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Pivotal Study Leading to Gleevec'sTM Rapid Approval for CML Published

Pivotal Study Leading to Gleevec'sTM Rapid Approval for CML Published
Drug Found to Induce Hematologic, Cytogenetic Responses in Patients in Chronic Phase
M. D. Anderson News Release 02/27/02

Researchers at The University of Texas M. D. Anderson Cancer Center have published the pivotal study that demonstrates the success of Gleevec (formerly STI-571) in treating chronic myelogenous leukemia (CML) patients who had failed standard therapy.

The study, along with two other studies in advanced CML phases, resulted in the drug's approval in one of the fastest reviews ever for a cancer therapy by the U.S. Food and Drug Administration (FDA) in May 2001.

Dr. Hagop Kantarjian, professor and chairman of M. D. Anderson's Department of Leukemia is the lead author of the international study, which is published in the Feb. 28 issue of the New England Journal of Medicine.

"Our results from this study, in conjunction with two other trials testing Gleevec, were far better than we anticipated," said Dr. Kantarjian. "Our findings represent a dramatic improvement in the life expectancy in these patients for whom standard therapy has failed."

Gleevec was approved last May by the FDA for the treatment of CML, and is the first in a new class of drugs known as protein kinase inhibitors that is designed to selectively inhibit an enzyme involved in the development of the disease.

The Phase II non-randomized trial was conducted from Dec. 1999 through July 2001 at 28 centers in the United States and Europe, enrolling a total of 532 patients. All patients had failed standard interferon therapy after at least six months of treatment. M. D. Anderson enlisted nearly one-third of the trial participants, representing the largest participating site.

Patients took an oral regimen of one 400-milligram Gleevec pill a day and were evaluated for induction of major cytogenetic response, complete hematologic response, time to progression, survival and safety.

Study results found that the drug induced major cytogenetic responses - suppression of the Philadelphia-chromosome-positive cells known to cause the disease - in 60 percent of patients; while complete cytogenetic response was documented in 40 percent of patients. Complete hematologic responses (the disappearance of leukemic blood cells and return of normal cells) occurred in 95 percent of patients.

After 18 months, an estimated 89 percent of patients had not progressed to accelerated phase - or blast crisis - and 95 percent were still alive. Also at this time of analysis, 92 percent of the patients continued receiving Gleevec; eight percent had withdrawn due to disease progression.

"These findings represent a treatment breakthrough for patients with CML, as well as offer scientists a new direction for discovery. Gleevec is the first example of how successful targeted therapies can be in the treatment of cancer. The drug continues to show promise in treating earlier stages of CML and is currently being studied as a therapy for the treatment of other cancers," said Dr. Kantarjian.

According to the American Cancer Society, CML affects more than 4,500 patients a year. In the initial chronic phase of the disease, bone marrow transplantation is the only known cure for CML. However, many patients are not young or healthy enough to tolerate transplantation, which can cause serious side effects or death. 

"Before the use of this therapy, 15 to 20 percent of CML patients who had failed interferon therapy died each year. The fact that, with Gleevec, 95 percent of these patients are alive is a significant improvement," Dr. Kantarjian said.

Gleevec is produced by Novartis Pharmaceuticals who sponsored the clinical trial.


© 2015 The University of Texas MD Anderson Cancer Center