A Clinical Study Evaluating The Benefit of Adding Rucaparib to Enzalutamide for Men With Metastatic Prostate Cancer That Has Become Resistant To Testosterone-Deprivation Therapy — CASPAR  

Castration-Resistant Prostate Carcinoma Clinical Trial

Official title: CASPAR - A Phase III Trial of Enzalutamide and Rucaparib as a Novel Therapy in First-Line Metastatic Castration-Resistant Prostate Cancer

Status Active, not recruiting

Clinical Trial Summary

This randomized, placebo-controlled phase III trial is evaluating the benefit of rucaparib and enzalutamide combination therapy versus enzalutamide alone for the treatment of men with prostate cancer that has spread to other places in the body (metastatic) and has become resistant to testosterone-deprivation therapy (castration-resistant). Enzalutamide helps fight prostate cancer by blocking the use of testosterone by the tumor cells for growth. Poly adenosine diphosphate (ADP)-ribose polymerase (PARP) inhibitors, such as rucaparib, fight prostate cancer by prevent tumor cells from repairing their DNA. Giving enzalutamide and rucaparib may make patients live longer or prevent their cancer from growing or spreading for a longer time, or both. It may also help doctors learn if a mutation in any of the homologous recombination DNA repair genes is helpful to decide which treatment is best for the patient.

Clinical Trial Description

PRIMARY OBJECTIVES:

I. To compare radiographic progression-free survival (rPFS) and overall survival (OS) with enzalutamide and rucaparib camsylate (rucaparib) versus enzalutamide alone for patients with metastatic castration resistant prostate cancer commencing first-line therapy.

II. (PK substudy) To evaluate the safety and tolerability of rucaparib and enzalutamide combination III. (Quality of life substudy) To compare quality of life as measured by FACT-P Trial Outcome Index in patients with mCRPC who receive enzalutamide plus rucaparib vs enzalutamide alone at the 12-month time point (primary QOL timepoint).

SECONDARY OBJECTIVES:

I. To compare rPFS and OS with enzalutamide and rucaparib versus enzalutamide alone within homologous-recombination repair (HRR) aberrant and wild-type patients.

II. To evaluate the effects of concurrent administration of rucaparib on time to unequivocal clinical progression.

III. To evaluate the effects of concurrent administration of rucaparib on best radiographic response using Prostate Cancer Working Group 3 (PCWG3) criteria.

IV. To evaluate the effects of concurrent administration of rucaparib on duration of overall response.

V. To evaluate the effects of concurrent administration of rucaparib on prostate specific antigen (PSA) response rate.

VI. To evaluate the effects of concurrent administration of rucaparib on best response by serum PSA by months 7 and 13.

VII. To evaluate the effects of concurrent administration of rucaparib on time to first symptomatic skeletal event (SSE).

VIII. To evaluate the effects of concurrent administration of rucaparib on safety and tolerability as measured by National Cancer Institute (NCI) Common Toxicity Criteria; and trial discontinuation for treatment emergent toxicities.

IX. To compare performance of plasma-based and tissue-based genomic profiling in detection of homologous-recombination repair mutation (HRRm) in metastatic castration-resistant prostate cancer (mCRPC).

OUTLINE:

In the randomized, placebo-controlled phase III study, patients will be randomized to 1 of 2 arms:

ARM I: Patients will receive enzalutamide orally (PO) once daily (QD) and rucaparib PO twice daily (BID). Patients who did not undergo bilateral orchiectomy will also receive androgen deprivation therapy (ADT) consisting of leuprolide acetate intramuscularly (IM), goserelin acetate subcutaneously (SC) every 12 weeks or degarelix SC. Cycles will repeat every 28 days in the absence of disease progression or unacceptable toxicity.

ARM II: Patients will receive enzalutamide PO QD and placebo PO BID. Patients who did not undergo bilateral orchiectomy will also receive ADT consisting of leuprolide acetate IM, goserelin acetate SC every 12 weeks or degarelix SC. Cycles will repeat every 28 days in the absence of disease progression or unacceptable toxicity.

After the completion of study treatment, patients will be followed every 3 months for 2 years, then every 6 months for 3 years. ;

Related Conditions & MeSH terms

• Castration-Resistant Prostate Carcinoma
• Metastatic Prostate Adenocarcinoma
• Prostatic Neoplasms
• Stage IV Prostate Cancer AJCC v8
• Stage IVA Prostate Cancer AJCC v8
• Stage IVB Prostate Cancer AJCC v8

• NCT number: NCT04455750
• Study type: Interventional
• Source: Alliance for Clinical Trials in Oncology
• Status: Active, not recruiting
• Phase: Phase 3
• Start date: February 19, 2021
• Completion date: September 2026