Aceneuramic Acid

Aceneuramic acid (sialic acid) extended release is an investigational oral formulation of sialic acid intended for the treatment of GNE Myopathy, also known as Hereditary Inclusion Body Myopathy (HIBM). 

GNE Myopathy is a rare, severe, progressive, genetic neuromuscular disease caused by a defect in the biosynthetic pathway for sialic acid, with onset usually after age 20. The body's failure to produce enough sialic acid causes muscles to slowly waste away and can lead to very severe disability, with patients typically becoming wheelchair bound within ten to 20 years and ultimately having to rely on others for daily care due to the loss of upper extremity and other muscle function.

There are currently no approved therapies for GNE Myopathy. Supportive care is aimed at compensating for muscle weakness and enhancing remaining muscle function to improve quality of life for patients. These treatment options may include physical and occupational therapy to attempt to improve muscle strength and, when necessary, the use of various devices including braces.

Ultragenyx has licensed rights to aceneuramic acid extended release and its potential use in treating  GNE Myopathy from Nobelpharma, AAI Pharma, and the HIBM Research Group.

Mechanism of Action

Aceneuramic acid extended release is intended to bypass the genetic block in the sialic acid pathway and provide continuous exposure over 24 hours. It is expected that the muscles will pick up increased amounts of sialic acid from the serum, incorporate it into proteins and fats, and potentially improve muscle strength and function over time

News & Other Information

Press Releases

Data Presentations/Publications

Clinical Trials

Aceneuramic Acid


Phase 3


GNE Myopathy (GNEM)


2,000 developed world patients

disease mechanism

Deficiency of sialic acid

Key Symptoms

Progressive muscle wasting
Loss of ability to walk
Loss of upper limb function

treatment mechanism

Replace deficient sialic acid