FDA Grants Priority Review to Pembrolizumab for Treatment of Merkel Cell Carcinoma

The US Food and Drug Administration (FDA) has accepted and granted a priority review for a new supplemental Biologics License Application (sBLA) seeking accelerated approval for Merck’s pembrolizumab (KEYTRUDA), an anti-PD-1 therapy, for the treatment of adult and pediatric patients with recurrent locally advanced or metastatic Merkel cell carcinoma.

The decision was based on data pertaining to overall response rate and duration of response gleaned from KEYNOTE-017, a phase 2 trial in which were presented at the American Society of Clinical Oncology 2018 (ASCO 2018) annual meeting.

“Merkel cell carcinoma, a rare type of skin cancer, is an aggressive and fast-growing disease that has been associated with mortality rates higher than other types of skin cancer, including melanoma,” Dr. Scot Ebbinghaus, vice president of clinical research at Merck Research Laboratories, said in a recent statement. “KEYNOTE-017 represents the longest observation to date of patients with advanced Merkel cell carcinoma receiving anti-PD-1 therapy in the first-line setting and demonstrated durable tumor control in patients.”

The therapy works by boosting the ability of the immune system to detect and battle tumor cells. Pembrolizumab is a humanized monoclonal antibody that stops PD-1 from interacting with its ligands, PD-L1 and PD-L2; by doing this, it activates T lymphocytes that could affect tumor cells as well as healthy cells, according to Merck.

Previously, in July 2017, pembrolizumab was granted a breakthrough therapy designation for this indication.

“We look forward to working closely with the FDA throughout the review process and to bringing KEYTRUDA to patients with Merkel cell carcinoma,” Dr. Ebbinghaus added.

The Prescription Drug User Fee Act (PDUFA) date for the therapy has been set to the end of this year—December 28, 2018.

Over 90% of those diagnosed with Merkel cell carcinoma—an aggressive, rare skin cancer—are over the age of 50. This cancer has an increased likelihood of spreading to other parts of the body than most other types of skin cancer. About 2,500 cases of Merkel cell carcinoma are diagnosed annually in the United States, and historically, the cancer is estimated to have an 18-month survival rate of around 30%.