The present invention relates to a novel co-crystal of the compound of formula (I):wherein the co-former molecule is bisphosphate hemihydrate, to processes for the preparation of the co-crystal, to pharmaceutical compositions containing the co-crystal, to the use of such a co-crystal in the manufacture of a medicament for use in the treatment of cancer and to methods of treating such diseases in the human or animal body by administering a therapeutically effective amount of such a co-crystal.
