By Josh Nathan-Kazis

Summit Therapeutics reported results Friday in a cancer drug trial meant to answer the biggest question in biotech: What happens when U.S. companies test promising new Chinese cancer immunotherapies in western countries?

The trial's results were mixed, but analysts were putting a positive spin on things in early morning.

The results didn't show a statistically significant difference between how long lung cancer patients who received Summit's medicine survived, and how long patients survived on a placebo. But the drug did perform better than a placebo in a different measure, which counts how long it takes for cancer to progress.

What is more, the company said the drug worked just as well in patients located in Asia as in patients elsewhere.

Summit shares were flat early Friday before plunging around 8 a.m. Eastern, They were down 21% before the market opened.

Summit is one of a growing list of U.S. drugmakers that have made deals with Chinese biopharma to license PD-1/VEGF bispecific antibodies, a new type of tumor-killer. Earlier data that suggested that Summit's drug, called ivonescimab, beat Merck's blockbuster Keytruda in a head-to-head study set off an arms race, and Merck, Pfizer, and BioNTech, among others, have all licensed their own.

Most prior data on Summit's ivonescimab had come from studies run in China. Some investors had worried that the drug wouldn't look as effective in trials run outside of Asia. About a third of patients in the results announced Friday were from western countries. A disastrous outcome would have been bad not only for Summit, but for all of the Chinese-licensed PD-1/VEGF programs.

Summit avoided that worst-case scenario on Friday. The company said that in a trial in lung cancer patients, ivonescimab in combination with chemotherapy reduced the risk of disease progression or death by 48% compared to chemotherapy alone.

Importantly, the company said that results were "consistent" between patients in Asia and outside of Asia.

The results, however, didn't show a statistically significant increase in overall survival for patients who received the treatment. The company said it saw a "positive trend" in overall survival, a measure of how long patients live after starting on a medicine, but no "statistically significant benefit."

The company said it intends to file for Food and Drug Administration approval for ivonescimab in combination with chemotherapy for this category of lung cancer patients. But it acknowledged that the FDA had told the company that it would need to show a statistically significant benefit in overall survival in order to get the drug approved.

It said that requirement will "weigh into Summit's considerations regarding the timing of a potential" FDA filing.

Analysts who cover the stock were positive on Friday. Cantor's Eric Schmidt wrote that the drug's efficacy in this particular indication matters less than the fact that the drug worked as well in trials outside of Asia as it had inside of Asia.

"Investors should care less about the actual impact the drug is having in this competitive market and care more about what HARMONi tells us as the first pivotal trial on ivonescimab in a western population," he wrote, referring to the trial by name. "Today's press release reports a best possible outcome between ivonescimab's consistency of effect across the two different populations."

Write to Josh Nathan-Kazis at josh.nathan-kazis@barrons.com

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May 30, 2025 09:27 ET (13:27 GMT)

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