This application relates to various crystalline forms of 5-bromo-2,6-di(1H-pyrazol-1-yl)pyrimidin-4-amine and salt thereof, 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 carcinomas, specifically lung cancer and more specifically non-small cell lung cancer.