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Myotonic Dystrophy Type 1

Myotonic Dystrophy Type 1

Disease

Also known as: myotonic muscular dystrophy type 1

Disease Profile

Myotonic dystrophy type 1 is an autosomal dominant multisystem disorder caused by CTG repeat expansion in DMPK, characterized by myotonia, progressive muscle weakness, and systemic manifestations affecting cardiac, endocrine, and ocular systems.

Category: inherited neuromuscular disorder
Prevalence: Overall myotonic dystrophy prevalence is estimated at around 1 in 8,000 worldwide, with type 1 being the most common form.

Related News

Avidity's Myotonic Dystrophy Drug Shows Promising Phase 1/2 Trial Results

Mar 26, 2026

Avidity Biosciences announced promising Phase 1/2 trial results for its myotonic dystrophy type 1 drug delpacibart etedesiran, showing 40% reduction in DMPK mRNA and functional improvements. The therapy has received multiple regulatory designations and is now in Phase 3 testing with data expected in late 2026. The company's stock has surged 128% over the past year despite reporting a net loss of approximately $550 million.

Orphan Drug Designation Drives Rare Disease Therapy Development Across Global Markets

Mar 15, 2026

Regulatory incentives for rare disease treatments, including market exclusivity and development subsidies, are spurring pharmaceutical innovation across the US, Europe, Japan, and Australia, with multiple companies advancing therapies for conditions affecting limited patient populations.

Dyne Therapeutics Advances Neuromuscular Disease Programs Toward Commercialization

Mar 06, 2026

Dyne Therapeutics is preparing a U.S. Accelerated Approval submission for z-rostudirsen in Duchenne muscular dystrophy and gearing up for a Phase 3 trial of z-basivarsen in myotonic dystrophy, while scaling operations to support potential commercialization.

FDA Pauses U.S. Enrollment in Myotonic Dystrophy Trial After Serious Adverse Event

Mar 06, 2026

The FDA has placed a partial hold on U.S. enrollment in a Phase 2 trial of del-desiran for myotonic dystrophy type 1, citing preclinical mouse data showing blood pressure drops not seen in humans, following a serious adverse event in earlier testing.

FDA Places Partial Clinical Hold on PepGen's FREEDOM2-DM1 Trial

Mar 05, 2026

The FDA has placed a partial clinical hold on PepGen's Phase 2 FREEDOM2-DM1 trial for myotonic dystrophy type 1, citing questions about preclinical pharmacology and toxicology studies. The company is submitting additional analyses to address the FDA's concerns.

Del-desiran Shows Muscle Delivery and Splicing Improvements in Phase 1/2 DM1 Trial

Feb 19, 2026

Phase 1/2 MARINA trial results published in NEJM show del-desiran achieved approximately 40% reduction in toxic DMPK mRNA in muscle tissue and improvements in myotonia and functional measures in myotonic dystrophy type 1 patients, with acceptable safety profile.

Dyne Therapeutics Receives Orphan Drug Designation in Japan for DM1 Treatment

Feb 17, 2026

Japan's Ministry of Health, Labour and Welfare granted Orphan Drug designation to Dyne Therapeutics' investigational treatment zeleciment-basivarsen for myotonic muscular dystrophy type 1, adding to existing designations in the U.S. and Europe.

Related Clinical Trials

NCT ID	Title	Status	Phase
NCT07493525	Fall Frequency and Factors Affecting Dynamic Balance in Patients With Myotonic Dystrophy Type 1	ACTIVE_NOT_RECRUITING
NCT07385443	The Spanish National Registry for Myotonic Dystrophy Type 1	RECRUITING
NCT07008469	Global Open-Label Extension Study of Del-desiran for the Treatment of DM1	ENROLLING_BY_INVITATION	PHASE3
NCT06809049	Music Intervention for Brain-Heart Disease in Myotonic Dystrophy Type 1 (DM1)	RECRUITING	NA
NCT06596850	Wheelchair Skills Training for People with ARSACS and DM1	NOT_YET_RECRUITING	NA
NCT06316778	Pelvic Floor Muscle Training for Women with Myotonic Dystrophy	RECRUITING	NA
NCT06075693	Cerebrospinal Fluid Biomarkers of Myotonic Dystrophy	RECRUITING
NCT05916677	Virtual Reality-training in Theory of Mind in the Childhood Form of Myotonic Dystrophy Type 1	ENROLLING_BY_INVITATION	NA
NCT05854433	Brain Structure and Clinical Endpoints in Myotonic Dystrophy Type 2	RECRUITING
NCT02831504	PhenoDM1 (Myotonic Dystrophy Type 1 Natural History Study)	COMPLETED