Expanded Indication for an Immune Checkpoint Inhibitor in Endometrial Cancer
The FDA has approved dostarlimab-gxly plus chemotherapy to treat more patients with endometrial cancer.
The U.S. Food and Drug Administration (FDA) has approved dostarlimab-gxly (Jemperli) in combination with the chemotherapies carboplatin and paclitaxel, followed by dostarlimab-gxly alone, for the treatment of adult patients with advanced or recurrent endometrial cancer.
Dostarlimab-gxly is an immunotherapy called an immune checkpoint inhibitor. It blocks the protein PD-1 on the surface of immune cells, releasing one of the immune system’s natural brakes. This helps the immune cells more effectively attack the cancer cells.
Dostarlimab-gxly plus carboplatin and paclitaxel, followed by single-agent therapy with dostarlimab-gxly, was previously approved to treat patients with advanced or recurrent endometrial cancer whose tumors were mismatch repair deficient (dMMR) or had high microsatellite instability (MSI-H)—two biomarkers that have been associated with response to immune checkpoint inhibitors. The current approval allows for the use of this regimen in patients with endometrial cancer whose tumors are not dMMR or MSI-H.
The current approval was based on results from the randomized, multicenter, double-blind, placebo-controlled, phase III RUBY clinical trial. Researchers randomly assigned (1:1) 494 patients with advanced or recurrent endometrial cancer to receive dostarlimab-gxly plus carboplatin and paclitaxel, followed by dostarlimab-gxly alone, or to receive placebo plus carboplatin and paclitaxel, followed by placebo alone.
In the overall study population, which included patients with and without dMMR or MSI-H tumors, patients in the dostarlimab-gxly arm survived for significantly longer after treatment—a median of 44.6 months compared with 28.2 months in the placebo arm. Patients in the dostarlimab-gxly arm also survived for a median of 11.8 months without disease progression, compared with 7.9 months in the placebo arm.
The recommended dose of dostarlimab-gxly is 500 mg with carboplatin and paclitaxel every three weeks for six cycles, followed by 1,000 mg of dostarlimab-gxly alone every six weeks until disease progression or unacceptable toxicity, up to three years.
Endometrial cancer is the most common type of uterine cancer. It arises from cells in the endometrium, the lining of the uterus. According to federal statistics, it was estimated that 67,880 individuals would be diagnosed with uterine cancer and 13,250 patients would die of the disease in the United States in 2024.
The FDA rendered its decision on August 1, 2024.
