GSK announces $2.2 billion acquisition of RAPT Therapeutics for inflammatory disease therapies

GSK Plc announced on January 20, 2026, that it has entered into a definitive agreement to acquire RAPT Therapeutics, a California-based clinical-stage biopharmaceutical company, in a deal valued at $2.2 billion. The acquisition targets RAPT's focus on developing novel therapies for patients with inflammatory and immunologic diseases.

Deal Structure and Financial Terms

The acquisition involves significant financial commitments and strategic positioning for GSK's pipeline expansion.

GSK's subsidiary will issue a tender offer to acquire all outstanding shares of RAPT common stock for $58.00 per share in cash. The transaction is expected to close by the end of the first quarter of calendar year 2026.

Strategic Asset Acquisition

The deal provides GSK with valuable intellectual property and development programmes in the inflammatory disease space. GSK will acquire global rights to RAPT Therapeutics' ozureprubart programme, excluding rights in Mainland China, Macau, Taiwan and Hong Kong.

Additionally, GSK will assume responsibility for success-based milestone and royalty payments for ozureprubart owed to RAPT's partner, Shanghai Jeyou Pharmaceutical Co., Ltd. This arrangement ensures continuity of existing partnerships while expanding GSK's global reach.

Clinical Significance and Market Opportunity

Tony Wood, Chief Scientific Officer of GSK, highlighted the strategic value of the acquisition: "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."

The acquisition aligns with GSK's strategy to acquire assets that address validated targets where clear unmet medical need exists.

Advisory Teams and Market Response

The transaction involves prominent financial and legal advisors on both sides:

Stock Performance Impact

The acquisition announcement generated significant market reactions across both companies' shares.

GSK shares have delivered strong long-term performance with over 28% returns in the last five years and over 32% returns in the last one-year period. RAPT Therapeutics shares have shown volatility, rising 265% in the last one-year period but declining over 79% in the last five years.