Pembrolizumab Approved by FDA for Cutaneous Squamous Cell Carcinoma
Posted: Friday, June 26, 2020
On June 24, the U.S. Food and Drug Administration (FDA) approved the PD-1 inhibitor pembrolizumab (Keytruda) for patients with recurrent or metastatic cutaneous squamous cell carcinoma that is not curable by surgery or radiation therapy. This approval comes nearly 2 months after the FDA’s approval of a new dosing regimen for pembrolizumab in patients with Merkel cell carcinoma. Based on pharmacokinetic data in patients with melanoma, the recommended doses for pembrolizumab are 200 mg every 3 weeks or 400 mg every 6 weeks.
The FDA approval in squamous cell carcinoma was based on data from the multicenter, multicohort, open-label KEYNOTE-629 clinical trial. Patients received 200 mg of pembrolizumab every 3 weeks until disease progression, unacceptable toxicity, or a maximum of 24 months. Patients’ tumor status was checked every 6 weeks during the first year and every 9 weeks during the second year. The trial excluded patients who had prior treatment with an anti–PD-1, anti–PD-L1, or anti–CTLA-4 antibody as well as patients with autoimmune disease or a medical condition that required immunosuppression.
The major efficacy outcome, overall response rate, was 34% (95% confidence interval = 24%–44%). After more than 13.1 months, the second major efficacy outcome, median response duration, had not been reached.
Common adverse reactions in patients with cutaneous squamous cell carcinoma administered pembrolizumab included fatigue, musculoskeletal pain, decreased appetite, pruritus, diarrhea, nausea, rash, pyrexia, cough, dyspnea, constipation, pain, and abdominal pain. Immune-mediated side effects for pembrolizumab were pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, and adverse skin reactions.
For full prescribing information on pembrolizumab, visit accessdata.fda.gov.