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News
Tuesday December 5 6:35 AM ET
Leukemia Drug Generates Excitement
By COLLEEN VALLES, Associated Press Writer
SAN FRANCISCO (AP) - A leukemia drug that brought cancer into remission in most patients in clinical trials is generating excitement among cancer specialists and patients as a gentler, more effective treatment that may mean cancer researchers are on the right track.
``This drug is a major breakthrough,'' said Dr. Hagop Kantarjian, who oversees trials of the drug at the MD Anderson Cancer Center in Houston.
In manufacturer-financed clinical trials, more than 90 percent of patients in the first phase of chronic myeloid leukemia saw their cancer go into remission within the first six months of taking the pill, according to trial findings presented Monday at a meeting of the American Society of Hematology.
A study of patients in the second phase of the disease showed more than 90 percent of those patients responded positively to the treatment, and in 63 percent, the cancer went into remission. The trials involved 530 first-phase and 230 second-phase patients.
The early success has propelled researchers to test the Novartis AG-made drug STI-571, or Glivec, on almost 3,000 patients around the world; CML affects about 10,000 adults each year.
Anyone diagnosed with leukemia should make every effort to get the new pill, said Edward Benz, president of the Dana-Farber Cancer Institute at Harvard Medical School (news - web sites), who was not involved in the research.
``This is not a miracle drug,'' he said, but it is a model for future cancer study because it targets the cause of the disease without damaging other cells.
CML, caused by an abnormal protein that is the product of an abnormal chromosome, leads to a huge increase in the number of white blood cells in the body, which can interfere with the functioning of other organs.
Glivec blocks a signal that protein sends out and effectively prevents the abnormal growth and production of other cancerous cells.
``The whole of cancer research has been to identify the differences between cancer cells and normal cells. That's been the goal of cancer research and here it is,'' said Brian Druker, an Oregon Health Sciences University researcher who was the drug's principal developer. ``I view it as a new era of cancer therapeutics. It's the most effective treatment we know of for CML.''
Researchers chose CML because they knew about the abnormal chromosome and its abnormal protein. They are hoping to transfer the model - targeting a specific abnormality with minimal effect on healthy tissue - to other cancers, but first they must isolate those cancers' causes.
Currently, bone marrow transplants are the only proven way of curing leukemia, but the transplants carry a mortality rate of up to 40 percent and are only successful in 55 to 65 percent of cases. Other drugs are used to maintain the health of leukemia patients, but don't decrease the number of white blood cells or help make the blood normal again.
The common treatment for CML is interferon, which can extend a leukemia patient's life by up to two years but can have side effects that cause about 20 percent of patients to stop using it.
Glivec has been studied on humans for only about two years, so how long it will prolong a patient's life is not yet known. But it has had few side effects, and only about 2 percent of patients stopped using it because of those side effects.
The drug is expected to hit the market in June, and clinical trials will continue, studying such things as the drug's long-term effects.
In the meantime, patients who hope to receive the treatment have to join a clinical trial. Those in the first phase of the disease are put on a waiting list, while patients in more advanced stages are added to clinical trials, Druker said.
Carol Stuckey, a 50-year-old mother of two from West Linn, Ore., involved in the clinical trials, was diagnosed with CML seven years ago and was close to being in the final phase of the disease, when a patient only has months to live.
She has been on STI-571 since December 1999, and said the treatment has helped her lead a normal life. She said that she has sometimes had leg cramps or puffy eyes since starting to take Glivec, but that those are minimal side effects compared to the lack of energy she was experiencing.
``The main thing is that I got my life back,'' Stuckey said. ``I have energy again. Just prior to taking the medication, I was totally drained. Within two weeks of taking STI, I had wonderful energy. I went Christmas shopping.''
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'Fusion Gene' Kills Cancer Cells
Reuters
12:55 p.m. Aug. 25, 2000 PDT
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Gene therapy has taken another step forward with the announcement that a "fusion gene" --called p27/p16-- appears able to kill many types of cancer.
The finding "represents a powerful new therapeutic agent for cancer gene therapy," wrote James G. McArthur and his colleagues at Cell Genesys and at GPC Biotech in the August issue of Molecular Therapy.
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7-4-00
There are many areas of current active intense research aimed at addressing cancer and other illnesses. A major endeavor is the Human Genome Project (HGP), the national coordinated effort to characterize all human genetic material contained in human cells. The HGP's ultimate goal is to discover all the more than 80,000 human genes and render them accessible for further biological study.
Some of these genes have already been implicated in tumor growth. Oncogenes are genes in the cell that, once activated, help drive the cell's division in an uncontrolled manner. Similarly, there are some known tumor suppressor genes which are normally active in a cell to prevent uncontrolled growth, but which become defective or are "turned off" in some cancer cells.
While a number of these genes have been identified, however, only a small number are actually understood in detail. The sheer number of genes, gene codes and DNA subunits makes the study of this problem daunting.
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