Dostarlimab for Primary Advanced or Recurrent Endometrial Cancer.

BACKGROUND: Dostarlimab is an immune-checkpoint inhibitor that targets the programmed cell death 1 receptor. The combination of chemotherapy and immunotherapy may have synergistic effects in the treatment of endometrial cancer. METHODS: We conducted a phase 3, global, double-blind, randomized, placebo-controlled trial. Eligible patients with primary advanced stage III or IV or first recurrent endometrial cancer were randomly assigned in a 1:1 ratio to receive either dostarlimab (500 mg) or placebo, plus carboplatin (area under the concentration-time curve, 5 mg per milliliter per minute) and paclitaxel (175 mg per square meter of body-surface area), every 3 weeks (six cycles), followed by dostarlimab (1000 mg) or placebo every 6 weeks for up to 3 years. The primary end points were progression-free survival as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, and overall survival. Safety was also assessed. RESULTS: Of the 494 patients who underwent randomization, 118 (23.9%) had mismatch repair-deficient (dMMR), microsatellite instability-high (MSI-H) tumors. In the dMMR-MSI-H population, estimated progression-free survival at 24 months was 61.4% (95% confidence interval [CI], 46.3 to 73.4) in the dostarlimab group and 15.7% (95% CI, 7.2 to 27.0) in the placebo group (hazard ratio for progression or death, 0.28; 95% CI, 0.16 to 0.50; P<0.001). In the overall population, progression-free survival at 24 months was 36.1% (95% CI, 29.3 to 42.9) in the dostarlimab group and 18.1% (95% CI, 13.0 to 23.9) in the placebo group (hazard ratio, 0.64; 95% CI, 0.51 to 0.80; P<0.001). Overall survival at 24 months was 71.3% (95% CI, 64.5 to 77.1) with dostarlimab and 56.0% (95% CI, 48.9 to 62.5) with placebo (hazard ratio for death, 0.64; 95% CI, 0.46 to 0.87). The most common adverse events that occurred or worsened during treatment were nausea (53.9% of the patients in the dostarlimab group and 45.9% of those in the placebo group), alopecia (53.5% and 50.0%), and fatigue (51.9% and 54.5%). Severe and serious adverse events were more frequent in the dostarlimab group than in the placebo group. CONCLUSIONS: Dostarlimab plus carboplatin-paclitaxel significantly increased progression-free survival among patients with primary advanced or recurrent endometrial cancer, with a substantial benefit in the dMMR-MSI-H population. (Funded by GSK; RUBY ClinicalTrials.gov number, NCT03981796.).

A Plain Language Summary of "Dostarlimab for primary advanced or recurrent endometrial cancer".

What is this summary about? Dostarlimab, also known by the brand name JEMPERLI, is a medicine that uses a patient's own immune system to treat endometrial cancer. Dostarlimab is a type of medicine called an immunotherapy. Immunotherapies help the immune system find and attack cancer cells. Dostarlimab stops cancer cells from being able to hide from the immune system, which allows the patient to have a boosted immune response against their cancer.The RUBY study is a phase 3 clinical study of primary advanced (cancer that has spread outside the uterus) or recurrent (cancer that has come back) endometrial cancer. A phase 3 clinical study looks at how well a new treatment works compared to the standard, or usual, treatment in a large patient population. The RUBY study is testing how well dostarlimab given with chemotherapy, followed by dostarlimab alone, works at delaying primary advanced or recurrent endometrial cancer from getting worse and preventing patients from dying, compared to chemotherapy given alone (the current standard treatment for primary advanced or recurrent endometrial cancer).What were the results? When dostarlimab was given with chemotherapy, this combination was found to delay primary advanced or recurrent endometrial cancer from getting worse and to prevent patients from dying, compared with chemotherapy given alone (without dostarlimab). Patients in the study who received dostarlimab with chemotherapy had a 36% lower risk of dying or having their cancer get worse.What do the results mean? The results from this study contributed to the approval of dostarlimab with chemotherapy as a new treatment option for patients with mismatch repair deficient/microsatellite instability-high primary advanced or recurrent endometrial cancer. As of the publication of this plain language summary of publication (PLSP), this combination of dostarlimab with chemotherapy has been approved in the United States of America, the United Kingdom, the European Union and Hong Kong.Clinical Trial Registration: NCT03981796 (RUBY).