AKA STI571, Glivec is a drug which targets specific molecules to treat chronic myeloid leukemia, a rare form of leukemia.  By targeting specific molecules the drug is able to attack cancerous cells, largely without affecting normal cells throughout the body.  This is an incredible improvement over the way traditional chemo-treatment works.  Researchers hope to design similar drugs targeting other forms of cancer which affect far more people.
"This is as important as it gets.  A cancer-specific target, a drug specifically designed for the target, the most effective agent ever," says Paul A. Bunn Jr., president-elect of the American Society of Clinical Oncology.  "Read my lips, this is real, not mice."
Glivec was designed by Dr. Brian Druker, director of the Leukemia Program at the Oregon Health Sciences University in Portland, in conjunction with Novartis Pharmaceuticals.1
Glivec is expected to be available to patients in the U.S. within months.  The treatment has also been shown effective against gastrointestinal stromal tumor, a rare GI cancer.  Apparently those tumors have molecules similar enough to what STI571 attacks.  Tumors have been shrunk with fewer than 3% of the patients suffering side effects.  It may be too soon to know how effective these treatments are in the long-run but there is hope this could lead to cures for cancers.
Glivec (STI571) is the first of a new class of antiproliferative agents called signal transduction inhibitors, which interfere with the pathways that signal the growth of tumor cells.  Glivec (STI571) is targeted to the specific biochemical abnormality found predominantly in a form of leukemia called chronic myeloid leukemia (CML).  Glivec (STI571) kills the abnormal cells while having little effect on normal cell growth.  Laboratory studies have shown that Glivec also inhibits an enzyme called C-Kit which is present in a relatively rare form of cancer called GIST (Gastro Intestinal Stromal Tumor).  There are some small trials being conducted on GIST tumors in the U. S. A. with plans to expand those trials to other countries.  It is too early to reach any valid scientific conclusions with GIST, however, early data looks very promising.2
A summary of studies (April 2001) shows that 95% of the CML patients treated were in remission.  White blood counts are elevated in CML patients, in one study 30 of 31 patients had white blood cell counts return to normal after a month of daily doses of STI571.  The FDA in the U.S. has agreed to accelerate approval of the drug, making it available more quickly to those who would benefit.3
In the United States, Glivec is known generically as imatinib mesylate.  Outside of the United States it is known generically as imatinib.4
The release on the CMLSupport.com site includes a warning that future results are not guaranteed.  Also, some reports show less impressive numbers, but those reports are older or clinical trials testing STI571 on other types of cancer.
1. New Cancer Treatment: Doctors Excited by Promise of Drugs Targeted at Specific Molecules
-  ABCNews.com  -  April 4th
URL = http://abcnews.go.com/sections/living/DrJohnson/010404DrJohnson_Cancer.html
2. The Unofficial Glivec (STI571) Site
URL = http://www.newcmldrug.com/
3. STI571 Cancer Cure?  Latest STI571 Headlines
URL = http://www.globalchange.com/sti571.htm
4. FDA Grants Priority Review for Glivec (STI571)
URL = http://www.cmlsupport.com/cmlnewsglivecapproval0401.htm