the invention relates to a highly active , highly specific urokinase inhibitor which is suitable for therapeutic applications and can be synthesized in an extremely simple manner . surprisingly , it was found that amidino benzylamine derivatives , especially 4 - amidino - benzylamine , with two bonded amino acids represent a new group of highly active and very selective upa inhibitors . the urokinase inhibitors can be used in medical applications , e . g . in the treatment of malign tumors such as in cases of metastatic spread .