GSK entered into a definitive agreement to acquire RAPT Therapeutics, including RAPT’s long-acting anti-immunoglobulin E (IgE) monoclonal antibody,ozureprubart, currently in phase IIb clinical development for prophylactic protection against food allergens.¹

As of January 20, 2026, IgE is the only approved systemic therapy that has displayed the ability to protect patients from both a harmful allergic and inflammatory immune response.¹ IgE is a clinically validated target with around 94% of severe food allergies being caused by IgE-mediated reactions.¹

“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 commercialization capabilities, resources and infrastructure that GSK has to offer and ultimately bring added value to our pipeline, patients and stockholders,” said Brian Wong, president & chief executive officer, RAPT Therapeutics.

Why was ozureprubart included in the acquisition?

Tony Wood, chief scientific officer, GSK discussed the importance of including ozureprubart in the acquisition, saying, “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.”

Current anti-IgE standard of care treatments for food allergies involves multiple injections ranging every two to four weeks and can result in becoming a burden for patients since most are children.¹

In the U.S., upwards of 17 million people are diagnosed with food allergies, with over 1.3 million people suffering severe reactions, resulting in more than 3 million patient visits each year to both hospitals and emergency care centers.¹

Additionally, GSK states that ozureprubart’s clinical profile holds the potential to offer a reduced frequency of dosing, reducing the frequency to every 12 weeks instead of the typical two to four, and supporting improved compliance and patient outcomes.¹ Ozureprubart also provides a new option to an estimated 25% of patients currently ineligible for existing therapy and complements GSK’s extensive commercial footprint and prescriber base in allergy.

GSK is expecting data from the prestIgE phase IIb trial assessing the use of ozureprubart as monotherapy in 2027, with phase III trials set to be focused on both at-risk adult and pediatric populations.¹

What are the financial implications of the acquisition?

Per the terms of the definitive agreement, GSK is set to pay RAPT Therapeutics shareholders $58 per share at closing, resulting in a total value of $2.2 billion and an estimated upfront investment of $1.9 billion.¹ The transaction is expected to close in the first quarter of 2026 and will grant GSK global rights to the ozureprubart program except in mainland China, Macau, Taiwan and Hong Kong.¹

Sources

1. GSK enters agreement to acquire RAPT Therapeutics GSK January 20, 2026 https://www.gsk.com/en-gb/media/press-releases/gsk-enters-agreement-to-acquire-rapt-therapeutics/