A Study to Assess Adverse Events and Change in Disease Activity of Multiple Treatment Combinations With Intravenous Mirvetuximab Soravtansine in Adult Participants With Ovarian Cancer

Inclusion Criteria: * Substudy 1 and 2: Confirmed high or medium folate receptor alpha (FRa) expression by Ventana folate receptor 1 (FOLR1) Assay. * Substudy 1 and 2: Participants must have an Eastern Cooperative Oncology Group performance status of 0 or 1. * Substudy 1: Participants must have a confirmed diagnosis of Federation of Gynecology and Obstetrics (FIGO) Stage III or IV high-grade serous ovarian, primary peritoneal, or fallopian tube cancer. * Substudy 1: Tumor must be confirmed HRD test negative (HRP), determined by a local homologous recombination deficient (HRD) test. * Substudy 2: Participants must have a confirmed diagnosis of high-grade serous ovarian, primary peritoneal, or fallopian tube cancer. * Substudy 2: Participants must have relapsed after 1 or 2 prior lines of platinum-based chemotherapy. * Substudy 2: Participants must have platinum-sensitive disease defined as radiographic progression greater than 6 months from the last dose of platinum-based chemotherapy. * Substudy 2: Participants must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 (assessed by the investigator) at baseline. Exclusion Criteria: * Substudy 1: Participants with progressive disease (PD) while on triplet therapy or after the first day of their last triplet therapy cycle and before randomization. * Substudy 1: Participants who receive an intervening dose of bevacizumab after the first day of their last triplet therapy cycle and before randomization. * Substudy 1: Participants who received prior treatment with mirvetuximab soravtansine, any FRα-targeting agent, or any investigational agent. * Substudy 2: More than 2 prior lines of chemotherapy. Lines of prior anticancer therapy are counted with the following considerations: * Neoadjuvant +/- adjuvant therapies are considered 1 line of therapy if the neoadjuvant and adjuvant correspond to 1 fully predefined regimen; otherwise, they are counted as 2 prior regimens. * Maintenance therapy (e.g., bevacizumab, PARP inhibitor) will be considered part of the preceding line of therapy (i.e., not counted independently). * If a chemotherapeutic agent in a regimen is substituted with another during a course of treatment due to toxicity, it will be considered part of the proceeding line of therapy * Prior hormonal therapy will not be counted as a separate line of chemotherapy (it will be counted as part of the prior systemic therapy regimen) * Substudy 2: Participants who received prior treatment with mirvetuximab soravtansine or other FRα-targeting agents.