Nature of Business	12 Months Ended
Dec. 31, 2025
Nature of Business
Nature of Business	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 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.

Nature of Business

12 Months Ended

Dec. 31, 2025

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

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.