Nanomolar-potency ‘co-potentiator’ therapy for cystic fibrosis caused by a defined subset of minimal function CFTR mutants

• Published in: Scientific reports Vol. 9; no. 1; pp. 17640 - 12
• Main Authors: Phuan, Puay-Wah, Tan, Joseph-Anthony, Rivera, Amber A., Zlock, Lorna, Nielson, Dennis W., Finkbeiner, Walter E., Haggie, Peter M., Verkman, Alan S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.11.2019; Nature Publishing Group
• Subjects: 631/154; 631/45/269/1147; Cell culture; Chloride conductance; Clonal deletion; Cystic fibrosis; Cystic Fibrosis - drug therapy; Cystic Fibrosis - genetics; Cystic Fibrosis - metabolism; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - metabolism; Drug Discovery; Drug Synergism; Epithelial cells; Gene deletion; High-Throughput Screening Assays; Humanities and Social Sciences; Humans; multidisciplinary; Mutation; Piperidine; Piperidines - therapeutic use; Pyrazoles - therapeutic use; Science; Science (multidisciplinary); Structure-Activity Relationship
• DOI: 10.1038/s41598-019-54158-2
• ISSN: 2045-2322

Available CFTR modulators provide no therapeutic benefit for cystic fibrosis (CF) caused by many loss-of-function mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel, including N1303K. We previously introduced the concept of ‘co-potentiators’ (combination-potentiators) to rescue CFTR function in some minimal function CFTR mutants. Herein, a screen of ~120,000 drug-like synthetic small molecules identified active co-potentiators of pyrazoloquinoline, piperidine-pyridoindole, tetrahydroquinoline and phenylazepine classes, with EC 50 down to ~300 nM following initial structure-activity studies. Increased CFTR chloride conductance by up to 8-fold was observed when a co-potentiator (termed ‘Class II potentiator’) was used with a classical potentiator (‘Class I potentiator’) such as VX-770 or GLPG1837. To investigate the range of CFTR mutations benefitted by co-potentiators, 14 CF-associated CFTR mutations were studied in transfected cell models. Co-potentiator efficacy was found for CFTR missense, deletion and nonsense mutations in nucleotide binding domain-2 (NBD2), including W1282X, N1303K, c.3700A > G and Q1313X (with corrector for some mutations). In contrast, CFTR mutations G85E, R334W, R347P, V520F, R560T, A561E, M1101K and R1162X showed no co-potentiator activity, even with corrector. Co-potentiator efficacy was confirmed in primary human bronchial epithelial cell cultures generated from a N1303K homozygous CF subject. The Class II potentiators identified here may have clinical benefit for CF caused by mutations in the NBD2 domain of CFTR.