Presurgical Phase II Study of Talazoparib in Combination With Enzalutamide in Prostate Cancer

Primary Objective: •To evaluate the antitumor activity of presurgical talazoparib (PF-06944076) in combination with enzalutamide and androgen deprivation therapy (ADT) followed by surgery, in patients newly diagnosed with prostate cancer metastatic to lymph nodes (TxN1M0, TxNxM1a), as determined by the proportion of patients with undetectable prostate-specific antigen (PSA) 1 year after surgery. Secondary Objectives: * Analyze pathologic response in the primary tumor and metastatic lymph nodes to talazoparib in combination with enzalutamide and ADT in this population. * Analyze 5-year disease-free survival and 5-year metastasis-free survival after talazoparib in combination with enzalutamide and ADT followed by surgical consolidation in this population. * Evaluate the safety and tolerability of presurgical talazoparib in combination with enzalutamide and ADT in this population. * Evaluate induction of a conditional homologous recombination deficient (HRD) state after 2 mos. of ADT and enzalutamide treatment relative to clinical and pathological outcomes. Exploratory Objectives: * To evaluate predictive and/or prognostic genomic and transcriptomic biomarkers associated with response to treatment or disease progression. * To correlate data on intra-patient genomic heterogeneity from tumor biopsies and data from functional imaging with clinical benefit endpoints. * To study possible mechanisms of resistance to study treatments through the comparative analysis of candidate biomarkers from paired pre-treatment, on therapy, and post-therapy tumor tissue.