Zenas BioPharma, Inc. 10-K

Item 8. Financial Statements and Supplementary Data ​ ZENAS BIOPHARMA, INC. INDEX TO CONSOLIDATED FINANCIAL STATEMENTS Consolidated Financial Statements for the Years Ended December 31, 2025 and 2024: ​ ​ ​ ​ Page Report of Independent Registered Public Accounting Firm (PCAOB ID: 42 ) ​ ​ 160 Consolidated Balance Sheets ​ 161 Consolidated Statements of Operations and Comprehensive Loss ​ 162 Consolidated Statements of Stockholders’ Equity ​ 163 Consolidated Statements of Cash Flows ​ 164 Notes to Consolidated Financial Statements ​ 165 ​ 159 Table of Contents ​ Report of Independent Registered Public Accounting Firm ​ To the Shareholders and the Board of Directors of Zenas BioPharma, Inc. ​ Opinion on the Financial Statements We have audited the accompanying consolidated balance sheets of Zenas BioPharma, Inc. (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, changes in convertible preferred stock and stockholders’ equity (deficit) and cash flows for each of the two years in the period ended December 31, 2025, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles. ​ The Company's Ability to Continue as a Going Concern The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the financial statements, the Company has suffered recurring losses from operations, expects to continue to incur operating losses and negative operating cash flows for the foreseeable future, and has stated that substantial doubt exists about the Company’s ability to continue as a going concern. Management's evaluation of the events and conditions and management’s plans regarding these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. ​ Basis for Opinion These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. ​ We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion. ​ Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. ​ /s/ Ernst & Young LLP ​ We have served as the Company’s auditor since 2021. Boston, Massachusetts March 16, 2026 ​ ​ ​ 160 Table of Contents PART I —FINANCIAL INFORMATION Item 1. Financial Statements Zenas BioPharma, Inc. ​ Consolidated Balance Sheets (in thousands, except share and per share amounts) ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Assets ​ ​ ​ ​ ​ ​ ​ ​ Current assets: ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 110,641 ​ $ 319,742 Short-term investments ​ ​ 232,551 ​ ​ 31,024 Restricted cash ​ ​ — ​ ​ 90 Prepaid expenses and other current assets ​ ​ 7,979 ​ ​ 5,067 Total current assets ​ ​ 351,171 ​ ​ 355,923 Property and equipment, net ​ ​ 34 ​ ​ 185 Operating lease right-of-use assets, net ​ ​ 1,354 ​ ​ 1,004 Long-term investments ​ ​ 17,272 ​ ​ — Other non-current assets ​ ​ 13,809 ​ ​ 12,856 Total assets ​ $ 383,640 ​ $ 369,968 Liabilities and Stockholders’ Equity ​ ​ ​ ​ ​ ​ Current liabilities: ​ ​ ​ ​ ​ ​ Accounts payable ​ $ 7,111 ​ $ 17,136 Accrued expenses ​ ​ 54,423 ​ ​ 39,371 Operating lease liabilities, current ​ ​ 1,115 ​ ​ 785 Total current liabilities ​ ​ 62,649 ​ ​ 57,292 Long-term liabilities: ​ ​ ​ ​ ​ ​ Royalty obligation ​ ​ 78,636 ​ ​ — Operating lease liabilities, less current portion ​ ​ 211 ​ ​ 218 Total long-term liabilities ​ ​ 78,847 ​ ​ 218 Total liabilities ​ ​ 141,496 ​ ​ 57,510 Commitments and contingencies (Note 13) ​ ​ ​ ​ ​ ​ Stockholders’ equity: ​ ​ ​ ​ ​ ​ Preferred stock, par value $ 0.0001 per share; 25,000,000 shares authorized and no shares issued and outstanding as of December 31, 2025 and December 31, 2024 ​ ​ — ​ ​ — Common stock, par value $ 0.0001 per share; 175,000,000 shares authorized at December 31, 2025 and December 31, 2024, respectively; 54,485,518 and 41,793,412 shares issued and outstanding as of December 31, 2025 and December 31, 2024, respectively ​ ​ 5 ​ ​ 4 Additional paid-in capital ​ ​ 1,007,331 ​ ​ 699,651 Accumulated other comprehensive (loss) income ​ ​ ( 64 ) ​ ​ 194 Accumulated deficit ​ ​ ( 765,128 ) ​ ​ ( 387,391 ) Total stockholders’ equity ​ ​ 242,144 ​ ​ 312,458 Total liabilities and stockholders’ equity ​ $ 383,640 ​ $ 369,968 ​ ​ The accompanying notes are an integral part of these consolidated financial statements. ​ 161 Table of Contents Zenas BioPharma, Inc. ​ Consolidated Statements of Operations and Comprehensive Loss (in thousands, except share and per share amounts) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ ​ 2025 ​ ​ 2024 Revenue: ​ ​ ​ ​ ​ ​ License and collaboration revenue ​ $ 10,000 ​ $ 5,000 Total revenue ​ ​ 10,000 ​ ​ 5,000 Operating expenses: ​ ​ ​ ​ ​ ​ Research and development ​ ​ 168,063 ​ ​ 139,139 General and administrative ​ ​ 53,322 ​ ​ 29,749 Acquired in-process research and development ​ ​ 171,672 ​ ​ — Total operating expenses ​ ​ 393,057 ​ ​ 168,888 Loss from operations ​ ​ ( 383,057 ) ​ ​ ( 163,888 ) Other income (expense), net: ​ ​ ​ ​ ​ ​ Fair value adjustments to convertible notes ​ ​ — ​ ​ ( 846 ) Interest expense on royalty obligation ​ ​ ( 7,327 ) ​ ​ — Interest income ​ ​ 12,151 ​ ​ 7,973 Other income, net ​ ​ 417 ​ ​ 202 Total other income (expense), net ​ ​ 5,241 ​ ​ 7,329 Loss before income taxes ​ ​ ( 377,816 ) ​ ​ ( 156,559 ) Income tax (benefit) provision ​ ​ ( 79 ) ​ ​ 429 Net loss ​ $ ( 377,737 ) ​ $ ( 156,988 ) Net loss per share - basic and diluted ​ $ ( 8.44 ) ​ $ ( 11.89 ) Weighted-average common stock outstanding - basic and diluted ​ ​ 44,730,052 ​ ​ 13,198,960 Comprehensive loss: ​ ​ ​ ​ ​ ​ Net loss ​ $ ( 377,737 ) ​ $ ( 156,988 ) Other comprehensive income (loss): ​ ​ ​ ​ ​ ​ Unrealized gain on investments ​ ​ 156 ​ ​ 31 Foreign currency translation adjustment ​ ​ ( 414 ) ​ ​ 126 Comprehensive loss ​ $ ( 377,995 ) ​ $ ( 156,831 ) ​ ​ The accompanying notes are an integral part of these consolidated financial statements. ​ ​ ​ ​ ​ 162 Table of Contents Zenas BioPharma, Inc. ​ Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders’ Equity (Deficit) (in thousands, except share data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Seed Series ​ Series A ​ Series B ​ Series C ​ ​ Common Stock ​ ​ ​ ​ ​ ​ ​ ​ ​ Shares ​ ​ ​ Amount ​ Shares ​ ​ ​ Amount ​ Shares ​ ​ ​ Amount ​ Shares ​ ​ ​ Amount ​ ​ Shares ​ ​ ​ Amount ​ ​ ​ Additional Paid-in Capital ​ ​ ​ Accumulated Other Comprehensive Income (Loss) ​ ​ ​ Accumulated Deficit ​ ​ ​ Total Stockholders' Equity (Deficit) Balance as of December 31, 2023 1,785,714 ​ $ 956 ​ 17,589,380 ​ $ 55,840 ​ 81,242,587 ​ $ 193,290 ​ — ​ $ — ​ ​ 1,576,854 ​ $ — ​ $ 4,645 ​ $ 37 ​ $ ( 230,403 ) ​ $ ( 225,721 ) Repurchase of unvested restricted stock awards — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — — ​ — ​ ​ ( 21,172 ) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Issuance of Series C convertible preferred stock, net of issuance costs of $ 619 — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ 116,275,239 ​ ​ 199,526 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — Conversion of convertible preferred stock to common stock upon closing of initial public offering ( 1,785,714 ) ​ ​ ( 956 ) ​ ( 17,589,380 ) ​ ​ ( 55,840 ) ​ ( 81,242,587 ) ​ ​ ( 193,290 ) ​ ( 116,275,239 ) ​ ​ ( 199,526 ) ​ ​ 24,978,715 ​ ​ 2 ​ ​ 449,610 ​ ​ — ​ ​ — ​ ​ 449,612 Issuance of common stock from initial public offering, net of underwriting discounts, commissions and other issuance costs — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 15,220,588 ​ ​ 2 ​ ​ 234,300 ​ ​ — ​ ​ — ​ ​ 234,302 Exercises of common stock options — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 38,427 ​ ​ — ​ ​ 275 ​ ​ — ​ ​ — ​ ​ 275 Stock-based compensation expense — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 10,821 ​ ​ — ​ ​ — ​ ​ 10,821 Unrealized gain on investments — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 31 ​ ​ — ​ ​ 31 Foreign currency translation adjustment — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 126 ​ ​ — ​ ​ 126 Net loss — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 156,988 ) ​ ​ ( 156,988 ) Balance as of December 31, 2024 — ​ $ — ​ — ​ $ — ​ — ​ $ — ​ — ​ $ — ​ ​ 41,793,412 ​ $ 4 ​ $ 699,651 ​ $ 194 ​ $ ( 387,391 ) ​ $ 312,458 Exercises of common stock options — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 510,113 ​ ​ — ​ ​ 4,096 ​ ​ — ​ ​ — ​ ​ 4,096 Purchases of common stock under the Employee Stock Purchase Plan — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 42,768 ​ ​ — ​ ​ 276 ​ ​ — ​ ​ — ​ ​ 276 Issuance of common stock from PIPE offering, net of placement agent fees and other offering costs — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 6,311,030 ​ ​ 1 ​ ​ 111,840 ​ ​ — ​ ​ — ​ ​ 111,841 Equity consideration related to InnoCare License Agreement — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 5,000,000 ​ ​ — ​ ​ 136,671 ​ ​ — ​ ​ — ​ ​ 136,671 Issuance of common stock from ATM offering, net of commissions and other offering costs — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ 828,195 ​ ​ — ​ ​ 28,450 ​ ​ — ​ ​ — ​ ​ 28,450 Stock-based compensation expense — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 26,347 ​ ​ — ​ ​ — ​ ​ 26,347 Unrealized gain on investments — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 156 ​ ​ — ​ ​ 156 Foreign currency translation adjustment — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 414 ) ​ ​ — ​ ​ ( 414 ) Net loss — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ ( 377,737 ) ​ ​ ( 377,737 ) Balance as of December 31, 2025 — ​ $ — $ — ​ $ — ​ — ​ $ — $ — ​ $ — ​ ​ 54,485,518 ​ $ 5 ​ $ 1,007,331 ​ $ ( 64 ) ​ $ ( 765,128 ) ​ $ 242,144 ​ ​ ​ The accompanying notes are an integral part of these consolidated financial statements. ​ 163 Table of Contents Zenas BioPharma, Inc. ​ Consolidated Statements of Cash Flows (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ ​ ​ ​ 2025 ​ ​ ​ ​ 2024 Cash flows from operating activities: ​ ​ ​ ​ ​ ​ Net loss ​ $ ( 377,737 ) ​ $ ( 156,988 ) Adjustments to reconcile net loss to net cash used in operating activities: ​ ​ ​ ​ ​ ​ Acquired in-process research and development ​ ​ 171,672 ​ ​ — Depreciation expense ​ ​ 56 ​ ​ 137 Loss on disposal of property and equipment ​ ​ 107 ​ ​ — Net amortization of premiums and accretion of discounts on investments ​ ​ ( 1,931 ) ​ ​ ( 602 ) Non-cash interest expense on royalty obligation ​ ​ 7,327 ​ ​ — Stock-based compensation expense ​ ​ 26,347 ​ ​ 10,821 Change in fair value of convertible notes ​ ​ — ​ ​ 846 Non-cash lease expense ​ ​ 875 ​ ​ 681 Changes in operating assets and liabilities: ​ ​ ​ ​ ​ ​ Prepaid expenses and other assets ​ ​ ( 3,156 ) ​ ​ ( 7,701 ) Accounts payable ​ ​ ( 10,043 ) ​ ​ 11,740 Accrued expenses ​ ​ 15,052 ​ ​ 22,065 Operating lease liabilities ​ ​ ( 902 ) ​ ​ ( 673 ) Net cash used in operating activities ​ ​ ( 172,333 ) ​ ​ ( 119,674 ) Cash flows from investing activities: ​ ​ ​ ​ ​ ​ Purchases of property and equipment ​ ​ ( 18 ) ​ ​ ( 131 ) Purchases of investments ​ ​ ( 417,755 ) ​ ​ ( 36,421 ) Proceeds from sales and maturities of investments ​ ​ 200,887 ​ ​ 6,000 Product candidate license acquisitions ​ ​ ( 35,000 ) ​ ​ — Net cash used in investing activities ​ ​ ( 251,886 ) ​ ​ ( 30,552 ) Cash flows from financing activities: ​ ​ ​ ​ ​ ​ Proceeds from issuance of Series C convertible preferred stock, net of issuance costs ​ ​ — ​ ​ 178,381 Payment of initial public offering costs ​ ​ — ​ ​ ( 6,334 ) Payments of placement agent fees and other offering costs for PIPE and ATM offerings ​ ​ ( 12,665 ) ​ ​ — Proceeds from royalty obligation ​ ​ 75,000 ​ ​ — Proceeds from exercise of stock options ​ ​ 4,096 ​ ​ 275 Proceeds from issuance of common stock under employee stock purchase plan ​ ​ 276 ​ ​ — Proceeds from issuance of common stock under PIPE offering ​ ​ 120,000 ​ ​ — Proceeds from issuance of common stock under ATM offering, net of commissions ​ ​ 28,573 ​ ​ — Proceeds from initial public offering, net of underwriting discount and commissions ​ ​ — ​ ​ 240,636 Net cash provided by financing activities ​ ​ 215,280 ​ ​ 412,958 Effect of exchange rate changes on cash, cash equivalents and restricted cash ​ ​ ( 252 ) ​ ​ 157 Net (decrease) increase in cash, cash equivalents and restricted cash ​ ​ ( 209,191 ) ​ ​ 262,889 Cash, cash equivalents and restricted cash at beginning of period ​ ​ 319,832 ​ ​ 56,943 Cash, cash equivalents and restricted cash at end of period ​ $ 110,641 ​ $ 319,832 ​ ​ ​ ​ ​ ​ ​ Supplemental disclosure of non-cash investing and financing activities: ​ ​ ​ ​ ​ ​ Right-of-use assets obtained under operating lease arrangements ​ $ 1,500 ​ $ 1,100 Equity consideration for InnoCare license, at fair value ​ $ 136,672 ​ $ — Conversion of convertible preferred stock to common stock upon closing of initial public offering ​ $ — ​ $ 449,612 Conversion of BMS Note into Series C convertible preferred stock ​ $ — ​ $ 21,146 Deferred offering costs in accounts payable and accrued expenses ​ $ 18 ​ $ — ​ ​ ​ ​ ​ ​ ​ Reconciliation of cash, cash equivalents and restricted cash: ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 110,641 ​ $ 319,742 Restricted cash ​ ​ — ​ ​ 90 Total cash, cash equivalents and restricted cash ​ $ 110,641 ​ $ 319,832 ​ ​ The accompanying notes are an integral part of these consolidated financial statements. 164 Table of Contents Zenas BioPharma, Inc. Notes to Consolidated Financial Statements ​ 1. Nature of Business Organization Zenas BioPharma, Inc. (“Zenas” or the “Company”) was incorporated in November 2019 as Zenas BioPharma (Cayman) Limited, an exempted company incorporated in the Cayman Islands with limited liability and commenced operations in 2020. On August 2, 2023, the Company (then known as Zenas BioPharma (Cayman) Limited) de-registered from the Cayman Islands and registered by way of continuation in the State of Delaware. Zenas is a clinical stage global biopharmaceutical company committed to being a leader in the development and commercialization of transformative immunology-based therapies for patients in need. The Company’s goal is to build an immunology and inflammation (“I&I”) focused biopharmaceutical company. The Company has in-licensed and is developing several product candidates for the treatment of various auto-immune and rare diseases. The Company is headquartered in Waltham, Massachusetts and operates in one segment, which is the business of acquiring and developing immune-based therapies for potential commercialization. The Company’s consolidated financial statements include the accounts of its wholly owned subsidiaries which include Zenas BioPharma (HK) Limited (“Zenas HK”), Zenas BioPharma (USA) LLC, Shanghai Zenas Biotechnology Co. Limited, Zenas BioPharma Securities Corp., Zenas BioPharma GmbH, and Zenas BioPharma B.V. Liquidity and Capital Resources Since its inception, the Company has devoted its efforts principally to research and development and raising capital. The Company is subject to risks and uncertainties common to clinical stage companies in the biopharmaceutical industry, including, but not limited to, completing preclinical studies and clinical trials, obtaining regulatory approval for product candidates, market acceptance of products, development by competitors of new technological innovations, dependence on key personnel, the ability to attract and retain qualified employees, reliance on third-party organizations, protection of proprietary technology, compliance with government regulations, and the ability to raise additional capital to fund operations. The Company’s capital to date has been generated from payments received under the Company’s license and collaboration agreement with Bristol-Myers Squibb Company (“BMS”), novation agreement with Tenacia Biotechnology (Hong Kong) Co., Limited (“Tenacia”), license agreement with Zai Lab (Hong Kong) Limited (“Zai”) and a royalty purchase agreement with Royalty Pharma Investments (“Royalty Pharma”) (please see Note 7, License and Collaboration Revenue and Note 9, Royalty Obligation, to these consolidated financial statements). The Company has not generated any revenue from product sales since inception, and its product candidates currently under development will require significant additional research and development efforts, including extensive clinical testing and regulatory approval prior to commercialization. In September 2024, the Company completed its initial public offering (“IPO”), in which the Company issued and sold 15,220,588 shares of its common stock, including 1,985,294 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $ 17.00 per share, for aggregate gross proceeds of $ 258.7 million. The Company received $ 234.3 million in net proceeds after deducting underwriting discounts, commissions and other offering expenses. In connection with the IPO, all outstanding shares of convertible preferred stock converted into 24,978,715 shares of the Company’s common stock. In connection with, and prior to, the Company’s IPO, the Company effected a 1-for- 8.6831 reverse stock split of the Company’s issued and outstanding common stock and adjusted the conversion ratio of all the Company’s outstanding convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in the accompanying consolidated financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect the reverse stock split and the adjustment of the preferred stock conversion ratios. In October 2025, the Company entered into a sales agreement with Jefferies LLC (“Jefferies”) under which the Company may, from time to time, issue and sell shares of our common stock having aggregate sales proceeds of up to $ 200.0 million, in a series of one or more at-the-market equity offerings (“2025 ATM Program”). The Company’s common stock will be 165 Table of Contents sold at prevailing market prices at the time of the sale; and as a result, prices may vary. In 2025, the Company sold 828,195 shares of common stock pursuant to the 2025 ATM program, for net proceeds of $ 28.5 million after deducting commissions and other offering costs. Since January 1, 2026, the Company completed the sales of 2,827,723 shares of common stock under the 2025 ATM Program, for additional information, see Note 18, Subsequent Events to these consolidated financial statements. In October 2025, the Company entered into a securities purchase agreement, for a private placement in public equity (“PIPE”) (the “PIPE Purchase Agreement”) related to the PIPE offering, pursuant to which the Company sold 6,311,030 shares of common stock to certain institutional, accredited investors and certain directors and officers of the Company. The aggregate net proceeds received by the Company were $ 111.8 million, after deducting placement agent fees and other offering costs. The Company has incurred operating losses and negative cash flows since its inception, including net losses of $ 377.7 million and $ 157.0 million in the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, the Company had an accumulated deficit of $ 765.1 million. Management expects operating losses and negative operating cash flows to continue for the foreseeable future. The Company expects that its existing cash, cash equivalents, and investments of $ 360.5 million as of December 31, 2025, together with $ 71.5 million of net proceeds received during the first quarter of 2026 from sales under the ATM Program and the $ 75.0 million of proceeds available from the first tranche under the Company’s debt arrangement with Pharmakon (see Note 18, Subsequent Events, to these consolidated financial statements), will be sufficient to fund its operating and capital expenditure requirements for approximately twelve months following the filing of these financial statements. The Company’s forecast of future cash requirements is subject to significant uncertainties, including, among other factors, the timing and progression of the Phase 3 clinical trials for orelabrutinib, the continued development of obexelimab, and preparations for its potential commercial launch. These uncertainties could require the Company to utilize additional cash resources, or to use existing resources sooner than currently anticipated. ​ As a result of these uncertainties and their potential impact on the Company’s projected funding requirements, management concluded there is substantial doubt about the Company’s ability to continue as a going concern for at least twelve months following the filing date of these financial statements. The Company expects to finance future operations through private or public equity financings, debt financings, or other capital resources. However, there can be no assurance that such financing will be available when needed, on acceptable terms, or at all. Failure to obtain additional capital as required could have a material adverse effect on the Company’s financial condition and its ability to execute its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so. ​ The accompanying consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Accordingly, the consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. ​ 2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying consolidated financial statements include the operations of the Company and its wholly-owned subsidiaries. All intercompany accounts, transactions, and balances have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). 166 Table of Contents Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, expenses, and related disclosures. The Company bases its estimates on historical experience, known trends and other market- specific factors or other relevant factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis using such factors and adjusts those estimates and assumptions as facts and circumstances dictate. Actual results may differ from those estimates or assumptions. Significant estimates in these consolidated financial statements include estimates made in connection with accrued research and development expenses, stock-based compensation, pre-IPO valuations of common stock, and the liability related to the sale of future royalties including the estimation of future payments and the related non-cash interest expense. Cash and Cash Equivalents The Company considers all highly liquid investments with original or remaining maturity from the date of purchase of three months or less to be cash equivalents. Cash equivalents may include money market funds, corporate debt securities, U.S government agency notes and overnight deposits. Investments The Company classifies all investments with a remaining maturity when purchased of greater than three months as “available-for-sale”. Available-for-sale securities with a remaining maturity of greater than one year are classified as non-current assets. Available-for-sale securities are carried at fair value based upon market prices at period end, with the unrealized gains and losses included in accumulated other comprehensive loss as a component of stockholders’ equity (deficit) until realized. The amortized cost of investments in this category is adjusted for amortization of premiums and accretions of discounts over the life of the instrument. Realized gains and losses are determined using the specific identification method and are included in other income (expense). The Company reviews its portfolio of investments, using both quantitative and qualitative factors, to determine if declines in fair value below cost have resulted from a credit-related loss. If the decline in fair value is due to credit-related factors, a loss is recognized in other income (expense). Restricted Cash Restricted cash consists of cash held as collateral for a letter of credit the Company issued as a security deposit for its lease of office space in Waltham, MA, which was terminated in January 2025. Amounts are reported as non-current unless restrictions are expected to be released in the next 12 months. Deferred Offering Costs The Company capitalizes legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as other non-current assets until such financings are consummated. After consummation of the equity financing, these costs will be recorded in stockholders’ equity (deficit) as a reduction of additional paid-in-capital generated as a result of the offering. If the Company terminates its plan for an equity financing, any costs deferred will be expensed immediately. As of December 31, 2025, the Company had $ 0.7 million in deferred offering costs which were included in other assets. No deferred offering costs were recorded as of December 31, 2024. Segment Reporting Operating segments are defined as components of an enterprise for which separate and discrete information is available for evaluation by the chief operating decision-maker in deciding how to allocate resources and assess performance. The Company has one reportable segment focused on the research and development of precision immunology-based therapies. The Company’s chief operating decision-maker (the “CODM”), its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of making operating decisions, assessing financial performance, and allocating resources. As of December 31, 2025 and 2024, the Company’s long-lived assets held outside of the U.S. were immaterial. 167 Table of Contents For additional information, see Note 17, Segment Information to these consolidated financial statements. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and investments. The Company attempts to minimize the risks related to cash, cash equivalents and investments by investing in a broad range of financial instruments, as defined by the Company’s investment policy. The Company has established guidelines related to the quality of the institutions, financial instruments and allowable investments. The Company minimizes credit risk by choosing only highly rated financial institutions as counterparties. Significant Suppliers The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs, including preclinical and clinical studies and testing. While the drug substances used in product candidates are manufactured by more than one supplier, the Company relies on a single third-party manufacturer to manufacture and supply it with its requirements for the drug product related to its programs. These programs could be adversely affected by a significant interruption in the supply of drug substance and drug product. Translation of Foreign Currency The functional currency for most of our foreign subsidiaries is their local currency. For our non-U.S subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the average foreign currency exchange rates for the period. Adjustments resulting from the translation of the financial statements of our foreign subsidiaries into U.S. dollars are excluded from our determination of net loss and are recorded in accumulated other comprehensive income (loss), as a separate component of equity. For foreign subsidiaries where the functional currency of assets and liabilities differs from their local currency, non-monetary assets and liabilities are translated at the rate of the exchange in effect on the date assets were acquired while monetary assets and liabilities are translated at current rates of exchange as of the balance sheet date. Income and expense items are translated at the average foreign currency rates for the period. Translation adjustments of these subsidiaries are included in other (income) expense, net in our consolidated statements of income. Realized and unrealized foreign currency transaction gains were $ 0.3 million and transaction losses were $ 0.2 million for the years ended December 31, 2025 and 2024, respectively. Fair Value Measurements ASC Topic 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the assets or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the price that would be received to sell an asset or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tiered value hierarchy that distinguishes between the following: Level 1— Quoted market prices in active markets for identical assets or liabilities. Level 2— Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3— Unobservable inputs for the asset or liability (i.e. supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). 168 Table of Contents To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgement. Accordingly, the degree of judgement exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The majority of the Company’s financial assets have been classified as Level 1. Our financial assets (which typically include cash equivalents and marketable debt securities) have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, utilizing third-party pricing services or option pricing valuation models. The pricing services utilize industry standard valuation models, including both income and market-based approaches and observable market inputs to determine value. These observable market inputs may include reportable tables, benchmark yields, broker quotes, bids, offers, current spot rates and other industry and economic events. For additional information, see Note 3, Fair Value Measurements to these consolidated financial statements. Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. When such events occur, the Company compares the carrying amount of the assets to their undiscounted expected future cash flows. If this comparison indicates there is an impairment, the amount of the impairment is calculated as the difference between the carrying value and fair value. To date, no such impairments have been recognized. Property and Equipment Property and equipment are recorded at cost. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets ( three to seven years ). Leasehold improvements are amortized over the shorter of their useful lives or lease terms using the straight-line method. Major replacements and improvements are capitalized, while general repairs and maintenance are expensed as incurred. Royalty Obligation When the Company maintains significant continuing involvement in generating the underlying cash flows, royalty financings are recognized as obligations. Payments received are recorded as the principal amount of the obligation on the consolidated balance sheet as long-term liabilities. The carrying amount of the obligation is accreted to reflect the total expected royalty and related payments, using the effective interest method. As royalties and other related payments are made, the outstanding royalty obligation will be reduced over the estimated term of the arrangement. ​ The royalty obligation, effective interest rate, and corresponding interest expense are determined based on the Company’s estimate of future anticipated royalty payments under the arrangement. These estimates are reassessed at the end of each reporting period according to the Company’s latest projections. Should these estimated cash flows change as a result of this review, the Company will recalculate the effective interest rate and adjust the accretion of interest on the royalty obligation prospectively. Any additional funding received will also be treated as an obligation, with a prospective adjustment to the effective interest rate applied upon receipt of such funds. ​ For additional information, see Note 9, Royalty Obligation to these consolidated financial statements. ​ License and Collaboration Revenue The Company enters into license and collaboration arrangements with third parties, under which the Company licenses or may license rights to certain of the Company’s product candidates and may perform research and development services in connection with such arrangements. The terms of these arrangements typically include payment of one or more of the following: non-refundable, upfront fees; reimbursement of research and development costs; development, clinical, regulatory and commercial sales milestone payments, and royalties on net sales of licensed products. ​ 169 Table of Contents At contract inception, the Company analyzes its collaboration and license arrangements to assess whether such arrangements are within the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple units of account, the Company first determines which units of the collaboration are deemed to be within the scope of ASC 808 and which units of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”). ​ Contracts are considered to be collaborative arrangements when they satisfy the following criteria defined in ASC 808: (i) the parties to the contract must actively participate in the joint operating activity and (ii) the joint operating activity must expose the parties to the possibility of significant risks and rewards, based on whether or not the activity is successful. For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election. Payments received from or made to a partner that are the result of a collaborative relationship with a partner, instead of a customer relationship, such as co-development activities, are recorded as a reduction or increase to research and development expense, respectively. ​ For the units of account within the scope of ASC 606, to determine the appropriate amount of revenue to be recognized for the arrangements, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect consideration it is entitled to in exchange for the goods or services it transfers to the customer. ​ The promised goods or services in the Company’s arrangements typically consist of a license to the Company’s intellectual property and research and development services. The Company provides options to additional items in such arrangements, which are accounted for as separate contracts when the customer elects to exercise such options, unless the option provides a material right to the customer. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer and are considered distinct when (i) the customer can benefit from the good or service on its own or together with other readily available resources and (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on its own or whether the required expertise is readily available and whether the goods or services are integral or dependent to other goods or services in the contract. ​ The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of potential payment and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected value method to estimate the amount expected to be received based on which method best predicts the amount expected to be received. The amount of variable consideration that is included in the transaction price may be constrained and is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. ​ The Company’s contracts often include development and regulatory milestone payments that are assessed under the most likely amount method and constrained if it is probable that a significant revenue reversal would occur. Due to the uncertainty of research and development and regulatory based milestones that are not within the control of the Company, payment becomes probable upon achievement. At the end of each reporting period, the Company re-evaluates the probability of achievement of such development and clinical milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license and collaboration revenue in the period of adjustment. Any amounts due to the Company but not received as of period-end will be recorded to other current assets. 170 Table of Contents ​ For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of the Company’s collaboration arrangements. ​ The Company allocates the transaction price based on the estimated standalone selling price. The Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the stand-alone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs including a reasonable margin. Variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated are consistent with the amounts the Company would expect to receive for the satisfaction of each performance obligation. The consideration allocated to each performance obligation is recognized as revenue when control is transferred for the related goods or services. ​ Research and Development Expenses Research and development costs include (i) employee-related expenses, including salaries, benefits, and stock-based compensation expense; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization (“CROs”) agreements and consultants; (iii) costs associated with preclinical activities and (iv) lab supplies, lab expenses and an allocation of rent, depreciation, and infrastructure. Costs incurred in connection with research and development activities are expensed as incurred. ​ Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data, such as patient enrollment or clinical site activations, provided by the Company’s clinical sites and vendors. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved, and experience with similar contracts. Milestone payments under license agreements are accrued, with a corresponding expense being recognized, in the period in which the milestone is determined to be probable of achievement and the related amount is reasonably estimable. The Company monitors each of these factors and adjusts estimates accordingly. The Company has not experienced any material differences between accrued costs and actual costs incurred since its inception. ​ Asset Acquisitions and Acquired In-Process Research and Development Expense The Company accounts for acquisitions of assets or a group of assets that do not meet the definition of a business as asset acquisitions based on the cost to acquire the asset or group of assets, which include certain transaction costs. In an asset acquisition, the cost to acquire is allocated to the identifiable assets acquired and liabilities assumed based on their relative fair values as of the acquisition date. No goodwill is recorded in an asset acquisition. Assets that are acquired in an asset acquisition for use in research and development activities that have an alternative future use are capitalized as in process research and development (“IPR&D”). Acquired IPR&D that has no alternative future use as of the acquisition date is recognized as acquired IPR&D expense as of the acquisition date. The Company will recognize additional acquired IPR&D expenses in the future if and when the Company becomes obligated to make contingent milestone payments under the terms of the agreements by which it acquired the IPR&D assets. The Company classifies payments made for the acquisition of IPR&D assets, whether capitalized or expensed, as investing activities on its statement of cash flows. ​ Contingent consideration in the form of milestone payments related to IPR&D with no alternative future use are charged to expense when the related milestone is achieved and becomes payable. When milestone payments are in the form of equity consideration, the Company evaluates whether the payment should be treated as a liability or 171 Table of Contents meets the definition of a derivative. When liability or derivative treatment is not required, such milestone payments are recorded at fair value as a component of equity and not remeasured. ​ For additional information, see Note 8, License Agreements, to these consolidated financial statements. Comprehensive Loss Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss consists of net loss and other comprehensive loss. During the years ended December 31, 2025 and 2024, the Company’s only element of other comprehensive loss was foreign currency translation adjustments. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of use lease assets (“ROU assets”), current portion of lease obligations and long-term lease obligations on the Company’s consolidated balance sheet. Assets subject to finance leases are included in property and equipment, and the related lease obligation is included in other current liabilities and other long-term liabilities on the Company’s consolidated balance sheet. Lease assets are tested for impairment in the same manner as long-lived assets used in operations. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense, while expense for financing leases is recognized as depreciation expense (classified as an operating expense) and interest expense (classified as a non-operating expense) using the effective interest method. The Company has elected the short-term lease recognition exemption for short-term leases, which allows the Company not to recognize lease liabilities and ROU assets on the consolidated balance sheet for leases with an original term of twelve months or less. ROU assets represent the Company’s right to use an underlying asset for the lease term, and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating lease liabilities and their corresponding ROU assets are initially recognized based on the present value of lease payments over the expected remaining lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise the option. Certain adjustments to the ROU asset may be required for items such as incentives received from the lessor. The interest rate implicit in lease contracts is typically not readily determinable. Therefore, the Company utilizes its incremental borrowing rate to discount lease payments. The incremental borrowing rate reflects the fixed rate at which the Company could borrow, on a collateralized basis, the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the ROU assets for straight-line rent expense, or any incentives received and remeasures the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company generally accounts for non-lease components together with lease components. The Company expenses variable payments included in a lease arrangement as such expenses are incurred. For additional information, see Note 6, Leases , to these consolidated financial statements. Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes , which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. The Company determines its deferred tax assets and liabilities based on differences between financial reporting and tax bases of assets and liabilities, which are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all deferred tax assets will not be realized. The Company accounts for uncertain tax positions recognized in the consolidated financial statements by prescribing a “more likely than not” threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. There are no unrecognized tax benefits included in the Company’s consolidated balance sheets as of December 31, 2025 and 2024. The Company’s policy is to recognize interest and penalties related to income tax 172 Table of Contents matters in income tax expense. The Company has not recognized interest or penalties related to uncertain tax positions in its consolidated statements of operations and comprehensive loss since inception. Stock-Based Compensation The Company grants stock-based awards to employees, non-employee consultants and members of its board of directors (the “Board”). Stock-based compensation is recognized as expense for each stock-based award based on its estimated fair value on the date of grant. The Company’s share-based payments include stock options, grants of restricted common stock and restricted stock units (“RSUs”). The value of the award is recognized as expense on a straight-line basis over the requisite service period, and expense is adjusted for pre-vesting forfeitures in the period in which the forfeitures occur. Stock-based compensation expense is classified in the accompanying consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified or in which the award recipients service payments are classified. The Company estimates the fair value of each RSUs at its grant date based on the estimated fair value of the Company’s common stock on that date as determined by the Board. The Company estimates the fair value of stock option awards on the grant date using a Black-Scholes option pricing model. The Company estimates the expected option lives using the simplified method, volatility using historical stock prices of peer companies, the risk-free rates using the U.S Treasury yield curve in effect with a remaining term equal to the expected term and dividend yield based on the Company’s history of paying no dividends and the expectations of paying no cash dividends in the foreseeable future. Prior to the Company’s IPO, the fair value of the Company’s common stock on the date of grant was determined by the Board, taking into consideration its most recently available third-party valuations of common stock as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the grant date. For additional information, see Note 11, Stock-Based Compensation , to these consolidated financial statements. Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock. Net loss per share is calculated using the two- class method, which is an earnings allocation formula that determines net loss per share for the holders of the Company’s common shares and participating securities. The Company’s convertible preferred stock contained participation rights in any dividend paid by the Company and was deemed to be a participating security. Net loss attributable to common stockholders and participating preferred shares are allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods in which a net loss is recorded. ​ Diluted net loss per share is computed using the more dilutive of (a) the two-class method or (b) the if- converted method. The weighted-average number of common shares included in the computation of diluted net loss per share gives effect to all potentially dilutive common equivalent shares, including outstanding stock options and preferred stock. ​ Common stock equivalent shares are excluded from the computation of diluted net loss per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share is the same as basic net loss since dilutive common shares are not assumed to have been issued if their effect is antidilutive. The Company reported a net loss for the years ended December 31, 2025 and 2024. ​ Recent Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740)—Improvements to Income Tax Disclosures (“ASU 2023-09”) , which requires a company to expand its existing income tax disclosures, specifically related to the rate reconciliation and income taxes paid. ASU 2023-09 is effective for the Company beginning in fiscal year 2025. This 173 Table of Contents standard became effective for the Company for the annual reporting period ended December 31, 2025, and was adopted using the prospective method. The adoption of this standard resulted in additional disclosure of the rate reconciliation. The adoption did not have a material impact on the consolidated financial position or results of operations. See Note 13, Income Taxes , to these consolidated financial statements, for our updated income tax presentation. In November 2024, the FASB issued 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (“ASU 2024-03”) , which requires entities to disclose additional information about specific expense categories in the notes to the financial statements. ASU 2024-03 is effective annual for periods beginning after December 15, 2026 and for interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. ASU 2024-03 may be applied retrospectively or prospectively to the financial statements. The Company is currently evaluating the impact of ASU 2024-03 on the consolidated financial statements and related disclosures. ​ From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that we adopt as of the specified effective date. Unless otherwise discussed, we do not believe that the adoption of recently issued standards have or may have a material impact on our consolidated financial statements or disclosures. ​ 3. Fair Value Measurements The following table presents information about the Company’s assets and liabilities that are regularly measured and carried at fair value and indicate the level within the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2025 Description ​ ​ ​ ​ Total Carrying Value ​ ​ Quoted Prices in Active Market (Level 1) ​ ​ ​ ​ Significant Other Observable Inputs (Level 2) ​ ​ ​ ​ Significant Other Observable Inputs (Level 3) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash ​ $ 13,038 ​ $ 13,038 ​ $ — ​ $ — Money market funds ​ ​ 97,603 ​ ​ 97,603 ​ ​ — ​ ​ — Short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ ​ 5,959 ​ ​ — ​ ​ 5,959 ​ ​ — Corporate debt securities ​ ​ 44,299 ​ ​ — ​ ​ 44,299 ​ ​ — Government securities ​ ​ 182,293 ​ ​ 182,293 ​ ​ — ​ ​ — Long-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities ​ ​ 1,467 ​ ​ — ​ ​ 1,467 ​ ​ — Government securities ​ ​ 15,805 ​ ​ 15,805 ​ ​ — ​ ​ — Total assets ​ $ 360,464 ​ $ 308,739 ​ $ 51,725 ​ $ — 174 Table of Contents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2024 Description ​ ​ ​ ​ Total Carrying Value ​ ​ Quoted Prices in Active Market (Level 1) ​ ​ ​ ​ Significant Other Observable Inputs (Level 2) ​ ​ ​ ​ Significant Other Observable Inputs (Level 3) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash ​ $ 19,070 ​ $ 19,070 ​ $ — ​ $ — Money market funds ​ ​ 300,672 ​ ​ 300,672 ​ ​ — ​ ​ — Short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial paper ​ ​ 3,315 ​ ​ — ​ ​ 3,315 ​ ​ — Corporate debt securities ​ ​ 8,601 ​ ​ — ​ ​ 8,601 ​ ​ — Government securities ​ ​ 19,108 ​ ​ 19,108 ​ ​ — ​ ​ — Total assets ​ $ 350,766 ​ $ 338,850 ​ $ 11,916 ​ $ — ​ There have been no material impairments of our assets measured and carried at fair value during the years ended December 31, 2025 and 2024. In addition, there have been no changes in valuation techniques as of December 31, 2025 and 2024. The fair value of Level 1 instruments classified as money market funds and government securities are valued using quoted market prices in active markets. The fair value of Level 2 instruments classified as short-term investments was determined using other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date and fair value is determined using models or other valuation methodologies. There were no transfers between levels during the years ended December 31, 2025 and 2024. The short and long-term investments are classified as available-for-sale securities. As of December 31, 2025, the remaining contractual maturities of the available-for-sale securities were 1 to 15 months, and the balance in the Company’s accumulated other comprehensive income was comprised solely of activity related to the Company’s available-for-sale securities. There were no realized gains or losses recognized on the sale or maturity of available-for-sale securities during the years ended December 31, 2025 and 2024. As a result, the Company did not reclassify any amounts out of accumulated other comprehensive income for the same period. The Company had a limited number of available-for-sale securities in insignificant loss positions as of December 31, 2025, which the Company does not intend to sell and has concluded will not be required to sell before recovery of amortized cost for the investment maturity. The following table summarizes the available-for-sale securities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2025 ​ ​ Amortized Cost ​ ​ Gross Unrealized Gains ​ ​ Gross Unrealized Losses ​ ​ Fair Value Commercial paper $ 5,957 ​ $ 2 ​ $ — ​ $ 5,959 Corporate debt securities ​ 45,740 ​ ​ 28 ​ ​ ( 2 ) ​ ​ 45,766 Government securities ​ 197,939 ​ ​ 162 ​ ​ ( 3 ) ​ ​ 198,098 Total $ 249,636 ​ $ 192 ​ $ ( 5 ) ​ $ 249,823 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2024 ​ ​ Amortized Cost ​ ​ Gross Unrealized Gains ​ ​ Gross Unrealized Losses ​ ​ Fair Value Commercial paper $ 3,311 ​ $ 4 ​ $ — ​ $ 3,315 Corporate debt securities ​ 8,589 ​ ​ 12 ​ ​ — ​ ​ 8,601 Government securities ​ 19,093 ​ ​ 17 ​ ​ ( 2 ) ​ ​ 19,108 Total $ 30,993 ​ $ 33 ​ $ ( 2 ) ​ $ 31,024 ​ 175 Table of Contents Certain short-term debt securities with original maturities of less than 90 days are included in cash and cash equivalents on the consolidated balance sheets and are not included in the table above. ​ ​ ​ ​ 4. Other Assets Other assets consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Clinical trial deposits ​ $ 12,882 ​ $ 12,639 Deferred offering costs ​ ​ 709 ​ ​ — Other ​ ​ 218 ​ ​ 217 Total other assets ​ $ 13,809 ​ $ 12,856 ​ ​ 5. Accrued Expenses Accrued expenses consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2025 ​ ​ ​ 2024 External research, development and manufacturing expenses $ 38,855 ​ $ 29,338 Employee compensation and benefits ​ 13,080 ​ ​ 8,308 Professional and consultant fees ​ 1,500 ​ ​ 1,265 Income taxes payable ​ 118 ​ ​ 211 Other ​ 870 ​ ​ 249 Total accrued expenses $ 54,423 ​ $ 39,371 ​ ​ 6. Leases ​ T he Company has various leases for office space, which are accounted for as operating leases and generally have terms of less than two years in length, some of which have the option to renew. The Company recognizes monthly operating lease expense on a straight-line basis over the term of the lease as general and administrative expenses in the consolidated statements of operations and comprehensive loss. Variable lease expense relates primarily to office lease common area maintenance, insurance, and property taxes, is expensed as incurred, and is excluded from the calculation of the lease liabilities and right-of-use assets. For the years ended December 31, 2025 and 2024, the Company incurred variable lease expense of $ 0.3 million and $ 0.1 million, respectively. ​ Supplemental balance sheet information related to operating lease assets and liabilities was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2025 ​ ​ 2024 Operating lease assets ​ $ 1,354 ​ $ 1,004 Operating lease liabilities ​ $ 1,326 ​ $ 1,003 Weighted average remaining term in years ​ ​ 1.3 ​ ​ 1.3 Weighted average discount rate used to measure lease liabilities ​ ​ 8.33 % ​ ​ 10.99 % ​ For the years ended December 31, 2025 and 2024, the Company recorded $ 1.0 million and $ 0.9 million in operating lease expense (recorded in general and administrative expenses in the Company’s consolidated statements of operations and comprehensive loss), respectively. ​ ​ 176 Table of Contents The minimum lease payments under the Company’s operating leases are expected to be as follows: ​ ​ ​ ​ ​ Fiscal Year ​ ​ ​ Amount 2026 ​ $ 1,163 2027 ​ ​ 229 Thereafter ​ ​ — Total future minimum lease payments ​ ​ 1,392 Less: imputed interest ​ ​ ( 66 ) Total operating lease liabilities ​ $ 1,326 ​ During the years ended December 31, 2025 and 2024, the amount of right-of-use assets obtained under new operating lease arrangements was $ 1.5 million and $ 1.1 million, respectively. For years ended December 31, 2025 and 2024, the Company made $ 1.0 million and $ 0.9 million in lease payments, respectively. ​ ​ 7. License and Collaboration Revenue License and Collaboration Agreement with Bristol-Myers Squibb In August 2023, the Company entered into a license and collaboration agreement (the “BMS Agreement”) with BMS, under which the Company granted BMS an exclusive license to (i) develop, manufacture (subject to the Company’s rights to be the exclusive manufacturer for BMS for a certain period of time), commercialize or otherwise exploit obexelimab and any biological product (irrespective of presentations, formulations or dosages) containing obexelimab but not any of the Company’s other proprietary active ingredient (the “BMS Product”) into Japan, South Korea, Taiwan, Singapore, Hong Kong and Australia (collectively, the “BMS Territory”) and (ii) develop and manufacture obexelimab and the BMS Product outside the BMS Territory provided that obexelimab and the BMS Product are solely used in the BMS Territory. Pursuant to the BMS Agreement, BMS paid the Company a one-time non-refundable upfront cash payment of $ 50.0 million. The Company is entitled to receive further separate development, regulatory milestone payments from BMS of up to approximately $ 79.5 million. The Company is also entitled to receive one-time sales milestone payments up to $ 70.0 million upon BMS achieving certain net sales milestones in a given year in the BMS Territory. The Company is also eligible to receive tiered high single-digit to low double-digit royalties on net sales in the BMS Territory, subject to specified reductions. The Company will continue to perform and oversee the ongoing Phase 3 trial of obexelimab in the IgG4-RD indication and BMS will participate in the performance of the study. BMS also has the right to participate in other global clinical studies that the Company chooses to perform. Pursuant to such global studies, including the IgG4-RD study, the Company and BMS have defined roles with specified activities assigned to each party in their respective jurisdictions. These activities are overseen by a joint steering committee, which has equal representation of the parties. BMS will fund their pro rata share of the total global study costs up to a specified percentage of the patients enrolled in the study from the BMS Territory. BMS is responsible for the development and commercialization of obexelimab within the BMS Territory, including the performance of any local studies within its jurisdiction that it chooses to perform, while the Company retains responsibility for the development and commercialization for the remainder of the world. The Company is responsible for manufacturing the clinical supply and commercial supply of obexelimab, each at cost plus single-digit margin. The Company evaluated the terms of the BMS Agreement to determine whether it is a collaborative arrangement in the scope of ASC 808. The Company concluded that the BMS Agreement is a collaborative arrangement under ASC 808 as both parties are active participants in the global clinical trial and are exposed to significant risks and rewards of those activities. The Company determined that the BMS Agreement contained two material components: (i) the license granted to BMS to develop, manufacture and commercialize obexelimab within the BMS Territory, and related activities in the BMS Territory, including manufacturing and (ii) the global development of obexelimab, which at execution, solely related to the ongoing Phase 3 trial for IgG4-RD. The Company used criteria specified in ASC 606 to determine whether the components of the BMS Agreement are performance obligations to a customer and concluded that BMS is the Company’s 177 Table of Contents customer for the license and related activities in the BMS Territory under ASC 606. The global development activities under the agreement do not represent a transaction with a customer and reimbursement payments received by the Company for global development activities are accounted for as a reduction of the related research and development expenses. The Company recorded $ 5.5 million and $ 6.0 million as a reduction to research and development expenses during the years ended December 31, 2025 and 2024, respectively, with $ 1.2 million and $ 2.0 million of outstanding receivable, included in prepaid expenses and other current assets on the Company’s consolidated balance sheet as of December 31, 2025 and 2024, respectively. The Company evaluated the license and related activities under ASC 606 as these transactions are considered transactions with a customer, and identified four material promises at the outset of the BMS Agreement, which consists of (i) the exclusive license, (ii) the initial technology transfer, (iii) clinical manufacturing supply related to development in the BMS Territory and (iv) commercial manufacturing supply related to commercialization within the BMS Territory. The Company determined that the exclusive license and initial technology transfer were not distinct from each other, as the exclusive license has limited value without the corresponding technology transfer. As such, for the purposes of ASC 606, the Company determined that the two material promises, the exclusive license and the initial technology transfer, should be combined into one distinct performance obligation. The Company further evaluated the material promise associated with the clinical manufacturing supply and the commercial manufacturing supply, within the BMS Territory, concluding that because BMS is not obligated to purchase any minimum amount, the clinical manufacturing supply and commercial manufacturing supply represent a purchase option and not a performance obligation. The Company further concluded that the customer option is not priced at a significant and incremental discount at the execution of the arrangement and therefore does not represent a material right. Therefore, each of the clinical and commercial manufacturing activities were excluded as performance obligations at the outset of the arrangement. The transaction price of the BMS Agreement was determined to be $ 50.0 million, which consisted of the upfront cash payment, and was allocated to the one combined performance obligation. The other potential consideration, which includes development, regulatory, and sales milestone payments that the Company is eligible to receive were excluded from the transaction price, as all milestones were not deemed probable of achievement and were therefore fully constrained. The Company issued the BMS Note in connection with the BMS Agreement, and the BMS Note was recorded at fair value separate from the transaction price of the BMS Agreement. In May 2024, the BMS Note was settled through the issuance of convertible preferred stock, which was converted to common stock in September 2024. The Company reevaluates the transaction price at the end of each reporting period as uncertain events are resolved or other changes in circumstances occur, and if necessary, the Company adjusts its estimate of the transaction price, and any addition to the transaction price would be recognized as revenue when it becomes probable that inclusion would not lead to a significant revenue reversal. The Company evaluated the license under ASC 606 and concluded that the license is a functional intellectual property license. The Company determined that BMS benefited from the license along with the initial technology transfer at the time of the transfer, and therefore the related performance obligation is satisfied at a point in time. The Company satisfied the performance obligation through delivery of the license and initial technology transfer and therefore recognized the upfront payment of $ 50.0 million as revenue during year ended December 31, 2023. The Company did no t recognize revenue under this arrangement during the years ended December 31, 2025 or 2024, as no milestones were achieved or deemed probable of achievement, and as such, all remaining milestones remained fully constrained and excluded from the transaction price. Tenacia Biotechnology Co. Novation Agreement In October 2024, the Company entered into a novation agreement with Tenacia, under which the Company transferred its rights and obligations under the agreements with Dianthus to Tenacia (the “Tenacia Agreement”). Pursuant to the Tenacia Agreement, the Company, transferred all the ZB005 inventory, analytical methods and manufacturing records generated, under the Dianthus Option Agreement and the License Agreement (collectively the “Dianthus Agreements”), to Tenacia, for the exclusive right to research, develop, manufacture and commercialize products within China, Hong King, Macau and Taiwan (“greater China”). As a result of the Tenacia Agreement, the Company has no further obligations to Dianthus pursuant to the Dianthus Agreement. 178 Table of Contents Pursuant to the Tenacia Agreement, Tenacia paid the Company a one-time non-refundable upfront cash payment of $ 5.0 million. The Company is entitled to receive further development, regulatory and sales milestones from Tenacia of up to approximately $ 86.0 million if certain milestones are successfully achieved. The Company evaluated the terms of the Tenacia Agreement and determined it is within the scope of ASC 606. The Company identified the following promises in the Tenacia Agreement that were evaluated under the scope of ASC 606: (i) transfer of the license, (ii) assignment of all rights, title and interests in ZB005 inventory, manufacturing records, analytical methods and draft IND component, (iii) services to be performed in accordance with manufacturing technology transfer and (iv) transfer, up to one year after the effective date, of any tangible embodiments of know-how that was not previously provided. The Company also evaluated whether certain options outlined in the Tenacia Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options conveyed a material right to Tenacia and, therefore, are not considered separate performance obligations within the Tenacia Agreement. The Company assessed the above promises and determined that the license for ZB005, asset transfer and technology transfer are a combined distinct performance obligation within the scope of ASC 606. The future technology know-how transfer services, for one year after the effective date, is a promise that is separately identifiable. The Company determined the likelihood of Tenacia requesting additional know-how transfer to be remote and any requests to require minimal resource allocation, as the Company has concluded all work on ZB005 within greater China. As such, the Company considered the continued know-how transfer to be immaterial in the context of the promises. Therefore, the license, asset transfer and technology transfer represent a single performance obligation within the scope of ASC 606 at contract inception. The Company concluded that the transaction price of $ 5.0 million was allocated to the combined performance obligation, which was recognized upon delivery prior to December 31, 2024. The Company used the most likely amount method to estimate variable consideration and estimated that the most likely amount for each potential developmental and regulatory variable consideration milestone payment under the agreement is zero, as achievement of those milestones is uncertain and susceptible to factors outside the Company’s control. Accordingly, all such milestone payments were excluded from the transaction price. Management will reevaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, will adjust the transaction price as necessary. Sales based milestones structured on the level of sales, were also excluded from the transaction price, as the license is deemed to be the predominant item to which the sales relate. The Company will recognize such revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). As of December 31, 2025, no milestones were achieved or deemed probable of achievement. License Agreement with Zai Lab (Hong Kong) Limited In January 2025, the Company entered into a license agreement (the “Zai License Agreement”), with Zai, under which the Company granted Zai an exclusive sublicense to develop, manufacture and commercialize ZB001 and related programs in greater China. Under the Zai License Agreement, Zai will be responsible for conducting all research and development activities, manufacturing, regulatory and commercialization in greater China. ​ Pursuant to the Zai License Agreement, Zai paid the Company a one-time non-refundable upfront cash payment of $ 10.0 million. The Company is entitled to receive further development, regulatory and sales milestones from Zai up to approximately $ 117.0 million if certain milestones are successfully achieved, with passthrough obligations of $ 21.0 million due to Viridian. The Company is also eligible to receive tiered royalties on net sales in greater China, ranging from the low to mid-single digits, net of passthrough obligations due to Viridian. The Company evaluated the terms of the Zai License Agreement and determined it is within the scope of ASC 606. The Company identified the following promises in the Zai License Agreement that were evaluated under the scope of ASC 606: (i) transfer of the license for ZB001, (ii) licensed technology transfer (iii) licensed material transfer and (iv) continued licensed technology transfer. The Company also evaluated whether certain options outlined in the Zai License Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options 179 Table of Contents conveyed a material right to Zai or were immaterial and, therefore, are not considered separate performance obligations within the Zai License Agreement. The Company assessed the above promises and determined that the license for ZB001 and technology transfer are a combined distinct performance obligation within the scope of ASC 606. The licensed material transfer and the continued technology know-how transfer services are promises that are separately identifiable and considered to be distinct. The Company determined the transfer of the licensed materials and continued technology know-how transfer services were immaterial in the context of the contract based on the minimal resources required to fulfill the obligations and the estimated standalone selling price of the licensed materials. Therefore, the sublicense and technology transfer represent a single performance obligation at contract inception. The Company concluded that the transaction price of $ 10.0 million was allocated to the combined performance obligation, which was recognized upon delivery prior to March 31, 2025. The Company used the most likely amount method to estimate variable consideration and estimated that the most likely amount for each potential developmental and regulatory variable consideration milestone payment under the agreement is zero, as achievement of those milestones is uncertain and susceptible to factors outside the Company’s control. Accordingly, all such milestone payments were excluded from the transaction price. Management will reevaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, will adjust the transaction price as necessary. Sales and royalty based milestones structured on the level of sales, were also excluded from the transaction price, as the license is deemed to be the predominant item to which the transaction price relates. The Company will recognize such milestone and royalty revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). ​ As of December 31, 2025, no milestones were achieved or deemed probable of achievement. ​ 8. License Agreements License Agreements with Xencor, Inc. 2020 Xencor Agreement In September 2020, the Company entered into a license agreement (the “2020 Xencor Agreement”) with Xencor, Inc. (“Xencor”), to obtain (i) an exclusive, royalty-bearing, sublicensable worldwide license under certain patent rights controlled by Xencor and (ii) a non-exclusive payment bearing license under certain know-how controlled by Xencor to research, develop, manufacture, market and sell three antibody product candidates, including ZB002. The 2020 Xencor Agreement became effective in November 2020, upon the Company’s issuance of 5,041,542 shares of its Series A Preferred Stock. ​ The Company is required to pay Xencor tiered royalties on annual net sales of successfully commercialized products, including ZB002 and ZB004. The royalty percentage rates vary by geographic areas as defined in the 2020 Xencor Agreement and range from the mid-single digits to mid-teens. ​ The Company is also obligated to reimburse Xencor for third-party costs incurred for certain patent filings, prosecution and maintenance as further specified in the 2020 Xencor Agreement. During the years ended December 31, 2025 and 2024, the Company did not incur any such reimbursable costs. ​ 2021 Xencor Agreement In May 2021, the Company entered into a license agreement with Xencor (the “2021 Xencor Agreement”), under which the Company obtained an (i) exclusive, royalty-bearing, sublicensable worldwide license under certain patent rights controlled by Xencor and (ii) a non-exclusive payment bearing license under certain know-how controlled by Xencor to research, develop, manufacture, market and sell obexelimab. The 2021 Xencor Agreement became effective in November 2021, upon the execution of an amendment to the 2021 Xencor Agreement. ​ 180 Table of Contents In 2023, the Company incurred a $ 10.0 million development milestone, which was recorded as acquired IPR&D expense in the consolidated statements of operations and comprehensive loss. The Company is obligated to make regulatory milestone payments up to $ 75.0 million and one-time sales milestone payments up to $ 385.0 million upon achieving milestone events of net sales in a given calendar year in the territory equal to certain threshold amounts. In addition, the Company is required to pay Xencor tiered royalties on annual net sales of successfully commercialized products utilizing obexelimab, with the royalty percentages varying based on regions and ranging from the mid-single digits to the mid-teens. ​ During the year ended December 31, 2025 and 2024, the Company did not incur any expense related to milestones or any expenses related to reimbursable patent-related costs. ​ License Agreement with Viridian Therapeutics, Inc. In October 2020, the Company entered into a license agreement (“the Viridian Agreement”) with Viridian Therapeutics, Inc (“Viridian”)., to obtain an exclusive, royalty-bearing, sublicensable license to research, develop, manufacture, market and sell certain antibody product candidates based on Viridian’s proprietary technology. The Company’s license rights are limited to non-oncology indications and are limited to China, Hong Kong, Macau and Taiwan (“Zenas Territories”). The Viridian Agreement, as amended, obligates the Company to make a development and sales milestone payments to Viridian, totaling $ 21.0 million, based on achievement of certain specified development and sales milestones, as well as royalties on net sales. ​ In January 2025, the Company entered the Zai License Agreement under which the Company granted Zai an exclusive sublicense to develop, manufacture and commercialize ZB001 and related programs in greater China. In connection with the Zai License Agreement, the Company assigned the Viridian Supply Agreement to Zai. For additional information on the Zai License Agreement, please see License Agreement with Zai Lab (Hong Kong) Limited in Note 7, License and Collaboration Revenue to these consolidated financial statements. ​ During the years ended December 31, 2025 and 2024, the Company recognized an immaterial amount of expenses, related to Viridian contract manufacturing organization (“CMO”) costs. Viridian has agreed to reimburse the Company for certain services the Company performs on Viridian’s behalf, with reimbursements being recorded as a reduction in research and development expenses. During the years ended December 31, 2025 and 2024, the Company recorded $ 0.2 million and $ 1.7 million in reimbursable expenses, respectively. During the year ended December 31, 2025 and 2024, the Company did no t incur any expenses related to milestones. ​ License Agreement with InnoCare Pharma Inc. In October 2025, the Company entered into a License Agreement (the “InnoCare License Agreement”) with InnoCare Pharma Inc. (“InnoCare”). Under the InnoCare License Agreement, InnoCare granted the Company exclusive rights to develop, manufacture, and commercialize: i) orelabrutinib, in the multiple sclerosis (“MS”) field worldwide, and in all non-oncology indications outside Greater China and Brunei, Burma, Cambodia, Timor-Leste, Indonesia, Laos, Malaysia, Philippines, Singapore, Thailand and Vietnam (“Southeast Asia”), ii) ZB021 (an IL-17AA/AF inhibitor) in all fields of use worldwide, excluding Greater China and Southeast Asia and iii) ZB022 (a TYK2 inhibitor) in all fields of use worldwide. The Company also obtained certain non-exclusive rights to perform development and manufacturing activities in Greater China and Southeast Asia to support each program in its respective licensed territories. Pursuant to the InnoCare License Agreement, the Company made one-time non-refundable upfront cash payments totaling $ 35.0 million and issued 5,000,000 shares of common stock to InnoCare (“InnoCare Shares”) in exchange for these rights. The Company is also required to make an additional one-time non-refundable cash payment of $ 25.0 million and issue an additional 2,000,000 shares of common stock to InnoCare upon the occurrence of Zenas’ Phase 3 clinical trial for orelabrutinib in any indication other than primary progressive MS, or by March 31, 2026, upon the occurrence of certain specified events, whichever comes first (the “Near-term Milestone”) . In addition, the Company has agreed to make one-time, potential near-term milestone payments of $ 20.0 million each, upon the achievement of certain regulatory milestones for ZB021 and ZB022 (the “Regulatory Milestones”). 181 Table of Contents The Company is further obligated to pay future regulatory and commercial milestones of up to $ 723.0 million related to orelabrutinib, and future development, regulatory, and commercial milestones of up to $ 656.0 million, inclusive of the two $ 20.0 million Regulatory Milestones specified above, for each preclinical compound if certain milestones are successfully achieved. In addition, the Company is obligated to pay royalties on net sales at rates ranging from high-single digits to high-teens for orelabrutinib, and mid-single digits to mid-teens for the preclinical compounds. The Company simultaneously entered into a Subscription Agreement and a Registration Rights Agreement with InnoCare related to the shares of common stock issued and to be issued. The Subscription Agreement provides for transfer restrictions on the InnoCare Shares and other customary representations, warranties and covenants that were made solely for the benefit of the parties to the Subscription Agreement. The Registration Rights Agreement requires us to, among other things, prepare and file a registration statement to register the InnoCare Shares. The Company evaluated the transaction and concluded that the acquired license rights did not constitute a business, as no substantive processes or other activities were acquired. As the acquired assets do not have alternative future use, the consideration paid was expensed as acquired IPR&D at the execution date of the arrangement. The consideration for the license rights, which consisted of the upfront cash payment of $ 35.0 million, the issuance of 5,000,000 shares of common stock upon execution of the agreement, and the 2,000,000 shares of common stock issuable upon achievement of the Near-term Milestone. The Near-term Milestone shares met the equity classification criteria and were measured at fair value as of the agreement execution date, reflecting the probability of achieving the milestone and applicable share restrictions, excluding those related to the holder. As a result, total IPR&D expense of $ 171.7 million was recorded in the consolidated statement of operations and comprehensive loss. The remaining milestones are payable solely in cash and will be recognized upon achievement; no such milestones had been achieved as of December 31, 2025. Under the InnoCare License Agreement, the Company was obligated to reimburse InnoCare for certain clinical trial startup costs and Investigational New Drug (“IND”) enabling activities which were incurred prior to and after the effective date of the agreement. As of December 31, 2025, the Company incurred $ 3.1 million of expense, of which $ 2.2 million was paid related to the reimbursable costs to InnoCare related to the acquired programs. ​ 9. Royalty Obligation In September 2025, the Company and Royalty Pharma Investments 2019 ICAV (“Royalty Pharma”) entered into the Revenue Participation Right Purchase and Sale Agreement (the “Royalty Purchase Agreement”). Pursuant to the Royalty Purchase Agreement, the Company received a $ 75.0 million upfront payment in exchange for which Royalty Pharma purchased the right to receive, for each calendar quarter, (i) 5.5 % of net sales of obexelimab products sold by the Company and its affiliates worldwide, (ii) 5.5 % of net sales of obexelimab products sold by licensees of Zenas and its affiliates in the U.S., the United Kingdom and the European Union, (iii) 25 % of royalty income payable to Zenas or any of its affiliates on sales of obexelimab products in countries other than the U.S., the United Kingdom, and in the European Union by its licensees pursuant to out-licenses less royalty payments payable by Zenas to Xencor Inc. and (iv) 25 % of non-royalty income attributable to obexelimab products payable to Zenas or any of its affiliates by its licensees (other than certain milestone payments payable by Bristol-Myers Squibb) pursuant to out-licenses and allocated to countries other than the U.S., the United Kingdom and in the European Union. The Royalty Purchase Agreement provides for an additional $ 225.0 million of payments to be paid to the Company by Royalty Pharma upon the occurrence of certain triggering events which includes (1) $ 75.0 million payable upon the achievement of certain milestones with respect to Zenas’ INDIGO Phase 3 Trial, noting the Company is not currently eligible for this milestone, (2) $ 75.0 million payable following receipt of marketing approval for obexelimab from the U.S. Food and Drug Administration (the “FDA”) for the treatment of IgG4-Related Disease on or before a specified date and (3) $ 75.0 million payable following receipt of marketing approval for obexelimab from the FDA for the treatment of systemic lupus erythematosus on or before a specified date. The Company accounted for the Royalty Purchase Agreement as a debt financing, primarily because it has significant continuing involvement in generating the future revenue on which the royalty payments are based. The $ 75.0 million upfront payment received was recorded as a liability, net of issuance costs of $ 3.7 million. The effective interest rate was determined based on the Company’s projections of future payments to Royalty Pharma. The Company will evaluate the 182 Table of Contents estimated timing and amount of future royalty payments each reporting period and will revise the effective interest rate prospectively if those estimates change materially. The fair value of the liability approximates the carrying value and was determined based on the current estimate of the timing and amount of expected future royalty payments expected to be paid over the estimated term of the Royalty Purchase Agreement, which are subject to significant estimation uncertainty and are based on various assumptions made by the Company. These assumption inputs are determined to be Level 3 inputs in the fair value hierarchy as they involve significant unobservable inputs and judgment. ​ The following table shows the activity for the royalty obligation during the year ended December 31, 2025 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount Proceeds from royalty obligation ​ $ 75,000 Issuance costs ​ ​ ( 3,691 ) Interest expense related to royalty obligation ​ ​ 7,327 Royalty obligation as of December 31, 2025 ​ $ 78,636 Effective interest rate ​ ​ 30.7 % ​ ​ 10. Common Stock The Company is authorized to issue 175,000,000 shares of common stock $ 0.0001 par value. The voting, dividend and liquidation rights of the holders of the Company’s common stock were subject to and qualified by the rights, powers and preference of the holders of any preferred stock then issued and outstanding. In October 2025, the Company entered into a sales agreement with Jefferies under which the Company could, from time to time, issue and sell shares of its common stock having aggregate sales proceeds of up to $ 200.0 million, under the 2025 ATM Program. Jefferies is not required to sell any specific share amounts but acts as the Company’s sales agent, using commercially reasonable efforts consistent with its normal trading and sales practices. Sales sold pursuant to the sales agreement will be sold pursuant to a shelf registration statement on Form S-3-ASR (Registration No. 333-290777), which became automatically effective upon filing on October 8, 2025. The Company’s common stock will be sold at prevailing market prices at the time of the sale; and as a result, prices may vary. As of December 31, 2025, the Company sold 828,195 shares of common stock under the 2025 ATM Program, with net proceeds of approximately $ 28.5 million, after deducting commissions and other offering costs. In October 2025, the Company entered into the PIPE Purchase Agreement related to the PIPE offering, pursuant to which the Company sold (i) 6,262,112 shares of common stock to certain institutional and accredited investors at a price of $ 19.00 per share and (ii) 48,918 shares of common stock to certain directors and officers of the Company at a price of $ 20.85 per share. Sales sold pursuant to the PIPE Purchase Agreement were sold pursuant to a shelf registration statement on Form S-3-ASR (Registration No. 333-290999), which became automatically effective upon filing on October 21, 2025. As of December 31, 2025, the Company received, net proceeds of $ 111.8 million from the PIPE offering, after deducting placement agent fees and other offering costs. The holders of the common stock are entitled to one vote for each share of common stock held at all meetings of stockholders (and written actions in lieu of meetings), and there are no cumulative voting rights. 183 Table of Contents The Company had reserved the following shares of common stock for the potential conversion of outstanding stock options: ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Options to purchase common stock ​ 10,675,615 ​ 8,706,197 Remaining shares reserved for future issuance ​ 431,863 ​ 359,399 RSUs ​ 599,675 ​ — Employee stock purchase plan ​ 773,122 ​ 397,956 Total ​ 12,480,275 ​ 9,463,552 ​ ​ ​ ​ ​ ​ 11. Stock-Based Compensation 2020 Plan In August 2020, the Company’s sole director adopted the 2020 Equity Incentive Plan (the “2020 Plan”). Upon the effectiveness of the 2024 Plan (as defined below), the Company ceased granting additional awards under the 2020 Plan and the remaining available shares for future grant were transferred to the 2024 Plan. The 2020 Plan allowed the Company to grant stock options, restricted stock awards, RSUs and other stock-based awards to employees, officers, directors and consultants of the Company and subsidiaries. As of December 31, 2025, 3,217,355 shares of stock options were outstanding under the 2020 Plan. 2024 Plan In September 2024, the Board adopted the 2024 Equity Incentive Plan (the “2024 Plan”), which became effective immediately prior to the effectiveness of the registration statement for the Company’s IPO. The 2024 Plan provides for the award of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, unrestricted stock, RSUs and other stock-based awards. The number of shares reserved and available for issuance under the 2024 Plan will automatically increase each January 1, beginning on January 1, 2025 through January 1, 2034, by the number of shares equal to the lesser of (i) five percent of the aggregate number of shares of common stock outstanding as of such date, and (ii) a number of shares as may be determined by the Board on or prior to such date. As of December 31, 2025, 431,863 shares of common stock were available for issuance under the 2024 Plan. On January 1, 2026, the shares available for issuance under the 2024 Plan was increased to 3,156,138 . 2026 Inducement Plan In December 2025, the Company’s board of directors adopted the 2026 Inducement Plan (the “2026 Inducement Plan”), which became effective December 10, 2025. The 2026 Inducement Plan provides for the award of non-qualified stock options and other awards under the 2026 Inducement Plan to persons not previously an employee or director of the Company, or following a bona fide period of non-employment, as an inducement material to such persons entering the employment of the Company. The grants constitute “employment inducement grants” in accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules and are issued outside of the 2024 Plan. The inducement grants include non-statutory stock options to purchase shares of the Company’s common stock and RSUs. The inducement grants have terms and conditions consistent with those set forth under the 2024 Plan and vest under the same respective vesting schedules as stock option awards and RSUs granted under the 2024 Plan. The Company’s initially reserved 1,000,000 shares of common stock for the issuance of awards under the 2026 Inducement Plan. As of December 31, 2025, 1,000,000 shares of common stock were available for issuance under the 2026 Inducement Plan. 184 Table of Contents Stock Options The Company has granted stock-based awards with either service or performance based vesting conditions. Compensation expense related to awards to employees and directors with service based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Compensation expense related to awards to employees with performance based vesting conditions is recognized based on the grant date fair value once the achievement of the performance condition is probable. From time to time, the Company grants equity awards to newly hired employees as an inducement to enter into employment with the Company. The grants constitute "employment inducement grants" in accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules and are issued outside of the 2024 or 2026 Plans. The inducement grants include non-statutory stock options to purchase shares of the Company's common stock and RSUs. The inducement grants are granted under individual inducement agreements and have terms and conditions consistent with those set forth under the 2024 Plan and vest under the same respective vesting schedules as stock option awards and RSU awards granted under the 2024 Plan. The inducement grants are included in the stock option award tables below. As of December 31, 2025, the Company granted 1,062,000 non-statutory stock options as inducement grants. No inducement grants were awarded during the year ended December 31, 2024. ​ The table below presents the weighted-average assumptions used in estimating the fair values of stock options granted during the years ended December 31, 2025 and 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2025 ​ 2024 Risk-free interest rate ​ 4.11 % ​ 3.80 % Expected term (in years) ​ 6.05 ​ ​ 6.07 ​ Expected volatility ​ 94.88 % ​ 94.31 % Expected dividend yield ​ 0.00 % ​ 0.00 % ​ The weighted-average grant date fair value of options granted during the years ended December 31, 2025 and 2024, was $ 10.30 and $ 11.38 per share, respectively. The fair value is being expensed over the associated service period of the award on a straight-line basis based on the grant date fair value or once the achievement of the performance condition is probable. The following table presents a summary of the Company’s stock option activity and related information: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Shares ​ ​ ​ Weighted - Average Exercise Price ​ ​ ​ Weighted-Average Remaining Contractual Term (in years) ​ ​ ​ Aggregate Intrinsic Value (in thousands) Outstanding - December 31, 2024 ​ 8,706,197 ​ $ 13.21 ​ ​ ​ $ 2,104 Granted ​ 3,031,450 ​ $ 13.14 ​ ​ ​ ​ ​ Exercised ​ ( 510,113 ) ​ $ 8.03 ​ ​ ​ $ 4,884 Forfeited or cancelled ​ ( 551,919 ) ​ $ 12.80 ​ ​ ​ ​ ​ Outstanding - December 31, 2025 ​ 10,675,615 ​ $ 13.46 ​ 8.60 ​ $ 243,979 Options vested and exercisable as of December 31, 2025 ​ 3,210,911 ​ $ 12.31 ​ 7.94 ​ $ 77,051 Options vested and expected to vest as of December 31, 2025 ​ 10,675,615 ​ $ 13.46 ​ 8.60 ​ $ 243,979 ​ The aggregate intrinsic value of the stock options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock for those stock options that had an exercise price lower than the fair value of the Company’s common stock as of the measurement date of December 31, 2025. There were 510,113 options 185 Table of Contents exercised for the year ended December 31, 2025, resulting in total proceeds of $ 4.1 million and 38,427 options exercised for the year ended December 31, 2024, resulting in total proceeds of $ 0.3 million. Restricted Stock Units The Company granted to certain employees RSUs that are subject to time-based vesting conditions, that vest equally over four years , assuming continued employment. RSUs with time-based vesting conditions are valued on the grant date using the grant date market value price of the underlying shares of the Company’s common stock. The Company did not grant any RSU’s in 2024. The following table summarizes the Company’s RSU activity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Shares ​ ​ ​ ​ Weighted - Average Grant Date Fair Value Unvested as of December 31, 2024 ​ — ​ $ — Granted ​ 612,875 ​ $ 14.18 Vested ​ — ​ $ — Forfeited ​ ( 13,200 ) ​ $ 11.94 Unvested as of December 31, 2025 ​ 599,675 ​ $ 14.23 ​ No RSUs vested during the year ended December 31, 2025. As of December 31, 2025, unrecognized stock-based compensation expense was $ 83.7 million, which is expected to be recognized over a weighted average period of 2.8 years. The total fair value of equity awards vested during the years ended December 31, 2025 and 2024 was $ 27.1 million and $ 4.6 million, respectively. The Company recognized stock-based compensation expense related to the issuance of equity awards to employees, directors and consultants in the consolidated statement of operations as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ ​ 2025 ​ ​ 2024 Research and development ​ $ 8,838 ​ $ 4,066 General and administrative ​ ​ 17,509 ​ ​ 6,755 Total stock-based compensation expense ​ $ 26,347 ​ $ 10,821 ​ Employee Stock Purchase Plan In September 2024, the Board adopted the 2024 Employee Stock Purchase Plan (the “ESPP”), which became effective immediately prior to the effectiveness of the registration statement for the Company’s IPO. The number of shares of common stock available under the ESPP will automatically increase on January 1st of each year, beginning on January 1, 2025 through January 1, 2034, by the number of shares equal to the lesser of (i) one percent of the aggregate number of shares of common stock outstanding as of such date, and (ii) a number of shares as may be determined by the Board on or prior to such date, up to a maximum of 1,000,000 shares in the aggregate per year. During the year ended December 31, 2025, there were 42,768 shares issued under the ESPP. As of December 31, 2025, a total of 773,122 shares were available for future issuance under the ESPP. On January 1, 2026, the shares of common stock reserved for issuance under the ESPP was 1,317,977 . ​ ​ ​ ​ 12. Net Loss Per Share The Company’s potentially dilutive securities, which include stock options, RSUs and the 2,000,000 shares of common stock to be issued to InnoCare , have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the 186 Table of Contents following shares from the computation of diluted net loss per share as of December 31, 2025 and 2024 because including them would have had an anti-dilutive effect: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2025 ​ 2024 Options to purchase common stock ​ 10,675,615 ​ 8,706,197 Unvested restricted stock units ​ 599,675 ​ — Common stock to be issued to InnoCare ​ 2,000,000 ​ — ​ ​ 13. Income Taxes The Company adopted ASU 2023-009, Income Taxes (Topic 740): Improvements to Income Tax Disclosures on a prospective basis for the year ended December 31, 2025. ​ The following table presents income (loss) from ccontinuing operations before income taxes during the years ended December 31, 2025 and 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Income (loss) from continuing operations ​ ​ ​ ​ ​ ​ U.S. loss ​ $ ( 388,509 ) ​ $ ( 160,918 ) Non-U.S. income ​ 10,693 ​ 4,359 Total ​ $ ( 377,816 ) ​ $ ( 156,559 ) ​ The significant components of income tax expense (benefit) attributable to income from continuing operations for the years ended December 31, 2025 and 2024 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Current tax (benefit) provision ​ ​ ​ ​ Federal ​ $ — ​ $ 123 State ​ ( 79 ) ​ 306 Foreign ​ — ​ — Total current income tax (benefit) provision ​ ( 79 ) ​ 429 Deferred tax expense (exclusive of effects of other components listed below) ​ ​ ​ ​ Federal, state and foreign ​ ​ — ​ ​ — Total deferred tax expense ​ $ — ​ $ — Total income tax (benefit) provision ​ $ ( 79 ) ​ $ 429 ​ 187 Table of Contents Income tax expense (benefit) attributable to income (loss) from continuing operations for the year ended December 31, 2025 differed from the amounts computed by applying the statutory U.S. Federal income tax rate of 21 percent to pretax income (loss) from continuing operations as a result of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2025 ​ U.S. Federal statutory income tax (benefit) at 21 % $ ( 79,342 ) ​ 21.00 % Domestic federal ​ ​ ​ ​ ​ Tax Credits ​ ​ ​ ​ ​ R&D Credit ​ ( 10,791 ) ​ 2.86 ​ Changes in valuation allowance ​ 90,239 ​ ( 23.88 ) ​ Nontaxable or nondeductible items ​ ( 36 ) ​ 0.01 ​ Cross-border tax laws ​ 2,246 ​ ( 0.59 ) ​ Other reconciling items ​ ( 41 ) ​ 0.01 ​ Domestic state income taxes, net of federal effect ​ ( 108 ) ​ 0.03 ​ Foreign tax effects: ​ ​ ​ ​ ​ Other foreign jurisdictions ​ ( 2,246 ) ​ 0.59 ​ Total $ ( 79 ) ​ 0.03 % ​ Below is the tabular rate reconciliation previously disclosed for the year ended December 31, 2024: ​ ​ ​ ​ ​ ​ December 31, 2024 ​ ​ Percentage of income before income taxes Federal statutory income tax rate ​ ​ ​ 21.0 % State income taxes, net of federal benefit 6.4 Change in valuation allowance ( 32.3 ) IP transfer ​ ( 0.3 ) ​ Research and development tax credits 4.9 Foreign tax rate differential 0.2 Other adjustments ( 0.2 ) Effective income tax rate ( 0.3 ) % ​ The following table presents the cash paid for income taxes, net of refunds recevied, by jurisdiction pursuant to the disclosure requirements of ASU 2023-09 for the year ended December 31, 2025 (in thousands): ​ ​ ​ ​ December 31, 2025 ​ ​ ​ U.S. federal $ — U.S. state and local ​ Massachusetts 13 California ​ 1 Other * ​ 1 Subtotal $ 15 Foreign ​ Other — Total $ 15 * The amount of income taxes paid during the year does not meet the five percent disaggregation threshold. ​ The only state or local juridiction that contributes to the majority, greater than 50%, of the tax effect of the state and local income tax category, is Massachusetts. 188 Table of Contents The following table presents the tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferrred tax liabilities at December 31, 2025 and 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ ​ 2024 Deferred tax assets: ​ ​ ​ ​ Net operating loss carryforwards ​ $ 65,455 ​ $ 29,605 Capitalized research and development ​ 30,641 ​ 39,716 Research and development tax credits ​ 25,737 ​ 14,292 Stock-based compensation ​ 10,017 ​ 4,016 Royalty obligation ​ ​ 22,492 ​ ​ — Milestone payments ​ 46,697 ​ 442 Accruals ​ 3,074 ​ 1,886 Other ​ 817 ​ 901 Total deferred tax assets ​ 204,930 ​ 90,858 Valuation allowance ​ ​ ( 203,870 ) ​ ​ ( 90,295 ) Deferred tax assets, net of valuation allowance ​ $ 1,060 ​ $ 563 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Prepaids and other ​ ( 1,060 ) ​ ( 563 ) Total deferred tax liabilities ​ ( 1,060 ) ​ ( 563 ) Net deferred tax asset ​ $ — ​ $ — ​ ASC Topic 740 requires a valuation allowance to reduce the deferred tax assets reported if, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. After consideration of all the evidence, both positive and negative, the Company has recorded full valuation allowances against its domestic and foreign deferred tax assets as of December 31, 2025, because management has determined that it is more likely than not that these assets will not be realized. The valuation allowance increased by $ 113.6 million to $ 203.9 million as of December 31, 2025, primarily due to additional net operating losses related to the U.S. and non-U.S. entities. On July 4, 2025, the One Big Beautiful Bill Act (“OBBBA”) was enacted, introducing several significant U.S. income tax provisions that impact the Company. Of these provisions, companies are no longer required to capitalize domestic research and development expenditures. However, foreign expenditures of this nature must continue to be capitalized and amortized over a fifteen year period. Due to the operations of the Company, the Company does not anticipate electing to accelerate the deduction for the previously capitalized domestic research and development expenditures. The Company will continue to monitor the impact of OBBBA and anticipated guidance from the U.S. Department of Treasury. The balance of previously capitalized applicable costs associated with research and development expenditures was $ 30.6 million as of December 31, 2025. As of December 31, 2025, the Company had approximately $ 211.2 million and $ 210.4 million of U.S. federal and state net operating loss (“NOL”) carryforwards, respectively. As of December 31, 2024, the Company had approximately $ 75.5 million and $ 65.0 million of U.S. federal and state NOL carryforwards. The federal NOL carryforwards do not expire, but they may be limited in their usage to an annual deduction equal to 80 % of annual taxable income. The state NOL carryforwards expire in 20 years , starting in 2042. The federal and state NOL carryforwards are fully offset by valuation allowances. As of December 31, 2025 and 2024, the Company had $ 43.7 million and $ 54.2 million of foreign NOL carryforwards, respectively. The foreign NOL carryforwards are fully offset by valuation allowances. The China NOL carryforwards expire at various dates beginning in 2026 through 2028 for tax purposes, while the Hong Kong NOLs may be carried forward indefinitely for tax purposes. The Company files income tax returns in the U.S., as well as various state and foreign jurisdictions. The Company is not currently under any income tax examinations. All tax years generally remain open in each jurisdiction. ​ As of December 31, 2025, the Company had $ 24.1 million and $ 2.1 million in federal and state general business or research and development tax credit carryforwards. As of December 31, 2024, the Company had $ 13.3 million and $ 1.2 million in 189 Table of Contents federal and state general business or research and development tax credit carryforwards. These carryforwards are subject to review and possible adjustment by the appropriate taxing authorities. The federal and state research credit carryforwards expire in 20 years and 15 years , respectively, starting in 2036. The federal and state tax credit carryforwards are fully offset by valuation allowances. There have been no unrecognized tax benefits since the Company’s inception. The Company’s policy is to record estimated interest and penalties related to the underpayment of income taxes as a component of its income tax provision. As of December 31, 2025 and 2024, the Company had no accrued interest or penalties related to uncertain tax positions and since inception, no amounts have been recognized in the Company’s consolidated statements of operations and comprehensive loss. Under the provisions of Section 382 of the Internal Revenue Code of 1986, as amended, utilization of the NOLs and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 due to ownership change limitations that have occurred previously or that could occur in the future in accordance with Section 382, as well as similar state provisions. These ownership changes may limit the amount of NOLs and research and development tax credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. If a change in control as defined by Section 382 has occurred at any time since the Company’s formation, utilization of its NOLs or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term tax-exempt rate, which could then be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the NOLs or research and development tax carryforwards before their utilization. ​ 14. Commitments and Contingencies Operating Leases The Company has entered into arrangements for leases of office space; for additional information see Note 6, Leases to these consolidated financial statements. License Agreements The Company entered into licenses agreement under which it is obligated to make fixed and contingent payments; for additional information see Note 8, License Agreements to these consolidated financial statements. Royalty Obligation The Company entered into a royalty purchase agreement under which it is obligated to make contingent payments related to future net sales and royalty income of obexelimab; for additional information see Note 9, Royalty Obligation to these consolidated financial statements. Other Contracts The Company has entered into agreements with certain vendors for the provision of services that the Company is not contractually able to terminate for convenience and thereby avoid any and all future obligations to the vendors. Under such agreements, the Company is contractually obligated to make certain minimum payments to the vendors, with the exact amounts in the event of termination to be based on the timing of the termination and the exact terms of the agreement. As of December 31, 2025, our total non-cancellable clinical manufacturing contract payment obligations are $ 17.7 million of which the full obligation is payable within 12 months. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and certain officers that will 190 Table of Contents require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or services as directors. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not currently aware of any indemnification claims and had not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2025. Litigation and Other Proceedings The Company may periodically become subject to legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which the Company is focused. As of December 31, 2025, the Company was not subject to any material legal proceedings which would reasonably be expected to have a material adverse effect on the Company’s financial results. ​ 15. Employee Benefit Plans Effective June 2020, the Company adopted the Zenas BioPharma 401(k) Plan (the “401(k) Plan”) for its employees, which is designed to be qualified under Section 401(k) of the Internal Revenue Code. Eligible employees are permitted to contribute to the 401(k) Plan within statutory and 401(k) Plan limits. As of January 1, 2025, the Company matches participant contributions pursuant to the terms of the 401(k) Plan, which contributions are limited to a percentage of the participant’s compensation contributed to the plan. For the year ended December 31, 2025, the Company made $ 1.0 million matching contributions to the 401(k) Plan. For the year ended December 31, 2024, the Company made a one-time contribution of $ 0.1 million to the 401(k) Plan. ​ 16. Related Party Transactions Xencor, Inc. The Company has obtained exclusive, worldwide licenses from Xencor to research, develop, manufacture, market and sell three antibody product candidates pursuant to two license agreements. The Company has concluded that Xencor is a related party, due to the issuance of convertible preferred stock in December 2020 and April 2023. In connection with the completion of the IPO, in September 2024, all outstanding shares of preferred stock converted into shares of common stock. As of December 31, 2025, Xencor held less than 10 % of shares of the Company’s outstanding common stock. Viridian Therapeutics, Inc. The Company has obtained a license from Viridian to research, develop, manufacture, market and sell an antibody product candidate in China. The Company has concluded that Viridian is a related party because although Fairmount Funds Management LLC owns less than 10 % of shares of the Company’s outstanding common stock, they have a seat on the Board and are also a 10% or greater stockholder of Viridian and have two seats on Viridian’s board of directors. As initial consideration for this license, the Company issued 38,707 shares of its common stock to Viridian during the year ended December 31, 2020. As of December 31, 2025, Viridian held 0.1 % of shares of the Company’s outstanding common stock. Zai Lab (Hong Kong) Limited The Company has granted a sublicense to Zai to develop, manufacture and commercialize ZB001 and related programs in greater China. The Company has concluded that Zai is a related party, as the Company’s CEO and Chairman is a member of Zai’s board of directors. 191 Table of Contents InnoCare Pharma Inc. The Company has obtained the exclusive rights from InnoCare to develop, manufacture and commercialize three product candidates pursuant to the InnoCare License Agreement. Though InnoCare does not hold any direct controlling interest in the Company, the Company has concluded that InnoCare is a related party, due to the 5,000,000 shares of common stock issued and the 2,000,000 shares of common stock to be issued pursuant to the InnoCare License Agreement. As of December 31, 2025, InnoCare held less than 10 % of shares of the Company’s outstanding common stock. For additional information on these arrangements, please see Note 7, License and Collaboration Revenue and Note 8, License Agreements to these consolidated financial statements. ​ 17. Segment Information ​ The Company manages its operations on a consolidated basis as a single reportable segment focused on the research, development and commercialization of transformative immunology-based therapies. The accounting policies of the single reportable segment are identical to those described in Note 2, Summary of Significant Accounting Policies . When evaluating the Company’s financial performance, the Company’s CODM, its Chief Executive Officer regularly reviews consolidated net loss, total expense and direct expenses by program and compared to budget. The CODM allocates resources based on the Company’s available cash resources, and forecasted expenditures on a consolidated basis, as well as an assessment of the probability of success of its research and development activities on a program basis. Segment asset information regularly provided to the CODM is consistent with that reported on the consolidated balance sheets with particular emphasis on the Company’s available liquidity, including its cash, cash equivalents and investment balances. Revenue is attributed to the applicable subsidiaries based on the ownership of the license that was sold. During the years ended December 31, 2025 and 2024, $ 10.0 million and $ 5.0 million was recognized as revenue, respectively, and was attributed to Zenas HK. 192 Table of Contents The following table presents certain financial data for the Company’s reportable segments for the years ended December 31, 2025 and 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2025 ​ ​ 2024 ​ Revenue ​ $ 10,000 ​ $ 5,000 ​ Less: ​ ​ ​ ​ ​ ​ ​ Direct research and development expenses: 1 ​ ​ ​ ​ ​ ​ ​ Obexelimab ​ ​ 104,605 ​ ​ 94,563 ​ Orelabrutinib ​ ​ 7,208 ​ ​ — ​ Other programs (ZB002, ZB004, ZB021 & ZB022) ​ ​ 3,677 ​ ​ 2,115 ​ Partnered regional programs (ZB001 & ZB005) ​ ​ 159 ​ ​ 6,737 ​ Unallocated research and development 2 ​ ​ 43,576 ​ ​ 31,658 ​ General and administrative 3 ​ ​ 35,813 ​ ​ 22,995 ​ Acquired in-process research and development 4 ​ ​ 171,672 ​ ​ — ​ Stock-based compensation ​ ​ 26,347 ​ ​ 10,821 ​ Other segment items 5 ​ ​ ( 5,320 ) ​ ​ ( 6,901 ) ​ Segment net loss ​ $ ( 377,737 ) ​ $ ( 156,988 ) ​ 1 Direct research and development expenses primarily consist of direct costs incurred to specific program research and development activities, including costs to conduct clinical trials and to manufacture clinical drug supply. 2 Unallocated research and development expenses primarily consist of indirect costs incurred in support of overall research and development activities and non-specific programs, including activities that benefit multiple programs, such as personnel costs for employees involved in research and development activities, excluding stock-based compensation, as well as contract services not allocated to specific programs. 3 General and administrative expenses primarily consist of professional fees, depreciation expense, facilities expenses as well as all other personnel costs, excluding stock-based compensation 4 Acquired in-process research and development expenses consist of an upfront payment and the respective fair values of equity consideration pursuant to the InnoCare License Agreement, for additional information see Note 8, License Agreements , to these consolidated financial statements 5 Other segment items consist of other income (expense), net and income tax provision (benefit). Other income (expense), net consists of interest income, interest expense related to the royalty obligation and realized and unrealized gains and losses on foreign currency transactions. ​ ​ 18. Subsequent Events ATM Program ​ Since January 1, 2026, the Company completed the sales of 2,827,723 shares of common stock under the 2025 ATM Program, with an average gross sales price of $ 26.07 per share, resulting in proceeds of $ 71.5 million, net of commissions. As of the issuance date of these financial statements, $ 96.8 million remained available under the 2025 ATM Program. Senior Secured Term Loan On March 14, 2026, the Company entered into a five-year senior secured term loan (the “Loan Agreement”) with Credit PLC (the “Collateral Agent”), BPCR Limited Partnership and BioPharma Credit Investments V (Master) LP, which are funds managed by Pharmakon Advisors, LP (“Pharmakon”). The Loan Agreement provides a term loan facility of up to an aggregate principal amount of $ 250.0 million, subject to the achievement of certain development and commercial milestones. The term loan consists of five tranches including the initial tranche of $ 75.0 million drawn upon the execution of the Loan Agreement, and up to an additional $ 175.0 million available as future tranches. ​ The Term Loan bears interest at a rate of the 3-month secured overnight financing rate (subject to a 3.25 % floor) plus 5.75 % payable quarterly in arrears; provided that the Company may elect for 100 % of the interest for the first 24 months following the first tranche funding date to be paid-in-kind without an increase in the interest rate. ​ The Company is required pay a funding fee equal to 1.00 % or 2.00 % depending on the tranche being drawn. 193 Table of Contents ​ The Company may elect to prepay the Term Loans in whole or, subject to certain conditions, in part prior to maturity with such prepayments being subject to certain prepayment, make-whole and exit fees. The Term Loans are subject to certain mandatory prepayments, including a repayment in full of all term loans in four equal payments commencing on September 30, 2028 to the extent certain conditions are not met on or prior to June 30, 2028. ​ The Loan Agreement contains customary affirmative and restrictive covenants and representations and warranties. The Company is bound by certain affirmative covenants setting forth actions that are required during the term of the Loan Agreement, including a minimum liquidity covenant of $ 50.0 million prior to FDA approval of obexelimab. ​ The Company’s obligations under the Loan Agreement are secured by substantially all of its assets, including its intellectual property. ​ ​ Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure None. ​