Anti-vascular
tumor therapy represents a promising new strategy for
cancer treatment. Anti-vascular treatment may be divided in anti-angiogenic and vascular targeting
therapy. Whereas
anti-angiogenic drugs aim on the inhibition of new vessel formation, vascular targeting compounds are designed to selectively destruct preexisting
tumor blood vessels leading to secondary
tumor cell death. Both
anti-angiogenic drugs and vascular targeting agents have proven effective anti-tumoral activity in numerous preclinical studies over the last decade. In vivo, a combination with anti-vascular
tumor therapy enhances the effects of other treatment modalities as chemo- and
radiotherapy. Phase I clinical studies revealed a number of well-tolerated candidates. As monotherapy, however, anti-angiogenic treatment lacked efficacy in randomized clinical studies so far. In contrast, combination of anti-angiogenic
therapy with
chemotherapy was highly effective in an encouraging, large randomized phase III trial on metastatic
colorectal cancer. This review will outline recent advances in the preclinical and clinical development of anti-vascular
therapy with focus on vascular targeting. Conceptual differences between anti-angiogenic and vascular targeting
therapies will be discussed with emphasis on specific problems and pitfalls in the conversion into the clinic.