GSK has announced the acquisition of RAPT Therapeutics for $2.2 billion, marking the first major move by new CEO Luke Miels. The agreement will see GSK purchase all outstanding shares of RAPT at $58 per share in cash. After accounting for cash included in the transaction, GSK’s net upfront investment stands at $1.9 billion.
Following the announcement, RAPT’s stock price rose significantly in pre-market trading, reflecting a 63.8% increase from its previous close.
The main asset driving this acquisition is ozureprubart, an investigational long-acting anti-IgE monoclonal antibody being developed as a preventive treatment for food allergies. According to GSK, “Around 94% of severe food allergies are linked to IgE reactions,” and targeting IgE has been shown to provide protection against allergic and inflammatory responses.
Ozureprubart is designed for dosing once every 12 weeks, which GSK states supports “improved compliance and patient outcomes” compared to other anti-IgE therapies that require more frequent injections.
RAPT began a Phase IIb study called prestIgE last October to evaluate ozureprubart in patients with food allergies. Results from this trial are expected in 2027. In addition to food allergies, ozureprubart is also being studied for chronic spontaneous urticaria; topline data released in October 2025 indicated that dosing every 12 weeks led to significant reductions in urticaria activity between weeks eight and sixteen.
With this acquisition, GSK aims to compete with Roche’s Xolair (omalizumab), which became the first FDA-approved therapy for reducing allergic reactions—including anaphylaxis—caused by food in February 2024. In March of that year, Roche published results from its Phase III OUtMATCH trial showing Xolair provided greater tolerance to peanuts and two other allergens compared with oral immunotherapy.
Xolair generated nearly 2.23 billion Swiss francs (about $2.82 billion) during the first nine months of 2025 across multiple indications such as allergic asthma and chronic hives.
Luke Miels assumed his role as CEO on January 1 after being appointed last September. He succeeds Emma Walmsley, who served as CEO since 2017.
