Vertex tests long-term safety of VX-670 for muscle disease

NCT ID NCT06926621

ENROLLING_BY_INVITATION Disease control Sponsor: Vertex Pharmaceuticals Incorporated Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Aug 11, 2026 · Updated 4 times

Summary

This study tests the long-term safety and effectiveness of an experimental drug called VX-670 in adults with myotonic dystrophy type 1 (DM1). Participants who completed a previous VX-670 study can join. The drug is given through a vein, and researchers will monitor side effects and how the drug works in the body over time.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: VX-670 (given intravenously)
What this could lead to: If successful, this could support VX-670 as a long-term treatment to control myotonic dystrophy type 1 symptoms.
What could go wrong: This is an early Phase 2 extension study with only 44 participants, so results may not apply broadly. Long-term safety and effectiveness are still unproven.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

hereditary disease inherited neurodegenerative disorder muscle tissue disorder Muscular Disorders, Atrophic muscular dystrophy musculoskeletal system disorder Myotonia myotonic dystrophy myotonic dystrophy type 1 myotonic syndrome nervous system disorder neurodegenerative disease neuromuscular disease

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

MYOTONIC DYSTROPHY TYPE 1 (DM1)

Contacts and locations

Locations

Altasciences Montreal

Montreal, Canada
Friedrich Baur Institute

München, Germany
Hospital Universitario y Politecnico La Fe - Neurology

Valencia, Spain
Leonard Wolfson Experimental Neurology Centre CRF

London, United Kingdom
Maastricht UMC

Maastricht, Netherlands
Montreal Neurological Institute-Hospital

Montreal, Canada
Neuroscience Clinical Trials Unit, Alfred Brain

Melbourne, Australia
Queen Elizabeth University Hospital - Neurology

Glasgow, United Kingdom
Royal Hallamshire Hospital - Neurology

Sheffield, United Kingdom
St. Louis Children's Hospital - Neurology

St Louis, Missouri, 63110, United States
Universitaire Ziekenhuizen Leuven - Campus Gasthuisberg - Pulmonology

Leuven, Belgium
Universite Laval - Neurology

Québec, Canada
University of Ottawa

Ottawa, Canada
Virginia Commonwealth University - Sanger Hall

Richmond, Virginia, 23298, United States
Wesley Research Institute

Auchenflower, Australia

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