The present invention relates to 6-(1-methyl-1H-pyrazol-4-yl)-2-{3-[5-(2-morpholin-4-yl-ethoxy)-pyrimidin-2-yl]-benzyl}-2H-pyridazin-3-one dihydrogenphosphate, its solvates and crystalline modifications thereof. The present invention further relates to processes of manufacturing these crystalline modifications as well as their use in the treatment and/or prophylaxis of physiological and/or pathophysiological conditions, which are caused, mediated and/or propagated by the inhibition, regulation and/or modulation of signal transduction of kinases, in particular by the inhibition of tyrosine kinases, e.g. pathophysiological conditions such as cancer.
