The Efficacy and Safety of Once Daily Mexiletine PR in Patients With Myotonic Dystrophy Type 1 and Type 2
NCT Number: NCT06523400
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: PHASE3
Conditions: Myotonic Dystrophy
Interventions: DRUG: Mexiletine granules for prolonged-release oral suspension|DRUG: Placebo
Sponsor: Lupin Ltd.
Collaborators: Lupin Atlantis Holdings S.A.
Sex: ALL
Age: CHILD, ADULT, OLDER_ADULT
Enrollment: 176
Study Design: Allocation: RANDOMIZED|Intervention Model: SINGLE_GROUP|Masking: NONE|Primary Purpose: TREATMENT
Start Date: 2024-09-27
Completion Date: 2026-04-22

Summary:
A Randomized, Double-blind, Placebo-Controlled, Multi-Center Study to Investigate the Efficacy and Safety of Once Daily Mexiletine PR During 26 Weeks of Treatment in Patients with Myotonic Dystrophy Type 1 and Type 2 (HERCULES study)

Primary Outcome Measures: To assess the efficacy of once daily mexiletine PR for the symptomatic treatment of myotonia in patients with myotonic dystrophy type 1 and type 2 (DM1 and DM2)., Handgrip relaxation time in DM1 patients by mean change in baseline of handgrip relaxation time (seconds) after maximal voluntary isometric contraction (MVIC), 26 weeks|To assess the safety of once daily mexiletine PR for the symptomatic treatment of myotonia in patients with myotonic dystrophy type 1 and type 2 (DM1 and DM2)., Number and frequency of AEs/SAEs throughout the study while on treatment, 26 weeks
Secondary Outcome Measures: Mean change in VAS, Score for muscle stiffness (myotonia severity) as self-reported by patients on a Visual Analog Scale (VAS), 26 weeks|Mean change in MBS scores, Mean change in Myotonia Behavior Scale (MBS) scores, 26 weeks|Mean change in health-related quality of life, Mean change in health-related quality of life (measured by INQoL), 26 weeks|Mean change in DM1-Activ-c scale (DM1 patients only), Mean change in measure of activity and social participation (measured by a Rasch-built scale with a 0-100 interval range), 26 weeks|Mean change in time to perform the 10-meter Walk Test, Mean change in time (seconds) to perform the 10-meter Walk Test (10mWT), 26 weeks|Mean change in handgrip relaxation time, Mean change in maximal voluntary isometric contraction (MVIC) and relaxation time by Video-recording of Hand Opening Time (VHOT) functional evaluation, 26 weeks|Mean change in time to perform Timed-up and go (TUG) test, Mean change in time (seconds) to perform Timed-up and go (TUG) test, 26 Weeks|Mean change in health-related quality of life measured by EQ-5D, Mean change in health-related quality of life measured by EQ-5D (5-point scale), 26 weeks|Mean change in Myotonic Dystrophy Health Index (MDHI) score (DM1 patients), Mean change in Myotonic Dystrophy Health Index (MDHI) score (DM1 patients) as measured by patient's perceived health, 26 weeks|Mean change in Myotonic Dystrophy 2 Health Index (MD2HI) score (DM2 patients), Mean change in Myotonic Dystrophy 2 Health Index (MDHI) score (DM2 patients) as measured by patient's perceived health, 26 weeks|Assess the safety of mexiletine PR by changes in ECG, Mean change in ECG (PR, QRS, QTc intervals, average HR) from baseline, 26 weeks|Assess the safety of mexiletine PR by AEs, Incidence of treatment emergent adverse events (TEAEs), treatment-related TEAEs, serious AEs, and patient discontinuation rate, 26 weeks|Assess the safety of mexiletine PR by standard clinical laboratory evaluations, Assess the safety of mexiletine PR by standard clinical laboratory evaluations as measured by hematology, chemistry, and urinalysis assessments from change in baseline, 26 weeks|Assess the safety of mexiletine PR by vital signs, Assess the safety of mexiletine PR by vital signs (pulse, respiration, body temperature, and blood pressure) from change in baseline, 26 weeks|Assess the safety of mexiletine PR by physical examinations, Assess the safety of mexiletine PR by change in baseline from physical examinations, 26 weeks|To assess the pharmacokinetics of mexiletine PR, To assess the pharmacokinetics of mexiletine PR as measured by PK parameter AUC0-t, 26 weeks|To assess the pharmacokinetics of mexiletine PR by AUC0-t, To assess the pharmacokinetics of mexiletine PR as measured by PK parameter AUC0-t (area under the concentration-time curve from time zero to last timepoint), 26 weeks|To assess the pharmacokinetics of mexiletine PR by Cmax, To assess the pharmacokinetics of mexiletine PR as measured by PK parameter Cmax (maximum plasma concentration), 26 weeks