[Aceneuraminic acid for distal myopathy]

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• GNE myopathy is a rare, inherited neuromuscular disorder characterized by progressive muscle weakness.
• Currently, there is no effective treatment for GNE myopathy, impacting patients' quality of life.
• The disease is caused by mutations in the GNE gene, affecting sialic acid biosynthesis.

Purpose of the Study:

• To evaluate the efficacy and safety of sialic acid therapy for GNE myopathy.
• To develop the first therapeutic drug for this ultra-orphan disease.
• To confirm the reproducibility of treatment effects in a Japanese patient population.

Main Methods:

• Clinical trials, including Phase I, II, and III studies, were conducted with aceneuraminic acid.
• Studies involved assessing muscle strength recovery and safety profiles in patients with GNE myopathy.
• A Phase II/III study in Japan utilized the same protocol as overseas Phase III trials.

Main Results:

• A Phase II trial demonstrated recovery of upper limb muscle strength with acenoiraminic acid sustained-release tablets.
• A subsequent Phase II/III study in Japan confirmed the efficacy and safety of the treatment.
• Despite initial setbacks in overseas Phase III trials, a Japanese confirmation study validated the drug's effects.

Conclusions:

• Aceneuraminic acid has been approved in Japan for the treatment of GNE myopathy, marking a significant advancement.
• This marks a successful development of a therapeutic drug for an ultra-orphan disease, offering hope for early patient intervention.
• The approval provides the first effective treatment option for patients diagnosed with GNE myopathy.