Keytruda (pembrolizumab) is approved for treatment of patients with advanced melanoma that no longer responds to other drugs. It is the first FDA-approved drug that blocks a cellular pathway called PD-1, which restricts the body's immune system from attacking melanoma cells.
"This is the latest in a string of major breakthroughs in melanoma treatment that will galvanize the field of melanoma research and cancer treatment," Wendy Selig, president of the Melanoma Research Alliance, said in a news release from the group. "Pembrolizumab has demonstrated real potential to save the lives of late-stage melanoma patients who had little hope of survival just a few years ago."
According to the FDA, the drug's approval was based on a clinical trial of 173 patients with advanced melanoma. It found that at the recommended dose of 2 milligrams per kilogram, about 24 percent of patients saw their tumors shrink. This effect lasted at least 1.4 months to 8.5 months and continued for a longer period in most patients, the FDA said.
"Keytruda is the sixth new melanoma treatment approved since 2011, a result of promising advances in melanoma research," Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research, said in an agency news release.
"Many of these treatments have different mechanisms of action and bring new options to patients with melanoma," he added.
Another patient advocacy group agreed.
"The approval of pembrolizumab is a tremendous step forward for the melanoma patient community, as this is the most promising and positive patient response to a melanoma treatment to date," Tim Turnham, executive director of the Melanoma Research Foundation, said in a statement. He noted that other drugs that target the PD-1 cellular pathway are in development, and may be approved soon.
However, Turnham cautioned that "pembrolizumab will not be a treatment option for every person with late-stage melanoma and not everyone who takes it will have positive results."
He added that "while many people who were administered pembrolizumab in clinical trials saw tremendous benefit, a treatment that successfully kills melanoma cells and prevents recurrence in every patient has not yet been developed. That is the ultimate goal."
Melanoma accounts for about 5 percent of all new cancer cases in the United States. About 76,100 Americans will be diagnosed with melanoma this year and 9,710 will die from it, according to the U.S. National Cancer Institute.
Keytruda is marketed by Merck & Co.