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A hotly debated lung cancer drug cut the risk of death by 34% in a late-stage trial in China
An experimental lung cancer drug from Akeso and Summit Therapeutics reduced the risk of death by 34% in a closely watched late-stage trial, according to results released Sunday.
When combined with chemotherapy, the drug kept people with squamous non-small-cell lung cancer alive for a median of four months longer than the standard combination of immunotherapy and chemotherapy, a result that was statistically significant, according to an abstract released Sunday ahead of a presentation at the American Society of Clinical Oncology's annual meeting. The Phase 3 trial was conducted in China, and a global Phase 3 study is ongoing.
"The fact that it shows an improvement in overall survival in a difficult-to-treat patient population is very encouraging," said Dr. Suresh Ramalingam, executive director of the Winship Cancer Institute of Emory University. "I'm mindful of the fact that this trial was done exclusively in China, and that brings up the question of how do these data apply to patient populations outside of China, and that will require future investigations."
Called ivonescimab, the bispecific antibody targets PD-1 — similar to Merck's best-selling drug Keytruda —and VEGF — similar to Roche's Avastin. It's become the subject of intense debate in the oncology and investment communities. Some say ivonescimab and similar drugs could be a successor to Merck's wildly successful cancer drug Keytruda, while others warn it'll disappoint like other once-promising ideas such as drugs targeting TIGIT, an immune receptor.
The dueling narratives are reflected in the stock price of U.S.-based Summit Therapeutics, which licensed the rights to ivonescimab outside of China from Akeso. Shares of Summit have skyrocketed nearly 600% in the two years since Summit said ivonescimab more effectively controlled tumors than Keytruda in a separate China trial. The stock has slid in the past month over concerns the drug won't be as effective in a global population.
Previous studies have showed ivonescimab can effectively control tumors, an endpoint known as progression-free survival. That's typically not enough to seek approval from the U.S. Food and Drug Administration, which wants proof that cancer drugs can keep people alive longer. Older VEGF drugs that effectively controlled tumors struggled to improve survival, which raised doubts that ivonescimab's early promise would hold.
In the Harmoni-6 trial being presented Sunday, ivonescimab combined with chemotherapy kept people alive for a median of 27.9 months versus 23.7 months for people who received a standalone PD-1 drug and chemotherapy, an improvement of four months.
"It's not clear how meaningful that is," said Dr. Deborah Doroshow, associate professor of medicine, hematology and medical oncology at the Icahn School of Medicine at Mount Sinai. "It's certainly, it's not two months, but it's also not a huge difference, and I think in terms of whether or not living four months longer is meaningful absolutely depends on the person who is living it."
People receiving immunotherapy in the control group lived an average of six months longer than expected, raising questions about whether the trial enrolled a representative patient population and whether the advantage of ivonescimab might be better than reported in the study, said Doroshow, who serves on the steering committee for the ongoing Harmoni-3 global trial of ivonescimab.
One possible reason for the discrepancy is that the study was conducted in China, where people have historically responded better to standalone PD-1 and VEGF drugs, said Emory's Ramalingam. The only way to determine whether combining the two in one molecule produces different results for broader populations is to run additional studies in the West, he said.
Until then, Ramalingam called the trial results "good news" for Chinese patients.
"There is a new approach in squamous cell lung cancer that extends survival by about four months, which is a substantial improvement given that this is a patient population where progress has come in small steps," he said.
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