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

Open to females ages 18 years and up

Substudy 1

• Participants must be willing to provide an archival tumor tissue block or slides or must undergo a procedure to obtain a new tumor biopsy using a low-risk, medically routine procedure for immunohistochemistry (IHC) confirmation of FRα expression as defined by the central VENTANA FOLR1 (FOLR1-2.1) assay. Tumors must have FRα-expression in >= 50% of viable tumor cells with >= 2+ staining intensity.
• Participants must have an Eastern Cooperative Oncology Group performance status of 0 or 1.

• 1L participants must have a confirmed diagnosis of Federation of Gynecology and Obstetrics (FIGO) Stage III or IV high-grade serous epithelial ovarian, primary peritoneal, or fallopian tube cancer.

  2L participants must have platinum-sensitive high-grade serous epithelial ovarian, primary peritoneal, or fallopian tube cancer. Participants must have platinum-sensitive disease defined as radiographic progression greater than 183 days from the last dose of most recent platinumbased chemotherapy. Note: Progression should be calculated from the date of the last administered dose of platinum therapy to the date of the radiographic imaging showing progression.

• Participant has a local homologous recombination deficient (HRD) or breast cancer susceptibility gene (BRCA) test result available. Participants with BRCA wild-type will need to have a local HRD test result available.

Substudy 2

• Participants must be willing to provide an archival tumor tissue block or slides or must undergo a procedure to obtain a new tumor biopsy using a low-risk, medically routine procedure for immunohistochemistry (IHC) confirmation of FRα expression as defined by the central VENTANA FOLR1 (FOLR1-2.1) assay. Tumors must have FRα-expression in >= 50% of viable tumor cells with >= 2+ staining intensity.
• Participants must have an Eastern Cooperative Oncology Group performance status of 0 or 1.
• Participants must have a confirmed diagnosis of high-grade serous ovarian, primary peritoneal, or fallopian tube cancer.
• Participants must have relapsed after 1 or 2 prior lines of platinum-based chemotherapy.
• Participants must have platinum-sensitive disease defined as radiographic progression greater than 183 days from the last dose of platinum-based chemotherapy.
• Participants must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 (assessed by the investigator) at baseline.

Substudy 3

• Participants must be willing to provide an archival tumor tissue block or slides or must undergo a procedure to obtain a new tumor biopsy using a low-risk, medically routine procedure for immunohistochemistry (IHC) confirmation of FRα expression as defined by the central VENTANA FOLR1 (FOLR1-2.1) assay. Tumors must have FRα-expression in >= 50% of viable tumor cells with >= 2+ staining intensity.
• Participants must have an Eastern Cooperative Oncology Group performance status of 0 or 1.
• Participants must have a confirmed diagnosis of high-grade serous ovarian, primary peritoneal, or fallopian tube cancer.
• Participants must have relapsed after 1 or 2 prior lines of platinum-based chemotherapy.
• Participants must have platinum-sensitive disease defined as radiographic progression greater than 183 days from the last dose of platinum-based chemotherapy.
• Participants must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 (assessed by the investigator) at baseline.

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.
• Participants who receive an intervening dose of bevacizumab after the first day of their last triplet therapy cycle and before randomization.
• Participants who received prior treatment with mirvetuximab soravtansine (MIRV), any FRα-targeting agent, or Poly(ADP-ribose) polymerase inhibitor (PARPi).

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, PARPi) 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 same 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)
• Participants who received prior treatment with mirvetuximab soravtansine or other FRα-targeting agents.

Substudy 3

• 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, PARPi) 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 same 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)
• Participants who received prior treatment with mirvetuximab soravtansine or other FRα-targeting agents.