Dramatic clinical stabilisation following introduction of ivacaftor in an adult patient with cystic fibrosis (CF) and R117H/5T mutation

A 35-year-old man with CF and chronic Burkholderia cenocepacia complex (Genomovar IIIA) developed a progressive decline in lung function and general health over a three year period. FEV1 fell from 57% to 25% predicted with a median (range) CRP of 49 mg/L (24–134). Adherence to treatment was variable and his quality of life poor. He continued to decline despite 703 days of IV antibiotics between 02/2011 and 02/2015. CF was diagnosed at the age of 25 years through family screening. He had two siblings with CF, one of whom sadly passed away. The other sibling has started to show signs of deterioration. He is pancreatic sufficient with DF508/R117H mutations and 5T:9T alleles. In 02/2015 he was commenced on ivacaftor which resulted in a dramatic improvement in his general health and exercise tolerance. Sweat chloride fell from 90 to 59 mmol/l, lung function stabilised, BMI increased significantly and median (range) CRP fell to 27 (18.5–74). He was able to discontinue continuous intravenous antibiotic treatment by April 2015 and since then has only required one further course of treatment. His MRC breathlessness score has fallen from grade 4 to grade 2. Whilst ivacaftor has been approved for class III gating mutations it should also be considered for class IV R117H/5T mutations. In patients with severe lung disease, it appears to reduce sweat chloride, stabilise lung function, improve BMI and reduce the number of intravenous antibiotic courses (Ronan et al., J Cyst Fibros 2015:14; e4–5, Carter et al., Chest 2015:148; e72–5). Treatment of CF patients with milder phenotypes is likely to have significant long term benefit and protect against clinical deterioratio