Sunitinib (marketed as Sutent, previously known as SU11248) is a small molecule receptor tyrosine kinase inhibitor that is used in the treatment of gastrointestinal stromal tumor (GIST) as well as renal cell carcinoma (RCC).

Sunitinib inhibits signaling through multiple tyrosine receptor kinases, including platelet-derived growth factor receptor and vascular endothelial growth factor receptor. Its efficacy in GIST is due to inhibition of the mutationally active c-kit kinase, including mutants that have become resistant to (imatinib) (Gleevec), another kit inhibitor.

Sunitinib is primarily being used in patients with GIST who have disease progression during prior imatinib treatment or those who did not tolerate imatinib. In one clinical trial of this patient population, the time to progression was significantly longer in the sunitinib arm than the placebo arm (27 v 6 weeks). Data on overall survival are not mature yet.

Notable side effects included diarrhea, hypertension, skin discoloration, mucositis, fatigue, and hypothyroidism. Neutropenia, thrombocytopenia, and decreases in left ventricular ejection fraction have also been seen with sunitinib.

Efficacy in renal cell carcinoma is probably through inhibition of vascular endothelial growth factor receptor. RCC is one of the most highly vascularized of tumors and is also being targeted by other angiogenesis inhibitors. These inhibitors in theory should have effficacy against many solid tumors, and sunitinib is currently in trials for breast, colon and lung cancers.

Sutinib was approved by the FDA for RCC and GIST on January 26, 2006.

Cancer treatments | Tyrosine kinase inhibitors