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Prostatic NeoplasmsPhase 1NCT06136598

A Study of Opevesostat (MK-5684) in China Participants With Metastatic Castration-Resistant Prostate Cancer (mCRPC) (MK-5684-001)

A Phase 1 study testing Opevesostat, Dexamethasone and Fludrocortisone in people with Prostatic Neoplasms and Metastatic Castration-Resistant Prostate Cancer, run by Merck Sharp & Dohme LLC at 3 sites in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The primary objectives of this study are to evaluate the safety and tolerability of opevesostat in the treatment of male Chinese participants with metastatic castration-resistant prostate cancer (mCRPC) and to characterize the pharmacokinetic profile of opevesostat. Read more about this study

Who is it for?
Ages 18 years and older, men only
What is being tested?
Opevesostat, Dexamethasone and Fludrocortisone
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
14 participants
Where
3 sitesChina
Study dates
30 Jan 2024to 9 Mar 2026
Phase
Phase 1
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Men only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Has histologically or cytologically confirmed adenocarcinoma of the prostate without small cell histology.
  • Has prostate cancer while receiving androgen deprivation therapy (ADT), or post-bilateral orchiectomy, within 6 months before screening.
  • Has evidence of progression >4 weeks since last flutamide treatment or >6 weeks since last bicalutamide or nilutamide treatment.
  • Has evidence of metastatic disease documented by either bone lesions on bone scan and/or soft tissue shown by CT/MRI.
  • Has disease that progressed during or after treatment with at least 1 line of next-generation hormonal agents (NHAs) for hormone-sensitive prostate cancer (HSPC) or castration-resistant prostate cancer (CRPC) for at least 8 weeks (at least 14 weeks for participants with bone progression).
  • Has received at least 1 line of taxane-based chemotherapy for HSPC or CRPC and have had progressed disease during or on treatment, or refused or ineligible to receive chemotherapy.
  • Has a life expectancy of >3 months.

Who cannot join

  • Has history of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 3 years.
  • Has presence of gastrointestinal condition, e.g. malabsorption, that might affect the adsorption of study intervention.
  • Has a history of pituitary dysfunction.
  • Has poorly controlled diabetes mellitus.
  • Has active or unstable cardio/cerebro-vascular disease, including thromboembolic events.
  • Has undergone major surgery, including local prostate intervention (except prostate biopsy), within 4 weeks of the date of allocation.
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  • Has received an anticancer monoclonal antibody (mAb) within 4 weeks of allocation, or has not recovered from adverse events (AEs) due to mAbs administered more than 4 weeks before the date of allocation.
  • Received prior systemic anticancer therapy including investigational agents within 4 weeks before the date of allocation.
  • Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any form of immunosuppressive therapy within 7 days prior to the start of study intervention.
  • Has a known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
  • Has an active autoimmune disease that has required systemic treatment in the past 2 years.
  • Has a history of or current human immunodeficiency virus (HIV) infection.
  • Has a concurrent Hepatitis B or Hepatitis C virus infection.
  • Has a history of allogenic tissue or solid organ transplant.

Trial locations and contacts

3 sites in 1 country.

China3 sites

  • Peking University First Hospital-Urology ( Site 0001)

    Beijing, Beijing Municipality, 100034

  • Sun Yat-sen University Cancer Center-Neurosurgery department ( Site 0003)

    Guangzhou, Guangdong, 510700

  • Tongji Hospital Tongji Medical,Science & Technology ( Site 0002)

    Wuhan, Hubei, 430000

Other trials in China

About this study

Official title: A Phase 1 Clinical Study to Investigate the Safety and Pharmacokinetics of MK-5684 in China Participants With Metastatic Castration-Resistant Prostate Cancer

The primary objectives of this study are to evaluate the safety and tolerability of opevesostat in the treatment of male Chinese participants with metastatic castration-resistant prostate cancer (mCRPC) and to characterize the pharmacokinetic profile of opevesostat. There are no formal hypotheses to be tested in this study.

Being tested
Opevesostat, Dexamethasone, Fludrocortisone, Hydrocortisone
Medical subject headings
Prostatic Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • OpevesostatDrug

    Also called MK-5684

    Tablets to be taken orally.

  • DexamethasoneDrug

    Also called Dexamethasone acetate

    Tablets to be taken orally

  • FludrocortisoneDrug

    Also called Fludrocortisone acetate

    Tablets to be taken orally.

  • HydrocortisoneDrug

    Also called Hydrocortisone acetate

    Tablet to be taken orally as a rescue medication.

Study groups in NCT06136598
Study groupRoleWhat they receive
OpevesostatExperimentalParticipants will receive opevesostat by oral tablets twice daily plus dexamethasone and fludrocortisone by oral tablets once daily continuously until unacceptable toxicity or documented progression. Hydrocortisone will also be provided to participants for use as rescue medication.
Receives: Drug: Opevesostat; Drug: Dexamethasone; Drug: Fludrocortisone; Drug: Hydrocortisone

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants Who Experience an Adverse Event (AE)

    An AE is defined as any untoward medical occurrence associated with the use of a drug in a participant, whether or not considered drug related. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a medicinal product and does not imply any judgment about causality.

    Measured: Up to approximately 20 months

  2. Number of Participants Who Discontinue Study Intervention Due to an AE

    An AE is defined as any untoward medical occurrence associated with the use of a drug in a participant, whether or not considered drug related. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a medicinal product and does not imply any judgment about causality.

    Measured: Up to approximately 20 months

  3. Maximum Plasma Concentration (Cmax) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the Cmax of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

  4. Time to Maximum Plasma Concentration (Tmax) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the Tmax of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

  5. Area Under the Curve from Time 0 to 12 hours postdose (AUC0-12) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the AUC0-12 of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

  6. Apparent Volume of Distribution (Vz/F) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the Vz/F of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

  7. Oral Clearance (CL/F) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the CL/F of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

  8. Half-Life (t1/2) of opevesostat

    Blood samples will be collected at pre-specified timepoints to determine the t1/2 of opevesostat.

    Measured: Day 1 and Day 8: predose and 0.5, 1, 2, 3, 4, 6, 9, and 12 hours postdose, Day 29, Day 57, and Day 89: pre-dose

Secondary outcomes (6)

  1. Prostate-specific Antigen (PSA) Response Rate

    The PSA response rate is defined as the percentage of participants in the analysis population with a reduction in PSA level of ≥50% measured twice ≥3 weeks apart.

    Measured: Up to approximately 37 months

  2. Radiographic Progression-free Survival (rPFS) Per Prostate Cancer Working Group (PCWG)-modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)

    rPFS is defined as the time from first dose of study intervention to radiographic progression per PCWG-modified RECIST 1.1 as assessed by the investigator OR death due to any cause, whichever occurs first.

    Measured: Up to approximately 37 months

  3. Objective Response Rate (ORR) Per PCWG-modified RECIST 1.1

    ORR is defined as the percentage of participants who have a best overall response of either confirmed Complete Response (CR: disappearance of all target lesions) or a confirmed Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per PCWG-modified RECIST 1.1 as assessed by the investigator.

    Measured: Up to approximately 37 months

  4. Duration of Response (DOR) Per PCWG-modified RECIST 1.1

    For participants who demonstrate a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per PCWG-modified RECIST 1.1, DOR is defined as the time from first documented evidence of confirmed CR or PR until disease progression or death from any cause, whichever occurs first.

    Measured: Up to approximately 37 months

  5. Overall Survival (OS)

    OS is defined as time from first dose of study intervention to death due to any cause.

    Measured: Up to approximately 37 months

  6. Blood Concentrations of Steroids

    Blood samples collected at multiple timepoints after the administration of opevesostat will be used to determine the blood concentrations of steroids.

    Measured: At designated timepoints (up to approximately 37 months)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Nov 2023
  2. Study start30 Jan 2024
  3. Primary completion9 Mar 2026
  4. Study completion9 Mar 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
14 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06136598
Sponsor's protocol ID
5684-001
Other IDs
MK-5684-001
Status last verified
Mar 2026
First submitted
13 Nov 2023
Last updated
19 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing Opevesostat, Dexamethasone and Fludrocortisone in people with Prostatic Neoplasms and Metastatic Castration-Resistant Prostate Cancer, run by Merck Sharp & Dohme LLC at 3 sites in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants Who Experience an Adverse Event (AE) (time frame: Up to approximately 20 months). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06136598.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Mar 2026.

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