Researchers have developed the most effective treatment yet for patients suffering from chronic myeloid leukemia (CML), a cancer of the blood cells that strikes nearly 10,000 adults each year. According to clinical trial findings presented on Monday in San Francisco at the annual meeting of the American Society of Hematology, the Novartis AG-made drug, STI-571 (or Glivec), sent the cancer into remission in most patients. Although the oral drug has been in trials for only two years, investigators believe it may succeed in ridding the body of the disease long-term or even permanently. Currently the only proven cure for CML is bone marrow transplantationa high-risk procedure with a mortality rate of up to 40 percent. Other treatments aim to maintain the health of leukemia patients for as long as possible, but they don't normalize the blood and can have considerable side effects. Glivec, in contrast, has had few reported side effects because it targets the cause of the cancer, without harming other cells
CML patients have a chromosome defect that creates an abnormal protein known as Bcr-Abl, which in turn causes white blood cells to proliferate uncontrollably. Glivec apparently works by blocking the signal Bcr-Abl issues. In clinical trials financed by Novartis, patients in the first phase of CML gained the most benefit from Glivec: 90 percent of the 530 participants experienced remission of their cancer after only six months of treatment. But second-phase subjects still responded impressively: 90 percent of these patients, who numbered 230, also responded positively to the treatment, and remission occurred in 63 percent.
The new drug, which is expected to reach the market in June, may even serve as a model for developing drugs for other types of cancer. "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," Oregon Health Sciences University researcher Brian Druker, the drug's principal developer, said, according to an Associated Press report. "I view it as a new era of cancer therapeutics."