How blocking NaV1.8 changes different kinds of pain

The Role of NaV1.8 in Human Pain Models - a Randomized, Placebo-controlled Crossover Microdosing Trial

EARLY_PHASE1 · Medical University of Vienna · NCT07511400

This trial will test whether tiny, local injections of suzetrigine (a NaV1.8 blocker) into the forearm reduce several types of experimentally induced pain in healthy adults.

Quick facts

PhaseEARLY_PHASE1
Study typeInterventional
Enrollment66 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorMedical University of Vienna (other)
Locations1 site (Vienna, State of Vienna)
Trial IDNCT07511400 on ClinicalTrials.gov

What this trial studies

This randomized, placebo-controlled, double-blind crossover microdosing trial gives very small intracutaneous injections of suzetrigine, lidocaine (positive control), or vehicle into separate sites on the volar forearms of healthy volunteers. Each volunteer receives all conditions in randomized order while researchers apply six brief experimental pain challenges—electrical, mechanical, chemical, and thermal modalities—and rate pain on a 0–100 scale. Intracutaneous microdosing is used to produce effective local concentrations with negligible systemic exposure, and the crossover design increases power while reducing between-subject variability. Results will show which pain modalities are reduced by NaV1.8 blockade and help guide development of peripheral, non-opioid analgesics.

Who should consider this trial

Good fit: Healthy adults aged 18–70 with full legal capacity, no interfering medications, no forearm skin disease or sensory deficits, and ability to attend sessions at the Medical University of Vienna are ideal candidates.

Not a fit: People with chronic systemic pain disorders, pregnant or breastfeeding women, those taking other medications (except contraception), or with forearm skin or nerve problems would not receive benefit from or be eligible for this micodosing trial.

Why it matters

Potential benefit: If successful, this work could point to a safer, peripheral non-opioid way to treat certain types of pain by showing that NaV1.8 blockers reduce specific pain modalities.

How similar studies have performed: Selective NaV1.8 inhibitors have shown efficacy in some acute post-surgical pain trials, but modality-specific effects in experimental human pain models remain largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion criteria

* Age between 18 and 70 years
* Full legal capacity Exclusion criteria
* Participant of another study, ongoing or within the last 4 weeks
* Medication intake (except contraception) or drug abuse
* Female subjects: Positive pregnancy test or breastfeeding
* Verified body temperature above 38°C
* Known allergic diseases, in particular asthmatic disorders
* Limited accessibility of forearms (e.g. orthopedic cast)
* Sensory deficit, skin disease or hematoma at the forarms

Where this trial is running

Vienna, State of Vienna

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Pain, Acute Pain, Healthy Volunteer Study, Suzetrigine, VX-548, NaV1.8 Inhibitor, Sodium Channel Blocker, Selective NaV1.8 Antagonist

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.