A recent clinical trial has resulted in the green light for a new treatment aimed at patients suffering from a rare muscle-weakening disorder known as GNE myopathy.
To assist a group of patients affected by this uncommon condition, where muscle strength diminishes over time to the point of losing the ability to walk, a group of researchers in Japan has successfully concluded a clinical study that verifies the long-term safety of a new therapeutic drug.
The condition called distal myopathy with rimmed vacuoles, or GNE myopathy, is exceedingly rare and leads to muscle wasting and deterioration in the distal parts of the body, such as the fingers and ankles. Symptoms usually emerge during the teenage years or early thirties and result in significant loss of motor skills. This gradual decline in muscle strength severely impacts daily living, especially since there are no approved treatments available.
“Though there is a strong demand for a solution from patients, creating a treatment that slows the progression of this disease has been challenging due to its rare nature,” states Masashi Aoki, a professor from Tohoku University. “For instance, there are only about 400 individuals with GNE myopathy across Japan.” Given the small patient population, this treatment is classified as an “ultra orphan drug,” making it financially unattractive for pharmaceutical companies to invest in developing therapies for such a limited group. Consequently, these individuals often find themselves without any treatment options.
Despite these challenges, a dedicated group of researchers has worked to create a treatment. Patients with GNE myopathy have a reduced ability to produce an enzyme essential for generating sialic acid, so they were administered a drug that includes aceneuramic acid, a form of sialic acid, to address this deficiency.
The researchers carried out phase I and phase II/III trials initiated by investigators, plus an efficacy confirmation study funded by Nobelpharma Co., Ltd. These studies successfully showed the effectiveness of the ultra-orphan drug, “Aceneuramic Acid (Acenobel®) Extended Release Tablets 500mg,” designed for GNE myopathy.
In this latest research, 19 patients with GNE myopathy underwent a 72-week treatment regime without experiencing notable adverse effects. These individuals previously took part in a 48-week double-blind study to compare the drug against a placebo, and the treatment duration was extended to 72 weeks for this next phase. The ongoing research confirmed both the safety and effectiveness of this treatment, resulting in Nobelpharma Co., Ltd. receiving official manufacturing and marketing clearance from Japan’s Ministry of Health, Labour and Welfare in March 2024. This approval brings promising news for patients, as they now have access to a safe and effective treatment option.
The research team intends to keep evaluating the treatment’s efficacy over even longer periods.
The findings from this extension study were made available online on June 5, 2024, in the Journal of Neurology, Neurosurgery, and Psychiatry.
