Posted on 28/07/2011
The Dystrophin protein forms a honeycomb structure which strengthens and protects the surface membrane of muscle fibres. Dystrophin is completely missing in the debilitating childhood illness Duchenne muscular dystrophy
Professor George Dickson, from the School of Biological Sciences at Royal Holloway, University of London and a team lead by scientists at the UCL Institute of Child Health (ICH), have made an important breakthrough in the development of a treatment for Duchenne Muscular Dystrophy (DMD).
The research, funded by the Medical Research Council (MRC) and AVI BioPharma, was published in The Lancet on 25th July 2011.
Together with the MDEX Consortium, the group showed that a gene-based drug treatment was effective in restoring the dystrophin protein that is missing in sufferers of DMD, in seven out of 19 trial participants.
DMD is a devastating and life-limiting condition that affects one in 3,500 male births in the general population, with around 100 cases diagnosed in the UK each year.
Three of the participants in the two highest dose cohorts showed dystrophin levels that exceeded 18 per cent of those found in normal muscle cells. There was significant statistical increase across the cohorts.
Thirteen per cent of boys with DMD could be treated with this gene specific, exon-skipping therapy, the largest group by a single antisense. Overall scientists say this approach could work for at least 70 per cent of DMD sufferers.
DMD causes progressive muscle weakness due to the breakdown and loss of muscle cells. Patients lack a single important protein in their muscle fibres called dystrophin. By the ages of eight to 12, boys become unable to walk and by their late teens or early twenties the condition can become severe enough to limit life expectancy.
In this clinical trial of 19 patients, study participants aged five to 15 at Great Ormond Street Hospital and the Royal Victoria Infirmary, Newcastle, were given weekly doses of the drug, AVI-4658. The drug had already been tested for safety and efficacy by the MDEX Consortium and AVI Biopharma in an earlier phase of the study (Kinali et al, Lancet Neurol 2009).
Professor Dickson said: “We are moving towards the era of personalised genetic medicine. My team at Royal Holloway was first to describe this new type of gene correction therapy back in the late ‘90s, and we have worked since then to develop the new drugs to the stage of clinical trials in patients.
"The Lancet publication describes another exciting and important milestone towards finding an effective treatment for Duchenne muscular dystrophy. More research is needed, but the results of the clinical trial are extremely encouraging.”