MSD's Keytruda (pembrolizumab) has been cleared for use in the US as monotherapy for the treatment of patients with recurrent or metastatic cutaneous squamous cell carcinoma (cSCC) not curable by surgery or radiation.

Clearance is based on data from the Phase II KEYNOTE-629 trial, in which Keytruda demonstrated meaningful efficacy and durability of response, with an objective response rate (ORR) of 34%, including a complete response rate of 4% and a partial response rate of 31%.

Also, among responding patients, 69% had ongoing responses of six months or longer. After a median follow-up time of 9.5 months, the median duration of response (DOR) had not been reached.

“Cutaneous squamous cell carcinoma is the second most common form of skin cancer,” said Dr. Jonathan Cheng, vice president, clinical research, Merck Research Laboratories. “In KEYNOTE-629, treatment with KEYTRUDA resulted in clinically meaningful and durable responses.”

The approval includes both three and six week dosing options.

Keytruda is an anti-PD-1 therapy that works by increasing the ability of the body’s immune system to help detect and fight tumour cells, approved across a range of cancer indications.