Endostatin Goes to the Clinic

Abstract

BIOMEDICINE Solid tumors require a blood supply for growth, and many new cancer therapies are being formulated to disrupt that blood supply by targeting the tumor vasculature. One such therapeutic agent, endostatin, has attracted an extraordinary degree of public interest. Endostatin, a fragment of collagen, potently inhibits the growth of capillary endothelial cells in culture, and in preclinical studies with mice it has shown outstanding anticancer activity. Eder et al. and Herbst et al. report the much-anticipated results of two phase I clinical trials of endostatin. The good news is that in both studies, which involved a total of 40 patients with advanced and otherwise incurable solid tumors, endostatin had no adverse side effects. One disappointing result was the finding that only three patients showed signs of an anti-tumor response, and in all cases the response was minor. Phase I trials are not specifically designed to measure drug efficacy, however, and the authors suggest that optimization of endostatin delivery methods or use of endostatin in combination with other therapies or both may increase the response rate in future trials. — PAK J. Clin. Oncol . 20 , 10.1200/JCO.2002.02.082; 10.1200/JCO.2002.11.061; 10.1200/JCO.2002.05.102 (2002).