Study to Assess the Efficacy and Safety of Rina-S Plus Standard of Care Compared to Standard of Care for Maintenance Treatment of Participants With Recurrent Platinum-sensitive Ovarian Cancer After Second-line (2L) Platinum-based Doublet Chemotherapy

Key Inclusion Criteria: * Must have histologically or cytologically confirmed high-grade serous or endometrioid epithelial ovarian cancer (EOC), primary peritoneal cancer, or fallopian tube cancer. * Must have PSOC defined as progressive disease \> 6 months (ie, 183 days) from the last dose of primary (first-line \[1L\]) platinum therapy. * Participants with known breast cancer (BRCA)-mutated (somatic or germline) or homologous recombination deficiency (HRD)-positive ovarian cancer who achieved complete response (CR)/no clinical evidence of disease (NED) or partial response (PR) following 1L platinum-based chemotherapy regimen must have previously received PARPi maintenance therapy as part of their 1 L treatment. * Must have completed platinum-based chemotherapy in the 2L treatment for recurrent PSOC. * Must have received platinum-based chemotherapy in the 1L treatment and received platinum-based chemotherapy in the 2L treatment. * Must be randomized no later than 8 weeks from the last dose of the 2L platinum-based therapy. * Participants must have achieved a CR/NED, PR, or SD, as assessed by the investigator, following completion of 2L platinum-based chemotherapy. Key Exclusion Criteria: * Participants with clear cell, mucinous, or sarcomatous histology, mixed tumors containing any of the above histologies, or low-grade/borderline ovarian tumors * More than 2 prior lines of systemic therapy. * Progression while on or following 2L platinum-based regimen prior to randomization. * Participants who receive an intervening systemic anticancer treatment (excluding bevacizumab) after the last dose of 2L platinum-based chemotherapy and prior to randomization. Note: Other protocol-defined Inclusion and Exclusion criteria may apply.