Summit Therapeutics Stock Plunges 25% on Cancer Drug Setback
Updated trial data for lung cancer therapy ivonescimab raises concerns over efficacy in Western patients, clouding its FDA approval path.
Shares of Summit Therapeutics (SMMT) plunged more than 25% in premarket trading after the biopharmaceutical company released troubling new data from a pivotal trial for its lung cancer therapy, ivonescimab.
The updated, longer-term results from the global Phase III HARMONi study failed to validate earlier promising signals observed in studies conducted in China. More significantly, the data indicated for patients in North America and Europe, creating substantial uncertainty around the drug's path to regulatory approval in Western markets.
The setback sent shockwaves through the investment community, which offered sharply divided perspectives. Leerink Partners, reiterating an underperform rating, noted that the readout 'confirmed the hypothesis that survival signals would degrade from China to North America & Europe.' The firm stated it believes it is ' based on HARMONi.'
Other analysts viewed the situation with more nuance. Truist characterized the study as a 'narrow miss' but acknowledged the regulatory path is now 'reliant on an act of leniency by the FDA.' Offering a more bullish counterpoint, Citizens Bank suggested that the updated results confirm ivonescimab’s efficacy and that , a view that stood in stark contrast to the stock's precipitous fall.
The future of ivonescimab now hangs in the balance. Summit Therapeutics confirmed it has not yet discussed these latest findings with the U.S. Food and Drug Administration. Investors and patients alike will be closely watching for updates on the company's engagement with regulators, which will determine the fate of what was once considered a highly promising cancer therapy.