A Phase 1 interventional study of Niraparib and Abiraterone Acetate (AA) in Prostatic Neoplasms, sponsored by Janssen Research & Development, LLC. Active, not recruiting at 16 sites in 11 countries. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by Janssen Research & Development, LLC · Phase 1, Interventional, and Other
The purpose of this study is to determine the relative bioavailability (rBA; Period 1) and bioequivalence (BE; Period 2 and 3) of various strengths and formulations of niraparib and abiraterone acetate (AA) at steady state under modified fasted conditions in participants with metastatic castration-resistant prostate cancer (mCRPC).
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 which selectively inhibits the enzyme 17 alpha-hydroxylase/C17,20-lyase (CYP17), that is found in the testes and adrenals (leading to systemic inhibition of testosterone production), as well as in prostate tissues and tumors. The rationale of the study is to investigate the various strengths and formulations of niraparib and AA plus prednisone or prednisolone (P) in metastatic castration resistant prostate cancer (mCRPC) participants with and without homologous recombination repair (HRR) gene alterations. In participants with metastatic prostate cancer, DNA-repair anomalies are found in approximately 15 percent (%) to 20% of tumors. This study consists 4 periods: screening phase (up to 21 days); treatment phase (up to 22 days); extension and long-term extension phases (from day 23 until discontinuation); and post-treatment follow up phase (end of treatment [EoT] visit within 30 days after the last dose of study treatment). Total duration of study is up to 1.4 years. Efficacy, safety, pharmacokinetics (PK), and biomarkers will be assessed at specified time points during this study. Participants safety will be monitored throughout the study.
6,370 studies on the registry are indexed under Prostatic Neoplasms; 1,400 are open to participants now.
This study's enrollment of 136 is above the median of 58 across 4,822 interventional studies indexed under Prostatic Neoplasms.
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Exclusion Criteria:
Participants will receive single doses of niraparib and abiraterone acetate (AA) using niraparib Formulation 1 as Treatment A in Treatment Period 1, followed by multiple doses of niraparib and AA using niraparib Formulation 2 as Treatment B in Treatment Period 2, followed by multiple doses of niraparib and AA using niraparib Formulation 4 as Treatment D in Treatment Period 3. From Period 2 onwards and during Extension and Long-term Extension Phases, all participants will continue to receive treatment with niraparib and AA-prednisone (AAP) or AAP alone.
Drug: Niraparib · Drug: Abiraterone Acetate (AA) · Drug: Prednisone
Participants will receive Treatment A in Treatment Period 1 followed by Treatment D in Treatment Period 2, followed by Treatment B in Treatment Period 3. From Period 2 onwards and during Extension and Long-term Extension Phases, all participants will continue to receive treatment with niraparib and AAP or AAP alone.
Drug: Niraparib · Drug: Abiraterone Acetate (AA) · Drug: Prednisone
Participants will receive single doses of niraparib and AA using niraparib Formulation 3 as Treatment C in Treatment Period 1, followed by Treatment B in Treatment Period 2, followed by Treatment D in Treatment Period 3. From Period 2 onwards and during Extension and Long-term Extension Phases, all participants will continue to receive treatment with niraparib and AAP or AAP alone.
Drug: Niraparib · Drug: Abiraterone Acetate (AA) · Drug: Prednisone
Participants will receive Treatment C in Treatment Period 1, followed by Treatment D in Treatment Period 2, followed by Treatment B in Treatment Period 3. From Period 2 onwards and during Extension and Long-term Extension Phases, all participants will continue to receive treatment with niraparib and AAP or AAP alone.
Drug: Niraparib · Drug: Abiraterone Acetate (AA) · Drug: Prednisone
Niraparib will be administered orally.
Abiraterone Acetate will be administered orally.
Prednisone will be administered orally.
Maximum Observed Analyte Concentration at Steady State (Cmax,ss) of Niraparib and Abiraterone Acetate (AA) [Period 2 and Period 3]
Cmax,ss is defined as maximum observed analyte concentration at steady state.
Time frame: Predose, up to 10 hour post dose
Area Under the Plasma Concentration-time Curve from Time Zero to 24 Hours at Steady State (AUC [0-24h],ss) of Niraparib and AA (Period 2 and Period 3)
AUC (0-24h),ss is defined as area under the plasma concentration-time curve from time zero to 24 hours at steady state.
Time frame: Predose, up to 24 hours post dose
Ratio of Individual Cmax,ss Values Between Test and Reference Treatment (Period 2 and Period 3)
Ratio of individual Cmax,ss values between test and reference treatment will be assessed.
Time frame: Predose, up to 10 hours post dose
Ratio of individual AUC (0-24h),ss Values Between Test and Reference Treatment (Period 2 and Period 3)
Ratio of individual AUC (0-24h),ss values between test and reference treatment will be assessed.
Time frame: Predose, up to 24 hours post dose
Maximum Observed Analyte Concentration at (Cmax) of Niraparib and AA (Period 1)
Cmax is defined as maximum observed analyte concentration.
Time frame: Predose, up to 72 hours post dose
Area Under the Plasma Concentration-time Curve from Time Zero to 72 Hours (AUC [0-72h]) of Niraparib and AA (Period 1)
AUC (0-72h) is defined as area under the plasma concentration-time curve from time zero to 72 hours post dosing.
Time frame: Predose, up to 72 hours post dose
Ratio of individual AUC (0-72h) Values Between Test and Reference Treatment (Period 1)
Ratio of individual AUC (0-72h) values between test and reference treatment will be assessed.
Time frame: Predose, up to 72 hours post dose
Serum Testosterone Level
Serum testosterone level will be assessed.
Time frame: Predose on Day -7, Day 11, Day 12 and Day 23
Number of Participants with Adverse Events (AEs) as a Measure of Safety and Tolerability
An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study.
Time frame: From study start until study completion (up to 3.1 years)
Number of Participants with AEs by Severity
Severity will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 5.0. Severity scale ranges from Grade 1 (Mild) to Grade 5 (Death). Grade 1= Mild, Grade 2= Moderate, Grade 3= Severe, Grade 4= Life-threatening and Grade 5= Death.
Time frame: From study start until study completion (up to 3.1 years)
Number of Participants with Clinical Laboratory Abnormalities
Number of participants with clinical laboratory abnormalities including hematology, serum chemistry and urinalysis will be reported.
Time frame: From study start until study completion (up to 3.1 years)
Plan to share: Yes — The data sharing policy of the Janssen Pharmaceutical Companies of Johnson \& Johnson is available at www.janssen.com/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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