FDA Approves New Kidney Cancer Drug

The U.S. Food and Drug Administration on Wednesday gave its approval to a new drug called Torisel (temsirolimus) for treating renal cell carcinoma, a type of advanced kidney cancer.

The approval of the drug, an enzyme inhibitor made by Wyeth Pharmaceuticals, was based on a study that showed use of the drug prolonged survival of patients with renal cell carcinoma. The study results were first presented last June at the American Society of Clinical Oncology annual meeting in Atlanta. And they were just published in the May 31 issue of the
New England Journal of Medicine.

"We have made significant advances in the battle against kidney cancer," Dr. Steven Galson, director of the FDA's Center for Drug Evaluation and Research, said in a prepared statement. "Torisel is the third drug approved for this indication in the past 18 months, and one that shows an increased time in survival for some patients."
The approval of Torisel follows the December 2005 approval of Nexavar (sorafenib), which was based on a delay in progression of disease. In January 2006, Sutent (sunitinib) received accelerated approval based on durable response rate, or tumor size reduction, and was later demonstrated to delay tumor progression.

The phase III, randomized clinical study of Torisel included 626 patients who received one of three treatments: temsirolimus; an older drug called interferon; or both drugs together. Patients who received temsirolimus alone survived longer (a median of 10.9 months) than those who received interferon/temsirolimus (8.4 months), or interferon alone (7.3 months).

"This is the first study to show that a new drug can improve overall survival for patients with metastatic renal cell cancer," said Dr. Gary R. Hudes, the lead author of the NEJM study, in a prepared statement.

Hudes, director of the Genitourinary Malignancies Program at Fox Chase Cancer Center in Philadelphia, said patients who received the combination treatment received a lower dose of temsirolimus than those who received temsirolimus alone. This could explain why those who received the combination treatment did not survive as long as those who received temsirolimus alone.

Many patients with kidney cancer are cured by surgery to remove the tumor. However, about 35 percent of patients will experience cancer recurrence or their cancer will spread to other parts of the body.

"For these patients, the goal of treatment is to prevent further spread and growth of the cancer, and ideally, to reduce that amount of cancer," Hudes said. "Until recently, physicians lacked effective drugs to control the disease."

He noted that this study found that temsirolimus provided modest improvement in survival for patients with the most advanced tumors.

"It would be reasonable to hypothesize that temsirolimus could provide greater benefit to patients with less extensive metastatic disease. Only a randomized clinical trial will give us that definitive knowledge," Hudes said.