This study is testing new treatments for advanced or recurrent endometrial cancer, a type of cancer that starts in the lining of the uterus. The study compares two groups receiving different combinations of drugs: Trastuzumab Deruxtecan (T-DXd) with either Rilvegostomig or Pembrolizumab, against another group receiving chemotherapy and Pembrolizumab. Trastuzumab Deruxtecan is a type of drug that targets cancer cells, while Pembrolizumab is an immune therapy that helps the body fight cancer. **Key Points:** - **Duration & Visits:** The study will require multiple visits over an extended period. - **Eligibility:** Participants must be 18 or older with specific types of endometrial cancer and meet certain health criteria. - **Risks & Benefits:** Participation involves potential benefits from new treatments but also risks from side effects. To be part of this study, you need to have not received certain previous treatments and must pass health checks. The study aims to see if these new drug combinations help stop cancer progression longer than the usual chemotherapy. Note: Discuss with your doctor to see if joining this study is right for you.