USFDA approves Merck Keytruda plus Carboplatin, Paclitaxel for Primary Advanced or Recurrent Endometrial Carcinoma

The approval is based on data from the Phase 3 NRG-GY018 trial, also known as KEYNOTE-868, in which KEYTRUDA plus carboplatin and paclitaxel followed by KEYTRUDA alone reduced the risk of disease progression or death by 40% (HR=0.60 [95% CI, 0.46-0.78]; p<0.0001) in patients whose cancer was mismatch repair proficient (pMMR) and by 70% (HR=0.30 [95% CI, 0.19-0.48]; p<0.0001) in patients whose cancer was mismatch repair deficient (dMMR), compared to placebo with carboplatin and paclitaxel followed by placebo alone.

“This is the first Phase 3 trial to statistically evaluate an anti-PD-1 immunotherapy plus chemotherapy combination in patients with pMMR and dMMR tumors as two independent cohorts,” said Dr. Ramez N. Eskander, principal investigator, associate professor in the Department of Obstetrics, Gynecology, and Reproductive Services at University of California San Diego School of Medicine and gynecologic oncologist at Moores Cancer Center at University of California San Diego Health. “The addition of pembrolizumab to chemotherapy represents a new frontline therapeutic option for patients with primary advanced or recurrent endometrial carcinoma, demonstrating a statistically significant and clinically meaningful progression-free survival benefit compared to chemotherapy alone, regardless of mismatch repair status.”

For patients whose cancer was pMMR, median progression-free survival (PFS) in the KEYTRUDA plus carboplatin and paclitaxel arm was 11.1 months (95% CI, 8.7-13.5) versus 8.5 months (95% CI, 7.2-8.8) for the placebo plus carboplatin and paclitaxel arm; for patients whose cancer was dMMR, median PFS was not reached (95% CI, 30.7-NR) in the KEYTRUDA plus carboplatin and paclitaxel arm versus 6.5 months (95% CI, 6.4-8.7) for the placebo plus carboplatin and paclitaxel arm.

This trial was sponsored by the U.S. National Cancer Institute (NCI), part of the National Institutes of Health. NRG Oncology designed and led the trial with funding from the NCI and participation from all the National Clinical Trials Network (NCTN) groups. Merck provided funding and support through a Cooperative Research and Development Agreement (CRADA) between Merck and NCI.

“Endometrial cancer is now the most common gynecologic cancer in the U.S., and deaths from the disease are projected to surpass deaths from ovarian cancer in 2024, underscoring the need for treatment advances for more patients,” said Dr. Gursel Aktan, vice president, global clinical development, Merck Research Laboratories. “This approval represents the first and only anti-PD-1-based option for adult patients with primary advanced or recurrent endometrial carcinoma regardless of mismatch repair status, building on the established role of KEYTRUDA in certain types of advanced endometrial carcinoma as monotherapy and in combination with LENVIMA.”

In the U.S., KEYTRUDA has two additional approved indications in endometrial carcinoma. One indication, based on KEYNOTE-775/Study 309, is in combination with LENVIMA (lenvatinib), in collaboration with Eisai, for the treatment of adult patients with advanced endometrial carcinoma that is pMMR, as determined by an FDA-approved test, or not microsatellite instability-high (MSI-H), who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation. The second indication, based on KEYNOTE-158, is as a single agent, for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation.

This approval was reviewed under Project Orbis, an initiative of the FDA Oncology Center of Excellence that provides a framework for concurrent review of oncology drugs among its international partners. Under this project, the NRG-GY018/KEYNOTE-868 application is still under review by health authorities in Israel, Canada, Australia, Singapore, Brazil and the United Kingdom.