Global healthcare giant GSK（GSK）has agreed to acquire U.S.-based biotech firm RAPT Therapeutics （RAPT）for approximately $2.2 billion in cash, gaining worldwide rights to its experimental food allergy drug ozureprubart outside mainland China, Macau, Taiwan, and Hong Kong.
The deal, announced Tuesday, sent RAPT shares soaring more than 60% to $57.50 in premarket trading, nearing GSK’s offer price of $58 per share — a 65% premium to RAPT’s closing price on the last trading day before the announcement.
Ozureprubart is a monoclonal antibody designed to block a protein responsible for about 94% of severe food allergy reactions. The therapy aims to provide protection with less frequent dosing than existing treatments and is currently in Phase 2 clinical trials for patients aged 12 to 55, with data expected next year.
If successful, it could compete with Genentech’s Xolair, which is administered every two to four weeks. Ozureprubart is being tested with dosing intervals of up to 12 weeks. More than 17 million people in the U.S. suffer from food allergies, including over 1.3 million who experience severe reactions. “Ozurprubart… aligns with our strategy to acquire assets that address validated targets and clear unmet medical needs,” said GSK Chief Scientific Officer Tony Wood.
The acquisition marks one of the first major strategic moves by GSK’s new CEO, Luke Miels, who took over just weeks ago. It comes as the company prepares for the patent expiry of its blockbuster HIV drug dolutegravir in 2028 and aims to deliver more than £40 billion ($54 billion) in annual revenue by 2031.
Jefferies analyst Michael Leuchten noted the deal reflects the kind of targeted acquisitions GSK needs to pursue consistently amid upcoming patent losses. However, Barclays analysts pointed out that ozureprubart is at an earlier stage than some investors might have expected, suggesting some may have hoped for a larger or more near-term accretive transaction under the new leadership.
GSK has been focused on building a portfolio of long-acting therapies. Last December, it gained U.S. approval for a twice-yearly asthma treatment. Leuchten added that GSK will likely continue to evaluate similar strategic assets.
The acquisition is expected to close in the first quarter of this year, pending regulatory approvals.
