Summit Therapeutics shares fall 25.29% premarket due to mixed data from lung cancer drug trial.

Summit Therapeutics Inc. rose 3.37% in premarket trading. The company's shares had previously dropped 21% in premarket trading on Monday following mixed results from a longer-term follow-up of North American and European patients in its late-stage lung cancer drug trial. The study results showed that the drug, ivonescimab, had stronger benefit in patients with non-small cell lung cancer (NSCLC) in China, compared with patients in the other two regions. While the study continues to read positively in aggregate, the details on the Asian vs. non-Asian subgroups were worse than expected.