Recruiting
Phase 1
Phase 2

SRP-1003

Sponsor:

Sarepta Therapeutics, Inc.

Code:

NCT06138743

Conditions

Myotonic Dystrophy 1

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

SRP-1003 IV Infusion

Placebo IV Infusion

SRP-1003 SC Injection

Placebo SC Injection

Study Details

Brief summary:

This is a phase 1/2a double-blinded, placebo-controlled, dose-escalating study to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of single and multiple ascending doses of SRP-1003 compared to placebo in male and female participants with type 1 myotonic dystrophy (DM1). Participants who have provided written informed consent and met all protocol eligibility requirements will be randomized to receive single (Part 1) or multiple (Part 2) doses of SRP-1003 or placebo.

Conditions

Myotonic Dystrophy 1

Study ID

NCT06138743

Start date

Mar 4, 2024

Status verified date

Aug, 2026

Completion date

Dec 31, 2026

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Genetically confirmed diagnosis of DM1
  • Clinician-assessed signs of DM1 including clinically apparent myotonia
  • Onset of DM1 symptoms occurred after the age of 12 years
  • Walk for at least 10 meters independently at screening
  • Participants of childbearing potential must agree to use highly effective contraception in addition to a condom during the study and for at least 90 days following the end of study or last dose of study drug, whichever is later. Participants must not donate sperm or eggs during the study and for at least 90 days following the end of study or last dose of study drug whichever is later.

Key Exclusion Criteria:

  • Inadequately controlled diabetes
  • Confirmed diagnosis of congenital DM1
  • Uncontrolled hypertension
  • History of tibialis anterior (TA) biopsy within 3 months of Day 1 or planning to undergo TA biopsies during the study period
  • Clinically significant cardiac, liver or renal disease
  • Human immunodeficiency virus infection (seropositive) at screening
  • Seropositive for hepatitis B or hepatitis C at screening
  • Untreated or poorly controlled epilepsy
  • Treatment with anti-myotonia medication within a period of 5 half-lives of the medication prior to screening.
  • Abnormal coagulation parameters at screening including platelet count, international normalized ratio, prothrombin time, and activated partial thromboplastin time

Note: Additional inclusion/exclusion criteria may apply per protocol

Study Design

Enrollment

78 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: SRP-1003 IV Infusion

Single or multiple doses of SRP-1003 by intravenous (IV) infusion

placebo comparator: Placebo by IV Infusion

Single or multiple doses of placebo by IV infusion

experimental: SRP-1003 SC Injection

Single or multiple doses of SRP-1003 by subcutaneous (SC) injection

placebo comparator: Placebo by SC Injection

Single or multiple doses of placebo by SC injection

Interventions

SRP-1003 IV Infusion

SRP-1003 by IV infusion

Placebo IV Infusion

0.9% sodium chloride (NaCl) calculated volume to match active treatment by IV infusion

SRP-1003 SC Injection

SRP-1003 by SC injection(s)

Placebo SC Injection

0.9% NaCl calculated volume to match active treatment by SC injection(s)

Primary outcome measure

  • Number of Participants with Treatment-emergent Adverse Events Over Time Through End of Study (EOS) [ Time Frame: Single-dose phase (Part 1): Up to Day 90 (EOS); multiple-dose phase (Part 2): Up to Day 180 (EOS) ]

Central Contacts and Locations

Central contacts

Sarepta Therapeutics Inc. For Clinical Trial Information, Select Option 4

1-888-SAREPTA (1-888-727-3782)SareptAlly@sarepta.com

Locations

University Of Calgary

Recruiting

Calgary, Canada

University Of Alberta

Recruiting

Edmonton, Canada

McGill University

Recruiting

Montreal, Canada

More Information

Sponsor

Sarepta Therapeutics, Inc.

Last update posted

Aug 11, 2026

Last verified

Aug, 2026

Keywords

  • Myotonic Dystrophy 1
  • SRP-1003
  • ARO-DM1

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Sarepta Therapeutics, Inc. on 2026-08-11.