1. Pharmacological rescue of the G85E CFTR variant by preclinical and approved modulators
- Author
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Valeria Tomati, Valeria Capurro, Emanuela Pesce, Cristina Pastorino, Elvira Sondo, Mariateresa Lena, Anna Borrelli, Federico Cresta, Stefano Pantano, Francesca Collini, Pietro Ripani, Vito Terlizzi, Cristina Fevola, Stefano Costa, Maria Cristina Lucanto, Federico Zara, Tiziano Bandiera, Renata Bocciardi, Carlo Castellani, Luis J. V. Galietta, and Nicoletta Pedemonte
- Subjects
CFTR ,correctors ,gating ,theratyping ,nasal ,modulators ,Therapeutics. Pharmacology ,RM1-950 - Abstract
IntroductionCystic Fibrosis (CF) is a genetic disease due to loss-of-function mutations of the CFTR channel. F508del is the most frequent mutation (70% of alleles in Italy), while other mutations have much lower frequency. Among them, G85E (0.4% frequency globally, 1.13% in Italy) emerges as a mutation characterized by a severe CFTR folding and trafficking defect.MethodsTo investigate the pharmacological responsiveness of the G85E-CFTR variant, we performed a functional and biochemical characterization in heterologous expression systems and ex vivo models based on patient-derived human nasal epithelial cells (HNEC).ResultsOur study demonstrated that treatment of primary airway cells with elexacaftor and tezacaftor causes a significant (although modest) rescue of CFTR function, that reaches 15%–25% of the activity measured in non-CF epithelia. A detrimental effect of chronic treatment with ivacaftor, further limiting G85E rescue, was also observed. A higher rescue of CFTR function, up to 25%–35% of the normal CFTR activity, with no evidence of negative effects upon chronic potentiator treatment, can be achieved by combining elexacaftor with ARN23765, a novel type 1 corrector endowed with very high potency. Importantly, dose-response relationships suggest that G85E might alter the binding of type 1 correctors, possibly affecting their affinity for the target.DiscussionIn conclusion, our studies suggest that novel combinations of modulators, endowed with higher efficacy leading to increased rescue of G85E-CFTR, are needed to improve the clinical benefit in patients for this variant.
- Published
- 2024
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