By ED SUSMAN
After five years of treatment nearly 90 percent of leukemia patients treated with Gleevec are still alive — an outcome barely conceivable before the drug was discovered.
The Gleevec story truly is a triumph of science over disease, Brian Druker, the lead investigator of the studies with the anti-cancer drug, told United Press International Wednesday.
Druker, professor of medicine at the Oregon Health and Sciences University Cancer Center in Portland, said, The results we have seen really are astounding. Before Gleevec (generically known as imatinib), patients with chronic myeloid leukemia had about a 50 percent to 60 percent chance of survival for five years and maybe 10 percent survival at eight years.
In a report to be published Thursday in the New England Journal of Medicine, Druker wrote that 95 percent of patients treated with Gleevec were virtually disease-free after five years. Some patients died from other causes over the time period, but death from leukemia has been rare.
Chronic myeloid leukemia was considered a universally fatal disease 30 years ago, said Len Lichtenfeld, deputy chief medical officer of the American Cancer Society in Atlanta. It was called chronic only because it killed people at a slower rate that the acute form of the disease, not because it was a long-term chronic illness such as heart disease or diabetes.
Lichtenfeld told UPI, Gleevec really has turned chronic myeloid leukemia into a chronic disease. We cannot really cure this disease, but we can now tell people that if they adhere to their medical prescription it is likely they will be alive and healthy 5, 10, 15 years later.
In fact, Druker said one impressive finding after five years of treatment is that the relapse rates are actually decreasing rather than accelerating as with previous treatments. Before Gleevec, treatment with interferon and anti-cancer drugs were able to control the disease for short periods before patients relapsed.
Lichtenfeld noted that even in cases where Gleevec fails to control the disease, new compounds have now been discovered that appear to be able to treat those patients who become resistant to Gleevec.
Acute myeloid leukemia is diagnosed in about 10,000 Americans a year, Druker said. What causes the disease — aside from major exposure to radiation (survivors of atomic bomb attacks in Hiroshima and Nagasaki are prone to the disease) — is unknown.
He said some form of accident in the body’s DNA causes fusion of genes. That abnormal gene is part of a molecular cascade that results in a deadly excess proliferation of blood cells.
Druker said he likens the development of Gleevec to fixing a broken thermostat. We identified that the thermostat was running hot. We took it apart and found out what the broken piece was (the fusion gene), and then we found something that could repair the gene (Gleevec).
Of the 553 patients who were originally treated with Gleevec in the clinical studies, at the end of five years 57 of those individuals had died. However, just 23 of those deaths were caused by or were related to chronic myeloid leukemia. The clinical trials with Gleevec, once known as STI571, were sponsored by Novartis.
Gleevec is the model of how we are fighting cancer now and in the near future, Lichtenfeld said. It is an outstanding accomplishment.
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