High-Throughput Functional Assay in Cystic Fibrosis Patient-Derived Organoids Allows Drug Repurposing

Cystic fibrosis (CF) is a rare hereditary disease caused by mutations in the CFTR gene. Recent therapies enable effective restoration of CFTR function of the most common F508del CFTR mutation. This shifts the unmet clinical need towards people with rare CFTR mutations such as nonsense mutations, of which G542X and W1282X are most prevalent. CFTR function measurements in patient-derived cell-based assays played a critical role in preclinical drug development for CF and may play an important role to identify new drugs for people with rare CFTR mutations.Here, we miniaturized the previously described forskolin induced swelling (FIS) assay in intestinal organoids from a 96-wells to a 384-wells plate screening format. Using this novel assay, we tested CFTR increasing potential of a 1400-compound FDA-approved drug library in organoids from donors with W1282X/W1282X CFTR nonsense mutations.The 384-wells FIS-assay demonstrated uniformity and robustness based on CV and Z’-factor calculations. In the primary screen, the top 5 compound combinations that increased CFTR function all contained at least one statin. In the secondary screen, we indeed verified that four out of the five statins, Mevastatin; Lovastatin; Simvastatin and Fluvastatin increased CFTR function when combined with CFTR modulators. Statin-induced CFTR rescue was W1282X specific, as increased CFTR function was not shown for patient-derived organoids harbouring R334W/R334W and F508del/F508del mutations.Future studies should focus on elucidating genotype specificity and mode-of-action of statins into more detail. This study exemplifies proof-of-principle of large-scale compound screening in a functional assay using patient derived organoids.Graphical abstract