This application relates to various crystalline forms of 4-(2-((1R,2R)-2-hydroxycyclohexylamino)benzothiazol-6-yloxy)-N-methylpicolinamide hydrochloride salts as well as compositions and methods of using the same. In some embodiments the crystalline forms also contain water (“hydrates”). These materials are useful in the treatment of various diseases, including glioblastoma multiforme, breast cancer, pancreatic cancer and other solid tumors.
