Comparative effectiveness of pazopanib and sunitinib as first-line therapy for patients with advanced/metastatic renal cell carcinoma in a U.S. community oncology setting.

Abstract

567 Background: The COMPARZ trial demonstrated that pazopanib was non-inferior to sunitinib regarding their efficacy as first line of therapy (LOT) for advanced/metastatic RCC (aRCC). However, no studies have compared the effectiveness of pazopanib to sunitinib outside the clinical trial setting. The purpose of this study was to compare the clinical outcomes of the two therapies in a US community oncology setting. Methods: A retrospective study was conducted using US Oncology’s (USON) iKnowMed electronic health record (EHR) database, supplemented with chart review. Patient eligibility criteria included: ≥ 18 years of age at first diagnosis of aRCC, treated with pazopanib or sunitinib as the 1st LOT between 11/1/2009 – 8/31/2012 in the USON with ≥ 2 office visits. A propensity score (PS) matching was performed to match patients receiving pazopanib to sunitinib. Clinical outcomes including progression free survival (PFS), overall survival (OS) and adverse events (AEs) were compared. Results: A total of 177 patients on pazopanib and 739 patients on sunitinib were identified from the EHR database. After PS matching, 153 pts were included in pazopanib and sunitinib cohort respectively. The mean age, gender distribution, and the Heng disease risk groups were similar between the two cohorts (p>0.05). No significant difference in PFS was observed with pazopanib (median: 9.3 [95%CI, 7.0 to 11.8] months) compared to sunitinib (median: 8.3 [95%CI, 6.4 to 10.9] months, p = 0.43). Similarly, no significant difference was observed in OS for pazopanib (median: 22.3 [95% CI, 16.2 to 31.7] months) compared to sunitinib (median: 26.3 [95% CI, 16.4 to 38.2, p = 0.76] months). AEs (any grade) including diarrhea, hypertension, nausea, vomiting, fatigue were significantly lower in sunitinib (p<0.05) while anorexia was lower in pazopanib (p<0.05). Conclusions: Consistent with the results of COMPARZ, no significant difference was observed in PFS and OS among aRCC patients treated with pazopanib or sunitinib as the 1st LOT in the real world. AEs seemed to be less common with sunitinib, and this may be partially attributed to the limitation of retrospective data.