The present invention relates to compositions, methods, uses and kits for treating cancer. In particular, the invention relates to compositions and methods of treating cancer in a subject comprising administering chymotrypsinogen in certain amounts, for example greater than about 0.1mg/kg, and trypsinogen in an amount, for example, greater than about 0.02 mg/kg, thereby treating cancer. The invention also relate to compositions and methods for treating cancer in a subject comprising chymotrypsinogen and trypsinogen wherein the weight ratio of chymotrypsinogen : trypsinogen is greater than 8:1.