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.