A Study of Niraparib in Combination With Abiraterone Acetate and Prednisone Versus Abiraterone Acetate and Prednisone for the Treatment of Participants With Deleterious Germline or Somatic Homologous Recombination Repair (HRR) Gene-MutatedProstatic Neoplasms (mCSPC)

Condition(s) studied

Investigational drug(s) / intervention(s)

Niraparib+ Abiraterone acetate fixed dose combination (FDC): Participants will receive a FDC of Niraparib 200 mg + AA 1000 mg once daily.

Abiraterone acetate (AA): Participants will receive AA 1000 mg once daily.

Prednisone: Participants will receive prednisone 5 mg once daily.

Placebo FDC: Participants will receive matching placebo for Niraparib +AA FDC once daily.

Placebo AA: Participants will receive matching placebo for AA once daily.

Study summary

The purpose of the study is to determine if the combination of niraparib with Abiraterone Acetate (AA) plus prednisone compared with AA plus prednisone in participants with deleterious germline or somatic Homologous Recombination Repair (HRR) gene-mutated Metastatic Castration-Sensitive Prostate Cancer (mCSPC) provides superior efficacy in improving radiographic progression-free survival (rPFS).

Eligibility

Primary outcome measure(s)

• Breast Cancer Gene (BRCA) Subgroup: Radiographic Progression-free Survival (rPFS) Assessed by Investigator — From date of randomization (Day -3 to Day 1) up to approximately 49 months
  rPFS: time interval from date of randomization to first date of radiographic progression as assessed by investigator or death due to any cause, whichever occurred first. rPFS was determined by: (1) progression of soft tissue lesions measured by computerized tomography (CT) or magnetic resonance imaging (MRI) per response evaluation criteria in solid tumors (RECIST) 1.1; (2) progression of bone lesions observed by bone scan per prostate cancer working group 3 (PCWG3) criteria: bone progression was confirmed by subsequent scan greater than or equal to (\>=) 6 weeks later. Week 8 scan was baseline to which all subsequent scans were compared to determine progression. A confirmatory scan with \>=2 new lesions indicated progression; A confirmatory scan not showing \>=2 new lesions means no progression. If Week 8 scan shows \<2 new bone lesions compared to baseline, first scan with \>=2 new lesions compared to Week 8 scan indicated progression, when confirmed by a subsequent scan \>=6 weeks later.
• HRR Effector Subgroup: Radiographic Progression-free Survival (rPFS) Assessed by Investigator — From date of randomization (Day -3 to Day 1) up to approximately 49 months
  rPFS: time interval from date of randomization to first date of radiographic progression as assessed by investigator or death due to any cause, whichever occurred first. rPFS was determined by: (1) progression of soft tissue lesions measured by CT or MRI per RECIST 1.1; (2) progression of bone lesions observed by bone scan per PCWG3 criteria: bone progression was confirmed by subsequent scan \>= 6 weeks later. Week 8 scan was baseline to which all subsequent scans were compared to determine progression. A confirmatory scan with \>=2 new lesions indicated progression; A confirmatory scan not showing \>=2 new lesions means no progression. If Week 8 scan shows \<2 new bone lesions compared to baseline, first scan with \>=2 new lesions compared to Week 8 scan indicated progression, when confirmed by a subsequent scan \>=6 weeks later.
• All HRR: Radiographic Progression-free Survival (rPFS) Assessed by Investigator — From date of randomization (Day -3 to Day 1) up to approximately 49 months
  rPFS: time interval from date of randomization to first date of radiographic progression as assessed by investigator or death due to any cause, whichever occurred first. rPFS was determined by: (1) progression of soft tissue lesions measured by CT or MRI per RECIST 1.1; (2) progression of bone lesions observed by bone scan per PCWG3 criteria: bone progression was confirmed by subsequent scan \>= 6 weeks later. Week 8 scan was baseline to which all subsequent scans were compared to determine progression. A confirmatory scan with \>=2 new lesions indicated progression; A confirmatory scan not showing \>=2 new lesions means no progression. If Week 8 scan shows \<2 new bone lesions compared to baseline, first scan with \>=2 new lesions compared to Week 8 scan indicated progression, when confirmed by a subsequent scan \>=6 weeks later.

Trial sites (387)

+ 347 more sites — see the full list on the official registry below.