In order to treat an underserved population of patients with a rare condition whose muscles gradually become weaker until they can no longer walk, a team of researchers across Japan have completed a clinical study to confirm the safety of long-term administration of a therapeutic drug. Distal myopathy with rimmed vacuoles, or GNE myopathy, is a very rare disease in which muscle atrophy and degeneration occurs in the distal limbs (such as fingers and ankles). Symptoms typically begin from the teens to the early 30s.
It gradually leads to a profound loss of motor control. This can greatly affect one's quality of life as they slowly lose muscle strength, without any approved treatments available. Despite there being a demand from patients, developing a treatment to slow down symptom progression has been difficult due to the rarity of the disease.
For example, there are approximately 400 people with GNE myopathy in all of Japan." Masashi Aoki, Professor from Tohoku University A treatment for a population this size is considered an "ultra orphan drug" - because it is not profitable for pharmaceutical companies to develop treatment for such a small group. As a result, these patients are "orphaned" and left without any help.
Despite these hurdles, a team of researchers stepped in to develop a treatment. Patients with GNE myopathy have reduced functioning of an enzyme that produces sialic acid, so patients were given a drug containing aceneuramic acid (a type of sialic acid) to suppl.