06 July 2015
ByAppeared in BioNews 809
A new gene therapy technique for treating cystic fibrosis has shown potential in a new study.
The results from the year-long trial, published in the Lancet Respiratory Medicine, showed a slight improvement in a sample of 136 patients with cystic fibrosis, aged 12 years and over.
'Patients who received the gene therapy showed a significant, if modest, benefit in tests of lung function compared with the placebo group; there were no safety concerns,' said Professor Eric Alton from Imperial College London, who led the trial. 'Whilst the effect was inconsistent, with some patients responding better than others, the results are encouraging, laying the groundwork for further trials which we hope could improve the effect.'
Cystic fibrosis affects around 10,000 people nationally and over 90,000 worldwide. It is one of the commonest inherited diseases, caused by mutations in a single gene, the CFTR. The lungs of patients with cystic fibrosis are particularly affected as they are susceptible to recurrent infections, becoming filled with thick and sticky mucus.
In the trial, the DNA sequence of the replacement gene was encased in fatty bubbles for easy absorption from the cells lining the lungs, were delivered to the patients using a device similar to an asthma inhaler.
The participants, who breathed in the replacement gene every month for a year, had, on average, a 3.7 percent improvement in their lung function compared with the placebo group. The lung function of patients with cystic fibrosis usually worsens by 2–3 percent a year, and people with the disease have currently an expected life span of 41 years.
Professor Alton said that a follow-up study would likely increase the dosage, and he said that he believes it is feasible to effectively stabilise lung function by the end of this decade.
Professor Stuart Elborn of Queen's University in Belfast, who was not involved in the study, said the results were 'encouraging' but was cautious about such predictions.
'If I was on the board of a pharmaceutical company, I would require further studies to determine the best dose and whether the current treatment could be combined with other drugs to increase the effect,' he said. 'It is too soon to proceed with larger phase-three trials costing many millions.'
The trial was launched in 2012 and carried out by the UK Cystic Fibrosis Gene Therapy Consortium that brings together scientists and clinicians form Imperial College London, universities of Oxford and Edinburgh, Royal Brompton and Harefield NHS Foundation Trust and NHS Lothian.
The consortium is also developing a second approach that will also use a virus system to deliver the DNA into the lung. The first clinical trial of this kind will begin in 2016.