San Diego --
December 12, 2011
Patients who receive a blood stem cell transplant from a donor outside of their family to treat leukemia and other blood diseases are more likely to have graft failure but less likely to experience graft-versus-host disease if the transplanted blood cells come directly from a donor’s bone marrow, rather than from circulating peripheral blood stem cells (PBSCs), according to new research.
Although the study showed differences in the type and extent of complications, the results showed no difference in patient survival rates between these two major sources of donated blood cells. The study, presented in the plenary session of the 53rd annual American Society of Hematology conference in San Diego, was conducted by the Blood and Marrow Transplant Clinical Trials Network (BMT CTN).
This randomized study, the first to compare outcomes in unrelated transplants, included nearly 50 transplant centers in the United States and Canada. It compared two-year survival rates for 273 patients receiving PBSC with 278 patients receiving bone marrow. The study found that survival was the same using either blood cell source, but the complications following transplant were different depending on which source was used.
PBSCs resulted in better engraftment than bone marrow, but were associated with higher rates of chronic graft-versus-host-disease (GVHD) (53 percent compared with 40 percent in bone marrow), and the GVHD was also more extensive. GVHD is a serious and often deadly post-transplant complication that occurs when the newly transplanted donor cells recognize the recipient’s own cells as foreign and attack them.
“This was an important study to conduct in a randomized, prospective manner. This new research confirms much of what we had seen previously, but now gives patients, donors and physicians more concrete evidence to consider when deciding on the course of treatment,” said Dr. Dennis Confer, National Marrow Donor Program (NMDP) chief medical officer, who co-authored the study.
“Our trial demonstrates that bone marrow and PBSC result in similar patient survival. While PBSCs result in better engraftment, this did not lead to a survival benefit in our study follow-up period, but did show an increased risk for chronic GVHD,” said lead study author Claudio Anasetti, M.D., chair of the Department of Blood & Marrow Transplant at Moffitt Cancer Center in Tampa, Fla. “More effective strategies to prevent GVHD are needed to improve outcomes in these patients.”
The BMT CTN – a collaboration between the NMDP, the CIBMTR (Center for International Blood and Marrow Transplant Research), the EMMES Corporation, and transplant centers throughout United States and Canada – performed the prospective, randomized study to determine if the source of the stem cell graft, whether PBSCs or bone marrow, affects transplant outcomes in patients whose donors are unrelated. Approximately 70 percent of patients who need an allogeneic transplant do not have a matching donor in their family and depend on an unrelated donor.
This study was supported with funding from National Heart, Lung, and Blood Institute (NHLBI), National Cancer Institute (NCI), National Marrow Donor Program (NMDP) and the Office of Naval Research and Health Resources and Services Administration (HRSA).
PBSCs are stem cells originally found in the bone marrow that have been moved, or mobilized, into the donor’s blood stream by a special regimen of drugs. Through a process called apheresis, a donor's blood is removed through a needle in one arm and passed through a machine that separates out the blood-forming stem cells. The remaining blood is returned to the donor through the other arm. Bone marrow, which contains blood and stem cells, is collected from the marrow cavity of the donor’s hipbone during a surgical procedure.
About the BMT CTN
The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) was established because of a critical need for multi-institutional clinical trials focused directly on improving survival for patients undergoing hematopoietic cell transplantation (HCT). Since 2001, the BMT CTN has opened more than 27 multi-institutional phase II and III trials, involved more than 100 transplant centers, and enrolled thousands of patients.
BMT CTN is funded by NHLBI and NCI at the National Institutes of Health (NIH) and is a collaborative effort of 20 Core Transplant Centers/Consortia, the CIBMTR, the NMDP, and the EMMES Corporation. Collectively, CIBMTR, NMDP and EMMES serve as the BMT CTN Data and Coordinating Center to provide administrative, statistical, scientific, and informatics support to all BMT CTN activities. The CIBMTR is a combined research program of the Medical College of Wisconsin and the National Marrow Donor Program.