Multi-Target CFTR Modulators Endowed with Multiple Beneficial Side Effects for Cystic Fibrosis Patients: Toward a Simplified Therapeutic Approach

Cystic fibrosis (CF) is a multi-organ disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR). In addition to respiratory impairment due to mucus accumulation, viruses and bacteria triggers acute pulmonary exacerbations, accelerating disease progression and mortality rate. Treatment complexity increases with patients' age and simplifying the therapeutic regimen represents one of the key priorities in CF. We have recently reported the discovery of multi-target compounds able to "kill two birds with one stone" by targeting F508del-CFTR and PI4KIIIβ and thus acting simultaneously as correctors and broad-spectrum enterovirus (EV) inhibitors. Starting from these preliminary results, we report herein a hit-to-lead optimization and multi-dimensional SAR study that led to compound 23a. This compound showed good antiviral and F508del-CFTR correction potency, additivity/synergy with lumacaftor and a promising in vitro ADME profile. It was well tolerated in vivo with no sign of acute toxicity and histological alterations in key biodistribution organs.