A new clinical trial shows promising results for gene therapy in treating cystic fibrosis patients. The results were recently published in the journal The Lancet Respiratory Medicine in a study entitled “Repeated nebulisation of non-viral CFTR gene therapy in patients with cystic fibrosis: a randomised, double-blind, placebo-controlled, phase 2b trial.”
The therapy replaces the mutated gene that causes Cystic fibrosis, Cftr (short for cystic fibrosis transmembrane conductance regulator) and was tested in a trial conducted by the UK Cystic Fibrosis Gene Therapy Consortium, a team of both scientists and clinicians from Imperial College London, the University of Oxford and University of Edinburgh, Royal Brompton & Harefield NHS Foundation Trust and NHS Lothian. In 2001 these organizations, supported by the Cystic Fibrosis Trust, set out to develop a gene therapy for cystic fibrosis.
The randomized, double-blind, placebo-controlled trial (phase 2b) enrolled cystic fibrosis patients who were at least 12 years old. In total, 140 patients were randomly assigned to receive either a placebo (n=62) or Cftr gene therapy (n=78). The treatment was administered every month for a whole year.
The researchers observed a significant, albeit at this stage still modest, benefit in lung function of cystic fibrosis patients treated with the therapy when compared to those in the placebo control group. This is the first trial showing how delivering repeated doses of gene therapy can improve patients’ lung function. They highlight, however, that further studies are required to optimize gene therapy efficacy and consistency of responses to be suitable for clinical care. These results prompt new trials and new and more efficient gene transfer vectors for treating cystic fibrosis and other diseases, which are caused by malfunctioning genes.
Professor Eric Alton, Consortium from Imperial College London coordinator, and study first author commented, “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. 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. We are looking to undertake follow-up studies assessing higher, more frequent doses as well as combinations with other treatments. The program came about through the generosity of the CF community via the CF Trust, whilst the trial exemplifies how effectively the MRC and NIHR, working in partnership, are able to move laboratory science into patient benefit. Publication of this trial is a landmark for CF patients and we are particularly grateful to the many patients across the UK who gave their time and effort to participate and make this collaborative venture a success.”
George Freeman, Minister for Life Sciences noted, “Cystic Fibrosis can have a devastating effect on patients and families and this is an excellent development for people living with the condition. The government is absolutely committed to supporting new medical treatments and invests £1bn a year in health research. It is vital we are at the forefront of turning scientific discoveries into tangible benefits and affordable treatments for NHS patients.”
A second therapy with a different vehicle for gene delivery is currently under development and will initiate the first clinical trial in 2016.
Ed Owen, Chief Executive of the Cystic Fibrosis Trust, added, “We are committed to improving and transforming the lives of people with cystic fibrosis, and the results of this pioneering clinical trial are a promising development. Further clinical research is now needed before we can say that it is a viable clinical therapy but it is encouraging that a proof of concept has been established. The Gene Therapy Consortium (GTC) has been supported by the cystic fibrosis community for many years and the Cystic Fibrosis Trust is proud to have funded the initial programmes that led to this trial. We have also committed a further £500,000 over the next two years to support the infrastructure of the consortium and to allow further development of its longer-term work to develop a viral vector gene therapy. This is an extraordinary time for therapeutic development in cystic fibrosis and the need is urgent to stop so many young lives being cut short because of this cruel condition. We will therefore continue to invest in innovative genetic research and to work with academic and industry partners to develop advancements which will make further progress towards our goal of a life unlimited by cystic fibrosis.”