Immunosuppressive Therapy and Stem Cell Study for Multiple Sclerosis
Investigators have just released the interim results of a five-year study of high-dose immunosuppressive therapy (HDIT) and hematopoietic stem cell therapy in 24 individuals with multiple sclerosis. After three years, most of the participants showed improvements in neurological function and sustained remission of active relapsing-remitting MS (RRMS).
The new JAMA Neurology article reports the findings of the Hematopoietic Cell Transplantation for Relapsing-Remitting Multiple Sclerosis (HALT-MS) study. Basically, the idea is that use of HDIT supported by autologous (use of a patient’s own cells) hematopoietic stem cell infusions (transplantation) will stop disease activity in individuals who have poor prognosis RRMS.
In this study, autologous hematopoietic cell transplantation involved removing CD34 stem cells and storing them while the individuals were treated with high-dose immunosuppressive therapy; that is, the chemotherapy drugs carmustine, cytarabine, etoposide, and melphalan. The stored hematopoietic stem cells, which are responsible for the formation of blood, were then transfused into the patient’s bloodstream.
At the three-year evaluation point, the authors found that, without the use of any maintenance therapy:
- Overall rate of event-free survival (i.e., survival without loss of neurologic function, new lesions seen on imaging, or clinical relapse) was 78.4 percent
- Progression-free survival was 90.9 percent
- Clinical relapse-free survival was 86.3 percent
- Quality of life, functional scores, and neurological disability all also improved
The authors concluded that the combination of high-dose immunosuppressive therapy and hematopoietic stem cell transplantation “may represent a potential therapeutic option for patients with MS in whom conventional immunotherapy fails.” However, they also emphasized that “longer follow-up is needed to determine the durability of the response.”
This combination therapeutic approach is not without side effects. The most common adverse events were cytopenias (64%), infections (56%), gastrointestinal disorders (36%), metabolism disorders (32%), and nervous system issues (24%), such as headache.
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In a related editorial, two experts expressed their views on the use of immunosuppressive therapy and stem cell transplantation for MS patients. They noted that while the new study and a previous one “leave little doubt that high-dose immunotherapy is able to substantially suppress inflammatory disease activity in patients with MS who have active disease in the short term” and that there is “some evidence for long-term suppression of MS,” they had other concerns, including “the appropriateness and indication of HCT for MS.”
Thus the story of HDIT and HCT for multiple sclerosis is far from over but deserves careful attention. The five-year follow-up report from HALT-MS plus other research in this area will hopefully provide useful information that will improve treatment success.
Nash RA et al. High-dose immunosuppressive therapy and autologous hematopoietic cell transplantation for relapsing-remitting multiple sclerosis (HALT-MS). A 3-year interim report. JAMA Neurology 2014 Dec 29 published online. doi:10.1001/jamaneurol.2014.3780
Soldan MMP and Weinshenker BG. Moving targets for hematopoietic stem cell transplantation for multiple sclerosis. JAMA Neurology 2015; 72(2). DOI:10.1001/jamaneurol.2014.3831