New-Generation Drug OK’D to Treat Advanced Kidney Cancer
CHICAGO _ A new-generation cancer drug developed at the University of Chicago won government approval Tuesday for use in treating patients with advanced kidney cancer.
The U.S. Food and Drug Administration said the agent, Nexavar, is a significant step forward. The current standard treatment for kidney cancer _ immune therapy with interferon or interleukin-2 _ has only modest benefits and can be extremely toxic.
The new drug has few side effects, and some patients who started taking it more than two years ago are still doing well, researchers said Tuesday.
Kenneth Vajda, 52, of Naperville, Ill., was overjoyed when he heard the drug had been approved. He has been taking Nexavar for more than a year. “This is a breeze compared with interferon or interleukin,” Vajda said. “I have not missed a day’s work on this drug.”
Nexavar is one of a new generation of anti-cancer agents made possible by advances in molecular biology. These so-called targeted therapies attack specific features of the cancer cells and generally spare the body’s healthy cells. Conventional chemotherapy, by contrast, attacks all rapidly dividing cells, including those in the mouth and the stomach lining. As a result, chemo patients generally suffer severe side effects, such as nausea, vomiting and hair loss.
Vajda was diagnosed with kidney cancer in 1989. Although it responded to standard therapies, it always came back. In 2000 it spread to his lungs and pancreas.
In October, 2004, he got into a clinical trial of Nexavar at the University of Chicago.
“I’ve been on it ever since,” he said. “I take two pills in the morning and two in the evening. And I really have not had any bad side effects.
“I’m in pretty good shape,” he added. “I bought a bike in May, and within a month or two I was riding 11 miles a day.”
Dr. Mark Ratain, chief of clinical pharmacology at the University of Chicago, said the investigators who are conducting a large-scale trial of Nexavar have not yet done a final analysis to see whether patients on Nexavar live longer, “but the interim survival analysis is clearly promising.”
One problem confounding the calculations, he said, is that patients who were taking a placebo were allowed to “cross over” and receive Nexavar if they got worse on the dummy pills. Doctors couldn’t ethically withhold the experimental drug once it became clear it was working.
The drug, developed by Bayer and Onyx Pharmaceuticals, was originally designed to treat colon cancer, but it bombed on that disease. It was rescued from oblivion _ and ultimately found to work in a different group of patients _ thanks to an innovative study design.
Most intermediate trials test the effects of an experimental drug on patients with a particular illness, such as colon cancer, and look at how many patients see their tumors shrink. In the case of Nexavar, however, Ratain took a different approach.
Doctors enrolled patients with many different tumor types. After 12 weeks, those whose tumors shrank stayed on the drug. Those whose tumors grew were dropped from the trial. And those whose tumors were stable were randomly assigned to receive either Nexavar or a placebo for the next 12 weeks.
It soon became apparent that many patients with kidney cancer were responding.
The drug targets enzymes in tumor cells and the blood vessels that feed them. It appears to work by stopping cancerous cells from proliferating and also starving the tumor by shutting down its blood supply.
According to the American Cancer Society, 32,000 Americans a year are diagnosed with kidney cancer and about 12,000 die of it.
Nexavar is also being studied to see if it inhibits other types of cancer.
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(c) 2005, Chicago Tribune.
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