RAPT Therapeutics stock (NASDAQ: RAPT) surged 63.86% to $57.52 in morning trading after GSK announced plans to acquire the biotech company in an all-cash transaction.
The deal highlights GSK’s expanding focus on food allergy treatments, an area gaining increasing clinical relevance and commercial momentum.
Under the terms of the agreement, GSK will pay $58 per share in cash, valuing RAPT’s equity at approximately $2.2 billion. After accounting for RAPT’s existing cash balance, the net transaction value is estimated at about $1.9 billion.
Strengthening GSK’s Allergy Portfolio
The acquisition is driven primarily by RAPT’s food allergy research pipeline, led by ozureprubart, an investigational anti-IgE antibody that GSK identified as a core strategic asset.
Specifically, ozureprubart is being developed as a preventive treatment for multiple food allergies, including peanut, milk, egg, cashew, and walnut. Consequently, the breadth of these indications positions the therapy to address a substantial and diverse patient population.
Moreover, GSK believes the therapy could offer meaningful advantages over existing treatments such as Xolair, particularly in dosing convenience. Ozureprubart is designed for administration every eight to twelve weeks, compared with Xolair’s typical two- to four-week dosing schedule.
Beyond convenience, GSK highlighted that ozureprubart may be appropriate for patients with elevated IgE levels or higher body weight. These populations, the company noted, are frequently ineligible for Xolair treatment under current guidelines.
The company also emphasized biological differences between the therapies. Ozureprubart reportedly binds IgE with four times greater affinity than Xolair and is capable of removing IgE already bound to immune cells.
Addressing a Large Unmet Need
These potential benefits are notable given the scale of the food allergy market. Company data indicate that more than 17 million people in the United States have diagnosed food allergies, including approximately six million children.
Additionally, roughly 40% of patients are allergic to multiple foods, which significantly increases daily risk exposure. Severity remains a major concern as well, with about half of affected individuals having experienced serious allergic reactions—highlighting the need for more effective preventive therapies.
Clinical Progress and Future Milestones
Ozureprubart is currently being evaluated in a Phase IIb study known as prestIgE, with results expected in 2027.
The drug has also shown promise beyond food allergies. Phase II data from China in chronic spontaneous urticaria demonstrated numerically higher response rates than Xolair after a single dose.
However, the acquisition excludes certain regions. Rights for mainland China, Macau, Taiwan, and Hong Kong are not included in the transaction.
Separately, GSK also announced a change in ownership at ViiV Healthcare. Shionogi & Co. will acquire Pfizer’s 11.7% stake for $2.125 billion. Following the transaction, Shionogi’s ownership will rise to 21.7%, while GSK will retain a 78.3% controlling interest.
As of press time, RAPT Therapeutics (NASDAQ: RAPT) had a market capitalization of $1.59 billion. The stock is up more than 21% over the past three months and has surged over 265% in the past year.
Stay on top of healthcare stocks with our Healthcare Stock updates
