GSK Strengthens Immunology Pipeline with Major Biotech Acquisition

In a significant move to bolster its immunology portfolio, pharmaceutical giant GSK plc has agreed to acquire the U.S.-based biotechnology firm RAPT Therapeutics. The all-cash transaction, valued at approximately $2.2 billion, underscores GSK's strategic commitment to expanding its presence in the allergy and immunology treatment space.

The centerpiece of this deal is an investigational drug known as ozureprubart, an anti-IgE antibody currently in mid-stage clinical trials. This potential therapy represents a novel approach to managing food allergies, a condition affecting a substantial patient population. Industry observers note the acquisition price translates to a payment of $58.00 per share to RAPT Therapeutics' stockholders.

A primary clinical advantage of ozureprubart lies in its dosing schedule. Existing standard therapies often require injections every two to four weeks. In contrast, the candidate from RAPT is designed for administration only once every eight to twelve weeks, which could significantly reduce the treatment burden for patients.

Addressing a Substantial Unmet Need

The market opportunity is considerable. In the United States alone, more than 17 million individuals live with diagnosed food allergies. Ozureprubart could offer a new alternative, particularly for pediatric patients and the estimated 25% of sufferers who do not respond adequately to current treatment options. If successful, the drug has the potential to redefine the standard of care in this therapeutic area.

Should investors sell immediately? Or is it worth buying RAPT Therapeutics?

Upon closing the acquisition, GSK will secure global rights to ozureprubart. The sole exception is Greater China, a region encompassing Macau, Taiwan, and Hong Kong, where rights are not included in the transaction.

Clinical Timeline and Integration

GSK anticipates finalizing the deal within the first quarter of 2026. The clinical development program for ozureprubart will continue in parallel. Key data readouts from the ongoing Phase 2b "prestIgE" study for food allergies are projected for 2027.

The drug's potential extends beyond food allergies. Encouraged by prior positive results, RAPT Therapeutics initiated a Phase 3 clinical trial in late 2026 to evaluate ozureprubart for treating chronic spontaneous urticaria (CSU), commonly known as chronic hives. This program will now advance under GSK's stewardship.

This acquisition positions GSK to potentially introduce a differentiated, long-acting therapy into a high-need immunology market, pending successful clinical outcomes and regulatory approvals.