Pharmacotherapy options in advanced renal cell carcinoma: what role for pazopanib?

Over the last 6 years, the treatment of metastatic renal cell carcinoma (mRCC) has undergone dramatic changes. A better understanding of the pathogenesis and tumor biology of sporadic renal cell carcinoma has led to the approval of 6 drug regimens: 3 oral multi-targeted tyrosine-kinase inhibitors (sorafenib, sunitinib, and pazopanib), 2 inhibitors of the mammalian target of rapamycin (temsirolimus and everolimus), and 1 monoclonal antibody against the vascular endothelial growth factor (bevacizumab). Pazopanib, a multi-targeted tyrosine kinase inhibitor that targets VEGFR-1, -2, and-3; PDGFR-α and PDGFR-β, and c-Kit, was approved for the treatment of mRCC in October 2009, several years after the other drugs in its class. The efficacy and safety of pazopanib in Phase I, II, and III trials will be examined and its role in mRCC treatment will be described. Future studies that may clarify pazopanib’s role in mRCC will be discussed. Based on pazopanib’s demonstrated efficacy in treatment-naïve and cytokine-refractory patients, along with a seemingly favorable toxicity profile compared with other multi-targeted tyrosine-kinase inhibitors, pazopanib may have a unique niche in the armamentarium of treatment options for mRCC. Results from ongoing studies are awaited to confirm pazopanib’s favorable efficacy-toxicity ratio, especially in comparison with the previous first-line standard-of-care, sunitinib.

Pazopanib for the treatment of patients with advanced renal cell carcinoma

Dramatic advances in the care of patients with advanced renal cell carcinoma have occurred over the last ten years, including insights into the molecular pathogenesis of this disease, that have now been translated into paradigm-changing therapeutic strategies. Elucidating the importance of signaling cascades related to angiogenesis is notable among these achievements. Pazopanib is a novel small molecule tyrosine kinase inhibitor that targets VEGFR-1, -2, and -3; PDGFR-α, PDGFR-β; and c-kit tyrosine kinases. This agent exhibits a distinct pharmacokinetic profile as well as toxicity profile compared to other agents in the class of VEGF signaling pathway inhibitors. This review will discuss the scientific rationale for the development of pazopanib, as well as preclinical and clinical trials that led to approval of pazopanib for patients with advanced renal cell carcinoma. The most recent information, including data from 2010 national meeting of the American Society of Clinical Oncology, and the design of ongoing Phase III trials, will be discussed. Finally, an algorithm utilizing Level I evidence for the treatment of patients with this disease will be proposed.