Enzyme and proton-activated prodrugs for a selective cancer therapy.

This review is a survey of two approaches for a selective anticancer therapy that are based on a specific cleavage of specially designed non-toxic prodrugs with the liberation of a cytotoxic compound either by antibody-enzyme conjugates targeted to tumor-associated antigens or by acid-catalyzed hydrolysis of the prodrugs due to the increased concentration of hydronium ions in malignant tissue under hyperglycemic conditions. Herein, the design, synthesis and the biological testing of prodrugs are described.