Key Inclusion Criteria:

          1. Has histologically or cytologically confirmed diagnosis of advanced epithelial ovarian
             cancer (except carcinosarcoma), primary peritoneal, or fallopian tube cancer that has
             received at least 1 line of platinum-based systemic therapy as defined in the protocol

          2. In dose escalation, patients will provide either newly obtained biopsy (newly obtained
             biopsies at screening are required unless medically inappropriate and discussed with
             medical monitor. If fresh biopsies are not appropriate, and after sponsor approval,
             archived tumor tissue in dose escalation is acceptable. In dose expansion, patients
             will provide a fresh tumor biopsy in screening and on treatment. Hence, in expansion
             cohorts, only patients who (in the opinion of the investigator) have accessible
             lesions that can be biopsied without significant risk to the patient are eligible.

          3. Expansion cohorts only: Has at least 1 lesion that is measurable by RECIST 1.1. Tumor
             lesions in a previously irradiated area are considered measurable if progression has
             been demonstrated in such lesions after radiation.

          4. Has a serum CA-125 level ≥2x ULN (in screening)

          5. Has adequate organ and bone marrow function as defined in the protocol

          6. Has a life expectancy of at least 3 months

        Key Exclusion Criteria:

          1. Has participated in a study of an investigational agent (except biologics and/or
             immunotherapy) or an investigational device within 4 weeks of first dose of study drug

          2. Has received treatment with an approved systemic therapy (except biologics and/or
             immunotherapy) within 3 weeks or has not yet recovered as defined in the protocol

          3. Prior anti-cancer immunotherapy as defined in the protocol

          4. Has received radiation therapy or major surgery within 14 days of first administration
             of study drug as defined in the protocol

          5. Has had another malignancy within the last 5 years that is progressing, requires
             active treatment, or has a high likelihood of recurrence as defined in the protocol

          6. Prior treatment with a MUC16-targeted therapy

          7. Expansion cohorts only: More than 3 prior lines of cytotoxic chemotherapy for
             platinum-experienced and/or intolerant disease

          8. Has any condition that requires ongoing/continuous corticosteroid therapy as defined
             in the protocol within 1 week prior to the first dose of study drug

          9. Has ongoing or recent (within 5 years) evidence of significant autoimmune disease that
             required treatment with systemic immunosuppressive treatments as defined in the
             protocol

         10. Has untreated or active primary brain tumor, CNS metastases, leptomeningeal disease,
             or spinal cord compression as defined in the protocol

         11. Has encephalitis, meningitis, organic brain disease (eg, Parkinson's disease) or
             uncontrolled seizures in the year prior to first dose of study drug

         12. Has history of clinically significant cardiovascular disease as defined in the
             protocol

        Note: Other protocol-defined Inclusion/Exclusion criteria apply