The present invention relates to the use of the combination of tyrosine phosphate inhibitors AMN107 and PKC412 for the preparation of a drug for the treatment of a mast cell-related proliferative disease. The present invention is also drawn to a combination treatment of a tyrosine phosphate inhibitor and a TK-inhibitor that is effective against a mast cell-related proliferative disease, including especially systemic mastocytosis (SM) including aggressive SM (ASM) and mast cell leukemia (MCL).
