Clinical Trial Update: Early Results Published for DM1 Investigational Therapy

Pharmaceutical company PepGen has published preliminary results from the first phase of its FREEDOM2-DM1 clinical trial, which is investigating a potential new therapy for people living with myotonic dystrophy type 1 (DM1).

The trial is evaluating PGN-EDODM1, an investigational treatment. The first cohort of eight participants — six receiving the therapy and two receiving a placebo — showed that the treatment was generally well-tolerated, with side effects described as mild or moderate. A positive trend was observed in a hand movement test used to measure myotonia, though no significant changes were recorded in walking speed or handgrip strength at this early stage. Results on the therapy's effect on the underlying biology of DM1 were mixed in this initial cohort.

The trial is continuing to enrol participants in the United Kingdom and Canada, with new sites recently approved in New Zealand, South Korea and Australia. Data from the second cohort, which will test a higher dose, is expected in the second half of 2026.

It is important to note that PGN-EDODM1 remains an investigational therapy and has not been approved for use in any country. These are early-stage results, and further data from subsequent cohorts will be needed before any conclusions can be drawn about its safety and effectiveness.

PepGen has also noted that the trial is currently on a partial clinical hold in the United States, relating to questions raised by the FDA about non-human studies. This does not affect the ongoing trial in other countries, and PepGen has confirmed it is working to resolve the matter.

For more information or to read the full community letter from PepGen: Click here.