The present invention relates to the use of N-[2,4-bis(1,1-dimethylethyl)-5-hydroxyphenyl]-1,4-dihydro-4-oxoquinoline-3-carboxamide (Compound 1), solids forms, and pharmaceutical compositions thereof for the treatment of CFTR-mediated diseases, particularly cystic fibrosis, in patients possessing specific genetic mutations. The present invention also relates to the use of Compound 1 in combination with 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-3-methylpyridin-2-yl)benzoic acid (Compound 2), and Compound 1 in combination with (S)-1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)-N-(1-(2,3-dihydroxypropyl)-6-fluoro-2-(1-hydroxy-2-methylpropan-2-yl)-1H-indol-5-yl)cyclopropanecarboxamide (Compound 3), for the treatment of CFTR-mediated diseases, particularly cystic fibrosis, in patients possessing specific genetic mutations. The present invention also relates to solid forms and formulations of Compound 2 or Compound 3 in combination with Compound 1, and pharmaceutical compositions thereof, for the treatment of CFTR-mediated diseases, particularly cystic fibrosis, in patients possessing specific genetic mutations.La présente invention concerne l'utilisation de N-[2,4-bis(1,1-diméthyléthyl)-5-hydroxyphényl]-1,4-dihydro-4-oxoquinoléine-3-carboxamide (Composé 1), ses formes solides et ses compositions pharmaceutiques pour le traitement de troubles à médiation par le régulateur de la perméabilité transmembranaire de la fibrose kystique (CFTR), en particulier la fibrose kystique, chez des patients possédant des mutations génétiques spécifiques. La présente invention concerne également l'utilisation du Composé 1 en combinaison avec l'acide 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-3-méthylpyridin-2-yl)benzoïque (Composé 2), et du Composé 1 en combinaison avec le (S)-1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)-N-(1-(2,3-dihydroxypropyl)-6-fluoro-2-(1-hydroxy-2-méthylpropan-2-yl)-1H-indol-5-yl)cyclopropanecarboxamide (Composé 3), pou