In this article, we present data showing that an enzymatic therapy based on a CLytA-DAAO chimera constitutes a new therapeutic strategy for various types of tumors, so it can be used in colon carcinoma and, even more important, in pancreatic carcinoma and glioblastoma, two types of tumors for which there is no effective therapy to date. Here, DAO is linked to exocrine pancreatic carcinoma.