By: Ron Winslow
Two drugs being tested for kidney cancer, including one from the hot field of immuno-oncology, proved superior in separate studies to a current standard treatment, setting the stage for new options for patients with an advanced stage of the disease.
In one of the studies, researchers said patients taking Bristol-Myers Squibb Co. ’s Opdivo had a median survival of 25 months, 5.4 months longer than patients given a drug called Afinitor, marketed by Novartis AG . The survival advantage was observed during an interim safety check in July, which prompted a halt to the study because of the significant benefit.
In the second study, a drug called cabozantinib from Exelixis Inc. kept kidney cancer in check for 7.4 months before it got worse compared with 3.8 months for Afinitor, a 42% reduction in the rate of disease progression. There was a trend toward improved survival, but researchers indicated longer follow-up is needed to determine what the advantage is.
The benefit from both treatments compared with Afinitor “is unequivocal,” according to an editorial in the New England Journal of Medicine, where both studies were published. The findings were also presented Friday at the European Cancer Congress in Vienna.
But only a fraction of patients had what researchers consider an objective response to the treatments—25% for Opdivo and 21% for cabozantinib. Complete responses, in which doctors can’t find remaining evidence of disease, were “disappointingly elusive,” the editorial said. Ways to better identify patients who might benefit or to combine the drugs with other treatments are needed to “expand the benefit spectrum,” it said.
About 338,000 new cases of kidney cancer are diagnosed world-wide and more than 100,000 die of the disease each year, researchers said. In the U.S. there are nearly 62,000 new cases and about 14,000 deaths each year, according to the American Cancer Society. About 30% of cases are diagnosed after the disease has already metastasized or spread beyond the kidney. Several new treatments—Afinitor among them—have been approved during the past decade, but generally their long-term benefit is modest at best.
Opdivo, a so-called checkpoint inhibitor that targets an immune-system brake called PD-1, works by enabling immune cells to attack cancer. In the new study, involving 821 patients, the drug improved survival even though it failed to statistically improve a related measure called progression free survival, or the time it took for the disease to worsen. That result was 4.6 months for Opdivo and 4.4 months for Afinitor. The finding may reflect the unpredictable ways tumors sometimes respond to cancer-immunotherapy.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.