Safety and Tolerability Study of ST-503 for Refractory Pain Due to Peripheral Neuropathy (Small Fiber Predominant, SFN)

NCT06980948 | Recruiting Phase 1 DMC FDA Drug FDA Device

• 1 other identifier: ST-503-101
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 11

Brief Summary

This research is being done to study a possible treatment for refractory pain due to small fiber neuropathy (SFN). ST-503 is intended to deliver a modified copy of the gene which will ideally repress Nav1.7 tissue-related pain signals reaching the brain, which should reduce the refractory pain due to small fiber neuropathy (SFN).

Conditions

Chronic Neuropathic Pain

Keywords

Small Fiber Neuropathy

Outcome Measures

Primary Outcomes (1)

• Incidence and severity of treatment emergent adverse events (TEAEs)

  To assess safety and tolerability of ST-503 over a 12-week post-dosing observation period.

  12 weeks

Secondary Outcomes (11)

• Percentage of subjects with pain intensity reduction from baseline at Week 12

  12 weeks

• Percentage of subjects at Week 12

  12 weeks

• Columbia Suicide Severity Rating Scale (CSSRS) Rating

  12 weeks

• Overall Pain Intensity Numerical Rating Scale (PI-NRS) score

  12 Weeks

• Short Form McGill Pain Questionnaire-2 (SF-MQ-2)

  12 Weeks

Study Arms (2)

Sham Controlled Study

SHAM COMPARATOR

Procedure: Sham (No Treatment)

Investigational Agent

EXPERIMENTAL

Genetic: ST-503

Interventions

ST-503 GENETIC

Genomic Medicine

Investigational Agent

Sham (No Treatment) PROCEDURE

Sham Procedure

Sham Controlled Study

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnostic characterization of Small Fiber Neuropathy (SFN) according to the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities and Networks (ACTTION) criteria.
• Medical record documentation that pain is refractory to 2 of 3 categories of first line medical therapy for at ≥ 6 months prior to screening.
• Serum sample negative for pre-existing anti-AAV9 antibodies determined by assay detection limit

You may not qualify if:

• Drug- and alcohol-related:
• Persons using opioid analgesics for under 3 months or persons who are not on a stable dose of opioids; if on a stable dose, the dose may decrease over the course of the study but should not be increased.
• History of known alcohol abuse, opioid analgesic abuse, or illicit drug abuse within 2 years of Screening.
• Positive urine test for drugs of abuse (including opiates, benzodiazepines, amphetamines, cocaine, barbiturates, and phencyclidine) without prescription and investigator approval, at Screening and Day -1.
• Use of cannabinoids is not permitted.
• Persons with Fabry's disease, with erythromelalgia, with peripheral neuropathies due to alcohol or drug toxicity, or with diagnosed channelopathies
• Procedure-related:
• Contraindications to LP, general anesthesia or sedation
• Any medical disorders that, in the opinion of the Investigator, could interfere with LP including but not limited to evidence for a pressure gradient between supratentorial and infratentorial compartments, Arnold-Chiari malformation, bleeding diathesis, clinically significant coagulopathy, thrombocytopenia, increased intracranial pressure, or spine disease or past surgical procedures involving the spine
• Infectious disease-related:
• Active viral infection or bacterial
• A severe infection (e.g., pneumonia, septicemia, central nervous system infections \[e.g., meningitis, encephalitis\]) within 12 weeks prior to Screening
• Hepatic disease- and hepatotoxic medication-related:
• Presence of clinically relevant liver disease
• Hepatic dysfunction as indicated by one or more of the following: i. Albumin ≤ 3.5 g/dL ii. Total bilirubin \> 1.5 x ULN and direct bilirubin ≥0.5 mg/dL iii. Alkaline phosphatase (ALP) \> 2 x ULN iv. Alanine transaminase (ALT) or aspartate transaminase (AST) \> 1.5 x ULN

Sponsors & Collaborators

• Sangamo Therapeutics: lead

Study Sites (11)

HonorHealth

Scottsdale, Arizona, 85260, United States

RECRUITING

University of Arkansas for Medical Sciences

Little Rock, Arkansas, 72205, United States

RECRUITING

The University of California, San Diego

La Jolla, California, 92093, United States

NOT YET RECRUITING

Johns Hopkins University

Baltimore, Maryland, 21218, United States

NOT YET RECRUITING

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

RECRUITING

Dartmouth Hitchcock Medical Center

Lebanon, New Hampshire, 03766, United States

NOT YET RECRUITING

Columbia University Irving Medical Center (CUIMC) and New York-Presbyterian Hospital (NYPH)

New York, New York, 10027, United States

RECRUITING

University of North Carolina Medical Center

Chapel Hill, North Carolina, 27514, United States

NOT YET RECRUITING

Vanderbilt University

Nashville, Tennessee, 37235, United States

NOT YET RECRUITING

University of Utah

Salt Lake City, Utah, 84112, United States

NOT YET RECRUITING

Virginia Commonwealth University

Richmond, Virginia, 23284, United States

RECRUITING

MeSH Terms

Conditions

Small Fiber Neuropathy

Interventions

salicylhydroxamic acid

Condition Hierarchy (Ancestors)

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases

Study Officials

• Medical Monitor

  Sangamo Therapeutics Inc.

  STUDY DIRECTOR

Central Study Contacts

Patient Advocacy

CONTACT

510-307-7266; clinicaltrials@sangamo.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: double-blind, randomized, sham-controlled dose escalation study

Study Record Dates

• First Submitted: April 30, 2025
• First Posted: May 20, 2025
• Study Start: December 4, 2025
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2028
• Last Updated: April 30, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (11)