FDA Approves Expanded Indication for Pembrolizumab in Locally Advanced Cutaneous Squamous Cell Carcinoma

The FDA has approved an expanded indication for pembrolizumab (Keytruda, Merck) as monotherapy in adults with recurrent, metastatic, or locally advanced cutaneous squamous cell carcinoma (cSCC) that is incurable by surgery or radiation.

The first indication for pembrolizumab in cSCC was granted in June 2020 as monotherapy for the treatment of patients with recurrent or metastatic disease that is not curable with surgery or radiation. Pembrolizumab is an anti-programmed death receptor-1 therapy that increases the ability of the body’s immune system to help detect and fight tumor cells, according to a press release.

The approval is based on data from the second interim analysis of the phase 2 KEYNOTE-629 trial, which found an objective response rate (ORR) of 50% in patients with locally advanced disease, according to the press release. Trial participants received pembrolizumab 200 mg intravenously every 3 weeks until documented disease progression, unacceptable toxicity, or a maximum of 24 months.

Among the 54 patients with locally advanced cSCC, the median age was 76 years, 80% were 65 years of age or older, 72% were male, 83% were white, and 13% were race unknown. Twenty-two percent of participants received 1 or more prior lines of therapy and 63% received prior radiation therapy.

The 50% ORR included a 17% complete response rate and a 33% partial response rate among patients with locally advanced disease. Among the 27 patients who responded to therapy, 81% had a duration of response (DOR) of 6 months or longer and 37% had a DOR of 12 months or longer. After a median follow-up of 13.4 months, the median DOR had not yet been reached.

“Keytruda has shown meaningful efficacy in patients with locally advanced or recurrent or metastatic cutaneous squamous cell carcinoma that cannot be cured by surgery or radiation,” said Vicki Goodman, MD, vice president of clinical research at Merck Research Laboratories, in the press release. “This expanded indication reinforces the role of Keytruda in this cancer type, which is the second most common form of non-melanoma skin cancer.”

Adverse reactions occurring in patients with recurrent or metastatic cSCC or locally advanced cSCC were similar to those in patients with melanoma or non-small cell lung cancer who received pembrolizumab. Grade 3 or 4 laboratory abnormalities that occurred at a higher incidence included lymphopenia (10%) and decreased sodium (10%).

The press release warned of immune-mediated adverse reactions, which can occur in any organ system or tissue and can affect multiple body systems simultaneously. They can include pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, dermatologic reactions, solid organ transplant rejection, and complications of allogeneic hematopoietic stem cell transplantation. Early identification and treatment of these adverse reactions is essential, according to the press release.

REFERENCE

FDA Approves Expanded Indiation for Merck’s KEYTRUDA (Pembrolizumab) in Locally Advanced Cutaneous Squamous Cell Carcinoma (cSCC). News release. Merck. July 6, 2021. Accessed July 6, 2021. https://www.merck.com/news/fda-approves-expanded-indication-for-mercks-keytruda-pembrolizumab-in-locally-advanced-cutaneous-squamous-cell-carcinoma-cscc/