Summit Therapeutics Stock Gains on Updated Lung Cancer Drug Data

Shares of Summit Therapeutics (NASDAQ: SMMT) rose 3% in trading on Wednesday following the company's release of updated overall survival (OS) data from its late-stage clinical trial for the cancer therapy ivonescimab.

Updated HARMONi Trial Results

Summit announced updated findings from its global Phase III HARMONi study, which evaluates ivonescimab combined with chemotherapy. The trial focuses on patients with EGFR-mutated, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) who were previously treated with a third-generation EGFR tyrosine kinase inhibitor.

The latest analysis, with a data cut-off in June 2026, revealed key findings:

• Western patients in the trial achieved an overall survival hazard ratio of 0.76, a result the company noted was consistent with Asian patients in the study.
• The median follow-up time for the Western patient group extended to 23.2 months, a substantial increase from the 9.2 months at the time of the primary analysis in April 2025.

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Summit also reported that the drug's safety profile remained acceptable and manageable, with no new safety signals identified in the updated data.

Context and Regulatory Path

The new data provides further clarity after the initial OS analysis in April 2025 showed a positive trend with a hazard ratio of 0.79 but did not achieve statistical significance (p-value of 0.057). However, the trial had previously met its other primary endpoint, demonstrating a statistically significant benefit in progression-free survival (PFS).

This updated information is critical as Summit moves forward with its regulatory submission. The company has provided the new analysis to the U.S. Food and Drug Administration (FDA) as part of its ongoing Biologics License Application (BLA) review. The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of November 14, 2026, for a decision on the drug's approval.