Effects of Efavirenz on the Pharmacokinetics of Suzetrigine in Healthy Participants

A Phase 1, Open-label Drug-drug Interaction Study to Evaluate the Effects of Efavirenz on the Pharmacokinetics of Suzetrigine in Healthy Subjects

The purpose of the study is to evaluate the pharmacokinetics (PK) of Suzetrigine (SUZ) and its metabolite in the absence and presence of efavirenz, a moderate CYP3A inducer. In addition, the purpose is to evaluate the safety and tolerability of SUZ when administered in the absence and presence of efavirenz.

Study Overview

• Status: Recruiting
• Conditions: Pain
• Intervention / Treatment: Drug: Suzetrigine; Drug: Efavirenz

Detailed Description

The study is being conducted to evaluate the effects of efavirenz on the PK of SUZ in healthy participants and consists of Screening Phase, Treatment Phase and Safety Follow-up Phase. Participants will receive study medication for a duration of 30 days.

Note: This clinical trial information was submitted voluntarily under the applicable law and, therefore, certain submission deadlines may not apply. (That is, clinical trial information for this applicable clinical trial was submitted under section 402(j)(4)(A) of the Public Health Service Act and 42 CFR 11.60 and is not subject to the deadlines established by sections 402(j)(2) and (3) of the Public Health Service Act or 42 CFR 11.24 and 11.44.).

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Medical Information; Phone Number: 617-341-6777; Email: medicalinfo@vrtx.com

Study Locations

• United States
  • Utah
    • Salt Lake City, Utah, United States, 84124
      • Recruiting
      • ICON - Utah - Salt Lake City Office

Participation Criteria

Eligibility Criteria

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

Description

Key Inclusion Criteria:

• Body mass index (BMI) of 18.0 to 32.0 kilogram per meter square (kg/m^2)
• A total body weight of greater than (>) 50 kg
• Males and females of non-childbearing potential

Key Exclusion Criteria:

• History of any illness or any clinical condition that may confound the results of the study or pose an additional risk in administering study drug to the participant
• History of febrile illness or other acute illness that has not fully resolved within 5 days before the first dose of study drug
• Any condition possibly affecting drug absorption

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SUZ and Efavirenz; Participants will receive a single dose of SUZ on Days 1 through 15. Participants will also receive a single dose of SUZ in the morning followed by a single dose of efavirenz in the evening on Days 16 through 30.	Drug: Suzetrigine; Tablet for oral administration.; Other Names: SUZ; Journavx; Drug: Efavirenz; Tablet for oral administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Maximum Observed Plasma Concentration (Cmax) of SUZ and its Metabolite in the Absence and Presence of Efavirenz	Day 15 and Day 30
Area Under the Concentration Versus Time Curve During a Dosing Interval (AUCτ) of SUZ and its Metabolite in the Absence and Presence of Efavirenz	Day 15 and Day 30

Secondary Outcome Measures

Outcome Measure	Time Frame
Safety and Tolerability as Assessed by Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)	From Day 1 up to Day 46

Collaborators and Investigators

• Sponsor: Vertex Pharmaceuticals Incorporated

Study record dates

Study Major Dates

• Study Start (Actual): May 7, 2026
• Primary Completion (Estimated): July 11, 2026
• Study Completion (Estimated): July 11, 2026

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 6, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; efavirenz
• Other Study ID Numbers: VX24-548-018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/

Drug and device information, study documents

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