A Clinical Study of Raludotatug Deruxtecan in People With Ovarian Cancer (MK-5909-003).

Prior treatment

• Has any of the following within 6 months before allocation/randomization: cerebrovascular accident, transient ischemic attack, or other arterial thromboembolic event
• Has clinically severe pulmonary compromise resulting from intercurrent pulmonary illnesses including, but not limited to, any underlying pulmonary disorder, and any autoimmune, connective tissue, or inflammatory disorders with potential pulmonary involvement, or prior pneumonectomy
• Has received prior treatment with cadherin-6-targeted agents
• Has received prior systemic anticancer therapy including investigational agents within 4 weeks or 5 half-lives (whichever is shorter) before allocation
• Has received prior radiotherapy within 2 weeks of the start of study intervention, or has radiation-related toxicities, requiring corticosteroids
• Receives chronic steroid treatment
• Has any history of interstitial lung disease (ILD)/pneumonitis irrespective of prior steroid use, current ILD, or suspected ILD, or ILD that cannot be ruled out by imaging at screening

Other illness

• Has uncontrolled or significant cardiovascular disease
• Has known additional malignancy that is progressing or has required active treatment within the past 3 years
• Has active infection requiring systemic therapy
• HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease

Other

• Has ≥Grade 2 peripheral neuropathy
• Has known active CNS metastases and/or carcinomatous meningitis

• Has pathologically documented diagnosis of high-grade serous or high-grade endometrioid epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer
• Participants in Part 1 cohorts and Part 2 Cohort A-2 Arms 1, 2, and 3, Cohort B-2, and Cohort C-2 Arm 3: Has measurable disease per Response Evaluation Criteria In Solid Tumors 1.1
• Participants in Cohort A-1 Arms 2 and 3: Has relapsed disease after 1 to 3 prior lines of therapy and radiographic evidence of disease progression ≥6 months (≥180 days) after the last dose of platinum-based therapy (ie, platinum-sensitive disease)
• Participants in Cohort B-1 and Cohort B-2: Has relapsed disease after 1 to 3 prior lines of therapy and radiographic evidence of disease progression \<6 months (\<180 days) after the last dose of platinum-based therapy (ie, platinum-resistant disease). Participants must have received no more than 1 prior bevacizumab-containing systemic treatment regimen
• Participants in Cohort B-1, Cohort B-2, Cohort C-2 Arm 3, Cohort E-1 and if administering bevacizumab is planned in Cohort D or Cohort A-2 Arms 1, 2, or 3: Is a candidate for bevacizumab treatment
• Has provided tumor tissue for biomarker research (all cohorts)
• Has an Eastern Cooperative Oncology Group performance status of 0 to 1
• Participants in Cohort C-1, Cohort C-2 Arm 3, Cohort D, and Cohort E-1: Has relapsed disease after 1 prior line of therapy, radiographic evidence of disease progression ≥6 months (≥180 days) after the last dose of platinum-based therapy (ie, platinum-sensitive disease) and progressed during prior treatment with poly-ADP ribose polymerase inhibitor (PARPi) in the first-line setting
• Participants in Cohort A-2 Arms 1, 2, and 3: Has relapsed disease after 1 prior line of therapy and radiographic evidence of disease progression ≥6 months (≥180 days) after the last dose of platinum-based therapy (ie, platinum-sensitive disease)
• Participants in Cohort C-2 Arms 1 and 2: Has a new, histologically confirmed diagnosis of International Federation of Gynecology and Obstetrics Stage III or Stage IV epithelial ovarian cancer (high-grade serous or high-grade endometrioid), fallopian tube cancer, or primary peritoneal cancer that is non-homologous recombination deficiency-positive
• Participants in Cohort C-2 Arms 1 and 2: According to the investigator's assessment, PARPi first-line maintenance treatment for non- homologous recombination deficiency (HRD)-positive disease is not the preferred option for the participant
• Participants in Cohort C-2 Arms 1 and 2: According to the investigator's assessment, bevacizumab treatment for non-HRD-positive disease is not the preferred option for the participant