A Clinical Study of PGN-EDODM1 in People With Myotonic Dystrophy Type 1

Phase 2

Recruiting

• Conditions: Myotonic Dystrophy 1
• Interventions: Drug: PGN-EDODM1; Other: Placebo

• Registration Number: NCT06667453
• Lead Sponsor: PepGen Inc

Brief Summary

The purpose of this study is to learn about the effects of an investigational medicine, PGN-EDODM1, to see how safe and tolerable multiple administrations of PGN-EDODM1 are for people with myotonic dystrophy type 1 (DM1) compared to placebo.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2024-10-22
• Study First Submitted QC: 2024-10-29
• Study First Posted: 2024-10-31
• Study Start: 2024-12-10
• Status Verified: 2025-08
• Last Update Submitted: 2025-08-13
• Last Update Posted: 2025-08-17
• Primary Completion: 2026-08
• Study Completion: 2026-08-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 24

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
• Body Mass Index (BMI) of < 32.0 kg/m^2

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 considered clinically significant by the Investigator
• Medications specific for the treatment of myotonia within 2 weeks prior to screening
• Percent predicted forced vital capacity (FVC) <40%
• Use of an investigational drug, device, or product within 30 days of 5 half-lives of the study drug (whichever is longer) prior to Screening

Note: Other inclusion and exclusion criteria may apply.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
PGN-EDODM1	PGN-EDODM1	Participants will be randomized to receive ascending doses of PGN-EDODM1, once every 4 weeks (Q4W) for 12 weeks
Placebo	Placebo	Participants randomized to the placebo arm will receive doses of saline (0.9% NaCl), once every 4 weeks (Q4W) for 12 weeks

Primary Outcome Measures

Name	Time	Method
Safety and tolerability as assessed by number of participants with Adverse Events (AEs)	Baseline through Day 112

Secondary Outcome Measures

Name	Time	Method
Time to Maximum Observed Plasma Drug Concentration (Tmax) of PGN-EDODM1	Day 1 through Day 84
Maximum Observed Plasma Drug Concentration (Cmax) of PGN-EDODM1	Day 1 through Day 84
Apparent Terminal Half-Life (t½) of PGN-EDODM1	Day 1 through Day 84
Area Under the Concentration-time Curve of PGN-EDODM1	Day 1 through Day 84
Change in splicing index in skeletal muscle tissue	Baseline through Day 91
Change in myotonia as measured by video Hand Opening Time (vHOT)	Baseline through Day 112
Hand grip strength	Baseline through Day 112	by dynamometer
Change in mobility as measured by 10 meter walk/run time	Baseline through Day 112

Trial Locations

Locations (6)

University of Calgary; 🇨🇦 Calgary, Alberta, Canada

Ottawa Hospital Research Institute (OHRI); 🇨🇦 Ottawa, Ontario, Canada

CIUSSS du Saguenay-Lac-Saint-Jean; 🇨🇦 Chicoutimi, Quebec, Canada

Montreal Neurological Institute; 🇨🇦 Montréal, Quebec, Canada

University College London Hospitals NHS Foundation Trust; 🇬🇧 London, UK, United Kingdom

Newcastle Upon Tyne Hospitals; 🇬🇧 Newcastle Upon Tyne, United Kingdom