Ozureprubart: A New Hope for Allergy Sufferers

RAPT’s lead candidate, ozureprubart, is a lab-engineered therapy designed to prevent inflammation caused by allergic reactions. The drug works by targeting the specific antibody responsible for the body’s immune response.

Analysts suggest that ozureprubart has the potential to become a leading treatment compared to existing drugs like Xolair, thanks to its broader efficacy and durability lasting up to 16 weeks. The drug is currently in advanced clinical trials (Phase 2b) for food allergies, with a transition to Phase 3 anticipated by late 2026.

GSK’s Strategy: Growth Amidst Market Challenges

The acquisition comes at a critical time for GSK, which is striving to reach an annual revenue target of over £40 billion by 2031. To achieve this, the company must find new revenue streams to offset losses from top-selling drugs going off-patent, while also navigating economic uncertainties such as U.S. tariffs.

In addition to the RAPT deal, GSK announced that Japan’s Shionogi & Co will increase its stake in the ViiV Healthcare venture following Pfizer’s departure. GSK will retain its 78.3% majority stake and receive a special dividend of $250 million from the move.

Market and Investor Reaction

Following the announcement on Tuesday, RAPT’s stock surged 63% in premarket trading on Wall Street, while GSK’s shares saw a minor decline of approximately 1% in London. RAPT’s inclusion in the S&P Biotechnology Select Industry Index in December 2025 had already increased institutional awareness, but the acquisition by a giant like GSK marks a new, more established chapter for investors.