Efficacy & Safety of Olvi-Vec and Platinum-doublet + Bevacizumab Compared to Physician's Choice of Chemotherapy and Bevacizumab in Platinum-Resistant/Refractory Ovarian Cancer (PRROC) (OnPrime, GOG-3076)

Inclusion Criteria:

• Histologically confirmed (from prior treatment) non-resectable ovarian, fallopiantube or primary peritoneal cancer.

• High-grade serous [including malignant mixed Mullerian tumor (MMMT) with metastasisthat contains high-grade epithelial carcinoma, FIGO grades 2 & 3 allowed],endometrioid, or clear-cell ovarian cancer.

• Performance status ECOG of 0 or 1.

• Life expectancy of at least 6 months.

• Received a minimum of 3 prior lines (including the 1st line) of systemic therapywith no maximal limit.

• Platinum-resistant or -refractory disease based on platinum-free interval (PFI) fromthe last dose of the most recent. platinum-based line of therapy (must have receiveda minimum of 2 doses of platinum in that line) to subsequent disease progressionbased on radiological assessment. Platinum-refractory: PFI of < 1 month (includingdisease progression while on platinum-based therapy). Platinum-resistant: PFI of 1-6months.

• Received prior bevacizumab (or biosimilar) treatment.

• No contraindication to receive carboplatin, cisplatin or bevacizumab (orbiosimilar).

• Have disease progression after last prior line of therapy based on radiologicalassessment prior to randomization.

• At least 1 measurable target lesion per RECIST 1.1 based on abdominal/pelvis imagingscan at screening.

• Evidence by CT and/or PET scans or physical exam of abdominal/pelvis region likelyhaving disease in the peritoneal cavity (i.e., peritoneal carcinomatosis).

• Adequate renal, hepatic, bone marrow function, adequate coagulation tests, adequateimmune function by lymphocyte count.

Exclusion Criteria:

• Tumors of mucinous, low-grade serous, squamous cell, small cell neuroendocrinesubtypes, MMMT tumors absent an epithelial component on recent biopsy, ornon-epithelial ovarian cancers (e.g., germ cell tumors, Sex-cord tumors).

• Bowel obstruction within last 3 months prior to screening.

• Active urinary tract infection, pneumonia, other systemic infections.

• Active gastrointestinal bleeding.

• Known current central nervous system (CNS) metastasis.

• Inflammatory diseases of the bowel.

• History of HIV infection.

• Active hepatitis B virus or hepatitis C virus within 4 weeks prior to study.

• History of thromboembolic event within the prior 3 months.

• Contraindications for intraperitoneal (IP) catheter placement: Bowel obstructionwith distended abdomen, rigid abdomen with bulky anterior wall carcinomatosis,abdominal wall hernia mesh that precludes laparoscopic entry to abdomen.

• Clinically significant cardiac disease at screening (New York Heart AssociationClass III/IV).

• Acute cerebrovascular event(s) such as cerebrovascular accident (CVA) or transientischemic attack (TIA) in previous 6 months.

• Oxygen saturation <90%.

• Received prior virus-based gene therapy or therapy with cytolytic virus of any type.

• Receiving concurrent antiviral agent.

• Prior malignancy of other histology active within previous 3 years except forlocally curable cancers apparently cured such as basal/squamous cell skin cancer,superficial bladder cancer, carcinoma in situ of cervix or breast, any other stageI/II local malignancies.

• Received chemotherapy, radiotherapy, other anti-cancer biologic therapies within 4weeks prior to planned treatment.

• Underwent surgery within 4 weeks, or have insufficient recovery fromsurgical-related trauma or wound healing, prior to first study treatment in eitherArm.

• Receiving immunosuppressive therapy or steroids (except acute concurrentcorticosteroid of no more than 20 mg per day for medical management withprednisolone equivalent.

• Symptomatic malignant ascites or pleural effusions defined as rapidly progressiveascites with abdominal distension and gastrointestinal dysfunction, pleuraleffusions with respiratory difficulties requiring frequent paracentesis > once every 14 days.

• Known hypersensitivity to gentamicin.