Taking blood stem cells collected from an umbilical cord into the lab and expanding their number before transplanting them to replace a patient's blood supply is as safe as a standard cord blood transplant, researchers reported today at the 50th Annual Meeting of the American Society of Hematology.
In a first-of-its-kind randomized clinical trial, researchers at The University of Texas M. D. Anderson Cancer Center are addressing the critical challenge to successful "standard" cord blood transplants for adult patients - low doses of stem cells that lead to longer recovery times, leaving patients more vulnerable to bleeding, infection and transplant failure.
The clinical trial randomized 71 patients with advanced leukemias or lymphomas into either a standard cord blood transplant, in which a patient receives blood stem cells from two umbilical cords, or to a second group that receives regular cells from one cord plus cells from a second cord that were exposed to growth factors in the lab to expand their number.
Patients with recurrent, high-risk acute myeloid leukemia, acute lymphocytic leukemia, chronic myelogenous leukemia, many types of lymphoma, aplastic anemia and other genetic and immunologic disorders require blood stem cell transplants to rebuild their blood supply after intense chemotherapy or as a therapeutic attack on their disease.
A transplant of bone marrow-derived stem cells from a perfectly matched donor is the optimum course of treatment because a large volume of cells is transplanted, leading to rapid engraftment and fewer side effects. Finding a required perfect match of six human leukocyte antigen (HLA) genes between donor and patient can be prohibitively difficult. Generally speaking, cord blood stem cells are easily collected, readily available, and do not require a perfect HLA gene match due to their immaturity.
The study's senior scientist, Elizabeth Shpall, M.D., professor in Stem Cell Transplantation and Cell Biology, has opened a new phase II study that involves growing the cord blood stem cells on a framework of supportive mesenchymal stromal cells while exposing them to growth-promoting cytokines. This approach might more closely simulate the bone marrow microenvironment where stem cells are produced.
Adapted from the University of Texas M.D. Anderson Cancer Center announcement.