Primary Outcome Measures
Dose Limiting Toxicity (DLT) [Time Frame: Cycle 1 Days 1-28 (28 days from date of first dose of study treatment)] [Designated as safety issue: ]
Overall Response (OR) [Time Frame: From date of first dose of study treatment until the date of first documented disease progression or date of death from any cause, whichever comes first, assessed up to approximately 24 months] [Designated as safety issue: ]
Secondary Outcome Measures
Serum concentrations of avelumab [Time Frame: Day 1 Cycles 1-4, 6, 9, 12, 18, 24 and Day 15 Cycle 1] [Designated as safety issue: ]
Anti drug antibody (ADA) levels of avelumab [Time Frame: Day 1 Cycles 1-4, 6,9,12,18, 24 and Day 15 Cycle 1] [Designated as safety issue: ]
OR [Time Frame: From the start of treatment until disease progression/recurrence up to approximately 24 months] [Designated as safety issue: ]
PSA Tumor Marker [Time Frame: Baseline, Day1 of each cycle (each cycle is 28 days), and End of Treatment ( up to approximately 24 months)] [Designated as safety issue: ]
CA-125 Tumor Marker [Time Frame: Baseline, Day1 of each cycle (each cycle is 28 days), and End of Treatment (up to approximately 24 months)] [Designated as safety issue: ]
Biomarker PD-L1 [Time Frame: Baseline] [Designated as safety issue: ]
Genomic [Time Frame: Baseline] [Designated as safety issue: ]
Serum concentrations of avelumab [Time Frame: Day 1 Cycles 1-4, 6,9,12,18, 24 and Day 15 Cycle 1] [Designated as safety issue: ]
Plasma concentrations of talazoparib [Time Frame: Day 1 Cycles 1-4 and Day 15 Cycle 1] [Designated as safety issue: ]
Plasma concentration of talazoparib [Time Frame: Day 1 Cycles 1-4 and Day 15 Cycle 1] [Designated as safety issue: ]
Neutralizing antibodies (Nab) levels against avelumab. [Time Frame: Day 1 Cycles 1-4, 6, 9, 12, 18, 24 and Day 15 Cycle 1] [Designated as safety issue: ]
Time to Tumor Response (TTR) [Time Frame: Baseline up to approximately 24 months] [Designated as safety issue: ]
Duration of response (DR) [Time Frame: Baseline up to approximately 24 months] [Designated as safety issue: ]
Progression-Free Survival (PFS) [Time Frame: Baseline up to approximately 24 months] [Designated as safety issue: ]
Prostate-Specific Antigen (PSA) response [Time Frame: Baseline up to approximately 24 months] [Designated as safety issue: ]
Overall Survival (OS) [Time Frame: Baseline up to approximately 24 months] [Designated as safety issue: ]
Biomarker Tumor Mutational Burden [Time Frame: Baseline] [Designated as safety issue: ]