Given her clinical trajectory, a trial of ivacaftor 150 mg bid was initiated at age 19 years after a successful physician appeal to her prescription drug provider, which was based on in vitro data and clinical experience. Following initiation of ivacaftor, she experienced improved spirometry, reaching 100% predicted at peak benefit and a mean improvement rate of 8.1 FEV1% predicted per year (P = .06 vs rate of change in FEV1% predicted prior to ivacaftor) (Fig 1), a reduction of sweat chloride level from 51 mmol/L to 25 mmol/L (obtained 1 month after initiating ivacaftor therapy), reduced frequency of exacerbations (one over a 1-year follow-up period), and improved pulmonary symptoms. She also gained > 4 kg body weight (a 10% improvement in BMI from pre-ivacaftor baseline). Sputum microbiology significantly improved, in that a culture of Mycobacterium abscessus resolved without treatment (confirmed by two serial assessments); P aeruginosa mucoidy also resolved as determined by five sequential sputum cultures, which demonstrated nonmucoid P aeruginosa in two cultures and no Pseudomonas in the other three culture samples). Additionally, the C-reactive protein levels declined from 47.1 mg/L based on historical data to 2.52 mg/L posttherapy. Serial CT scans revealed marked improvement in air trapping and mucous plugging. Multiple ectatic airways decreased in size between the two studies (Fig 2). The Brody score, assessed by a radiologist blinded to CT scan date and treatment data, improved from 58.5 to 42, with improvement in the bronchiectasis component from 24.5 to 21.5, and the air trapping component improved from 16 to 4.5. A marked decrease in large and small airway mucous plugging was seen, with a decrease in the mucous plugging component of the score from 13 to 11.