#$%^&*AU2015201929A120150507.pdf#####H:uhiitmtovmNPOrtbl DjCkDAR ,766tdv {-5/420J ABSTRACT The present invention is directed to a compound represented by Structural Formula (I) or a pharmaceutically acceptable salt thereof The variables for Structural Fornnula (I) are defined herein. Also described is a pharmaceutical composition comprising the compound of Structural Formula (I) and its therapeutic use. H3CN ICH3 H H OH NH2 H O H H 0 (I