In the phase II trial, which is being conducted at several centers in the United States, researchers are attempting to determine if patients with multiple myeloma or non-Hodgkin's lymphoma who receive the drug AMD-3100 along with the standard drug G-CSF have more stem cells available for transplantation as compared to those who receive only G-CSF.
AMD-3100 blocks a specific cellular receptor, triggering the movement of stem cells out of the bone marrow and into the circulating blood, boosting the supply of stem cells from the bone marrow to be used in transplantation. Stem cell transplantation entails collecting certain types of cells known as hematopoietic stem cells from patients who receive treatment with high-dose radiation and/or chemotherapy for cancers such as leukemias, lymphomas and multiple myeloma, all of which involve the blood and immune system. The cells, once returned to the body, help restore the blood-forming system within the bone marrow – and the body's immune system, which is severely damaged if not destroyed by high-dose chemotherapy and/or radiation.
To date, every one of 19 patients given the drug combination were able to mobilize stem cells from the marrow to the bloodstream better than those who had G-CSF alone, says Neal Flomenberg, M.D., professor of medicine and director of medical oncology at Jefferson Medical College of Thomas Jefferson University, who oversees the trial at Jefferson. Dr. Flomenberg presents the trial's interim results December 7 at the American Society of Hematology's 45th Annual Meeting and Exposition in San Diego.
As a result, he says, there were fewer stem cell collections necessary and more stem cells retrieved. "This is the first time the drug combination has been tested in patients who have undergone chemotherapy, whose marrows have already been somewhat beaten up from prior treatment," Dr. Flomenberg says. "This is the acid test. These are the first patients whose cell products are being used for transplants."
Most patients undergo standard chemotherapy for four to eight months before they have a stem cell transplant, he explains. Some patients won't have a transplant until their disease relapses and treatment once again puts them back in remission. These treatments sometimes make subsequent stem cell collection difficult.
According to Dr. Flomenberg, stem cell transplantation is "front line therapy for multiple myeloma, or cancer of the bone marrow, and for high-risk lymphoma patients."
Approximately 25 percent to 35 percent of transplant patients have trouble moving stem cells from their bone marrow into the bloodstream using the standard drug, G-CSF. "Some patients with the standard approach don't mobilize well, meaning more collections and often a poor or unusable cell product," he says.
Dr. Flomenberg explains that based on results to date, the drug holds promise to cut down the number of stem cell collections patients need. The drug combination may both increase the number and improve the quality of cells collected. The greater the number of available stem cells, the more likely transplantation will be successful. In some cases, this can mean the difference between a patient being able to receive a transplant or not. The drug has little toxicity.
"I have a lot of hope that this drug will become a standard," he says.
The trial will enroll up to 24 cancer patients with either multiple myeloma or non-Hodgkin's lymphoma.
Other trial sites include Washington University in St. Louis, the University of Rochester, Virginia Commonwealth University in Richmond, Hackensack University Medical Center in Hackensack, N.J., and the Medical College of Wisconsin in Milwaukee.
The study is sponsored by AnorMED, Inc., a Vancouver, British Columbia-based drug development company. AnorMED's efforts are aimed at the discovery and development of small molecule therapeutics to treat diseases including HIV, rheumatoid arthritis, asthma and cancer.
For more information about the trial, please call 1-800-JEFF-NOW.
Contact:
Steve Benowitz or Phyllis Fisher
215-955-6300
After Hours: 215-955-6060
E-Mail: steven.benowitz@jefferson.edu