EMA has approved Lupin’s NaMuscla (mexiletine) for children aged 6–11 years with non-dystrophic myotonic disorders and added new 62 mg and 83 mg capsule strengths, expanding treatment options across Europe.
Written By: Disha Jadhao, BPharm
Reviewed By: Pharmacally Editorial Team
Global pharmaceutical company Lupin has secured approval from the European Medicines Agency (EMA) to expand the marketing authorization for NaMuscla (mexiletine), extending its indication to pediatric patients with non-dystrophic myotonic disorders (NDM). The regulatory update also introduces two new capsule strengths, 62 mg and 83 mg, alongside the existing 167 mg formulation, allowing age- and weight-appropriate dosing.
Supported by the agreed Pediatric Investigation Plan (PIP), the revised indication covers symptomatic treatment of myotonia in children aged 6 to 11 years weighing at least 20 kg, adolescents aged 12 to 17 years, and adults aged 18 years and older with non-dystrophic myotonic disorders. The approval expands access to the only licensed antimyotonic therapy for this rare neuromuscular condition in Europe.
NaMuscla Targets the Underlying Muscle Hyperexcitability
NaMuscla contains mexiletine, a voltage-gated sodium channel blocker that reduces skeletal muscle hyperexcitability responsible for myotonia. Its mechanism is effective regardless of the underlying ion channel defect, helping improve muscle relaxation and reducing symptoms such as stiffness, muscle cramps, difficulty releasing a grip, impaired mobility, and swallowing problems.
Non-dystrophic myotonic disorders are rare inherited neuromuscular diseases with an estimated prevalence of approximately 1 in 100,000 people. The disorders result from mutations affecting sodium or chloride ion channels in skeletal muscle membranes, leading to persistent muscle stiffness after voluntary contraction. Symptoms usually begin during childhood, progress over time, and can substantially impair daily activities and quality of life.
Clinical Evidence Supported Pediatric Label Expansion
The expanded indication is supported by the EMA-approved Pediatric Investigation Plan together with clinical evidence demonstrating the efficacy and safety of mexiletine in symptomatic myotonia.
Randomized controlled studies evaluating NaMuscla at daily doses ranging from 167 mg to 500 mg showed significant reductions in myotonia compared with placebo. Treatment also improved patient-reported quality of life and functional outcomes by reducing skeletal muscle hyperexcitability. The most commonly reported adverse event was gastrointestinal discomfort, while the overall safety profile remained favorable and consistent with previous experience.
The newly approved 62 mg and 83 mg capsule strengths support individualized dosing for younger patients and broaden treatment options for pediatric care.
Expanded Pediatric Access Addresses an Important Unmet Need
Commenting on the approval, Claus Jepsen, President of Global Specialty at Lupin, said the expanded pediatric indication represents meaningful progress for children and families living with non-dystrophic myotonic disorders, where therapeutic options remain limited. He added that the company remains focused on improving access to treatments across every stage of care.
Lupin plans to introduce the new dosage strengths and expanded pediatric indication across European markets as national implementation, reimbursement, and market access procedures are completed. The latest EMA decision strengthens the availability of targeted treatment for patients with a lifelong rare neuromuscular disease that has historically had few approved therapeutic options.
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About the Writer
Disha Sanjay Jadhao (LinkedIn) is a pharmacy graduate and healthcare writer with a strong interest in clinical documentation and simplifying healthcare information for better reader understanding. She is enthusiastic, adaptable, and eager to take on new challenges while contributing to clear, accurate, and engaging medical and pharmaceutical content.
