Pazopanib, a VEGF receptor tyrosine kinase inhibitor for cancer therapy.

Pazopanib, which is being developed by GlaxoSmithKline plc, is an oral, second-generation multi-targeted tyrosine kinase inhibitor that targets VEGFR, platelet-derived growth factor receptor and c-kit, key proteins responsible for tumor growth and survival. Pazopanib exhibited good potency against all of the human VEGFRs and closely related tyrosine receptor kinases in vitro, and demonstrated antitumor activity in several human tumor xenografts, including renal cell carcinoma (RCC), and breast and lung cancer. In phase I and II clinical trials, pazopanib was generally well tolerated with the main side effects being hypertension, fatigue or gastrointestinal disorders. Pazopanib alone caused a decrease in tumor size and stable disease in a significant number of patients, including those with RCC, NSCLC and gynecological tumors. The combination of pazopanib with lapatinib was effective in patients with breast cancer. At the time of publication, pazopanib monotherapy was being evaluated in phase III trials in patients with RCC and as combination therapy with lapatinib in patients with breast cancer. In addition, phase I and II trials were being conducted to assess pazopanib alone or in combination with a range of chemotherapeutics in patients with solid tumors or multiple myeloma.