Disclosed is a compound of formula (I): crystalline forms thereof, and solvates thereof; pharmaceutical compositions comprising a pharmaceutically effective amount of the compound of formula (I), or a crystalline form thereof, or a solvate thereof, and a pharmaceutically acceptable carrier or diluent; and the use of a compound of formula (I), or a crystalline form thereof, or a solvate thereof, for treating a patient suffering from, or subject to, a pathological condition capable of being ameliorated by inhibiting an E1 activating enzyme, particularly NAE, including, e.g., cancer.