Comparative efficacy of sunitinib versus sorafenib as the first-line treatment for patients with metastatic renal cell carcinoma.

e15080 Background: Currently, sunitinib has been recommended as the primary treatment in the patients with metastatic renal cell carcinoma (mRCC) among the vascular endothelial growth factor tyrosine kinase inhibitor (VEGF TKI). However, there are no published clinical data that compared directly the efficacy of targeted agents in the first line setting, and first-line treatment in mRCC patients is yet to be determined. Methods: To compare the efficacy and toxicities between sorafenib and sunitinb, clinical database was used to identify all patients with mRCC treated with VEGF TKIs in Asan Medical Center from April 2005 to March 2011. Among 304 patients, we identified 49 and 220 patients who were treated first with sorafenib and sunitinib, respectively. Results: The patients in the sorafenib group were older than those in the sunitinib group (62 vs 56.5 years, p=0.019). Disease control rate (DCR) of 82% was achieved in both groups. After a median follow-up duration of 49 months, progression free survival (PFS) and overall survival (OS) were not significantly different (sorafenib vs sunitinib, PFS; 8.6 months vs 9.9 months, p=0.948, OS; 25.7 months and 22.6 months, p=0.774). The patients treated with sorafenib have required dose reduction due to toxicities less frequently than those treated with sunitinib (37% vs 54%, p=0.034). Hematologic toxicities of grade 3 or 4 were more common in sunitinib group (4.2% vs 44.6%, p<0.001), and also was grade 3 or 4 hypertension, although it was not statistically significant (4.2% vs 13.7%, p=0.06). Age (> 60 years), duration from diagnosis to treatment (less than 1 year), Anemia, Neutrophilia, thorombocytosis, bone and liver metastases were independent prognostic factors affecting OS. Multivariate analysis also showed first-line VEGF TKI did not affect OS [hazard ratio (HR, sorafenib vs sunitinib) = 0.94, p=0.774]. Conclusions: Sorafenib showed comparable efficacy to sunitinb and demonstrated superiority in toxicities in the treatment of mRCC patients.