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 debilitating autoimmune diseases.

From its inception to September 30, 2026, 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.

On October 27, 2026, the Company announced the wind-down of its AlloNK development program, which includes a plan to implement a reduction of the Company’s workforce, as the Company conducts a process to explore strategic alternatives to maximize stockholder value. The Company continues to conduct clinical, regulatory, scientific and intellectual property activities following the announcement, as described in Note 12, Subsequent Events. Refer to Note 12, Subsequent Events, to these interim condensed financial statements for further discussion of this non-recognized subsequent event.

Public Equity Offering

In May 2026, the Company completed a public offering of common stock (May 2026 Offering), pursuant to which it issued and sold 23,871,526 shares of common stock at a price of $11.52 per share under a shelf registration statement. In addition, the Company issued pre-funded warrants, in lieu of common stock to certain investors, to purchase 2,170,138 shares of the Company’s common stock (Pre-Funded Warrants). The purchase price of the Pre-Funded Warrants was $11.5199 per Pre-Funded Warrant, which equals the per share public offering price for the shares of common stock less the $0.0001 exercise price for each such Pre-Funded Warrant (see Note 8). Gross proceeds from the public offering and the issuance of the Pre-Funded Warrants were $300.0 million, and after giving effect to$17.3 million in costs related to the public offering and the issuance of Pre-Funded Warrants, net proceeds were$282.7 million.

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 as it explores strategic alternatives. 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 $407.9 million as of September 30, 2026. During the nine months ended September 30, 2026, the Company used $69.8 million of cash for operating activities. As of September 30, 2026, the Company has $319.1 million in cash, cash equivalents and short-term investments. The Company has also announced that it is winding down the development of its AlloNK program and exploring strategic alternatives. From inception through September 30, 2026, the Company has raised aggregate gross proceeds of$742.4 million to fund operations, comprised primarily of proceeds received from the Initial Public Offering (the IPO), including proceeds from the underwriters’ partial exercise of their overallotment option, proceeds received from the May 2026 Offering, issuances of convertible promissory notes, simple agreements for future equity (SAFEs), private placements of convertible preferred stock, and funds received from collaboration arrangements.

The Company believes its existing cash, cash equivalents and short-term investments will be sufficient to fund planned operations for at least one year from the issuance of these financial statements. The Company’s future funding requirements will depend on the costs of winding down its AlloNK development program, satisfying its remaining obligations and the outcome of its strategic review. If the Company resumes development of its current or new product candidates, it will need to secure substantial additional funding to conduct research and development and regulatory activities, conduct any substantial additional development requested by the FDA, and commercialize product candidates. If the Company is unable to obtain additional funding when needed, it may be unable to pursue such activities or satisfy its remaining obligations, which could adversely affect its business prospects. The Company is exploring strategic alternatives, which may include, among other alternatives, a potential sale or licensing of its assets, including, but not limited to AlloNK or its other current product candidates, an in-license arrangement, sale of the company, business combination, merger or other strategic transaction. There can be no assurance that the Company will be able to consummate any such strategic alternative on acceptable terms or at all. There is also no assurance that the Company will be successful in obtaining additional funding, if needed, on terms acceptable to the Company, if at all.

Basis of Presentation

The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) and pursuant to rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. These unaudited condensed financial statements include only normal and recurring adjustments that the Company believes are necessary to fairly state the Company’s financial position and the results of its operations and cash flows. The results for the three and nine months ended September 30, 2026 and 2025 are not necessarily indicative of the results expected for the full fiscal year or any subsequent interim period. The unaudited condensed balance sheet as of September 30, 2026, has been derived from the financial statements as of that date but does not include all disclosures required by GAAP for complete financial statements. As all of the disclosures required by GAAP for complete financial statements are not included herein, these condensed financial statements and the notes accompanying herein should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2025, included in the Company's Annual Report on Form 10-K filed with the SEC on March 10, 2026 (the Annual Report). 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

The Company’s significant accounting policies are disclosed in the audited financial statements as of and for the year ended December 31, 2025, included in the Annual Report. Since the date of those financial statements, there have been no changes to its significant accounting policies, except where noted below.

Pre-Funded Warrants

Pre-funded warrants are accounted for as either derivative liabilities or as equity instruments depending on the specific terms of the agreement. The Pre-Funded Warrants are equity-classified instruments that were recorded in additional paid-in capital at issuance and are not subject to remeasurement. The Company periodically evaluates changes in facts and circumstances that could impact the classification of warrants.

Use of Estimates

The preparation of condensed 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 condensed financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the condensed financial statements include: the accrual of research and development expenses, stock-based compensation, 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.

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 condensed 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 condensed 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 condensed statements of operations and comprehensive loss.

As of September 30, 2026, and December 31, 2025, accrued interest receivables on investments were$1.7 million and$0.7 million, respectively, and are included inprepaid expenses and other current assets in the condensed 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 thethree and nine months ended September 30, 2026 and 2025.

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 September 30, 2026, and December 31, 2025, was$0.5 million, consisting of collateral for letters of credit related to the Company’s lease agreements and funds to support the Company's cash secured credit card program, and is included in non-current assets in the condensed balance sheets.

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. The Pre-Funded Warrants associated with the May 2026 public equity offering (see Note 8) are considered outstanding shares in the basic earnings per share calculation given their nominal exercise price. 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:

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 the Company's 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.

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 September 30, 2026, the Company had 34 securities with contractual maturities of one year or less and 43 securities 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 September 30, 2026, 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 $0.7 million and $2.1 million in depreciation expense for the three and nine months ended September 30, 2026, respectively, and $0.6 million and $1.9 million in depreciation expense for the three and nine months ended September 30, 2025, 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.

Option and License Agreement with GC Cell

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 September 30, 2026, 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 September 30, 2026, the Company has not recognized any net sales royalties under the Core Agreement.

AB-101 Selected Product License 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 September 30, 2026, the Company hasnot recognized any net sales royalties or milestones under the AB-101 Agreement.

AB-201 Selected Product License 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. In May 2026, the first patient was dosed in an investigator-initiated Phase 1 dose-escalation study of AB-201 in patients with advanced HER2-positive gastric or gastroesophageal junction cancer in South Korea.

The Company didnot recognize any license and development support-related revenue during the three and nine months ended September 30, 2026 and 2025. As of September 30, 2026, and December 31, 2025, there wereno accounts receivable related to the Amended AB-201 Agreement.

AB-205 Selected Product License 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 September 30, 2026, the Company hasnot recognized any net sales royalties or milestones under the AB-205 Agreement.

In connection with the AB-205 Agreement, the Companydidnot recognize any expense reimbursements for development costs invoiced to GC Cell for the three and nine months ended September 30, 2026 and 2025. The Company didnot receive any payments from GC Cell during thethree and nine months ended September 30, 2026 and 2025. As of September 30, 2026 and December 31, 2025, the Companyhadno receivables from GC Cell recorded in the condensed balance sheets in relation to the AB-205 Agreement.

Research Services Agreement with GC Cell

As contemplated by the Core Agreement, in August 2020 the Company entered into the GC Cell Research Services Agreement (the 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).

Master Manufacturing Agreement with GC Cell

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. 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.

Pre-Funded Warrants

Inconjunction with the May 2026 Offering, the Company issued Pre-Funded Warrants, in lieu of common stock to certain investors, to purchase 2,170,138 shares of the Company’s common stock. The purchase price for the Pre-Funded Warrants was $11.5199 per Pre-Funded Warrant, which equals the per share public offering price for the shares of common stock less the $0.0001 exercise price for each such Pre-Funded Warrant. Given that the Pre-Funded Warrants are indexed to the Company’s own shares of common stock (and otherwise meet the requirements to be classified in equity), the Company recorded the consideration received from the issuance of the warrants as additional paid-in capital on the Company’s unaudited condensed balance sheets.

The Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of Pre-Funded Warrants may not exercise the Pre-Funded Warrant if the holder would beneficially own more than 4.99% (or 9.99% together with its affiliates and other attribution parties), of the number of shares of the Company’s common stock outstanding immediately after giving effect to such exercise. A holder of Pre-Funded Warrants may increase or decrease this percentage not in excess of 19.99% by providing at least 61 days’ prior notice to the Company.

As of September 30, 2026, there were 2,170,138 Pre-Funded Warrants outstanding.

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. In August 2026, the Company entered into an amended and restated sales agreement with the Agent, increasing the aggregate offering price allowable under the Sales Agreement to $100,000,000. 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 three and nine months ended September 30, 2026.

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 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 shares of 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 time to 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. On January 1, 2026,1,229,777 shares were added to the 2024 Plan reserve. On September 8, 2026, the Company's stockholders approved an amendment to the 2024 Plan to increase the 2024 Plan reserve by an additional 5,097,095 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 exerciseis 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's board of directors adopted and approved the Company’s 2025 Inducement Plan to reserve 600,000 shares of our common stock to be used for grants of equity-based awards to individuals that were not previously employees or directors of the Company (or who are returning to employment following a bona fide period of non-employment), as an inducement material to the individual’s entry into employment with the Company. The 2025 Inducement Plan provides for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance-based cash and stock awards, and other stock-based awards. The terms and conditions of the 2025 Inducement Plan are substantially similar to the Company’s stockholder-approved 2024 Plan.

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 Exchange 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 the statement of operations and comprehensive loss corresponding to the activity of the related employee. During the three and nine months ended September 30, 2026, the Company recorded$0.7 million and $1.7 millionof stock-based compensation expense in relation to the Exchange Program, respectively.

A summary of the Company’s stock option activity under the 2020 Plan, 2024 Plan, and 2025 Inducement Plan is as follows:

The Company recorded stock-based compensation expense related to employee and non-employee options in the amounts of $0.5 million and $0.9 million for the three and nine months ended September 30, 2026, respectively, and $0.9 million and $3.2 million for the three and nine months ended September 30, 2025, respectively. The weighted-average grant date fair value of options granted for the nine months ended September 30, 2026 and 2025, was$7.71 and $2.57 per share, respectively. The total intrinsic value of options exercised during the nine months ended September 30, 2026 and 2025 was $0.2 million andzero, respectively. Upon the exercise of stock options, the Company will issue new shares of its common stock. As of September 30, 2026, the unrecognized compensation cost related to outstanding employee and non-employee options was $15.7 million and is expected to be recognized as expense over a weighted-average period of 3.6 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 nine months ended September 30, 2026 and 2025, 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. On January 1, 2026,245,955 shares were added to the ESPP reserve. There were 82,939 and 151,275 shares issued under the ESPP during the three and nine months ended September 30, 2026, respectively, and 54,752 and 76,916 shares issued under the ESPP during the three and nine months ended September 30, 2025, respectively.

The ESPP is considered a compensatory plan. The Company recorded related stock-based compensation in the amounts of$0.2 million and $0.4 million for the three and nine months ended September 30, 2026, respectively, and$0.1 million and $0.4 millionfor the three and nine months ended September 30, 2025, 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 Plan, 2024 Plan, and 2025 Inducement 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, 2024 Plan, and 2025 Inducement Plan is as follows:

The Company recorded stock-based compensation expense related to RSUs in the amounts of $2.2 million and $4.9 million for the three and nine months ended September 30, 2026, respectively, and$0.6 million and $1.6 million for the three and nine months ended September 30, 2025, respectively. As of September 30, 2026, the unrecognized compensation cost related to outstanding RSUs was$26.8 million and is expected to be recognized as expense over a weighted-average period of 3.1 years. The total fair value of RSUs vested during the nine months ended September 30, 2026 and 2025 was $9.7 million and $0.5 million, respectively.

Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense by condensed 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 the Research Services 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 Companydidnot incur any research and development expense in connection with the agreements for the three and nine months ended September 30, 2026 and 2025. As of September 30, 2026, and December 31, 2025, the Companyhadno accounts payable and accrued expenses in connection with the GC Cell License Agreements and Research Services Agreement.

In September 2023, the Company and GC Cell amended the AB-201 Agreement (see Note 7). The Company didnot recognize any license and development support-related revenue for the three and nine months ended September 30, 2026 and 2025. As of September 30, 2026, and December 31, 2025, total accounts receivable related to the Amended AB-201 Agreement was zero.

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). There wereno reimbursements for development costs invoiced to GC Cell in connection with the AB-205 Agreement during the three and nine months ended September 30, 2026 and 2025. The Companydid not receive any payments from GC Cell during the three and nine months ended September 30, 2026 and 2025. As of September 30, 2026, and December 31, 2025, the Company hadno receivables from GC Cell recorded in the condensed 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. In connection with the agreement, the Company incurred approximately $13 thousand and $40 thousand in research and development expenses for the three and nine months ended September 30, 2026, respectively, and approximately $13 thousand and $42 thousand for the three and nine months ended September 30, 2025, respectively. As of September 30, 2026, and December 31, 2025, the Company had approximately $35 thousand andzero, respectively, of accounts payable and accrued expenses in connection with the Manufacturing Agreement recorded in the condensed 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 provided 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 didnot incur any research and development expenses in connection with the consulting services from Blackbird for the three and nine months ended September 30, 2026 and 2025. As of September 30, 2026, and December 31, 2025, the Company hadno accounts payable and accrued expenses in connection with the Blackbird Services Agreement recorded in the condensed 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 provided 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 did not incur any research and development expenses in connection with the consulting services from Carnot for the three and nine months ended September 30, 2026. The Company incurred approximately zero and$31 thousand in research and development expenses in connection with consulting services from Carnot for the three and nine months ended September 30, 2025, respectively. As of September 30, 2026, and December 31, 2025, the Company hadno accounts payable and accrued expenses in connection with the Carnot Services Agreement recorded in the condensed balance sheets.

10. Commitments and Contingencies

Operating Leases

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 an average discount rate, which was 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 didnot recognize any sublease income for the three and nine months ended September 30, 2026. The Company recognized sublease income of $0.2 million and $0.6 millionfor the three and nine months ended September 30, 2025.

11. Segment Information

The Company operates and manages its business asone reportable and operating segment, which is the business of developing therapies for autoimmune diseases. The Company’s chief operating decision maker (CODM) is thechief executive officer, who assesses 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.

12. Subsequent Events

For the purposes of the condensed financial statements as of September 30, 2026, and the three and nine months then ended, the Company has evaluated the subsequent events through November 9, 2026, the date the condensed financial statements were issued.

On October 22, 2026, the Company's board of directors approved the discontinuation of the Company's development of AlloNK, as the Company conducts a process to explore strategic alternatives to maximize stockholder value, which includes a plan to implement a reduction of the Company's workforce by approximately 94% of the Company's then-current employee base (the Wind Down). The Company publicly announced this plan on October 27, 2026.

Following the announcement, the Company continues to conduct clinical trial close-out, patient safety monitoring and reporting, preparation of safety findings for potential scientific publication, and management of its in-licensed intellectual property portfolio. The Company is retaining personnel to carry out these activities and support its evaluation of strategic alternatives.

The Company estimates that it will incur between $10 million and $15 million in contract termination and other costs related to the discontinuation and orderly close-out of its AlloNK clinical trials, and between $17 million and $20 million in costs related to the workforce reduction, including severance, benefits, payroll taxes and other termination costs. The Company expects to complete the workforce reduction in the first quarter of 2027 and to incur a significant majority of the costs related to the Wind Down in the fourth quarter of 2026. In addition, the Company expects to incur impairment charges, losses on disposals of assets, contract termination costs and other incremental expenses as a result of the strategic process and the amount of such charges and costs could be material to the Company's results of operations and financial condition. The exact amounts and timing of recognition of such charges and costs is not yet known.

The estimated costs of the Wind Down, as well as the estimated timing of the related costs, are subject to a number of assumptions, and actual results may differ materially. The Company may also incur other charges or cash expenditures not currently contemplated due to events that may occur as a result of, or associated with, the Wind Down.