Study of SRP-1001 in Adult and Adolescent Participants With Facioscapulohumeral Muscular Dystrophy Type 1

August 7, 2026 updated by: Sarepta Therapeutics, Inc.

A Phase 1/2a Dose-Escalating Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of ARO-DUX4 (SRP-1001) in Adult Patients and Adolescent Patients With Facioscapulohumeral Muscular Dystrophy Type 1

The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of SRP-1001 in participants with facioscapulohumeral muscular dystrophy Type 1 (FSHD1). In Part 1 of the study, participants will receive one dose of SRP-1001 or placebo. In Part 2 of the study, participants will receive 4 doses of SRP-1001 or placebo. Participants who complete Part 1 will have the option to re-screen and re-randomize into Part 2. All participants will undergo pre- and post-dose magnetic imaging resonance (MRI)-guided muscle biopsies (a total of 2 biopsies). Participants who complete Part 1 and enroll in Part 2 will be required to undergo an additional screening biopsy. Participants completing Part 1 or Part 2 may have the option to continue to receive drug in an open-label extension study or may be eligible to participate in later-stage clinical studies.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Sarepta Therapeutics Inc. For Clinical Trial Information, Select Option 4
  • Phone Number: 1-888-SAREPTA (1-888-727-3782)
  • Email: SareptAlly@sarepta.com

Study Locations

    • New South Wales
      • Liverpool, New South Wales, Australia, 2170
        • Recruiting
        • Liverpool Hospital
    • Queensland
      • Auchenflower, Queensland, Australia, 4066
        • Recruiting
        • Wesley Research Institute
      • Birtinya, Queensland, Australia, 4575
        • Recruiting
        • Sunshine Coast University Hospital
    • Victoria
      • Melbourne, Victoria, Australia, 3004
        • Recruiting
        • Alfred Health
    • Alberta
      • Calgary, Alberta, Canada, T2N4Z6
        • Not yet recruiting
        • University Of Calgary
      • Edmonton, Alberta, Canada, T6G2G4
        • Recruiting
        • University of Alberta
    • Quebec
      • Montreal, Quebec, Canada, H3A2B4
        • Recruiting
        • McGill University
      • München, Germany, 80336
        • Recruiting
        • Universitätsklinikum München
      • Ulm, Germany, 89081
        • Recruiting
        • Neurologische Universitätsklinik Am Rku
      • Milan, Italy, 20162
        • Recruiting
        • Centro Clinico Nemo Milann
      • Roma, Italy, 00168
        • Recruiting
        • Fondazione Policlinico Universitario A. Gemelli
      • Leiden, Netherlands, 2333
        • Recruiting
        • Centre For Human Drug Research
      • Auckland, New Zealand, 1010
        • Recruiting
        • New Zealand Clinical Research
      • Barcelona, Spain, 08035
        • Recruiting
        • Hospital Universitario Vall d'Hebron
      • Madrid, Spain, 28034
        • Recruiting
        • Hospital Universitario Ramon Y Cajal
      • Valencia, Spain, 46026
        • Recruiting
        • Hospital Universitari l Politecnic La Fe de Valencia

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Genetically confirmed FSHD1 based on screening evaluation or source verifiable medical record
  • Clinical severity score between 3 and 8 (scale, 0 to 10)
  • Must have an eligible lower extremity muscle for biopsy as determined from MRI by a central reader, with muscle fat fraction ≥10% and less than approximately 40%
  • Males or nonpregnant, nonlactating females ≥18 years of age who do not plan to become pregnant during the study, with an upper age limit of ≤70 years
  • Able and willing to provide written informed consent prior to the performance of any study specific procedures
  • Participants with a body mass index (BMI) between 18.0 and 35.0 kilograms/square meter, inclusive. A participant with FSHD1 and a BMI outside this range may be allowed into the study at the discretion of the principal investigator.
  • Must have eligible lower extremity muscle for biopsy as determined from MRI by a central reader
  • A 12-lead electrocardiogram at screening with no abnormalities that may compromise participant's safety in the study
  • Participants of childbearing potential and their partners must use highly effective contraception during the study and for at least 9 months following the end of study or last dose of study medication, whichever is later. Males must not donate sperm during the study from Day 1 until at least 9 months following the end of study or last dose of study medication, whichever is later.

Key Exclusion Criteria:

  • Human immunodeficiency virus (HIV) infection as shown by presence of anti-HIV antibody (seropositive) at screening
  • Seropositive for hepatitis B or hepatitis C at screening
  • Uncontrolled hypertension
  • Severe cardiovascular disease
  • History of thrombolic events
  • Platelet count less that the lower limit of normal at screening
  • History or presence of: a hypercoagulable state, nephrotic range proteinuria, antiphospholipid antibody syndrome, myeloproliferative disease, inability to ambulate, use of hormone-based contraceptives.
  • Any contraindication to muscle biopsy or MRI

Note: additional inclusion/exclusion criteria may apply per protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SRP-1001
SRP-1001 for injection
Single or multiple doses of SRP-1001 by intravenous (IV) infusion
Other Names:
  • ARO-DUX4 for Injection
Placebo Comparator: Placebo
Sodium chloride (0.9%)
Calculated volume to match active treatment by IV infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Number of Participants With Treatment-Emergent Adverse Events Over Time Through End of Study
Time Frame: Part 1: Up to Day 90; Part 2: Up to Day 360
Part 1: Up to Day 90; Part 2: Up to Day 360

Secondary Outcome Measures

Outcome Measure
Time Frame
PK of SRP-1001: Maximum Observed Plasma Concentration (Cmax)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Area Under the Plasma Concentration Versus Time Curve from Zero to 24 Hours (AUC0-24)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Area Under the Plasma Concentration Versus Time Curve from Zero to the Last Quantifiable Plasma Concentration (AUClast)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Area Under the Plasma Concentration Versus Time from Zero to Infinity (AUCinf)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Terminal Elimination Half-Life (t1/2)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Systemic Clearance (CL)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Volume of Distribution (Vss)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Recovery of Unchanged Drug in Urine Over 0-24 Hours (Amount Excreted: Ae)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Fraction of Drug Excreted in Urine as Percent of IV Dose (Fe)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
PK of SRP-1001: Renal Clearance (CLr)
Time Frame: Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose
Part 1: through 48 hours post-dose (all cohorts) and through 48 hours post second dose (Cohorts 3 & 4 only); Part 2: through 8 hours post first and second dose

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Study Director: Medical Director, Sarepta Therapeutics, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 19, 2024

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

November 8, 2023

First Submitted That Met QC Criteria

November 13, 2023

First Posted (Actual)

November 15, 2023

Study Record Updates

Last Update Posted (Actual)

August 11, 2026

Last Update Submitted That Met QC Criteria

August 7, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • SRP-1001-101
  • 2023-509748-89-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.