Safety and Efficacy of Retifanlimab (INCMGA00012) Alone or in Combination With Other Therapies in Participants With Advanced or Metastatic Endometrial Cancer Who Have Progressed on or After Platinum-based Chemotherapy.

Inclusion Criteria:

• Ability to comprehend and willingness to sign a written ICF for the study. Note forGermany: This excludes individuals who are housed in an institution due to officialor court order Women 18 years of age or older (or as applicable per local countryrequirements).

• Histologically confirmed diagnosis of advanced or metastatic endometrial cancer withdisease progression on or after treatment with at least 1 platinum-containingregimen for advanced or metastatic disease.

• Groups A, B, and E: Have not been previously treated with a PD-(L)1 inhibitor.

• Group A only: Tumor tissue tested as MSI-High

• Group B only: Tumor tissue tested as deficient MMR or an ultra-mutated POLE tumor.

• Group D only: Tumor tissue tested as having an FGFR 1,2,3 mutation or alterationcharacterized as per protocol.

• Group E: Tumor tissue tested as MSS and PD-L1 positive.

• Group F: Radiological evidence of disease progression on or after prior PD (L)1therapy and Tumor tissue tested as MSI-H

• Must have at least 1 measurable tumor lesion per RECIST v1.1.

• Willing to provide tumor tissue sample (fresh or archived).

• ECOG performance status 0 to 1.

• Willingness to avoid pregnancy.

Exclusion Criteria:

• Group A, B and E only: Histologically confirmed diagnosis of carcinosarcoma of theuterus.

• Histologically confirmed diagnosis of sarcoma of the uterus.

• Has disease eligible for potentially curative treatment.

• Receipt of anticancer therapy within 28 days of the first administration of studytreatment, with the exception of localized radiotherapy.

• Toxicity of prior therapy that has not recovered to ≤ Grade 1 or baseline unlessapproved by the medical monitor.

• Groups C, D and F (combinations): limiting immune-related toxicity during priorcheckpoint inhibitor therapy.

• Group F only: Previous treatment with LAG-# or TIM-3 therapy or lenvatinib; multiplemetastases that achieved mixed tumor response to prior anti-PD-(L)1 therapy

• Has an active autoimmune disease requiring systemic immunosuppression withcorticosteroids (> 10 mg/day of prednisone or equivalent) or immunosuppressive drugswithin 14 days before the first dose of study treatment.

• Receiving chronic systemic steroids (> 10 mg/day of prednisone or equivalent):

• Known active CNS metastases and/or carcinomatous meningitis.

• Has known active hepatitis B or C.

• Has received a live vaccine within 28 days of the planned start of study treatment.

• Evidence of interstitial lung disease or active, noninfectious pneumonitis.

• Participants who are known to be HIV-positive with some protocol exceptions.