Patients who received therapy showed a significant but modest benefit in lung function compared with those receiving a placebo. The trial is the first to show that repeated doses of gene therapy can have a meaningful effect on the disease, and change the lung function of patients. However, the team say more research is needed to improve the effectiveness before the therapy will be suitable for clinical use.

Cystic fibrosis (CF) is the commonest lethal inherited disease in the UK, affecting around 10,000 people nationally and over 90,000 worldwide. Patients' lungs become filled with thick sticky mucus and they are vulnerable to recurrent chest infections, which eventually destroy the lungs.

The trial, conducted in London and Edinburgh, compared the effects of inhaled gene therapy and a placebo on patients with CF aged 12 and over. Lung function was assessed using a common method of measuring the volume of air a patient can forcibly exhale in one second. Over the course of a year, patients were given 12 treatments at monthly intervals. The results, published in The Lancet Respiratory Medicine, showed that at the end of the trial lung function was 3.7% better in patients who received the 'active' treatment. Participants with the worst lung function at the start of the study experienced a much greater 6.4% gain compared with those in the placebo group.

Eoin Treacy's view

Gene therapy has been a long time coming and still has a long way to go but the promising results from human trials is a major step forward in the commercialisation of decades of research. 

The iShares Biotechnolgy ETF continues to hold a progression of higher reaction lows and a sustained move below the 200-day MA would be required to begin to question medium-term upside potential. 

Among the more impressive bounces include Immunogen which surged higher in early June to break a long-term progression of lower rally highs and rallied today to break out of a short-term range.