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 Adults With Myotonic Dystrophy Type 1

What this Trial Is About

Researchers are evaluating the safety, tolerability, and how the body processes and responds to VX-670 in adults with Myotonic Dystrophy Type 1 (DM1). This study is a Phase 1/2 trial that compares different doses of VX-670 to placebo in people diagnosed with DM1 who have a confirmed genetic test showing a specific repeat in their DNA. Participants will be randomly assigned to receive either single or multiple doses of VX-670 or matching placebo. The study has two parts: Part A focuses on single ascending doses, while Part B includes both single and multiple ascending doses. The dosing levels in Part B will be based on results from Part A. Both VX-670 and placebo are given as intravenous solutions. During the study, participants will be monitored for adverse events up to 42 days in Part A and 168 days in Part B to assess safety and tolerability. Researchers will measure drug concentrations in blood plasma and muscle at various time points, including baseline, days 15, and 120. Muscle biopsies will be used to analyze changes in gene splicing. The total participation duration varies by study part, with detailed monitoring of drug effects and safety throughout.

A Phase 1/2 Study of VX-670 in Adult Participants With Myotonic Dystrophy 1 (DM1)