GSK Finalizes $2.2 Billion Acquisition of RAPT Therapeutics, Targeting Food Allergy Market

GSK (NYSE: GSK) has announced its acquisition of RAPT Therapeutics for $2.2 billion, marking the first major strategic move under newly appointed CEO Luke Miels. Notably, the transaction positions GSK to enter the increasingly competitive food allergy treatment market, anchored by RAPT’s investigational antibody, ozureprubart.

Acquisition and Financial Details

Under the terms of the agreement, GSK will acquire all outstanding shares of RAPT Therapeutics for $58 per share in cash. After factoring in RAPT’s existing cash balance, GSK’s net upfront investment is expected to be approximately $1.9 billion. Following the announcement, RAPT’s stock rose sharply in pre-market trading, increasing 63.8% from its prior close of $35.10.

Strategic Asset: Ozureprubart

At the core of the acquisition is ozureprubart, a long-acting anti-IgE monoclonal antibody being developed as a prophylactic therapy for food allergies. Importantly, IgE is a well-validated target, implicated in roughly 94% of severe food allergy reactions. Moreover, ozureprubart’s proposed once-every-12-weeks dosing schedule differentiates it from currently available anti-IgE therapies, which typically require injections every two to four weeks. As a result, the extended dosing interval could meaningfully enhance patient adherence and clinical outcomes.

The Phase IIb prestIgE trial in food allergy patients was initiated in October 2024, with data expected in 2027. In parallel, ozureprubart is being evaluated in chronic spontaneous urticaria, where topline data released in October 2025 demonstrated a statistically significant reduction in urticaria activity using a 12-week dosing regimen.

Competitive Landscape and Market Implications

With this asset, GSK is poised to compete directly with Roche’s established IgE inhibitor, Xolair. Earlier, in February 2024, Xolair became the first FDA-approved therapy to reduce allergic reactions, including anaphylaxis, following food exposure. Subsequently, Roche strengthened its position with positive Phase III OUtMATCH trial results. For the first nine months of 2025, Xolair generated approximately $2.82 billion in revenue across multiple indications.

Overall, the acquisition underscores a clear strategic direction for GSK under Luke Miels, who formally assumed the CEO role on January 1, 2026. By securing a differentiated, clinical-stage asset, GSK is laying the foundation for a new franchise within the high-value allergy and immunology market.