NCT05689021

CJNJ-67652000 and Prednisone for Treatment of Metastatic Castration-Resistant Prostate Cancer and SPOP Gene Mutations

Active, enrolled Phase 2 Last updated 7 January 2026

What this trial tests

Phase 2 trial testing Abiraterone Acetate/Niraparib in Castration-Resistant Prostate Carcinoma in 8 participants. Participants enrolled and being followed up; not accepting new ones.

Timeline

5 March 2024

Primary endpoint
31 March 2026

31 March 2026

Quick facts

Lead sponsor	Mayo Clinic
Phase	Phase 2
Status	Active, enrolled
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	treatment
Enrollment	8
Start date	5 March 2024
Primary completion	31 March 2026
Estimated completion	31 March 2026
Sites	3 locations across United States

Drugs / interventions tested

• Abiraterone Acetate/Niraparib — full drug profile →
• Biospecimen Collection — full drug profile →
• Bone Scan — full drug profile →
• Computed Tomography
• Magnetic Resonance Imaging
• Prednisone (prednisone) — full drug profile →

Conditions studied

• Castration-Resistant Prostate Carcinoma — all drugs for Castration-Resistant Prostate Carcinoma →
• Metastatic Prostate Adenocarcinoma — all drugs for Metastatic Prostate Adenocarcinoma →
• Stage IVB Prostate Cancer AJCC v8 — all drugs for Stage IVB Prostate Cancer AJCC v8 →

Sponsor

Mayo Clinic

Who can join

18 and older, male only, with Castration-Resistant Prostate Carcinoma or Metastatic Prostate Adenocarcinoma. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This phase II trial tests how well abiraterone acetate/niraparib (CJNJ-67652000 \[niraparib/abiraterone acetate fixed-dose combination\]) and prednisone works in treating patients with castration-resistant prostate cancer that has spread from where it first started (primary site) to other places in the body (metastatic) and who have a mutation in the SPOP gene. CJNJ-67652000 (niraparib/abiraterone acetate fixed-dose combination) is a drug which stops certain cancer cells from being able to repair themselves from damage, leading to the death of the cancer cell. Prednisone is in a class of medications called corticosteroids. It is used to reduce inflammation and lower the body's immune response to help lessen the side effects of chemotherapy drugs. Giving CJNJ-67652000 and prednisone may kill more tumor cells in patients with metastatic prostate cancer than giving these drugs alone.

Publications & conference data

4 peer-reviewed publications reference this trial (live from Europe PMC):

1. Homologous Recombination Repair Deficiency in Metastatic Prostate Cancer: New Therapeutic Opportunities.
   Piombino C, Pipitone S, Tonni E, Mastrodomenico L, et al · · 2024 · cited 7× · PMID 38731844 · DOI 10.3390/ijms25094624
2. Combination niraparib and abiraterone for HRR-altered metastatic castration-resistant prostate cancer.
   Roberts HN, Maurice-Dror C, Chi KN. · · 2025 · cited 5× · PMID 39711161 · DOI 10.1080/14796694.2024.2442900
3. Hidden tricks in MATH: Hypermorphic mutations in SPOP tumor suppressor explained by cryo-EM.
   Orme JJ, Mer G, Huang H. · · 2023 · cited 2× · PMID 36868187 · DOI 10.1016/j.molcel.2023.02.003
4. Mechanisms underlying prostate cancer sensitivity to reactive oxygen species: overcoming radiotherapy resistance and recent clinical advances.
   Wang M, Xing R, Wang L, Pan M, et al · · 2025 · cited 1× · PMID 40641232 · DOI 10.20892/j.issn.2095-3941.2024.0584