GSK has agreed to acquire U.S. biotech Rapt Therapeutics for $2.2 billion, a move that bolsters its pipeline in food allergies. The deal values Rapt at $58 per share, nearly double its Nasdaq closing price on Monday, signaling a premium for its promising clinical-stage programs.

This acquisition arrives as pharmaceutical giants race to develop treatments for immune-mediated diseases, a crowded but lucrative field. GSK gains Rapt's experimental drug for eosinophilic esophagitis, a chronic condition with limited therapies, adding to its immunology portfolio after recent divestments.

Investors will watch for regulatory approval and integration timelines. The deal highlights GSK's strategy to offset looming patent cliffs with bolt-on acquisitions in specialized, high-growth areas, a trend likely to continue across the biotech sector.