Evolution of HCV NS4B Inhibitors

NS4B has remained for a long time an undisclosed target within the HCV drug discovery programs. However, impressive drug discovery efforts from 2005 to 2016 led to the identification of different chemical classes targeting NS4B as effective anti-HCV agents, and some of them act by impairing AH2-mediated membranous web formation or RNA-binding property. This book chapter aims to discuss research published on NS4B inhibitors focusing on hit identification and hit-to-lead optimization, also with respect to pharmacokinetic properties and structure-activity relationships raised for the different chemical classes taken into account. To date, the only clinical trial conducted with molecules targeting NS4B was focused on clemizole hydrochloride. However, even if NS4B ligands are not currently used in therapy, they can serve in the near future as new weapons to combat resistance to the current therapy.