Experimental Drug Works in Chronic Leukemia
April 4, 2000 (San Francisco) -- Doctors say an experimental drug that
showed extraordinary early success in controlling leukemia may also work in a
rare but lethal brain cancer, and in a form of lung cancer.
Known under its research name of STI571, the drug, taken by mouth, is
designed to interfere with a key substance in the body that is required for
development of chronic myelogenous leukemia (CML). CML is a blood disease that
strikes 4,500 people in the U.S. each year in which the body overproduces white
blood cells. About a third of the people are candidates for bone marrow
transplants, while the rest have to rely on the drug interferon. From time of
diagnosis, the average person will die within four to six years.
But for patients participating in the STI571 studies, their white blood
cells returned to normal levels if they were taking appropriate amounts of the
drug -- about four tablets once a day, according to lead researcher Brian
Druker, MD. Druker, associate professor of medicine at the Oregon Health
Sciences University in Portland, presented his findings at a meeting of cancer
"The patients are still taking the medication, about eight to 10 months
later, because if we look closely in their bone marrow, we can still see
evidence of the leukemia," Druker tells WebMD. The patients entered into
the study had been diagnosed with CML for an average of three and a half
Druker explained that STI571 is designed to halt the disease from
progressing. He said the pill also appears to be effective against a brain
cancer called glioblastoma, and for small cell lung cancer as well.
"We are really witnessing an enormous payoff of the Unites States
investment in cancer research," said William Hait, MD, director of the
Cancer Institute of New Jersey in New Brunswick. "It is uncommon to see
this kind of response in [the early stages of a] clinical trial. To see even a
25% response rate would be great. Because all these patients have been
extensively treated with other medication, the hurdle is set very high to see a
response ... These results are extraordinary."
Druker said all the patients in the study remain on treatment because
"we need to follow them to determine the long-term benefits and side
effects of this treatment." No one has discontinued medication because of
adverse side effects, he said. Side effects associated with treatment include
an upset stomach if the pills are taken on an empty stomach; some muscle cramps
were also reported.
In addition to the 31 patients, Druker said 28 other patients were placed on
the drug. One other patient in the overall study died of acute leukemia;
another patient underwent bone marrow transplantation.
The pharmaceutical company Novartis, based in Switzerland, has initiated the
next phase of studies for STI571 and is close to meeting a recruitment goal of
600 to 1,000 patients.