Following Up on a Trial of an Immune System Reset to Treat Multiple Sclerosis

Some autoimmune diseases can be successfully treated by suppressing or destroying the existing immune system and then transplanting new stem cell populations responsible for generating immune cells. This can result in an effective resetting of the immune system, or at least removal of those parts of it that have become misconfigured to attack the patient's own tissues. It is, however, a pretty drastic process and certainly not one to be undertaken lightly: the sort of chemotherapy required is not a walk in the part for the patient. For autoimmune conditions where even partially effective alternative treatments exist, as is the case for rheumatoid arthritis, for example, researchers have all but abandoned work on the destroy-and-rebuild approach despite some early promising results. Nonetheless, it has been shown to produce results in terms of halting the progression of multiple sclerosis (MS), one of the more serious forms of autoimmunity in which the myelin sheathing of nerves is attacked:

Multiple sclerosis (MS) is a degenerative disease and most patients who receive disease-modifying therapies experience recurrence of the disease process. Three years after a small number of patients with MS were treated with high-dose immunosuppressive therapy (HDIT) and then transplanted with their own hematopoietic stem cells, most of the patients sustained remission of active relapsing-remitting MS (RRMS) and had improvements in neurological function.

Study results indicate that of the 24 patients who received HDIT/HCT, the overall rate of event-free survival was 78.4 percent at three years, which was defined as survival without death or disease from a loss of neurologic function, clinical relapse or new lesions observed on imaging. Progression-free survival and clinical relapse-free survival were 90.9 percent and 86.3 percent, respectively, at three years. The authors note that adverse events were consistent with the expected toxic effect of HDIT/HCT and that no acute treatment-related neurologic adverse events were seen. Improvements in neurologic disability, quality-of-life and functional scores also were noted.

"In the present study, HDIT/HCT induced remission of MS disease activity up to three years in most participants. It may therefore represent a potential therapeutic option for patients with MS in whom conventional immunotherapy fails, as well as for other severe immune-mediated diseases of the central nervous system. Most early toxic effects were hematologic and gastrointestinal and were expected and reversible. Longer follow-up is needed to determine the durability of the response."