April 17, 2002
Researchers from the University of Washington (Seattle) presented preliminary findings from a study of transplantation of blood stem cells in 26 individuals with severe, progressive MS:
Dr. George Kraft and other investigators from the University of Washington Medical Center, Seattle, reported findings from a preliminary study of transplantation of blood stem cells in 26 individuals with different forms of severe, progressive MS. All patients in the study had experienced significant progression of their disease in the year prior to entry into the study and most had not benefited from other types of treatment. This radical and expensive therapy—which was originally developed and is most commonly used to treat cancer—is also known as hemopoietic stem cell transplantation (HSCT) or bone marrow transplantation or autologous stem cell transplantation. The results, presented on April 16, 2002 during the American Academy of Neurology’s annual meeting in Denver, suggest that larger and longer controlled studies are needed to adequately assess the safety and potential benefits of HSCT for multiple sclerosis.
HSCT involves removing and storing blood stem cells (which are different than embryonic stem cells) from the individual’s blood, then destroying most of the remaining immune system cells by radiation and/or chemotherapy. Dr. Kraft’s study used chemotherapy. The stored blood stem cells are then returned to the individual’s blood so that they will mature into a new immune system. It is hoped that the reconstituted immune system will be free from abnormalities that may underlie MS. While the new immune system is developing, the individual is susceptible to infection and bleeding, which is one of the aspects of this therapy that makes it potentially life-threatening.
Dr. Kraft’s team has thus far followed the study participants for an average of over one year after the HSCT. According to the presentation, 20 out of 26 patients in the study appeared to stabilize. However, a longer period of observation is required to know whether this stabilization will continue. One of the study participants died from complications related to the procedure. Previous experience with HSCT in persons with MS suggests that the fatality rate ranges from five to ten percent—higher than that in persons who have undergone this procedure to treat cancer. The risk of fatality is what makes many physicians cautious about using HSCT as a treatment for most individuals who have multiple sclerosis, because MS is generally not a fatal disease. HSCT is also expensive, costing approximately $100,000.
Larger-scale and longer-term clinical trials of HSCT are planned and ongoing. The jury is still out on its safety and effectiveness for persons with MS. Individuals interested in this experimental therapy should discuss HSCT with their physicians.
The National MS Society’s Winter/Spring 2002 issue of “Research Highlights” contains a thorough description of HSCT in multiple sclerosis. The article is available on the Society’s Web site at: http://www.nationalmssociety.org/Highlights-BoneMarrow.asp
—Research Programs Department
© 2002 The National Multiple Sclerosis Society