Gilead Sciences, a research-based biopharmaceutical company, agreed to acquire a 49.9% stake in Pionyr Immunotherapeutics, a developer of cancer immunotherapies. The transaction is subject to customary closing conditions and is expected to close shortly. Pionyr’s shareholders will receive $275m upon closing. Gilead will receive 49.9% of the common stock of Pionyr and an exclusive option to purchase the remaining equity. Gilead may exercise its exclusive option upon completion of Phase 1b studies for PY314 and PY159, or at an earlier time if Gilead chooses to do so, for a $315m option exercise fee and up to $1.15 billion in potential future milestone payments. In addition, Gilead will provide Pionyr with additional funding for the PY314 and PY159 clinical programs, as well as ongoing research and development programs “Pionyr is pursuing promising, novel biology in the field of immuno-oncology. The agreement represents important progress as we continue to build out Gilead's presence in immuno-oncology with innovative and complementary approaches. We look forward to seeing the programs advance with the goal of developing new therapies that will improve the treatment of cancer,” Daniel O’Day, Gilead Sciences Chairman and Chief Executive Officer.