Study to Assess the Efficacy of Rina-S Compared to Treatment of Investigator's Choice in Participants With Platinum Resistant Ovarian Cancer

Key Inclusion Criteria:

• Participants must have histologically or cytologically confirmed high grade serousor endometrioid epithelial ovarian cancer, primary peritoneal cancer, or fallopiantube cancer.

• Participants may be enrolled regardless of FRα expression level.

• Participants must have received 1 to 4 prior lines of therapy. Participants musthave 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 andavailable as standard of care per institutional guidelines, unless theparticipant has a documented contraindication or unless the participant is noteligible for treatment with bevacizumab (or biosimilar) due toprecautions/intolerance

• Participants with known or suspected deleterious germline or somatic breastcancer gene (BRCA) mutations and who achieved a complete or partial response toplatinum-based chemotherapy must have been treated with a poly ADP-ribosepolymerase (PARP) inhibitor as maintenance treatment unless the participant isnot 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 andDrug Administration (FDA)-approved (or local equivalent) test, and

• The participant does not have a documented medical exception, includingchronic corneal disorders, history of corneal transplantation, or activeocular conditions requiring ongoing treatment/monitoring, such asuncontrolled glaucoma, wet age-related macular degeneration requiringintravitreal 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 havereceived at least 4 cycles of platinum therapy, and must have either had aresponse (CR or PR) or had non-measurable disease at the start of adjuvantplatinum-based therapy, and then progressed between > 91 days and ≤ 183 daysafter the date of the last dose of platinum.

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

Key Exclusion Criteria:

• Prior therapy with an antibody-drug conjugate containing a topoisomerase 1inhibitor.

• Have primary platinum-refractory disease, defined as ovarian cancer that did notrespond (CR or PR) to or progressed ≤ 91 days after the last dose of a first-lineplatinum-containing regimen.

• History of another malignancy within 3 years before the first dose of study drug, orany evidence of residual disease from a previously diagnosed malignancy. Exceptionsare malignancies with a negligible risk of metastasis or death (e.g., 5-year OS ≥90%), including, but not limited to, adequately treated carcinoma in situ of thecervix, non-melanoma skin carcinoma, ductal carcinoma in situ, or Stage I uterinecancer.

• Known active central nervous system metastases or carcinomatous meningitis.Participants with previously treated brain metastases may participate provided theyare clinically stable for at least 4 weeks prior to study entry after brainmetastasis treatment, they have no new or enlarging brain metastases, and are offcorticosteroids and anticonvulsants prescribed for symptoms associated with brainmetastases for at least 7 days prior to the first dose of study drug. Participantswith suspected brain metastases at screening should undergo a computed tomography (CT)/magnetic resonance imaging (MRI) of the brain prior to study entry.

• Hospitalization or clinical symptoms due to gastrointestinal obstruction within thepast 91 days or radiographic evidence of gastrointestinal obstruction at the time ofscreening. Enrollment of participants who currently require parenteral nutritionmust be discussed with the study medical monitor to determine eligibility.

• Ascites requiring frequent paracentesis (more often than approximately every 4weeks) for symptomatic management. Enrollment of participants with an indwellingperitoneal catheter must be discussed with the medical monitor to determineeligibility.

NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.