Talazoparib With Androgen Deprivation Therapy and Abiraterone for the Treatment of Castration Sensitive Prostate Cancer

PRIMARY OBJECTIVES: I. Increase the efficacy of first-line therapy for men with metastatic castration-sensitive prostate cancer by adding the PARP inhibitor talazoparib to standard therapy with androgen deprivation therapy (ADT) + abiraterone acetate (abiraterone). II. Study the efficacy of abiraterone and talazoparib in an ethnically diverse population. III. Evaluate whether androgen receptor genetic variation may identify a subpopulation of patients who benefit, even in the absence of homologous repair deficiency mutations. OUTLINE: Patients receive talazoparib orally (PO) once daily (QD), abiraterone acetate PO QD, and prednisone PO QD on days 1-28. Patients also receive androgen deprivation therapy consisting of degarelix subcutaneously (SC) on day 1; leuprolide acetate intramuscularly (IM) on day 1 and bicalutamide PO QD on days 1-28 of cycle 1 and then leuprolide acetate IM on day 1 of subsequent cycles; leuprolide acetate IM on day 1 and bicalutamide PO QD on days 1-28 of cycle 1 and then leuprolide acetate IM on day 1 of cycles 2, 5, 8, and 11; or goserelin acetate SC monthly or every 3 months. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days.