PepGen reports early trial data for myotonic dystrophy type 1 candidate PGN-EDO-DM1

PepGen, a biotechnology company developing peptide-conjugated antisense oligonucleotide therapies, has released early clinical trial data for its candidate PGN-EDO-DM1 in myotonic dystrophy type 1 (DM1), according to reporting by STAT News on 10 November 2026.

DM1 is caused by an expanded CTG repeat in the DMPK gene. The expanded repeat RNA sequesters muscleblind-like (MBNL) splicing regulators in nuclear foci, causing widespread alternative splicing defects across multiple tissues. PepGen's approach uses a cell-penetrating peptide conjugated to an antisense oligonucleotide designed to target the pathological repeat RNA and correct downstream splicing errors — a strategy sometimes described as correcting the "genetic stutter" at the RNA level.

STAT News characterised the early data as promising, with the company reporting evidence that the drug is correcting more splicing defects than previously observed. DM1 is the most common form of adult muscular dystrophy and has no approved disease-modifying therapy; multiple groups are pursuing RNA-targeting strategies given the well-defined molecular pathology. The trial remains at an early stage, and larger studies with functional endpoints will be required to establish clinical benefit. The reporting did not specify the trial phase, patient numbers, or the specific biomarkers used to assess splicing correction.