PainPhase 1NCT07378865
Evaluation of the Excretion of Suzetrigine Into Breast Milk in Healthy Lactating Female Participants
A Phase 1 study testing Suzetrigine in people with Pain, run by Vertex Pharmaceuticals Incorporated at 1 site in United States.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Pain
- What is being tested?
- Suzetrigine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Feb 2026to 17 Aug 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
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
- Participant agrees to abstain from donating or feeding their infant any breast milk produced after receiving SUZ through the completion of the Safety Follow-up Visit (SFUV)
Who cannot join
- 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
- Other protocol defined Inclusion/Exclusion criteria may apply.
Trial locations and contacts
1 site in 1 country.
United States1 site
ICON - Utah - Salt Lake City Office
Salt Lake City, Utah, 84124
About this study
Official title: A Phase 1, Open-label, Single-dose Study Evaluating the Excretion of Suzetrigine Into Breast Milk in Healthy Lactating Female Subjects
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.
Read the detailed description
The study is being conducted to evaluate the PK, safety and tolerability of SUZ and its active metabolite in lactating female participants.
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.).
- Conditions
- Pain
- Being tested
- Suzetrigine
- Medical subject headings
- Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SuzetrigineDrug
Also called VX-548, SUZ, JOURNAVX
Tablets for Oral Administration.
| Study group | Role | What they receive |
|---|---|---|
| SUZ | Experimental | Participants will receive a single dose of SUZ on Day 1. Receives: Drug: Suzetrigine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total Amount of SUZ in Breast Milk of Lactating Female Participants
Measured: From Day 1 up to Day 10
Total Amount of SUZ Metabolite in Breast Milk of Lactating Female Participants
Measured: From Day 1 up to Day 10
Secondary outcomes (4)
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
Measured: From Day 1 up to Day 10
Maximum Observed Concentration (Cmax) of SUZ and its Metabolite in Breast Milk
Measured: From Day 1 up to Day 10
RID of SUZ and its Metabolite From Breast Milk
Measured: 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)
Measured: From Day 1 up to Day 16
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jan 2026
- Study start13 Feb 2026
- Primary completion17 Aug 2026
- Study completion17 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PainStudies of the same condition, open and under way.
- More trials run by Vertex Pharmaceuticals IncorporatedThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vertex Pharmaceuticals Incorporated
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07378865
- Sponsor's protocol ID
- VX25-548-021
- Status last verified
- Sep 2026
- First submitted
- 23 Jan 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: 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/
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, Open-label, Single-dose Study Evaluating the Excretion of Suzetrigine Into Breast Milk in Healthy Lactating Female Subjects
- ClinicalTrials.gov ID
- NCT07378865
- Acronym / sponsor ID
- VX25-548-021
- Conditions
- Pain
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- Vertex Pharmaceuticals IncorporatedIndustry (pharma, biotech, devices)
- Study start
- 13 Feb 2026 (actual)
- Primary completion
- 17 Aug 2026 (actual)
- Study completion
- 17 Aug 2026 (actual)
- First posted
- 30 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
The study is being conducted to evaluate the PK, safety and tolerability of SUZ and its active metabolite in lactating female participants.
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 design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| SUZ | Experimental | Drug: SuzetrigineParticipants will receive a single dose of SUZ on Day 1. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 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
- Participant agrees to abstain from donating or feeding their infant any breast milk produced after receiving SUZ through the completion of the Safety Follow-up Visit (SFUV)
Key exclusion criteria (5 listed)
- 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
- Other protocol defined Inclusion/Exclusion criteria may apply.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SuzetrigineAlso: VX-548, SUZ, JOURNAVXTablets for Oral Administration. | Drug | SUZ |
Primary outcome
Total Amount of SUZ in Breast Milk of Lactating Female Participants
Time frame: From Day 1 up to Day 10
Total Amount of SUZ Metabolite in Breast Milk of Lactating Female Participants
Time frame: From Day 1 up to Day 10
4 secondary outcomes
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
Time frame: From Day 1 up to Day 10
Maximum Observed Concentration (Cmax) of SUZ and its Metabolite in Breast Milk
Time frame: From Day 1 up to Day 10
RID of SUZ and its Metabolite From Breast Milk
Time frame: 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)
Time frame: From Day 1 up to Day 16
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: No. 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/
Related trials for Pain
Not yet recruiting
Effect of Stress Ball Use During Femoral Arterial Sheath Removal After Coronary Angiography
Femoral Arterial Sheath Removal, Stress Ball
Recruiting
Empowered Relief® for Cancer Survivors With Chronic Pain
Chronic Pain Due to Cancer, Pain Catastrophizing
RecruitingPhase 4
ESP Blocks for Posterior Spinal Fusion
Postoperative Pain
RecruitingObservational study
Pain Phenotypes in Individuals With Multiple Sclerosis
Multiple Sclerosis, Chronic Pain
Not yet recruiting
Effects of Hip Hinge Exercises on Pain, Range of Motion and Functional Disability in Non-specific Low Back Pain.
Low Back Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Suzetrigine in people with Pain, run by Vertex Pharmaceuticals Incorporated at 1 site in United States.
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 5 inclusion and 5 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 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. 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?
Total Amount of SUZ in Breast Milk of Lactating Female Participants (time frame: From Day 1 up to Day 10). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 9 Sep 2026.