License Agreements	6 Months Ended
Jun. 30, 2026
Asset Acquisition [Abstract]
License Agreements	License Agreements 2023 Lilly License On April 26, 2023, ZB17 entered into a license agreement with Lilly (the “2023 Lilly License”) for an exclusive license to develop, manufacture and commercialize tibulizumab. The Company is obligated to make payments to Lilly (a) for 4 development milestone payments up to an aggregate of $155.0 million, and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from tibulizumab; and (b) over a multi-year period (twelve years, or upon the later expiration of regulatory exclusivity of tibulizumab in a country) for an annual earned royalty at a marginal royalty rate in the mid-single digits to low-double digits, with increasing royalty percentage rates depending on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of years (collectively, the “2023 Lilly Contingent Payments”). As of June 30, 2026, none of the 2023 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due. 2022 Lilly License On December 8, 2022, the Company’s consolidated subsidiary, Z33, entered into a license agreement with Lilly pursuant to which Lilly granted Z33 an exclusive (even as to Lilly) license to develop, manufacture, and commercialize torudokimab. The Company is obligated to make payments to Lilly for (a) 10 commercial, development and regulatory milestone payments up to an aggregate of $155.0 million and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from the licensed compound, if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single to low-double digits, with increasing royalty percentage rates based on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of the year, if any year (collectively, the “2022 Lilly Contingent Payments”). The Company will account for these contingent milestone payments when they become due. As of June 30, 2026, none of the 2022 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due. Pfizer Agreement On March 22, 2022, the Company entered into a license agreement and a Series A-1 Subscription and Shareholder’s Agreement (collectively, the “Pfizer Agreement”) with Pfizer. Under the Pfizer Agreement, the Company acquired a license for crebankitug. The Company is obligated to make payments to Pfizer for (a) 11 remaining future development and regulatory milestone payments aggregating up to $69.0 million and sales milestone payments up to an aggregate of $525.0 million based on respective thresholds of net sales of products (developed from the licensed compound) (the “Products”), if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single digits to low double digits (less than 20%), based on thresholds of net sales of the Company’s Products, if any (collectively, the “Pfizer Contingent Payments”). As of June 30, 2026, none of the Pfizer Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due. Lonza License In July 2022, the Company entered into a license agreement (the “Lonza License”) with Lonza Sales AG (“Lonza”) for a worldwide non-exclusive license for Lonza’s gene expression system in exchange for varying considerations depending on a number of factors such as whether the Company enters further into manufacturing agreements with Lonza or with a third party, and whether the Company enters into sublicense agreements with third parties (including up to middle six-figure annual payments per sublicense upon commencement of a sublicense, as well as royalties of up to low-single digit percentages of net sales of certain products over a commercially standard double-digit multi-year term). The Lonza License will remain in effect until terminated. The Company is free to terminate the Lonza License at any time upon 60 days’ notice, with or without cause. Lonza may terminate the Lonza License for cause upon a breach by the Company or for other commercially standard reasons. Pursuant to the terms of the Lonza License, the Company has a license fee of $0.4 million due to Lonza annually in the fourth quarter as a result of manufacturing drug substance with a third party other than Lonza since 2023. WuXi Biologics License In July 2023, the Company entered into a cell line license agreement (the “Cell Line License Agreement”) with WuXi Biologics and its Affiliates (“WuXi Biologics”) for certain of WuXi Biologics’s know-how, cell line, and biological materials to manufacture, have manufactured, use, sell and import certain products produced through the use of the cell line licensed by WuXi Biologics under the Cell Line License Agreement (the “WuXi Biologics Licensed Products”). If the Company manufactures all of its commercial supplies of bulk drug product for WuXi Biologics Licensed Products with a manufacturer other than WuXi Biologics or its affiliates, the Company is required to make royalty payments to WuXi Biologics in an amount equal to a fraction of a single digit percentage of global net sales of WuXi Biologics Licensed Products manufactured by a third-party manufacturer (the “Royalty”). If the Company manufactures part of its commercial supplies of the WuXi Biologics Licensed Products with WuXi Biologics or its affiliates, then the Royalty will be reduced accordingly on a pro rata basis. The Cell Line License Agreement will continue indefinitely unless terminated (a) by the Company upon three months’ prior written notice and its payment of all undisputed amounts due to WuXi Biologics through the effective date of termination, (b) by WuXi Biologics for a material breach by the Company that remains uncured for 30 days after written notice; or (c) by WuXi Biologics if the Company fails to make a payment and such failure continues for 30 days after receiving notice of such failure. As of June 30, 2026, there are no payments currently due under the Cell Line License Agreement. Athanor Letter Agreement On December 29, 2025, the Company entered into a letter agreement with Athanor Capital, an exempted company incorporated under the laws of the Cayman Islands with limited liability (“Athanor”) (the “Athanor Agreement”), pursuant to which the Company issued to Athanor 8,657,402 Ordinary Shares (the “Athanor Shares”). Athanor is also entitled to piggyback registration rights pursuant to which Athanor has the right to include Athanor Shares in certain registered offerings by the Company or if the Company proposes to file a registration statement under the Securities Act of 1933, as amended, with respect to the registration of equity securities, as set forth in the Athanor Agreement. In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay Athanor an upfront fee in an amount equal to $7.3 million within thirty days of execution of the Athanor Agreement and a one-time milestone payment in the amount of $25.0 million after the occurrence of the earliest of the following events: (a) the Company or ZB17 undergoes a Change of Control (as defined in the Athanor Agreement), (b) the consummation by the Company or ZB17 of a sale of assets resulting in net proceeds in excess of $500.0 million; or (c) First Indication Regulatory Approval (as defined in the Athanor Agreement). In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay an amount equal to 2% of Net Sales (as defined in the Athanor Agreement) for the Product (as defined in the Athanor Agreement) to the extent such Net Sales (collectively, the “Net Sales Payments”) are the subject of a royalty payment under the 2023 Lilly License. The upfront fee was paid as of December 31, 2025. The Athanor Agreement contains representations, warranties and covenants by the parties in addition to the terms described above and shall remain in effect on a country-by-country basis until the expiration of the obligation to pay the Net Sales Payments.

The Company is obligated to make payments to Lilly (a) for 4 development milestone payments up to an aggregate of $155.0 million, and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from tibulizumab; and (b) over a multi-year period (twelve years, or upon the later expiration of regulatory exclusivity of tibulizumab in a country) for an annual earned royalty at a marginal royalty rate in the mid-single digits to low-double digits, with increasing royalty percentage rates depending on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of years (collectively, the “2023 Lilly Contingent Payments”). As of June 30, 2026, none of the 2023 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due.

The Company is obligated to make payments to Lilly for (a) 10 commercial, development and regulatory milestone payments up to an aggregate of $155.0 million and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from the licensed compound, if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single to low-double digits, with increasing royalty percentage rates based on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of the year, if any year (collectively, the “2022 Lilly Contingent Payments”). The Company will account for these contingent milestone payments when they become due. As of June 30, 2026, none of the 2022 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due.

The Company is obligated to make payments to Pfizer for (a) 11 remaining future development and regulatory milestone payments aggregating up to $69.0 million and sales milestone payments up to an aggregate of $525.0 million based on respective thresholds of net sales of products (developed from the licensed compound) (the “Products”), if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single digits to low double digits (less than 20%), based on thresholds of net sales of the Company’s Products, if any (collectively, the “Pfizer Contingent Payments”). As of June 30, 2026, none of the Pfizer Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due.

In July 2022, the Company entered into a license agreement (the “Lonza License”) with Lonza Sales AG (“Lonza”) for a worldwide non-exclusive license for Lonza’s gene expression system in exchange for varying considerations depending on a number of factors such as whether the Company enters further into manufacturing agreements with Lonza or with a third party, and whether the Company enters into sublicense agreements with third parties (including up to middle six-figure annual payments per sublicense upon commencement of a sublicense, as well as royalties of up to low-single digit percentages of net sales of certain products over a commercially standard double-digit multi-year term). The Lonza License will remain in effect until terminated. The Company is free to terminate the Lonza License at any time upon 60 days’ notice, with or without cause. Lonza may terminate the Lonza License for cause upon a breach by the Company or for other commercially standard reasons.

In July 2023, the Company entered into a cell line license agreement (the “Cell Line License Agreement”) with WuXi Biologics and its Affiliates (“WuXi Biologics”) for certain of WuXi Biologics’s know-how, cell line, and biological materials to manufacture, have manufactured, use, sell and import certain products produced through the use of the cell line licensed by WuXi Biologics under the Cell Line License Agreement (the “WuXi Biologics Licensed Products”). If the Company manufactures all of its commercial supplies of bulk drug product for WuXi Biologics Licensed Products with a manufacturer other than WuXi Biologics or its affiliates, the Company is required to make royalty payments to WuXi Biologics in an amount equal to a fraction of a single digit percentage of global net sales of WuXi Biologics Licensed Products manufactured by a third-party manufacturer (the “Royalty”). If the Company manufactures part of its commercial supplies of the WuXi Biologics Licensed Products with WuXi Biologics or its affiliates, then the Royalty will be reduced accordingly on a pro rata basis. The Cell Line License Agreement will continue indefinitely unless terminated (a) by the Company upon three months’ prior written notice and its payment of all undisputed amounts due to WuXi Biologics through the effective date of termination, (b) by WuXi Biologics for a material breach by the Company that remains uncured for 30 days after written notice; or (c) by WuXi Biologics if the Company fails to make a payment and such failure continues for 30 days after receiving notice of such failure. As of June 30, 2026, there are no payments currently due under the Cell Line License Agreement.

On December 29, 2025, the Company entered into a letter agreement with Athanor Capital, an exempted company incorporated under the laws of the Cayman Islands with limited liability (“Athanor”) (the “Athanor Agreement”), pursuant to which the Company issued to Athanor 8,657,402 Ordinary Shares (the “Athanor Shares”). Athanor is also entitled to piggyback registration rights pursuant to which Athanor has the right to include Athanor Shares in certain registered offerings by the Company or if the Company proposes to file a registration statement under the Securities Act of 1933, as amended, with respect to the registration of equity securities, as set forth in the Athanor Agreement.

In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay Athanor an upfront fee in an amount equal to $7.3 million within thirty days of execution of the Athanor Agreement and a one-time milestone payment in the amount of $25.0 million after the occurrence of the earliest of the following events: (a) the Company or ZB17 undergoes a Change of Control (as defined in the Athanor Agreement), (b) the consummation by the Company or ZB17 of a sale of assets resulting in net proceeds in excess of $500.0 million; or (c) First Indication Regulatory Approval (as defined in the Athanor Agreement). In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay an amount equal to 2% of Net Sales (as defined in the Athanor Agreement) for the Product (as defined in the Athanor Agreement) to the extent such Net Sales (collectively, the “Net Sales Payments”) are the subject of a royalty payment under the 2023 Lilly License. The upfront fee was paid as of December 31, 2025.