Introduction and Objectives The CFTR potentiator, Ivacaftor, has recently been launched in England for use in adult cystic fibrosis patients with at least one copy of the G551D mutation. Formal clinical trials have demonstrated significant improvements in spirometry, weight and quality of life symptom scores in patients taking this new drug. We wish to report our experience of Ivacaftor in a standard clinic setting through longitudinal follow-up of our patients over a six month period.
Methods 11 patients were started on Ivacaftor between December 2012 and February 2013. Before starting Ivacaftor we measured spirometry (FEV1 and FVC), weight, liver function tests, quality of life symptom scores and the number of antibiotic courses for infective exacerbations in the preceding 3 months. Repeat measurements were taken at 3 months after starting Ivacaftor and compared to baseline. Liver function tests were monitored as per manufacturer’s advice, with the intention to stop Ivacaftor if there was a significant rise in liver function tests.
Results 10 patients remained on Ivacaftor at 3 months (one patient was lost to follow-up). Baseline spirometry in these patients demonstrated an average percentage predicted FEV1 of 58.2% (SD ± 19.8) and average percentage predicted FVC of 77.9% (SD ± 22.2). Spirometry improved in all patients at 3 months compared to baseline; average increase in predicted FEV1 12.2% (p = 0.010) and average increase in predicted FVC 15.8% (p = 0.006). All but one patient gained weight with an average weight increase of 2.1 kg (p = 0.013). The use of antibiotics to treat exacerbations significantly improved; only 1 patient required antibiotics in the 3 months after starting Ivacaftor. One patient, whilst taking concomitant anabolic steroids, had to stop Ivacaftor after a six-time rise in alanine transaminase. After stopping steroids, he subsequently restarted Ivacaftor without deterioration in liver function.
Conclusions At 3 months our patients demonstrated statistically significant improvements in spirometry and weight after starting Ivacaftor. Importantly, Ivacaftor has been well tolerated with reported improvements in symptom burden and reduced exacerbation rates; 3 patients have returned to work/changed jobs and one has starting full-time education. Further results from six month follow-up, including quality of life symptom scores, are awaited.