A Study to Evaluate Opevesostat (MK-5684) in Male Participants With Moderate Hepatic Impairment (MK-5684-009)

An Open-Label, Single-Dose Study to Evaluate the Pharmacokinetics of MK-5684 in Male Participants With Moderate Hepatic Impairment

Researchers have designed a study medicine called opevesostat as a new way to treat prostate cancer.

The purpose of this study is to learn what happens to opevesostat in a person's body over time (a pharmacokinetic [PK] study). Researchers will compare what happens to opevesostat in the body when it is given to healthy participants and participants with moderate hepatic (liver) impairment.

Study Overview

• Status: Completed
• Conditions: Hepatic Impairment; Healthy Participants
• Intervention / Treatment: Drug: Prednisone; Drug: Fludrocortisone acetate; Drug: Opevesostat

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Florida
    • Miami, Florida, United States, 33172
      • Clinical Pharmacology of Miami ( Site 0002)
  • Texas
    • San Antonio, Texas, United States, 78215
      • Texas Liver Institute ( Site 0001)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

The main inclusion criteria include but are not limited to the following:

• All participants:
• Is a continuous non-smoker or moderate smoker (≤ 10 cigarettes per day or equivalent) for at least 3 months prior to dosing
• Has body mass index (BMI) ≥ 18.0 and ≤ 42.0 kg/m2
• Participants with moderate hepatic impairment:
• Has a diagnosis of chronic, stable, hepatic insufficiency with features of cirrhosis due to any etiology

The main exclusion criteria include but are not limited to the following:

• All participants:
• Has a first-degree relative with multiple unexplained syncopal events, unexplained cardiac arrest, or sudden cardiac death, or has a known family history of an inherited arrhythmia syndrome (including Brugada syndrome)
• Has a history of cancer (malignancy)
• Has positive results for human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV)
• Participants with moderate hepatic impairment
• Has unstable electrolyte abnormalities or electrolyte abnormalities that are considered difficult to manage for participants with hepatic impairment
• Has a history of liver or other solid organ transplantation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Moderate Hepatic Impairment; On Day 1, participants with moderate hepatic impairment will receive a single oral dose of opevesostat under fasting conditions and a single dose of hormone replacement therapy (HRT) (prednisone and fludrocortisone acetate) under fed conditions approximately 4.5 hours after opevesostat dosing. Participants with moderate hepatic impairment will receive another dose of HRT on Day 2.	Drug: Prednisone; Oral tablet; Drug: Fludrocortisone acetate; Oral tablet; Drug: Opevesostat; Oral film-coated tablet; Other Names: MK-5684
Experimental: Healthy; On Day 1, healthy participants will receive a single oral dose of opevesostat under fasting conditions and a single dose of HRT (prednisone and fludrocortisone acetate) under fed conditions approximately 4.5 hours after opevesostat dosing.	Drug: Prednisone; Oral tablet; Drug: Fludrocortisone acetate; Oral tablet; Drug: Opevesostat; Oral film-coated tablet; Other Names: MK-5684

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area Under the Concentration Versus Time Curve from 0 to Infinity (AUC0-inf) of Opevesestat	Plasma samples will be collected to determine the AUC0-inf of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Area Under the Concentration Versus Time Curve from 0 to the Last Quantifiable Sample (AUC0-last) of Opevesestat	Plasma samples will be collected to determine the AUC0-last of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Area Under the Concentration Versus Time Curve from 0 to 24 hours (AUC0-24) of Opevesestat	Plasma samples will be collected to determine the AUC0-24 of opevesostat.	At designated timepoints (up to approximately 24 hours post-dose)
Maximum Observed Concentration (Cmax) of Opevesestat	Plasma samples will be collected to determine the Cmax of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Time to Maximum Concentration (Tmax) of Opevesestat	Plasma samples will be collected to determine the Tmax of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Apparent Terminal Half-life (t1/2) of Opevesestat	Plasma samples will be collected to determine the t1/2 of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Apparent Clearance (CL/F) of Opevesestat	Plasma samples will be collected to determine the CL/F of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)
Apparent Volume of Distribution During Terminal Phase (Vz/F) of Opevesestat	Plasma samples will be collected to determine the Vz/F of opevesostat.	At designated timepoints (up to approximately 96 hours post-dose)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants Who Experience One or More Adverse Events (AEs)	An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.	Up to approximately 2 weeks
Number of Participants Who Discontinue Study Due to an AE	An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.	Up to approximately 2 weeks

Collaborators and Investigators

• Sponsor: Merck Sharp & Dohme LLC
• Investigators: Study Director: Medical Director, Merck Sharp & Dohme LLC

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2025
• Primary Completion (Actual): February 9, 2026
• Study Completion (Actual): February 19, 2026

Study Registration Dates

• First Submitted: February 28, 2025
• First Submitted That Met QC Criteria: February 28, 2025
• First Posted (Actual): March 5, 2025

Study Record Updates

• Last Update Posted (Actual): February 24, 2026
• Last Update Submitted That Met QC Criteria: February 20, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Liver Diseases; Polycyclic Compounds; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Pregnadienediols; Prednisone; fludrocortisone acetate
• Other Study ID Numbers: 5684-009; MK-5684-009 (Other Identifier: MSD)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No