A Study of Dostarlimab in Combination With Carboplatin-paclitaxel in Japanese Participants With Primary Advanced or Recurrent Endometrial Cancer

Prior treatment

• Participant has a concomitant malignancy, or participant has a prior non-endometrial invasive malignancy who has been disease-free for \<3 years or who received any active treatment in the last 3 years for that malignancy. Non-melanoma skin cancer is allowed.
• Participant has received prior anticancer therapy (chemotherapy, targeted therapies, hormonal therapy, radiotherapy, or immunotherapy) within 21 days or \<5 times the half-life of the most recent therapy prior to the first dose of study intervention, whichever is shorter.
• Participant has received any live vaccine within 30 days of the first dose of study intervention. Vaccination against coronavirus disease 2019 (COVID-19) using vaccines that are authorized via the appropriate regulatory mechanisms are not exclusionary.
• Participant is currently participating and receiving study intervention or has participated in a study of an investigational agent and received study intervention or used an investigational device within 4 weeks of the first dose of treatment.

Other illness

• Participant has any medical history of interstitial lung disease or pneumonitis.
• Participant has cirrhosis or current unstable liver or biliary disease.
• Participant has HBsAg positive, or HCV RNA positive.
• Participant is known HIV infection.

Lab values

• Participant has received prior therapy with an anti- Programmed death protein 1 (PD-1), anti- Programmed death ligand 1 (PD-L1), anti- Programmed death ligand 2 (PD-L2), or anti- Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) agent.

Other

• Participant has known uncontrolled central nervous system metastases, carcinomatosis meningitis, or both.
• Participant has a diagnosis of immunodeficiency.
• Participant has not recovered adequately from AEs.
• Participant with contraindication to carboplatin and paclitaxel.

• Participant has histologically or cytologically proven endometrial cancer with recurrent or advanced disease.
• Participant has molecular subtype of defective mismatch repair/microsatellite instability high (dMMR/MSI-H) or mismatch repair proficient/microsatellite stable (MMRp/MSS) determined.
• Participant must have primary Stage III or Stage IV disease or first recurrent endometrial cancer with a low potential for cure by radiation therapy or surgery alone or in combination, and presence of at least one measurable lesion per RECIST 1.1 based on Investigator's assessment.
• Participant is not pregnant or breastfeeding and agrees to use a highly effective contraceptive method during the study period if a woman of childbearing potential (WOCBP).
• Participant has an Eastern Cooperative Oncology Group Performance status (ECOG PS) of 0 or 1.
• Participant has adequate organ function, as assessed by hematologic, renal, hepatic and coagulation parameters.