Summit Therapeutics' ivonescimab misses interim goal, shares tumble 27% as trial setback raises doubts

Summit Therapeutics reported that its experimental immunotherapy ivonescimab failed to achieve statistical significance at an interim analysis of the late-stage HARMONi-3 trial in frontline non‑small cell lung cancer. The news sent the company’s shares down about 27% on the trading day.

The HARMONi-3 study pits ivonescimab plus chemotherapy against Merck's Keytruda in a head‑to‑head comparison. Summit had planned the interim look to potentially accelerate regulatory approval if the data were strongly positive.

Because the interim endpoint was missed, the company said a final analysis will be performed in the second half of the year. Investors questioned the decision to schedule the interim analysis, suggesting it added risk without clear upside.

The roundup also noted a pending take‑private transaction for Esperion Therapeutics, a label expansion approval for Axsome Therapeutics, and an FDA advisory committee vote against an AstraZeneca breast‑cancer drug.