Efficacy and Safety of Everolimus in Korean Patients with Metastatic Renal Cell Carcinoma Following Treatment Failure with a Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitor

PURPOSE: The purpose of this study is to assess the efficacy and safety of everolimus in Korean patients with metastatic renal cell carcinoma (mRCC) for whom initial treatment with a vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) has failed. MATERIALS AND METHODS: Eligible patients with mRCC (any histology) who had progressed on or were intolerant of VEGFr-TKI therapy received oral everolimus (10 mg dose once daily). Tumor response was reassessed according to Response Evaluation Criteria in Solid Tumors (RECIST). RESULTS: This study included 100 patientswith a median follow-up duration of 10.2 months, a median progression-free survival (PFS) of 4.2 months (95% confidence interval [CI], 3.4 to 5.0 months), and an overall survival of 10.1 months (95% CI, 6.9 to 13.3 months). The most common grade 3 or greater adverse events (AEs) overall were anemia (13%), pneumonitis (9%), hyperglycemia (8%), and stomatitis (6%). While the incidence of pneumonitis was similar (26 cases, 26%) to the reported incidence in Western patients, the Korean presentations were more severe: 10 patients permanently discontinued everolimus due to pneumonitis, including two deaths on treatment. Statistically significant relationships were established between biologic toxicities, hyperglycemia and anemia, and PFS (hyperglycemia vs. non-hyperglycemia: hazard ratio [HR], 0.61; p=0.055 and anemia vs. non-anemia: HR, 0.51; p=0.021). CONCLUSION: Everolimus was effective in Korean patients with mRCC who had failed initial VEGFr-TKI therapy. While everolimus was well tolerated in general and the AE incidence of this study was similar to those of previous reports, severe pneumonitis was common. Hyperglycemia and anemia showed significant correlation with PFS and thus may be potentially useful as prognostic indicators.