Gilead Sciences, Inc. announced today that for $275 million the company will acquire a 49.9 percent equity interest in Pionyr Immunotherapeutics Inc., a privately held company developing first-in-class cancer immunotherapies, and an exclusive option to purchase the remainder of Pionyr. Under the agreement, Pionyr’s shareholders may receive up to an additional $1.47 billion in option exercise fees and future milestone payments.

Pionyr’s Myeloid Tuning™ therapies have the potential to treat patients who currently do not benefit from checkpoint inhibitor therapies. PY314 and PY159 have demonstrated preclinical efficacy, suggesting potential in solid tumors in combination with established anti-PD(L)-1 agents. Pionyr plans to file investigational new drug (IND) applications with the U.S. Food and Drug Administration for both PY314 and PY159 in the third quarter of this year. Pending Phase 1b results from either candidate – or sooner if Gilead chooses – Gilead can exercise its exclusive option to acquire the remainder of Pionyr.

“Pionyr is pursuing promising, novel biology in the field of immuno-oncology,” said Daniel O’Day, Chairman and Chief Executive Officer, Gilead Sciences. “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.”

“This agreement underscores the value of our myeloid tuning platform and the potential of our pipeline of antibody therapeutics designed to turbocharge the immune system within the tumor microenvironment,” said Steven P. James, President and Chief Executive Officer, Pionyr. “PY314 and PY159 are first-in-class antibodies designed to remove or reprogram, respectively, the immune suppressive cells in the tumor microenvironment and thereby enhance anti-tumor immunity. We are grateful that Gilead has acknowledged the promise of this transformational approach to potentially benefit patients across a range of solid tumors.”