Wyeth’s Torisel approved by FDA : New drug for Kidney cancer

The US Food and Drug Administration (FDA) on Wednesday approved Torisel (temsirolimus), a new type of drug for the treatment of an advanced form of kidney cancer called renal cell carcinoma, manufactured by Wyeth Pharmaceuticals Inc.

This drug has been found to prolong the survival of advanced renal carcinoma patients by about 3 ½ months, according to a study led by Gary R. Hudes, M.D., director of the Genitourinary Malignancies Program at Fox Chase Cancer Center.

The study has been published in the New England Journal of Medicine.

A total of 626 patients with renal cell carcinoma (RCC) were enrolled in the study and were subjected to one of the following three treatments – the new drug Torisel, an older drug called interferon, or both the drugs together. The patients who received Torisel alone survived longer than those who received interferon, the usual or ‘standard’ treatment for this disease.

According to this study, the greatest increase in median survival was observed in patients receiving Torisel (49 percent) compared with patients treated with interferon only. Patients treated with Torisel and interferon combined had a 15 percent increase in median survival compared with interferon alone. The median survival for Torisel alone was 10.9 months compared with and 8.4 months for the Torisel and interferon, and 7.3 months for the interferon.

"This is the first study to show that a new drug can improve overall survival for patients with metastatic renal cell cancer," said Hudes.

Renal Cell Carcinoma is the most common type of kidney cancer, accounting for about 90% of all adult kidney cancer cases diagnosed in the U.S. Many patients with kidney cancer opt for a surgery to remove the tumor.
However, about 35% of them experience either a recurrence of the tumor or its spread to other organs.

“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."

The drug Torisel is basically an enzyme inhibitor, a protein that regulates cell production, growth and survival. Temsirolimus blocks the function of the mammalian target of rapamycin (mTOR), a key protein within cells regulating cell proliferation, growth and survival. It has also been found to block angiogenesis, the process to create a blood supply to tumors in order to maintain their growth.

This is the third drug for kidney cancer to be approved by FDA since late 2005, the earlier two being Bayer’s Nexavar, or sorafenib and Pfizer Inc.'s Sutent, or sunitinib.

Common side effects of Torisel include rash, fatigue, mouth sores, nausea, edema and a loss of appetite. Common laboratory abnormalities associated with the drug are high blood sugar, elevated blood lipids and tryglycerides, low RBC, WBC and platelet counts.

Also, this study focused on patients with the most advanced tumors. According to Hudes, Torisel can be expected to provide greater benefits to patients with less extensive metastatic disease.

Wyeth, in a statement, said its drug would be available for patients in July.