RecruitingPhase 3

An Open-Label, Randomized, Cross-Over Study to Investigate the Efficacy and Safety of Mexiletine PR Compared to Mexiletine IR

Belgium24 participantsStarted 2025-09-03

Plain-language summary

An Open-Label, Randomized, Cross-Over Study to Investigate the Efficacy and Safety of Mexiletine PR compared to Mexiletine IR in Patients with Non-Dystrophic Myotonias (ACHILLES study)

Who can participate

Age range

16 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. 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);
. Non-dystrophic myotonias including myotonia congenita (MC), paramyotonia congenita (PC) and sodium channel myotonia (SCM) confirmed genetically;
. Male or non-pregnant female ≥16 years and older at screening;
. Body Mass Index (BMI) of 18.5 kg/m2 to 30 kg/m2, and weight ≥45 kg;
. Female patients of childbearing potential must be using a highly effective form of birth control for the duration of the study and for at least 30 days after last dose of study drug. Male patients must use birth control for the duration of the study and for at least 30 days after last dose of study drug;
. No significant cardiac abnormalities as determined by a cardiologist including electrocardiogram (ECG) and echocardiogram not older than 3 months prior to study entry;
. Participants with myotonic symptoms severe enough to justify treatment (in the opinion of the study investigator);
. Presence of clinical handgrip myotonia (delayed relaxation of grip of ≥ 3 second using a stopwatch) at screening (naïve patients only) and on Day 1 (pre-dose) (patients naïve and previously treated with mexiletine).

Exclusion criteria

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

To compare the safety of mexiletine PR vs mexiletine IR by incidence of treatment emergent Adverse Events (TEAEs), treatment-related TEAEs, serious AEs, and patient discontinuation rate between mexiletine PR and mexiletine IR after 12 weeks of treatment.

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in QTc intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in PR intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in QRS intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline by average minimum heart rate by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by performing physical examiniations

Timeframe: Baseline to week 24

Trial details

NCT IDNCT07097701

SponsorLupin Ltd.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-01-22

Contact for this trial

Nikki Adetoro

4434474534 nikkiadetoro@lupin.com

View on ClinicalTrials.gov More Myotonia trials

Who can participate

Age range

16 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. 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);
. Non-dystrophic myotonias including myotonia congenita (MC), paramyotonia congenita (PC) and sodium channel myotonia (SCM) confirmed genetically;
. Male or non-pregnant female ≥16 years and older at screening;
. Body Mass Index (BMI) of 18.5 kg/m2 to 30 kg/m2, and weight ≥45 kg;
. Female patients of childbearing potential must be using a highly effective form of birth control for the duration of the study and for at least 30 days after last dose of study drug. Male patients must use birth control for the duration of the study and for at least 30 days after last dose of study drug;
. No significant cardiac abnormalities as determined by a cardiologist including electrocardiogram (ECG) and echocardiogram not older than 3 months prior to study entry;
. Participants with myotonic symptoms severe enough to justify treatment (in the opinion of the study investigator);
. Presence of clinical handgrip myotonia (delayed relaxation of grip of ≥ 3 second using a stopwatch) at screening (naïve patients only) and on Day 1 (pre-dose) (patients naïve and previously treated with mexiletine).

Exclusion criteria

What they're measuring

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in QTc intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in PR intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline in QRS intervals by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by mean change from baseline by average minimum heart rate by12-lead in ECG

Timeframe: Baseline to week 24

To compare the safety of mexiletine PR vs mexiletine IR by performing physical examiniations

Timeframe: Baseline to week 24