Summit Therapeutics Stock Plunges 23%: The Ivonescimab Update Shaking Its Keytruda Challenge
Summit Therapeutics shares fell 23% to $16.60 after an interim HARMONi-3 trial update for ivonescimab showed no early benefit. The study remains blinded, with final progression-free survival data expected in late 2026. Merck shares rose 3%. A key survival readout from a China-run trial is set for May 31 at ASCO.