Researchers have launched a clinical trial at the NIH Clinical Center to evaluate the drug candidate DEX-M74 as a treatment for a rare degenerative muscle disease, hereditary inclusion body myopathy (HIBM).  DEX-M74, based on an NIH technology, is being developed through a collaboration between the NCATS Therapeutics for Rare and Neglected Diseases (TRND) program, the laboratories of NHGRI investigators Marjan Huizing, Ph.D. and William A. Gahl, M.D., Ph.D., and New Zealand Pharmaceuticals Limited (NZP), which is manufacturing DEX-M74 for the clinical trial and has obtained a license from the NIH to develop DEX-M74 as a treatment for HIBM.

HIBM, also known as GNE myopathy, has no available therapy. Disease symptoms emerge in adulthood and slowly lead to progressive muscle weakness. Most patients develop symptoms in their early 20s and eventually require a wheelchair as their arm, hand and leg muscles weaken.  Mutations in the GNE gene cause HIBM by reducing low sialic acid levels in muscle proteins, which is believed to contribute to the symptoms of muscle weakness.

The treatment under evaluation is based on a technology developed by a team of scientists led by Marjan Huizing, Ph.D., an associate investigator in NHGRI’s Medical Genetics Branch.  They hypothesized that the compound ManNAc (now called DEX-M74), a sugar that the body converts into sialic acid, might increase sialic acid levels in affected individuals.  They demonstrated that administration of ManNAc was effective in controlling sialic acid levels in mice with a specific GNE mutation, and published their findings in the June 2007 issue of the Journal of Clinical Investigation.

Read the NCATS news release.