UT Southwestern researchers seek patients with rare type of leukemia for new drug trial
DALLAS — Jan. 19, 2006 — Lourdes Cal's bout with chronic myelogenous leukemia (CML), a rare type of blood cancer, took a turn for the worse last summer. When Mrs. Cal saw
UT Southwestern Medical Center emergency physicians July 8, she had an elevated white cell count five times the normal level.
Five months later, thanks to her treatment with the chemotherapy drug Dasatinib at the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern, Mrs. Cal said she is feeling healthy again.
"Within a few months, her leukemia would have become fatal," said
Dr. Robert Collins, director of the UT Southwestern Hematopoietic Cell Transplant Program who has used Dasatinib to successfully treat the eight CML patients that have come to him, ranging in age from 35 to 75.
Other patients in her situation can join a clinical trial to receive Dasatinib at UT Southwestern, the only site in North Texas where CML patients can obtain the new drug, Dr. Collins said.
In the ongoing clinical trial, Dr. Collins and other investigators at several medical centers nationwide are administering Dasatinib in randomized doses to patients who do not respond to the standard treatment with the chemotherapy drug Gleevec. Researchers observe the anti-cancer effect of the treatment.
Mrs. Cal, a Dallas homemaker, is one of the estimated 10 percent of CML patients who develop a resistance to Gleevec. In those with CML, a defective gene called BCR-ABL produces an enzyme that causes white blood cells to proliferate out of control and, ultimately, destroy the body's immune system. The mother of four, diagnosed with CML in 2001, hoped that Gleevec would keep her cancer in check. It worked well for a few years, but then Mrs. Cal became resistant to the drug.
"She's had a really nice response to Dasatinib," said Dr. Collins. "The last time we conducted a bone marrow test there was no evidence of the abnormal chromosome that characterizes her leukemia."
During a recent checkup, Mrs. Cal said she felt "very grateful; I know that not many people get this opportunity. My family is very excited for me."
CML may be the best understood cancer on a molecular level, and Dr. Collins said the mechanism-driven approach researchers have taken to attack this strain with targeted therapeutic drugs is bound to become a model for attacking other cancers as well.
About 4,000 patients are annually diagnosed with CML in the United States. The only known cure is a bone-marrow transplant from a healthy donor. However, often there are serious side effects if the donor immune cells attack the patient's and cause graft-versus-host disease, Dr. Collins said. Therapeutic intervention with chemotherapy drugs is the most promising avenue for most CML patients, he said.
The second phase of clinical trials of Dasatinib began in early 2005. Interested CML patients or physicians seeking to refer a patient for the clinical trial at UT Southwestern should contact Dr. Collins' office at 214-648-4155.
Visit http://www.utsouthwestern.org/cancercenter to learn more about UT Southwestern’s clinical services in cancer.