Recurium IP Holdings, LLC Agreement	9 Months Ended
Sep. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recurium IP Holdings, LLC Agreement	Recurium IP Holdings, LLC Agreement Pursuant to a license agreement (“the Recurium Agreement”) entered into in December 2014 between the Company’s wholly owned subsidiary, Zeno Pharmaceuticals, Inc., and Recurium IP Holdings, LLC (“Recurium IP”), which was subsequently amended, Recurium IP provided Zeno Pharmaceuticals, Inc. with an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for providing pain relief. Following a corporate restructuring, our wholly owned subsidiary, Zeno Management, Inc. (“ZMI”) became the Zentalis contracting party to the Recurium Agreement. The intellectual property rights exclusively licensed by ZMI under the Recurium Agreement include certain intellectual property covering azenosertib. Under the Recurium Agreement, ZMI has the right to sublicense its rights, subject to certain conditions. ZMI is required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a compound modulating one of ten specific biological targets and to execute certain development activities. Under the terms of the Recurium Agreement, ZMI is obligated to make development and regulatory milestone payments, pay royalties on net sales, and make certain sublicensing payments with respect to products that comprise or contain a compound modulating one of ten specific biological targets, including azenosertib. ZMI is obligated to make development and regulatory milestone payments for each such licensed product of up to $44.5 million, which covers the first two indications for which such licensed product receives regulatory approval. During the nine months ended September 30, 2026, the Company incurred and paid a $7.0 million milestone payment to Recurium IP as a result of the commencement of our Phase 3 ASPENOVA clinical trial. The payment has been recorded as research and development expense in the condensed consolidated statement of operations. In the event that a licensed product receives regulatory approval in any additional indications beyond the first two, ZMI would be obligated to pay an additional one-time milestone payment for each such approval. In addition, ZMI is obligated to make milestone payments of up to $150 thousand for certain licensed products used in animals. ZMI is also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if ZMI chooses to sublicense or assign to any third parties its rights under certain patents exclusively in-licensed under the Recurium Agreement, ZMI must pay to Recurium IP 20% of certain sublicensing income received in connection with such transaction. The Recurium Agreement will expire on the later of December 21, 2032 and, on a country-by-country basis, on the date of expiration of the last-to-expire royalty term for all licensed products in such country, unless earlier terminated by either party for cause or a bankruptcy event.

Pursuant to a license agreement (“the Recurium Agreement”) entered into in December 2014 between the Company’s wholly owned subsidiary, Zeno Pharmaceuticals, Inc., and Recurium IP Holdings, LLC (“Recurium IP”), which was subsequently amended, Recurium IP provided Zeno Pharmaceuticals, Inc. with an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for providing pain relief. Following a corporate restructuring, our wholly owned subsidiary, Zeno Management, Inc. (“ZMI”) became the Zentalis contracting party to the Recurium Agreement.

The intellectual property rights exclusively licensed by ZMI under the Recurium Agreement include certain intellectual property covering azenosertib. Under the Recurium Agreement, ZMI has the right to sublicense its rights, subject to certain conditions. ZMI is required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a compound modulating one of ten specific biological targets and to execute certain development activities.

Under the terms of the Recurium Agreement, ZMI is obligated to make development and regulatory milestone payments, pay royalties on net sales, and make certain sublicensing payments with respect to products that comprise or contain a compound modulating one of ten specific biological targets, including azenosertib. ZMI is obligated to make development and regulatory milestone payments for each such licensed product of up to $44.5 million, which covers the first two indications for which such licensed product receives regulatory approval. During the nine months ended September 30, 2026, the Company incurred and paid a $7.0 million milestone payment to Recurium IP as a result of the commencement of our Phase 3 ASPENOVA clinical trial. The payment has been recorded as research and development expense in the condensed consolidated statement of operations. In the event that a licensed product receives regulatory approval in any additional indications beyond the first two, ZMI would be obligated to pay an additional one-time milestone payment for each such approval. In addition, ZMI is obligated to make milestone payments of up to $150 thousand for certain licensed products used in animals. ZMI is also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if ZMI chooses to sublicense or assign to any third parties its rights under certain patents exclusively in-licensed under the Recurium Agreement, ZMI must pay to Recurium IP 20% of certain sublicensing income received in connection with such transaction.