Pritelivir-d 4 -1 (AIC316-d 4 -1) is deuterium labeled Pritelivir. Pritelivir (AIC316), an inhibitor of the viral helicase-primase complex , exhibits antiviral activity in vitro and in animal models of herpes simplex virus ( HSV ) infection. Pritelivir is active against herpes simplex virus types 1 and 2 ( HSV-1 and HSV-2 ) with the IC 50 of 0.02 μM against HSV1-2.