Summary of significant accounting policies

12 Months Ended

Dec. 31, 2023

Summary of significant accounting policies

Summary of significant accounting policies

2. Summary of significant accounting policies

Basis of presentation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted, or GAAP, in the United States. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Updates, or ASU, promulgated by the Financial Accounting Standards Board, or FASB.

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

Use of estimates

The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the expected volatility used to estimate fair value of stock options, accrued research and development expenses, the fair value of acquired in-process research and development assets, and the estimated costs which drive the revenue recognition for the Collaboration Agreement with AbbVie. Estimates and assumptions are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from these estimates.

Segment and geographic information

Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or CODM, or decision-making group, in deciding how to allocate resources and in assessing performance. The CODM is the Company’s Chief Executive Officer. The Company views its operations as and manages its business in one operating segment operating exclusively in the United States.

Cash and cash equivalents

Cash and cash equivalents consist of standard checking accounts, a money market account and three-month treasury bills. The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents.

Restricted cash

Restricted cash represents collateral provided for a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate facilities. Cash will be released from restriction upon termination of the lease. Restricted cash was $100,000 at both December 31, 2023 and 2022, respectively. The following table provides a reconciliation of the components of cash and cash equivalents and restricted cash presented in the consolidated statements of cash flows:

(in thousands)	December 31, 2023		December 31, 2022
Cash and cash equivalents	$	98,679	$	20,323
Restricted cash		100		100
	$	98,779	$	20,423

Marketable Securities

The Company’s marketable securities consist of investments in U.S. Treasury debt securities. Debt securities are classified as available-for-sale and are carried at fair value with the unrealized gains and losses, net of tax, included in accumulated other comprehensive income, a component of stockholders’ equity. These debt securities have an original maturity period greater than 90 days, but less than one year. The Company classifies marketable securities that are available for use in current operations as current assets on the consolidated balance sheets. Unrealized losses are evaluated for impairment under ASC 326, Financial Instruments - Credit Losses, or ASC 326, to determine if the impairment is credit-related or non-credit-related. Credit-related impairment is recognized as an allowance on the consolidated balance sheet with a corresponding adjustment to earnings, and non-credit-related impairment is recognized in accumulated other comprehensive loss.

Concentration of credit risk

Financial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash and cash equivalents and marketable securities. The Company maintains deposits in a financial institution in excess of government insured limits. Management believes that the Company is not exposed to significant credit risk as the Company’s deposits are held at a financial institution that management believes to be of high credit quality, and the Company has not experienced any losses on these deposits. Management also believes that the Company is not exposed to significant credit risk as it relates to marketable securities because the Company only invests in U.S government securities.

Property and equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows:

Asset category	Estimates useful life
Lab equipment	5 years
Leasehold improvements	Lesser of lease term or 5 years
Computer equipment	3 years
Office equipment	5 years
Furniture and fixtures	5 years

Expenditures for repairs and maintenance of assets are charged to expense as incurred, while major betterments are capitalized. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts and any resulting gain or loss is included in the consolidated statements of operations and comprehensive loss.

Asset Acquisitions

Acquisitions of assets or a group of assets that do not meet the definition of a business are accounted for as asset acquisitions, with a cost accumulation model used to determine the cost of the acquisition. Common stock issued as consideration in an acquisition of assets is generally measured based on the acquisition date fair value of the equity interests issued. Direct transaction costs are recognized as part of the cost of an acquisition of assets. Intangible assets that are acquired in an asset acquisition for use in research and development activities that have an alternative future use are capitalized as in-process research and development, or IPR&D. Acquired IPR&D that has no alternative future use is expensed immediately in the consolidated statements of operations and comprehensive loss. For further disclosures related to asset acquisitions see Note 3 to the consolidated financial statements.

Impairment of long-lived assets

The Company evaluates its long-lived assets, which consist primarily of property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There were no impairment losses recognized during the years ended December 31, 2023 and 2022.

Equity issuance costs

The Company capitalizes costs directly associated with equity financings as deferred offering costs on its consolidated balance sheet. These costs remain capitalized until such financings are consummated, at which time such costs are recorded against the gross proceeds from the applicable financing. If a financing is abandoned, deferred offering costs are expensed.

As of December 31, 2022, there were $0.3 million of deferred offering costs related to the Open Market Sale Agreement, or the ATM Agreement, and shelf registration that were expensed in 2023 as a result of the termination of the ATM Agreement. There were no deferred offering costs as of December 31, 2023.

Government assistance programs

The Company accounts for amounts received under its DoD expense reimbursement contract as contra-research and development expenses in the consolidated statements of operations and comprehensive loss.

Collaboration revenue

The Company evaluates its collaborative arrangements pursuant to ASC 808, Collaborative Arrangements, or ASC 808, and ASC 606, Revenue from Contracts with Customers, or ASC 606. The Company considers the nature and contractual terms of collaborative arrangements and assesses whether the arrangement involves a joint operating activity pursuant to which the Company is an active participant and is exposed to significant risks and rewards with respect to the arrangement. If the Company is an active participant and is exposed to significant risks and rewards with respect to the arrangement, the Company accounts for the arrangement as a collaboration under ASC 808. If it is not exposed to significant risks and rewards and the contract is with a customer, the Company accounts for the collaboration under ASC 606.

Payments pursuant to collaborative arrangements may include non-refundable upfront payments, research option and license option payments, milestone payments upon the achievement of significant regulatory and development events, commercial sales milestones, and royalties on product sales. The amount of variable consideration is constrained until it is probable that the revenue is not at a significant risk of reversal in a future period.

In determining the appropriate amount of revenue to be recognized as the Company fulfills its obligations under a collaboration arrangement, the Company applies the five-step model of ASC 606: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract, including whether they are capable of being distinct; (iii) determine the transaction price, including the constraint on variable consideration; (iv) allocate the transaction price to the performance obligations; and (v) recognize revenue when (or as) the entity satisfies a performance obligation.

The Company applies significant judgment when evaluating whether contractual obligations represent distinct performance obligations, allocating transaction price to performance obligations within a contract, determining when performance obligations have been met, and assessing the recognition of variable consideration. When consideration is received prior to the Company completing its performance obligation under the terms of a contract, a contract liability is recorded as deferred revenue. Deferred revenue expected to be recognized as revenue within the twelve months following the balance sheet date is classified as a current liability.

In January 2023, the Company entered into the Collaboration Agreement with AbbVie, which was determined to be within the scope of ASC 606. Please see Note 4 for further information related to the accounting for the Collaboration Agreement.

Research and development expenses

Research and development costs are charged to expense as incurred. Research and development costs consist of costs incurred in performing research and development activities, including salaries and bonuses, share-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation and amortization, preclinical and clinical development expenses, including manufacture and testing of clinical supplies, consulting and other contracted services. Additionally, under the terms of the license agreements described in Note 10, the Company is obligated to make future payments should certain development, regulatory, and sales milestones be achieved. Costs for certain research and development activities are recognized based on the terms of the individual arrangements, which may differ from the timing of receipt of invoices and payment of invoices and are reflected in the financial statements as a prepaid or accrued expense.

Share-based compensation

The Company’s share-based compensation program allows for grants of stock options and restricted stock awards. Grants are awarded to employees and non-employees, including directors.

The Company accounts for its share-based compensation awards granted to employees and non-employees based on the estimated fair value on the date of grant and recognized compensation expense of those awards over the requisite service period, which is the vesting period of the respective award. The Company accounts for forfeitures as they occur. For share-based awards with service-based vesting conditions, the Company recognized compensation expense on a

straight-line basis over the service period. The Company classified share-based compensation expense in its statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified.

The Company estimates the fair value of options granted using the Black-Scholes option pricing model for stock option grants to both employees and non-employees. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (i) the expected stock price volatility, (ii) the expected term of the award, (iii) the risk-free interest rate and (iv) expected dividends. Due to the lack of Company-specific historical and implied volatility data, the Company has based its computation of expected volatility on the historical volatility of a representative group of public companies with similar characteristics to the Company, including stage of product development and biopharmaceutical industry focus. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The Company uses the simplified method to calculate the expected term for options granted to employees and non-employees whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the options due to its lack of sufficient historical data. The risk-free interest rate is based on U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. The exercise price is the fair value of the common stock as of the measurement date.

Patent costs

All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss.

Leases

The Company accounts for leases in accordance with ASC 842, Leases. At the inception of an arrangement, the Company determines whether an arrangement contains a lease based on facts and circumstances present in the arrangement. An arrangement is or contains a lease if the arrangement conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Typically, lessees are required to recognize leases with a term greater than one year on the consolidated balance sheets as an operating or finance lease liability and right-of-use asset. Right-of-use assets represent the Company’s right to use an underlying asset during the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. The Company has elected the practical expedient to not recognize leases with a term of 12 months or less. The Company does not have any financing leases as of December 31, 2023.

Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the remaining lease term. Options to extend the lease term are included in the Company’s assessment of the lease term only if there is a reasonable assessment that the Company will renew. Lease payments are discounted to their present value using either the interest rate implicit in the lease or the Company’s incremental borrowing rate, which reflects the fixed rate in which the Company could borrow on a collateralized basis the amount of lease payments in the same currency, for a similar term, in a similar economic environment.

Income taxes

The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and tax returns. Deferred tax assets and liabilities are determined based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards, using enacted tax rates expected to be in effect in the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that these assets may not be realized. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that

meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for income taxes.

Fair value of financial instruments

ASC Topic 820, Fair Value Measurement (ASC 820), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the assets or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the price that would be received to sell an asset or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tiered value hierarchy that distinguishes between the following:

● Level 1: Quoted market prices in active markets for identical assets or liabilities.

● Level 2: Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves.

● Level 3: Unobservable inputs for the asset or liability (i.e., supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk).

To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

In accordance with the fair value hierarchy described above, the following tables set forth the Company’s assets and liabilities measured at fair value on a recurring basis:

	Level 1		Level 2		Level 3		Total Fair Value
December 31, 2023
Assets:
Cash equivalents – money market funds	$	73,988	$	—	$	—	$	73,988
Cash equivalents – short-term U.S. Treasury securities		—		22,993		—		22,993
Marketable securities – U.S. Treasury securities		—		39,463		—		39,463
Total	$	73,988	$	62,456	$	—	$	136,444
December 31, 2022
Assets:
Cash equivalents – money market funds	$	20,013	$	—	$	—	$	20,013

The Company’s marketable securities consist of U.S. Treasury debt securities with a contractual maturity date of 6 months. The following is a summary of available-for-sale marketable securities which provides a reconciliation of historical cost basis to fair value as of December 31, 2023, including cumulative unrealized gains and losses.

		Amortized Cost		Unrealized Gain		Unrealized Loss		Fair Value
December 31, 2023
U.S. Treasury securities	$	39,441	$	22	$	—	$	39,463

Net loss per share

Basic net loss per share of common stock is computed by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period. Diluted net loss per share of common stock is computed by adjusting net loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share of common stock is computed by dividing the diluted net loss by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents.

The following potentially dilutive securities outstanding as of December 31, 2023 and 2022 have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive:

	Year ended December 31,
	2023	2022
Stock options(1)	7,978,291	2,519,405
Common stock warrants(1)	500,000	1,303,112
	8,478,291	3,822,517

(1) Represents common stock equivalents

In periods in which the Company reports a net loss per share of common stock, diluted net loss per share of common stock is the same as basic net loss per share of common stock since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss per share of common stock for the years ended December 31, 2023 and 2022.

Recently adopted accounting standards

ASU 2016-13, Credit Losses

On January 1, 2023, we adopted ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. This standard amended the guidance on the recognition of impairment losses of certain financial instruments. The ASU established the current expected credit loss model, which is based on expected losses rather than incurred losses. Adoption of this standard had no impact on our consolidated financial statements.

Recent accounting standards not yet adopted

ASU 2023-09, Income Tax Disclosures

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which updates income tax disclosures primarily related to the rate reconciliation and income taxes paid information. This update also includes certain other amendments to improve the effectiveness of income tax disclosures. The amendments in this update are effective for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. The Company is still in the process of determining the effect this ASU will have on the consolidated financial statements.