 It is orally administered and, because it is effective at nanomolar concentrations, it can be administered once daily.Vicriviroc binds to a small hydrophobic pocket between the transmembrane helices near the extracellular surface of the CCR5 receptor.Binding to this pocket induces a conformational change of the extracellular segment of CCR5 and prevents binding of gp120 to the target cell, consequently preventing the virus from entering the target cell at all.