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

Inclusion Criteria:

1. Participant has histologically or cytologically proven endometrial cancer withrecurrent or advanced disease.

2. Participant has molecular subtype of defective mismatch repair/microsatelliteinstability high (dMMR/MSI-H) or mismatch repair proficient/microsatellite stable (MMRp/MSS) determined.

3. Participant must have primary Stage III or Stage IV disease or first recurrentendometrial cancer with a low potential for cure by radiation therapy or surgeryalone or in combination, and presence of at least one measurable lesion per RECIST 1.1 based on Investigator's assessment.

4. Participant is not pregnant or breastfeeding and agrees to use a highly effectivecontraceptive method during the study period if a woman of childbearing potential (WOCBP).

5. Participant has an Eastern Cooperative Oncology Group Performance status (ECOG PS)of 0 or 1.

6. Participant has adequate organ function, as assessed by hematologic, renal, hepaticand coagulation parameters.

Exclusion Criteria:

1. Participant has a concomitant malignancy, or participant has a prior non-endometrialinvasive malignancy who has been disease-free for <3 years or who received anyactive treatment in the last 3 years for that malignancy. Non-melanoma skin canceris allowed.

2. Participant has any medical history of interstitial lung disease or pneumonitis.

3. Participant has cirrhosis or current unstable liver or biliary disease.

4. Participant has known uncontrolled central nervous system metastases, carcinomatosismeningitis, or both.

5. Participant has a diagnosis of immunodeficiency.

6. 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.

7. Participant has not recovered adequately from AEs.

8. Participant has received prior anticancer therapy (chemotherapy, targeted therapies,hormonal therapy, radiotherapy, or immunotherapy) within 21 days or <5 times thehalf-life of the most recent therapy prior to the first dose of study intervention,whichever is shorter.

9. Participant has received any live vaccine within 30 days of the first dose of studyintervention. Vaccination against coronavirus disease 2019 (COVID-19) using vaccinesthat are authorized via the appropriate regulatory mechanisms are not exclusionary.

10. Participant has HBsAg positive, or HCV RNA positive.

11. Participant is known HIV infection.

12. Participant is currently participating and receiving study intervention or hasparticipated in a study of an investigational agent and received study interventionor used an investigational device within 4 weeks of the first dose of treatment.

13. Participant with contraindication to carboplatin and paclitaxel.