Evaluation of the Excretion of Suzetrigine Into Breast Milk in Healthy Lactating Female Participants

NCT07378865 | Recruiting Phase 1 FDA Drug

• 1 other identifier: VX25-548-021
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of the study is to evaluate the pharmacokinetics (PK) of suzetrigine (SUZ) and its active metabolite in breast milk of lactating female participants. In addition, the purpose is also to evaluate the relative infant dose (RID), safety and tolerability of SUZ and its active metabolite in lactating female participants.

Conditions

Pain

Outcome Measures

Primary Outcomes (4)

• Total Amount of SUZ in Breast Milk of Lactating Female Participants

  From Day 1 up to Day 10

• Total Amount of SUZ Metabolite in Breast Milk of Lactating Female Participants

  From Day 1 up to Day 10

• Area Under the Concentration Versus Time Curve From the Time of Dosing Extrapolated to Infinity (AUC0-inf) of SUZ and its Metabolite in Breast Milk

  From Day 1 up to Day 10

• Maximum Observed Concentration (Cmax) of SUZ and its Metabolite in Breast Milk

  From Day 1 up to Day 10

Secondary Outcomes (2)

• RID of SUZ and its Metabolite From Breast Milk

  From Day 1 up to Day 10

• Safety and Tolerability as Assessed by Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)

  From Day 1 up to Day 16

Study Arms (1)

SUZ

EXPERIMENTAL

Participants will receive a single dose of SUZ on Day 1.

Drug: Suzetrigine

Interventions

Suzetrigine DRUG

Tablets for Oral Administration.

Also known as: VX-548, SUZ, JOURNAVX

SUZ

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Body mass index of greater than or equal to (≥) 18.0 to less than (\<) 40.0 kilogram per meter square (Kg/m\^2) at the Screening Visit
• Participants between 6 weeks and 12 months (inclusive) postpartum from a pregnancy of at least 37 weeks gestation, as of Day 1
• Willing to perform regular pumping to maintain milk supply for the duration of the study
• Participants with well-established lactation, defined as breastfeeding and/or pumping at least 3 times per day

You may not qualify if:

• History of febrile illness or other acute illness that has not fully resolved within 14 days before study drug dosing
• History of breast implants, breast augmentation, or breast reduction surgery that significantly impacts breastfeeding or collection of milk from one or both breasts
• History of any illness or any clinical condition that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the participant
• Pregnant or planning to become pregnant during the study or within 30 days after receiving study drug

Sponsors & Collaborators

• Vertex Pharmaceuticals Incorporated: lead

Study Sites (1)

ICON - Utah - Salt Lake City Office

Salt Lake City, Utah, 84124, United States

RECRUITING

MeSH Terms

Conditions

Pain

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Medical Information

CONTACT

617-341-6777; medicalinfo@vrtx.com

Study Design

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

Study Record Dates

• First Submitted: January 23, 2026
• First Posted: January 30, 2026
• Study Start: February 13, 2026
• Primary Completion (Estimated): February 26, 2027
• Study Completion (Estimated): February 26, 2027
• Last Updated: February 27, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)