GSK’s $2.2 billion acquisition of RAPT Therapeutics signals bold move into immunology and food allergy market

GSK will acquire US biopharmaceutical company RAPT Therapeutics for $58.00 a share, in a transaction valuing the immunology specialist at about $2.2 billion and marking one of the first major pharma deals of 2026.

According to Pharmaceutical Technology, the deal gives GSK global commercial rights to ozureprubart, RAPT’s long‑acting anti‑immunoglobulin E (IgE) monoclonal antibody being developed for the prevention of food allergy, excluding China, Taiwan, Macau and Hong Kong. The candidate is in a Phase IIb trial, prestIgE (NCT07220811), enrolling in the United States, Australia and Canada, with a data readout expected in 2027. RAPT said the transaction is subject to customary closing conditions and is expected to complete in the first quarter of 2026.

GSK is paying a substantial premium to RAPT’s pre‑deal share price: the offer price compares with RAPT’s closing price of $35.10 on 16 January, and trading jumped toward the $58 level after the agreement was announced, industry reports show. RAPT’s own announcement confirmed the $58.00 per‑share cash consideration and the estimated $2.2 billion valuation.

Company and analyst commentary has highlighted ozureprubart’s once‑every‑12‑weeks dosing as a potential differentiator versus marketed anti‑IgE therapies that require injections every two to four weeks. According to PharmExec and Investing, GSK has described the asset as having “best‑in‑class” potential in the food allergy space if regulatory approval is achieved.

The acquisition sits within a broader GSK strategy to strengthen its immunology and respiratory pipeline. Pharmaceutical Technology noted GSK last year agreed a deal worth up to $12 billion with Hengrui Pharma covering immunology, respiratory and oncology assets and signed a five‑year, £50 million research agreement with the University of Cambridge to pursue treatments for diseases driven by immune dysfunction.

The transaction also arrives as major drugmakers prepare for a pronounced patent cliff. GlobalData figures cited by Pharmaceutical Technology estimate that losses of exclusivity across the top companies could translate into roughly $230 billion of missing sales in the US between 2025 and 2030, a backdrop that has driven aggressive dealmaking and increased focus on validated targets and faster paths to market. Speaking at the 44th Annual 2026 J.P. Morgan Healthcare Conference, GSK’s chief scientific officer, Tony Wood, emphasised the company’s intention to lean on AI‑driven early‑stage R&D to replenish the pipeline and offset expiries, according to coverage of his remarks.

Legal advisers to the deal have been publicised: A&O Shearman said it advised GSK on the acquisition. RAPT’s announcement and several industry outlets, including Livemint and Investing, reiterated that closing remains subject to customary conditions.

Industry commentary noted the timing of the deal: the J.P. Morgan conference produced fewer blockbuster announcements than in prior years, yet analysts remain optimistic that 2026 will see sustained M&A activity as companies seek near‑term, late‑stage assets to shore up future revenues, according to Pharmaceutical Technology.

GSK’s acquisition of RAPT advances its foothold in immunology and food allergy at a moment when less frequent dosing regimens and validated biological targets are seen as commercially and clinically attractive. The transaction’s commercial and regulatory success will hinge on the Phase IIb readout expected in 2027 and subsequent clinical development decisions.