Dosing schedules and outcomes in patients with first-line sunitinib for advanced renal cell carcinoma

Background: The objective of this study was to determine whether sunitinib alternative schedules (ASs) could prolong survival of patients with advanced renal cell carcinoma (RCC) compared to the traditional 4-weeks-on/2-weeks-off schedule (TS). Patients and methods: Between August 2008 and December 2014, 58 patients with advanced RCC were treated with sunitinib. We retrospectively reviewed the records of the patients who received first-line sunitinib. The progression-free survival (PFS), overall survival (OS), relative dose intensity (RDI) and toxicity in the AS and TS groups were compared. Results: A total of 38 patients were included in analysis. ASs at treatment discontinuation or baseline were carried out for 22 patients who started to receive sunitinib beginning in December 2012. In these patients, sunitinib was administered with a 2-weeks-on/1-week-off, 2-weeks-on/2-weeks-off or 2-weeks-on/3-weeks-off schedule according to the adverse events (AEs) and clinical characteristics of each patient. The median PFS was 5.0 months (95% CI: 2.4-6.7) for TS compared to 11.8 months (95% CI: 6.2-17.5) for AS (p = 0.0016). The median OS was 17 months (95% CI: 10-25) for TS compared to 57 months (95% CI: not estimable) for AS (p = 0.0017). There was no difference in the RDI between the TS and AS groups (70% versus 78%). The incidence of Grade ≥3 thrombocytopenia in the AS group was smaller than that in the TS group (44% versus 27%). Conclusions: Treatment with sunitinib on an AS may provide a better outcome than that on the TS. Prospective, randomised trials should be conducted to confirm this speculation.