Glaxo Kidney Cancer Drug Has Liver Risk, FDA Says

GlaxoSmithKline Plc’s experimental treatment for advanced kidney cancer causes side effects, according to U.S. regulators weighing new competition to Pfizer Inc.’s Sutent.

Glaxo’s pazopanib may be “associated with a significant risk” of severe liver injury in patients with advanced renal cell carcinoma, the most-common form of kidney cancer, Food and Drug Administration staff said in a review posted today on the agency’s Web site. Outside advisers to the FDA will meet Oct. 5 in Gaithersburg, Maryland, to review the findings and recommend whether the product should be approved.

Surgery to remove the kidney was a common cancer treatment before the FDA approved Sutent and Nexavar, from Bayer AG and Onyx Pharmaceuticals Inc., almost four years ago. The pills, from the same family of medicines as pazopanib, slow progression of the disease by blocking enzymes that promote tumor growth.

“The FDA is concerned about the benefit-to-risk ratio of pazopanib in the intended population of patients,” the agency said in the documents. “This is particularly true in a setting in which there are other effective products approved for the treatment of advanced renal cell cancer.”

An estimated 57,760 new cases of kidney cancer will be diagnosed in the U.S. this year, and almost 13,000 people will die of the disease, according to the American Cancer Society. Many patients don’t know they have cancer until it has reached an advanced stage because small tumors can’t be felt and aren’t easily detected in an exam.

Benefits of Treatment

Once-daily pazopanib reduced the risk of tumor progression or death by an average of five months, or 54 percent, compared with a placebo pill, according to a study Glaxo submitted as part of its new drug application. The medicine didn’t show a statistically significant improvement in overall survival, according to the FDA review.

“We strongly believe in pazopanib as a valuable treatment for patients,” spokeswoman Claire Brough said in an interview. The overview of data it will present to a U.S. advisory committee “demonstrates the benefit of the drug.”

The company is testing pazopanib’s safety and effectiveness versus Sutent in a head-to-head study with results due within the next couple of years.

Five Drugs Approved

The FDA has approved five drugs for renal cell carcinoma since December 2005. Sutent was shown to increase progression-free survival by 25 weeks compared with placebo, according to the staff review.

Sutent and Nexavar had “no hepatic safety signals” when they were approved, though “recent literature reports show a few cases” of kidney failure and deaths in the past three to four years of marketing, regulators said, noting “this may be suggestive of a class effect.”

The agency is scheduled to decide on pazopanib by Oct. 19. The agency usually follows the recommendations of its panels, though it isn’t required to do so.

Glaxo has applied to sell the medicine under the brand name Votrient. Glaxo rose 5.5 pence to 1,235 pence as of 2:51 p.m. in London trading.

Sutent generated revenue of $847 million last year for New York-based Pfizer. Sutent is also approved for cancer of the digestive system.