Disclosed are novel pharmaceutical compositions containing N-{3-[3-cyclopropyl-5-(2-fluoro-4-iodo-phenylamino)-6,8-dimethyl-2,4,7-trioxo-3,4,6,7-tetrahydro-2H-pyrido[4,3-d]pyrimidin-1-yl]phenyl}acetamide dimethyl sulfoxide solvate, methods of using the compositions in therapy and processes for preparing the same.本發明係揭示包含N-{3-[3-環丙基-5-(2-氟-4-碘-苯基胺基)-6,8-二甲基-2,4,7-三側氧基-3,4,6,7-四氫-2H-吡啶并[4,3-d]嘧啶-1-基]苯基}乙醯胺二甲基亞碸溶劑化物之新穎的醫藥組成物、使用此組成物用於治療之方法及製備此組成物之方法。