UK biopharmaceutical company GSK plc (LSE/NYSE: GSK) on Tuesday announced a definitive agreement to acquire RAPT Therapeutics (NASDAQ:RAPT), a California-based clinical-stage biopharmaceutical company, in a transaction valued at approximately USD2.2bn in equity.

The acquisition includes ozureprubart, a long-acting anti-IgE monoclonal antibody in phase IIb development for prophylactic protection against food allergens, targeting a growing area of unmet medical need. Ozureprubart is designed to offer less frequent dosing, potentially every 12 weeks, compared with current anti-IgE therapies that require injections every two to four weeks, which may improve patient compliance and outcomes.

Food allergies pose significant health risks, with IgE-mediated reactions accounting for the majority of severe cases, and more than 17 million diagnosed patients in the United States alone. GSK expects phase IIb data from the prestIgE trial in 2027, with subsequent phase III studies planned in adult and paediatric populations.

Under the agreement, GSK will pay USD58.00 per share in cash, representing an estimated upfront investment of USD1.9bn net of cash acquired. The transaction grants GSK global rights to ozureprubart, excluding mainland China, Macau, Taiwan and Hong Kong, and is expected to close in the first quarter of 2026.