Tong K, Barker D, France M, et al. - Researchers performed this case control study to investigate if pulmonary exacerbation rate in cystic fibrosis (CF) patients (> 12 years) homozygous for Phe508del CFTR mutation and with ppFEV1 < 40% could be reduced by treatment with lumacaftor/ivacaftor (LUM/IVA). This study also included controls who were matched for age, gender and ppFEV1, and carried mutations ineligible for LUM/IVA. From 7 Australian CF centres, the data on 105 patients, including 72 on LUM/IVA and 33 controls, were obtained. Findings revealed a substantially lower rate of pulmonary exacerbations, and prolonged time to first exacerbation, as well as slowing of the rate of decline of ppFEV1 in participants with severe lung disease treated with LUM/IVA. However, unacceptably frequent adverse reactions which led to a very high discontinuation rate were also observed in relation to LUM/IVA treatment.