The invention is a compound represented by Structural Formula (I):or a pharmaceutically acceptable salt thereof. Values for the variables are provided herein. Also included is a phannaceutical composition comprising the compound represented by Structural Fonnula (I) and a pharmaceutically acceptable carrier or diluent and methods of treating a subject with cancer with the compound of Structural Formula (I).本發明關於一種由結構式(I)表示之化合物:或其醫藥學上可接受之鹽。本文提供該等變量之值。本發明亦包括一種醫藥組成物,其包含由結構式(I)表示之化合物及醫藥學上可接受之載劑或稀釋劑,以及用結構式(I)之化合物治療患有癌症之個體的方法。