Alternative dosing schedules for sunitinib as a treatment of patients with metastatic renal cell carcinoma.

Sunitinib malate (Sutent; Pfizer, Inc., New York, NY) is an oral multitargeted tyrosine kinase inhibitor that inhibits VEGF receptors (VEGFR-1, VEGFR-2, and VEGFR-3) among a family of kinase targets and have a central role in first-line treatment of metastatic renal cell carcinoma (mRCC). The approved schedule for sunitinib is 50mg/day oid in the so called "4 weeks on and two weeks off" (4/2 schedule). Since treatment with sunitinib can be maintained for years, adequate treatment of adverse events (AEs) and care for quality of life is essential. For this reason, several alternative schedules have been proposed in order to personalize sunitinib administration and reduce related toxicity. This review discusses the efficacy and tolerability of alternative regimens to the standard 4/2 schedule that have been investigated in RCC patients including schedule of 50mg/day 2-weeks on/1-week off, continuous schedule of 37.5mg daily and the "Stop and Go strategy".