Predictors of long-term responders in patients treated with pazopanib for advanced renal cell carcinoma (aRCC).

524Background: The objective of this study was to characterize the long term responders to pazopanib (PAZ) treatment in aRCC patients treated in a real-world community oncology setting. Methods: This retrospective study used US Oncology’s (USON) iKnowMed electronic health record database (Nov 2009 – Oct 2014), supplemented with chart review. Eligible patients: Age ≥ 18 at first diagnosis of aRCC, treated with PAZ as first-line between 11/1/2009 – 8/31/2012, and had at least 2 office visits during the follow-up period. Patients were excluded if they were enrolled in a clinical trial and diagnosed or treated for other primary cancers during the study period. Long-term responders were defined as patients with progression free survival (PFS) ≥18 months. Predictors of long-term responders to PAZ were assessed using multivariate logistic regression analysis. Results: A total of 153 PAZ patients were included of which, 33 patients (22%) were identified as long-term responders. The median PFS in long-term respond...