Mumbai, Zug, July 1, 2026 – Global pharma major Lupin Limited (Lupin) today announced that the European Medicines Agency (EMA) has approved a change to the terms of marketing authorization for NaMuscla, supported by the Pediatric Investigation Plan (PIP). The approval includes two new dosage strengths, 62 mg and 83 mg capsules, in addition to the existing 167 mg, and the revised indications that cover symptomatic treatment of myotonia in children (6–11 years, weighing at least 20 kg), adolescents (12–17 years), and adults (≥18 years) with non-dystrophic myotonic disorders.
Claus Jepsen, President, Global Specialty, Lupin, said, "This EMA approval for Pediatric Indication of NaMuscla represents a significant step forward for patients and families living with non-dystrophic myotonic disorders—especially children, where options are scarce. At Lupin, we remain committed to broadening access to therapies that improve outcomes across every stage of care."
Lupin is now working towards making new dosage strengths and expanded pediatric indication available across Europe, subject to local implementation timelines and national reimbursement and access processes.
Notes for Editors
About Myotonic Disorders and Non-Dystrophic Myotonias (NDM)
Myotonic disorders are a group of heterogeneous, inherited, neuromuscular disorders characterized by a shared symptom called myotonia. Myotonia can be described as an inability to relax a contraction of skeletal muscle which originates from a voluntary muscular contraction such as shaking someone's hand and blinking, or everyday activities such as walking across a street and climbing stairs.
Non-dystrophic myotonias (NDM) are a sub-set of rare (prevalence of 1:100,000), inherited, myotonic disorders which are caused by mutations within ion channels in the sarcolemma membrane of skeletal muscles. Non-dystrophic myotonias exhibit both sodium and chloride channelopathies which result in altered membrane excitability. For patients with NDM, myotonia is the most prominent symptom and demonstrates different phenotypes in subgroups of NDM disorders, and can affect different parts of the body, such as legs, arms, or facial muscles, more severely.
Myotonia in NDM patients has an onset in childhood and persists across their lifetime. Patients perceive that myotonia increases in severity over time, impacting daily life. Myotonia is described by patients in a variety of ways (stiffness, cramps, pain, difficulty releasing a fist, or difficulty swallowing or eating) which can contribute to substantial delays in diagnosis and treatment, leading to decreased patient quality-of-life and often significant disability.
About NaMuscla (mexiletine)
NaMuscla is the only antimyotonic agent licensed to treat symptomatic myotonia in children aged 6 to 11 years weighing at least 20 kg, adolescents aged 12 to 17 years and adult patients more than 18 years with non-dystrophic myotonic disorders. In randomized controlled trials, NaMuscla (167 to 500 mg/day) has been shown to significantly reduce myotonia compared to placebo, reducing skeletal muscle hyperexcitability through its use-dependent, voltage-gated, sodium channel blocking actions which are independent of the cause of channel function. This resulted in an improvement in patient quality-of-life and other functional outcomes, with gastro-intestinal discomfort reported as the most common adverse event, demonstrating NaMuscla to be safe and well tolerated.
References
- Namuscla | European Medicines Agency (EMA)
- Matthews E, et al. Brain 2010;133:9–22
- Diaz-Manera J, et al. EMJ. 2021;6[2]:37-46
- Trivedi JR, et al. Brain 2013; 136:2189-200
- Emery AEH, Neuromuscular Discord 1991;1:19-29
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- Matthews E, et al. Pract Neurol 2021;0:1–10
- Stunnenberg, et al. Muscle Nerve 2020;62(4):430-444
- NaMuscla®. Summary of Product Characteristics. Namuscla, INN-mexiletine
About Lupin
Lupin Limited is a global pharmaceutical leader headquartered in Mumbai, India, with products distributed in over 100 markets. Lupin specializes in pharmaceutical products, including branded and generic formulations, complex generics, biotechnology products, and active pharmaceutical ingredients. Trusted by healthcare professionals and consumers globally, the company enjoys a strong position in India and the U.S. across multiple therapy areas, including respiratory, cardiovascular, anti-diabetic, anti-infective, gastrointestinal, central nervous system, and women's health. Lupin has 15 state-of-the-art manufacturing sites and 7 research centers globally, along with a dedicated workforce of over 24,000 professionals. Lupin is committed to improving patient health outcomes through its subsidiaries - Lupin Diagnostics, Lupin Digital Health, and Lupin Manufacturing Solutions.
To know more, visit www.lupin.com or follow us on LinkedIn at https://www.linkedin.com/company/lupin
For further information or queries, please contact
Rajalakshmi Azariah
Vice President & Global Head – Corporate Communications, Lupin
rajalakshmiazariah@lupin.com
