Sequential Treatment Based on Sunitinib and Sorafenib in Patients with Metastatic Renal Cell Carcinoma

Objectives: The aim of our study was to evaluate the outcome of alternative sequences of sunitinib followed by sorafenib versus sorafenib followed by sunitinib therapies in patients with metastatic renal cell carcinoma (mRCC). Materials and Methods: This single-center study analyzed patients with mRCC on systemic therapy between January 2005 and August 2011. Patients were treated with the recommended first-line therapy (sunitinib, sorafenib, pazopanib, or immunotherapy) until progression or intolerable toxicity and afterward switched to another guideline-recommended systemic therapy. Only patients starting first-line therapy on either sorafenib or sunitinib and switching to the other of these drugs were included in this analysis. Results: Out of 266 patients (females: 85, males: 181) with a median age of 57.1 years (30 - 76 years), 57 patients with a sequence of sunitinib and sorafenib were identified. First-line sorafenib therapy was followed by sunitinib (So-Su) in 32 patients; sunitinib was followed by sorafenib (Su-So) in 25 patients. Progression-free survival (PFS) for patients with first-line sorafenib was 11.6 months and was 8.7 months for sunitinib. Overall survival (OS) rates for Su-So was 118.8 months and 83.3 months with So-Su (p = 0.82). No new safety signals were detected. Conclusion: None of the therapeutic first-line approaches was superior to the other. Sequencing tyrosine kinase inhibitor (TKI) therapy seems to be effective in mRCC and superior to single-line therapy. Further studies should focus on the efficacy of single treatment lines rather than treatment sequences to estimate more potent drugs based on PFS rather than overall survival (OS).