordable Care Act was enacted. For example, in August 2011, then President Obama signed into law the Budget Control Act of 2011, which, among other things, created the Joint Select Committee on Deficit Reduction to recommend to Congress proposals in spending reductions. The Joint Select Committee on Deficit Reduction did not agree upon a targeted deficit reduction of at least $1.2 trillion for fiscal years 2012 through 2021, triggering the

Affordable Care Act’s automatic reduction to several government programs. This included aggregate reductions to Medicare payments to providers of up to 2% per fiscal year, effective as of 2013. Further legislation, including the BBA, has extended the 2% reduction to 2029. In January 2013, then President Obama signed into law the American Taxpayer Relief Act of 2012, which, among other things, reduced Medicare payments to several types of providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years.

Further, 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, review the relationship between pricing and manufacturer patient programs, reduce the cost of drugs under Medicare, and reform government program reimbursement methodologies for drugs. At the federal level, the Trump administration’s budget proposal for fiscal years 2021 includes a $135 billion allowance to support legislative proposals seeking to reduce drug prices, increase competition, lower out-of-pocket drug costs for patients, and increase patient access to lower-cost generic and biosimilar drugs. The Trump administration also released a “Blueprint” to lower drug prices and reduce out of pocket costs of drugs that contains additional proposals to increase manufacturer competition, increase the negotiating power of certain federal healthcare programs, incentivize manufacturers to lower the list price of their products and reduce the out of pocket costs of drug products paid by consumers. For example, May 2019, CMS issued a final rule to allow Medicare Advantage plans the option to use step therapy for part B drugs beginning January 1, 2020. This final rule codified CMS’s policy change that was effective January 1, 2019. While some of these and other measures may require additional authorization through additional legislation to become effective, Congress and the Trump administration have each indicated that it will continue to seek new legislative administrative and executive measures, including the President’s issuance of future executive orders, to control drug costs. At the state level, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.

We cannot predict the likelihood, nature or extent of government regulations that may arise from future legislation, administrative or executive action. We expect that the Affordable Care Act, as well as other current or future healthcare reform measures may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any approved product. This 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. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability or commercialize our products.

Product liability lawsuits against us could cause us to incur substantial liabilities and to limit commercialization of our product candidates.

We face an inherent risk of product liability exposure related to the testing of our product candidates in human trials and will face an even greater risk if we commercially sell any products that we may develop. Product liability claims may be brought against us by subjects enrolled in our trials, patients, healthcare providers or others using, administering or selling our products. If we cannot successfully defend ourselves against claims that our product candidates or other products that we may develop caused injuries, we could incur substantial liabilities. Regardless of merit or eventual outcome, liability claims may result in:

While we currently hold trial liability insurance coverage consistent with industry standards, this may not adequately cover all liabilities that we may incur. We also may not be able to maintain insurance coverage at a reasonable cost or in an amount adequate to satisfy any liability that may arise in the future. We intend to expand our insurance coverage for products to include the sale of commercial products if we obtain marketing approval for our product candidates, but we may be unable to obtain commercially reasonable product liability insurance. A successful product liability claim or series of claims brought against us, particularly if judgments exceed our insurance coverage, could decrease our cash and adversely affect our business and financial condition.

Our relationships with customers and third-party payors will be subject to applicable anti-kickback, fraud and abuse, transparency and other healthcare laws and regulations as well as privacy and data security laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm, fines, exclusion from participation in government healthcare programs, curtailments or restrictions of our operations, administrative burdens and diminished profits and future earnings.

Healthcare providers, physicians and third-party payors play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our current and future arrangements with physicians, third-party payors and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may constrain the business or financial arrangements and relationships through which we conduct clinical research and market, sell and distribute our products for which we obtain marketing approval. Restrictions under applicable federal and state healthcare laws and regulations, include, but are not limited to, the following:

Efforts to ensure that our business arrangements with third parties and our business generally, will comply with applicable healthcare laws and regulations will involve substantial costs. It is possible that governmental 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 our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment, exclusion from government funded healthcare programs, such as Medicare and Medicaid, contractual damages, reputational harm, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, and the curtailment or restructuring of our operations. Defending against any such actions can be costly, time-consuming and may require significant financial and personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired. Further, if any physician or other healthcare provider or entity 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.

Significant disruptions of our information technology systems or data security incidents could result in significant financial, legal, regulatory, business and reputational harm to us.

We are increasingly dependent on information technology systems and infrastructure, including mobile technologies, to operate our business. In the ordinary course of our business, we collect, store, process and transmit large amounts of sensitive information, including intellectual property, proprietary business information, personal information and other confidential information. It is critical that we do so in a secure manner to maintain the confidentiality, integrity and availability of such sensitive information. We have also outsourced elements of our operations (including elements of our information technology infrastructure) to third parties, and as a result, we manage a number of third-party vendors who may or could have access to our computer networks, our confidential information or the confidential information of third parties that is in our possession. In addition, those third party vendors may in turn subcontract or outsource some of their responsibilities to other parties. While all information technology operations are inherently vulnerable to inadvertent or intentional security breaches, incidents, attacks and exposures, the accessibility and distributed nature of our information technology systems, and the sensitive information stored on those systems, make such systems potentially vulnerable to unintentional or malicious, internal and external attacks on our technology environment. In addition, due to the COVID-19 pandemic, we have enabled substantially all of our employees to work remotely, which may make us more vulnerable to cyberattacks. Potential vulnerabilities can be exploited from inadvertent or intentional actions of our employees, third-party vendors, business partners, or by malicious third parties. Attacks of this nature are increasing in their frequency, levels of persistence, sophistication and intensity, and are being conducted by sophisticated and organized groups and individuals with a wide range of motives (including, but not limited to, industrial espionage) and expertise, including organized criminal groups, “hacktivists,” nation states and others. In addition to the extraction of sensitive information, such attacks could include the deployment of harmful malware, ransomware, denial-of-service attacks, social engineering and other means to affect service reliability and threaten the confidentiality, integrity and availability of information. The prevalent use of mobile devices further increases the risk of data security incidents.

Significant disruptions of our, our third-party vendors’ and/or business partners’ information technology systems or other similar data security incidents could adversely affect our business operations and/or result in the loss, misappropriation and/or unauthorized access, use or disclosure of, or the prevention of access to, sensitive information, which could result in financial, legal, regulatory, business and reputational harm to us. In addition, information technology system disruptions, whether from attacks on our technology environment or from computer viruses, natural disasters, terrorism, war and telecommunication and electrical failures, could result in a material disruption of our development programs and our business operations. 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.

There is no way of knowing with certainty whether we have experienced any data security incidents that have not been discovered. While we have no reason to believe this to be the case, attackers have become very sophisticated in the ways that they conceal access to systems. Many companies that have been attacked are not aware that they have been attacked. Any event that leads to unauthorized access, use or disclosure of personal information, including but not limited to personal information regarding employees or clinical trial patients, could disrupt our business, harm our reputation, compel us to comply with applicable federal and/or state breach notification laws and foreign law equivalents, subject us to time consuming, distracting and expensive litigation, regulatory investigation and oversight, mandatory corrective action, require us to verify the correctness of database contents, or otherwise subject us to liability under laws, regulations and contractual obligations, including those that protect the privacy and security of personal information. This could result in increased costs to us, and result in significant legal and financial exposure and/or reputational harm. Any failure or perceived failure by us or our vendors or business partners to comply with our privacy, confidentiality or data security-related legal or other obligations to third parties, or any further security incidents or other inappropriate access events resulting in the unauthorized access, release or transfer of sensitive information, which could include personally identifiable information, may result in governmental investigations, enforcement actions, regulatory fines, litigation, or public statements against us by advocacy groups or others, and could cause third parties, including clinical sites, regulators or current and

potential partners, to lose trust in us or we could be subject to claims by third parties that we have breached our privacy- or confidentiality-related obligations, which could materially and adversely affect our business and prospects. Moreover, data security incidents and other inappropriate access can be difficult to detect. Any delay in identifying them may lead to increased harm of the type described above. While we have implemented security measures to protect our information technology systems and infrastructure, there can be no assurance that such measures will successfully prevent service interruptions or security incidents. Further, because of the work-from-home policies we implemented due to COVID-19, information that is normally protected, including company confidential information, may be less secure.

We have incurred net losses since our inception and anticipate that we will continue to incur net losses for the foreseeable future.

Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate efficacy or an acceptable safety profile, gain regulatory approval or be commercially viable. We are a clinical stage biopharmaceutical company with limited operating history. We have no products approved for commercial sale and have not generated any product revenues to date, and we continue to incur significant research and development and other expenses related to our ongoing operations and clinical development of entinostat. As a result, we are not and have never been profitable and have incurred losses in each period since our inception in 2005.

For the quarter ended March 31, 2020, we reported a net loss of $15.2 million. Net loss attributable to shareholders for the quarter ended March 31, 2020, was $19.3 million. As of March 31, 2020, we had an accumulated deficit of $510.7 million, which included non-cash charges for stock-based compensation, preferred stock accretion and extinguishment charges. We expect to continue to incur significant losses for the foreseeable future, and we expect these losses to increase as we continue our pre-commercialization activities for, and our research and development of, and seek regulatory approvals for, our product candidates. We may also encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenues, if any. Our prior losses and expected future losses have had and will continue to have an adverse effect on our stockholders’ equity and working capital.

We currently have no source of product revenue and may never achieve or maintain profitability.

Our ability to generate product revenue and become profitable depends upon our ability to successfully commercialize our product candidates. We do not anticipate generating revenue from the sale of our product candidates for the foreseeable future. Our ability to generate future product revenue also depends on a number of additional factors, including, but not limited to, our ability to:

In addition, because of the numerous risks and uncertainties associated with drug development, we are unable to predict the timing or amount of increased expenses, and if or when we will achieve or maintain profitability. In addition, our expenses could increase beyond expectations if we decide to or are required by the FDA or foreign regulatory authorities to perform studies or trials in addition to those that we currently anticipate. Even if we complete the development and regulatory processes described above, we anticipate incurring significant costs associated with launching and commercializing our current product candidates and any other product candidates we may develop.

Even if we generate revenues from the sale of our product candidates, we may not become profitable and may need to obtain additional funding to continue operations or acquire additional products that will require additional funding to develop them. If we fail to become profitable or do not sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce our operations or even shut down.

We will require additional capital to finance our planned operations, which may not be available to us on acceptable terms, or at all. As a result, we may not complete the development and commercialization of, or obtain regulatory approval for our existing product candidates or develop new product candidates.

Our operations have consumed substantial amounts of cash since our inception, primarily due to our research and development efforts. We expect our research and development expenses to increase substantially in connection with our ongoing and planned activities. We believe that our existing cash, cash equivalents and short-term investments will fund our projected operating expenses and capital expenditure requirements for at least the next 12 months. Unexpected circumstances may cause us to consume capital more rapidly than we currently anticipate, including as a result of the COVID-19 pandemic. For example, we may discover that we need to conduct additional activities that exceed our current budget to achieve appropriate rates of patient enrollment, which would increase our development costs.

In any event, we will require additional capital to continue the development of, obtain regulatory approval for, and to commercialize our existing product candidates and any future product candidates. Any efforts to secure additional financing may divert our management from our day-to-day activities, which may adversely affect our ability to develop and commercialize our product candidates. The COVID-19 pandemic has already resulted in a significant disruption of global financial markets. If the disruption persists and deepens, we could experience an inability to access additional capital. We cannot guarantee that future financing will be available in sufficient amounts or on terms acceptable to us, if at all. If we do not raise additional capital when required or on acceptable terms, we may need to:

If we need to conduct additional fundraising activities and we do not raise additional capital in sufficient amounts or on terms acceptable to us, we may be unable to pursue development and commercialization efforts, which will harm our business, operating results and prospects.

Our future funding requirements, both short- and long-term, will depend on many factors, including:

If we cannot expand our operations or otherwise capitalize on our business opportunities because we cannot secure sufficient capital, our business, financial condition and results of operations could be materially adversely affected.

The terms of our loan and security agreements place restrictions on our operating and financial flexibility. If we raise additional capital through debt financing, the terms of any new debt could further restrict our ability to operate our business.

Our loan and security agreement, or the Loan Agreement, with Hercules Capital, Inc., or Hercules, for aggregate maximum borrowings of up to $30.0 million, or the Credit Facility, is collateralized by substantially all of our and our subsidiaries personal property and other assets, other than our intellectual property. As of March 1, 2020, the outstanding principal balance under the Credit Facility was $20.0 million, resulting from the closing of the first tranche of funding which occurred on February 7, 2020. The Credit Facility contains customary representations, warranties, affirmative and negative covenants and events of default applicable to us and our subsidiaries.

If we default under the Credit Facility, Hercules may accelerate all of our repayment obligations and exercise all of their rights and remedies under the Credit Facility and applicable law, potentially requiring us to renegotiate our agreement on terms less favorable to us. Further, if we are liquidated, the lenders’ right to repayment would be senior to the rights of the holders of our common stock to receive any proceeds from the liquidation. Hercules could declare a default upon the occurrence of any event, among others, that they interpret as a material adverse effect or a change of control as delineated under the Credit Facility, payment defaults, or breaches of covenants thereby requiring us to repay the loan immediately or to attempt to reverse the declaration of default through negotiation or litigation. Any declaration by the lender of an event of default could significantly harm our business and prospects and could cause the price of our common stock to decline. If we raise any additional debt financing, the terms of such additional debt could further restrict our operating and financial flexibility.

Changes in tax laws or regulations could materially adversely affect our company.

New tax laws or regulations could be enacted at any time, and existing tax laws or regulations could be interpreted, modified or applied in a manner that is adverse to us, which could adversely affect our business and financial condition. For example, legislation enacted in 2017, informally titled the Tax Cuts and Jobs Act, or the Tax Act, enacted many significant changes to the U.S. tax laws, including changes in corporate tax rates, the utilization of our NOLs and other deferred tax assets, the deductibility of expenses, and the taxation of foreign earnings. Future guidance from the Internal Revenue Service and other tax authorities with respect to the Tax Act may affect us, and certain aspects of the Tax Act could be repealed or modified in future legislation. For example, the Coronavirus Aid, Relief and Economic Security Act, or the CARES Act, modified certain provisions of the Tax Act. In addition, it is uncertain if and to what extent various states will conform to the Tax Act, the CARES Act, or any newly enacted federal tax legislation. The impact of changes under the Tax Act, the CARES Act, or future reform legislation could increase our future U.S. tax expense and could have a material adverse impact on our business and financial condition.

Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

We have incurred substantial losses during our history. We do not expect to become profitable in the near future, and we may never achieve profitability. Unused losses generally are available to be carried forward to offset future taxable income, if any. Under Sections 382 and 383 of the Code if a corporation undergoes an “ownership change,” generally defined as a greater than 50% 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, or NOLs, and other pre-change tax attributes (such as research tax credits) to offset its post-change taxable income or taxes may be limited. We completed an analysis through March 31, 2020 and determined that on March 30, 2007 and August 21, 2015 ownership changes had occurred. We may have experienced an ownership change since March 31, 2020, and we may also experience ownership changes in the future as a result of shifts in our stock ownership, some of which may be outside of our control. As a result, our ability to use our pre-change NOLs to offset U.S. federal taxable income may be subject to limitations, which could potentially result in increased future tax liability to us. In addition, at the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed.

If we are unable to obtain or protect intellectual property rights, we may not be able to compete effectively in our market.

Our success depends in significant part on our and our licensors’ and licensees’ ability to establish, maintain and protect patents and other intellectual property rights and operate without infringing the intellectual property rights of others. We have filed patent applications both in the United States and in foreign jurisdictions to obtain patent rights to inventions we have discovered. We have also licensed from third parties rights to patent portfolios. Some of these licenses give us the right to prepare, file and prosecute patent applications and maintain and enforce patents we have licensed, and other licenses may not give us such rights.

The patent prosecution process is expensive and time-consuming, and we and our current or future licensors and licensees may not be able to prepare, file and prosecute all necessary or desirable patent applications at a reasonable cost or in a timely manner. It is also possible that we or our licensors or licensees will fail to identify patentable aspects of inventions made in the course of development and commercialization activities before it is too late to obtain patent protection on them. Moreover, 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 or license to third parties and are reliant on our licensors or licensees. Therefore, these patents and applications may not be prosecuted and enforced in a manner consistent with the best interests of our business. If our current or future licensors or licensees fail to establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If our licensors or licensees are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised.

The patent position of biotechnology and pharmaceutical companies generally is highly uncertain, involves complex legal and factual questions and has in recent years been the subject of much litigation. As a result, the issuance, scope, validity, enforceability and commercial value of our and our current or future licensors’ or licensees’ patent rights are highly uncertain. Our and our licensors’ or licensees’ pending and future patent applications may not result in patents being issued which protect our technology or products, in whole or in part, or which effectively prevent others from commercializing competitive technologies and products. The patent examination process may require us or our licensors or licensees to narrow the scope of the claims of our or our licensors’ or licensees’ pending and future patent applications, which may limit the scope of patent protection that may be obtained. It is possible that third parties with products that are very similar to ours will circumvent our or our licensors’ or licensees’ patents by means of alternate designs or processes. We cannot be certain that we are the first to invent the inventions covered by pending patent applications and, if we are not, we may be subject to priority disputes. We may be required to disclaim part or all of the term of certain patents or all of the term of certain patent applications. There may be prior art of which we are not aware that may affect the validity or enforceability of a patent claim. There also may be prior art of which we are aware, but which we do not believe affects the validity or enforceability of a claim, which may, nonetheless, ultimately be found to affect the validity or enforceability of a claim. No assurance can be given that if challenged, our patents would be declared by a court to be valid or enforceable or that even if found valid and enforceable, a competitor’s technology or product would be found by a court to infringe our patents. We may analyze patents or patent applications of our competitors that we believe are relevant to our activities, and consider that we are free to operate in relation to our product candidate, but our competitors may achieve issued claims, including in patents we consider to be unrelated, which block our efforts or may potentially result in our product candidate or our activities infringing such claims. The possibility exists that others will develop products which have the same effect as our products on an independent basis which do not infringe our patents or other intellectual property rights, or will design around the claims of patents that we have had issued that cover our products. Our and our licensors’ or licensees’ patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless and until a patent issues from such applications, and then only to the extent the issued claims cover the technology.

Furthermore, given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours. Entinostat composition of matter U.S. Patent RE39,754, which we licensed from Bayer, covers the chemical entity of entinostat and any crystalline or non-crystalline form of entinostat and expired in September 2017.

The portfolio we licensed from Bayer also includes U.S. Patent 7,973,166, or the ‘166 patent, which covers a crystalline polymorph of entinostat which is referred to as crystalline polymorph B, the crystalline polymorph used in the clinical development of entinostat. Many compounds can exist in different crystalline forms. A compound which in the solid state may exhibit multiple different crystalline forms is called polymorphic, and each crystalline form of the same chemical compound is termed a polymorph. A new crystalline form of a compound may arise, for example, due to a change in the chemical process or the introduction of an impurity. Such new crystalline forms may be patented. The ‘166 patent expires in 2029. On March 7, 2014, our licensor Bayer applied for reissue of the ‘166 patent. The reissue application seeks to add three inventors not originally listed on the ‘166 patent. The reissue application does not seek to amend the claims issued in the ‘166 patent. On April 28, 2015, the USPTO re-issued the ‘166 patent as U.S. patent RE45,499. RE45,499 reissued with the same claims originally issued in the ‘166 patent and the list of inventors on RE45,499 now lists the additional three inventors that were not included on the ‘166 patent. The ‘166 patent has now been surrendered

in favor of RE45,499. RE45,499 has the same term as the initial term of the ‘166 patent, which expires in August 2029. After expiry of RE39,754, which occurred in September 2017, a competitor may develop a competing polymorphic form other than based on polymorph B, which could compete with polymorph B.

In spite of our efforts and efforts of our licensor, we may not be successful in defending the validity of the claims of the RE45,499 reissue patent or any of its foreign counterparts. If the claims of the ‘166 patent or any of its counterparts are found to be invalid by a competent court, we may not be able to effectively block entry of generic versions of our entinostat crystalline polymorph B candidate products into markets where the crystalline polymorph B patent claims are found to be invalid. Additionally, even if we submit an NDA before the expiration of U.S. Patent RE45,499 and are successful in obtaining an extension of the term of U.S. Patent RE45,499 based on FDA regulatory delays, such extension will only extend the term of RE45,499 for a few additional years (up to a maximum of five additional years for patent claims covering a new chemical entity).

The portfolio that we licensed from UCB includes patent applications with pending claims directed to the composition of matter of axatilimab (a humanized, full-length IgG4 (kappa light chain) antibody with high affinity for the CSF-1R) as well as claims directed to methods of use of axatilimab. There is no guarantee that any patents will be granted based on the pending applications we licensed from UCB or even if one or more patents are granted that the claims issued in those patents would cover axatilimab or methods of using axatilimab. Based on the priority date and filing date of the applications in the portfolio we licensed from UCB, we expect that a patent, if any, granted based on the currently pending applications would expire in 2034. The actual term of any patents granted based on the pending applications we licensed from UCB can only be determined after such patents are actually granted.

The portfolio that we licensed from Vitae Pharmaceuticals, a subsidiary of Allergan, includes patent applications with pending claims directed to inhibitors of the interaction of menin with MLL and MLL fusion proteins, pharmaceutical compositions containing the same, and their use in the treatment of cancer and other diseases mediated by the menin-MLL interaction. There is no guarantee that any patents will be granted based on the pending applications that we licensed from Allergan or even if one or more patents are granted that the claims issued in those patents would cover the desired lead compounds, compositions, and methods of use thereof. Based on the priority date and filing date of the applications in the portfolio that we licensed from Allergan, we expect that a patent, if any, granted based on the currently pending applications would expire in 2037. The actual term of any patents granted based on the pending applications that we licensed from Allergan can only be determined after such patents are actually granted.

We may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting, enforcing and defending patents on product candidates in all countries throughout the world is prohibitively expensive, and our or our licensors’ intellectual property rights in some countries outside the United States can be less extensive than those in the United States. 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. Consequently, we and our licensors may not be able to prevent third parties from practicing our and our licensors’ inventions in countries outside the United States, or from selling or importing products made using our and our licensors’ inventions in and into the United States or other jurisdictions. Competitors may use our and our licensors’ technologies in jurisdictions where we have not obtained patent protection to develop their own products and may export otherwise infringing products to territories where we and our licensors 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 and our licensors’ 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 and other intellectual property protection, particularly those relating to biopharmaceuticals, which could make it difficult for us and our licensors to stop the infringement of our and our licensors’ patents or marketing of competing products in violation of our and our licensors’ proprietary rights generally. Proceedings to enforce our and our licensors’ patent rights in foreign jurisdictions could result in substantial costs and divert our attention from other aspects of our business, could put our and our licensors’ patents at risk of being invalidated or interpreted narrowly and our and our licensors’ patent applications at risk of not issuing and could provoke third parties to assert claims against us or our licensors. We or our licensors may not prevail in any lawsuits that we or our licensors initiate and the damages or other remedies awarded, if any, may not be commercially meaningful.

The requirements for patentability may differ in certain countries, particularly developing countries. For example, unlike other countries, China has a heightened requirement for patentability, and specifically requires a detailed description of medical uses of a claimed drug. In India, unlike the United States, there is no link between regulatory approval of a drug and its patent status. Furthermore, generic drug manufacturers or other competitors may challenge the scope, validity or enforceability of our or our licensors’ patents, requiring us or our licensors to engage in complex, lengthy and costly litigation or other proceedings. Generic drug manufacturers may develop, seek approval for, and launch generic versions of our products. In addition to India, certain countries in Europe and developing countries, including China, have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In those countries, we and our licensors may have limited remedies if patents are infringed or if we or our licensors are compelled to grant a license to a third party, which could materially diminish the value of those patents. This could

limit our potential revenue opportunities. Accordingly, our and our licensors’ efforts to enforce intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we own or license.

If we breach our license agreement with Bayer related to entinostat or if the license agreement is otherwise terminated, we could lose the ability to continue the development and commercialization of entinostat.

Our commercial success depends upon our ability to develop, manufacture, market and sell entinostat. In March 2007, we entered into a license, development and commercialization agreement, or the Bayer license agreement, with Bayer pursuant to which we obtained a worldwide, exclusive license to develop and commercialize entinostat and any other products containing the same active ingredient. The Bayer license agreement, as amended, permits us to use entinostat or other licensed products under the Bayer license agreement for the treatment of any human disease, and we are obligated to use commercially reasonable efforts to develop, manufacture and commercialize licensed products for all commercially reasonable indications.

We are obligated to pay Bayer up to approximately $50 million in the aggregate upon obtaining certain milestones in the development and marketing approval of entinostat, assuming that we pursue at least two different indications for entinostat or any other licensed product under the Bayer license agreement. We are also obligated to pay Bayer up to $100 million in aggregate sales milestones, and a tiered, single-digit royalty on net sales by us, our affiliates and sublicensees of entinostat and any other licensed products under the Bayer license agreement. We are obligated to pay Bayer these royalties on a country-by-country basis for the life of the relevant licensed patents covering such product or 15 years after the first commercial sale of such product in such country, whichever is longer. We cannot determine the date on which our royalty payment obligations to Bayer would expire because no commercial sales of entinostat have occurred and the last-to-expire relevant patent covering entinostat in a given country may change in the future.

The Bayer license agreement will remain in effect until the expiration of our royalty obligations under the agreement in all countries. Either party may terminate the Bayer license agreement in its entirety or with respect to certain countries in the event of an uncured material breach by the other party. Either party may terminate the Bayer license agreement if voluntary or involuntary bankruptcy proceedings are instituted against the other party, if the other party makes an assignment for the benefit of creditors, or upon the occurrence of other specific events relating to the insolvency or dissolution of the other party. Bayer may terminate the Bayer license agreement if we seek to revoke or challenge the validity of any patent licensed to us by Bayer under the Bayer license agreement or if we procure or assist a third party to take any such action.

If the Bayer license agreement is terminated, we would not be able to develop, manufacture, market or sell entinostat and would need to negotiate a new or reinstated agreement, which may not be available to us on equally favorable terms, or at all.

If we breach the UCB license agreement related to axatilimab or if the UCB license agreement is otherwise terminated, we could lose the ability to continue the development and commercialization of axatilimab.

Our commercial success depends upon our ability to develop, manufacture, market and sell axatilimab. Subject to the achievement of certain milestone events, we may be required to pay UCB up to $119.5 million in one-time development and regulatory milestone payments over the term of the UCB license agreement. If we or any of our affiliates or sublicensees commercializes axatilimab, we will also be obligated to pay UCB low double-digit royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $250 million in potential one-time sales-based milestone payments based on achievement of certain annual sales thresholds. Under certain circumstances, we may be required to share a percentage of non-royalty income from sublicensees, subject to certain deductions, with UCB.

Either party may terminate the UCB license agreement in its entirety or with respect to certain countries in the event of an uncured material breach by the other party. Either party may terminate the UCB license agreement if voluntary or involuntary bankruptcy proceedings are instituted against the other party, if the other party makes an assignment for the benefit of creditors, or upon the occurrence of other specific events relating to the insolvency or dissolution of the other party. UCB may terminate the UCB license agreement if we seek to revoke or challenge the validity of any patent licensed to us by UCB under the UCB license agreement or if we procure or assist a third party to take any such action.

Unless terminated earlier in accordance with its terms, the UCB license agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country. We cannot determine the date on which our royalty payment obligations to UCB would expire because no commercial sales of axatilimab have occurred and the last-to-expire relevant patent covering axatilimab in a given country may change in the future.

If the UCB license agreement is terminated, we would not be able to develop, manufacture, market or sell axatilimab and would need to negotiate a new or reinstated agreement, which may not be available to us on equally favorable terms, or at all.

If we breach the license agreement related to SNDX-5613 or if the license agreement is otherwise terminated, we could lose the ability to continue the development and commercialization of SNDX-5613.

Our commercial success depends upon our ability to develop, manufacture, market and sell SNDX-5613. Subject to the achievement of certain milestone events, we may be required to pay Vitae, a subsidiary of Allergan, up to $99 million in one-time development and regulatory milestone payments over the term of the Allergan license agreement. In the event that we or any of our affiliates or sublicensees commercializes SNDX-5613, we will also be obligated to pay Allergan low single to low double-digit royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $70 million in potential one-time sales-based milestone payments based on achievement of certain annual sales thresholds. Under certain circumstances, we may be required to share a percentage of non-royalty income from sublicensees, subject to certain deductions, with Allergan.

Either party may terminate the license agreement in its entirety or with respect to certain countries in the event of an uncured material breach by the other party. Either party may terminate the license agreement if voluntary or involuntary bankruptcy proceedings are instituted against the other party, if the other party makes an assignment for the benefit of creditors, or upon the occurrence of other specific events relating to the insolvency or dissolution of the other party. Allergan may terminate the license agreement if we seek to revoke or challenge the validity of any patent licensed to us by Allergan under the license agreement or if we procure or assist a third party to take any such action.

Unless terminated earlier in accordance with its terms, the license agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country. We cannot determine the date on which our royalty payment obligations to Allergan would expire because no commercial sales of SNDX-5613 have occurred and the last-to-expire relevant patent covering SNDX-5613 in a given country may change in the future.

If the license agreement is terminated, we would not be able to develop, manufacture, market or sell SNDX-5613 and would need to negotiate a new or reinstated agreement, which may not be available to us on equally favorable terms, or at all.

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

As is the case with other biotechnology and pharmaceutical companies, our success is heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biopharmaceutical industry involve technological and legal complexity, and obtaining and enforcing biopharmaceutical patents is costly, time-consuming, and inherently uncertain. The Supreme Court has ruled on several patent cases in recent years, either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. In addition to increasing uncertainty with regard to our and our licensors’ ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on decisions by Congress, the federal courts, and the U.S. Patent and Trademark Office, or USPTO, the laws and regulations governing patents could change in unpredictable ways that may weaken our and our licensors’ ability to obtain new patents or to enforce existing patents and patents we and our licensors or collaborators may obtain in the future. In view of recent developments in U.S. patent laws, in spite of our efforts and the efforts of our licensors, we may face difficulties in obtaining allowance of our biomarker based patient selection patent claims or if we are successful in obtaining allowance of our biomarker based patient selection claims, we or our licensor may be unsuccessful in defending the validity of such claims if challenged before a competent court.

Recent patent reform legislation could increase the uncertainties and costs surrounding the prosecution of our and our licensors’ patent applications and the enforcement or defense of our or our licensors’ issued patents. On September 16, 2011, the Leahy-Smith America Invents Act, or the America Invents Act, was signed into law. The America Invents Act includes a number of significant changes to U.S. patent law. These include provisions that affect the way patent applications are prosecuted and may also affect patent litigation. The USPTO recently developed new regulations and procedures to govern administration of the American Invents Act, and many of the substantive changes to patent law associated with the America Invents 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 America Invents Act will have on the operation of our business. However, the America Invents Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our or our licensors’ patent applications and the enforcement or defense of our or our licensors’ issued patents, all of which could harm our business and financial condition.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance and annuity fees on any issued patent are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patent. The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of a patent or patent application include failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If we or our licensors fail to maintain the patents and patent applications covering our product candidates, our competitors might be able to enter the market, which would harm our business.

We may become involved in lawsuits to protect or enforce our intellectual property, which could be expensive, time-consuming and unsuccessful and have an adverse effect on the success of our business and on our stock price.

Third parties may infringe our or our licensors’ patents or misappropriate or otherwise violate our or our licensors’ intellectual property rights. In the future, we or our licensors may initiate legal proceedings to enforce or defend our or our licensors’ intellectual property rights, to protect our or our licensors’ trade secrets or to determine the validity or scope of intellectual property rights we own or control. Also, third parties may initiate legal proceedings against us or our licensors to challenge the validity or scope of intellectual property rights we own or control. The proceedings can be expensive and time-consuming and many of our or our licensors’ adversaries in these proceedings may have the ability to dedicate substantially greater resources to prosecuting these legal actions than we or our licensors can. Accordingly, despite our or our licensors’ efforts, we or our licensors may not be able to prevent third parties from infringing upon or misappropriating intellectual property rights we own or control, particularly in countries where the laws may not protect our rights as fully as in the United States. Litigation could result in substantial costs and diversion of management resources, which could harm our business and financial results. In addition, in an infringement proceeding, a court may decide that a patent owned by or licensed to us is invalid or unenforceable, or may refuse to stop the other party from using the technology at issue on the grounds that our or our licensors’ patents do not cover the technology in question. An adverse result in any litigation proceeding could put one or more of our or our licensors’ patents at risk of being invalidated, held unenforceable or interpreted narrowly.

Third-party preissuance submission of prior art to the USPTO, or opposition, derivation, reexamination, inter partes review or interference proceedings, or other preissuance or post-grant proceedings in the United States or other jurisdictions provoked by third parties or brought by us or our licensors or collaborators may be necessary to determine the priority of inventions with respect to our or our licensors’ patents or patent applications. An unfavorable outcome could require us or our licensors to cease using the related technology and commercializing our product candidates, or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us or our licensors a license on commercially reasonable terms or at all. Even if we or our licensors obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us or our licensors. In addition, if the breadth or strength of protection provided by our or our licensors’ patents and patent applications is threatened, it could dissuade companies from collaborating with us to license, develop or commercialize current or future product candidates. Even if we successfully defend such litigation or proceeding, we may incur substantial costs and it may distract our management and other employees. We could be found liable for monetary damages, including treble damages and attorneys’ fees, if we are found to have willfully infringed a patent.

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this process. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could have a downward effect on the price of shares of our common stock.

Third parties may initiate legal proceedings against us alleging that we infringe their intellectual property rights or we may initiate legal proceedings against third parties to challenge the validity or scope of intellectual property rights controlled by third parties, the outcome of which would be uncertain and could have an adverse effect on the success of our business.

Third parties may initiate legal proceedings against us or our licensors or collaborators alleging that we or our licensors or collaborators infringe their intellectual property rights or we or our licensors or collaborators may initiate legal proceedings against third parties to challenge the validity or scope of intellectual property rights controlled by third parties, including in oppositions, interferences, reexaminations, inter partes reviews or derivation proceedings before the United States or other jurisdictions. These proceedings can be expensive and time-consuming and many of our or our licensors’ adversaries in these proceedings may have the ability to dedicate substantially greater resources to prosecuting these legal actions than we or our licensors or collaborators can.

An unfavorable outcome could require us or our licensors or collaborators to cease using the related technology or developing or commercializing our product candidates, or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us or our licensors or collaborators a license on commercially reasonable terms or at all. Even if we or our licensors or collaborators obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us or our licensors or collaborators. In addition, we could be found liable for monetary damages, including treble damages and attorneys’ fees, if we are found to have willfully infringed a patent. A finding of infringement could prevent us from commercializing our product candidates or force us to cease some of our business operations, which could materially harm our business.

We may be subject to claims by third parties asserting that we or our employees have misappropriated their intellectual property, or claiming ownership of what we regard as our own intellectual property.

Many of our employees, including our senior management, were previously employed at universities or at other biotechnology or pharmaceutical companies, including our competitors or potential competitors. Some of these employees executed proprietary rights, non-disclosure and non-competition agreements in connection with such previous employment. Although we try to ensure that our employees do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or these employees have used or disclosed confidential information or intellectual property, including trade secrets or other proprietary information, of any such employee’s former employer. Litigation may be necessary to defend against these claims.

In addition, for some of our in-licensed patents and patent applications, we do not have access to every patent assignments or employee agreements demonstrating that all inventors have assigned their rights to the inventions or related patents. As a result, we may be subject to claims of ownership by such inventors.

If we fail in prosecuting or defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel or sustain damages. Such intellectual property rights could be awarded to a third party, and we could be required to obtain a license from such third party to commercialize our technology or products. Such a license may not be available on commercially reasonable terms or at all. Even if we successfully prosecute or defend against such claims, litigation could result in substantial costs and distract management.

Our inability to protect our confidential information and trade secrets would harm our business and competitive position.

In addition to seeking patents for some of our technology and products, we also rely on trade secrets, including unpatented know-how, technology and other proprietary information, to maintain our competitive position. We seek to protect these trade secrets, in part, by entering into non-disclosure and confidentiality agreements with parties who have access to them, such as our employees, corporate collaborators, outside scientific collaborators, third-party manufacturers, consultants, advisors and other third parties. We also enter into confidentiality and invention or patent assignment agreements with our employees and consultants. Despite these efforts, any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts both within and outside the United States may be less willing or unwilling to protect trade secrets. If a competitor lawfully obtained or independently developed any of our trade secrets, we would have no right to prevent such competitor from using that technology or information to compete with us, which could harm our competitive position.

The market price of our stock may be volatile and you could lose all or part of your investment.

The trading price of our common stock is highly volatile and subject to wide fluctuations in response to various factors, some of which we cannot control. In addition to the factors discussed in this “Risk Factors” section and elsewhere in this report, these factors include:

In addition, the stock market in general, and the Nasdaq Global Select Market and biopharmaceutical companies in particular, frequently experiences extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of such companies, including very recently in connection with the ongoing COVID-19 pandemic, which has resulted in decreased stock prices for many companies notwithstanding the lack of a fundamental change in their underlying business models or prospects. Broad market and industry factors, including potentially worsening economic conditions and other adverse effects or developments relating to the ongoing COVID-19 pandemic, may negatively affect the market price of our common stock, regardless of our actual operating performance. The realization of any of the above risks or any of a broad range of other risks, including those described in this “Risk Factors” section, could have a dramatic and negative impact on the market price of our common stock.

We may sell additional equity or debt securities or enter into other arrangements to fund our operations, which may result in dilution to our stockholders and impose restrictions or limitations on our business.

Until we can generate a sufficient amount of revenue from our products, if ever, we expect to finance future cash needs through public or private equity or debt offerings. If we raise additional funds through the issuance of additional equity or debt securities, it may result in dilution to our existing stockholders and/or increased fixed payment obligations. In August 2019, we filed a shelf registration statement on Form S-3 (Registration No. 333-233564) that allows us to sell up to an aggregate of $300 million of our common stock, which includes up to $50.0 million designated for an at-the-market offering program. As of March 31, 2020, $50.0 million of common stock remained available for sale under the at-the-market offering program. Further, in May 2020, we sold 5,555,556 shares of our common stock at a price per share of $18.00 with net proceeds of approximately $93.7 million. In January 2020, we sold 3,036,719 shares of our common stock at a price per share of $8.00 and pre-funded warrants to purchase 1,338,287 shares of our common stock for gross proceeds of approximately $35.0 million. Upon the completion of the January 2020 offering, we had 5,838,287 pre-funded warrant shares outstanding. The pre-funded warrants are exercisable into shares of common stock for $0.0001 per share. The shares of common stock into which the warrants may be exercised are considered outstanding for the purposes of computing earnings per share. We also have two outstanding series of warrants, Series 1 warrants and Series 2 warrants. As of March 31, 2020, there were 2,297,517 shares of our common stock issuable upon the exercise of Series 1 warrants outstanding, at an exercise price of $10.00 per share, and there were 2,297,522 shares of our common stock issuable upon the exercise of Series 2 warrants outstanding, at an exercise price of $13.00 per share. To the extent that these warrants have been or may be exercised, our stockholders may experience further dilution.

We may also seek additional funding through government or other third-party funding and other collaborations, strategic alliances and licensing arrangements. These financing activities may have an adverse impact on our stockholders’ rights as well as on our operations, and such additional funding may not be available on reasonable terms, if at all. Furthermore, these securities may have rights senior to those of our common stock and could contain covenants that would restrict our operations and potentially impair our competitiveness, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. For example, on February 7, 2020, we entered into the Credit Facility with Hercules, which provided for aggregate maximum borrowings of up to $30.0 million, consisting of (i) a term loan of up to $20.0 million, which was funded on February 7, 2020, and (ii) subject to

Hercules’ investment committee approval, an additional term loan of up to $10.0 million, available for borrowing from February 7, 2020 to December 15, 2020. Borrowings under the loan agreement are collateralized by substantially all of our and our subsidiaries personal property and other assets, other than our intellectual property. In addition, the loan agreement includes customary affirmative and restrictive covenants and representations and warranties, including a covenant against the occurrence of a “change in control,” financial reporting obligations, and certain limitations on indebtedness, liens (including a negative pledge on intellectual property and other assets), investments, distributions (including dividends), collateral, investments, distributions, transfers, mergers or acquisitions, taxes, corporate changes, and deposit accounts.

Additionally, if we seek funds through arrangements with collaborative partners, these arrangements may require us to relinquish rights to some of our technologies or product candidates or otherwise agree to terms unfavorable to us. Any of these events could significantly harm our business, financial condition and prospects.

If securities or industry analysts do not publish research or reports about our business, or if they issue an adverse or misleading opinion regarding our stock, our stock price and trading volume could decline.

The trading market for our common stock is influenced by the research and reports that industry or securities analysts publish about us or our business. If no or few securities or industry analysts continue coverage of us, the trading price for our stock could be negatively impacted. If any of the analysts who cover us issue an adverse or misleading opinion regarding us, our business model, our intellectual property or our stock performance, or if our trials or operating results fail to meet the expectations of analysts, our stock price could decline. If one or more of these analysts cease coverage of us or fail to publish reports on us regularly, we could lose visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.

Our principal stockholders and management own a significant percentage of our stock and will be able to exert significant control over matters subject to stockholder approval.

As of April 1, 2020, our executive officers, directors, holders of 5% or more of our capital stock and their respective affiliates beneficially own approximately 54.4% of our outstanding voting stock and options. These stockholders may be able to determine all matters requiring stockholder approval. For example, these stockholders may be able to control 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 feel are in your best interest as one of our stockholders. The interests of this group of stockholders may not always coincide with your interests or the interests of other stockholders and they may act in a manner that advances their best interests and not necessarily those of other stockholders, including seeking a premium value for their common stock, and might affect the prevailing market price for our common stock.

We are an “emerging growth company” as defined in the JOBS Act and a “smaller reporting company” and may avail ourselves of reduced disclosure requirements applicable to such companies, which could make our common stock less attractive to investors and adversely affect the market price of our common stock.

For so long as we remain an “emerging growth company” as defined in the JOBS Act, we may take advantage of certain exemptions from various requirements applicable to public companies that are not “emerging growth companies” including:

We may take advantage of these exemptions until we are no longer an “emerging growth company.” We would cease to be an “emerging growth company” upon the earliest of: (i) December 31, 2021; (ii) the first fiscal year after our annual gross revenues are $1.07 billion or more; (iii) the date on which we have, during the previous three-year period, issued more than $1.0 billion in non-

convertible debt securities; or (iv) as of the end of any fiscal year in which the market value of our common stock held by non-affiliates exceeded $700 million as of the end of the second quarter of that fiscal year.

We currently take advantage of some, but not all, of the reduced regulatory and reporting requirements that are available to us so long as we qualify as an “emerging growth company.” For example, we have irrevocably elected not to take advantage of the extension of time to comply with new or revised financial accounting standards available under Section 102(b) of the JOBS Act. Our independent registered public accounting firm is not be required to provide an attestation report on the effectiveness of our internal control over financial reporting so long as we qualify as an “emerging growth company,” which may increase the risk that material weaknesses or significant deficiencies in our internal control over financial reporting go undetected. Likewise, so long as we qualify as an “emerging growth company,” we may elect not to provide you with certain information, including certain financial information and certain information regarding compensation of our executive officers, that we would otherwise have been required to provide in filings we make with the Securities and Exchange Commission, or SEC, which may make it more difficult for investors and securities analysts to evaluate our company. We cannot predict if investors will find our common stock less attractive because we may rely on 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 and may decline.

We are also a smaller reporting company as defined in the Securities Exchange Act of 1934, as amended, or the Exchange Act. We may continue to be a smaller reporting company even after we are no longer an emerging growth company. We may take advantage of certain of the scaled disclosures available to smaller reporting companies and will be able to take advantage of these scaled disclosures for so long as (i) our voting and non-voting common stock held by nonaffiliates is less than $250.0 million measured on the last business day of our second fiscal quarter or (ii) our annual revenue is less than $100.0 million during the most recently completed fiscal year and our voting and non-voting common stock held by non-affiliates is less than $700.0 million measured on the last business day of our second fiscal quarter.

We will continue to incur significant costs as a result of operating as a public company, and our management will devote substantial time to compliance initiatives.

As a public company, we will incur significant legal, accounting and other expenses that we did not incur as a private company, and these expenses may increase even more after we are no longer an “emerging growth company.” We are subject to the reporting requirements of the Exchange Act, the Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Protection Act, as well as rules adopted, and to be adopted, by the SEC and the Nasdaq Global Select Market.

Sales of a substantial number of shares of our common stock in the public market could cause our stock price to fall.

Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. In August 2019, we entered into a sales agreement with Cowen and Company, LLC, or Cowen, under which we may issue and sell shares of our common stock having aggregate sales proceeds of up to $50.0 million from time to time through Cowen, acting as agent, in a series of one or more ATM equity offerings, or the 2019 ATM Program. Cowen is not required to sell any specific amount but acts as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. To date no shares of common stock were sold under the 2019 ATM program.

We may be subject to securities litigation, which is expensive and could divert management attention.

The market price of our common stock may be volatile, and in the past, companies that have experienced volatility in the market price of their stock have been subject to securities class action litigation. We may be the target of this type of litigation in the future. Securities litigation against us could result in substantial costs and divert our management’s attention from other business concerns, which could seriously harm our business.

If we fail to maintain an effective system of internal control over financial reporting in the future, we may not be able to accurately report our financial condition, results of operations or cash flows, which may adversely affect investor confidence in us and, as a result, the value of our common stock.

The Sarbanes-Oxley Act requires, among other things, that we maintain effective internal controls for financial reporting and disclosure controls and procedures. Commencing after the filing of our initial annual report on Form 10-K, we will be required, under Section 404 of the Sarbanes-Oxley Act, to furnish a report by management on, among other things, the effectiveness of our internal control over financial reporting. This assessment will need to include disclosure of any material weaknesses identified by our management in our internal control over financial reporting. A material weakness is a deficiency, or combination of deficiencies, in internal control over financial reporting that results in more than a reasonable possibility that a material misstatement of annual or

interim financial statements will not be prevented or detected on a timely basis. Section 404 of the Sarbanes-Oxley Act also generally requires an attestation from our independent registered public accounting firm on the effectiveness of our internal control over financial reporting. However, for as long as we remain an emerging growth company as defined in the JOBS Act, we intend to take advantage of the exemption permitting us not to comply with the independent registered public accounting firm attestation requirement. Our compliance with Section 404 will require that we incur substantial expense and expend significant management efforts. We currently do not have an internal audit group, and we will need to hire additional accounting and financial staff with appropriate public company experience and technical accounting knowledge, and compile the system and process documentation necessary to perform the evaluation needed to comply with Section 404. We may not be able to complete our evaluation, testing and any required remediation in a timely fashion. During the evaluation and testing process, if we identify one or more material weaknesses in our internal control over financial reporting, we will be unable to assert that our internal control over financial reporting is effective. We cannot assure you that there will not be material weaknesses or significant deficiencies in our internal control over financial reporting in the future. Any failure to maintain internal control over financial reporting could severely inhibit our ability to accurately report our financial condition, results of operations or cash flows. If we are unable to conclude that our internal control over financial reporting is effective, or if our independent registered public accounting firm determines we have a material weakness or significant deficiency in our internal control over financial reporting once that firm begin its Section 404 reviews, we could lose investor confidence in the accuracy and completeness of our financial reports, the market price of our common stock could decline, and we could be subject to sanctions or investigations by the Nasdaq Global Select Market, the SEC or other regulatory authorities. Failure to remedy any material weakness in our internal control over financial reporting, or to implement or maintain other effective control systems required of public companies, could also restrict our future access to the capital markets.

Some provisions of our charter documents and Delaware law may have anti-takeover effects that could discourage an acquisition of us by others, even if an acquisition would benefit our stockholders and may prevent attempts by our stockholders to replace or remove our current management.

Provisions in our amended and restated certificate of incorporation and amended and restated bylaws, 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. These provisions include a classified board of directors, a prohibition on actions by written consent of our stockholders and the ability of our board of directors to issue preferred stock without stockholder approval. These provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors, who are responsible for appointing the members of our management. Because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, or the DGCL, which may discourage, delay or prevent someone from acquiring us or merging with us whether or not it is desired by or beneficial to our stockholders. Under the DGCL, a corporation may not, in general, engage in a business combination with any holder of 15% or more of its capital stock unless the holder has held the stock for three years or, among other things, the board of directors has approved the transaction. Any provision of our amended and restated certificate of incorporation or amended and restated bylaws or Delaware law that has the effect of delaying or deterring a change of 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.

Pursuant to the requirements of Section 13 or 15(d) 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.



Delaware	32-0162505
(State or Other Jurisdiction of Incorporation or Organization)	(IRS Employer Identification No.)

35 Gatehouse Drive, Building D, Floor 3 Waltham, Massachusetts	02451
(Address of Principal Executive Offices)	(Zip Code)

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	SNDX	The Nasdaq Stock Market, LLC

		Page

PART I. FINANCIAL INFORMATION

Item 1.	Unaudited Financial Statements:

	Condensed Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019	1

	Condensed Consolidated Statements of Comprehensive Loss for the three months ended March 31, 2020 and 2019	2

	Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2020 and 2019	3

	Notes to Condensed Consolidated Financial Statements	4

Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	16

Item 3.	Quantitative and Qualitative Disclosures About Market Risk	25

Item 4.	Controls and Procedures	25

PART II. OTHER INFORMATION

Item 1.	Legal Proceedings	27

Item 1A.	Risk Factors	27

Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	57

Item 3.	Defaults upon Senior Securities	57

Item 6.	Exhibits	58

	March 31, 2020		December 31, 2019
	(In thousands)
Accrued professional fees	$	373	$	403
Accrued compensation and related costs		1,223		2,800
Accrued clinical costs		5,664		6,726
Other		535		266
Total accrued expenses and other current liabilities	$	7,795	$	10,195

	Amount
Remainder of 2020	$	—
2021		3,057
2022		9,809
2023		7,134
Total principal outstanding		20,000
Unamortized final fee		49
Unamortized debt issuance costs		(257	)
Total	$	19,792

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

	March 31,
	2020		2019
Options to purchase common stock		6,897,802		5,629,120
Warrants to purchase common stock		4,595,039		4,595,039
Employee Stock Purchase Plan		24,214		27,471
Non-vested restricted stock units (RSUs)		15,000		—

	March 31, 2020
Common stock issuable under pre-funded warrants		5,838,287
Series 1 and 2 warrants		4,595,039
Options to purchase common stock		765,348
Employee Stock Purchase Plan		1,115,797

Exhibit No.		Description

3.1		Amended and Restated Certificate of Incorporation of the Company (incorporated herein by reference to Exhibit 3.1 to the Company’s Current Report on Form 8-K (File No. 001-37708), as filed with the SEC on March 8, 2016).

3.2		Amended and Restated Bylaws of the Company (incorporated herein by reference to Exhibit 3.2 to the Company’s Current Report on Form 8-K (File No. 001-37708), as filed with the SEC on March 8, 2016).

4.1		Form of Pre-Funded Warrant issued pursuant to the securities purchase agreement between the Company and Certain Purchasers, dated January 30, 2020 (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K (File No. 001-37708), as filed with the SEC on February 4, 2020).

10.1		Securities Purchase Agreement between the Company and the Investors, dated January 30, 2020 (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K (File No. 001-37708), as filed with the SEC on February 4, 2020).

10.2		Loan and Security Agreement dated February 7, 2020 between Syndax Pharmaceuticals, Inc. and Hercules Capital, Inc.

10.3		Non-employee Director Compensation Policy, as amended, February 12, 2020.

10.4		Amended and Restated Executive Employment Agreement by and between the Company and Briggs W. Morrison, M.D., dated as of April 27, 2020.

10.5		Amended and Restated Executive Employment Agreement by and between the Company and Michael A. Metzger, dated as of April 27, 2020.

10.6		Amended and Restated Executive Employment Agreement by and between the Company and Michael L. Meyers, M.D., Ph.D., dated as of April 27, 2020.

10.7		Amended and Restated Executive Employment Agreement by and between the Company and Richard P. Shea, dated as of April 27, 2020.

31.1		Certification of Principal Executive Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended.

31.2		Certification of Principal Financial Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended.

32.1*		Certifications of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

101		Financial statements from the Quarterly Report on Form 10-Q of Syndax Pharmaceuticals, Inc. for the quarter ended March 31, 2019, formatted in XBRL (eXtensible Business Reporting Language): (i) the Condensed Consolidated Balance Sheets; (ii) the Condensed Consolidated Statements of Comprehensive Loss; (iii) the Condensed Consolidated Statements of Cash Flows; and (iv) Notes to Condensed Consolidated Financial Statements.

By:		/s/ Briggs W. Morrison, M.D.
		Briggs W. Morrison, M.D.
		Chief Executive Officer
		(Principal Executive Officer)

By:		/s/ Richard P. Shea
		Richard P. Shea
		Chief Financial Officer and Treasurer
		(Principal Executive Officer and Principal Accounting Officer)