A new drug combination to fight advanced renal cell carcinoma, the most common form of kidney cancer, generated unprecedented results in an early-phase clinical trial, according to Michael B. Atkins, MD, deputy director, Georgetown Lombardi Comprehensive Cancer Center and principal investigator for the study.
“The combination doubled the efficacy of the drugs when used alone and the treatment was found to be tolerable,” Atkins reported. “Specifically, over 90 percent of patients exhibited tumor shrinkage and the disease was kept under control for a median of over 20 months.” The study assessed the effect of combining an anti-angiogenesis agent (axitinib) with an immunotherapy agent (pembrolizumab). Axitinib inhibits angiogenesis, the process of blood vessels forming to feed a tumor. It was previously approved by the FDA as a second-line treatment for advanced kidney cancer. The immunotherapy agent, pembrolizumab, blocks a self-defense mechanism used by cancer cells to evade attack and destruction by the body’s immune cells. It is FDA-approved for the treatment of patients with several cancer types but has only had limited study in patients with kidney cancer.
The investigators started their phase I clinical trial of this combination in 2014 and enrolled 52 advanced renal cell carcinoma patients who had not previously been treated for the disease. Seventy-three percent of patients experienced significant tumor shrinkage in response to the combination therapy. By March 2017, 25 patients were still being treated, with 22 receiving the drug combination and 3 receiving pembrolizumab only. Overall survival results are as yet incomplete as 88 percent of the patients were still alive at a minimum 18 months after starting therapy.
Atkins reported that a randomized phase III trial is underway to compare this drug combination to the previous standard-of-care regimen for kidney disease. “This combination could present a major advance in the treatment of his disease,” he notes, “as well as help define effective combinations of similar drugs for other cancers.”
The work was sponsored by Pfizer Inc. in collaboration with Merck (known as MSD outside the U.S. and Canada). Atkins has been a paid consultant to Pfizer and Merck, as well as other pharmaceutical companies, on cancer-related issues including, but not limited to, kidney cancer.