Gilead Sciences to pay $300 million for nearly half of Tizona, has option to buy the rest for $1.25 billion

Gilead Sciences Inc. GILD, -0.91% announced Tuesday a deal to buy a 49.9% stake in privately held cancer treatment developer Tizona Therapeutics Inc. for $300 million. Gilead also received an option to buy the remainder of Tizona for up to an additional $1.25 billion, including potential future milestone payments.