Sponsor made a business decision to discontinue the study due to low accrual.

This is an open label Phase 2, 2-stage, 2-cohort study to evaluate rucaparib in combination with nivolumab in patients with high-grade serous or endometroid ovarian cancer.

Patients entering the following cohorts must have BRCA mutational status confirmed by a central lab:

• Cohort A1: No BRCA mutation in tumor; high level of LOH (loss of heterozygosity)
• Cohort A2: BRCA mutation in tumor

General Inclusion Criteria:

• ≥ 18 years of age
• Adequate organ function
• Life expectancy ≥ 16 weeks
• Women of childbearing potential must have a negative serum pregnancy test
• High-grade serous or endometrioid epithelial ovarian, fallopian tube, or primary peritoneal cancer
• Received 1 or 2 prior regimens, including ≥ 1 prior platinum-based therapy and have platinum-sensitive disease
• Relapsed/progressive disease (confirmed by radiologic assessment)
• Willing and able to have a biopsy of tumor at screening and after 4 weeks of treatment.
• Measurable disease (RECIST v1.1)- Cohort A1 only
• ECOG performance status of 0 to 1

General Exclusion Criteria

• Active second malignancy
• Central nervous system brain metastases
• Evidence of interstitial lung disease, active pneumonitis, myocarditis, or history of myocarditis.
• Active, known or suspected autoimmune disease (eg, autoimmune hepatitis).
• Condition requiring systemic treatment with either corticosteroids
• Prior treatment with a PARP inhibitor or immune checkpoint inhibitor.
• Non-epithelial tumors (pure sarcomas) or ovarian tumors with low malignant potential (ie, borderline tumors) or mucinous tumors. Mixed Mullerian tumors/carcinosarcomas are allowed.

Sponsor's agreements with investigators require proposed public disclosures of trial results to be submitted to Sponsor for review prior to publication. Sponsor may request deletion of confidential information or a delay in publication to address intellectual property concerns, but Sponsor may not suppress publication of the trial results indefinitely. Sponsor may request delay of a single-center publication until after the release of a multi-site publication or an agreed upon period of time.