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Antiandrogen

Rucaparib + Enzalutamide for Prostate Cancer (CASPAR Trial)

Phase 3
Waitlist Available
Research Sponsored by Alliance for Clinical Trials in Oncology
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Measurable or non-measurable metastatic disease
No clinical, laboratory or radiographic evidence of an active bacterial, fungal, or viral infection requiring treatment at the time of registration
Timeline
Screening 3 weeks
Treatment Varies
Follow Up up to 5 years post treatment
Awards & highlights
Pivotal Trial

Summary

This trial is testing if a combination of two drugs, rucaparib and enzalutamide, is better than enzalutamide alone for treating men with prostate cancer that has spread and become resistant to testosterone-deprivation therapy.

Who is the study for?
Men with metastatic prostate cancer resistant to testosterone-deprivation therapy are eligible. They must have documented prostate adenocarcinoma, radiographic progression, and no central nervous system metastases that aren't stable or treated. Participants need to be off certain drugs affecting liver enzymes and recovered from major surgeries or treatments. No prior treatment for metastatic castration-resistant prostate cancer is allowed.
What is being tested?
The trial tests if adding Rucaparib (a PARP inhibitor) to Enzalutamide improves outcomes in men whose prostate cancer has spread and resists hormone therapy. It's a phase III study where patients are randomly assigned either the combination of both drugs or Enzalutamide alone, plus placebos as needed.
What are the potential side effects?
Possible side effects include fatigue, nausea, changes in blood counts leading to increased infection risk or bleeding problems, liver function changes, potential heart issues like arrhythmias or angina, seizures for those at risk, and other common drug-related reactions.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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My cancer has spread and can be measured or not.
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I do not have any active infections needing treatment right now.
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I am able to care for myself and perform daily activities.
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I haven't had serious heart issues or strokes in the last 3 months.
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My liver functions well and I don't have severe liver disease.
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I am not taking strong medication that affects certain liver enzymes.
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I am not allergic to enzalutamide, rucaparib, or their ingredients.
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I do not have untreated spinal issues related to cancer.
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My prostate cancer has spread to my bones and is getting worse.
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I don't have plans for treatments specifically for bone pain relief.
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I don't have a history of long-term low blood counts without a known cause.
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I do not have any stomach or bowel problems affecting medication absorption.
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I have not received any treatment for prostate cancer that has spread and is resistant to hormonal therapy.
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It's been over 2 weeks since my last cancer-related medication.
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My prostate cancer has been confirmed by lab tests.
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My cancer has worsened despite hormone therapy or after surgical removal of testicles.
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I have not been treated with enzalutamide, rucaparib, any PARP inhibitor, or platinum chemotherapy.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~up to 5 years post treatment
This trial's timeline: 3 weeks for screening, Varies for treatment, and up to 5 years post treatment for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Overall survival (OS)
Radiographic progression-free survival (rPFS)
Secondary study objectives
Best response by serum prostate specific antigen (PSA)
Therapeutic procedure
Duration of overall response
+7 more
Other study objectives
Laboratory correlative science
Quality of life

Awards & Highlights

Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

Trial Design

2Treatment groups
Experimental Treatment
Active Control
Group I: Arm I (enzalutamide, rucaparib)Experimental Treatment7 Interventions
Patients receive enzalutamide PO QD and rucaparib PO BID. Patients who did not undergo bilateral orchiectomy also receive ADT consisting of leuprolide acetate IM, goserelin acetate SC every 12 weeks or degarelix SC. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity.
Group II: Arm II (enzalutamide, placebo)Active Control6 Interventions
Patients receive enzalutamide PO QD and placebo PO BID. Patients who did not undergo bilateral orchiectomy also receive ADT consisting of leuprolide acetate IM, goserelin acetate SC every 12 weeks or degarelix SC. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Goserelin Acetate
2007
Completed Phase 3
~1040
Enzalutamide
2014
Completed Phase 4
~3820
Degarelix
2002
Completed Phase 3
~3730
Rucaparib camsylate
2018
Completed Phase 1
~20
Leuprolide Acetate
2002
Completed Phase 3
~1890

Find a Location

Who is running the clinical trial?

Alliance for Clinical Trials in OncologyLead Sponsor
518 Previous Clinical Trials
222,276 Total Patients Enrolled
29 Trials studying Prostate Cancer
5,836 Patients Enrolled for Prostate Cancer
National Cancer Institute (NCI)NIH
13,957 Previous Clinical Trials
41,112,026 Total Patients Enrolled
516 Trials studying Prostate Cancer
332,960 Patients Enrolled for Prostate Cancer
Arpit Rao, MDStudy ChairBaylor College of Medicine
~13 spots leftby Dec 2025