Use of CFTR modulators in special populations, part 2: Severe lung disease

Safety and efficacy data surrounding cystic fibrosis transmembrane regulator (CFTR) modulator administration for people with CF (pwCF) and severe lung disease elect has remained unclear as a result of exclusion from key trials. A scoping review of English language articles from the period of 1 January 2012, to 31 July 2023 was conducted utilizing PubMed and EmBase databases with the following terms: "severe lung disease" OR "advanced lung disease" AND "ivacaftor OR lumacaftor OR tezacaftor OR elexacaftor"; "cystic fibrosis transmembrane conductance regulator" AND "off label drug use." Search results were reviewed by title and abstract for relevance. Twenty articles specific to CFTR modulator use in the setting of severe lung disease were included for review, with few specific to pediatric-aged pwCF. PwCF and severe lung disease experienced significant improvement in pulmonary function, body weight, number of IV antibiotic days, and quality of life. A few studies reported a transient decline in pulmonary function among pwCF shortly after LUM/IVA initiation. However, preemptive reductions in the dose of LUM/IVA may mitigate this reaction. ELE/TEZ/IVA utilization in pwCF and severe lung disease appears to be devoid of the transient decline in pulmonary function observed with LUM/IVA while providing the same clinical benefit. Current available data regarding use of CFTR modulators in pwCF and severe lung disease is reassuring; however, there remains a lack data regarding outcomes among the pediatric population including long-term outcomes. Therefore, treatment decisions should be individualized and coproduced.