1. Ivacaftor in People with Cystic Fibrosis and a 3849+10kb C→T or D1152H Residual Function Mutation
- Author
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Malena Cohen-Cymberknoh, Eitan Kerem, Michael Wilschanski, Alex Gileles-Hillel, Christopher Short, C DeSouza, Thea Pugatsch, Reuven Tsabari, Clare Saunders, Joel Reiter, James C. Sullivan, N. Kinnman, David Shoseyov, Jane C. Davies, Jamie R Doyle, and Keval Chandarana
- Subjects
Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,business.industry ,Respiratory System ,rectal organoids ,1103 Clinical Sciences ,medicine.disease ,Gastroenterology ,Cystic fibrosis ,crossover studies ,Ivacaftor ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Internal medicine ,Mutation (genetic algorithm) ,medicine ,Cyst ,residual function mutations ,030212 general & internal medicine ,business ,medicine.drug - Abstract
Rationale: Ivacaftor's clinical effects in the residual function mutations 3849+10kb C →T and D1152H warrant further characterization. Objectives: Evaluate ivacaftor's effect in people with cystic fibrosis aged ≥6 years with 3849+10kb C→T or D1152H residual function mutations; explore the correlation between ivacaftor-induced organoid-based cystic fibrosis transmembrane conductance regulator function measurements and clinical response to ivacaftor. Methods: Participants were randomized (1:1) in this placebo-controlled crossover study; each treatment sequence included two 8-week treatments with an 8-week washout period. The primary endpoint was absolute change in lung clearance index2.5 from baseline through Week 8. Additional endpoints included lung function, patient-reported outcomes, and in vitro intestinal organoid-based measurements of ivacaftor-induced cystic fibrosis transmembrane conductance regulator function. Results: Of 38 participants, 37 completed the study. The primary endpoint was met; the Bayesian posterior probability of improvement in lung clearance index2.5 with ivacaftor vs placebo was >99%. Additional endpoints improved with ivacaftor. Safety findings were consistent with ivacaftor's known safety profile. Dose-dependent swelling was observed in 23/25 viable organoid cultures with ivacaftor treatment. Correlations between ivacaftor-induced organoid swelling and clinical endpoints were negligible to low. Conclusions: In people with cystic fibrosis aged ≥6 years with a 3849+10kb C →T or D1152H mutation, ivacaftor treatment improved clinical endpoints vs placebo; however, there was no correlation between organoid swelling and change in clinical endpoints. The organoid assay may assist in identification of ivacaftor-responsive mutations but in this study did not predict magnitude of clinical benefit for individual people with cystic fibrosis with these two mutations. Clinical trial registered with ClinicalTrials.gov (NCT03068312).
- Published
- 2021