The invention relates to solid forms of the Formula (I) wherein X is -PO(OH)2, -PO(OH)O-M+, or -PO(O-)2‧2M+,wherein M is a monovalent cation such as Na+, K+, Li+, or NH4+. The invention also provides pharmaceutically acceptable compositions comprising the solid form of he compound and method of using the compositions in the treatment of various disorders.本發明係關於式(I)之固體形式:其中X係-PO(OH)2、-PO(OH)O-M+或-PO(O-)2‧2M+,其中M係單價陽離子,例如Na+、K+、Li+或NH4+。本發明亦提供包括該化合物之固體形式之醫藥上可接受之組合物及使用該等組合物治療各種病症之方法。