AbstractBackgroundHereditary inclusion body myopathy (HIBM) is an autosomal recessive adult onset myopathy. It is characterized by mutations of the GNE (UDP‐N‐acetylglucosamine 2‐epimerase/N‐acetylmannosamine kinase) gene. Afflicted patients have no therapeutic options. In preclinical testing, we have previously demonstrated the ability to correct GNE gene function and the safety of delivery of wild type GNE gene using a liposomal delivery vehicle.MethodsA single patient (subject #001) with severe HIBM treated by compassionate investigational new drug received four doses of GNE gene Lipoplex via intramuscular injection. GNE transgene expression, downstream induction of sialic acid, safety and muscle function were evaluated.ResultsSignificant durable improvement in locoregional skeletal muscle function was observed in the injected left extensor carpi radialis longus of #001 in correlation with GNE transgene upregulation and local induction of sialic acid. Other than transient low grade fever and pain at the injection site, no significant toxicity was observed.ConclusionsProof of principle for manufacturing of ‘clinical grade’ GNE gene Lipoplex, clinical safety and activity are demonstrated with GNE gene Lipoplex. Further assessment will involve intravenous administration and subsequent phase I trial involving additional but less severely afflicted HIBM patients. Copyright © 2010 John Wiley & Sons, Ltd.