New developments in exon skipping and splice modulation therapies for neuromuscular diseases

Abstract

Introduction: Antisense oligonucleotide (AON) therapy is a form of treatment for genetic or infectious diseases using small, synthetic DNA-like molecules called AONs. Recent advances in the development of AONs that show improved stability and increased sequence specificity have led to clinical trials for several neuromuscular diseases. Impressive preclinical and clinical data are published regarding the usage of AONs in exon-skipping and splice modulation strategies to increase dystrophin production in Duchenne muscular dystrophy (DMD) and survival of motor neuron (SMN) production in spinal muscular atrophy (SMA).

Areas covered: In this review, we focus on the current progress and challenges of exon-skipping and splice modulation therapies. In addition, we discuss the recent failure of the Phase III clinical trials of exon 51 skipping (drisapersen) for DMD.

Expert opinion: The main approach of AON therapy in DMD and SMA is to rescue (‘knock up’ or increase) target proteins through exon skipping or exon inclusion; conversely, most conventional antisense drugs are designed to knock down (inhibit) the target. Encouraging preclinical data using this ‘knock up’ approach are also reported to rescue dysferlinopathies, including limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, distal myopathy with anterior tibial onset and Fukuyama congenital muscular dystrophy.

Keywords::

• antisense therapy
• Duchenne muscular dystrophy
• dysferlinopathy
• exon skipping
• Fukuyama congenital muscular dystrophy
• limb-girdle muscular dystrophy 2B
• Miyoshi myopathy
• spinal muscular atrophy
• splice modulation

Declaration of interest

This work was supported by the University of Alberta Faculty of Medicine and Dentistry, Parent Project Muscular Dystrophy (USA), The Friends of Garrett Cumming Research Funds, HM Toupin Neurological Science Research Funds, Muscular Dystrophy Canada, Canada Foundation for Innovation, Alberta Enterprise and Advanced Education, the Women and Children's Health Research Institute and Canadian Institute of Health Research. T Yokota has been and is currently the principal investigator of federal grants aiding the development of morpholino chemistry for exon skipping. The remaining authors have no competing interests to declare.

Notes

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