Changes in nutrition and growth status in young children in the first 12 weeks of ivacaftor therapy

Background: Highly effective CFTR modulators improve nutritional status and are of particular importance among younger children experiencing rapid growth. This study was designed to examine CFTR modulator associated changes in nutritional and other extrapulmonary outcomes in children 4-24 months of age with ivacaftor treatment over 12 weeks.Methods: Children 4-24 months were recruited from US and Canadian CF Centers. Eligible children were ivacaftor naive and approved to start therapy. Anthropometrics, diet, sleeping energy expenditure (SEE), nutrition biomarkers, pancreatic status, serum and fecal calprotectin, serum bile acids, plasma fatty acids were measured. Changes from baseline at 6 and 12 weeks were examined using mixed effects linear regression modeling.Results: Fifteen participants enrolled (40% male). Weight-for-age z-scores increased at 6 ( p = 0.03) and 12 weeks ivacaftor therapy ( p < 0.001) compared to baseline. Plasma docosatetraenoic acid (DTA), total saturated fatty acids increased at 6 weeks ( p = 0.02) and 12 weeks ( p = 0.009). At 12 weeks, serum CO2 concentration decreased ( p = 0.002), serum urea nitrogen increased ( p = 0.01) and fecal elastase increased ( p = 0.02) compared to baseline. Bile acids, deoxycholic acid increased ( p = 0.03) and ursodeoxycholic acid decreased ( p = 0.02) after 12 weeks. Plasma total fatty acids, palmitic acid, mead, and docosatetraenoic acid (DTA) increased after 12 weeks ( p = 0.02, p = 0.002 and p = 0.04, respectively). Plasma total saturated fatty acids increased at 6 weeks ( p = 0.02) and 12 weeks ( p = 0.009). Dietary intake ( p = 0.04) and percent kcal from protein ( p = 0.04) increased after 12 weeks compared to baseline.Conclusions: Overall, younger children experienced favorable changes in nutritional and growth status in the first 12 weeks of ivacaftor therapy.(c) 2023 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.