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

  • Research type

    Research Study

  • Full 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

  • IRAS ID

    1011219

  • Contact name

    Jinesh Patel

  • Contact email

    jinesh_patel@vrtx.com

  • Sponsor organisation

    Vertex Pharmaceuticals Inc.

  • Eudract number

    2024-517983-47

  • ISRCTN Number

    --

  • Research summary

    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

  • REC name

    South Central - Oxford A Research Ethics Committee

  • REC reference

    25/SC/0030

  • Date of REC Opinion

    5 Mar 2025

  • REC opinion

    Further Information Favourable Opinion