0000950170-24-032819 | 10-K | XBRL Viewer

Income Taxes

12 Months Ended

Dec. 31, 2023

11. Income Taxes

The Company did not have any income tax expense for the years ended December 31, 2023 and 2022. The reconciliation of the federal statutory income tax rate to the Company’s effective tax rate is as follows:


	December 31,
	2023				2022
Federal statutory income tax rate		21.0		%		21.0		%
State income tax, net of federal benefit		—				7.0
Nondeductible expenses		(5.3	)			(0.5	)
Tax credits		23.8				8.9
Stock-based compensation		(0.8	)			—
Change in valuation allowance		(35.0	)			(36.4	)
Change in state apportionment - deferred tax impact		(3.7	)			—
Effective tax rate		—		%		—		%

Deferred Tax Assets and Liabilities

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s net deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2023			2022
Deferred tax assets:
Net operating loss carryforwards	$	33,400		$	33,871
Capitalized research and experimental costs		11,744			5,559
Accruals		626			369
Intangible assets		77			116
Tax credits		20,292			8,878
Operating lease liability		267			392
Other		991			1,568
Total gross deferred tax assets		67,397			50,753
Valuation allowance		(67,148	)		(50,359	)
Total deferred tax assets		249			394
Deferred tax liabilities:
Operating lease right-of-use asset		(248	)		(392	)
Other		(1	)		(2	)
Total deferred tax liabilities		(249	)		(394	)
Total net deferred tax assets	$	—		$	—

Management regularly assesses the ability to realize deferred tax assets recorded based upon the weight of available evidence, including such factors as recent earnings history and expected future taxable income on a jurisdiction by jurisdiction basis. In the event that the Company changes its determination as to the amount of realizable deferred tax assets, the Company will adjust its valuation allowance with a corresponding impact to the provision for income taxes in the period in which such determination is made. The Company’s management believes that, based on a number of factors, it is more likely than not, that all or some portion of the deferred tax assets will not be realized; and accordingly, for the year ended December 31, 2023, the Company has provided a valuation allowance against the Company’s U.S. net deferred tax assets. The valuation allowance increased by $16.8 million during the year ended December 31, 2023, primarily due to an increase in the net operating loss (primarily from pre-tax book loss) and an increase in current year capitalization of Section 174 research and experimental costs. The valuation allowance increased by $17.0 million during the year ended December 31, 2022, primarily due to an increase in the net operating loss (primarily from pre-tax book loss) and the current year capitalization of Section 174 research and experimental costs.

As of December 31, 2023, the Company had net operating loss carryforwards for federal and state income tax purposes of approximately $118.2 million and $123.0 million, respectively, both of which will begin to expire in 2036 with the exception of $111.0 million of the Company's federal net operating losses that carry over indefinitely.

As of December 31, 2023, the Company had federal general business credit and state research and development credit carryforwards of approximately $22.2 million and $1.7 million, respectively. The federal general

business credit carryforwards will begin to expire in 2036 while the California research credit carryforwards have an indefinite life.

The Internal Revenue Code of 1986, as amended, imposes restrictions on the utilization of net operating losses in the event of an “ownership change” of a corporation. Accordingly, a company’s ability to use net operating losses may be limited as prescribed under Internal Revenue Code Section 382 (“IRC Section 382”). Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. Utilization of the federal and state net operating losses may be subject to substantial annual limitation due to the ownership change limitations provided by the IRC Section 382 and similar state provisions.

The Company files income tax returns in the U.S. federal jurisdiction and California state jurisdiction. The Company is not currently under audit by the Internal Revenue Service or any other similar state, local, or foreign authority. All tax years remain open to examination by major taxing jurisdictions to which the Company is subject.

Uncertain Income Tax Positions

The Company had approximately $3.2 million and $3.0 million of unrecognized tax benefits as of December 31, 2023 and 2022, respectively. No liability related to uncertain tax positions is recorded in the financial statements due to the fact the liabilities have been netted against deferred attribute carryovers. The unrecognized tax benefits would not impact the annual effective tax rate if recognized because the Company has recorded a valuation allowance on its deferred tax assets. The Company does not expect the amount of unrecognized tax benefits to materially change in the next 12 months. As of December 31, 2023 and 2022, the Company has not recognized any tax-related penalties or interest in its financial statements.

A reconciliation of the beginning and ending balance of the unrecognized tax benefits is as follows (in thousands):


	December 31,
	2023			2022
Balance at the beginning of the period	$	2,959		$	1,589
Increases based on tax positions related to current period		956			1,433
Increases based on tax positions related to prior period		1,520			—
Decreases based on tax positions related to prior period		(2,195	)		(63	)
Balance at the end of the period	$	3,240		$	2,959

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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+ Details

Organization and Principal Activities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Feb. 28, 2023	Oct. 31, 2020	Dec. 31, 2023	Dec. 31, 2022	Feb. 28, 2022
Organization And Principal Activities [Line Items]
Net loss			$ (47,919)	$ (46,180)
Cash in operations			33,300
Accumulated deficit			(197,232)	$ (149,313)
Cash, cash equivalents, and short-term investments			$ 96,300
Shelf Registration And Sales Agreement
Organization And Principal Activities [Line Items]
Maximum amount of sale covered in shelf registration statement					$ 200,000
Jefferies LLC \| Shelf Registration And Sales Agreement
Organization And Principal Activities [Line Items]
Maximum amount of offering issuance and sale covered in sales agreement					$ 21,000
Redeemable Convertible Preferred Stock
Organization And Principal Activities [Line Items]
Redeemable convertible preferred stock converted into common stock		15,492,019
Initial Public Offering
Organization And Principal Activities [Line Items]
Offering price		$ 15
Net proceeds of common stock		$ 93,400
Initial Public Offering \| Common Stock
Organization And Principal Activities [Line Items]
Initial public offering of common stock		6,900,000
Overallotment Option \| Common Stock
Organization And Principal Activities [Line Items]
Initial public offering of common stock		900,000
Private Placement
Organization And Principal Activities [Line Items]
Proceeds from issuance of private placement	$ 53,600
Private Placement \| Common Stock
Organization And Principal Activities [Line Items]
Initial public offering of common stock	16,116,000
Private Placement \| Pre-Funded Warrants
Organization And Principal Activities [Line Items]
Number of warrants issued	800,000
Private Placement \| Standard Warrants
Organization And Principal Activities [Line Items]
Number of warrants issued	12,687,000

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 96,339	$ 24,487
Short-term investments	0	54,590
Prepaid expenses	3,876	3,320
Other current assets	1,968	1,211
Total current assets	102,183	83,608
Right-of-use assets	1,181	1,400
Other assets	582	640
Total assets	103,946	85,648
Current liabilities:
Accounts payable	3,332	1,426
Accrued expenses and other current liabilities	14,600	9,399
Term loan, current portion	1,622	1,622
Deferred revenue	4,911	0
Total current liabilities	24,465	12,447
Lease liabilities, net of current portion	1,019	1,261
Term loan, net of current portion	1,717	3,293
Other liabilities	236	161
Total liabilities	27,437	17,162
Commitments and contingencies (Note 7)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding as of December 31, 2023 and 2022	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized as of December 31, 2023 and 2022; 41,029,832 and 23,601,004 shares issued and outstanding as of December 31, 2023 and 2022, respectively	4	3
Additional paid-in capital	273,737	218,354
Accumulated other comprehensive loss	0	(558)
Accumulated deficit	(197,232)	(149,313)
Total stockholders' equity	76,509	68,486
Total liabilities and stockholders' equity	$ 103,946	$ 85,648

STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Statement of Stockholders' Equity [Abstract]
Offering costs	$ 2,721

Stock-Based Compensation - Summary of Stock Option Activity - 2020 Equity Incentive Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested and expected to vest, Outstanding Stock Options	125,000
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning Balance, Outstanding Stock Options	4,166,194
Granted, Outstanding Stock Options	270,000
Exercised, Outstanding Stock Options	(54)
Forfeited, Outstanding Stock Options	(338,764)
Ending Balance, Outstanding Stock Options	4,097,376	4,166,194
Vested and expected to vest, Outstanding Stock Options	3,972,376
Vested and exercisable, Outstanding Stock Options	2,622,154
Beginning Balance, Weighted-Average Exercise Price	$ 3.38
Granted, Weighted-Average Exercise Price	2.26
Exercised, Weighted-Average Exercise Price	3.07
Forfeited, Weighted-Average Exercise Price	4.85
Ending Balance, Weighted-Average Exercise Price	3.19	$ 3.38
Vested and expected to vest, Weighted-Average Exercise Price	3.15
Vested and exercisable, Weighted-Average Exercise Price	$ 3.13
Weighted-Average Remaining Contractual Life (Years)	7 years 2 months 12 days	7 years 8 months 12 days
Vested and expected to vest, Weighted-Average Remaining Contractual Life (Years)	7 years 2 months 12 days
Vested and exercisable, Weighted-Average Remaining Contractual Life (Years)	6 years 6 months
Aggregate Intrinsic Value	$ 3,050	$ 52
Vested and expected to vest, Aggregate Intrinsic Value	3,050
Vested and exercisable, Aggregate Intrinsic Value	$ 2,249

401(k) Retirement Savings Plan

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

401(k) Retirement Savings Plan

12. 401(k) Retirement Savings Plan

In December 2017, the Company adopted a plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”) for all employees who have met certain eligibility requirements. Under the 401(k), employees may elect to contribute a portion of their eligible compensation, subject to certain limitations. During the years ended December 31, 2023 and 2022, the Company incurred expense of $0.1 million, respectively.

- Definition

The entire disclosure for retirement benefits.

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+ Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. Certain prior period amounts in the balance sheet and the statement of cash flows have been reclassified to conform to the current period presentation.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, revenue recognition, stock-based compensation, and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Risks and Uncertainties

Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration (“FDA”) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements.

The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical success of the Company’s product candidate, tildacerfont, ability to obtain regulatory approval of tildacerfont, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition, untested manufacturing capabilities, and dependence on key individuals and sole source suppliers.

Global economic and business activities continue to face widespread macroeconomic and geopolitical uncertainties, including recent and potential future disruptions in access to bank deposits or lending commitments due to bank failures, labor shortages, inflation and monetary supply shifts, recession risks and potential disruptions from the ongoing wars in Ukraine and Israel and related sanctions. The Company continues to actively monitor the impact of these macroeconomic and geopolitical factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.

Concentration of Credit Risk

Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial

institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheets.

Segment Reporting

The Company operates and manages its business as one operating segment, which is the business of developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in the United States of America.

Cash and Cash Equivalents

The Company considers all highly liquid investments with remaining maturities at the date of purchase of three months or less to be cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value.

Restricted Cash

The Company had $35 thousand and $0.2 million of restricted cash as of December 31, 2023 and 2022, respectively, which is related to collateralized cash in connection with letters of credit issued on behalf of the Company for the security deposits required under operating leases. Short-term restricted cash is included in other current assets on the balance sheets and long-term restricted cash is included in other assets on the balance sheets.

Fair Value of Financial Instruments

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value.

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

▪

Level 1—Quoted prices in active markets for identical assets and liabilities;

▪

Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and

▪

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company’s financial instruments primarily consist of cash and cash equivalents, prepaid expenses, accounts payable, term loan, and accrued expenses. The carrying value of cash and cash equivalents, prepaid expenses, accounts payable, and accrued expenses are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The estimated fair value of the term loan is based on market observable interest rates, which is considered a Level 2 fair value measurement.

Investments

The Company adopted Accounting Standards Update (“ASU”) 2016-13, Measurement of Credit Losses on Financial Instruments, on January 1, 2023. The Company’s investments are classified as available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term investments, or long-term investments. Management determines the appropriate classification of the investments at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months are considered long-term investments.

For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net.

Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement of operations and comprehensive loss.

For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the balance sheets.

Leases

The Company determines if an arrangement includes a lease at inception. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset includes any lease payments made on or before the lease commencement date, less lease incentives received. The incremental borrowing rate is used in determining the present value of future payments. The Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease. Lease expense for operating leases is recognized on a straight-line basis over the non-cancelable lease term. Variable lease expense relates primarily to office lease common area maintenance, insurance, and property taxes, is expensed as incurred, and is excluded from the calculation of the lease liability and right-of-use-asset. The Company does not have any finance leases.

The Company has elected not to recognize a right-of-use asset and lease liability for short-term leases. A short-term lease is a lease with an expected lease term of 12 months or less and which does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. Lease agreements that include lease and non-lease components are accounted for as a single lease component.

Property and Equipment, Net

Property and equipment are stated at cost less accumulated depreciation and are included in other assets on the balance sheets. Depreciation expense is calculated using the straight-line method over the estimated useful life of the respective asset and begins at the time the asset is placed into service. Maintenance and repairs are charged to expense as incurred, and improvements are capitalized.

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Furniture and fixtures	5 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years

Long-Lived Assets

Long-lived assets, such as property and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully 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. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary. There were no such impairment losses during the years ended December 31, 2023 and 2022.

Accrued Research and Development Expenses

Clinical trial costs are charged to research and development expense as incurred. The Company accrues for expenses resulting from contracts with clinical research organizations (“CROs”), consultants, and clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to us under such contracts. The Company’s policy is to reflect the appropriate expense in the financial statements by matching the appropriate expenses with the period in which services and efforts are expended.

The CRO contracts generally include pass-through fees including, but not limited to, regulatory expenses, investigator fees, laboratory fees and other miscellaneous costs. The Company determines accrual estimates through reports from and discussion with clinical personnel and outside service providers as to the progress or state of completion of trials, or the services completed. The Company estimates accrued expenses as of each balance sheet date based on the facts and circumstances known at that time. The clinical trial accrual is dependent, in part, upon the receipt of timely and accurate reporting from the CROs and other third-party vendors.

If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments associated with licensing agreements to acquire exclusive licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternate commercial use are expensed as incurred. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered.

Revenue Recognition

The Company recognizes revenues when, or as, the promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those services. To determine revenue recognition for arrangements, the Company performs the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligation(s) in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation(s) in the contract; and (5) recognize revenue when (or as) the performance obligation(s) are satisfied.

The Company has entered into a licensing and collaboration agreement that primarily includes the following: (i) upfront cash consideration; (ii) payments associated with achieving certain milestones; and (iii) royalties based on specified percentages of net product sales, if any. At the initiation of an agreement, the Company analyzes each unit of account within the contract to determine if the counterparty is a customer in the context of the unit of account.

At contract inception, the Company assesses the goods or services promised and enforceable in a contract with a customer and identifies those distinct goods and services that represent a performance obligation. If a promised good or service is not distinct, the Company combines that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. Promised goods and services that are not material in the context of the contract are not considered performance obligations. Additional goods or services that are exercisable at a customer’s discretion are assessed to determine if they provide a material right to the customer and if so, they are considered performance obligations.

The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The consideration promised in a contract with a customer

may include fixed amounts, variable amounts, or both. Non-refundable upfront payments are considered fixed consideration and included in the transaction price. At the inception of arrangements that include variable consideration, the Company uses judgment to estimate the amount of variable consideration to include in the transaction price using the most likely method. If it is probable that a significant revenue reversal will not occur, then the estimated amount is included in the transaction price. Milestone payments that are not within the Company’s or the licensee’s control, such as regulatory approvals, are not included in the transaction price until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and if the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied. At the end of each reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint and, as necessary, adjusts the estimate of the overall transaction price. Any adjustments will be recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment.

If it is determined that multiple performance obligations exist, the transaction price is allocated at the inception of the agreement to all identified performance obligations based on the relative standalone selling prices, unless the consideration is variable and meets the criteria to be allocated entirely to one or more, but not all, performance obligations in the contract. Other components of the transaction price are allocated based on the relative standalone selling price, over which the Company applies significant judgment. The Company develops assumptions that require judgment to determine the standalone selling price for license-related performance obligations under the adjusted market assessment approach, which may include forecasted revenues, development timelines, discount rates and probabilities of success.

Revenue is recognized when, or as, the Company satisfies a performance obligation. The Company recognizes revenue over time by measuring the progress toward complete satisfaction of the relevant performance obligation using an appropriate input method based on the nature of the good or service promised to the customer. The Company uses judgment to assess the nature of the performance obligation to determine whether the performance obligation is satisfied over time or at a point in time. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided.

If a customer pays consideration, or the Company has an unconditional right to the consideration, before the satisfaction of the revenue recognition criteria, the amounts are recorded as deferred revenue in the Company’s balance sheet. The current portion of deferred revenue represents the amount of the performance obligation that is expected to be satisfied within the next twelve months. Amounts recognized as revenue prior to receipt or before they are due are recorded as contract assets in the Company’s balance sheet, excluding any amounts presented as accounts receivable. If the Company has an unconditional right to receive consideration, the contract assets are accounted for as accounts receivable and presented separately from contract assets. A net contract asset or liability is presented for each contract with a customer.

Research and Development Expenses

Research and development costs are expensed as incurred. Research and development expenses include, but are not limited to, personnel costs, fees paid to external entities that conduct certain non-clinical and clinical development activities on our behalf, manufacturing costs, outside service and consulting costs, and allocated overhead, including rent. Assets acquired that are utilized in research and development that have no alternative future use are also expensed as incurred.

Stock-Based Compensation

The Company accounts for stock-based compensation using a fair value-based method, which requires the recognition of compensation expense for costs related to all stock-based payments including stock options, restricted stock units (“RSUs”) and purchase rights under the Employee Stock Purchase Plan (“ESPP”). The Company estimates the fair value of stock options and purchase rights granted under the ESPP on the date of grant using the Black-Scholes option pricing model, which is impacted by the fair value of the Company’s common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. The model requires management to make a number of assumptions which include the following:

▪

Expected Term. The expected term is based on the simplified method, as the Company’s stock options have the following characteristics: (i) granted at-the-money; (ii) exercisability is conditioned upon service through the vesting date; (iii) termination of service prior to vesting results in forfeiture; (iv) limited exercise period following termination of service; and (v) options are non-transferable and non-hedgeable, or “plain vanilla” options, and the Company has limited history of exercise data. For the ESPP, the expected term is based on the term of the purchase period.

▪

Expected Volatility. The expected volatility is estimated using a combination of historical volatilities of the Company's stock and that of comparable publicly traded biopharmaceutical companies. In evaluating similarity, the Company considered factors such as market capitalization, stage of development, area of specialty, and stock-specific attributes. The Company will continue to apply this process and analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available.

▪

Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury constant maturity rates with remaining terms similar to the expected term of the options.

▪

Expected Dividend Rate. The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.

▪

Forfeitures. The Company accounts for forfeitures as they occur.

The fair value of RSUs, including RSUs subject to performance-based vesting conditions, is based on the grant-date fair value of the Company's stock price.

The Company recognizes compensation expense on a straight-line basis over the requisite service period of the award, which is generally the vesting period. The Company accounts for forfeitures as they occur.

For options and RSUs that vest upon the satisfaction of certain performance conditions, the Company recognizes compensation expense when it becomes probable that the performance conditions will be met. When the criteria are deemed probable of being met, the Company records cumulative compensation expense in the period the performance criteria are deemed probable of being met and recognizes the remaining compensation expense on a straight-line basis over the remaining period for which the performance criteria are expected to be completed.

Income Taxes

The Company accounts for income taxes under the asset and liability method. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differences in accounting for reporting purposes and tax purposes for certain items, such as accruals and allowances not currently deductible for tax purposes. These temporary differences result in deferred tax assets and liabilities. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the Company’s statements of operations and comprehensive loss become deductible expenses under applicable income tax laws or when net operating loss or credit carryforwards are utilized. Accordingly, realization of the Company’s deferred tax assets is dependent on future taxable income against which these deductions, losses and credits can be utilized.

The Company assesses the likelihood that the Company’s deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. The assessment of whether or not a valuation allowance is required often requires significant judgment, including the forecast of future taxable income and on-going prudent and feasible tax planning initiatives. Based upon the weight of available evidence, the Company has determined that net deferred tax assets should be fully offset by a valuation allowance. When the Company establishes or reduces the valuation allowance against its net deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made.

The Company accounts for uncertainty in income taxes in accordance with Accounting Standards Codification 740. Tax positions are evaluated in a two-step process, whereby the Company first determines whether it is more likely than not that a tax position will be sustained upon examination by tax authorities, including resolutions of any related appeals or litigation processes, based on technical merit. If a tax position meets the more-likely-than-not recognition threshold, it is then measured to determine the amount of benefit to be recognized in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to the

underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits.

Comprehensive loss

Comprehensive loss represents the net loss for the period and other comprehensive income. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ equity and are not reflected in the statements of operations. The Company’s other comprehensive loss consists of changes in unrealized gains and losses on available-for-sale investments, net of tax. There was no income tax effect related to unrealized gains and losses during the years ended December 31, 2023 and 2022.

Net Loss per Share

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted 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 stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, outstanding stock options, RSUs, and shares expected to be issued pursuant to the ESPP are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods.

Emerging Growth Company Status

The Company is an emerging growth company (“EGC”) as defined in the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.

Recent Accounting Pronouncements Adopted

In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. ASU 2016-13 also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. The Company adopted ASU 2016-13 on January 1, 2023 and the adoption did not have any impact on the Company’s financial statements.

Recent Accounting Pronouncements - Not Yet Adopted

In December 2023, the FASB issued Accounting Standards Update 2023-09, Income Taxes - Improvements to Income Tax Disclosures (“ASU 2023-09”) requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s financial statements and related disclosures.

In November 2023, the FASB issued ASU 2023-07, Improvements to Reportable Segment Disclosures (“ASU 2023-07”) which is intended to improve reportable segment disclosure requirements, primarily through additional disclosures about significant segment expenses, including for single reportable segment entities. The standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years

beginning after December 15, 2024, with early adoption permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. We are evaluating the disclosure requirements related to the new standard.

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Related to Stock Options, RSUs and ESPP (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,622	$ 3,631
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,547	929
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,075	$ 2,702

Income Taxes - Schedule of Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Balance at the beginning of the year	$ 2,959	$ 1,589
Increases based on tax positions related to current period	956	1,433
Increases based on tax positions related to prior period	1,520	0
Decreases based on tax positions related to prior period	(2,195)	(63)
Balance at the end of the year	$ 3,240	$ 2,959

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of term loan	$ 3,600,000	$ 4,900,000
Allowance for credit losses	0
Debt securities, available-for-sale, realized gain (loss)	0
Debt securities, available-for-sale, realized gain (loss), excluding other-than-temporary impairment	0	0
Investments	0
Fair Value Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities fair value	0	0
Fair Value Non-recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities fair value	$ 0	$ 0

Term Loan (Tables)

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Schedule of Future Principal Payments

As of December 31, 2023, future payments of principal and interest are as follows (in thousands):


Year ending December 31,
2024	$	1,863
2025		1,714
2026		136
Total	$	3,713
Less: interest		(335	)
Term loan, gross	$	3,378
Less: unamortized debt issuance costs		(39	)
Less: term loan, current portion		(1,622	)
Term loan, net of current portion	$	1,717

Term Loan - Schedule of Future Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
2024	$ 1,863
2025	1,714
2026	136
Total	3,713
Less: interest	(335)
Term loan, gross	3,378
Less: unamortized debt issuance costs	(39)
Less: term loan, current portion	(1,622)	$ (1,622)
Term loan, net of current portion	$ 1,717	$ 3,293

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		December 31, 2023
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market funds	Level 1	$	95,875	$	—	$	—	$	95,875
Total cash equivalents		$	95,875	$	—	$	—	$	95,875


		December 31, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	22,496	$	—	$	—		$	22,496
Total cash equivalents			22,496		—		—			22,496
U.S. government treasury securities	Level 1		43,779		1		(516	)		43,264
Corporate bonds	Level 2		11,369		—		(43	)		11,326
Total short-term investments			55,148		1		(559	)		54,590
Total cash equivalents and investments		$	77,644	$	1	$	(559	)	$	77,086

Summary of investments in an unrealized loss position

Investments that were in an unrealized loss position as of December 31, 2022 consisted of (in thousands):


	December 31, 2022
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. government treasury securities	$	16,743	$	(77	)	$	23,585	$	(439	)	$	40,328	$	(516	)
Corporate bonds		—		—			11,326		(43	)		11,326		(43	)
Total short-term investments	$	16,743	$	(77	)	$	34,911	$	(482	)	$	51,654	$	(559	)

Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company classifies money market funds and U.S. treasury securities as Level 1 investments as the Company uses quoted prices in active markets for identical assets to determine the fair value. The Company classifies corporate bonds and commercial paper as Level 2 investments as the Company uses quoted prices for similar assets sourced from certain third-party pricing services. The third-party pricing services generally utilize industry standard valuation models for which all significant inputs are observable, either directly or indirectly, to estimate the price or fair value of the securities. The primary input generally includes reported trades of or quotes on the same or similar securities. The Company does not make additional judgments or assumptions made to the pricing data sourced from the third-party pricing services.

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		December 31, 2023
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market funds	Level 1	$	95,875	$	—	$	—	$	95,875
Total cash equivalents		$	95,875	$	—	$	—	$	95,875


		December 31, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	Level 1	$	22,496	$	—	$	—		$	22,496
Total cash equivalents			22,496		—		—			22,496
U.S. government treasury securities	Level 1		43,779		1		(516	)		43,264
Corporate bonds	Level 2		11,369		—		(43	)		11,326
Total short-term investments			55,148		1		(559	)		54,590
Total cash equivalents and investments		$	77,644	$	1	$	(559	)	$	77,086

There have been no realized gains or losses on available for sale securities for the periods presented. Unrealized gains and losses are included in “accumulated other comprehensive loss” within stockholders' equity on the balance sheets.

There were no investments as of December 31, 2023. Investments that were in an unrealized loss position as of December 31, 2022 consisted of (in thousands):


	December 31, 2022
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. government treasury securities	$	16,743	$	(77	)	$	23,585	$	(439	)	$	40,328	$	(516	)
Corporate bonds		—		—			11,326		(43	)		11,326		(43	)
Total short-term investments	$	16,743	$	(77	)	$	34,911	$	(482	)	$	51,654	$	(559	)

No allowance for credit losses has been recognized as of December 31, 2023. During the years ended December 31, 2023 and 2022, the Company did not recognize any impairment losses related to investments.

The estimated fair value of the term loan was $3.6 million and $4.9 million as of December 31, 2023 and 2022, respectively, and was based on market observable interest rates, a Level 2 input.

The Company did not have any financial liabilities recorded at fair value on a recurring or non-recurring basis as of December 31, 2023 and 2022.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Leases - Other information related to operating leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease costs	$ 337	$ 465
Cash paid for operating lease liabilities	$ 251	$ 492
Weighted average remaining lease term (years)	4 years 2 months 12 days	5 years 2 months 12 days
Weighted average discount rate	8.00%	8.00%

Income Taxes - Schedule of Significant Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carryforwards	$ 33,400	$ 33,871
Capitalized research and experimental costs	11,744	5,559
Accruals	626	369
Intangible assets	77	116
Tax credits	20,292	8,878
Operating lease liability	267	392
Other	991	1,568
Total gross deferred tax assets	67,397	50,753
Valuation allowance	(67,148)	(50,359)
Total deferred tax assets	249	394
Deferred tax liabilities:
Operating lease right-of-use asset	(248)	(392)
Other	(1)	(2)
Total deferred tax liabilities	$ (249)	$ (394)

Capital Structure - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Shares reserved for future issuance	21,019,708	7,704,202
Shares available for future issuance under 2020 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	675,038	601,819
Common Stock warrants, issued and outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	12,687,000	0
Stock Options, Issued and Outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	4,097,376	4,166,194
Restricted and performance stock units, issued and outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	3,482,663	1,996,128
Shares available for future issuance under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	77,631	940,061

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483014/272-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 272
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
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-Section 50
-Paragraph 13
-Subparagraph (a)
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Paragraph 18
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

+ Details

Income Taxes - Schedule of Reconciliation of the Federal Statutory Income Tax Rate to Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%
State income tax, net of federal benefit	0.00%	7.00%
Nondeductible expenses	(5.30%)	(0.50%)
Tax credits	23.80%	8.90%
Stock-based compensation	(0.80%)	0.00%
Change in valuation allowance	(35.00%)	(36.40%)
Change in state apportionment - deferred tax impact	(3.70%)	0.00%
Effective tax rate	0.00%	0.00%

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of Useful Lives of Property and Equipment

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Furniture and fixtures	5 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (47,919)	$ (46,180)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	4,622	3,631
Depreciation and amortization	70	74
Net amortization (accretion) of premium/discount on available-for-sale securities	(636)	16
Non-cash lease expense	230	355
Gain on lease termination	0	(750)
Loss on disposal of property and equipment	2	39
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,636)	(817)
Other assets	96	90
Accounts payable	1,906	(1,397)
Accrued expenses and other current liabilities	6,255	3,587
Deferred Revenue	4,911	0
Other liabilities	(176)	(331)
Net cash used in operating activities	(33,275)	(41,683)
Cash flows from investing activities
Proceeds from maturities of investments	67,665	60,500
Purchases of investments	(11,881)	(36,800)
Purchases of property and equipment	(7)	(8)
Net cash provided by investing activities	55,777	23,692
Cash flows from financing activities
Proceeds from Issuance of Common Stock and Warrants	53,616	0
Proceeds from issuance of common stock related to employee stock purchase plan	169	76
Proceeds from exercise of pre-funded warrants	8	0
Proceeds from exercise of common stock options	1	2
Payment of offering costs	(2,721)	(279)
Repayment of term loan	(1,622)	0
Tax withholding payments on restricted stock units	(311)	(40)
Net cash provided by (used in) financing activities	49,140	(241)
Net increase (decrease) in cash, cash equivalents, and restricted cash	71,642	(18,232)
Cash, cash equivalents, and restricted cash at beginning of period	24,732	42,964
Cash, cash equivalents, and restricted cash at end of period	96,374	24,732
Reconciliation of cash, cash equivalents, and restricted cash
Cash and cash equivalents	96,339	24,487
Restricted cash, short-term (included in other current assets)	0	216
Restricted cash, long-term (included in other assets)	35	29
Total cash, cash equivalents and restricted cash	96,374	24,732
Supplemental cash flow data:
Cash paid for interest on term loan	369	266
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs included in accrued expenses	51	53
Right-of-use assets recognized in exchange for lease liabilities	$ 11	$ 1,418

Capital Structure - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Equity [Abstract]
Common stock shares authorized	200,000,000	200,000,000
Common stock par value	$ 0.0001	$ 0.0001
Common stockholders voting rights	one vote
Common stock dividends declared	$ 0

Net Loss Per Share - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	20,393,190	6,465,558
Shares Subject to Outstanding Standard Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	12,687,000	0
Shares Subject To Outstanding Common Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	4,097,376	4,166,194
Shares subject to outstanding RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	3,482,663	1,996,128
Estimated shares issuable under the ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	126,151	303,236

401(k) Retirement Savings Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
401(K) Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contribution plan expense incurred	$ 0.1	$ 0.1

Balance Sheet Components

12 Months Ended

Dec. 31, 2023

Balance Sheet Components Disclosure [Abstract]

Balance Sheet Components

4. Balance Sheet Components

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2023		2022
Accrued research and development expenses	$	10,832	$	7,449
Accrued compensation and benefits		3,101		1,286
Accrued general and administrative expenses		416		525
Lease liabilities, current portion		251		139
Total accrued expenses and other current liabilities	$	14,600	$	9,399

Accrued research and development expenses were primarily related to clinical trials and manufacturing of clinical drug supply.

Summary of Significant Accounting Policies - Schedule of Useful Lives of Property and Equipment (Details)	Dec. 31, 2023
Computer and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	3 years
Computer Software
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	3 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	5 years
Manufacturing Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	7 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	15 years
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	us-gaap:UsefulLifeTermOfLeaseMember

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Year Ended December 31,
	2023			2022
Numerator:
Net loss	$	(47,919	)	$	(46,180	)
Denominator:
Weighted-average shares of common stock outstanding		38,510,220			23,527,116
Net loss per share, basic and diluted	$	(1.24	)	$	(1.96	)

Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share

Basic net loss per share was the same as diluted net loss per share for all periods as the inclusion of potentially dilutive securities would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations were as follows:


	December 31,
	2023		2022
Shares subject to outstanding Standard Warrants		12,687,000		—
Shares subject to outstanding common stock options		4,097,376		4,166,194
Shares subject to outstanding RSUs		3,482,663		1,996,128
Estimated shares issuable under the ESPP		126,151		303,236
Total		20,393,190		6,465,558

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2020	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance		21,019,708	7,704,202
Equity incentive plans terms		Following the effectiveness of the 2020 Plan, no further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.
Number of shares early exercised under any plan		0
Total stock options outstanding		125,000
Options vested in period, fair value		$ 4.0	$ 1.9
Weighted-average fair value of options granted		$ 1.65	$ 2.34
Unrecognized stock-based compensation expense		$ 6.8
RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average fair value of RSUs granted		$ 2	$ 1.24
RSUs granted		2,375,250
Fair value of RSUs vested in period		$ 0.9	$ 0.3
Intrinsic value of RSUs outstanding		$ 10.2	$ 2.2
Unrecognized stock-based compensation expense expected to be recognized over weighted-average vesting term		1 year 6 months
Time Based Vesting Installments Through June 30, 2023 \| RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted		1,449,300
Performance Based Vesting \| RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted		2,018,375
Performance Based Vesting \| RSU \| Clinical Development Milestones
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted		925,950
Probable of Achievement \| RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted		864,263
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance	2,647,684
Term of automatically increase in common stock available for issuance	10 years
Percentage of outstanding shares subject to automatic increase in common stock	5.00%
Equity incentive plans terms	In addition, the number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors.
Incentive stock options granted description		Board of Directors determines the per share exercise price of each stock option, which for ISOs shall not be less than 100% of the fair market value of a share on the date of grant; provided that the exercise price of an ISO granted to a stockholder who at the time of grant owns stock representing more than 10% of the voting power of all classes of stock (a 10% stockholder) shall not be less than 110% of the fair market value of a share on the date of grant.
Vesting period		4 years
Equity incentive plan, maximum term		5 years
Options termination term, if option holders service terminate		3 months
Total stock options outstanding		3,972,376
Shares remained available for issuance		77,631
2020 Equity Incentive Plan \| All Other Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity incentive plan, maximum term		10 years
2020 Equity Incentive Plan \| First Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage		25.00%
2020 Equity Incentive Plan \| Monthly Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage		2.083%
2020 Equity Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of incentive stock options granted		100.00%
Percentage of Exercise price of incentive stock options granted owns stock		10.00%
Fair market value exercise price percentage		110.00%
2016 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares remained available for issuance		0
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance	220,640
Term of automatically increase in common stock available for issuance	10 years
Percentage of outstanding shares subject to automatic increase in common stock	1.00%
Equity incentive plans terms		In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lessor of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.
Shares remained available for issuance	441,280	675,038
Maximum percentage of compensation that an employee is allowed to purchase shares	15.00%
Purchase price of common stock expressed as a percentage of fair market value	85.00%
Employee stock purchase plan offering period		provides for 24-month offering periods starting every January 1st and July 1st, each consisting of four six-month purchase periods

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment \| Segment	1
Restricted cash	$ 35,000	$ 200,000
Expected lease term	12 months
Impairment losses	$ 0	$ 0
Maximum
Summary Of Significant Accounting Policies [Line Items]
Percentage of tax positions likely of being realized upon ultimate settlement	50.00%

Stock-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

. Stock-Based Compensation

Equity Incentive Plans

The Company adopted the 2020 Equity Incentive Plan (the “2020 Plan”) in October 2020. The 2020 Plan is a successor to and continuation of the Amended and Restated 2016 Equity Incentive Plan (the “2016 Plan”) and provides for the granting of stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock or cash-based awards to individuals who are then employees, officers, directors or consultants. A total of 2,647,684 shares of common stock were approved to be initially reserved for issuance under the 2020 Plan. In addition, the number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors. Following the effectiveness of the 2020 Plan, no further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.

The Board of Directors determines the per share exercise price of each stock option, which for ISOs shall not be less than 100% of the fair market value of a share on the date of grant; provided that the exercise price of an ISO granted to a stockholder who at the time of grant owns stock representing more than 10% of the voting power of all classes of stock (a 10% stockholder) shall not be less than 110% of the fair market value of a share on the date of grant.

The Board of Directors determines the period over which options vest and become exercisable. Options granted to new employees generally vest over a four-year period: 25% of the shares vest on the first anniversary from the vesting commencement date of the option and an additional 1/48th of the shares vest on each monthly anniversary thereafter, subject to the employee’s continuous service through each vesting date.

The Board of Directors also determines the term of options, provided the maximum term for ISOs granted to a 10% stockholder must be no longer than five years from date of grant and the maximum term for all other options

must be no longer than ten years from date of grant. If an option holder’s service terminates, options generally terminate three months from the date of termination except under certain circumstances, such as death or disability.

Under the 2020 Plan and the 2016 Plan, individuals can be granted the ability to early exercise their options. There were no shares, related to the early exercise of options, subject to repurchase by the Company as of December 31, 2023. As of December 31, 2023, 77,631 shares remained available for issuance under the 2020 Plan and no shares remained available for issuance under the 2016 Plan.

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Balance as of December 31, 2022		4,166,194		$	3.38		7.7	$	52
Granted		270,000		$	2.26
Exercised		(54	)	$	3.07
Forfeited		(338,764	)	$	4.85
Balance as of December 31, 2023		4,097,376		$	3.19		7.2	$	3,050
Vested and expected to vest as of December 31, 2023		3,972,376		$	3.15		7.2	$	3,050
Vested and exercisable as of December 31, 2023		2,622,154		$	3.13		6.5	$	2,249

Stock options vested and expected to vest differs from total stock options outstanding as it excludes 125,000 performance-based stock options for which the performance criteria is not considered probable of achievement as of December 31, 2023.

The aggregate intrinsic values of options outstanding and exercisable were calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock as of the respective balance sheet date. The total intrinsic value of options exercised was immaterial for the years ended December 31, 2023 and 2022, respectively. The total fair value of options vested was $4.0 million and $1.9 million for the years ended December 31, 2023 and 2022, respectively.

Restricted Stock Units (“RSUs”)

A summary of the Company’s RSU activity and related information is as follows (in thousands, except share and per share amounts):


	Number of RSUs			Weight-Average Grant Date Fair Value
Balance as of December 31, 2022		1,996,128		$	1.35
Granted		2,375,250		$	2.00
Vested		(484,152	)	$	1.91
Forfeited		(404,563	)	$	2.40
Balance as of December 31, 2023		3,482,663		$	1.59

For the year ended December 31, 2022, the weighted average fair value of RSUs granted was $1.24 per share. The total fair value of RSUs vested was $0.9 million and $0.3 million for the years ended December 31, 2023 and 2022, respectively. The aggregate intrinsic value of RSUs outstanding as of December 31, 2023 and 2022 was $10.2 million and $2.2 million, respectively.

During the year ended December 31, 2023, the Company granted 2,375,250 RSUs, including 1,449,300 RSUs subject to time-based vesting in installments through December 2027 and 925,950 RSUs subject to performance-based vesting conditions related to the satisfaction of certain clinical development milestones.

As of December 31, 2023, the Company has granted 2,018,375 RSUs subject to performance-based vesting conditions, of which 864,263 RSUs are considered probable of achievement.

Employee Stock Purchase Plan

The Company’s Board of Directors adopted and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “ESPP”) in October 2020. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation. At the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock as of the offering date or the applicable purchase date. A total of 220,640 shares of common stock were approved to be initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lessor of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.

Except for the initial offering period, the ESPP provides for 24-month offering periods starting every January 1st and July 1st, each consisting of four six-month purchase periods. As of December 31, 2023, 675,038 shares of common stock remained available for issuance under the ESPP.

Stock-Based Compensation Expense

For the years ended December 31, 2023 and 2022, the weighted-average fair value of options granted was $1.65 and $2.34 per share, respectively.

The Company estimated the fair value of stock options and purchase rights under ESPP using the Black-Scholes option-pricing model, with the following weighted-average assumptions:


	2023						2022
	Options			ESPP			Options			ESPP
Expected term (in years)		5.6			1.4			6.0			1.4
Expected volatility		87.8	%		104.6	%		105.4	%		77.2	%
Risk-free interest rate		3.7	%		5.4	%		2.4	%		2.2	%
Expected dividend rate		0.0	%		0.0	%		0.0	%		0.0	%

The following table summarizes stock-based compensation expense related to stock options, RSUs and ESPP that is included in the Company’s statements of operations and comprehensive loss (in thousands):


	Year Ended December 31,
	2023		2022
Research and development	$	1,547	$	929
General and administrative		3,075		2,702
Total stock-based compensation expense	$	4,622	$	3,631

As of December 31, 2023, there was approximately $6.8 million of total unrecognized stock-based compensation expense related to awards that are expected to vest, which is expected to be recognized over an estimated weighted-average vesting term of 1.5 years.

STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2021	$ 111,371	$ 3	$ 214,685	$ (184)	$ (103,133)
Balance, Shares at Dec. 31, 2021		23,491,881
Exercise of common stock options	2		2
Exercise of common stock options, Shares		992
Issuance of common stock related to employee stock purchase plan	76		76
Issuance of common stock related to employee stock purchase plan,shares		66,299
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings	(40)		(40)
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings,shares		41,832
Stock-based compensation	3,631		3,631
Unrealized gain (loss) on available for sale securities	(374)			(374)
Net loss	(46,180)				(46,180)
Balance at Dec. 31, 2022	$ 68,486	$ 3	218,354	(558)	(149,313)
Balance, Shares at Dec. 31, 2022	23,601,004	23,601,004
Exercise of common stock options	$ 1		1
Exercise of common stock options, Shares		54
Exercise of pre-funded warrants	8		8
Exercise of pre-funded warrants, Shares		800,000
Issuance of common stock related to employee stock purchase plan	169		169
Issuance of common stock related to employee stock purchase plan,shares		162,791
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings	(311)		(311)
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings,shares		349,983
Issuance of common stock and warrants, net of offering costs, shares		16,116,000
Issuance of common stock and warrants, net of offering costs	50,895	$ 1	50,894
Stock-based compensation	4,622		4,622
Unrealized gain (loss) on available for sale securities	558			558
Net loss	(47,919)				(47,919)
Balance at Dec. 31, 2023	$ 76,509	$ 4	$ 273,737	$ 0	$ (197,232)
Balance, Shares at Dec. 31, 2023	41,029,832	41,029,832

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Mar. 10, 2024	Mar. 31, 2024	Dec. 31, 2023
RSU
Subsequent Event [Line Items]
Shares, Granted			2,375,250
Subsequent Event \| RSU \| Executive Officers
Subsequent Event [Line Items]
Shares, Granted		1,200,000
Subsequent Event \| Realignment Plan
Subsequent Event [Line Items]
Number of termination of study and reduction of workforce in percentage	21.00%
Cash charges	$ 0.4

Term Loan - Additional Information (Details) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2020 shares	Sep. 30, 2019 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) Installment	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Aggregate principal amount			$ 3,713
Term loan, gross			3,378
Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Aggregate principal amount		$ 4,500
Amount of total debt available			$ 30,000
Debt instrument, maturity date			Jan. 01, 2026
Interest rate of term loan			9.00%	8.00%
Number of monthly installments \| Installment			37
Unamortized debt discount and issuance costs			$ 39
Term loan, gross			$ 3,300
Term Loan \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Number of shares issuable upon the exercise of warrant \| shares		49,609
Warrants exercise price \| $ / shares		$ 1.44
Estimated fair value of the warrant		$ 100
Term Loan \| Silicon Valley Bank \| Maximum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage			2.00%
Term Loan \| Silicon Valley Bank \| Minimum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage			1.00%
Term Loan \| Common Stock \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Net exercised of common stock \| shares	46,358
First Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the first tranche			$ 20,000
End of term payment, amount			$ 300
End of term payment, percentage			6.00%
Debt issuance costs			$ 3,400
Second Tranche Term Loan
Debt Instrument [Line Items]
Commitments				$ 10,000
Second Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the second tranche			$ 10,000
Debt instrument, maturity date			Dec. 31, 2022
Second Tranche Term Loan \| Silicon Valley Bank \| Prime Rate
Debt Instrument [Line Items]
Floating interest scenario two			3.75%
Second Tranche Term Loan \| Silicon Valley Bank \| Prime Rate \| Maximum
Debt Instrument [Line Items]
Floating interest scenario one			0.50%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Reconciliation of the Federal Statutory Income Tax Rate to Effective Tax Rate

The reconciliation of the federal statutory income tax rate to the Company’s effective tax rate is as follows:


	December 31,
	2023				2022
Federal statutory income tax rate		21.0		%		21.0		%
State income tax, net of federal benefit		—				7.0
Nondeductible expenses		(5.3	)			(0.5	)
Tax credits		23.8				8.9
Stock-based compensation		(0.8	)			—
Change in valuation allowance		(35.0	)			(36.4	)
Change in state apportionment - deferred tax impact		(3.7	)			—
Effective tax rate		—		%		—		%

Schedule of Significant Components of Net Deferred Tax Assets and Liabilities

Significant components of the Company’s net deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2023			2022
Deferred tax assets:
Net operating loss carryforwards	$	33,400		$	33,871
Capitalized research and experimental costs		11,744			5,559
Accruals		626			369
Intangible assets		77			116
Tax credits		20,292			8,878
Operating lease liability		267			392
Other		991			1,568
Total gross deferred tax assets		67,397			50,753
Valuation allowance		(67,148	)		(50,359	)
Total deferred tax assets		249			394
Deferred tax liabilities:
Operating lease right-of-use asset		(248	)		(392	)
Other		(1	)		(2	)
Total deferred tax liabilities		(249	)		(394	)
Total net deferred tax assets	$	—		$	—

Schedule of Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits

A reconciliation of the beginning and ending balance of the unrecognized tax benefits is as follows (in thousands):


	December 31,
	2023			2022
Balance at the beginning of the period	$	2,959		$	1,589
Increases based on tax positions related to current period		956			1,433
Increases based on tax positions related to prior period		1,520			—
Decreases based on tax positions related to prior period		(2,195	)		(63	)
Balance at the end of the period	$	3,240		$	2,959

Capital Structure (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	December 31,
	2023		2022
Common Stock warrants, issued and outstanding		12,687,000		—
Stock options, issued and outstanding		4,097,376		4,166,194
Restricted and performance stock units, issued and outstanding		3,482,663		1,996,128
Shares available for future issuance under 2020 Equity Incentive Plan		77,631		940,061
Shares available for future issuance under 2020 Employee Stock Purchase Plan		675,038		601,819
Total shares reserved		21,019,708		7,704,202

Organization and Principal Activities

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Principal Activities

1. Organization and Principal Activities

Description of Business

Spruce Biosciences, Inc. (the “Company”) is a late-stage biopharmaceutical company focused on developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company is initially developing its wholly-owned product candidate, tildacerfont, as the potential first non-steroidal therapy for patients suffering from classic congenital adrenal hyperplasia (“CAH”). The Company is also developing tildacerfont for females suffering from polycystic ovary syndrome. The Company is located in South San Francisco, California and was incorporated in the state of Delaware in April 2016.

Initial Public Offering

In October 2020, the Company consummated its initial public offering (“IPO”) and issued a total of 6,900,000 shares of common stock, which includes 900,000 shares issued pursuant to the exercise of the underwriters’ option to purchase additional shares, at an offering price of $15.00 per share. In aggregate, the Company received net proceeds of $93.4 million, after deducting underwriting discounts and commissions and offering expenses. Upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 15,492,019 shares of common stock.

Private Placement of Common Stock and Warrants

In February 2023, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”) with certain institutional investors (the “Purchasers”), pursuant to which the Company agreed to sell and issue (i) 16,116,000 shares of the Company’s common stock (“Common Stock”), (ii) pre-funded warrants to purchase 800,000 shares of Common Stock (the “Pre-Funded Warrants”) to a Purchaser and (iii) 12,687,000 warrants to purchase Common Stock (the “Standard Warrants” and together with the Pre-Funded Warrants, the “Warrants”) in a private placement transaction (the “Private Placement”). The total gross proceeds to the Company were approximately $53.6 million, which does not include any proceeds that may be received upon exercise of the Standard Warrants.

Open Market Sales Agreement

In February 2022, the U.S. Securities and Exchange Commission (“SEC”) declared effective a registration statement on Form S-3 (the “Shelf Registration”), covering the sale of up to $200.0 million of the Company's securities. Also, in February 2022, the Company entered into an Open Market Sales AgreementSM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) pursuant to which the Company may elect to issue and sell, from time to time, shares of Common Stock having an aggregate offering price of up to $21.0 million under the Shelf Registration through Jefferies acting as the sales agent and/or principal. As of December 31, 2023, the Company has not issued any shares of Common Stock under the Sales Agreement.

Liquidity and Capital Resources

The Company believes that based on its current operating plan, its cash and cash equivalents of $96.3 million as of December 31, 2023 will be sufficient to fund its planned operations and debt obligations for at least 12 months following the issuance date of these financial statements.

The Company has incurred significant losses and negative cash flows from operations. During the year ended December 31, 2023, the Company incurred a net loss of $47.9 million and used $33.3 million of cash in operations. As of December 31, 2023, the Company had an accumulated deficit of $197.2 million and does not expect positive cash flows from operations in the foreseeable future. The Company has funded its operations primarily through the issuance and sale of equity securities, debt and collaboration revenue.

The Company anticipates that it will need to raise substantial additional financing in the future to fund its operations. In order to meet these additional cash requirements, the Company may seek to out-license rights to

develop and commercialize tildacerfont or sell additional equity or issue debt, convertible debt or other securities that may result in dilution to its stockholders. If the Company raises additional funds through the issuance of debt or convertible debt securities, these securities could have rights senior to those of its shares of Common Stock and could contain covenants that restrict its operations. There can be no assurance that the Company will be able to obtain additional equity or debt financing on terms acceptable to it, if at all. Additional debt financing, if available, would result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions such as incurring debt, making capital expenditures or declaring dividends. The Company’s failure to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on its business, results of operations, and financial condition.

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Summary of Stock Option Activity

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Balance as of December 31, 2022		4,166,194		$	3.38		7.7	$	52
Granted		270,000		$	2.26
Exercised		(54	)	$	3.07
Forfeited		(338,764	)	$	4.85
Balance as of December 31, 2023		4,097,376		$	3.19		7.2	$	3,050
Vested and expected to vest as of December 31, 2023		3,972,376		$	3.15		7.2	$	3,050
Vested and exercisable as of December 31, 2023		2,622,154		$	3.13		6.5	$	2,249

Summary of RSU Activity

A summary of the Company’s RSU activity and related information is as follows (in thousands, except share and per share amounts):


	Number of RSUs			Weight-Average Grant Date Fair Value
Balance as of December 31, 2022		1,996,128		$	1.35
Granted		2,375,250		$	2.00
Vested		(484,152	)	$	1.91
Forfeited		(404,563	)	$	2.40
Balance as of December 31, 2023		3,482,663		$	1.59

Summary of Stock-Based Compensation Expense Related to Stock Options, RSUs and ESPP


	Year Ended December 31,
	2023		2022
Research and development	$	1,547	$	929
General and administrative		3,075		2,702
Total stock-based compensation expense	$	4,622	$	3,631

2020 Employee Stock Purchase Plan

Schedule of Weighted-Average Assumptions to Estimate Fair Value of Stock Options and Purchase Rights Under ESPP Using the Black-Scholes Option-Pricing Model

The Company estimated the fair value of stock options and purchase rights under ESPP using the Black-Scholes option-pricing model, with the following weighted-average assumptions:


	2023						2022
	Options			ESPP			Options			ESPP
Expected term (in years)		5.6			1.4			6.0			1.4
Expected volatility		87.8	%		104.6	%		105.4	%		77.2	%
Risk-free interest rate		3.7	%		5.4	%		2.4	%		2.2	%
Expected dividend rate		0.0	%		0.0	%		0.0	%		0.0	%

Subsequent Events

12 Months Ended

Dec. 31, 2023

Subsequent Events [Abstract]

Subsequent Events

14. Subsequent Events

Realignment Plan

On March 10, 2024, the Board of Directors approved a plan to implement cost savings initiatives, including termination of the CAHmelia-203 study and a workforce reduction of approximately 21% (the “Realignment Plan”). The Realignment Plan is effective immediately, with a termination date of March 31, 2024 for affected employees. Affected employees will be offered separation benefits, including severance payments and healthcare coverage assistance.

The final costs, charges and expenditures relating to the Realignment Plan will not be known until all related activities have been completed. The Company estimates that it will incur approximately $0.4 million in cash charges in connection with the Realignment Plan, consisting of expenses related to employee severance payments and healthcare coverage assistance and related costs. The Company expects that the majority of these estimated charges will be recorded in the second quarter of 2024 and that the execution of the Realignment Plan will be substantially complete during the second quarter of 2024.

Equity Grants

In March 2024, the Company granted certain executive officers RSUs underlying approximately 1.2 million shares of Common Stock with time-based and performance-based vesting criteria.

Net Loss Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

13. Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Year Ended December 31,
	2023			2022
Numerator:
Net loss	$	(47,919	)	$	(46,180	)
Denominator:
Weighted-average shares of common stock outstanding		38,510,220			23,527,116
Net loss per share, basic and diluted	$	(1.24	)	$	(1.96	)


	December 31,
	2023		2022
Shares subject to outstanding Standard Warrants		12,687,000		—
Shares subject to outstanding common stock options		4,097,376		4,166,194
Shares subject to outstanding RSUs		3,482,663		1,996,128
Estimated shares issuable under the ESPP		126,151		303,236
Total		20,393,190		6,465,558

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2023	Mar. 14, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Registrant Name	Spruce Biosciences, Inc.
Entity Central Index Key	0001683553
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 75.0
Entity Common Stock, Shares Outstanding		41,149,160
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	SPRB
Security Exchange Name	NASDAQ
Entity File Number	001-39594
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2154263
Entity Address, Address Line One	611 Gateway Boulevard
Entity Address, Address Line Two	Suite 740
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	655-4168
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	Portions of the Registrant’s definitive Proxy Statement for its 2024 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K are incorporated by reference into Part III of this Annual Report on Form 10-K.
Auditor Name	BDO USA, P.C.
Auditor Location	San Jose, California
Auditor Firm ID	243

Leases - Additional Information (Details) - South San Francisco, California $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($) ft²	Dec. 31, 2022 USD ($) ft²
Lessee, Lease, Description [Line Items]
Area of office space \| ft²	6,500	6,500
Operating lease commencement date	2022-12
Operating lease termination date	2028-02
Total minimum rental payments	$ 1,700	$ 1,700
Operating Leases, option to renew lease term description		The Company has an option to extend the lease term of the South San Francisco Lease for an additional three years which has not been included in the lease term as it is not reasonably certain that the Company will exercise this option.
Operating leases, renew lease term	3 years	3 years
letter of credit issued	$ 29	$ 29
Collateralized by a restricted cash deposit	$ 35	$ 35

BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares sold and issued	41,029,832	23,601,004
Common stock, shares outstanding	41,029,832	23,601,004

License Agreements - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2016
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense		$ 49,432,000	$ 35,198,000
Collaboration revenue		10,089,000	0
Deferred revenue		4,911,000	$ 0
Lilly License Agreement \| Eli Lilly and Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense				$ 800,000
Potential additional payment		23,000,000
Research and development arrangement, costs incurred		0
Kaken Pharmaceutical Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payments	$ 15,000,000	15,000,000
Potential additional cash receipt		$ 65,000,000

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Collaboration revenue	$ 10,089	$ 0
Operating expenses:
Research and development	49,432	35,198
General and administrative	12,650	12,085
Total operating expenses	62,082	47,283
Loss from operations	(51,993)	(47,283)
Interest expense	(483)	(420)
Interest and other income, net	4,557	1,523
Net loss	(47,919)	(46,180)
Other comprehensive gain (loss), net of tax:
Unrealized gain (loss) on available for sale securities	558	(374)
Total comprehensive loss	$ (47,361)	$ (46,554)
Net loss per share, basic	$ (1.24)	$ (1.96)
Net loss per share,diluted	$ (1.24)	$ (1.96)
Weighted-average shares of common stock outstanding, basic	38,510,220	23,527,116
Weighted-average shares of common stock outstanding,diluted	38,510,220	23,527,116

Stock-Based Compensation - Schedule of Weighted-Average Assumptions to Estimate Fair Value of Stock Options and Purchase Rights Under ESPP Using the Black-Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	5 years 7 months 6 days	6 years
Expected volatility	87.80%	105.40%
Risk-free interest rate	3.70%	2.40%
Expected dividend rate	0.00%	0.00%
2020 Employee Stock Purchase Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	1 year 4 months 24 days	1 year 4 months 24 days
Expected volatility	104.60%	77.20%
Risk-free interest rate	5.40%	2.20%
Expected dividend rate	0.00%	0.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Leases

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Leases

5. Leases

The Company leases space under a non-cancelable operating lease, which requires the Company to pay base rent, real estate taxes, insurance, general repairs, and maintenance.

In December 2022, the Company entered into a non-cancelable operating lease for approximately 6,500 square feet of office space in South San Francisco, California, which commenced in December 2022 and expires in February 2028 (the “South San Francisco Lease”). Total minimum rental payments for the South San Francisco Lease are $1.7 million over the lease term. The Company has an option to extend the lease term of the South San Francisco Lease for an additional three years which has not been included in the lease term as it is not reasonably certain that the Company will exercise this option. The Company will also be responsible for the payment of additional rent to cover the Company's share of the annual operating and tax expense for the building. Under the terms of the South San Francisco Lease, the Company issued a letter of credit to the landlord of $29 thousand, which is collateralized by a restricted cash deposit of $35 thousand.

Other information related to the operating lease was as follows (dollar amounts in thousands):


	Year Ended December 31,
	2023			2022
Operating lease costs	$	337		$	465
Cash paid for operating lease liabilities	$	251		$	492
Weighted average remaining lease term (years)		4.2			5.2
Weighted average discount rate		8.0	%		8.0	%

Variable lease expense for the years ended December 31, 2023 and 2022 was immaterial.

Future minimum lease commitments under the Company’s leases as of December 31, 2023 were as follows (in thousands):


Year ending December 31,
2024	$	343
2025		354
2026		365
2027		376
2028		64
Total undiscounted lease payments		1,502
Less: present value discount		(232	)
Total lease liabilities	$	1,270
Lease liabilities, current portion*	$	251
Lease liabilities, net of current portion		1,019
Total lease liabilities	$	1,270

* included in accrued expenses and other current liabilities on the balance sheets

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Income tax expense	$ 0	$ 0
Increase in net valuation allowance	16,800,000	17,000,000
Unrecognized tax benefits	3,240,000	2,959,000	$ 1,589,000
Income tax penalties or interest	0	$ 0
Federal
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 118,200,000			$ 111,000,000
Net operating loss carryforwards expiration year	2036
Federal \| General Business Tax Credit Carryforward
Income Tax Disclosure [Line Items]
Tax credit carryforward, amount	$ 22,200,000
Tax credit carryforward expiration year	2036
State
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 123,000,000
Net operating loss carryforwards expiration year	2036
State \| Research and Development Tax Credit Carry Forwards
Income Tax Disclosure [Line Items]
Tax credit carryforward, amount	$ 1,700,000

Capital Structure

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Capital Structure

9. Capital Structure

Common Stock

As of December 31, 2023 and 2022, the Company was authorized to issue 200,000,000 shares of $0.0001 par value common stock, respectively. Holders of the Company’s common stock are entitled to dividends if and when declared by the Board of Directors of the Company (“Board of Directors”). The holder of each share of common stock is entitled to one vote. As of December 31, 2023, no dividends were declared.

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	December 31,
	2023		2022
Common Stock warrants, issued and outstanding		12,687,000		—
Stock options, issued and outstanding		4,097,376		4,166,194
Restricted and performance stock units, issued and outstanding		3,482,663		1,996,128
Shares available for future issuance under 2020 Equity Incentive Plan		77,631		940,061
Shares available for future issuance under 2020 Employee Stock Purchase Plan		675,038		601,819
Total shares reserved		21,019,708		7,704,202

- Definition

The entire disclosure for equity.

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+ Details

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Numerator:
Net loss	$ (47,919)	$ (46,180)
Denominator:
Weighted-average shares of common stock outstanding, basic	38,510,220	23,527,116
Weighted-average shares of common stock outstanding,diluted	38,510,220	23,527,116
Net loss per share, basic	$ (1.24)	$ (1.96)
Net loss per share,diluted	$ (1.24)	$ (1.96)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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-Name Accounting Standards Codification
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-Paragraph 1
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-Publisher FASB
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 22: http://www.xbrl.org/2003/role/disclosureRef
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Reference 23: http://www.xbrl.org/2003/role/disclosureRef
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Reference 27: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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Reference 29: http://www.xbrl.org/2003/role/disclosureRef
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 31: http://www.xbrl.org/2003/role/disclosureRef
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Reference 32: http://www.xbrl.org/2003/role/exampleRef
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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
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Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Leases (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Other Information Related to Operating Leases

Other information related to the operating lease was as follows (dollar amounts in thousands):


	Year Ended December 31,
	2023			2022
Operating lease costs	$	337		$	465
Cash paid for operating lease liabilities	$	251		$	492
Weighted average remaining lease term (years)		4.2			5.2
Weighted average discount rate		8.0	%		8.0	%

Future Minimum Annual Lease Commitments Under Non-cancelable Operating Leases

Future minimum lease commitments under the Company’s leases as of December 31, 2023 were as follows (in thousands):


Year ending December 31,
2024	$	343
2025		354
2026		365
2027		376
2028		64
Total undiscounted lease payments		1,502
Less: present value discount		(232	)
Total lease liabilities	$	1,270
Lease liabilities, current portion*	$	251
Lease liabilities, net of current portion		1,019
Total lease liabilities	$	1,270

* included in accrued expenses and other current liabilities on the balance sheets

Fair Value Measurements - Summary of Investments in an Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, less than twelve months	$ 16,743
Gross unrealized losses, less than twelve months	(77)
Fair value, twelve months or greater	34,911
Gross unrealized losses, twelve months or greater	(482)
Fair value, total	51,654
Gross unrealized losses, total	(559)
U.S. government treasury securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, less than twelve months	16,743
Gross unrealized losses, less than twelve months	(77)
Fair value, twelve months or greater	23,585
Gross unrealized losses, twelve months or greater	(439)
Fair value, total	40,328
Gross unrealized losses, total	(516)
Corporate bonds
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair value, less than twelve months	0
Gross unrealized losses, less than twelve months	0
Fair value, twelve months or greater	11,326
Gross unrealized losses, twelve months or greater	(43)
Fair value, total	11,326
Gross unrealized losses, total	$ (43)

Term Loan

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Term Loan

6. Term Loan

In September 2019, the Company entered into a Loan and Security Agreement, as subsequently amended (the “Loan Agreement”) with Silicon Valley Bank (“SVB”) providing for a term loan (the “Term Loan”) for an aggregate principal amount of $4.5 million.

In September 2019 and in connection with the Loan Agreement, the Company issued a warrant to purchase up to an aggregate of 49,609 shares of Common Stock at $1.44 per share. The Company determined the initial fair value of the warrant to be $0.1 million using the Black-Scholes option-pricing model. The fair value of the warrant was recorded to equity and as a debt discount, which was being amortized to interest expense using the effective interest method over the term of the Term Loan. In November 2020, the warrant was net-exercised for 46,358 shares of Common Stock.

In March 2021, the Company entered into a First Amendment to Loan and Security Agreement (the “First Amendment”), which increased the aggregate principal amount of the Term Loan to $30.0 million, of which $20.0 million was immediately available under the first tranche (“First Tranche”) and $10.0 million was available under the second tranche through December 31, 2022 (“Second Tranche”), subject to the completion of certain clinical or financial milestones. Pursuant to the First Amendment, the Term Loan will mature on January 1, 2026 (the “Maturity Date”).

In May 2022, the Company entered into a Second Amendment to Loan and Security Agreement (the “Second Amendment”), which amended the milestones for the Second Tranche, added a liquidity covenant for the Second Tranche and amended the interest and prepayment terms.

As of December 31, 2023, the carrying value of the Term Loan was $3.3 million, consisting of the outstanding principal under the First Tranche of $3.4 million, less unamortized debt discount and issuance costs of $39 thousand which are being amortized using the effective interest method over the life of the Term Loan. Commitments available under the Second Tranche of $10.0 million expired on December 31, 2022.

The Loan Agreement provided for monthly cash interest-only payments following the funding date of each respective tranche and continuing thereafter through December 31, 2022. The Term Loan is subject to a floating per annum interest rate equal to the greater of (a) 0.50% above the Prime Rate (as defined in the Loan Agreement) or (b) 3.75%. Following the interest-only period, the outstanding Term Loan balance is payable in (i) 37 consecutive monthly payments after the end of the interest-only period and continuing on the same day of each month thereafter, in amounts that would fully amortize such Term Loan balance, as of the first business day of the first month following the amended interest-only period, over the repayment period, plus (ii) monthly payments of accrued but unpaid interest. As of December 31, 2023 and 2022, the stated interest rate of the Term Loan was 9.0% and 8.0%, respectively.

The final payment is due on the Maturity Date and includes all outstanding principal plus accrued unpaid interest and an end of term payment totaling $0.3 million, which is 6.0% of the original funded principal amount of the First Tranche (the “Supplemental Final Payment”). The Company may prepay amounts outstanding under the Term Loan at any time provided certain notification conditions are met, in which case, all outstanding principal plus accrued and unpaid interest, the Supplemental Final Payment, a prepayment fee of 1% or 2% of the principal amount of the First Tranche, and any bank expenses become due and payable.

The Company is subject to customary affirmative and restrictive covenants under the Loan Agreement. The Company’s obligations under the Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than intellectual property. The Company also agreed not to encumber its intellectual property assets, except as permitted by the Loan Agreement.

The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations under the Loan Agreement and the occurrence of a material adverse change in its business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the lender would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement. As of December 31, 2023, the Company was in compliance with all covenants under the Loan Agreement and there has been no material adverse change.

As of December 31, 2023, future payments of principal and interest are as follows (in thousands):


Year ending December 31,
2024	$	1,863
2025		1,714
2026		136
Total	$	3,713
Less: interest		(335	)
Term loan, gross	$	3,378
Less: unamortized debt issuance costs		(39	)
Less: term loan, current portion		(1,622	)
Term loan, net of current portion	$	1,717

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

7. Commitments and Contingencies

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business. The Company evaluates the likelihood of an unfavorable outcome in legal or regulatory proceedings to which it is a party and records a loss contingency on an undiscounted basis when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These judgments are subjective and based on the status of such legal proceedings, the merits of the Company’s defenses, and consultation with legal counsel. Actual outcomes of these legal proceedings may differ materially from the Company’s estimates. The Company estimates accruals for legal expenses when incurred as of each balance sheet date based on the facts and circumstances known to the Company at that time.

Legal Matters

The Company’s industry is characterized by frequent claims and litigation, including claims regarding intellectual property. As a result, the Company may be subject to various legal proceedings from time to time. The results of any future litigation cannot be predicted with certainty, and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. The Company was not subject to any material legal proceedings during the years ended December 31, 2023 and 2022 and management is not aware of any pending or threatened litigation.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Risks and Uncertainties

Concentration of Credit Risk

Segment Reporting

Cash and Cash Equivalents

Restricted Cash

Fair Value of Financial Instruments

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

▪

Level 1—Quoted prices in active markets for identical assets and liabilities;

▪

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Investments

Leases

Property and Equipment, Net

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Furniture and fixtures	5 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years

Long-Lived Assets

Accrued Research and Development Expenses

Revenue Recognition

Research and Development Expenses

Stock-Based Compensation

▪

Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury constant maturity rates with remaining terms similar to the expected term of the options.

▪

Forfeitures. The Company accounts for forfeitures as they occur.

The fair value of RSUs, including RSUs subject to performance-based vesting conditions, is based on the grant-date fair value of the Company's stock price.

Income Taxes

underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits.

Comprehensive Loss

Comprehensive loss

Net Loss per Share

Emerging Growth Company Status

Recently Accounting Pronouncements Adopted

Recent Accounting Pronouncements Adopted

Recent Accounting Pronouncements - Not Yet Adopted

Stock-Based Compensation - Summary of RSU Activity (Details) - RSU - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares, Unvested, Beginning Balance	1,996,128
Shares, Granted	2,375,250
Shares, Vested	(484,152)
Shares, Forfeited	(404,563)
Shares, Unvested, Ending Balance	3,482,663	1,996,128
Weighted Average Grant Date Fair Value Per Share, Beginning Balance	$ 1.35
Weighted Average Grant Date Fair Value Per Share, Granted	2	$ 1.24
Weighted Average Grant Date Fair Value Per Share, Vested	1.91
Weighted Average Grant Date Fair Value Per Share, Forfeited	2.4
Weighted Average Grant Date Fair Value Per Share, Ending Balance	$ 1.59	$ 1.35

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2023

Balance Sheet Components Disclosure [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2023		2022
Accrued research and development expenses	$	10,832	$	7,449
Accrued compensation and benefits		3,101		1,286
Accrued general and administrative expenses		416		525
Lease liabilities, current portion		251		139
Total accrued expenses and other current liabilities	$	14,600	$	9,399

Leases - Future Minimum Annual Lease Commitments under Non-cancelable Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 343
2025	354
2026	365
2027	376
2028	64
Total undiscounted operating lease payments	1,502
Less: present value discount	(232)
Total operating lease liability	1,270
Lease liabilities, current portion	$ 251
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other current liabilities
Operating lease liability, net of current portion	$ 1,019	$ 1,261

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		$ 77,644
Gross Unrealized Gains		1
Gross Unrealized Losses		(559)
Fair Value		77,086
Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		55,148
Gross Unrealized Gains		1
Gross Unrealized Losses		(559)
Fair Value		54,590
Cash And Cash Equivalent Member
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	$ 95,875	22,496
Fair Value	95,875	22,496
Level 1 \| Money Market Fund Member
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	95,875	22,496
Fair Value	$ 95,875	22,496
Level 1 \| U.S. government treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		43,779
Gross Unrealized Gains		1
Gross Unrealized Losses		(516)
Fair Value		43,264
Level 2 \| Short Term Debt Corporate Bond Securities Member
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost		11,369
Gross Unrealized Losses		(43)
Fair Value		$ 11,326

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Balance Sheet Components Disclosure [Abstract]
Accrued research and development expenses	$ 10,832	$ 7,449
Accrued compensation and benefits	3,101	1,286
Accrued general and administrative expenses	416	525
Lease liabilities, current portion	251	139
Total accrued expenses and other current liabilities	$ 14,600	$ 9,399

License Agreements

12 Months Ended

Dec. 31, 2023

Research and Development [Abstract]

License Agreements

8. License Agreements

Eli Lily and Company

In May 2016, the Company entered into a license agreement (the “Lilly License Agreement”), with Eli Lilly and Company (“Lilly”). Pursuant to the terms of the Lilly License Agreement, Lilly granted the Company an exclusive, worldwide, royalty bearing, sublicensable license under certain technology, patent rights, know-how and proprietary materials related to certain compounds, to research, develop, and commercialize such compounds for all pharmaceutical uses.

As partial consideration for the rights granted to the Company under the Lilly License Agreement, the Company made a one-time upfront payment to Lilly of $0.8 million during the year ended December 31, 2016, which was recorded as research and development expense as there was no alternative use due to the early stage of the technology. The Company is also required to pay Lilly up to an aggregate of $23.0 million upon the achievement, during the time the Lilly License Agreement remains in effect, of certain milestones relating to the clinical development and commercial sales of products licensed under the Lilly License Agreement. Such payments are for predetermined fixed amounts, are paid only upon the first occurrence of each event, and are due shortly after achieving the applicable milestone. In addition, the Company is required to pay Lilly tiered royalties on annual worldwide net sales with rates ranging from mid-single-digits to sub-teens. No additional amounts were paid by the Company to Lilly during any of the periods presented, nor were due as of such dates pursuant to the Lilly License Agreement.

The Lilly License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until the later of (i) the tenth anniversary of the date of first commercial sale in such country, (ii) the expiration in such country of the last-to-expire licensed patent having a valid claim covering the manufacture, use or sale of the licensed product as commercialized in such country, and (iii) the expiration of any data or regulatory exclusivity period for the licensed product in such country.

Kaken Pharmaceutical Co, Ltd.

On January 5, 2023, the Company entered into a collaboration and license agreement (the “Kaken License Agreement”) with Kaken Pharmaceutical Co, Ltd. (“Kaken”). Under the terms of the Kaken License Agreement, the Company granted to Kaken the exclusive right to develop, manufacture and commercialize the Company’s product candidate, tildacerfont, for the treatment of CAH in Japan. Pursuant to the Kaken License Agreement, Kaken will be responsible for securing and maintaining regulatory approvals necessary to commercialize tildacerfont in Japan. The Company will retain all rights to tildacerfont in all other geographies.

Pursuant to the Kaken License Agreement, Kaken made an upfront payment to the Company of $15.0 million in April 2023. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of approximately $65.0 million (at exchange rates in effect on the date of the Kaken License Agreement) upon the achievement of specified milestones related to the development, regulatory approval and commercialization of tildacerfont in Japan, including the achievement of specified net sales thresholds, if approved. Kaken has agreed to pay the Company a non-creditable, non-refundable specified purchase price for each unit of Company-manufactured product supplied to Kaken for commercial sale. In addition, the Company will also be entitled to receive a royalty for each unit of non-Company manufactured product sold equal to a range of double-digit percentages up to the mid-twenties based on annual net sales of tildacerfont in Japan. Both the purchase price for each unit and the royalty rate are subject to reduction in certain circumstances as specified in the Kaken License Agreement. Kaken’s obligation to pay royalties will continue for ten years after the first commercial sale in Japan or, if later, until the expiration of regulatory exclusivity of tildacerfont or the expiration of the last valid claim of a Company-licensed patent covering tildacerfont in Japan.

The Company identified a combined performance obligation consisting of the license and know-how granted to Kaken as well as certain non-contingent research and development activities. The Company determined that the transaction price at the inception of the Kaken License Agreement consisted of the upfront payment of $15.0 million. The transaction price is recognized as revenue using the cost-based input method over the estimated period of its non-contingent research and development obligations, which is approximately two years.

During the year ended December 31, 2023, the Company recognized $10.1 million as collaboration revenue, all of which related to activities satisfied in the current period. As of December 31, 2023, deferred revenue was $4.9 million, all of which was current.