FDA Approves Keytruda for Advanced Endometrial Cancer

The FDA has approved Merck’s Keytruda (pembrolizumab), as a single agent, for patients with advanced endometrial carcinoma that is microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR).

At the same time, the FDA also approved the Ventana MMR RxDx panel, which was developed by Ventana Medical Systems and Roche Tissue Diagnostics, as a companion diagnostic device to select patients with dMMR in solid tumors that are eligible for treatment with Keytruda. The FDA previously approved the FoundationOne CDx from Foundation Medicine as a companion diagnostic device to select patients with MSI-H in solid tumors that are eligible for treatment with Keytruda.

David O’Malley, M.D.

“The objective response rate and duration of response observed in this trial solidify the role of Keytruda as a treatment option for these patients,” David O’Malley, M.D., division of gynecologic oncology, at The Ohio State University Wexner Medical Center and The James Comprehensive Cancer Center, said in a press release.

The approval and the new indication for Keytruda was based on the KEYNOTE-158 trial 90 patients with unresectable or metastatic MSI-H or dMMR endometrial carcinoma in Cohorts D and K. Investigators found that objective response rate was 46% and duration of response was not reached, with 68% having response durations more than 12 months and 44% having response durations more than 24 months.

The most common adverse were fatigue, musculoskeletal pain, rash, diarrhea, pyrexia, cough, decreased appetite, pruritis, dyspnea, constipation, pain, abdominal pain, nausea, and hypothyroidism.

This is the second indication for Keytruda in endometrial cancer. Keytruda is also indicated in combination with Lenvima (lenvatinib) for the treatment of patients with advanced endometrial carcinoma that is not MSI-H or dMMR.