Researchers celebrate breakthrough in cancer treatment
biz.yahoo.com
By Andrea Orr
SAN FRANCISCO, Jan 15 (Reuters) - Years of research into safer and more potent cancer treatments may have begun to pay off with advances that use the body's own defenses.
Biotechnology companies gathering in San Diego this week to discuss progress in bringing new drugs to market say some of their most promising research involves monoclonal antibodies, which are natural immune system chemicals that have been altered for use as cancer drugs.
Because they originate in the human body, they are far less toxic than chemotherapy and radiation, and several companies are steaming ahead to develop therapies based on them.
Among some of the recent developments are the approval late last year by the Food and Drug Administration of Rituxan, the first monoclonal antibody for cancer. Rituxan, which targets non-Hodgkin's lymphoma, was developed by IDEC Pharmaceuticals (Nasdaq:IDPH - news) and Genentech Inc(NYSE:GNE - news).
Coulter Pharmaceutical Inc. also has developed a similar drug for non-Hodgkin's lymphoma that shrinks tumors and in some cases puts patients in whom other treatments have failed into complete remission -- meaning there is no sign of cancer in their bodies.
At the Hambrecht and Quist Healthcare Conference here, Coulter President Michael Bigham said the company would seek FDA approval of Bexxar this year and predicted it would become the ''gold standard'' of treatment in non-Hodgkin's lymphoma.
Genentech has applied this science to other cancers and plans to file for FDA approval of a new breast cancer drug in a few months. It is also working on a related drug designed to starve cancer tumors by cutting off their blood supply.
Similar research is underway at a handful of other biotech companies, including ImClone Systems Inc. (Nasdaq:IMCL - news), which is working on monoclonal antibodies for breast, head and neck, lung and prostate cancers.
''This is a genuine advance,'' Dr. Mark Cohen, Genentech's associate director of molecular oncology, said of this building body of research.
''Is it a cure for cancer? I don't think so. But the hope is that we will eventually be able to cure some patients who wouldn't otherwise be cured.''
Monoclonal antibodies are designed to fight cancer the way the body's natural immune system fights other diseases. Years ago, researchers found they could make antibodies to fight cancer by injecting foreign proteins into mice and then harvesting the agents the mice secreted in defense.
The problem was that these antibodies did not make effective treatments for humans: since they came from mice, the human body would reject them.
But over the past decade, scientists at IDEC and Genentech found a way around that problem. They isolated the active ingredient in the mouse antibody and attached it to a human antibody so that it would be better tolerated.
That breakthrough eventually led to the development of Rituxan, a drug that selectively targets cancerous cells while avoiding most of the surrounding healthy tissue. In theory, this means the treatment is less toxic than traditional radiation or chemotherapies.
In practice, however, this is still not the case. Doctors are recommending Rituxan be used in combination with other drugs like chemotherapy to give the patient the best possible chance of recovery.
''Drug combinations are the name of the game in cancer treatment,'' said Genentech's Cohen. ''There are very few examples of any cancer drugs being effective when used by themselves.''
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