Innovative Research Advances Stem Cell and Bone Marrow Transplantation

- Studies identify special considerations among children and adults

over 55 in need of stem cell transplants -

    ATLANTA, Dec. 10 /PRNewswire-USNewswire/ -- New data being presented at
 the 49th Annual Meeting of the American Society of Hematology in Atlanta,
 GA, suggest innovative strategies to improve the success of stem cell and
 bone marrow transplantation. These studies demonstrate improved outcomes
 using a new treatment regimen for children with a specific form of
 leukemia; new ways to increase the number of specialized stem cells
 harvested from the bone marrow prior to transplantation; efforts to
 effectively expand stem cell transplantation among patients older than 55;
 and preclinical research that re-examines the way physicians prepare a
 patient's immune system to accept a stem cell transplant. A press
 conference revealing this new research will take place Monday, December 10,
 from 8:00 to 9:00 a.m.
 
 
 
     "The data and discussion highlighted today give a glimpse into the
 great strides and promises of stem cell transplantation," said Armand
 Keating, MD, Princess Margaret Hospital, Toronto, Canada, and moderator of
 the transplantation press conference. "Stem cell transplantation is
 certainly not new, but advanced techniques and new ways of applying older
 technologies have the potential to change clinical practice and
 dramatically improve survival rates and quality of life for our patients
 whether young, old, or in the prime of their lives."
 
 
 
     Stem cells are the body's "parent" cells and can produce specialized
 cells that differentiate and become various tissues in the body, such as
 those found in the blood, immune system, heart, brain, and liver.
 Treatments used to fight cancer cells in the body often also devastate
 healthy cells and tissues, including stem cells, and the ability to
 extract, purify, and then reintroduce -- or transplant -- stem cells to
 patients following cell-destroying cancer treatments can help "rescue" a
 patient's compromised immune and hematologic system and speed his or her
 recovery.
 
 
 
 
 
     -- Children with a certain type of acute lymphoblastic leukemia who
 receive imatinib along with high-dose chemotherapy experienced improvements
 in survival [Abstract #4] -
 
 
 
     Kirk R. Schultz, MD, Child and Family Research Institute and the
 University of British
 
     Columbia, Vancouver, British Columbia, Canada
 
 
 
     *Abstract 4 is being presented on Sunday, December 9, at 2:30 p.m.
 during the Plenary
 
     Scientific Session (1:30 - 4:00 p.m.). The embargo will lift at that
 time.
 
 
 
     A Children's Oncology Group study examined whether increasing the
 number of days of imatinib (Gleevec (R)) therapy in combination with
 high-dose maintenance chemotherapy would improve early event-free survival
 in children with Philadelphia chromosome-positive acute lymphoblastic
 leukemia. A total of 93 children were enrolled in one of five cohorts,
 receiving imatinib for 42 days, 63 days, 84 days, 126 days, or 280 days,
 respectively, prior to maintenance chemotherapy. A bone marrow transplant
 was performed after two cycles of imatinib therapy only if a sibling donor
 was available; otherwise chemotherapy was continued. Patients who received
 a bone marrow transplant started imatinib four to six months following the
 transplant for six months.
 
 
 
 
 
     Increasing imatinib exposure resulted in improved early event-free
 survival at one year of 70.6 percent for the first and second cohorts, 90.9
 percent for the third and fourth cohorts, and 95.3 percent for the fifth
 cohort. The one-year event-free survival in cohort five, 65.7 percent, was
 significantly higher than had been seen in previous Children's Oncology
 Group studies.
 
 
 
     In conclusion, the study found that imatinib given in combination with
 intensive chemotherapy resulted in a significant improvement in early
 event-free survival. Imatinib given following a bone marrow transplant also
 improved early outcomes in related-donor bone marrow transplants. Intensive
 imatinib with intensive chemotherapy results in equivalent early event-free
 survival among patients treated with allogeneic-related or
 alternative-donor bone marrow transplants. Longer observation will be
 needed to see if these results produce a clinically significant difference
 in long-term event-free survival.
 
 
 
 
 
     -- Umbilical cord blood may be good source of stem cells for cancer
 patients older than 55
 
     [Abstract #331]
 
 
 
     Navneet S. Majhail, MD, University of Minnesota, Minneapolis, MN
 
 
 
 
 
     The aging of the Baby Boomer generation - every hour another 330
 Americans turn 60 - will have a tremendous impact on the prevalence of
 blood cancers and other disorders of the hematologic system in the years to
 come. Many older people with blood disorders may not be candidates for
 life-saving stem cell transplants because they cannot tolerate the steps
 needed to transplant stem cells harvested from their own bone marrow or
 cannot find donors who share their same genetic make-up. For these
 patients, stem cells from umbilical cord blood (UCB) may be a good
 alternative stem cell source.
 
 
 
     This study of 90 patients found that UCB was a viable source for stem
 cells for older patients who needed a transplant but did not have a matched
 related donor. The use of UCB and reduced- intensity immune system
 conditioning extended the availability of transplant therapy to older
 people previously excluded on the basis of age and lack of a suitable
 matched donor.
 
 
 
 
 
 
 
     -- Production of specialized stem cells increases when new compound is
 added to standard pre-transplantation routine for multiple myeloma patients
 [Abstract #445]
 
 
 
     John DiPersio, MD, PhD, Washington University School of Medicine, St.
 Louis, MO
 
 
 
 
 
     In order for a stem cell transplant to be successful, physicians must
 be able to extract -- or harvest -- an adequate number of specialized cells
 called CD34+ cells via a procedure known as apheresis. The CD34+ cells are
 purified following their extraction and re-introduced, or transplanted,
 back into the body following high-dose radiation or chemotherapies designed
 to kill the cancer cells in the body. Various medicines are given to
 patients to accelerate the production of CD34+ cells, and physicians
 continue to look for new ways to improve how quickly and how many of these
 cells can be produced.
 
 
 
     Interim results of a phase III, randomized, placebo-controlled trial
 concluded that the addition of the drug plerixafor to G-CSF therapy in
 patients with multiple myeloma results in a statistically significant
 increase in number of harvested CD34+ cells, and that transplants using
 these cells were durable at three months of follow-up. Patients receiving
 plerixafor +G-CSF were more than twice as likely to achieve target CD34+
 cell apheresis amounts compared with patients receiving G-CSF alone (72
 percent vs. 34 percent). These gains were seen without additional side
 effects for patients receiving the add-on drug treatment.
 
 
 
     -- Targeting a new antibody may lead to more tolerable transplantation
 procedures, according to early animal research [Late-Breaking Abstract
 #LB2]
 
 
 
     Agnieszka Czechowicz, Stanford University School of Medicine, Stanford,
 CA
 
 
 
 
 
     While stem cell transplants use the body's own immune system to repair
 the damage done by cancers or blood disorders and their treatments, the
 body's own remaining stem and immune cells often fight against a transplant
 and limit its effectiveness in helping a patient recover. In this animal
 study, a new model eliminated the myeloablative -- or cell-killing --
 conditioning regimens used in traditional stem cell transplants by
 targeting a special protein on the surface of cells - the C-kit antigen.
 
 
 
     To achieve these positive results, the researchers cultivated stem
 cells with a special antibody called ACK2, administering the antibody to
 mice. The ACK2-treated animals saw the rapid removal of more than 98
 percent of their own stem cells, and subsequent stem cell transplants in
 the mice were highly successful. This study could eventually define a new
 way of approaching bone marrow transplantation/hematopoietic stem cell
 transplantation (BMT/HSCT). Extrapolation of these methods to humans may
 enable efficient conditioning regimens for transplantation, thus expanding
 the potential applications of BMT/HSCT to include treatment of many
 non-malignant hematologic disorders and a wide variety of autoimmune
 disorders, such as diabetes and multiple sclerosis, as well as the
 facilitation of organ transplantation.
 
 
 
     The study authors and press program moderator will be available for
 interviews after the press program or by telephone. In addition to the
 press conference on transplantation, four additional press briefings will
 take place at the annual meeting focusing on blood clotting and bleeding
 disorders, leukemias, sickle cell disease and thalassemia, and hematologic
 malignancies. For the complete annual meeting schedule and additional
 information, please visit http://www.hematology.org/meetings/2007.
 
 
 
 
 
     The American Society of Hematology (http://www.hematology.org) is the
 world's largest professional society concerned with the causes and
 treatment of blood disorders. Its mission is to further the understanding,
 diagnosis, treatment, and prevention of disorders affecting blood, bone
 marrow, and the immunologic, hemostatic, and vascular systems, by promoting
 research, clinical care, education, training, and advocacy in hematology.
 
 
 
 
 
 
 
 
 
 
 

SOURCE American Society of Hematology