Biological Characterization of F508delCFTR Protein Processing by the CFTR Corrector ABBV-2222/GLPG2222

Cystic fibrosis (CF) is the most common monogenic autosomal recessive disease in Caucasians caused by pathogenic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (CFTR). Significant small molecule therapeutic advances over the past two decades have been made to target the defective CFTR protein and enhance its function. To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in CF, two biomolecular activities are required, namely, correctors to increase the amount of properly folded F508delCFTR levels at the cell surface and potentiators to allow the effective opening, i.e., function of the F508delCFTR channel. Combined, these activities enhance chloride ion transport yielding improved hydration of the lung surface and subsequent restoration of mucociliary clearance. To enhance clinical benefits to CF patients, a complementary triple combination therapy consisting of two corrector molecules, type 1 (C1) and type 2, with additive mechanisms along with a potentiator are being investigated in the clinic for maximum restoration of mutated CFTR function. We report the identification and in vitro biologic characterization of ABBV-2222/GLPG2222 (4-[(2R,4R)-4-({[1-(2,2-difluoro-1,3-benzodioxol-5-yl)cyclopropyl]carbonyl}amino)-7-(difluoromethoxy)-3,4-dihydro-2H-chromen-2-yl]benzoic acid),-a novel, potent, and orally bioavailable C1 corrector developed by AbbVie-Galapagos and currently in clinical trials-which exhibits substantial improvements over the existing C1 correctors. This includes improvements in potency and drug-drug interaction (DDI) compared with 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl) cyclopropanecarboxamido)-3-methylpyridin-2-yl)benzoic acid (VX-809, Lumacaftor) and improvements in potency and efficacy compared with 1-(2,2-difluoro-1,3-benzodioxol-5-yl)-N-[1-[(2R)2,3-dihydroxypropyl]-6-fluoro-2-(1-hydroxy-2-methylpropan-2-yl) indol-5-yl]cyclopropane-1-carboxamide (VX-661, Tezacaftor). ABBV-2222/GLPG2222 exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR with an EC50 value < 10 nM. SIGNIFICANCE STATEMENT To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in cystic fibrosis, AbbVie-Galapagos has developed ABBV-2222/GLPG2222, a novel, potent, and orally bioavailable C1 corrector of this protein. ABBV-2222/GLPG2222, which is currently in clinical trials, exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR and substantial improvements over the existing C1 correctors.