• Participants must have histologically or cytologically confirmed high grade serous or endometrioid epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer.

• Participants may be enrolled regardless of FRα expression level.

• Participants must have received 1 to 4 prior lines of therapy. Participants must have progressed radiographically on or after their most recent line of therapy.

• Participants must have received prior treatment with the following therapies:

‣ Platinum chemotherapy

⁃ Prior bevacizumab (or biosimilar) treatment is required, if labeled and available as standard of care per institutional guidelines, unless the participant has a documented contraindication or unless the participant is not eligible for treatment with bevacizumab (or biosimilar) due to precautions/intolerance

⁃ Participants with known or suspected deleterious germline or somatic breast cancer gene (BRCA) mutations and who achieved a complete or partial response to platinum-based chemotherapy must have been treated with a poly ADP-ribose polymerase (PARP) inhibitor as maintenance treatment unless the participant is not eligible for treatment with PARP inhibitor

⁃ Mirvetuximab soravtansine, if:

• Mirvetuximab soravtansine is available in the enrollment region, and

∙ The participant is eligible based on positive FRα expression per Food and Drug Administration (FDA)-approved (or local equivalent) test, and

∙ The participant does not have a documented medical exception, including chronic corneal disorders, history of corneal transplantation, or active ocular conditions requiring ongoing treatment/monitoring, such as uncontrolled glaucoma, wet age-related macular degeneration requiring intravitreal injections, active diabetic retinopathy with macular edema, macular degeneration, presence of papilledema, and /or monocular vision.

• Participants must have platinum-resistant disease:

‣ Participants who have only had 1 line of platinum-based therapy must have received at least 4 cycles of platinum therapy, and must have either had a response (CR or PR) or had non-measurable disease at the start of adjuvant platinum-based therapy, and then progressed between \> 91 days and ≤ 183 days after the date of the last dose of platinum.

⁃ Participants who have received 2 to 4 lines of platinum-based therapy must have progressed on or within 183 days after the date of the last dose of platinum.