Sunitinib Scheduling In Metastatic Renal Cell Cancer: A Single-Center Experience.

554 Background: Sunitinib is a receptor tyrosine kinase inhibitor that has proven activity as first line treatment for metastatic renal cell carcinoma (mRCC). The recommended dose is 50mg once daily in a 4 week on 2 week off schedule. However this regimen has a significant side effect profile and alternative schedules have been used to minimize dose reductions and maintain dose intensity. We sought to identify the incidence of dose modifications and assess toxicity in patients treated with two sunitinib schedules in a National Cancer Center. Methods: Patients with mRCC who had sunitinib as first line treatment were identified retrospectively and patient data reviewed. Two patient groups were identified: those who received sunitinib 50mg day 1-28 in 6 week cycles (cohort 1) and those who received sunitinib 50mg day 1-14 in 3 week cycles (cohort 2). Primary end point was incidence of dose modification. Secondary end points included incidence of common sunitinib-related side effects. Known prognostic variabl...