Early access
Sign in
Enrolling by invitationPhase 2

A Study of Long-term Safety and Efficacy of VX-670 in Participants With Myotonic Dystrophy Type I

Key facts

Who runs it
Vertex Pharmaceuticals Incorporated
Where
Richmond, St Louis, and Winston-Salem, United StatesSee the 3 sitesAlso in 9 other countries, 15 sites
Status
Enrolling by invitation
Phase
Phase 2
People taking part
44 people, planned
Started
28 Apr 2025
Expected to end
30 Jan 2029
Type of study
Interventional
Treatments tested
  • VX-670
Record updated
14 October 2026

Who can take part

Age
18 years to 64 years
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 2 criteriaShow less

Who can take part

  • Completed study drug treatment in parent study VX23-670-001 (NCT06185764)

Who cannot take part

  • History of any illness or any clinical condition as pre-specified in the protocol; Other protocol defined Inclusion/Exclusion criteria may apply

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 64 years old?

Where in United States

Also in 9 other countries, 15 sites

  • Virginia Commonwealth University - Sanger HallRichmond, United StatesEnrolling by invitation
  • St. Louis Children's Hospital - NeurologySt Louis, United StatesEnrolling by invitation
  • Wake Forest Univ School of Medicine - NeurologyWinston-Salem, United StatesEnrolling by invitation

About the trial

What the trial wants to find out

The purpose of the study is to evaluate the long-term safety and tolerability, efficacy and pharmacokinetics of VX-670 in participants with Myotonic Dystrophy Type I (DM1).

The group in the trial

  • VX-670Treatment being tested

    Participants will receive multiple doses of VX-670.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
An Open-label Extension Study Evaluating the Long-term Safety, Tolerability, Efficacy, Pharmacokinetics, and Pharmacodynamics of VX-670 in Adult Subjects With Myotonic Dystrophy Type I
Fit questions
Built from NCT06926621, who can take part
Record updated
14 October 2026