Health and Human Services Secretary Tommy Thompson announced the government's green light for Gleevec, a breakthrough drug that effectively fights chronic myeloid leukemia (CML). Some researchers even call Gleevec a cure for the disease, which strikes an estimated 4,400 Americans a year, eventually killing half its victims.
Studies have shown that Gleevec, an oral drug, may also be useful in treating other forms of blood cancer as well as certain solid tumors. The drug is made by Novartis Pharmaceuticals Corp. of East Hanover, N.J."I think Gleevec is the most important breakthrough in CML. It is going to change dramatically the life expectancy of these patients and the way we treat them, and it may also have implications in the treatment of other cancers," says Dr. Hagop Kantarjian, chairman of the leukemia department at the M. D. Anderson Cancer Center in Houston.
Kantarjian, who helped lead studies of the drug in cancer patients, says Gleevec may cure CML in as many as half the people with the disease without forcing them to resort to bone marrow transplants.
The company sought FDA approval only for treating CML, but researchers say that the drug can be prescribed "off-label" for the other cancers. The agency gave Gleevec a priority review in March.
"After that, there's the world," says Dr. George Demetri, co-director of the sarcoma program at the Dana-Farber Cancer Institute in Boston. "The exciting thing about this drug is that it's not just leukemia. This is a paradigm of an entire new way of treating cancer."
Gleevec is a small molecule that deactivates BCR-ABL along with similar signaling proteins. Conventional leukemia therapy, like the drug interferon alfa, kills abnormal marrow cells, but it also destroys healthy ones and is therefore extremely difficult to tolerate.
Gleevec, on the other hand, selectively targets BCR-ABL, which is produced only by cancerous cells. As a result, experts say its side effects, which include nausea, vomiting, swelling and diarrhea, are generally milder than other treatments.
A research team at Oregon Health Sciences University, led by cancer expert Dr. Brian Druker, gave varying doses of the drug to 54 CML patients who'd already failed to improve on interferon alfa.
At the optimal dose of 300 milligrams a day, abnormal cells disappeared from the blood of all but one of the patients. The number of cancerous marrow cells in more than half the patients dropped significantly, and seven went into complete remission, the study found.
In a second trial, Druker's team gave Gleevec to patients with more advanced CML, as well as patients with acute lymphoblastic leukemia (ALL) in which BCR-ABL also was present. One in five ALL cases involves the same chromosome that goes haywire in people with CML.
Other recent research also suggest that some gastrointestinal stromal tumors (GISTs) express a relative of BCR-ABL called c-kit, which responds well to Gleevec. And in a third study, researchers in Finland and the United States report the drug has been keeping a woman with an advanced GIST alive for more than a year.
The findings were released last month in the New England Journal of Medicine.
What To Do
Talk to your doctor about this drug if you suffer from CML or even another blood cancer. It should be available by the end of the month. Approval for one use allows doctors to prescribe it for other suitable uses. The drug doesn't come without some side effects, including nausea, vomiting, fluid retention, heartburn, and skin rashes.
To learn more about the development of Gleevec, read this HealthScout story.
Or read other HealthScout articles about leukemia.