Sunitinib: a newly approved small-molecule inhibitor of angiogenesis.

The advent of targeted therapies has allowed treatment to be directed at signaling pathways integral to tumor growth and survival. Sunitinib (SU11248, sunitinib malate; Pfizer Inc., New York, NY, USA) is a novel oral small-molecule multitargeted receptor tyrosine kinase inhibitor that has demonstrated direct antitumor activity and antiangiogenic action. It targets the vascular endothelial growth factor receptor (VEGFR), platelet derived growth factor receptor (PDGFR), stem-cell factor receptor and Fms-like tyrosine kinase receptor 3 receptor tyrosine-kinases. In January 2006, sunitinib malate was granted approval by the U.S. Food and Drug Administration for the treatment of gastrointestinal stromal tumor after disease progression on, or intolerance to, imatinib mesylate, as well as for the treatment of metastatic renal cell cancer. This review will discuss the development of sunitinib, particularly in acute myeloid leukemia, imatinib-resistant gastrointestinal stromal tumors and renal cell cancer. The review will also discuss ongoing trials with sunitinib in other malignancies such as neuroendocrine tumors and breast cancer, as well as its potential future development in combination therapy with other agents and in other malignancies.