approx. 250x-better substrate for VZV encoded thymidine kinase than ACV • The intracellular concentration of H2G-TP is more than 140x greater than ACV-TP • H2G-TP has a longer Tx than ACV-TP • EPB-348 has excellent activity in the gold-standard in vivo Simian Varicella Virus monkey model Lon. MI *