Duchenne Muscular Dystrophy (DMD) is a severely debilitating childhood neuromuscular disease that affects 1 in 3,500 live male births. This rare disease is caused by mutations in the dystrophin gene, resulting in the absence or defect of the dystrophin protein.
Patients suffer from progressive loss of muscle strength due to the absence or defect of the dystrophin protein, often making them wheelchair bound before the age of 12. Respiratory and cardiac muscle can also be affected by the disease and most patients die in early adulthood due to respiratory and cardiac failure.
The dystrophin gene is the largest gene in the body, consisting of 79 exons. In DMD, when certain exons are mutated/deleted, the RNA cannot read past the fault. This prevents the rest of the exons being read, resulting in a non-functional dystrophin protein and the severe symptoms of DMD.
RNA-based therapeutics, specifically antisense oligonucleotides inducing exon skipping, are currently in development for DMD. This technology uses small pieces of DNA called antisense oligonucleotides to skip a defective exon and thereby correct the reading frame, enabling the production of a normal dystrophin protein. Up to 13% of boys with DMD have dystrophin gene mutation/deletions amenable to an exon 51 skip.
“The commencement of this Phase III study is an important milestone,” said Dr Philippe Monteyne, Head of Development and Chief Medical Officer for GSK Rare Diseases. “Currently, there is no approved treatment to alter the course of DMD – a disease that puts boys in wheelchairs and often leads to death in early adulthood.”
“We are very pleased with this achievement. It is another step forward in our joint fight against Duchenne,” said Dr Giles Campion, Chief Medical Officer of Prosensa. “If the results of this study are positive, we hope it will lead to an approved treatment option for the thousands of young people worldwide living with this devastating disease.”
Prosensa is an innovative Dutch biopharmaceutical company focused on the discovery, development and commercialization of RNA modulating therapeutics correcting gene expression in diseases with large unmet medical needs, in particular neuromuscular disorders. Prosensa’s focus is on developing a treatment for DMD.