Unknown Brain & Nervous System NIHR-supported project Heart, Stroke & Blood

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

Funder NIHR (part of DHSC)
Recipient organisation NIHR University College London Hospitals Biomedical Research Centre
NIHR support Recorded as supported by this research centre
Period Mar 2025 — Ongoing

In plain English

AI plain-English summary

People with myotonic dystrophy type 1 (DM1) cannot relax their contracted muscles, and no drug exists to treat the underlying cause of the disease. This study tests VX-670, an experimental drug designed to directly bind the genetic repeats that block normal cell function in DM1, in adults who previously received the drug in an earlier trial. DM1 affects at least 1 in 10,000 people worldwide, causing progressive muscle weakness, fatigue, swallowing difficulties, and problems with digestion, hormones, and reproduction. Current care only manages symptoms. VX-670 targets the root cause—expanded nucleotide repeats in the DMPK gene—by binding them and allowing normal protein function to resume. Over 24 weeks, researchers will collect safety data, measure symptom improvement through functional assessments and patient questionnaires, and analyse muscle biopsies to see whether the drug corrects the underlying biology. If successful, VX-670 could become the first disease-modifying treatment for DM1, potentially slowing or reversing muscle weakness and myotonia rather than just managing symptoms. This is an investigational drug given intravenously every six weeks, with dosing overseen by an independent safety committee.

View original technical description
Myotonic Dystrophy Type 1 (DM1) is a serious, progressive, & disabling disease affecting multiple body systems. Its clinical presentation varies among patients. Patient symptoms often include muscle weakness and myotonia (the inability to relax contracted muscles), as well as fatigue, excessive daytime sleepiness, swallowing, digestive, endocrine, & reproductive symptoms. Patient management options are limited to treating symptoms. There are no approved disease-modifying treatments for this disease. DM1 affects at least 1 in 10,000 people worldwide. DM1 is caused by a genetic variation in the DM1 protein kinase (DMPK) gene. This variation causes increased nucleotide repeats to block normal protein function in many cell types, including those that make up muscle tissue. VX-670, is designed to target the cause of DM1 by directly binding the increased nucleotide repeats in the DMPK transcript, allowing normal cell function to proceed. It is anticipated that overall muscle weakness and myotonia will improve in subjects treated with VX-670. This research study, VX24-670-101, is offered to subjects who took part in parent study VX23-670-001. The objective of study is to learn how safe, tolerable and effective multiple doses of VX-670 are in people with DM1. This will be accomplished through collection of participant safety data throughout the time of treatment. Symptom improvement will also be measured through various functional assessments and participant -reported outcome questionnaires (PROs). In addition, the effect of VX-670 on the biology that underlies all symptoms of DM1 will be evaluated by looking at muscle biopsies performed before the first dose (participants from parent Part A only) and again at study week 24 to accomplish this objective. VX-670 is investigational. It will be administered intravenously once every 6 weeks. Participant dose will be linked to that received in the parent study, with any changes overseen by an Independent Data Monitoring Committee

Researchers

Christopher Turner (Principal Investigator)

Related Research

Grants with similar aims, by meaning.

VX24-670-101 OLE - 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
A Phase 1/2, Randomized, Double-blind, Placebo-controlled Single- and Multiple-dose Escalation Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of VX-670 in Adult Subjects with Myotonic Dystrophy Type 1
Phase 1/2, Randomized, Double-blind, Placebo-controlled Single- and Multiple-dose Escalation Study Evaluating the Safety, Pharmacokinetics, and Pharmacodynamics of VX-670 in Adult Subjects with Myotonic Dystrophy Type 1.
VX23-670-001 - A Phase 1/2, Randomized, Double-blind, Placebo controlled Single- and Multiple dose Escalation Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of VX23-670 in Adult Subjects with Myotonic Dystrophy Type 1
Phase 1/2, Randomized, Double-blind, Placebo-controlled Single- and Multiple-dose Escalation Study Evaluating the Safety, Pharmacokinetics, and PharmacodyN/Amics of VX-670 in Adult Subjects with Myotonic Dystrophy Type 1.

Original classification

Translational Neuroscience

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