Angiogenesis inhibitor therapies for metastatic renal cell carcinoma: effectiveness, safety and treatment patterns in clinical practice-based on medical chart review

OBJECTIVE To assess the effectiveness, safety, and treatment patterns of anti-angiogenic agents in metastatic renal cell carcinoma (mRCC) in tertiary clinical practice settings. PATIENTS AND METHODS We retrospectively reviewed the medical records in two tertiary oncology centres in the USA for all patients treated while off clinical trials from April 2003 to June 2008 who met the entry criteria and received one or more prescriptions for sunitinib or sorafenib, or one or more intravenous administrations of bevacizumab (off-label) as first-line anti-angiogenic treatment. The objective response rate (ORR) reviewed by independent physicians, adverse events (AEs), and treatment modifications were assessed. RESULTS Among 144 patients receiving sunitinib (57), sorafenib (62) and bevacizumab (25), the median treatment duration was 10.5, 8.1 and 7.9 months, and the ORR was 37%, 9% and 13%, respectively. The ORR was lower for patients with metastases to bone, brain, lungs or lymph nodes. Common AEs (all grades) for sunitinib were fatigue (53%), diarrhoea (37%); for sorafenib, diarrhoea (50%), fatigue (40%); for bevacizumab, fatigue (40%), nausea (24%). In all, 34 (60%), 51 (82%) and 20 (80%) patients receiving sunitinib, sorafenib and bevacizumab, respectively, discontinued treatment; 10 (18%), 11 (18%) and four (16%) discontinued due to AEs; 21%, 40% and 12% had a dose interruption, and 30%, 35% and 0% had a dose reduction. CONCLUSIONS Currently available anti-angiogenic agents had considerable effectiveness in clinical practice. However, the response rates appeared to be low in certain subgroups, but sample sizes were small. Patients had significant rates of AEs, many of which led to treatment modifications. The findings from this retrospective study suggest that there is a need for better-tolerated therapies for mRCC.