GSK entered into a definitive agreement to acquire RAPT Therapeutics, a clinical-stage biopharmaceutical focused on immunology and inflammation, in a deal valued at approximately USD 2.2 billion in cash. The agreement targets RAPT’s Phase 2b-stage ozureprubart, under development as a food allergy prophylactic as well as immunology pipeline. GSK expects transaction closure in Q1 2026.
Under the deal terms, GSK will pay USD 58 per share in cash for RAPT’s outstanding stock, representing USD 2.2 billion, or USD 1.9 billion taking into account RAPT’s existing cash holdings.
Ozureprubart is a long-acting anti-immunoglobulin E (IgE) monoclonal antibody in Phase IIb development for prophylactic protection against food allergens. GSK acquires rights to the drug candidate globally excluding mainland China, Macau, Taiwan, and Hong Kong. This reflects the fact that ozureprubart was originally developed by Shanghai Jeyou Pharmaceutical Co., Ltd, a subsidiary of Jiangxi Jemincare Group, and licensed to RAPT in October 2025.
Ozureprubart is designed to bind to free and cell-bound IgE, preventing IgE from interacting with its high-affinity receptor (FcεRI) on mast cells and basophils, thereby inhibiting the allergic cascade.
GSK is aiming to muscle in on a market currently dominated by Novartis/Genentech’s omalizumab (Xolair), which became the first and only anti-IgE biologic for food allergy in 2024 and represents the current standard-of-care. Ozureprubart is designed to offer less frequent dosing (every 12 weeks) compared with omalizumab’s injections every 2 to 4 weeks.