Artiva Biotherapeutics, Inc.

1. Organization, Liquidity and Basis of Presentation

Organization

Artiva Biotherapeutics, Inc. (the Company) was incorporated in the State of Delaware on February 14, 2019. The Company is a biopharmaceutical company focused on developing off-the-shelf, allogeneic, natural killer (NK) cell-based therapies that are effective, safe and accessible for patients with devastating autoimmune diseases and cancers.

From its inception to December 31, 2025, the Company has devoted substantially all of its resources to organizing and staffing the Company, business planning, raising capital, establishing and engaging in collaborations, performing research and development, advancing and scaling up product candidate manufacturing, establishing cold chain delivery logistics, establishing and protecting its intellectual property portfolio, and providing general and administrative support for these activities.

Reverse Stock Split

On July 12, 2024, the Company effected a 1-for-4.386 reverse stock split of its common stock and convertible preferred stock. The par value and the authorized shares of the common stock and convertible preferred stock were not adjusted as a result of the reverse stock split. These accompanying financial statements and notes to the financial statements give retroactive effect to the reverse stock split for all periods presented.

Initial Public Offering

On July 22, 2024, the Company completed its Initial Public Offering (the IPO), pursuant to which it issued and sold 13,920,000 shares of common stock at a public offering price of $12.00 per share. The aggregate gross proceeds of the IPO were $167.0 million before underwriter discounts and commissions, fees, and expenses of $15.9 million, for net proceeds from the IPO of $151.1 million. On July 25, 2024, the underwriters partially exercised their 30-day option and purchased an additional 1,000,000 shares of the Company’s common stock at the IPO price, upon which the Company received additional gross proceeds of $12.0 million before commissions of $0.8 million, for net proceeds of approximately $11.2 million. The aggregate net proceeds of the IPO was $162.3 million (the IPO Proceeds). All underwriter discounts and commissions, fees, and expenses, including deferred offering costs have been charged to additional paid-in capital as recorded against the gross proceeds.

Liquidity

The Company has incurred net losses and negative cash flows from operations since inception, has a significant accumulated deficit and expects to continue to incur net losses for the foreseeable future. The Company has never generated any revenue from product sales and does not expect to generate any revenues from product sales unless and until it successfully completes development of and obtains regulatory approval for its product candidates, which will not be for several years, if ever. The Company has an accumulated deficit of $330.5 million as of December 31, 2025. During the year ended December 31, 2025, the Company used $76.8 million of cash for operating activities. As of December 31, 2025, the Company has $108.0 million in cash, cash equivalents and investments. From inception through December 31, 2025, the Company has raised aggregate gross proceeds of$441.7 million to fund operations, comprised primarily of proceeds received from the IPO, including proceeds from the underwriters’ partial exercise of their purchase option, issuances of convertible promissory notes, simple agreements for future equity (SAFEs), private placements of convertible preferred stock, and funds received from collaboration arrangements.

While the Company does anticipate its cash runway to end in the second quarter of 2027, the Company believes its existing cash, cash equivalents and investments will be sufficient to fund planned operations for at least one year from the issuance of these financial statements. The Company will need to secure additional funding in the future in order to carry out all of the Company’s planned research and development activities and regulatory activities, conduct any substantial additional development requirements requested by the FDA, and commercialize product candidates. If the Company is unable to obtain additional funding, the Company will be forced to delay, reduce or eliminate some or all of its research and development programs, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue plans to obtain additional funding before achieving sufficient profitability and positive cash flows from operations, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

Basis of Presentation

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

2. Summary of Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the financial statements include: the accrual of research and development expenses, common stock, stock-based compensation, SAFEs and operating lease liabilities. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions.

Concentration of Credit Risk

Financial instruments which potentially subject the Company to significant concentration of credit risk consist of cash, cash equivalents, and investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts, and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

Allowance for Credit Losses

For investments in an unrealized loss position, the Company first assesses whether it intends to sell, or is more likely than not that it will be required to sell, the investment before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the investment’s amortized cost basis is written down to fair value through earnings. For investments that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the extent to which fair value is less than amortized cost, any changes in interest rates, and any changes to the rating of the security by a rating agency, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security is compared to the amortized cost basis of the investment. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive loss.

Fair Value of Financial Instruments

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

Level 1– Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

Level 2– Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability.

Level 3– Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

Investments

The Company holds investments in commercial paper, government and government agency bonds, and corporate debt obligations. The Company has classified its investment securities as current assets in the balance sheets because these are considered highly liquid securities and are available for use in current operations. All investments are accounted for as available-for-sale because these investment securities are considered available for use in operations. The Company carries these securities at fair value and reports unrealized gains and losses as a separate component of accumulated other comprehensive income. The cost of debt securities is adjusted for amortization of purchase premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income, net in the statements of operations and comprehensive loss. Realized gains and losses on sales of securities are determined using the specific identification method and recorded in other income, net in the statements of operations and comprehensive loss.

As of December 31, 2025 and 2024, accrued interest receivables on investments were$0.7 million and $0.9 million, respectively, and are included inprepaid expenses and other current assets in the Company’s balance sheets. The Company does not measure an allowance for credit losses for accrued interest receivables. For the purposes of identifying and measuring an impairment, accrued interest is excluded from both the fair value and amortized cost basis of the investment. Uncollectible accrued interest receivables associated with an impaired debt security are reversed against interest income upon identification of the impairment. No accrued interest receivables were written off during the years ended December 31, 2025 and 2024.

Cash and Cash Equivalents

Cash and cash equivalents include cash in readily available operating accounts, money market funds, and government bonds. 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 is comprised of cash that is restricted as to withdrawal or use under the terms of certain contractual agreements. Restricted cash as of December 31, 2025 and 2024, was$0.5 million and $0.3 million, respectively, consisting of collateral for letters of credit related to the Company’s lease agreementsand funds to support the Company’s cash secured credit card program, and is included in non-current assets in the balance sheets.

Property and Equipment, Net

Property and equipment, net isstated at cost and depreciated using the straight-line method over the estimated useful lives of the assets (generallytwoto five years). The Company capitalizes laboratory equipment used for research and development if it has alternative future use in research and development or otherwise. Upon retirement or sale, the cost of assets disposed and the related accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in loss from operations. Leasehold improvements are stated at cost and depreciated over the shorter of the estimated useful life or remaining lease term.

Impairment of Long-Lived Assets

The Company accounts for the impairment of long-lived assets by reviewing these assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted-cash-flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. The Company didnot recognize impairment losses for the years ended December 31, 2025 or 2024.

Research and Development Expenses and Accrued Research and Development Costs

Research and development expenses include costs to third-party contractors to perform research and development activities, internal related salaries, benefits, stock-based compensation charges for those individuals involved in research and development efforts, and associated overhead expenses. Research and development costs are expensed as incurred.

The Company is required to estimate its expenses resulting from its obligations under contracts with vendors, consultants, and contract research organizations, in connection with conducting research and development activities. 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 under such contracts. The Company reflects research and development expenses in its financial statements by matching those expenses with the period in which services and efforts are expended, as measured by the timing of various aspects of the preclinical or clinical study or related activities. The Company determines accrual estimates through review of the underlying contracts along with preparation of financial models taking into account discussions with research and other key personnel as to the progress of studies, or other services being conducted. As of December 31, 2025, the Company has had no material differences between its estimates of such expenses and the amounts actually incurred. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed, or services are performed, or when it is no longer expected that the goods will be delivered, or the services rendered.

Licenses

Upfront payments and other consideration under license agreements are expensed as research and development expense upon receipt of the license, and annual maintenance fees under license agreements are expensed in the period in which they are incurred.

Certain license agreements include milestone payments which are recognized when it becomes probable that the achievement of certain milestones will be met. The Company records this expense as research and development expense in its statements of operations and comprehensive loss.

Patent Costs

The Company expenses all costs as incurred in connection with patent applications (including direct application fees, and the legal and consulting expenses related to making such applications) and such costs are included in general and administrative expenses in the statements of operations and comprehensive loss.

Leases

At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use (ROU) asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. The Company additionally evaluates leases at their inception to determine if they are to be accounted for as an operating lease or a finance lease. A lease is accounted for as a finance lease if it meets one of the following five criteria: the lease has a purchase option that is reasonably certain of being exercised, the present value of the future cash flows is substantially all of the fair market value of the underlying asset, the lease term is for a significant portion of the remaining economic life of the underlying asset, the title to the underlying asset transfers at the end of the lease term, or if the underlying asset is of such a specialized nature that it is expected to have no alternative uses to the lessor at the end of the term.

Leases that do not meet the finance lease criteria are accounted for as operating leases. Operating lease assets represent a right to use an underlying asset for the lease term and operating lease liabilities represent an obligation to make lease payments arising from the lease. Operating lease liabilities with a term greater than one year and their corresponding ROU assets are recognized in the balance sheets at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain adjustments to the ROU asset may be required for items such as initial direct costs paid or incentives received. As the Company’s leases do not typically provide an implicit rate, the Company utilizes the appropriate incremental borrowing rate, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Lease cost is recognized on a straight-line basis over the lease term and variable lease payments are recognized as operating expenses in the period in which the obligation for those payments is incurred. Variable lease payments primarily include common area maintenance, utilities, real estate taxes, insurance, and other operating costs that are passed on from the lessor in proportion to the space leased by the Company. The Company has elected the practical expedient to not separate between lease and non-lease components.

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

The fair value of stock options is estimated using a Black-Scholes valuation model on the date of grant. This method requires certain assumptions be used as inputs, such as the fair value of the underlying common stock, expected term of the option before exercise, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. Options granted have a maximum contractual term of 10 years. The Company has limited historical stock option activity and therefore estimates the expected term of stock options granted using the simplified method, which represents the arithmetic average of the original contractual term of the stock option and its weighted-average vesting term. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development, as there is limited stock price data available of the Company’s common stock since the IPO. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. The risk-free interest rates used are based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. treasury notes with maturities approximately equal to the expected term of the stock options. The Company has historically not declared or paid any dividends and does not currently expect to do so in the foreseeable future, and therefore has estimated the dividend yield to bezero.

The Company classifies stock-based compensation expense in its statements of operations and comprehensive loss in the same way the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified.

Common Stock Valuation

Due to the absence of an active market for the Company’s common stock prior to the IPO, the Company utilized methodologies, approaches and assumptions consistent with the American Institute of Certified Public Accountants’ Audit and Accounting Practice Guide: Valuation of Privately-Held Company Equity Securities Issued as Compensation to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the fair value of the common stock as of the grant date. The fair value of the common stock was determined based upon a variety of factors, including valuations the Company’s common stock performed by independent third-party valuation specialists; the anticipated capital structure that will directly impact the value of the currently outstanding securities; the Company’s results of operations and financial position; the status of the Company’s research and development efforts; the composition of, and changes to, the Company’s management team and board of directors; the lack of liquidity of the Company’s common stock as a private company; the Company’s stage of development and business strategy and the material risks related to the Company’s business and industry; external market conditions affecting the life sciences and biotechnology industry sectors; U.S. and global economic conditions; the likelihood of achieving a liquidity event for the holders of the Company’s common stock, such as an IPO or a sale of the Company, given prevailing market conditions; and the market value and volatility of comparable companies.

Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date.

Collaboration, License, and Development Support Revenue

The Company recognizes revenue from its collaboration, license and development support agreements, in a manner that depicts the transfer of control of a product or a service to a customer and reflects the amount of the consideration the Company is entitled to receive in exchange for such product or service. In doing so, the Company follows a five-step approach: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations; and (v) recognize revenue when (or as) the customer obtains control of the product or service. The Company considers the terms of a contract and all relevant facts and circumstances when applying the revenue recognition standard. The Company applies the revenue recognition standard, including the use of any practical expedients, consistently to contracts with similar characteristics and in similar circumstances.

A customer is a party that has entered into a contract with the Company, where the purpose of the contract is to obtain a product or a service that is an output of the Company’s ordinary activities in exchange for consideration. To be considered a contract: (i) the contract must be approved (in writing, orally, or in accordance with other customary business practices); (ii) each party’s rights regarding the product or the service to be transferred can be identified; (iii) the payment terms for the product or service to be transferred can be identified; (iv) the contract must have commercial substance (that is, the risk, timing or amount of future cash flows is expected to change as a result of the contract); and (v) it is probable that the Company will collect substantially all of the consideration to which it is entitled to receive in exchange for the transfer of the product or the service.

A performance obligation is defined as a promise to transfer a product or a service to a customer. The Company identifies each promise to transfer a product or a service (or a bundle of products or services, or a series of products and services that are substantially the same and have the same pattern of transfer) that is distinct. A product or a service is distinct if both (i) the customer can benefit from the product or the service either on its own or together with other resources that are readily available to the customer and (ii) the Company’s promise to transfer the product or the service to the customer is separately identifiable from other promises in the contract. Each distinct promise to transfer a product or a service is a unit of accounting for revenue recognition. If a promise to transfer a product or a service is not separately identifiable from other promises in the contract, such promises should be combined into a single performance obligation.

The transaction price is the amount of consideration the Company is entitled to receive in exchange for the transfer of control of a product or a service to a customer. To determine the transaction price, the Company considers the existence of any significant financing component, the effects of any variable elements, noncash considerations and consideration payable to the customer. If a significant financing component exists, the transaction price is adjusted for the time value of money. If an element of variability exists, the Company must estimate the consideration it expects to receive and uses that amount as the basis for recognizing revenue as the product or the service is transferred to the customer. There are two methods for determining the amount of variable consideration: (i) the expected value method, which is the sum of probability-weighted amounts in a range of possible consideration amounts; and (ii) the most likely amount method, which identifies the single most likely amount in a range of possible consideration amounts. The amount of variable consideration is included in the transaction price to the extent it is probable that a significant reversal of revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved.

If a contract has multiple performance obligations, the Company allocates the transaction price to each distinct performance obligation in an amount that reflects the consideration the Company is entitled to receive in exchange for satisfying each distinct performance obligation. For each distinct performance obligation, revenue is recognized when (or as) the Company transfers control of the product or the service applicable to such performance obligation.

Commitments and Contingencies

The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. The Company has not recorded any such liabilities as of December 31, 2025 or 2024.

Income Taxes

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

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

As of December 31, 2025 and 2024, the Company maintained full valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes may result in a change in the estimated annual effective tax rate.

The Company records uncertain tax positions on the basis of a two-step process whereby (i) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within the provision for income taxes in the statements of operations and comprehensive loss. Any accrued interest and penalties are included within the related tax liability in the balance sheets. As of December 31, 2025, the Company hadno accrued interest or penalties.

Comprehensive Loss

Comprehensive loss consists of net loss in excess of unrealized gains and losses on investments. The Company displays comprehensive loss and its components as part of the statements of operations and comprehensive loss.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common stock outstanding for the period. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and common stock equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company’s potentially dilutive securities include outstanding stock options and restricted stock units under the Company’s equity incentive plan and have been excluded from the computation of diluted net loss per share as they would be anti-dilutive to the net loss per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive for the years ended December 31, 2025 and 2024:

Recently Adopted Accounting Standards

In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity(ASU 2020-06). ASU 2020-06 was issued to reduce the complexity associated with accounting for certain financial instruments with characteristics of liabilities and equity. ASU 2020-06 reduces the number of accounting models for convertible debt instruments and redeemable convertible preferred stock and improves the disclosures for convertible instruments and related earnings per share guidance. ASU 2020-06 also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity and improves and amends the related earnings per share guidance. For public entities that qualify as a filer with the Securities and Exchange Commission, excluding entities eligible to be smaller reporting companies, ASU 2020-06 is effective for fiscal annual periods beginning after December 15, 2021, including interim periods within those fiscal years. For nonpublic entities, ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. ASU 2020-06 must be adopted as of the beginning of a Company’s annual fiscal year. The Company adopted this standard on January 1, 2024, and the adoption of the standard did not have amaterial impact on its financial statements.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280)—Improvements to Reportable Segment Disclosures (ASU 2023-07). The update requires entities to disclose their significant segment expense categories and amounts for each reportable segment. Significance is assessed using both quantitative and qualitative factors depending on the facts and circumstances. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and interim periods in fiscal years beginning after December 15, 2024. The Company adopted this standard for the fiscal year 2024 annual financial statements and interim financial statements thereafter and has applied this standard retrospectively for all prior periods presented in the financial statements (see Note 12).

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09). ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2025, with early adoption permitted. The Company adopted this standard for the fiscal year 2025 annual financial statements and has applied this standard retrospectively for all prior periods presented in the financial statements. The adoption impacted the disclosuresbut didnot have a material impact on the Company’s financial position, results of operations, or cash flows.

Recently Issued Accounting Standards Not Yet Adopted

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses(ASU 2024-03). The standard requires that public business entities disclose additional information about specific expense categories in the notes to financial statements for interim and annual reporting periods. The guidance is effective for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. The guidance is applied on a prospective basis, with a retrospective option, and early adoption is permitted. The Company is currently evaluating the impact of adoption of this standard on our financial statements and disclosures.

3. Fair Value Measurements

The following table presents information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis and indicates their respective levels within the fair value hierarchy (in thousands):

The carrying amounts of all cash and cash equivalents, accounts receivable, other receivables, prepaid and other current assets, accounts payable, and accrued expenses are considered to be representative of their respective fair values because of the short-term nature of those instruments.

Short-Term Investments

The Company’s assets with a fair value categorized as Level 2 within the fair value hierarchy consist of commercial paper, government and government agency bonds, and corporate debt obligations. These assets have been initially valued at the transaction price and subsequently valued at the end of each reporting period utilizing third-party pricing services. The pricing services utilize industry standard valuation models whereby all significant inputs, including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, bids, offers, or other market-related data, are observable.

Simple Agreements for Future Equity

The estimated fair value of the SAFEs is determined based on the aggregated, probability-weighted average of the outcomes of certain scenarios, including: (i) equity financing, with conversion of the SAFEs into a number of shares of convertible preferred stock at the lower of the post-money valuation cap price of $48.25 and the discount price (the lowest price of the standard convertible preferred stock sold in the equity financing multiplied by the specified discount rate of 85%);(ii) liquidity event (change of control, direct listing, or an initial public offering,)

with mandatory conversion to common stock at the lower of post-money valuation cap price of $48.25 and discount price (price of the common stock multiplied by the discount rate of 85%); and (iii) dissolution event, with SAFE holders automatically entitled to receive cash payments equal to the purchase amount, prior to and in preference to any distribution of any assets or surplus funds to the holders of convertible preferred and common stock. On May 29, 2024, the Company executed an amendment to the SAFEs (the SAFE Amendment). The SAFE Amendment amended the definition of liquidity event to exclude an initial public offering and amended the definition of the discount price under an initial public offering to the lower of (a) the price per share of common stock sold to the public by the underwriters in the initial public offering multiplied by the discount rate of 85% or (b) the post-money valuation cap price of $48.25. The combined value of the probability-weighted average of those outcomes is then discounted back to each reporting period in which the SAFEs are outstanding, in each case based on a risk-adjusted discount rate estimated based on the implied interest rate using the changes in observed interest rates of corporate debt that the Company believes is appropriate for those probability-adjusted cash flows.

Fair value measurements associated with SAFEs were determined based on significant inputs not observable in the market, which represent Level 3 measurements within the fair value hierarchy. Increases and decreases in the fair value of the SAFEs can result from updates to assumptions such as expected timing and probability of a qualified financing event, or changes in discount rates, among other assumptions. Based on management’s assessment of the valuation of the SAFEs, performed by the Company’s third-party valuation specialists, none of the changes in the fair value of those instruments were due to changes in the Company’s own credit risk for the reporting periods presented. Judgment is used in determining these assumptions as of the initial valuation date and at each subsequent reporting period. Changes or updates to assumptions could have a material impact on the reported fair value, and the change in fair value of SAFEs and the results of operations in any given period.

In connection with the closing of the IPO on July 22, 2024, the Company’s outstanding convertible SAFE shares automatically converted into 2,391,418 shares of common stock.

4. Cash, Cash Equivalents and Short-Term Investments

It is the Company’s policy to mitigate credit risk in its financial assets by maintaining a well-diversified portfolio that limits the amount of exposure as to maturity and investment type.

The following table summarizes the Company’s cash, cash equivalents and short-term investments (in thousands):

At December 31, 2025, the Company had 6 securities with contractual maturities of one year or less andone security with a contractual maturity greater than one year in an unrealized loss position, all of which have been in an unrealized loss position for less than 12 months. The Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost basis. As of December 31, 2025, no allowance for credit losses was recorded.

5. Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):

The Company recognized$2.5 million and $2.4 million in depreciation expense for the years ended December 31, 2025 and 2024, respectively.

6. Accrued Expenses

Accrued expenses consist of the following (in thousands):

7. Collaboration and License Agreements

The Company has entered into several agreements with GC Cell and related entities concerning its NK cell therapy platform and manufacturing of its core products, as described below.

In September 2019, the Company entered into an option and license agreement with GC Cell, formerly Green Cross Cell Corporation, as amended in June 2020 and February 2022 (the Core Agreement). Under the Core Agreement, GC Cell granted the Company an exclusive, royalty-bearing license, with the right to sublicense through multiple tiers, under certain intellectual property and technology owned or controlled by GC Cell relating to non-genetically modified and genetically modified NK cells, and culturing, engineering, manufacturing thereof, to research, develop, manufacture, and commercialize NK cell pharmaceutical products anywhere in the world except for Asia, Australia, and New Zealand (the Artiva Territory). GC Cell retained rights under the license to allow it and its affiliates to perform obligations under the Core Agreement and other agreements between the Company and them.

Under the Core Agreement, GC Cell agreed to conduct a discovery, research, preclinical development, and manufacturing program under a plan approved by a Joint Steering Committee (the JSC), to generate and identify product candidates for nomination as option candidates. GC Cell will bear all costs for its work under the R&D Plan (as defined in the Core Agreement), except that the Company will bear all costs for completing IND-enabling activities performed by GC Cell on behalf of the Company, other than certain efficacy studies.

For each product candidate determined by the JSC to be an option candidate, the Company has an exclusive option under the Core Agreement to obtain an exclusive, sublicensable license to research, develop, manufacture and commercialize such candidate in the Artiva Territory for any therapeutic, prophylactic or diagnostic uses in humans, on economic terms to be determined in good faith by the parties. GC Cell retains exclusive rights to the licensed technology in Asia, Australia, and New Zealand, though the Company has the right to request, and GC Cell has agreed to consider in good faith, inclusion of Australia, New Zealand, and/or specific countries in Asia in the Artiva Territory on a product-by-product basis. If the Company elects not to exercise the option with respect to a particular option candidate, GC Cell retains the right to continue development of such candidate. As of December 31, 2025, the Company has exercised its rights to license four option candidates, AB-101 (AlloNK), AB-201, AB-202, and AB-205, as described below.

The Company has control over and will bear the costs of the development, regulatory, manufacturing, and commercialization activities relating to the option candidates for which it has exercised its option, each a licensed product. Accordingly, the Company has certain diligence obligations and must use commercially reasonable efforts to develop and seek regulatory approval for each licensed product in at least one indication in the United States and the European Union, and following regulatory approval in a country, to commercialize such licensed product in at least one indication in such country. The Core Agreement provides that the Company has the right to engage GC Cell or its appropriate affiliate to provide research and manufacturing services for the licensed products being developed by the Company in the Artiva Territory under separately executed service agreements.

Under the Core Agreement, the Company is obligated to pay a low single-digit percentage royalty on net sales of any licensed products, the manufacture, use or sale of which is claimed by or uses certain core GC Cell intellectual property (Core IP). The royalty rate is subject to reduction under certain scenarios, and royalties are payable on a product-by-product and country-by-country basis, beginning with the first commercial sale of a licensed product and continuing until the later of: (i) expiration of the last-to-expire claim of the licensed patents and jointly owned patents in the country of sale; (ii) expiration of any regulatory exclusivity for a licensed product in that country; and (iii) the tenth anniversary of the first commercial sale of a licensed product in that country. The Company also has the exclusive option to extend its license to the Core IP to be worldwide with respect to products originated from the Company in exchange for a specified increase in the applicable royalty. GC Cell is also obligated to pay the Company a royalty at a rate equal to 50% of the royalty payable by the Company for such product in the Artiva Territory on net sales outside the Artiva Territory of any licensed product, the manufacture, use or sale of which is claimed by or uses any jointly owned intellectual property. As of December 31, 2025, the Company has not recognized any net sales royalties under the Core Agreement.

In November 2019, the Company entered into a license agreement with GC Cell for its AB-101 product candidate, as amended in February 2022 (the AB-101 Agreement). AB-101 is the first product for which the Company exercised its option under the Core Agreement. Under the AB-101 Agreement, GC Cell granted the Company an exclusive, royalty-bearing license in the Artiva Territory, with the right to sublicense through multiple tiers, under certain intellectual property and technology owned or controlled by GC Cell, to research, develop, manufacture, and commercialize AB-101.

Under the AB-101 Agreement, the Company is obligated to pay tiered royalties in the low-mid to high single-digit percentage range on annual net sales of any licensed AB-101 products. The royalty rate is subject to reduction under certain scenarios, and royalties are payable on a product-by-product and country-by-country basis, beginning with the first commercial sale of a licensed AB-101 product and continuing until the later of: (i) expiration of the last-to-expire claim of the licensed patents and jointly owned patents in the country of sale; (ii) expiration of any regulatory exclusivity for a licensed product in that country; and (iii) the tenth anniversary of the first commercial sale of a licensed product in that country. The Company is also obligated to make milestone payments to GC Cell of: (1) up to $22.0 million upon the first achievement of certain development milestones; and (2) up to $55.0 million upon the first achievement of certain sales milestones. GC Cell is also obligated to pay the Company a royalty at a rate equal to 50% of the royalty payable by the Company for such product in the Artiva Territory on net sales outside the Artiva Territory of any licensed AB-101 product, the manufacture, use or sale of which is claimed by or uses any jointly owned intellectual property. As of December 31, 2025, the Company hasnot recognized any net sales royalties or milestones under the AB-101 Agreement.

In October 2020, the Company entered into a license agreement with GC Cell for its AB-201 product candidate, as amended in February 2022 (the AB-201 Agreement). AB-201 is the second product for which the Company exercised its option under the Core Agreement. Under the AB-201 Agreement, GC Cell granted the Company an exclusive, royalty-bearing license in the Artiva Territory, with the right to sublicense through multiple tiers, under certain intellectual property and technology owned or controlled by GC Cell, to research, develop, manufacture, and commercialize AB-201.

Under the AB-201 Agreement, the Company is obligated to pay tiered royalties in the mid to high single-digit percentage range on annual net sales of any licensed AB-201 products. The royalty rate is subject to reduction under certain scenarios, and royalties are payable on a product-by-product and country-by-country basis, beginning with the first commercial sale of a licensed AB-201 product and continuing until the later of: (i) expiration of the last-to-expire claim of the licensed patents and jointly owned patents in the country of sale; (ii) expiration of any regulatory exclusivity for a licensed product in that country; and (iii) the tenth anniversary of the first commercial sale of a licensed product in that country. The Company is also obligated to make milestone payments to GC Cell of: (1) up to $25.0 million upon the first achievement of certain development milestones; and (2) up to $55.0 million upon the first achievement of certain sales milestones. GC Cell is also obligated to pay the Company a royalty at a rate equal to 50% of the royalty payable by the Company for such product in the Artiva Territory on net sales outside the Artiva Territory of any licensed AB-201 product, the manufacture, use or sale of which is claimed by or uses any jointly owned intellectual property.

In September 2023, the Company entered into an amendment to the AB-201 Agreement (the Amended AB-201 Agreement). This amendment granted back to GC Cell an exclusive, royalty and milestone bearing license to all information and patents controlled by the Company that relate specifically to the research, development, manufacture and use of AB-201, to be used outside of the Artiva Territory. Under the Amended AB-201 Agreement, the Company will receive tiered royalties in the low single-digit percentage range on annual GC Cell net sales of AB-201 outside of the Artiva Territory. The royalties are payable on a product-by-product and country-by-country basis, beginning with the first commercial sale of AB-201 outside of the Artiva Territory and continuing until the later of: (i) expiration of the last-to-expire claim of the licensed patents in the country of sale; (ii) expiration of any regulatory exclusivity for a licensed product in that country; and (iii) the tenth anniversary of the first commercial sale of a licensed product in that country. The Company will also receive milestone payments upon achievement of certain development milestones, totaling $1.8 million. In December 2023, GC Cell achieved the first regulatory milestone under the Amended AB-201 Agreement for first IND acceptance for AB-201 outside the Artiva Territory.

The Company recognized zero and $0.3 million of license and development support-related revenue during the years ended December 31, 2025 and 2024, respectively, in the statements of operations and comprehensive loss, related to development support activities under the Amended AB-201 Agreement. As of December 31, 2025 and December 31, 2024, there wereno accounts receivable related to the Amended AB-201 Agreement.

In December 2022, the Company entered into a license agreement with GC Cell for its AB-205 product candidate (the AB-205 Agreement). AB-205 is the fourth product for which the Company exercised its option under the Core Agreement. Under the AB-205 Agreement, GC Cell granted the Company an exclusive, royalty-bearing license in the Artiva Territory, with the right to sublicense through multiple tiers, under certain intellectual property and technology owned or controlled by GC Cell, to research, develop, manufacture, and commercialize AB-205.

Under the AB-205 Agreement, the Company is also obligated to pay tiered royalties in the mid to high single-digit percentage range on annual net sales of any licensed AB-205 products. The royalty rate is subject to reduction under certain scenarios, and royalties are payable on a product-by-product and country-by-country basis, beginning with the first commercial sale of a licensed AB-205 product and continuing until the later of: (i) expiration of the last-to-expire claim of the licensed patents and jointly owned patents in the country of sale; (ii) expiration of any regulatory exclusivity for a licensed product in that country; and (iii) the tenth anniversary of the first commercial sale of a licensed product in that country. Upon election by the Company to proceed with clinical development of AB-205 (prior to which the Company may not make, use or sell AB-205 for clinical development purposes), the Company is obligated to pay a one-time payment of $2.5 million to GC Cell. Thereafter, the Company is also obligated to make milestone payments to GC Cell of: (i) up to $29.5 million upon the first achievement of certain development milestones, excluding any payments for the Development Cost Share as defined in the AB-205 Agreement; and (ii) up to $28.0 million upon the first achievement of certain sales milestones. As of December 31, 2025, the Company hasnot recognized any net sales royalties or milestones under the AB-205 Agreement.

In connection with the AB-205 License Agreement, the Company recognized zero and $0.1 million of expense reimbursements for development costs invoiced to GC Cell for the years ended December 31, 2025 and 2024, respectively. The Companydidnot receive any payments from GC Cell during the year ended December 31, 2025.

During the year ended December 31, 2024, the Company received payments from GC Cell totaling $0.7 million. As of December 31, 2025 and December 31, 2024, the Company had no receivables from GC Cell recorded in the balance sheets in relation to the AB-205 Agreement.

As contemplated by the Core Agreement, in August 2020 the Company entered into the GC Cell Research Services Agreement, as amended in February 2022, under which GC Cell agreed to provide research services in support of the research and development of one or more of the products the Company has licensed from GC Cell.

The agreement provides that the parties will agree to specific projects as work orders under the GC Cell Research Services Agreement. Each work order shall set forth, upon terms mutually agreeable to GC Cell and the Company, the specific services to be performed by GC Cell, the timeline and schedule for the performance of the services, and the compensation to be paid by the Company to GC Cell for the provision of such services, as well as any other relevant terms and conditions (see Note 9).

In March 2020, the Company entered into a Master Agreement for Manufacturing Services (the Manufacturing Agreement) with GC Cell, under which GC Cell agreed to manufacture specified products under individual work orders for use in the Company’s Phase 1 and Phase 2 clinical trials. Each work order will contain an estimated budget of service fees and out-of-pocket costs to be incurred in the performance of services under the agreement and the work order, as well as additional terms and conditions relating to the estimated budget. The Company will own all results and data generated by GC Cell under the Manufacturing Agreement (see Note 9).

8. Convertible Preferred Stock, Stockholders’ Equity, and Stock-Based Compensation

Stockholders’ Equity

Under the Amended and Restated Certificate of Incorporation dated July 22, 2024, the Company had a total of 710,000,000 shares of capital stock authorized for issuance, consisting of 700,000,000 shares of common stock, par value of $0.0001 per share, and 10,000,000 shares of preferred stock, par value of $0.0001 per share. Additionally, the Company has authorized 84,556 shares reserved under the terms specified as part of the Company’s Pledge 1% Movement commitment, in support of its corporate social responsibility and philanthropic pursuits.

Convertible Preferred Stock

In 2020 and 2021, the Company issued 2,077,165 shares and 1,595,983 shares, respectively, of Series A convertible preferred stock at a price of $21.93 per share, resulting in aggregate gross proceeds of $70.0 million and total issuance costs of $0.4 million. The Company converted a promissory note with a fair value of $10.6 million as part of the first closing and reclassified a convertible preferred stock purchase right liability with a fair value of $23.7 million into equity as part of the second closing.

In 2021, the Company issued 2,487,237 shares of Series B convertible preferred stock at a price of $48.25 per share resulting in aggregate gross proceeds of $120.0 million and incurred $0.4 million of total issuance costs.

As of December 31, 2023, the Company’s Series A and Series B convertible preferred stock was classified as temporary equity in the balance sheets given that the holders of the convertible preferred stock could cause certain events to occur that are outside of the Company’s control whereby the Company could be obligated to redeem the convertible preferred stock. The carrying value of the convertible preferred stock was not adjusted to the redemption value until the contingent redemption events are considered to be probable of occurring.

The Company’s convertible preferred stock had the following rights, preferences and privileges:

Dividends

The Company shall not declare, pay or set aside any dividends on shares of any class of capital stock of the Company unless the holders of the Series A or Series B convertible preferred stock shall first receive, or simultaneously receive, a dividend on each outstanding share of the Series A convertible preferred stock equal to an amount as defined in the Company’s Amended and Restated Certificate of Incorporation. No such dividends have been declared or paid through December 31, 2025.

Preferences on Liquidation

The holders of the Series A convertible preferred stock are entitled to receive liquidation preferences, in the event of a change in control, at an amount per share equal to the greater of (i) the Series A original issuance price of $21.93, plus any dividends declared but unpaid or (ii) such amount per share as would have been payable had all shares of Series A convertible preferred stock been converted into common stock. The holders of the Series B convertible preferred stock are entitled to receive liquidation preferences, in the event of a change in control, at an amount per share equal to the greater of (1) the Series B original issuance price of $48.25, plus any dividends declared but unpaid or (2) such amount per share as would have been payable had all shares of Series B convertible preferred stock been converted into common stock. Liquidation payments to the holders of the Series A and Series B convertible preferred stock have priority and are made in preference to any payments to the holders of common stock.

After full payment of the liquidation preference to the holders of the Series A and Series B convertible preferred stock, the remaining assets, if any, will be distributed ratably to the holders of the common stock.

Conversion Rights

The shares of Series A and Series B convertible preferred stock are convertible into an equal number of shares of common stock, at the option of the holder, subject to certain anti-dilution adjustments. The conversion rate for the convertible preferred stock is determined by dividing the original issue price by the conversion price. The conversion price is initially the original issue price, but is subject to adjustment for dividends, stock splits, and other distributions. The conversion rate at December 31, 2023, for the Series A and Series B convertible preferred stock was 1:1.

Each share of Series A convertible preferred stock will be automatically converted into common stock at the then effective conversion rate (subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to the common stock) upon: (i) the closing of the sale of common stock to the public in a firm-commitment underwritten public offering pursuant to an effective registration statement under the Securities Act of 1933, as amended, resulting in at least $75.0 million of gross proceeds to the Company; or (ii) the date and time, or the occurrence of an event, specified by vote or written consent of the holders of 60% of the outstanding shares of Series A convertible preferred stock. Each share of Series B convertible preferred stock will be automatically converted into common stock at the then effective conversion rate (subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to the common stock) upon: (1) the closing of the sale of common stock to the public in a firm-commitment underwritten public offering pursuant to an effective registration statement Securities Act of 1933, as amended, resulting in at least $75.0 million of gross proceeds to the Company; or (2) the date and time, or the occurrence of an event, specified by vote or written consent of the holders of 60% of the outstanding shares of Series B convertible preferred stock.

Redemption Rights

The holders of Series A and Series B convertible preferred stock do not have any redemption rights, except upon certain liquidation events that are outside of the Company’s control.

Voting

The holder of each share of Series A and Series B convertible preferred stock generally vote together with the shares of common stock as a single class, but also have class vote approval rights as provided by the Company’s certificate of incorporation or as required by applicable law.

Immediately upon completion of the IPO,6,160,385 outstanding shares of convertible preferred stock converted into 6,160,385 shares of common stock. There wereno Series A or Series B convertible preferred shares outstanding as December 31, 2025 and 2024.

At-the-Market Offering Program

In August 2025, the Company entered into a sales agreement (the Sales Agreement) with Leerink Partners LLC (the Agent), under which the Company may, from time to time, sell shares of the Company’s common stock having an aggregate offering price of up to $11,950,000 in “at the market” offerings (the ATM Offering Program) through the Agent. Sales of the shares of common stock will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Agent. The Agent will receive a commission from the Company of up to 3.0% of the gross proceeds of any shares of common stock sold under the Sales Agreement. No shares of common stock were sold under the ATM Offering Program during the year ended December 31, 2025.

Common Stock

The holders of the common stock are entitled to one vote for each share of common stock held at all meetings of stockholders.

Common stock reserved for future issuance consisted of the following:

Stock Options

In June 2020, the Company adopted the 2020 Equity Incentive Plan (the 2020 Plan). The 2020 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, and other stock awards.

The 2020 Plan was amended in December 2020, January 2021, July 2021, August 2022, and in April 2024. In April 2024, the 2020 Plan was amended to increase the total number of shares reserved under the 2020 Plan to 2,083,797.

In July 2024, in connection with the closing of the IPO, the Company’s board of directors adopted the 2024 Equity Incentive Plan (the 2024 Plan), a successor to and continuation of the 2020 Plan. Upon the effectiveness of the 2024 Plan,4,572,025 shares of common stock were authorized for issuance which consists of (1)2,630,000 new shares of common stock, (2)115,436 shares available for issuance under the 2020 Plan, and (3) up to 1,826,589 sharesof common stock subject to outstanding stock awards granted under the 2020 Plan that, on or after the 2024 Plan became effective, expire or otherwise terminate prior to exercise or settlement; are not issued because the stock award is settled in cash; are forfeited or repurchased because of the failure to vest; or are reacquired or withheld to satisfy a tax withholding obligation or the purchase or exercise price, if any, as such shares become available from timeto time. Furthermore, as of the effectiveness of the 2024 Plan, no further grants can be made under the 2020 Plan, and the 2020 Plan will automatically terminate on June 23, 2030. The 2024 Plan provides that the number of shares reserved and available for issuance under the 2024 Plan will automatically increase each January 1, beginning on January 1, 2025, by 5.0% of the outstanding number of shares of common stock on the immediately preceding December 31st. On January 1, 2025,1,214,580 shares were added to the 2024 Plan reserve. On June 24, 2025, the Company’s stockholders approved an amendment to the 2024 Plan to increase the 2024 Plan reserve by an additional 1,214,580 shares.

Options granted under the 2024 Plan are exercisable at various dates as determined upon grant and will expire no more than 10 years from their date of grant. The exercise price of each option shall be determined by the board of directors based on the estimated fair value of the Company’s stock on the date of the option grant. The exercise price shall not be less than 100% of the fair market value of the Company’s common stock at the time the option is granted. Most option grants generally vest 25% on the first anniversary of the original vesting commencement date, with the balance vesting monthly over the remaining three years and early exercise is permitted. The vesting period generally occurs over four years unless there is a specific performance vesting trigger at which time those shares will vest when the performance trigger is probable to occur.

In December 2025, the Company entered into Option for RSU Exchange Agreements (the Option for RSU Exchange Agreements or the Exchange Program) with a limited number of employees. These agreements provided a one-time opportunity for eligible participants to surrender outstanding stock options with exercise prices greater than the current fair market value of the Company’s common stock in exchange for restricted stock units (RSUs) granted under the Company’s 2024 Equity Incentive Plan. The RSU grants became effective on December 12, 2025 and will vest on a quarterly basis between August 15, 2026 and August 15, 2029 with various vesting terms in accordance with the employee’s Option for RSU Exchange Agreements.

As a result of the Exchange Program,1,363,777 vested and unvested options were cancelled on December 12, 2025 and 1,363,777 new RSUs were granted on the same day. The total incremental fair value to be recognized as a result of the Program is $2.7 million and will be recognized over the vesting period of the underlying awards. The expense is included within the respective line item on thestatement of operations and comprehensive loss corresponding to the activity of the related employee. During the year ended December 31, 2025, the Company recorded $0.1 million of stock-based compensation expense in relation to the Exchange Program.

A summary of the Company’s stock option activity under the 2020 Plan and 2024 Plan is as follows:

The Company recorded stock-based compensation expense related to employee and non-employee options in the amounts of$4.1 million and $6.2 million for the years ended December 31, 2025 and 2024, respectively. The weighted-average grant date fair value of options granted for the years ended December 31, 2025 and 2024, was$2.57 and $8.79 per share, respectively. The total intrinsic value of options exercised during the years ended December 31, 2025 and 2024 waszero. Upon the exercise of stock options, the Company will issue new shares of its common stock. As of December 31, 2025, the unrecognized compensation cost related to outstanding employee and non-employee options was$1.1 million and is expected to be recognized as expense over a weighted-average period of 2.0 years.

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee and non-employee stock option grants issued for the years ended December 31, 2025 and 2024, were as follows:

Employee Stock Purchase Plan

In connection with the closing of the IPO, the Company’s board of directors adopted the 2024 Employee Stock Purchase Plan (the ESPP). The ESPP provides for two-year offering periods consisting of four 6-month purchase periods, and 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 on the first trading day of the offering period or on the last trading day of the purchase period. A new offering is initiated each January 16 and July 16. In the event the fair market value of the Company’s common stock on the first day of any new offering is less than or equal to the fair market value of an ongoing offering, the ongoing offering shall terminate immediately following the purchase of shares of common stock on the purchase date immediately preceding the new offering and participants in the terminated ongoing offering will be automatically enrolled in the new offering.

An aggregate of 212,000 shares were initially reserved and available for issuance under the ESPP. The ESPP provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2025, by the lesser of 1.0% of the outstanding number of shares of common stock on the immediately preceding December 31, and 424,000 shares of common stock. On January 1, 2025,242,916 shares were added to the ESPP reserve.76,916 shares were issued under the ESPP during the year ended December 31, 2025. No shares were issued under the ESPP during the year ended December 31, 2024.

The ESPP is considered a compensatory plan. The Company recorded related stock-based compensation in the amounts of$0.4 million and $0.2 million for the years ended December 31, 2025 and 2024, respectively. The assumptions used to estimate the fair value of ESPP awards using the Black-Scholes option valuation model were as follows:

Restricted Stock Unit Awards

RSUs granted under the 2020 and 2024 Plan are subject to time-based vesting and convert to shares of common stock in accordance with the vesting schedule. RSUs are valued at the estimated fair value of the Company’s stock on the date of grant and are amortized over the requisite service period. The total number of RSUs granted represents the maximum number of RSUs eligible to vest based upon the service conditions set forth in the grant agreements. Employees forfeit unvested RSUs upon termination of employment with a corresponding reversal of expense.

A summary of the Company’s RSU activity under the 2020 Plan and 2024 Plan is as follows:

The Company recorded stock-based compensation expense related to RSUs in the amounts of$2.3 million and $0.5 million for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, the unrecognized compensation cost related to outstanding RSUs was$13.4 million and is expected to be recognized as expense over a weighted-average period of 2.7 years. The total fair value of RSUs vested during the year ended December 31, 2025 was$0.8 million.

The following table summarizes stock-based compensation expense by financial statement line item in the Company’s statements of operations and comprehensive loss (in thousands):

9. Related Party Transactions

Relationship with GC Cell and GC Corp

GC Cell and GC Corp, subsidiaries of Green Cross Corp, are stockholders of the Company and are represented on the Company’s board of directors.

The Company entered into license agreements in November 2019, October 2020, March 2021, and December 2022 (collectively, the License Agreements) with GC Cell (see Note 7). In August 2020, the Company entered into a Research and Service Agreement with GC Cell in which GC Cell is to provide mutually agreed research services in support of the research and development of one or more of the Selected Products that the Company has licensed from GC Cell under the License Agreements. The Company didnot incur any research and development expense in connection with the agreements for the years ended December 31, 2025 and 2024. As of December 31, 2025 and December 31, 2024, the Company hadno accounts payable and accrued expenses in connection with the GC Cell License Agreements and Research Service Agreement.

In September 2023, the Company and GC Cell amended the AB-201 Agreement (see Note 7). The Company recognized zero and $0.3 million of license and development support-related revenue for the years ended December 31, 2025 and 2024, respectively, on its statements of operations and comprehensive loss, related to development support activities under the Amended AB-201 Agreement. As of December 31, 2025 and December 31, 2024, total accounts receivable related to the Amended AB-201 Agreement waszero.

Under the AB-205 Agreement, GC Cell agreed to reimburse the Company for direct costs incurred on behalf of GC Cell in accordance with the Development Plan under the AB-205 Agreement, provided that such reimbursed costs are deemed to form part of the direct costs incurred and paid by GC Cell (see Note 7). Total reimbursements for development costs invoiced to GC Cell in connection with the AB-205 Agreement were zero and $0.1 million for the years ended December 31, 2025 and 2024, respectively. The Company didnot receive any payments from GC Cell during the year ended December 31, 2025. During the year ended December 31, 2024, the Company received payments from GC Cell totaling $0.7 million. As of December 31, 2025 and December 31, 2024, the Company hadno receivables from GC Cell recorded in the balance sheets.

In March 2020, the Company entered into the Manufacturing Agreement with GC Cell, where GC Cell is to perform manufacturing services with respect to any biological or chemical product manufactured or to be manufactured for use in Phase 1 or Phase 2 clinical trials. The Company amended the Manufacturing Agreement in June 2020 to include the Company’s right to terminate the agreement at will. For the years ended December 31, 2025 and 2024, the Company incurred approximately$55 thousand and $2.9 million, respectively, in research and development expenses in connection with the agreement. As of December 31, 2025 and 2024, the Company hadzero and $1.0 million, respectively, of accounts payable and accrued expenses in connection with the Manufacturing Agreement recorded in the balance sheets.

Relationship with RA Capital

RA Capital Healthcare Fund, L.P., RA Capital Nexus Fund, L.P. and Blackwell Partners LLC—Series A (the RA Capital Funds) are stockholders of the Company and a member of the Company’s board of directors is affiliated with the RA Capital Funds.

In June 2024, the Company entered into a services agreement (the “Blackbird Services Agreement”) with Blackbird Clinical, Inc. (Blackbird), an entity controlled by RA Capital Management, L.P. RA Capital Management, L.P. is the investment manager for the RA Capital Funds. Under the terms of the Blackbird Services Agreement, Blackbird provides consulting services in connection with the Company’s clinical trials, including study strategy, clinical operations and patient operations. The agreement commenced on June 1, 2024 and was in effect until June 1, 2025. The Company incurred zero and $0.3 million of research and development expenses in connection with the consulting services from Blackbird for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, and December 31, 2024, the Company hadzero and $9 thousand in accounts payable and accrued expenses, respectively, in connection with the Blackbird Services Agreement recorded in the balance sheets.

In November 2024, the Company entered into a services agreement (the “Carnot Services Agreement”) with Carnot Pharma, LLC (Carnot), an entity controlled by RA Capital Management, L.P. RA Capital Management, L.P. is the investment manager for the RA Capital Funds. Under the terms of the Carnot Services Agreement, Carnot provides consulting services in connection with the Company’s clinical trials, including clinical operations and patient advocacy in support of the Company’s AlloNK autoimmune programs. The agreement commenced on November 1, 2024 and was in effect until December 31, 2025. The Company incurred $31 thousand and $15 thousand of research and development expenses in connection with the consulting services from Carnot for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, and December 31, 2024, the Company hadzero and $15 thousand in accounts payable and accrued expenses, respectively, in connection with the Carnot Services Agreement recorded in the balance sheets.

10. Commitments and Contingencies

Operating Leases

The Company has multiple facility leases in San Diego, California, for office and laboratory space, including a cGMP manufacturing center, under non-cancellable operating leases with various expiration dates through 2029.

The Company leased certain office space in San Diego, California, under a non-cancelable operating lease, with a term through December 2025 (the Executive Drive Lease). The lease agreement for 13,405 square feet commenced on December 23, 2019, with asix-year initial term and included aggregate monthly payments to the lessor of $2.8 million. The Executive Drive Lease also provided for rent abatements and scheduled increases in base rent. In connection with the lease, the Company made a one-time cash security deposit in the amount of $0.4 million, of which $0.2 million was refunded in October 2021, and the remaining $0.2 million is refundable at the end of the lease term and is included inprepaid expenses and other current assets in the Company’s balance sheets. The Executive Drive Lease included a renewal option, which included an option to renew for five additional years. The Company did not exercise the option and, as such, the Executive Drive Lease ended in December 2025.

In June 2021, the Company entered into a lease agreement for 51,621 square feet of office and laboratory space, and a cGMP manufacturing center in San Diego, California (the Morehouse Lease), which represented a portion of a new facility that was under construction. The construction and design of the asset was the primary responsibility of the lessor. The Company was involved in certain aspects of construction and design for certain interior features and leasehold improvements that will be beneficial to the Company to better suit its business needs and intended purpose of the space. The Morehouse Lease is accounted for as an operating lease and commenced in the second quarter of 2022 (office and laboratory space) and in the third quarter 2022 (cGMP manufacturing center). The Morehouse Lease has an initial term of 88 months and includes aggregate monthly payments to the lessor of approximately $23.2 million with a rent escalation clause, and a tenant improvement allowance of approximately $12.3 million. The lease agreement required the Company to provide an unconditional and irrevocable letter of credit in the amount of $0.2 million, which is recorded as restricted cash on the Company’s balance sheets as of December 31, 2025 and 2024.

In August 2022, the Company entered into a lease agreement to use designated laboratory and vivarium space in San Diego, California (the Explora Lease). The Explora Lease is accounted for as an operating lease and commenced in August 2022. The Explora Lease had an initial term of 36 months with automatic one-year renewals for up to three additional yearsand includes aggregate monthly payments to the lessor of approximately $0.8 million with a rent escalation clause. The Company extended the lease through August 2026.

In March 2025, the Company entered into a lease agreement with Eastgate Bend Two for a warehouse and storage facility space in San Diego, California (the Eastgate Lease). The Eastgate Lease is accounted for as an operating lease and commenced on March 1, 2025. The Eastgate Lease has an initial term of 54 months and includes aggregate monthly payments to the lessor of approximately $0.5 million for the 54 month term with scheduled increases in base rent.

The following table presents operating rent expense and related short-term lease costs (in thousands):

Future minimum annual obligations under the Company’s operating leases with terms in excess of one year are as follows (in thousands):

As the Company’s leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on average discount rate, which were as follows:

On July 22, 2022, the Company entered into a sublease (the Sublease Agreement) with Origis Operating Services, LLC, (the Sublessee), whereby the Company agreed to sublease to Sublessee all of the 13,405 rentable square feet of office space in San Diego, California previously leased by the Company under the Executive Drive Lease. The sublease commenced on August 1, 2022, and had a term through December 31, 2025. The aggregate base rent was approximately $2.6 million commencing August 1, 2022. The Company recorded sublease income as a reduction of general and administrative expense.

The Company recognized sublease income of $0.8 million for each of the years ended December 31, 2025 and 2024.

11. Income Taxes

The Company reported pre-tax book losses in the United States of $83.9 million and $65.4 million, for the years ended December 31, 2025 and 2024, respectively.

A reconciliation of the U.S. federal statutory income tax rate to the effective tax rate is as follows (in thousands):

(1) 50% or more of our state tax provision relates to the California taxing jurisdiction.

Due to losses, the Company didnot pay any federal and state income taxes in 2025 or 2024.

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

The Company increased its valuation allowance by$24.5 million for the year ended December 31, 2025 in order to maintain a full valuation allowance against its deferred tax assets. The Company recorded a full valuation allowance against its net deferred tax assets as of December 31, 2025 due to the uncertainty surrounding the realization of such assets. The Company has determined it more likely than not that the deferred tax assets are not realizable due to the Company's historical loss position. The Company intends to maintain a valuation allowance until sufficient positive evidence exists to support a reversal of the allowance.

The Company has net operating loss (NOL) carryforwards for federal and state income tax purposes of $195.0 million and$217.7 million, respectively, as of December 31, 2025. All of the federal net operating loss carryforwardsare not subject to expiration but are limited to 80% of the taxable income in the year the carryforward is used. The state net operating loss carryforwards, if not utilized, will start to expire in 2039.

As of December 31, 2025, the Company has federal and state research and development credit carryforwards of$10.6 million and $6.8 million, respectively. The federal credits will start to expire in 2041 and the state credits are available indefinitely.

Pursuant to Sections 382 and 383 of the Code, and corresponding provisions of state law, annual use of the Company’s federal and state NOLs and research and development credit carryforwards may be limited in the event of a cumulative ownership change of more than 50 percentage points (by value) within a rolling three-year period. The Company has not completed an ownership change analysis pursuant to Section 382. If ownership changes have occurred or occurs in the future, the amount of remaining tax attribute carryforwards available to offset taxable income and income tax expense in future years may be restricted or eliminated. If eliminated, the related asset would be removed from deferred tax assets with a corresponding reduction in the valuation allowance.

The Company files income tax returns in the United States federal jurisdiction and California. The Company is not currently under examination by any federal, state or local tax authority and all tax years from inception remain open to United States federal and state examination to the extent of the utilization of net operating loss and credit carryovers.

As of December 31, 2025, the Company had unrecognized tax benefits of$6.2 million related primarily to the federal and state research and development credits as a result of no formal research credit study performed.

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

Due to the full valuation allowance, future recognition of previously unrecognized tax benefits will not impact the Company’s effective tax rate. The Company recognizes interest expense and penalties related to the above unrecognized tax benefits within income tax expense (benefit). Management determined thatno accrual for interest and penalties was required as of December 31, 2025.

On July 4, 2025, the One Big Beautiful Bill Act (the OBBBA) was enacted in the United States. The OBBBA includes corporate provisions that make 100% bonus depreciation permanent, allow for the expensing of domestic research costs, and modifies the business interest expense limitation calculation. These changes were incorporated into our income tax provision for the tax year ended December 31, 2025, resulting in no impact to our fiscal year 2025 effective tax rate and net deferred tax assets as we maintain a full valuation allowance.

12. Segment Information

The Company operates and manages its business asone reportable and operating segment, which is the business of developing therapies for autoimmune diseases and cancers. The Company’s chief operating decision maker (CODM) is thechief executive officer, whoassesses performance of the segment based on net loss, which includes evaluating the progress of ongoing clinical trials. The measure of segment assets is reported on the balance sheet as total assets. All long-lived assets are maintained in the United States. The following table contains information on segment profit or loss, including significant segment expenses (in thousands):

(a)

Other programs primarily include costs associated with AB-201.

(b)

Other primarily includes consultant, depreciation, rent, common area maintenance, lab supplies, legal, and insurance expenses.