Open AccessIvacaftor in People with Cystic Fibrosis and a 3849+10kb C→T or D1152H Residual Function Mutation
Author(s) -
Eitan Kerem,
Malena CohenCymberknoh,
Reuven Tsabari,
Michael Wilschanski,
Joel Reiter,
David Shoseyov,
Alex GilelesHillel,
Thea Pugatsch,
Jane C. Davies,
Christopher Short,
Clare Saunders,
Cynthia DeSouza,
James C. Sullivan,
Jamie R. Doyle,
Keval Chandarana,
Nils Kinnman
Publication year - 2021
Publication title -
annals of the american thoracic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 114
eISSN - 2329-6933
pISSN - 2325-6621
DOI - 10.1513/annalsats.202006-659oc
Subject(s) - ivacaftor , cystic fibrosis , medicine , cystic fibrosis transmembrane conductance regulator , crossover study , placebo , clinical endpoint , pulmonary function testing , mutation , clinical trial , pathology , biology , genetics , alternative medicine , gene
Rationale: Ivacaftor's clinical effects in the residual function mutations 3849 + 10kb C→T and D1152H warrant further characterization. Objectives: To evaluate ivacaftor's effect in people with cystic fibrosis aged ≥6 years with 3849 + 10kb C→T or D1152H residual function mutations and to 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 index 2.5 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 index 2.5 with ivacaftor versus 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 of 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 compared with 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).