Pazopanib: a promising new agent in the treatment of soft tissue sarcomas.

Pazopanib (GW786034) is a novel, small-molecule tyrosine kinase inhibitor. The primary mechanism of action of pazopanib can be described through its antiangiogenic properties via inhibition of the intracellular tyrosine kinase of VEGF receptor (VEGFR) and PDGF receptor (PDGFR). It is an orally available angiogenesis inhibitor that targets VEGFR-1, -2 and -3, PDGFR-α and -β, and c-kit. Pazopanib exhibits distinct pharmacokinetic and toxicity profiles compared with other agents in that class. Phase I studies defined the recommended monotherapy dose of pazopanib as 800 mg once daily. In 2009, it was approved in the USA for the treatment of advanced and metastatic renal cell carcinoma, and subsequently approved in other countries and demonstrated clinically and statistically significant activity in Phase II and III studies in advanced soft tissue sarcoma patients. This article focuses on its emerging role in the treatment of advanced soft tissue sarcomas.