Sac-TMT for Advanced Ovarian Cancer

The main inclusion criteria include but are not limited to the following: * Has diagnosis of FIGO 2014 Stage III or Stage IV, histologically confirmed epithelial ovarian, primary peritoneal, or fallopian tube carcinoma with one of the following histologies: high-grade serous, high-grade endometrioid, clear cell carcinoma, or malignant mixed Müllerian tumour with a high-grade serous component. Tumors reported as Grade 2 may be enrolled only if predominately (\>50%) Grade 3 features are present. * Has completed primary debulking surgery or interval debulking surgery. * Has completed first-line (1L) platinum-based chemotherapy, with a response of stable disease, partial response, complete response or no evidence of disease per protocol. * Has provided tumor tissue that is not previously irradiated. * Has well-controlled human immunodeficiency virus (HIV) on antiretroviral therapy if diagnosed with HIV * Has undetectable hepatitis B virus (HBV) viral load and received HBV antiviral therapy if hepatitis B surface antigen (HBsAg)-positive. * Has undetectable hepatitis C virus (HCV) viral load if has a history of HCV infection. The main exclusion criteria include but are not limited to the following: * Has nonepithelial cancers, low-grade serous tumors, low-grade endometrioid tumors, borderline tumors mucinous, seromucinous that is predominantly mucinous, malignant Brenner's tumor, and undifferentiated carcinoma. * Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. * Has a history of severe eye disease. * Has active inflammatory bowel disease requiring immunosuppressive medication or a previous history of inflammatory bowel disease. * Has uncontrolled, significant cardiovascular disease or cerebrovascular disease. * Has a history of (noninfectious) pneumonitis/interstitial lung disease (ILD), which required steroids, has current pneumonitis/ILD, or has suspected ILD, or pneumonitis that cannot be ruled out by standard diagnostic assessments at Screening. * Received prior systemic anticancer therapy, with the exception of the first-line platinum-based chemotherapy required by the inclusion criteria. * Had a live or live-attenuated vaccine within 30 days of randomization. * Has a known additional malignancy that is progressing or required active treatment within the past 3 years. * Has active infection requiring systemic therapy. * Has concurrent and active HBV and HCV infections. * Has HIV infection and a history of Kaposi's sarcoma and/or multicentric Castleman's disease. * Has not recovered from major surgery or has ongoing surgical complications. * Has a homologous recombination deficiency (HRD)-positive, unknown, or inconclusive tumor status as determined by the central laboratory. * Active or ongoing stomatitis of any grade.