Development of prodrugs for enzyme-mediated, tumor-selective therapy.

Anticancer enzyme/prodrug approaches to therapy are designed to activate prodrugs specifically at tumor loci, to achieve antitumor responses with minimal toxicity. The equivocal success of these approaches thus far has led to searches for more efficient combinations. This mini-review evaluates and compares characteristics of seven selected enzyme/prodrug combinations, and discusses goals for future development of effective combinations.