The present invention relates to novel crystalline salts of a CDC7 or CDC7/CDKs inhibitor, to a novel crystal form of the corresponding free base, to a process for their preparation, to hydrates, solvates and polymorphs of such new salt forms, to their use in therapy and to pharmaceutical compositions containing them. Such crystal salts are selected from L-asparate, hemifumarate, hydrochloride, maleate, mesylate, sulfate, L-tartrate or phosphate salts of 5-(2-amino-pyrimidin-4-yl)-2-(2,4-dichloro-phenyl)-1H-pyrrole-3-carboxylic acid amide.
