Tuesday, June 05, 2007

Revolutionary drugs fight cancer's basic mechanisms

Therapies that target the basic mechanisms of cancer have become the weapons of choice in the fight against the deadly disease, researchers said at a major doctors' conference in the United States.
"Molecular targeted therapies that were developed a few years ago are being expanded dramatically in scope," said Robert Ozols of Philadelphia's Fox Chase Cancer Center.
He was speaking at the 43rd annual conference of the American Society of Clinical Oncology (ASCO) under way here until Tuesday with 25,000 specialists in attendance.
Some of the smart drugs seen here can attack the basic functions of a cancer, preventing its cells from multiplying.
Using biotechnology, researchers discovered channels by which cancer cells link to one another and were able to find treatments to block them.
Other treatments refined in recent years can stop tumors from developing blood vessels to nourish themselves. Such treatments are revolutionizing cancer treatment.
The first drug of this kind is Avastin, marketed in Europe by the Swiss company Roche and in the United States by Genentech.
It has already proven effective at prolonging life in tests on patients with advanced colon and lung cancer. A study published here this weekend showed that it also doubled the life-span of those with serious tumors of the kidney.
Two other drugs were recently authorized for use against serious or treatment-resistant kidney cancer: Nexavar from the German company Bayer and Sutent from the US firm Pfizer, a drug that neutralizes genetic receptors that cause tumors to grow.
Previously these two drugs had been used for stomach and colon cancer.
Nexavar also prolonged by 44 percent the lives of patients with advanced liver cancer, according to clinical trial results unveiled here.
Joseph Llovet, author of the Nexavar study, said it was the first effective systematic treatment for liver cancer, the third most deadly cancer in the world.
The drug works by inducing cancer cells to self-destruct and preventing them from growing blood vessels.
The French drug group Sanofi-Aventis meanwhile presented results of a test in which the new medicine Aflibercept halted progression of an ovarian cancer case that was not responding to chemotherapy.
"We are witnessing a revolution in the understanding of human cancer," said Julie Gralow, associate professor of oncology at the University of Washington, Seattle.
A combining of genetic science and biotechnology is going to expand treatments tailored to the makeup of individual patients' genes and of their cancers, she said.
"The personalization of cancer medicine represents a tremendous potential for prevention and early detection of cancer and improvement of the effectiveness and tolerability of therapy."
"These are incremental advances, but they're important," said Len Lichtenfeld, a doctor of the American Cancer Society.
"We've come to a time when these advances are becoming routine, and that's a good thing."

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