NCT04986423 · Zenith Epigenetics
ZEN003694 and Enzalutamide Versus Enzalutamide Monotherapy in Metastatic Castration-Resistant Prostate Cancer
What this study is about
This is an where both patients and doctors know the treatment given, randomly assigned, Phase 2b study of ZEN003694 in combination with enzalutamide vs. enzalutamide treatment given alone in patients with mCRPC who have progressed on prior abiraterone by PCWG3 criteria. Disease must have progressed on only abiraterone by PCWG3 criteria prior to study entry.
View original scientific description
This is an open-label, randomized, Phase 2b study of ZEN003694 in combination with enzalutamide vs. enzalutamide monotherapy in patients with mCRPC who have progressed on prior abiraterone by PCWG3 criteria. Disease must have progressed on only abiraterone by PCWG3 criteria prior to study entry.
Interventions
DRUG
ZEN003694
72 mg PO QD
DRUG
Enzalutamide
160 mg PO QD
Primary outcome measures
Cohort A: Radiographic progression-free survival (rPFS) by BICR
Time frame: Randomization up to 30 months
Time from date of randomization to the date of first disease radiographic progression or death for any reason. Radiographic progression disease will be evaluated by RECIST 1.1 and PCWG3.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Males age ≥ 18 years 2. Metastatic, castration-resistant, histologically confirmed prostate cancer 3. Surgical castration or continuous medical castration for ≥ 8 weeks prior to screening; serum testosterone \< 50 ng/dL confirmed within 4 weeks of first administration of study drug 4. Have progressed on prior abiraterone treatment by PCWG3 criteria 5. Patients who are not candidates for chemotherapy in the opinion of the investigator or patients who decline chemotherapy 6. Cohort A only - Patient must meet definition of poor responder to abiraterone by one of the following: 1. Abiraterone started in hormone-sensitive prostate cancer (HSPC) disease setting: \< 12 months duration on abiraterone or failure to achieve PSA nadir of 0.2 ng/mL while taking abiraterone 2. Abiraterone started in castrate-resistant prostate cancer (CRPC) disease setting: \< 6 months duration on abiraterone or failure to achieve a PSA50 response 7. Cohort B only - Patient must meet
Where
- Los Angeles, California
- San Francisco, California
- Whittier, California
- Lakewood, Colorado
- Margate, Florida
- Plantation, Florida
- Baton Rouge, Louisiana
- Columbia, Maryland
- Ann Arbor, Michigan
- New York, New York
- Asheville, North Carolina
- Portland, Oregon
And 4 more locations — see the full list below.
Collaborators
Astellas Pharma Inc, Newsoara Biopharma Co., Ltd.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 8, 2026 · Source of record for eligibility and locations