The Efficacy and Safety of Once Daily Mexiletine PR in Patients With Myotonic Dystrophy Type 1 and Type 2

ConditionMyotonic Dystrophy

Trial statusRecruiting

Trial phasePhase 3

Trial typeInterventional

Biological sexAll

Age16+

SponsorLupin Ltd.

About this trial

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)

Study website: https://myotonicdystrophystudy.com/

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

DM1 or DM2 diagnosis confirmed genetically;

Ability to comprehend and willingness to sign an informed consent (ICF) or ICF of the parent(s)/legal guardian and written assent from the patient (if patient < 18 years of age);

Ability to understand the study requirements including intention to stay in the study until the end-of-study visit at 26 weeks of treatment;

Male or non-pregnant female ≥16 years of age;

Disqualifiers

Are pregnant or lactating;

Have any one of the following medical conditions: uncontrolled diabetes mellitus, cancer other than skin cancer less than five years previously (e.g., basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC) of skin allowed), multiple sclerosis, seizure disorders, or other serious medical illness;

Severe renal impairment (glomerular filtration rate (GFR) < 30 mL/min);

Medical conditions which could interfere with muscle function such as infections, trauma, fractures, or planned surgery;

Trial design

Design model

Single group

Treatments tested in this trial

Mexiletine granules for prolonged-release oral suspension
Drug
Mexiletine PR
Placebo
Drug
Matching Placebo

Treatment groups

176 Participants

are divided into 2 treatment groups

Group A: PlaceboPlacebo comparator 1 intervention

Group B: Mexiletine prolonged-release (PR)Active comparator 1 intervention

Trial outcomes

Primary outcomes

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)

Time frame

26 weeks

Secondary outcomes

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

Time frame

26 weeks

Mean change in VAS

Score for muscle stiffness (myotonia severity) as self-reported by patients on a Visual Analog Scale (VAS)

Time frame

26 weeks

Mean change in MBS scores

Mean change in Myotonia Behavior Scale (MBS) scores

Time frame

26 weeks

Mean change in health-related quality of life