JACOBIO-B - VOLUNTARY ANNOUNCEMENT

JACOBIO RECEIVED $100 MILLION UPFRONT PAYMENT FROM ASTRAZENECA UNDER THE LICENSE AND COOPERATION AGREEMENT FOR THE PAN-KRAS INHIBITOR JAB-23E73

JACOBIO PHARMACEUTICALS GROUP CO., LTD.

加科思藥業集團有限公司

(Incorporated in the Cayman Islands with limited liability)

(Stock code: 1167)

VOLUNTARY ANNOUNCEMENT

JACOBIO RECEIVED $100 MILLION UPFRONT PAYMENT FROM

ASTRAZENECA UNDER THE LICENSE AND COOPERATION AGREEMENT

FOR THE PAN-KRAS INHIBITOR JAB-23E73.

This announcement is made by JACOBIO PHARMACEUTICALS GROUP CO., LTD. (the "Company" or "Jacobio", together with its subsidiaries, the "Group") on a voluntary basis to inform the shareholders of the Company and potential investors about the latest business advancement of the Group.

Reference is made to the announcement of the Company dated December 21, 2025 in relation to the entering into the licence and collaboration agreement (the "Licence and Collaboration Agreement") by Jacobio Pharmaceuticals Co., Ltd.（北京加科思新藥研發有限公司）("Beijing Jacobio") and AstraZeneca AB ("AstraZeneca"). Unless otherwise defined, capitalised terms used herein shall have the same meanings as defined in the Announcement.

The board (the "Board") of directors (the "Director(s)") of the Company is pleased to announce that Beijing Jacobio, an indirect non-wholly owned subsidiary of the Company has received the upfront payment of US$100.0 million from AstraZeneca pursuant to the Licence and Collaboration Agreement. The receipt of such upfront payment will further bolster the Group's cash reserves and facilitate the advancement of the Group's subsequent pipeline development of innovative oncology therapies.

About Jacobio

Jacobio is committed to developing and providing new and innovative products and solutions to improve patients' health. Our pipeline revolves around targeted oncology and tumor immunotherapy with pipelines in KRAS, Sting, P53 and MYC pathways. We aim for our key projects to be among the top three in the world. Our vision is to become a global leader recognized for our impact in drug R&D together with our partners. Jacobio has R&D centers in Beijing, Shanghai and Boston with our Induced Allosteric Drug Discovery Platform (IADDP) and our immunostimulatory antibody-drug conjugate (iADC) Platform.

By Order of the Board

JACOBIO PHARMACEUTICALS GROUP CO., LTD. Yinxiang WANG

Chairman

Hong Kong, March 30, 2026