Pembrolizumab Extends FDA Indication to Locally Advanced cSCC

The FDA announced that it approved an expanded indication for pembrolizumab as monotherapy for the treatment of locally advanced cutaneous squamous cell carcinoma (cSCC).

Approval comes after the release of data from a second interim analysis of a multicenter, multicohort, nonrandomized, open-label phase 2 trial, KEYNOTE-629. In the trial, patients with recurrent or metastatic cSCC or locally advanced cSCC received pembrolizumab 200 mg intravenously every 3 weeks until documented disease progression, unacceptable toxicity, or maximum 24 months. Tumor status was assessed every 6 weeks during the first year and every 9 weeks during the second year of treatment. Primary endpoints were objective response rate (ORR) and duration of response (DOR) as assessed by a blinded independent centra review. In total, 54 patients with locally advanced cSCC were treated during the study.

Pembrolizumab demonstrated an objective response rate of 50% (95% CI, 36-64) in patients with locally advanced cSCC. Further, 17% had a complete response rate and 33% had partial response. Of these 27 responders, 81% had a DOR of at least 6 months and 37% had a DOR of at least 12 months.

Adverse reactions in this trial were similar to reactions occurring in the 2799 patients with melanoma or nonsmall cell lung cancer who received pembrolizumab.

Pembrolizumab inhibits programmed death receptor 1 (PD-1) from interacting with PD-L1 and PD-L2, increasing the body’s ability to detect and fight tumor cells. It is indicated for dermatologic malignancies melanoma, Merkel cell carcinoma, and cSCC. Other indications include nonsmall cell lung cancer, head and neck squamous cell carcinoma, classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, urothelial carcinoma, microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) cancer, MSI-H or dMMR colorectal cancer, gastic cancer, esophageal cancer, cervical cancer, hepatocellular carcinoma, renal cell carcinoma, tumor mutational burden-high cancer, and triple-negative breast cancer.

Reference
FDA approves expanded indication for Merck’s KEYTRUDA® (pembrolizumab) in locally advanced cutaneous squamous cell carcinoma (cSCC). Press release. Merk. July 6, 2021. Accessed July 7, 2021. https://www.merck.com/news/fda-approves-expanded-indication-for-mercks-keytruda-pembrolizumab-in-locally-advanced-cutaneous-squamous-cell-carcinoma-cscc/