Safety, Tolerability, PK, and PD Study of PGN-EDODM1 in Participants With Myotonic Dystrophy Type 1 (FREEDOM-DM1)

February 12, 2026 updated by: PepGen Inc

A Phase 1 Placebo-Controlled Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single-Ascending Doses of PGN-EDODM1 in Adult Participants With Myotonic Dystrophy Type 1 (FREEDOM-DM1)

The primary purpose of the study is to evaluate the safety and tolerability of single intravenous (IV) doses of PGN-EDODM1 administered to participants with Myotonic Dystrophy Type 1 (DM1).

The study consists of 2 periods: A Screening Period (up to 30 days) and a Treatment and Observation Period (16 weeks).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

24

Phase

  • 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 Locations

  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T3M 1M4
        • University Of Calgary
    • Ontario
      • Ottawa, Ontario, Canada
        • Ottawa Hospital Research Institute (OHRI)
    • Quebec
      • Chicoutimi, Quebec, Canada
        • CIUSSS du Saguenay-Lac-Saint-Jean
  • United Kingdom
      • Salford, United Kingdom
        • Salford Royal Hospital
    • UK
      • London, UK, United Kingdom, NW1 2PG
        • University College London Hospital
  • United States
    • California
      • Irvine, California, United States, 92697
        • UCI Center for Clinical Research
      • Palo Alto, California, United States, 94304
        • Stanford University
    • Georgia
      • Atlanta, Georgia, United States, 30329
        • Rare Disease Research
    • Kansas
      • Fairway, Kansas, United States, 66205
        • University of Kansas Medical Center
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
    • New York
      • Rochester, New York, United States, 14642
        • University of Rochester Medical Center
    • Virginia
      • Richmond, Virginia, United States, 23298
        • Virginia Commonwealth University

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Confirmed diagnosis of DM1, as defined as having a repeat sequence in the DMPK gene with at least 100 CTG repeats
  • Medical Research Council (MRC) score of ≥ Grade 4- in bilateral tibialis anterior (TA) muscles (the ability to move through full range of motion and hold against at least moderate pressure from the examiner)
  • Presence of myotonia

Exclusion Criteria:

  • Congenital DM1
  • Known history or presence of any clinically significant conditions that may interfere with study safety assessments
  • Abnormal laboratory tests at screening
  • Medications specific for the treatment of myotonia within 2 weeks prior to screening
  • Percent predicted forced vital capacity (FVC) <40%

Note: Other inclusion and exclusion criteria may apply.

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: PGN-EDODM1
PGN-EDODM1 for infusion
Drug: PGN-EDODM1 for infusion
Single dose of PGN-EDODM1 by intravenous (IV) infusion
Placebo Comparator: Placebo
0.9% NaCl
Other: Placebo
Administered by IV infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Number of participants with Adverse Events, Serious Adverse Events, with abnormal Clinical Laboratory tests, abnormal ECGs, and abnormal Vital Signs
Time Frame: Baseline to Week 16
Baseline to Week 16

Secondary Outcome Measures

Outcome Measure
Time Frame
Maximum Observed Plasma Drug Concentration (Cmax) of PGN-EDODM1
Time Frame: Baseline up to Day 3
Baseline up to Day 3
Time to Maximum Observed Plasma Drug Concentration (Tmax) of PGN-EDODM1
Time Frame: Baseline up to Day 3
Baseline up to Day 3
Apparent Terminal Half-Life (t½) of PGN-EDODM1
Time Frame: Baseline up to Day 3
Baseline up to Day 3
Area Under the Concentration-time Curve of PGN-EDODM1
Time Frame: Baseline up to Day 3
Baseline up to Day 3

Collaborators and Investigators

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

Sponsor

PepGen 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)

December 12, 2023

Primary Completion (Actual)

October 28, 2025

Study Completion (Actual)

October 28, 2025

Study Registration Dates

First Submitted

December 5, 2023

First Submitted That Met QC Criteria

January 3, 2024

First Posted (Actual)

January 12, 2024

Study Record Updates

Last Update Posted (Actual)

February 13, 2026

Last Update Submitted That Met QC Criteria

February 12, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PGN-EDODM1-101

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.

No

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.

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