The invention relates to novel solvates of methyl{4,6-diamino-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-B]pyridine-3-yl]pyrimidin-5-yl}carbamate, in particular the semi-ethanol solvate of the formula (Ia), to a method for the production thereof, to medications comprising the same, and to the use thereof for treating illnesses.