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Chemistry: Generation 2.5

IONIS-ENAC-2.5Rx is an investigational antisense medicine designed to reduce the production of epithelial sodium channel (ENaC) protein in the lung. ENaC is believed to be hyperactive in cystic fibrosis (CF), which is caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. Reduction of ENaC with antisense oligonucleotides (ASOs) in preclinical mouse models of cystic fibrosis lung disease leads to significant decrease of mucus accumulation and inflammation, hallmarks of CF lung disease, and improved lung function. This drug is delivered to the lung via aerosol delivery, which results in broad distribution of ASO in the lung with minimal systemic exposure.

About Cystic Fibrosis

Cystic fibrosis (CF) is one of the most common life-threatening genetic diseases, affecting ~30,000 people within US and about 70,000 worldwide. It is an autosomal recessive disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a chloride channel expressed in epithelial cells in the lung, liver, pancreas, digestive tract, reproductive tract, and skin. Although CF is a multisystem disease, the main cause of morbidity and mortality is lung disease that is characterized by small airway obstruction due to mucus accumulation, decreased mucociliary clearance, and subsequent inflammation and infections.

Select Publications

1. Crosby, J.R. et al. (2017) Inhaled ENaC antisense oligonucleotide ameliorates cystic fibrosis-like lung disease in mice. Journal of Cystic Fibrosis , Volume 16 , Issue 6 , 671 – 680

Clinical trial post

Safety and efficacy have not been evaluated by any regulatory authorities for the indications described.