GSK walks away from remaining IDEAYA programs, formally ending partnership

GSK has elected to terminate its Collaboration, Option and License Agreement with IDEAYA Biosciences, formally ending their synthetic lethality partnership after about five years.1 3

The termination notice was communicated on December 4, 2025, and disclosed by IDEAYA in securities filings and subsequent news reports.1 3 4

The original alliance, focused on synthetic lethality–based oncology drugs, covered multiple DNA damage repair targets, including Werner helicase (WRN) and Pol Theta (POLQ) clinical programs.2 3 5

Following termination, GSK will transfer the Werner helicase and Pol Theta clinical programs back to IDEAYA, including certain trial responsibilities and associated data.2

IDEAYA regains full global rights to the affected programs and plans to continue developing its synthetic lethality pipeline independently or with new partners.2 3 6

The collaboration was initially signed as a multi-target, multi-year R&D and option deal under which GSK had rights to opt in and co-develop/market IDEAYA-discovered programs in oncology.3 5

GSK’s decision is part of a broader portfolio reprioritization and strategy shift, as the company concentrates resources on other oncology and pipeline priorities.4 5 6

Financially, IDEAYA loses potential future milestone and royalty streams from the GSK deal but avoids further cost-sharing obligations and retains upside from any successful in-house or re-partnered programs.3 4 6

Operationally, IDEAYA must now assume or transition clinical trial operations and manufacturing responsibilities that had been shared with or managed by GSK for the returning assets.2 6

News and market commentary indicate investor focus on whether IDEAYA can secure new partners or financing to advance WRN, POLQ, and other synthetic lethality assets at similar or better economics than the prior GSK arrangement.2 3 6