22 January 2016
Children born with a specific mutation of cystic fibrosis (CF) could see improvements in their condition if they have access to the oral drug therapy, Ivacaftor, earlier in life, according to research carried out at Royal Brompton Hospital.
The clinical trial, which is the first to examine the safety and effectiveness of the drug in children aged between two and five years old, showed that after six months, several significant markers of the disease had improved. The findings, published in The Lancet Respiratory Medicine this week, suggest that these improvements at an early age could lead to increased lung and pancreatic function in older children.
Ivacaftor is suitable for around five per cent of cystic fibrosis patients who have a number of specific CF gene mutations. These patients have mutations that interfere with the process by which a channel in a cell membrane opens or closes, known as a ‘gating mutation’. Previous research has confirmed that the drug is safe and effective in children aged six and older, adolescents and adults.
CF is an inherited disease caused by a defective gene that slowly destroys the lungs and digestive system. The defective gene disrupts the activity of a protein called the CF transmembrance conductance regulator (CFTR), which regulates salt transport in the body’s cells. This causes thick, sticky mucus to build up in organs, especially the lungs and digestive system, and leads to recurring infections and irreversible lung damage. Around 10,000 people are living with cystic fibrosis in the UK and there is no cure.
In 80–90 per cent of cystic fibrosis patients, pancreatic function is irreversibly damaged from early life, which means that the pancreas no longer functions at a level needed to digest food. As a result, children with cystic fibrosis often have problems maintaining or gaining weight and need medication with every meal to help digestion.
The study, which was funded by the drug’s manufacturers Vertex, showed that taking Ivacaftor at one of two doses (50mg for children weighing less than 14 kg and 75mg for those over 14 kg) twice daily for six months improved sweat chloride levels (diagnostic of the disease), weight gain and pancreatic function.
Significant reductions in sweat chloride levels suggested an improvement in the body’s ability to restore the balance of salt in and out of cells. Meanwhile, the researchers believe that improved weight gain at this stage in life could protect against a future decline in nutritional levels and result in better lung function in later childhood.
The pancreatic function of over a quarter of the children who took part in the study improved to such an extent that it was no longer classed as insufficient, at least once during treatment. The researchers say this suggests “a window in early life where at least partial restoration of pancreatic function might be possible”. This is the first time this has been shown with any drug in CF patients.
More research is now needed to confirm the drug’s long-term effects and safety in young children; in particular, some young children seemed prone to abnormal liver function test values, which will need careful monitoring. Professor Jane Davies, consultant in paediatric respiratory medicine at Royal Brompton Hospital and professor in paediatric respirology and experimental medicine at the National Heart and Lung Institute at Imperial College London, led the study. She said:
“Although this was a small trial we are excited by the results, which highlight the potential that Ivacaftor has to improve the lives of children with cystic fibrosis. The treatment could make a real difference to future generations born with the condition and could lead the way to even greater progress in years to come.”