NICE Recommends Namuscla for NHS Coverage to Treat Non-Dystrophic Myotonia in Adults

Compiled and Translated by 丨 Fan Dongdong

Recently, the UK's National Institute for Health and Care Excellence (NICE) published a draft guideline recommending the inclusion of Lupin's Namuscla in the UK's National Health Service (NHS) for the treatment of adult patients with non-dystrophic myotonia (NDM) to improve myotonia symptoms.

Following this favorable development, it is estimated that approximately 250 patients in the UK will be eligible for treatment with Namuscla. NICE had been widely anticipated to approve Namuscla, as it is the only product holding a UK marketing authorization for the treatment of this condition. Patients currently have access to the therapy through an agreement between NHS England, NHS Improvement, and the manufacturer. Prior to the approval of Namuscla, standard clinical treatment options typically included imported mexiletine (which is not licensed in the UK) and other sodium channel blockers.

Mexiletine is a sodium channel antagonist that inhibits the flow of sodium ions, delays the propagation of nerve impulses, and suppresses skeletal muscle hyperexcitability, thereby alleviating the symptoms of myotonia in patients. Clinical trial evidence indicates that Namuscla is more effective than placebo in reducing myotonia symptoms; however, the trial did not compare Namuscla with other sodium channel blockers available within the NHS healthcare system (such as lamotrigine, carbamazepine, acetazolamide, flecainide, and phenytoin).

Furthermore, the dose of Namuscla used in the clinical trials was higher than that typically used in the NHS, and the magnitude of clinical benefit was uncertain. Despite the aforementioned limitations in the trial results, Namuscla was still considered a cost-effective use of NHS resources and recommended for routine treatment.

Non-dystrophic myotonia is a rare genetic disorder that affects the muscles. The most common symptom is myotonia, a condition characterized by delayed muscle relaxation, which can lead to muscle stiffness and locking, pain, sleep disturbances, and falls. Myotonia also significantly impairs patients' quality of life and may cause difficulties in performing daily tasks, such as lifting heavy objects, climbing stairs, or bathing. For years, sodium channel blockers, including mexiletine, have been used clinically to treat non-dystrophic myotonia. Because it is a rare disease, Namuscla was granted "orphan drug" designation in 2014.

The drug received marketing authorization in the European Union on December 18, 2018, under the trade name NaMuscla, for the treatment of symptomatic myotonia in adult patients with non-dystrophic myotonia (NDM), and was granted orphan drug designation by the European Medicines Agency (EMA). On December 8, 2020, Lupin announced that the Scottish Medicines Consortium (SMC) had approved NaMuscla (mexiletine) for the treatment of symptomatic myotonia in adult patients with non-dystrophic myotonia (NDM).

Source: NICE recommends Namuscla for NHS to treat genetic disorder