This study is designed to evaluate the efficacy of pamiparib in patients with metastatic castration-resistant prostate cancer (mCRPC) positive for circulating tumor cells (CTC) with homologous recombination deficiency (CTC-HRD). All patients will receive pamiparib. The purpose of this study is to demonstrate that pamiparib will improve Objective Response Rate (ORR) and Prostate-Specific Antigen (PSA) response rate



Eligible Ages
Over 18 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Men (> 18 years of age) with histologically or cytologically confirmed adenocarcinoma or poorly differentiated adenocarcinoma of the prostate without neuroendocrine differentiation with HRD deficiency by CTC-HRD assay and/or deleterious germline or somatic mutation in BRCA1 or BRCA2; mCRPC measurable disease and/or bone disease. • PSA progression with > 3 rising PSA levels with > 1 week between determinations and a screening PSA > 2 μg/L (2 ng/mL).
  • Must be surgically or medically castrated with serum testosterone levels of < 1.73 nmol/L (50 ng/dL), must have received > 1 prior androgen receptor-targeted therapy, and must have received > 1 taxane-based therapy.
  • mCRPC with 1 or 2 of the following:
  • Measurable disease per RECIST v1.1
  • Bone disease
  • CTC-HRD+ or BRCA1/2 mutation
  • PSA progression (PCWG3 criteria)
  • ≥1 androgen receptor-targeted therapy (eg, abiraterone acetate/prednisone or enzalutamide) for mCRPC with progressive disease
  • ≥1 taxane for metastatic prostate cancer
  • Prior sipuleucel-T and checkpoint inhibitors"

Exclusion Criteria

  • Chemotherapy, hormonal therapy, biologic therapy, radionuclide therapy, immunotherapy, investigational agent, anticancer Chinese medicine, or herbal remedies ≤ 5 half-lives if the half-life is known, ≤ 14 days if not known, before start of study treatment
  • Continued treatment with a bisphosphonate or denosumab is allowed, if administered at a stable dose > 28 days before start of study treatment
  • Radiotherapy ≤ 21 days (≤ 14 days, if single fraction of radiotherapy) before start of study treatment
  • Prior treatment for prostate cancer with any of the following:
  • PARP inhibitor
  • Platinum
  • Cyclophosphamide
  • Mitoxantrone"

Study Design

Phase 2
Study Type
Intervention Model
Single Group Assignment
Primary Purpose
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Approximately 100 subjects to receive pamiparib orally.
  • Drug: Pamiparib 60 mg PO BID
    Pamiparib 60 mg PO BID
    Other names:
    • pamiparib

Recruiting Locations

Montefiore Einstein Cancer Center
Bronx, New York 10461

More Details


Study Contact

1 (877) 828-5568

Detailed Description

"This is a global, Phase 2, open-label study of pamiparib in approximately 100 patients with with metastatic castration-resistant prostate cancer (mCRPC) positive for circulating tumor cells (CTC) with homologous recombination deficiency (CTC-HRD). Subjects in Cohort 1 will include 50 mCRPC patients with CTC-HRD-positive, measurable metastatic disease (soft tissue with/without bone lesions), and positive BRCA1/2 mutation or negative/unknown BRCA1/2 mutation. Cohort 2 will include 30 mCRPC CTC-HRD positive patients with bone metastasis only and positive or negative/unknown BRCA1/2. Cohort 3 and 4 will include 20 mCRPC CTC-HRD negative/unknown patients with BRCA1/2 positive mutations, metastatic disease (measurable soft tissue with/without bone), and bone only. Subjects will undergo PSA level assessments approximately every 4 weeks as well as tumor assessments every 8 weeks, or as clinically indicated. Administration of pamiparib will continue until disease progression, unacceptable toxicity, death or another discontinuation criterion is met."


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.