Background:

Ivacaftor (VX-770) is a potent and orally bioavailable small molecule potentiator of cystic fibrosis transmembrane conductance regulator (CFTR). Studies in both G551D- and F508del-CFTR expressing cells have shown VX-700 combined with forskolin, but not VX-700 alone, has significantly increased CFTR-mediated Cl-secretion. The EC50 values of VX-700 in G551D- and F508del-CFTR are 100 nM and 25 nM, respectively^[1].

VX-770 has been reported to reduce ENaC-mediated Na+ absorption and increase the amount of fluid on the apical surface in human CF bronchial epithelia (HBE) carrying G551D/F508del^[1]. VX-770 combined with OAG has been shown to increase G551D-CFTR activity and OAG-dependent Ca2+ in?ux and in Chinese hamster ovary (CHO) cells^[2].

参考文献:
1. Van Goor F1, Hadida S, Grootenhuis PD, Burton B, Cao D, Neuberger T, Turnbull A, Singh A, Joubran J, Hazlewood A, Zhou J, McCartney J,Arumugam V, Decker C, Yang J, Young C, Olson ER, Wine JJ, Frizzell RA, Ashlock M, Negulescu P. Rescue of CF airway epithelial cell function in vitro by a CFTR potentiator, VX-770. Proc Natl Acad Sci U S A. 2009 Nov 3;106(44):18825-30.
2. Vachel L1, Norez C, Becq F, Vandebrouck C. Effect of VX-770 (ivacaftor) and OAG on Ca2+ influx and CFTR activity in G551D and F508del-CFTR expressing cells. J Cyst Fibros. 2013 Dec;12(6):584-91