Gilead Sciences, a research-based biopharmaceutical company, agreed to acquire a 49.9% stake in Tizona Therapeutics, a privately held company developing cancer immunotherapies, for $300m. Gilead will also receive an exclusive option to acquire the remainder of Tizona for up to an additional $1.25bn, including an option exercise fee and potential future milestone payments. "Tizona is pursuing first-in-class cancer immunotherapies that could make an important difference in oncology by helping patients who don’t respond to current checkpoint inhibitors. This agreement with Tizona adds to the significant progress we’ve made in the first half of this year in building out a strong and diverse immuno-oncology pipeline. We now have multiple opportunities to develop novel therapies that will improve the treatment of cancer," Daniel O’Day, Gilead Sciences Chairman and CEO.