06:15 AM EDT, 09/08/2025 (MT Newswires) -- Summit Therapeutics ( SMMT ) said Sunday that data from a phase 3 trial of its investigational antibody ivonescimab plus chemotherapy intended as a treatment for patients with certain types of metastatic non-squamous non-small cell lung cancer showed "consistent, clinically meaningful improvement" in progression-free-survival.

Overall response rates for ivonescimab were 45% compared with 34% of those receiving chemotherapy alone, with the median duration of response of 7.6 months compared 4.2 months with those not receiving the treatment

In a previous analysis of both western and Asian patients, the treatment showed a "positive trend" in improving overall survival "without achieving a statistically significant benefit" in comparison with chemotherapy plus a placebo, the company said.

However, according to a report from medical news outlet Stat News, the recent update reported by the company showed that patients treated with the drug candidate from North America and Europe saw their lung cancer return and progress faster than patients from China.

This "discordant" result could complicate the company's plans to secure approval of the drug candidate in the US and Europe, the news outlet said.

Shares of Summit fell more than 21% in recent premarket activity Monday.

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