Recovery of lung function following a pulmonary exacerbation in patients with cystic fibrosis and the G551D-CFTR mutation treated with ivacaftor

Abstract

Background

Pulmonary exacerbations (PEx) are associated with acute loss of lung function that is often not recovered after treatment. We investigated lung function recovery following PEx for ivacaftor- and placebo-treated subjects.

Methods

Short- and long-term pulmonary function recovery data after PEx were summarized from a placebo-controlled trial in 161 cystic fibrosis patients ≥ 12 years old with the G551D-CFTR mutation (NCT00909532). Short-term recovery was measured 2 to 8 weeks after treatment, and long-term recovery was determined at the end-of-study, both compared with baseline measured just prior to the PEx.

Results

Fewer patients receiving ivacaftor experienced a PEx than patients receiving placebo (33.7% vs. 56.4%; P = 0.004) and had a lower adjusted incidence rate of PEx (0.589 vs. 1.382; P < 0.001). The proportion of PEx followed by full short-term recovery of percent predicted forced expiratory volume in 1 s was similar (ivacaftor vs. placebo, 57.1% vs. 53.7), as was the proportion of patients having long-term recovery (46.4% vs. 47.7%).

Conclusions

Ivacaftor treatment reduces the frequency of PEx but does not improve on the rate of complete lung function recovery after PEx when compared with placebo.