Vapendavir diphosphate (BTA798 diphosphate) is a potent enteroviral capsid binder (CB). Vapendavir diphosphate (BTA798 diphosphate) possesses potent antiviral activity for enterovirus 71 (EV71) replication, with EC50 values of 0.5-1.4 μM in different EV71 strains.