Treatment patterns in metastatic renal cell carcinoma: a retrospective review of medical records from US community oncology practices

Background: Vascular endothelial growth factor (VEGF) inhibitors, including targeted therapy with tyrosine kinase inhibitors (TKIs) and the angiogenesis inhibitor bevacizumab, and mammalian target of rapamycin (mTOR) inhibitors are now the standard of care for metastatic renal cell carcinoma (mRCC). However, real-world treatment patterns are not well characterized. Objective: To describe treatment patterns during the first, second, and third lines of targeted therapies for mRCC among community oncologists in the US. Methods: Participating physicians recruited from a nationwide panel each identified up to 15 adult mRCC patients who initiated a second therapy after January 2010. Information extracted from medical records included types of targeted therapies, reasons for treatment choices, patterns of treatment discontinuation, and dose adjustments. Results: Thirty-six physicians contributed charts from 433 mRCC patients. Seventy-seven percent of patients received a VEGF inhibitor as first targeted therapy; 23% received an mTOR inhibitor. Among first-line VEGF users, second-line treatments were 66% mTOR and 34% VEGF inhibitors. Among first-line mTOR users, second-line treatments were 94% VEGF and 6% mTOR inhibitors. Sunitinib followed by everolimus was the most commonly used treatment sequence. Estimated median duration for second targeted therapy was 8.6 months, and median overall survival (OS) and progression-free survival (PFS) were 27.4 and 10.8 months, respectively. Efficacy, treatment guidelines and mechanism of action were the most important considerations for treatment choice. Limitations: Limitations include no adjustment for baseline characteristics, possible difference between physiciandefined progression and central review in the clinical trial setting, and limited data availability for axitinib during the study period. Conclusion: In this large retrospective chart review among community oncologists, VEGF-mTOR-VEGF was the most common treatment sequence for mRCC. The most common drugs were sunitinib in the first line and everolimus in the second line.