Summit Therapeutics' ivonescimab shows improved survival trend in extended follow-up, easing investor doubts

A new analysis of Summit Therapeutics and Akeso's dual‑acting cancer immunotherapy ivonescimab indicates that the drug's impact on overall survival has grown with longer observation. The extended data suggest a 24% reduction in the risk of death, up from the 21% reduction reported in the original April 2025 trial.

The initial trial in second‑line, EGFR‑mutated lung cancer showed a positive trend but missed statistical significance. The updated follow‑up now mirrors results from a parallel China‑only study, with comparable outcomes in both Chinese and Western patient groups.

Investors had questioned whether the early Chinese findings would translate globally. Summit says the consistent results across regions address that concern and provide a stronger counter to prior skepticism.

Analyst Dar from Stifel described the new readout as a robust rebuttal to earlier pushback, highlighting the potential for ivonescimab to gain broader confidence among stakeholders.