A Clinical Study of Belzutifan (MK-6482) Alone or With Phenytoin in Healthy Participants (CA46602/MK-6482-035)

NCT06903715 | Completed Phase 1 FDA Drug

• 2 other identifiers: 6482-035CA46602
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

Brief Summary

Researchers designed belzutifan, the study medicine, to treat certain kinds of cancer. The goal of this study is to learn what happens to belzutifan in a healthy person's body over time when taken, by mouth, as a tablet. Researchers will learn what happens when belzutifan is taken alone and when it is taken after several days of treatment with phenytoin.

Conditions

Healthy

Outcome Measures

Primary Outcomes (1)

• Area Under the Concentration-Time Curve from Time 0 to Infinity (AUC0-Inf) of Belzutifan

  Blood samples will be collected to determine the AUC0-inf of belzutifan.

  Predose and at designated timepoints up to 120 hours postdose

Secondary Outcomes (10)

• Number of Participants Who Experience an Adverse Event (AE)

  Up to approximately 36 days

• Number of Participants Who Discontinue Study Drug Due to an AE

  Up to approximately 22 days

• Area Under the Concentration-Time Curve from Time 0 to Last (AUC0-last) of Belzutifan in Plasma

  Predose and at designated timepoints up to 120 hours postdose

• Area Under the Concentration-Time Curve from Time 0 to 24 Hours (AUC0-24) of Belzutifan in Plasma

  Predose and at designated timepoints up to 24 hours postdose

• Maximum Plasma Concentration (Cmax) of Belzutifan in Plasma

  Predose and at designated timepoints up to 120 hours postdose

Study Arms (1)

Belzutifan + Phenytoin

EXPERIMENTAL

Participants receive belzutifan during study Period 1, followed by a washout period, then they receive belzutifan and phenytoin during study Period 2.

Drug: Belzutifan; Drug: Phenytoin

Interventions

Belzutifan DRUG

Oral administration

Also known as: MK-6482, PT2977, Welireg™

Belzutifan + Phenytoin

Phenytoin DRUG

Oral administration

Also known as: Phenytoin sodium

Belzutifan + Phenytoin

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy, adult, male (vasectomized or surgically sterilized) or female (of non-childbearing potential)
• Has a body mass index (BMI) ≥ 18.0 and ≤ 32.0 kg/m2

You may not qualify if:

• Has a history of any illness that, in the opinion of the PI or designee, might confound the results of the study or poses an additional risk to the participant by their participation in the study
• History or presence of: Seizure (excluding simple febrile seizure), epilepsy, severe head injury, multiple sclerosis, or other known neurological conditions which the PI considers to be clinically significant; Hypersensitivity reaction to anticonvulsant therapy (including phenytoin, primidone, and phenobarbital); Depression, unusual changes in mood or behavior or suicidal thoughts and behavior; Hepatic porphyria (e.g., acute intermittent porphyria, variegate porphyria, porphyria cutanea tarda)

Sponsors & Collaborators

• Merck Sharp & Dohme LLC: lead

Study Sites (1)

Celerion, Inc. ( Site 0001)

Tempe, Arizona, 85283, United States

Location

Related Links

• Merck Clinical Trials Information

MeSH Terms

Interventions

belzutifan; Phenytoin

Intervention Hierarchy (Ancestors)

Hydantoins; Imidazolidines; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Medical Director

  Merck Sharp & Dohme LLC

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 25, 2025
• First Posted: April 1, 2025
• Study Start: March 28, 2025
• Primary Completion: May 8, 2025
• Study Completion: May 27, 2025
• Last Updated: June 13, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share

Locations

US (1)