Antitumor effects of sunitinib or sorafenib in patients with metastatic renal cell carcinoma who received prior antiangiogenic therapy

Purpose: Antiangiogenic therapy with sunitinib and sorafenib has become the standard of care for patients with advanced renal cell carcinoma. However, the clinical benefit of these agents after prior antiangiogenic therapy has not been defined. Currently, several agents with a putative antiangiogenic mechanism exist and they are often being used in sequence with little to no data regarding activity in a second line or later setting. Materials and Methods: Patients with advanced renal cell carcinoma currently being treated with either sunitinib or sorafenib after receiving I or more prior antiangiogenic agent(s) were investigated in a retrospective analysis. Time to progression and the overall response rate by Response Evaluation Criteria in Solid Tumors were evaluated. Results: Thirty patients receiving current sunitinib (16 patients) or sorafenib (14 patients) were identified. Patients received 1 or more prior antiangiogenic therapies: thalidomide, lenalidomide, bevacizumab, volociximab, AG13736, sorafenib or sunitimb. Of 16 patients treated with sunitinib 13 had some degree of tumor shrinkage, including 9 with a partial response by Response Evaluation Criteria in Solid Tumors. Of 14 patients treated with sorafenib 10 had some degree of tumor shrinkage, including 1 with a partial response. The median time to progression for the entire cohort was 10.4 months. Conclusions: Significant antitumor activity is observed when sorafenib or sunitinib are used in patients who have failed prior therapy with an antiangiogenic agent. Prior response to an antiangiogenic agent does not appear to predict subsequent clinical benefit to either sunitinib or sorafenib.