The U.S. Food and Drug Administration today approved pazopanib (Votrient?, GW786034; GlaxoSmithKline), the sixth drug to be approved for kidney cancer since 2005.Pazopanib, is an oral medication that selectively inhibits vascular endothelial growth factor receptors (VEGFR)-1, -2 and -3, c-kit and platelet derived growth factor receptor (PDGF-R), which may result in inhibition of angiogenesis, or growth of new blood vessels, in tumors in which these receptors are upregulated. All solid tumors need blood vessels to survive, and by stopping or slowing this process, Pazopanib and similar drugs medicines in this category, may halt the progression of tumor growth.Pazopanib is intended for people with advanced renal cell carcinoma (RCC), a type of kidney cancer in which the cancerous cells are found in the lining of very small tubes (tubules) in the kidney. This form of cancer is common type of kidney cancer and accounts for approximately nine out of ten cases. In 2009, approximately 49,000 people were diagnosed with renal cell carcinoma and 11,000 people died from the disease.?The last five years have seen dramatic improvements in treatment options for patients with kidney cancer. Before 2005, the options available offered only limited effectiveness,? said Richard Pazdur, M.D., director, Office of Oncology Drug Products in the FDA?s Center for Drug Evaluation and Research.The five other drugs approved for kidney cancer and their approval dates are: sorafenib (December 2005), sunitinib (January 2006), temsirolimus (May 2007), everolimus (March 2009), and bevacizumab (July 2009).The safety and effectiveness of pazopanib was evaluated in a 435-patient phase III study that examined a patient?s progression-free survival (PFS) ? the length of time, following enrollment in the study, before the tumor began growing again or before the patient died. Progression-free survival averaged 9.2 months for patients receiving pazopanib compared to 4.2 months for patients who did not receive the drug.Patients were randomly assigned on a 2-to-1 basis to receive either pazopanib or placebo. Pazopanib reduced the risk of disease progression or death by 54% (hazard ratio = 0.46 with 95% confidence interval 0.34 to 0.62; P<0.0000001). The overall response rate in the pazopanib arm for the overall study population was 30% with duration of response of 59 weeks.When specific patient groups were evaluated, those with no prior drug treatment experienced 11.1 months of median PFS with pazopanib versus 2.8 months with placebo. Patients who had previously received cytokine-based treatment showed 7.4 months of median PFS with pazopanib versus 4.2 months with placebo. These results were featured in an oral presentation at the annual American Society for Clinical Oncology (ASCO) meeting in Orlando, Florida.Adverse reactions included diarrhea, high blood pressure, hair color changes, nausea, loss of appetite, vomiting, fatigue, weakness, abdominal pain and headache. Pazopanib can also cause severe and fatal liver toxicity. Health care professionals should order blood tests to monitor liver function before and during treatment with the drug. Since pazopanib can harm a fetus, it should not be used during pregnancy.?The study shows that pazopanib significantly improved PFS for patients regardless of whether or not they had prior therapy. While there have been many treatment advances for patients with advanced kidney cancer, there is still a need for medicines that are effective and well-tolerated,?said Dr. Cora N. Sternberg, Department of Medical Oncology, San Camillo and ForlaniniHospitals, Rome, Italy. ?Additionally, patients did not experience a significant decline in health-related quality of life with no significant differences between pazopanib and placebo.?The drug has also been associated with heart rhythm irregularities. Patients receiving pazopanib should be monitored with periodic electrocardiograms, which measure heart rhythm, and blood tests to monitor electrolytes since an electrolyte imbalance can lead to an irregular heart rhythm.Pazopanib has a broad clinical program across multiple tumor types. Programs currently underway in advanced RCC include a head-to-head comparison trial with sunitinib in patients with no prior drug treatment. More than 2,000 patients have been treated to date in clinical trials.Commenting on the approval of pazopanib in RCC, Paolo Paoletti, Senior Vice President, R&D Oncology Unit noted: ?We?re extremely pleased to see the progress in developing pazopanib for advanced kidney cancer, but this represents just one type of cancer in need of new treatments. Our global studies using pazopanib are designed to find new ways to use a proven mechanism to fight a diverse group of cancers. This further demonstrates our efforts to discover new medicines that provide tangible clinical benefits for patients.?
Pazopanib – A New Treatment for Advanced Kidney Cancer