MW An experimental lung-cancer drug could replace Keytruda one day. But investors aren't wowed.

By Jaimy Lee

The highly anticipated study found that ivonescimab reduced the risk of death by 34% compared with another drug

Summit Therapeutics and Akeso shared more data for their experimental lung-cancer drug at a cancer conference over the weekend.

A promising new cancer drug helped reduce the risk of death by 34% in patients with the most common form of lung cancer, but investors appeared to be ambivalent to the data.

The highly anticipated readout is for ivonescimab, a drug developed by Akeso, a Chinese biotech that licensed the medication to Summit Therapeutics, a U.S. company led by an influential biotech entrepreneur.

The stocks of both companies had a mixed response to the data on Monday morning. Summit's shares (SMMT) were up 2.6% in premarket trading, though Akeso's Hong Kong-listed stock (HK:9926) fell 1.9%.

Two years ago this week, Summit shared data from a Phase 3 trial that showed for the first time that another drug - ivonescimab - was better than Merck's $(MRK)$ flagship drug Keytruda at treating patients with lung cancer. The readout was a surprise to investors, and for Summit, which licensed ivonescimab for $500 million upfront in 2022, a good thing. The company's stock nearly quadrupled in one day to $10.92.

The drug has since been approved in China, though it's still being tested in Western patients, for whom there is high demand for new lung-cancer treatments. The fact that the study was conducted only in China, in a patient population largely younger than 65, is a concern for investors.

"King Keytruda's reign continues," BMO Capital Markets analyst Evan David Seigerman told investors. "Ivonescimab [is] hardly the competitive threat (at this time) some had feared."

About 150,000 people in the U.S. were diagnosed in 2020 with squamous non-small cell lung cancer. One reason it's challenging to treat is that this type of cancer can become resistant to available medications. That's why a drug that can target two pathways, which is what ivonescimab does, has been thought to be better for patients than Keytruda, which targets one.

Ivonescimab works by targeting two proteins: PD-1, the same target as Keytruda, and VEGF, which is how a drug like Regeneron's $(REGN)$ macular degeneration Eylea works.

"Despite recent advances in immunotherapy and targeted therapy, most patients with non-small-cell lung cancer continue to have disease progression and develop resistance to current treatments," the authors of a commentary wrote in The Lancet. "Consequently, there is an urgent need for more effective treatment approaches that provide durable benefit for a greater number of patients."

The latest Phase 3 data were released Sunday at a premier cancer conference in Chicago and published in The Lancet. It showed that the ivonescimab-chemotherapy combo led to a significant increase in overall survival after about two years when compared with BeOne Medicines' (CN:688235) Tevimbra-chemo combo. The trial took place in China, enrolling patients who had never been treated for advanced squamous non-small cell lung cancer. About 93% of the participants were men, with a median age of 64 years old. Most of them used to smoke.

There were no new safety signals, though about 41% of patients who received the ivonescimab-chemo combo reported adverse events.

No PD-1xVEGF bispecifics have been approved in the U.S. yet, though Summit is expecting a Food and Drug Administration decision on the ivonescimab-combo in a specific type of squamous non-small cell lung cancer in November.

"The decision we made in December 2022 to enter into a partnership specifically with Akeso and accelerate the global clinical development plan of this potentially landscape-changing compound in ivonescimab is further validated with these groundbreaking results," Robert Duggan, Summit's co-CEO, said in a news release. Duggan is well-known in biopharma circles as the former CEO of Pharmacyclics, a cancer biotech that was sold to AbbVie for $21 billion in 2015.

The emergence of ivonescimab has also raised questions about what's next for Keytruda, the world's top-selling cancer medicine and until recently the biggest drug in the world by sales. Merck has made several deals for new drugs to prepare for the 2028 patent expiration of Keytruda, which produced $32 billion in sales last year alone.

-Jaimy Lee

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June 01, 2026 08:06 ET (12:06 GMT)

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