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

A Phase 2 Randomized, Double-Blind, Placebo-Controlled, Multiple Ascending Dose Study of PGN-EDODM1 in Adult Participants With Myotonic Dystrophy Type 1 (FREEDOM2-DM1)

Status

Recruiting

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06667453

Acronym

FREEDOM2-DM1

Enrollment

Registered

2024-10-31

Start date

2024-12-10

Completion date

2027-03-01

Last updated

2026-07-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Myotonic Dystrophy 1

Keywords

DM1, Myotonic Dystrophy 1, Myotonic Dystrophy, PepGen, PGN-EDODM1, Myotonic Muscular Dystrophy, Steinert's Disease

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.

Interventions

DRUGPGN-EDODM1

Administered by intravenous (IV) infusion

OTHERPlacebo

Administered by intravenous (IV) infusion

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

16 Years to 65 Years

Healthy volunteers

Inclusion criteria

* Confirmed diagnosis of DM1, as defined as having a repeat sequence in the DMPK gene with at least 100 CTG repeats * Presence of myotonia * Have sufficient muscle mass in bilateral tibialis anterior (TA) muscles that a needle biopsy can safely be performed * Body Mass Index (BMI) of \< 35.0 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

Design outcomes

Primary

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

Secondary

Measure	Time frame	Description
Maximum Observed Plasma Drug Concentration (Cmax) of PGN-EDODM1	Day 1 through Day 84	—
Time to Maximum Observed Plasma Drug Concentration (Tmax) 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	—

Countries

Canada, New Zealand, South Korea, United Kingdom

Contacts

CONTACTPepGen

clinicaltrials@pepgen.com781-797-0979

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 30, 2026