For the first time, gene therapy for the incurable lung disease cystic fibrosis (CF) has shown a “significant if modest benefit” in improving lung function, according to the results of a study
published on 3 July 2015 in The Lancet Respiratory Medicine.
Researchers involved in the trial have described publication of the results as a “landmark” for people with the disease, which is caused by mutations in a single gene.
“The data reported here provide the first proof of concept that repeated administration of non-viral cystic fibrosis transmembrane conductance regulator (CFTR) gene therapy can safely change clinically relevant parameters, providing another step along the path of translational cystic fibrosis gene therapy,” they say.
The two-year phase II randomised trial involved 136 patients aged over 12 years from the UK who had cystic fibrosis.
The patients were given either 5ml of nebulised pGM169/GL67A gene therapy or a placebo each month for a year. Their lung function was measured at the beginning of the trial and again at the end, according to the volume of air forcibly exhaled in one second (FEV1).
At the end of the 12 months, lung function in those patients given the gene therapy had stabilised and was found to be 3.7% greater than the lung function of patients in the placebo group, who experienced a deterioration over the same period.
But the results were inconsistent among patients in the gene therapy group. Patients with the worst lung function at the start of the study recorded an improved lung function of 6.4%.
The researchers say their findings should encourage the rapid introduction of more potent gene transfer vectors into early phase trials.
“Further improvements in efficacy and consistency of response to the current formulation are needed before gene therapy is suitable for clinical care,” they say.
The findings are encouraging, but need to be put into perspective. “We noted a stabilisation of FEV1 in the pGM169/GL67A group rather than an improvement,” the researchers write. “This stabilisation took place over a one-year period and further work will be needed to see if this effect is maintained.”
The results of the study were welcomed by patient group the Cystic Fibrosis Trust. The trust is a member of the UK Cystic Fibrosis Gene Therapy Consortium, which coordinated the research.
“The results of this pioneering clinical trial are a promising development,” says the trust’s chief executive Ed Owen. “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.”
 Alton EWFW, Armstrong DK, Ashby D et al. Repeated nebulisation of non-viral CFTR gene therapy in patients with cystic fibrosis: a randomised, double-blind, placebo-controlled, phase 2b trial. The Lancet Respiratory Medicine 2015. doi:http://dx.doi.org/10.1016/S2213-2600(15)00245-3.