ManNAc is an abbreviation for N-acetyl-D-mannosamine. ManNAc is an uncharged sugar and an intermediate molecule in the production of sialic acid within cells (See Figure). Patients with GNE myopathy have decreased GNE enzyme activity, and do not produce enough ManNAc or sialic acid. This deficiency results in a decreased attachment of sialic acid groups to skeletal muscle cells, which is thought to be the cause of the muscle wasting in GNE myopathy.
Studies have shown that supplementation of ManNAc to cell cultures or to mice with a dysfunctional GNE protein (as in GNE myopathy) bypasses the need for GNE function and enables the production of sialic acid.
Studies in mouse models of GNE myopathy have shown efficacy of oral ManNAc in mice with GNE Myopathy.
ManNAc is currently under investigation by NIH researchers in collaboration with Escala Therapeutics in an Open-Label Phase 2 study.
The FDA has provided an orphan designation for ManNAc to treat GNE Myopathy.
A Natural History Study of Patients with GNE Myopathy (ongoing, recruiting)
An Open-Label Phase 2 Study ManNAc in Subjects with GNE Myopathy (ongoing, not recruiting)
Multicenter Trial of ManNAc for GNE Myopathy
Coming in 2018
Last Updated: Januuary 2, 2018