Study of Opevesostat for Metastatic Castration-Resistant Prostate Cancer
This study is looking at a new treatment called opevesostat for men with metastatic castration-resistant prostate cancer (mCRPC), which is prostate cancer that has spread and is no longer responding to standard hormone therapy. Researchers want to see if opevesostat can help people live longer compared to other common treatments like abiraterone acetate or enzalutamide. You might be able to join if you have prostate cancer that has spread, has gotten worse despite hormone therapy, and you've already had certain treatments. The study will measure how long people live, up to about 54 months, to see if opevesostat is more effective.
- Study design
- This is a Phase 3, randomized, open-label study involving 1310 participants. This means participants will be randomly assigned to receive either opevesostat or an alternative treatment, and both you and your doctors will know which treatment you are receiving.
- What's involved
- Not specified in the trial record.
- Compensation
- Not stated in the trial record.
- Follow-up
- The study will follow participants for overall survival for up to approximately 54 months.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT06136624
Study of Opevesostat (MK-5684) Versus Alternative NHA in mCRPC (MK-5684-003)
Recruiting
PHASE3Ages 18+InterventionalTreatmentMerck Sharp & Dohme LLC
~1,310 participants
Updated 2026-08-28 on ClinicalTrials.gov
What's tested:OpevesostatAbiraterone acetateEnzalutamideHydrocortisoneFludrocortisone acetatePrednisone
At a glance
Recruiting sites
237 of 288 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Overall Survival (OS) in Androgen Receptor Ligand Binding Domain (AR LBD) Mutation-Positive Participants
Measured over Up to ~54 months
+1 more outcome measured
Conditions
Where it's being run
288 sites across 172 statesJapan11
Turkey (Türkiye)9
Israel6
South Dakota5
Zhejiang5
Taiwan5
Colorado4
Quebec4
Study leadership
- Medical Director · STUDY_DIRECTOR · Merck Sharp & Dohme LLC
Who to contact
Opens a ready-to-send draft in your own email app — review before sending.
Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology.
Has prostate cancer progression while on androgen deprivation therapy (or post bilateral orchiectomy) within 6 months before Screening
Has current evidence of distant metastatic disease (M1 disease) documented by either bone lesions on bone scan and/or soft tissue disease by computed tomography/magnetic resonance imaging (CT/MRI).
Has disease that progressed during or after treatment with 1 novel hormonal agent (NHA)
Has received 1 but no more than 2 taxane-based chemotherapy regimens for metastatic castration-resistant prostate cancer (mCRPC) and has had progressive disease (PD) during or after treatment
Has ongoing androgen deprivation with serum testosterone \<50 ng/dL (\<1.7 nM)
Has provided tumor tissue from a fresh core or excisional biopsy from soft tissue not previously irradiated
Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 assessed within 7 days of randomization
Has had prior treatment with PARPi or were deemed ineligible to receive treatment by the investigator or have refused PARPi treatment
Has received prior 177Lu-PSMA-617 or were deemed ineligible to receive 177Lu-PSMA-617 treatment by the investigator or refused 177Lu-PSMA-617 treatment
Participants who have not received cabazitaxel can be enrolled if they are ineligible for cabazitaxel treatment as determined by the investigator or have refused treatment
If participant received first generation anti-androgen therapy before screening, the participant has evidence of disease progression \>4 weeks since the last flutamide treatment and \>6 weeks since the last bicalutamide or nilutamide treatment
Participants receiving bone resorptive therapy (including, but not limited to, bisphosphonate or denosumab) must have been on stable doses for ≥ 4 weeks before the date of randomization
Participants with human immunodeficiency virus (HIV) infection must have well controlled HIV on antiretroviral therapy (ART)
Participants who are hepatitis B surface antigen (HBsAg) positive are eligible if they have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks and have undetectable HBV viral load before randomization
Participants with history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable at Screening.
Participants who can produce sperm must agree to the following during the study treatment period and for at least 7 days after the last dose of opevesostat, for at least 30 days after the last dose of abiraterone acetate, and for at least 3 months after the last dose of enzalutamide: EITHER be abstinent OR must agree to use male condom
Exclusion
Has a gastrointestinal disorder that might affect absorption
Has a history of pituitary dysfunction
Has poorly controlled diabetes mellitus
Has clinically significant abnormal serum potassium or sodium level
Has a history of active or unstable cardio/cerebro-vascular disease, including thromboembolic events
Has a history of seizure within 6 months of providing documented informed consent or any condition that may predispose to seizures within 12 months before the date of randomization
Has a history of clinically significant ventricular arrhythmias
Has received an anticancer monoclonal antibody (mAb) within 4 weeks before the date of randomization, or has not recovered from adverse events (AEs) due to mAbs administered more than 4 weeks before the date of randomization
Has undergone major surgery, including local prostate intervention (except prostate biopsy), within 28 days before the date of randomization, and has not recovered from the toxicities and/or complications
Participants who have not adequately recovered from major surgery or have ongoing surgical complications
Has used herbal or medicinal products that may have hormonal anti-prostate cancer activity and/or are known to decrease prostate-specific Antigen (PSA) (eg, saw palmetto, megesterol acetate, citrus pectin polysaccharide) within 4 weeks before the date of randomization
Has received radium-223 or Lutetium-177 within 4 weeks before the date of randomization, or has not recovered to Grade ≤1 or baseline from AEs due to radium-223 or Lutetium-177 administered more than 4 weeks before the date of randomization
Has received treatment with 5-αreductase inhibitors (eg, finasteride or dutasteride), estrogens, or cyproterone within 4 weeks before the date of randomization
Has received colony-stimulating factors within 28 days before the date of randomization
Has received a whole blood transfusion in the last 120 days before the date of randomization. Packed red blood cells and platelet transfusions are acceptable if not given within 28 days of the date of randomization
Has received prior targeted small molecule therapy or NHA treatment within 4 weeks before the first dose of study intervention as follows: enzalutamide or apalutamide within 3 weeks or abiraterone acetate + prednisone or darolutamide within 2 weeks
Has a "superscan" bone scan
Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior the first dose of study medication
Has a known additional malignancy that is progressing or has required active treatment within the past 3 years
Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
Has an active autoimmune disease that has required systemic treatment in past 2 years
Has an active infection requiring systemic therapy
Has concurrent active HBV or known active HCV infection
Has a history of long QTc syndrome
Has any of the following at Screening Visit: hypotension (systolic BP \<110 mm Hg) or uncontrolled hypertension (systolic BP ≥160 mm Hg or diastolic BP ≥90 mm Hg, in 2 out of 3 recordings with optimized antihypertensive therapy)
Is unable to swallow capsules/tablets
Is currently being treated with cytochrome 450-inducing antiepileptic drugs for seizures
Participants on an unstable dose of thyroid hormone therapy within 6 months before the start of the study intervention
Received prior systemic anticancer therapy including investigational agents within 4 weeks before the first dose of study intervention
Received prior radiotherapy within 2 weeks of start of study intervention, or radiation-related toxicities, requiring corticosteroids
Received a live or live-attenuated vaccine within 30 days before the first dose of study intervention
Systemic use of the following medications within 2 weeks before the first dose of study intervention: strong CYP3A4 inducers (eg, avasimibe, carbamazepine, lumacaftor, phenobarbital, rifampicin, rifapentine, or St John's Wort); P-gp inhibitors (eg, erythromycin, clarithromycin, rifampicin, ketoconazole, itraconazole, posaconazole, artesunate-pyronaridine, ritonavir, indinavir, nelfinavir, atazanavir, glecaprevir-pibrentasvir, simeprevir, ledipasvir-sofosbuvir, verapamil, diltiazem, dronedarone, propafenone, quinidine, cyclosporine, valspodar, or milk thistle \[Silybum marianum\])
Use of aldosterone antagonist (eg, spironolactone, eplerenone) and phenytoin within 4 weeks before the start of the study intervention
What this trial measures
- Overall Survival (OS) in Androgen Receptor Ligand Binding Domain (AR LBD) Mutation-Positive ParticipantsUp to ~54 months
OS is defined as time from randomization to death due to any cause. OS in AR LBD mutation-positive participants will be reported for each study arm.
- OS in AR LBD Mutation-Negative ParticipantsUp to ~54 months
OS is defined as time from randomization to death due to any cause. OS in AR LBD mutation-negative participants will be reported for each study arm.