GlaxoSmithKline announced that it has agreed to acquire U.S.-based RAPT Therapeutics in a deal valued at $2.2 billion. Under the terms, GSK will pay RAPT shareholders $58 per share, representing a total upfront cash investment of $1.9 billion. The acquisition is intended to bolster GSK’s immunology portfolio, with RAPT’s lead asset—a selective SIK2 inhibitor for food allergy—expected to enter Phase II clinical trials by mid-2026. GSK forecasts peak annual sales of up to $1.5 billion for the program, positioning it as a potential blockbuster addition to its respiratory and immunology franchise. The deal remains subject to customary regulatory approvals and is targeted to close in the third quarter of 2026.

Tesaro, a wholly owned oncology subsidiary of GSK, has entered into an exclusive global license agreement with South Korea–based Alteogen for the development and commercialization of a subcutaneous formulation of dostarlimab using Alteogen’s Hybrozyme™ technology (ALT-B4). GSK will make an upfront payment of $20 million and is committed to potential milestone payments totaling up to $265 million upon achievement of agreed development, regulatory and sales targets. In addition, GSK will pay tiered royalties on future product sales. The subcutaneous formulation aims to improve patient convenience and expand market adoption of dostarlimab, which generated over $1 billion in global revenues in 2025 as an intravenous PD-1 inhibitor in endometrial and other solid tumors.