Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Summary of Significant Accounting Policies [Abstract]

Use of Estimates

a) Use of Estimates

The preparation of 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 disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the consolidated financial statements include: normal recurring accruals, including the accrual of research and development expenses; accrued restructuring costs; fair value of investments; valuation of deferred tax assets; and stock-based compensation. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. The Company uses the best information available to update its critical accounting estimates.

Concentration of Credit Risk

b) Concentration of Credit Risk

Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash and cash equivalents and short-term and long-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has not experienced any losses on deposits since inception. The Company’s short-term and long-term investments are invested in high grade securities with limited concentration in any one issuer, and as a result, the Company believes represent minimal credit risk.

Fair Value of Financials Instruments

c) Fair Value of Financials Instruments

The accounting guidance defines fair value, establishes a consistent framework for measuring fair value, and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability.

The carrying amounts of cash, cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses are reasonable estimates of their fair value because of the short maturity of these items.

Cash and Cash Equivalents

d) Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents primarily represent funds invested in readily available money market accounts. As of December 31, 2023 and 2022, the Company had cash and cash equivalents balances deposited at major financial institutions.

Investments

e) Investments

All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Those investments with contractual maturities 12 months or greater at the balance sheet date are considered long-term investments. Dividend and interest income are recognized in the Company’s consolidated statements of operations and comprehensive loss when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. Unrealized gains and losses are reported as a component of accumulated other comprehensive loss. The cost of the Company’s available-for-sale debt securities is adjusted for amortization of premium and accretion of discounts to maturity. The Company reviews its portfolio of available-for-sale debt securities, using both quantitative and qualitative factors, to determine if declines in fair value below cost have resulted from a credit-related loss or other factors. If the decline in fair value is due to credit-related factors, a loss is recognized in statements of operations, whereas if the decline in fair value is not due to credit-related factors, the loss is recorded in other comprehensive loss.

Property and Equipment, Net

f) Property and Equipment, Net

 Property and equipment, net are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which ranges between three to five years. Leasehold improvements are stated at cost and depreciated over the shorter of the estimated useful life or the remaining lease term at the time the asset is placed into service.

Impairment of Property and Equipment

g) Impairment of Property and Equipment

The Company accounts for the impairment of long-lived assets by reviewing these assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted-cash-flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. The Company did not recognize impairment losses for the periods ended December 31, 2023 and 2022.

Leases

h) Leases

The Company determines if an arrangement is or contains a lease at inception. For leases with a term greater than one year, right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the net present value of lease payments, the Company uses its incremental borrowing rate which represents an estimated rate of interest that the Company would have to pay to borrow equivalent funds on a collateralized basis at the lease commencement date. Leases are classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the consolidated statement of operations and comprehensive loss. The Company’s leases often include options to extend or terminate the lease. These options are included in the lease term when it is reasonably certain that the Company will exercise that option. As of December 31, 2023, it is reasonably certain that these options will not be exercised, and they are not included within the lease term. As disclosed in Note 16 below, in January and February of 2024, the Company entered into agreements to assign its leases.

Research and Development

i) Research and Development

Research and development expenses are expensed in the periods in which they are incurred. External expenses consist primarily of payments to outside consultants and contract research organizations in connection with the Company’s clinical trials, discovery and preclinical activities, process development, manufacturing activities, regulatory and other services. External expenses are recognized based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers or the estimate of the level of service that has been performed at each reporting date.

The Company makes estimates of accrued expenses as of each balance sheet date based on facts and circumstances known at that time. The Company periodically confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. The significant estimates in its accrued research and development expenses include the costs incurred for services performed by vendors in connection with research and development activities for which the Company has not yet been invoiced. Research and development expenses amounted to $90.8 million and $88.2 million for the years ended December 31, 2023 and 2022, respectively.

Redeemable Convertible Noncontrolling Interests

j) Redeemable Convertible Noncontrolling Interests

Prior to the Kinnjiu Transaction, the shares third parties owned in Kinnjiu represented an interest in the equity the Company did not control. The redeemable convertible noncontrolling interests attributable to other owners was classified in temporary equity on the consolidated balance sheets as the preferred stock was redeemable by the noncontrolling interests.

Since the preferred stock held at Kinnjiu did not represent a residual equity interest, net losses of Kinnjiu were not allocated to the preferred shares. As a result, the balance of the preferred stock classified as a redeemable convertible noncontrolling interest equaled the carrying value. Additionally, net losses of Kinnjiu were not allocated to the noncontrolling interest related to ordinary shares held by a third party as the amounts to be allocated were immaterial.

Commitments and Contingencies

k) Commitments and Contingencies

The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. The Company has not recorded any such liabilities as of December 31, 2023 and 2022.

Income Taxes

l) Income Taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date.

The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

As of December 31, 2023 and 2022, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes would result in a change in the estimated annual effective tax rate.

Stock-Based Compensation

m) Stock-Based Compensation

Stock-based compensation expense represents the cost of the grant date fair value of employee, officer, director and non-employee stock option grants, estimated in accordance with the applicable accounting guidance, recognized on a straight-line basis over the vesting period. The vesting period generally approximates the expected service period of the awards. The Company recognizes forfeitures as they occur.

The fair value of restricted stock units is based on the Company’s closing stock price on the grant date. The fair value of stock options is estimated using a Black-Scholes valuation model on the date of grant. This method requires certain assumptions be used as inputs, such as the fair value of the underlying common stock, expected term of the option before exercise, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend. Options granted have a maximum contractual term of ten years. The Company has limited historical stock option activity and therefore estimates the expected term of stock options granted using the simplified method, which represents the arithmetic average of the original contractual term of the stock option and its weighted-average vesting term. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. The risk-free interest rates used are based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. treasury notes with maturities approximately equal to the expected term of the stock options. The Company has historically not declared or paid any dividends and does not currently expect to do so in the foreseeable future, and therefore has estimated the dividend yield to be zero.

Comprehensive Loss

n) Comprehensive Loss

Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on investments and foreign currency gains and losses. The unrealized losses on available-for-sale investments and foreign currency translation adjustments are included as a component of other comprehensive loss that is excluded from the reported net loss.

Net Loss Per Share

o) Net Loss Per Share

Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, the Company’s common stock options are considered to be potentially dilutive securities. As 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 sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts).

	Years Ended December 31,
	2023			2022
Numerator
Net loss	$	(112,649	)	$	(116,271	)
Denominator
Weighted-average shares outstanding used in computing net loss per share, basic and diluted		46,575,378			44,065,749
Net loss per share, basic and diluted	$	(2.42	)	$	(2.64	)

The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable for the periods presented because including them would have been anti-dilutive:

	Years Ended December 31,
	2023		2022
Options to purchase common stock		9,692,516		9,107,467
Non-vested restricted stock units		200,900		287,916
Total		9,893,416		9,395,383

Recently Issued and Adopted Accounting Standards

p) Recently Issued and Adopted Accounting Standards

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) (ASC 326): Measurement of Credit Losses on Financial Instruments, which introduced the expected credit losses methodology for the measurement of credit losses on financial assets measured at amortized cost basis, replacing the previous incurred loss methodology. The amendments in Update 2016-13 added Topic 326, Financial Instruments—Credit Losses, made several consequential amendments to the Codification. Update 2016-13 also modified the accounting for available-for-sale debt securities, which must be individually assessed for credit losses when fair value is less than the amortized cost basis, in accordance with Subtopic 326-30, Financial Instruments— Credit Losses—Available-for-Sale Debt Securities. The guidance is effective for public business entities for annual periods beginning after December 15, 2019, including interim periods within those years. For all other entities, the standard is effective for annual periods beginning after December 15, 2022 and interim periods, therein. Early adoption is permitted. Since the Company has elected to use the extended transition period under the JOBS Act available to emerging growth companies (EGCs), the ASU is effective for the Company for fiscal years beginning after December 15, 2022. The Company adopted this standard on the required effective date of January 1, 2023. The ASU did not have a material impact on its consolidated financial statements and related disclosures.

In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures. The amendments require disclosure of incremental segment information on an annual and interim basis. The amendments also require companies with a single reportable segment to provide all disclosures required by this amendment and all existing segment disclosures in Accounting Standards Codification 280, Segment Reporting. The amendments are effective for fiscal years beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The Company does not expect the adoption of the amendments to have a significant impact on its financial statements.