FDA Approves Keytruda for Relapsed/Refractory PMBCL

The FDA has granted an accelerated approval to Keytruda (pembrolizumab) for the treatment of adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma (PMBCL), or those who have relapsed after 2 or more prior lines of therapy.

The approval is based on results from 53 patients with relapsed/refractory PMBCL enrolled in the multicenter, open-label, single-arm trial, KEYNOTE‑170 trial (NCT02576990). At the median follow-up of 9.7 months, the overall response rate was 45 percent, comprising a complete response rate of 11 percent and a partial response rate of 34 percent.

The median time to initial objective response was 2.8 months, and the median duration of response was not reached.

The FDA noted in its approval statement that the agency does not recommend Keytruda for patients with PMBCL who require urgent cytoreductive therapy.

In KEYNOTE-170, all-grade adverse events (AEs) occurring in at least 10 percent of patients included musculoskeletal pain, upper respiratory tract infection, pyrexia, fatigue, cough, dyspnea, diarrhea, abdominal pain, nausea, arrhythmia and headache.

Eight percent of patients discontinued treatment due to AEs. The Keytruda dose was interrupted due to AEs in 15 percent of patients. Corticosteroid therapy was required for AEs in 25 percent of patients. Twenty-six percent of patients had serious AEs.

Keytruda has additional approved indications in melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, urothelial carcinoma, gastric cancer, cervical cancer, and microsatellite instability—high solid tumors.