FDA Approves Pembrolizumab for Advanced Merkel Cell Carcinoma

The FDA has granted an accelerated approval to pembrolizumab (Keytruda) for the treatment of recurrent locally advanced or metastatic Merkel cell carcinoma (MCC) in adult and children.

The accelerated approval, which is contingent on the results of a confirmatory trial, was based on the phase II CITN-09/KEYNOTE-017 trial (NCT02267603), in which pembrolizumab elicited an overall response rate (ORR) of 56% (95% CI, 41%-70%) and a complete response rate of 24% in patients who did not previously receive systemic therapy for their advanced disease.

In the multicenter, nonrandomized, open-label, trial, 50 treatment-naïve patients with recurrent locally advanced or metastatic MCC received pembrolizumab at 2 mg/kg every 3 weeks. The primary endpoints were ORR and response duration, as assessed by blinded independent central review per RECIST v1.1 criteria.

Results of the trial showed that the median response duration was not reached (range, 5.9-34.5+). Among the 28 patients with responses, 96% had response durations of greater than 6 months and 54% had response durations of greater than 12 months.

The most common adverse events (AEs) of pembrolizumab reported in at least 20% of patients who received single-agent pembrolizumab were fatigue, musculoskeletal pain, decreased appetite, pruritus, diarrhea, nausea, rash, pyrexia, cough, dyspnea, constipation, pain, and abdominal pain.

The FDA noted that the recommended pembrolizumab dose for MCC is 200 mg administered intravenously (IV) every 3 weeks for adults. For pediatric patients, the PD-1 inhibitor should be given at 2 mg/kg, up to a maximum of 200 mg, IV every 3 weeks for patients <18 years of age.

This article originally appeared on OncLive^® as “FDA Approves Pembrolizumab in Merkel Cell Carcinoma.”