Financial Analysis

6. Stock-Based Awards 2025 Equity Incentive Plan In April 2025, the Companys board of directors adopted the 2025 Equity Incentive Plan (the 2025 Plan), and in June 2025, the Companys stockholders approved the 2025 Plan. Upon the 2025 Plan becoming effective, no further grants can be made under the Companys 2015 Equity Incentive Plan (the 2015 Plan). The 2025 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, RSU awards, cash-based awards, and other stock-based awards. The number of shares initially reserved for issuance under the 2025 Plan was 25,532,993 shares of common stock, which includes (i) 9,000,000 new shares of common stock, (ii) 3,957,232 shares of common stock that remained available for future grant under the 2015 Plan upon adoption of the 2025 Plan and (iii) up to 12,575,761 shares of common stock underlying outstanding awards under the 2015 Plan and the former 2012 Equity Compensation Plan, which may become available for issuance under the 2025 Plan if and as such awards expire, are otherwise terminated, settled in cash, or repurchased by the Company. The shares of common stock underlying any awards that expire, or are otherwise terminated, settled in cash or repurchased by the Company under the 2025 Plan will be added back to the shares of common stock available for issuance under the 2025 Plan. As of December 31, 2025, 12,442,759 shares remained available for grant under the 2 …

DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock · excerpt; the full note is in the filing

3. Fair Value of Financial Assets and Liabilities The following tables present information about the fair value measurements of the Companys financial assets and liabilities which are measured at fair value on a recurring and non-recurring basis, and indicate the level of the fair value hierarchy utilized to determine such fair values: December 31, 2025 (In thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 16,302 $ $ $ 16,302 Marketable securities 131,403 131,403 Total assets $ 16,302 $ 131,403 $ $ 147,705 Liabilities: Contingent consideration $ $ $ 11,000 $ 11,000 Total liabilities $ $ $ 11,000 $ 11,000 December 31, 2024 (In thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ 22,245 $ $ $ 22,245 Marketable securities 179,326 179,326 Total assets $ 22,245 $ 179,326 $ $ 201,571 Liabilities: Contingent consideration $ $ $ 8,700 $ 8,700 Total liabilities $ $ $ 8,700 $ 8,700 As of December 31, 2025 and 2024, the Companys cash equivalents consisted of money market funds, which were valued based upon Level 1 inputs. The Companys marketable securities as of December 31, 2025 consisted of corporate debt securities and U.S. government debt securities, which were all valued based upon Level 2 inputs. The Companys marketable securities as of December 31, 2024 consisted of commercial paper, corporate debt securities, foreign government agency debt securities, and U.S. government and government agency debt securities, which were all valued based upon Leve …

FairValueDisclosuresTextBlock · excerpt; the full note is in the filing

9. Income Taxes During the years ended December 31, 2025 and 2024, the Company did not record an income tax benefit for net operating losses incurred in each year due to the uncertainty of realizing a benefit from those items. Loss before income taxes is allocated as follows: Year Ended December 31, (In thousands) 2025 2024 U.S. operations $ (64,923) $ (132,065) Foreign operations Loss before income taxes $ (64,923) $ (132,065) A reconciliation of the provision for income taxes to the amount computed by applying the 21% U.S. federal statutory income tax rate to income before income taxes after the adoption of ASU 2023-09 is as follows: (In thousands, except percentages) Year Ended December 31, 2025 Federal taxes at U.S. statutory income tax rate $ (13,634) (21.0) % Tax credits Research and development tax credits (2,531) (3.9) Change in valuation allowance 14,366 22.1 Non-taxable or non-deductible items Non-deductible royalty payments 726 1.1 Other non-deductible items 1,073 1.7 Effective income tax rate $ 0.0 % A reconciliation of the provision for income taxes to the amount computed by applying the 21% U.S. federal statutory income tax rate to income before income taxes for years prior to the adoption of ASU 2023-09 is as follows: Year Ended December 31, 2024 Federal statutory income tax rate (21.0) % State taxes, net of federal benefit (2.1) Impact of state rate changes (1.1) Research and development tax credits (1.1) Excess equity compensation tax benefit, net of officer …

IncomeTaxDisclosureTextBlock · excerpt; the full note is in the filing

December 31, December 31, (In thousands) 2025 2024 Operating Leases: Gross cost $ 4,530 $ 4,530 Accumulated amortization (2,245) (1,688) Other assets $ 2,285 $ 2,842 Current portion of lease liabilities $ 551 $ 481 Other liabilities 1,565 2,117 Total operating lease liabilities $ 2,116 $ 2,598 …

LesseeOperatingLeasesTextBlock · excerpt; the full note is in the filing

Recently Issued Accounting Pronouncements In December 2025, the FASB issued Accounting Standards Update (ASU) No. 2025-12, Interim Reporting (Topic 270): Narrow-Scope Improvements. This standard clarifies interim disclosure requirements and the applicability of Topic 270. The ASU becomes effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. The Company is currently assessing the impact of this ASU. In November 2024, the FASB issued ASU No. 2024-03, Income StatementReporting Comprehensive IncomeExpense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This standard requires disclosure of additional information about specific expense categories in the notes to financial statements on an annual and interim basis. This ASU becomes effective for annual periods beginning after December 15, 2026 and interim periods within annual reporting periods beginning after December 15, 2027. The Company is currently assessing the impact of this ASU. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. The Company adopted ASU No. 2023-09 effective December 31, 2025, on a prospective basis, the impact of which is limited to additional income tax disclosures in the notes to the Companys consolidated financial st …

NewAccountingPronouncementsPolicyPolicyTextBlock · excerpt; the full note is in the filing

10. Related Party Transaction In November 2024, Anand Mehra, a member of the Companys board of directors, purchased 666,666 shares of the Companys common stock at a price per share of $2.25 in connection with a private placement. …

RelatedPartyTransactionsDisclosureTextBlock · excerpt; the full note is in the filing

13. Restructuring Charges In December 2023, the Companys board of directors approved a reduction of the Companys workforce by approximately 46%, which was completed as of December 31, 2024. During the year ended December 31, 2025, the Company made cash severance payments of $0.2 million to impacted employees. During the year ended December 31, 2024, the Company recognized severance expense of $2.7 million and made cash severance payments of $5.6 million to impacted employees. …

RestructuringAndRelatedActivitiesDisclosureTextBlock · excerpt; the full note is in the filing

14. Segment Information The Company operates and reports as one reportable segment, which focuses on identifying and developing innovative therapies to address significant unmet needs for immuno-inflammatory diseases. The segment earns revenue through the licensing of the Companys intellectual property and the provision of laboratory services. All customers and revenue pertaining to the reportable segment are based in the United States. When evaluating the Companys financial performance, the CODM regularly reviews consolidated segment loss, total expense, and direct expenses by project. The CODM allocates resources based on the Companys available cash resources and forecasted expenditures on a consolidated basis. Segment asset information regularly provided to the CODM is consistent with that reported on the consolidated balance sheet with particular emphasis on the Companys available liquidity, including its cash, cash equivalents and marketable securities balances. The following table presents the significant segment expenses and other segment items regularly reviewed by the CODM for the years ended December 31, 2025 and 2024: Year ended December 31, (In thousands) 2025 2024 Contract research $ 1,872 $ 2,541 Licensing revenue 5,954 16,179 Total revenue 7,826 18,720 Cost of revenue 2,091 2,792 Research and development: (1) Bosakitug 13,845 299 ATI-052 7,074 1,895 ATI-2138 4,921 4,209 ATI-9494 5,371 2,360 Discovery 3,872 3,415 Total research and development project expenses 3 …

SegmentReportingDisclosureTextBlock · excerpt; the full note is in the filing

5. Stockholders Equity Preferred Stock As of December 31, 2025 and 2024, the Companys amended and restated certificate of incorporation (as amended, the Charter) authorized the Company to issue 10,000,000 shares of undesignated preferred stock. There were no shares of preferred stock outstanding as of December 31, 2025 and 2024. Common Stock On June 5, 2025, at the 2025 Annual Meeting of Stockholders, the Companys stockholders approved an amendment to the Charter to increase the authorized number of shares of common stock from 200,000,000 shares to 400,000,000 shares. On June 5, 2025, the Company filed a Certificate of Amendment to the Charter with the Secretary of State of the State of Delaware, which became effective upon filing. As of December 31, 2025 and 2024, the Companys Charter authorized the Company to issue 400,000,000 and 200,000,000 shares of $0.00001 par value common stock, respectively. There were 120,499,433 and 107,850,124 shares of common stock issued and outstanding as of December 31, 2025 and 2024, respectively. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Companys stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to any preferential dividend rights of any series of preferred stock that may be outstanding. No dividends have been declared through December 31, 2025. Warrants In November 2024, the Company issued warrants to B …

StockholdersEquityNoteDisclosureTextBlock · excerpt; the full note is in the filing