Earlier today the US Food and Drug Administration (FDA) granted accelerated approval to the anti-PD-1 drug pembrolizumab (Keytruda) for the treatment of melanoma patients with relapsed or refractory disease.
Pembrolizumab (formerly MK-3475) becomes the first approved anti-PD-1 drug and is intended for use following treatment with ipilimumab, or after treatment with ipilimumab and a BRAF inhibitor in patients who carry a BRAF mutation.
“Keytruda is the sixth new melanoma treatment approved since 2011, a result of promising advances in melanoma research,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, in a press release. “Many of these treatments have different mechanisms of action and bring new options to patients with melanoma.”
The FDA previously approved ipilimumab, vemurafenib, peginterferon alfa-2b, trametinib, and dabrafenib for the treatment of melanoma.
The trial that led to the approval of pembrolizumab included 173 melanoma patients whose disease had progressed following treatment. All participants received the study drug, with patients randomized to receive the recommended dose of 2 mg/kg, or a higher dose of 10 mg/kg.
The overall response rate in patients who received pembrolizumab at the 2 mg/kg dose was approximately 24%. The duration of response was at least 1.4 to 8.5 months, with most patients having a response that continued beyond that. The response rate at the 10 mg/kg dose was comparable to the lower dose.
The most common adverse events reported in patients who received pembrolizumab were pruritus, rash, fatigue, nausea, cough, constipation, arthralgia, decreased appetite, and diarrhea. Though uncommon, the drug also carries the potential for severe immune-mediated adverse events involving the lungs, liver, colon, and hormone-producing glands.
It is estimated that in the United States this year, 76,100 patients will be diagnosed with melanoma and 9,710 will die from the disease, according to the National Cancer Institute.