The availability of angiogenesis inhibitors for advanced kidney cancer has clearly been a major step forward in the treatment of the disease. Unfortunately for most patients, the cancer does eventually progresses, even while on treatment. For this reason, researchers are developing new therapies and treatment combinations to attack kidney cancer from different directions.

Among the new targets for therapy are molecules called integrins that are required for tumor angiogenesis. Volociximab, an antibody therapy that is designed to neutralize integrins, showed very promising activity in a clinical trial in kidney cancer patients who had received a number of previous therapies to treat their tumors.⁸ In this study, 80% of patients who received volociximab had their tumors stop growing.

For patients with kidney cancer whose disease progresses on one antiangiogenic therapy, there is evidence that they may benefit from switching to a different antiangiogenic drug. Several recent studies, for example, have shown that treatment with either sunitinib or sorafenib is feasible in patients who have progressed on the other agent.^{9, 10, 11} Some studies have also shown that patients can benefit from treatment with sunitinib if their cancer progresses while being treated with bevacizumab.¹² Because each angiogenesis inhibitor works slightly differently, there is hope that sequencing or combining agents can prolong response in some patients with kidney cancer.