An Observational Study to Describe the Long-term Safety and Effectiveness of Namuscla in the Symptomatic Management of Myotonia in Adult Patients with Non-dystrophic Myotonic Disorders

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Effectiveness study (incl. comparative)

  Evaluation of patient-reported outcomes

  Safety study (incl. comparative)
• Data collection methods:
  Primary data collection

Non-interventional study

• Non-interventional study design:
  Other
• Non-interventional study design, other:
  Non-interventional Prospective Post Authorisation Safety Study (PASS)

Study drug and medical condition

• Medicinal product name:
  NAMUSCLA
• Study drug International non-proprietary name (INN) or common name:
  MEXILETINE HYDROCHLORIDE
• Anatomical Therapeutic Chemical (ATC) code:
  (C01BB02) mexiletine

  mexiletine
• Medical condition to be studied:
  Myotonia

Population studied

• Short description of the study population:
  The study population will comprise patients who are diagnosed with non-dystrophic myotonic disorders and considered suitable candidates for the treatment by Namuscla by the investigators according to the approved SmPC and who meet the eligibility criteria.This includes: ; 1. Patients newly initiated on Namuscla for the treatment of NDM (newly exposed); 2. Patients already on Namuscla/ mexiletine at enrolment - For patients receiving mexiletine other than Namuscla, only those who switch to Namuscla will be included in the study.; ; Patients already being treated with Namuscla/ mexiletine at the time of enrolment will be considered for enrolment provided they meet the eligibility criteria.
• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Special population of interest:
  Hepatic impaired

  Immunocompromised

  Renal impaired
• Estimated number of subjects:
  50

Study design details

• Study design:
  This is a non-interventional, prospective, observational, multicentre study
• Main study objective:
  Primary Objective: To describe the long-term safety and tolerability of Namuscla for the symptomatic treatment of myotonia in adult patients with non-dystrophic myotonic disorders.
• Setting:
  The study will be conducted at specialized centres for the treatment of myotonic disorders that see at least 20-30 patients annually (“reference centres”).
• Outcomes:
  Outcome Variables: Primary: 1. Proportion of patients with treatment-emergent AEs (TEAEs, including SAEs) from study enrolment to 6, 12, 24 and 36 months on Namuscla, 2. Proportion of patients requiring dose reduction or treatment discontinuation due to AEs (including SAEs). Safety:1Proportion of pts with AEs/SAEs/AESI from study enrolment to 6,12,24,and 36 months.2. Proportion of AEs in pts with abnormal hepatic function 3.Number of AEs in pts with abnormal renal function 4.Number of AEs in geriatric pts 5.Number of pts with cardiac arrhythmia,SCAR,DRESS,SJS,seizures.Efficacy:6.Change VAS,stiffness,fatigue7.Clinical myotonia evaluation8.Change INQoL&MBS.
• Data analysis plan:
  All statistical analyses will be performed using SAS® Version 9.4 or higher.Data will be presented by myotonic disorder type, by age group (18 to 64 years, inclusive, and ≥65 years), other subgroups of interest, and by Namuscla use (newly exposed and prior mexiletine exposure, average dose). Standard descriptive summaries: Descriptive statistics for continuous data: The continuous data will be summarized using the number of observations (n), arithmetic mean, standard deviation, median, minimum value, maximum value and 95% CI. The (n) will be presented with no decimal place, mean and median will be presented up to one decimal place from the original value, SD up to two decimal places from the original value and (min, max) as an original value. Descriptive statistics for categorical data: The categorical variables will be summarized using the frequency count & % for each possible value. The frequencies will be presented up to 0 decimal places and % up to 1 decimal place.