Objective: To assess the efficacy of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies including ivacaftor, tezacaftor/ivacaftor, and elexacaftor/tezacaftor/ivacaftor combinations in the improvement of lung function in patients aged 12 and older with Cystic Fibrosis. Design: Systematic Literature Review Methods: A search was performed in PubMed using the search terms “CFTR modulators in Cystic Fibrosis.” Further parameters set were: published in the last 10 years, Randomized Control Trials, and trials that include participants under 18. Articles were excluded if they did not compare to placebo or had a primary endpoint measurement of FEV₁. Results: The Taylor-Cousar et al study showed CFTR combination therapy had a greater absolute change from baseline in FEV₁ as compared to placebo. The Rowe et al study showed both the ivacaftor and tezacaftor-ivacaftor groups had significant benefits with improved FEV₁ compared to placebo. The Donaldson et al study displayed significant FEV₁ improvements noted with tezacaftor/ivacaftor combination therapy, particularly with higher doses of tezacaftor, indicating a possible dose-related response. The Middleton et al study\u27s absolute change in the percentage of predicted FEV₁ have a statistically significant mean treatment difference of 14.3 points compared to placebo. Conclusion: The use of CFTR modulators increases lung function improving quality of life in those 12 years of age and older with Cystic Fibrosis
