David M. O’Malley, MD, Discusses Recent Approval of Pembrolizumab in Endometrial Cancer


David M. O’Malley, MD, spoke about the approval of pembrolizumab for patients with advanced endometrial carcinoma that is microsatellite instability-high or mismatch repair deficient.

David M. O’Malley, MD, director of the Division of Gynecologic Oncology at the Ohio State University Comprehensive Cancer Center-The James and professor in the Department of Obstetrics and Gynecology at The Ohio State University College of Medicine, spoke with CancerNetwork® about the recent approval of pembrolizumab (Keytruda) for patients with advanced endometrial carcinoma that is microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR).1

The phase 2 KEYNOTE-158 trial (NCT02628067), for which O’Malley was the lead investigator, led to the approval of this treatment. In total, 90 patients received pembrolizumab at 200 mg intravenously every 3 weeks until unacceptable toxicity or disease progression.2 Patients had an objective response rate of 48% (95% CI, 37%- 60%), and the duration of response was not reached.


What [is important for] these patients is an option beyond chemotherapy. In the past, the chemotherapy [options] after carboplatin and paclitaxel was quite limited in its response rate and duration of responses of only 3 to 4 months. When we see the data with regards to the recent update and publication in the Journal of Clinical Oncology, we see response rates of 48%. If you get a response, the chance that response lasts more than or equal to 3 years is approximately two-thirds. These are durable, long-lasting responses, and we may be talking about curative intent in patients with recurrent uterine cancer that is MSI-H or dMMR deficient.


  1. FDA approved pembrolizumab for advanced endometrial carcinoma. News Release. FDA. March 21, 2022. Accessed April 26, 2022. https://bit.ly/3ke9WFS
  2. O’Malley DM, Bariani GM, Cassier PA, et al. Pembrolizumab in patients with microsatellite instability-high advanced endometrial cancer: Results from the KEYNOTE-158 Study. J Clin Oncol. 2022;40(7):752-761. doi:10.1200/JCO.21.01874
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