The use of ivacaftor in an adult with severe lung disease due to cystic fibrosis (ΔF508/G551D).

We report on an adult with cystic fibrosis (ΔF508/G551D) with severe lung disease (forced expiratory volume (FEV1) in one second 24% predicted) who was admitted for a pulmonary exacerbation. He was managed with maximal medical therapy, but did not have significant improvement until after he was started on ivacaftor on hospital day 15. He subsequently had significant improvement in lung function with normalization of hypercarbia, oxygen saturation on room air, and increase in FEV1 to 36% predicted. Prior to use of ivacaftor he was being assessed for a lung transplant. However, after ivacaftor therapy for 6 months, he is no longer considering this treatment modality due to his improvement of lung function and functional status.