A Study of Niraparib in Combination With Abiraterone Acetate and Prednisone Versus Abiraterone Acetate and Prednisone for Treatment of Participants With Metastatic Prostate Cancer

Brief Summary:
The purpose of this study is to evaluate the effectiveness of niraparib in combination with abiraterone acetate and prednisone (AA-P) compared to AA-P plus placebo.

Detailed Description:
This study will assess efficacy and safety of niraparib in combination with AA-P for the treatment of participants with metastatic prostate cancer. Niraparib is an orally available, highly selective poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor, with potent activity against PARP-1 and PARP-2 deoxyribonucleic acid (DNA)-repair polymerases. AA is a pro-drug of abiraterone and selectively inhibits the enzyme 17α-hydroxylase/C17,20-lyase (CYP17), which is found in the testes and adrenals, as well as in prostate tissues and tumors. In participants with metastatic prostate cancer, DNA-repair gene defects (DRD) are identified in approximately 15 percent (%) to 20% of tumors. The study will consist of 4 phases: a prescreening phase for biomarker evaluation only, a screening phase, a double-blind treatment phase, and a follow up phase. During the prescreening phase participants will be evaluated for DRD and then will be assigned to one of the 2 cohorts based on their biomarker status. Treatment will be administered daily and is planned to be continuous until disease progression, unacceptable toxicity, death, or the sponsor terminates the study. Efficacy, pharmacokinetics, biomarkers, participants reported outcomes and safety will be assessed. The total duration of study will be approximately up to 73 months.


Study Type: Interventional  (Clinical Trial)
Estimated Enrollment: 1000 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase 3 Randomized, Placebo-controlled, Double-blind Study of Niraparib in Combination With Abiraterone Acetate and Prednisone Versus Abiraterone Acetate and Prednisone in Subjects With Metastatic Prostate Cancer
Actual Study Start Date: January 25, 2019
Estimated Primary Completion Date: July 21, 2022
Estimated Study Completion Date: February 25, 2025

Arm:
- Experimental: Niraparib + Abiraterone Acetate-Prednisone (AA-P)
- Experimental: Placebo + AA-P