New drug hope for cystic fibrosis patients

Sep 10 2008

A science conference in the UK has heard some good news which offers hope to cystic fibrosis (CF) patients worldwide.

At the BA Festival of Science in Liverpool this week, Dr. David Sheppard from the University of Bristol said a new drug therapy may represent a tremendous step forward in the treatment of cystic fibrosis.

According to Dr. Sheppard the early results with the drug VX-770 suggest that drug therapies which target defects at the root of the disease have the potential to greatly improve the quality of life of CF patients.

There is currently no cure for CF, which is a hereditary disease caused by a common single, defective gene disorder which affects about 70,000 people worldwide.

CF causes ducts and tubes in the body to become blocked by a thick, sticky mucus which affects the lungs, pancreas, the intestines, the liver and the reproductive organs.

Most individuals with cystic fibrosis die young, many in their 20s and 30s from lung failure but with the introduction of many new treatments, the life expectancy of a person with CF is increasing to ages as high as 40 or 50.

The treatment as a rule targets airway infection along with the encouragement of good nutrition and an active lifestyle.

The treatment for CF continues throughout a patient's life and is aimed at maximizing organ function, and therefore quality of life, but at best, current treatments serve only to delay the decline in organ function.

Treatment is tailored to the individual, because of the wide variation in disease symptoms and targets the lungs, gastrointestinal tract, the reproductive organs and psychological support; therapies such as transplantation and gene therapy aim to cure some of the effects of cystic fibrosis.

The most consistent aspect of therapy in cystic fibrosis is limiting and treating the lung damage caused by the thick mucus and infections, with the goal of maintaining quality of life.

Intravenous, inhaled, and oral antibiotics are used to treat chronic and acute infections and mechanical devices and inhalation medications are used to alter and clear the thickened mucus.

One of the most recognisable symptoms of CF is 'salty sweat', caused by the failure of the sweat ducts to reabsorb salt and existing treatments only alleviate symptoms, for example, physiotherapy to clear the air passages, antibiotics for lung infections and enzymes to aid the digestion of food.

The defective gene disables or destroys a protein known as CFTR and to date around 1,500 genetic defects have been found in this protein which cause harm in two ways - some stop the protein from travelling to its correct destination in cells, whereas others prevent the protein from working properly.

Dr Sheppard's research group, supported by the Cystic Fibrosis Trust, has investigated how new drugs restore function to defective CFTR proteins and EuroCareCF, of which Dr Sheppard is the coordinator, works to promote CF therapy development in Europe.

The new drug therapy (VX-770) was developed by Vertex Pharmaceuticals and funded by the Cystic Fibrosis Foundation; it will tackle the 'functional' defect and has been tested on CF patients in the U.S. who carry a genetic defect known as G551D.

European trials are expected in the future but so far the early results are very encouraging and patients who received 150mg twice a day saw the concentration of salt in their sweat decrease by almost 50 per cent and lung function improve by 10 per cent.

To date the Foundation has invested $79 million in the project and Dr Sheppard's research group and other academic groups and companies are also working to develop new drugs that tackle defects at the root of CF.

Cystic fibrosis one of the most common life-shortening, childhood-onset, inherited diseases.