Table 1. Summary of Therapeutic Development and Clinical Stages for Myotonic Dystrophy Type 1

Company	Drug	Modality	Phase	Key findings or status
AMO pharma ltd	Tideglusib	Small molecule	Phase 2/3	The phase 2/3 REACH-CDM trial in congenital myotonic dystrophy type 1 did not demonstrate definitive clinical efficacy.
Avidity biosciences	AOC 1001 (Del-desiran)	Antibody-conjugated siRNA	Phase 3 ongoing	The phase 1/2 MARINA trial showed -45% reduction in DMPK expression and improvement in mis-splicing. Based on these results, the phase 3 HARBOR trial is underway.
Lupin neurosciences	Mexiletine	Small molecule	Phase 3 ongoing	Demonstrated significant reduction in hand-grip relaxation time and EMG myotonia, but no evidence of slowing disease progression. The phase 3 HERCULES trial is ongoing.
Academia-led	Metformin	Biguanide	Phase 3 ongoing	Phase 2 studies reported statistically significant improvement in walking distance versus placebo. Phase 3 studies are ongoing or planned, but no official results have been released.
Harmony biosciences	Pitolisant	Small molecule	Phase 2	Phase 2 data demonstrated improvement in excessive daytime sleepiness and fatigue.
Dyne therapeutics	DYNE-101	Antibody fragment–conjugated antisense oligonucleotide	Preparing for Phase 3	Phase 1/2 ACHIEVE data showed 25-40% splicing correction and improvement in myotonia. A phase 3 trial is in preparation.
ARTHEx biotech	ATX-01	Antisense microRNA oligonucleotide	Phase 1/2	Targets miR-23b, which regulates MBNL protein expression. Phase 1/2 studies are ongoing.
PepGen	PGN-EDODM1	Peptide-conjugated antisense oligonucleotide	Phase 1	The phase 1 FREEDOM-DM1 trial demonstrated safety and improvement in muscle mis-splicing. A phase 2 trial (FREEDOM2-DM1) is ongoing.
Vertex	VX-670	Peptide-conjugated oligonucleotide	Phase 1/2	Designed to directly target CTG repeats within the DMPK transcript to correct spliceopathy. Phase 1/2 trials are ongoing.
Sarepta	SRP-1003	siRNA-mediated RNA interference	Phase 1/2a	siRNA therapy targeting CUG-expanded RNA to induce degradation or reduce expression. Phase 1/2a studies are ongoing.
Juvena therapeutics	JUV-161	Stem cell-secreted protein therapeutic	Phase 1	AI-screened fusion protein derived from human stem-cell secretome. A phase 1 study in healthy volunteers began in May 2025.
IONIS	Baliforsen (ISIS 598769)	Antisense oligonucleotide	Phase 1/2a	Early trials showed acceptable safety but insufficient intramuscular drug levels. Further development was discontinued.