Ivacaftor improves the function of CFTR, the protein that causes cystic fibrosis, and leads to improved lung function, healthier weight and fewer flare-ups of worsening lung health. The drug is effective for around 5% of people with CF in the UK with specific CF mutations, and it has been available on the NHS since 2013.
In a recently-published study, Liverpool-based researchers used UK CF Registry data to look at the number of lung infections experienced by people taking ivacaftor in comparison to those who weren’t on the drug. They found that people who were taking ivacaftor had fewer lung infections than those who weren’t.
The clearest data they analysed came from looking at Pseudomonas aeruginosa infection. Using data from the years before and after ivacaftor became available, the researchers were able to show that after three years the people taking the drug were 33% less likely to have Pseudomonas in their sputum than the people not taking it.
It is not completely clear how ivacaftor might be reducing the infection levels in people with CF and more lab-based research is needed to work this out.
A study using Registry data
These results weren’t gathered through a clinical trial, but were instead obtained from statistical analysis of routinely-collected data from annual reviews.
Every year, for the 99% of people with CF who have consented to their data being submitted to the UK CF Registry, data from their annual review is added to their Registry record. This includes things like what drugs they’re on and which, if any, lung infections they’ve developed. Using this data, the researchers performed a statistical analysis on the recorded infection levels for people on ivacaftor compared to people who weren’t on the drug.
Anonymous data from 276 people who were taking ivacaftor in 2013 was tracked for three years. Their data was compared to data from 5,296 people who weren’t on ivacaftor during the same time period. While other registry studies around the world have looked at the effects of ivacaftor on infection levels before, this study tracked the largest number of people for the longest period of time.
Dr Freddy Frost, a cystic fibrosis researcher at Liverpool Heart and Chest Hospital who led the study said “This study is a good example of how UK CF Registry data can be used to evaluate long-term outcomes associated with new CF drugs. Clinical trials are often relatively short in length and restricted to small numbers of people with CF, so while clinical trials are important for telling us if drugs work well in the short term, they can’t always capture all their long-term potential benefits. If we think that a drug already in use has added benefits we can test this out by using statistical analysis of Registry data. The results of these registry studies can help us to provide better information to people with CF about what they can expect when they receive a drug like ivacaftor.”
Changes to future care
These results have exciting implications for the future of CF care. Dr Frost said: “People with CF notice improvement in lung function and quality life soon after they start taking ivacaftor, but they still have to live with a considerable treatment burden from all the other medications they take.
“At present, we simply don’t know whether it’s safe to stop some of those other treatments. The fact we have seen reduced infections in this UK CF Registry study suggests there may be some people who can safely discontinue medications targeted towards those infections. However, we need to perform further research before we can safely recommend this approach to patients.”
Advancing research and improving clinical care
Rebecca Cosgriff, Director of Data and Quality Improvement at the Trust, said: “One of the advantages of the UK CF Registry is that we can look for hints of emerging trends, either in treatments or complications. These changes can alert researchers, policy makers and CF centres to areas that need more focus.
“Last week we published the 2018 UK CF Registry Annual Data Report, showing trends in clinical care, and this study is an example of using this data to find out the best ways of treating and beating cystic fibrosis.”
The UK CF Registry Steering Committee approve around 35 requests from researchers to access anonymous data from the UK CF Registry every year. More information on how to apply to access the data is available on our website.