Outcomes of Patients With Metastatic Non–Clear-Cell Renal Cell Carcinoma Treated With Pazopanib

Abstract

BackgroundPazopanib is associated with increased progression-free survival (PFS) in clear-cell renal cell carcinoma (RCC) and has become a standard of care in this disease. The drug is used in metastatic non–clear-cell RCC, but data on outcomes in this setting are limited. Patients and MethodsWe conducted a retrospective data analysis of records of consecutive metastatic non–clear-cell RCC patients who received pazopanib in front-line and salvage settings between November 2009 and November 2012. Tumor response rate was assessed by a blinded radiologist using Response Evaluation Criteria in Solid Tumors version 1.1. PFS and overall survival (OS) times were estimated using Kaplan–Meier methods. ResultsTwenty-nine patients were identified with non–clear-cell metastatic RCC, 9 received pazopanib in the front-line setting, 20 in the salvage setting after progression of disease with other targeted therapies. Seven patients (24%) had papillary RCC, 4 (14%) had chromophobe, 5 (17%) had unclassified histopathology, and 13 (45%) had other subtypes including collecting duct, translocation Xp11.2, and various subtypes with sarcomatoid differentiation. All patients discontinued pazopanib before analysis. Median PFS was 8.1 months (95% CI, 5.7-NA [not available]) in the front-line group, and 4 months (95% CI, 2.1-9.9) in the salvage group. Median OS was 31 months (95% CI, 9.2-NA) in the front-line group, and 13.6 months (95% CI, 6.4-NA) in the salvage group. ConclusionPazopanib showed efficacy in patients with metastatic non–clear-cell RCC in the front-line and salvage settings. Toxicity was mild to moderate and manageable. Further studies are needed to evaluate pazopanib's role in non–clear-cell RCC in terms of efficacy and safety.