GSK announced it has signed a definitive agreement to acquire RAPT Therapeutics, a California-based clinical-stage biotech, in a transaction that will add ozureprubart, a long-acting anti-immunoglobulin E (IgE) monoclonal antibody, to GSK’s Respiratory, Immunology & Inflammation pipeline.
The centerpiece asset, ozureprubart, is in Phase IIb development as a prophylactic therapy intended to prevent reactions to food allergens. GSK said IgE is a clinically validated target and cited estimates that roughly 94% of severe food allergies are IgE-mediated. The companies framed ozureprubart as potentially “best-in-class,” highlighting a dosing profile that could allow administration every 12 weeks, compared with current anti-IgE food allergy treatments, which typically require injections every 2 to 4 weeks.
GSK said less frequent dosing could reduce treatment burden, particularly because many food allergy patients are children, and could help improve adherence and outcomes. The company also said ozureprubart could expand access for patients who are currently ineligible for existing therapy, estimating that roughly a quarter of patients fall into that category.
RAPT’s Phase IIb prestIgE trial evaluating ozureprubart as monotherapy is expected to report data in 2027, according to the announcement. GSK said Phase III studies are planned to include both adult and pediatric populations at risk. The company also cited U.S. prevalence estimates of more than 17 million people diagnosed with food allergies and over 1.3 million experiencing severe reactions, with a significant portion of severe cases occurring in children and adolescents, and millions of annual hospital and emergency visits tied to allergic events.
Under the terms of the agreement, GSK will pay $58.00 per share in cash, implying an aggregate equity value of approximately $2.2 billion. Net of cash acquired, GSK estimated its upfront investment at about $1.9 billion. GSK said it will obtain global rights to the ozureprubart program, excluding mainland China, Macau, Taiwan, and Hong Kong, and will assume responsibility for certain success-based milestone and royalty obligations owed to RAPT’s partner, Shanghai Jeyou Pharmaceutical.
Support: Evercore is serving as GSK’s exclusive financial advisor, with A&O Shearman as legal counsel. RAPT is being advised by J.P. Morgan Securities, with Cooley as legal counsel.
KEY QUOTES:
“The addition of ozureprubart brings another promising new, potential best-in-class treatment to GSK’s pipeline. Food allergies cause severe health impacts to patients with existing treatment requiring injections as frequently as every 2 weeks. Ozureprubart offers the opportunity to bring sustained protection to patients with dosing every 12 weeks, and is consistent with our approach to acquire assets that address validated targets and where there is clear unmet medical need.”
Tony Wood, Chief Scientific Officer, GSK
“We are excited to enter into this agreement with GSK, which offers an attractive path forward for our programs, particularly the opportunity we envision for ozureprubart in food allergy. This transaction has the potential to provide access to the global development and commercialisation capabilities, resources and infrastructure that GSK has to offer and ultimately bring added value to our pipeline, patients and stockholders.”
Brian Wong, President & Chief Executive Officer, RAPT Therapeutics
