Multiple Sclerosis or MS is a potentially disabling disease of the brain and spinal cord (central nervous system). In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause the nerves themselves to deteriorate or become permanently damaged.
MS symptoms vary widely and may include motor and speech difficulties, weakness, fatigue and chronic pain. The most common form of MS is relapsing-remitting MS, which is characterized by periods of mild or no symptoms interspersed with symptom flare-ups or relapses. Over time, the disease can worsen and shift to a progressive form.
New clinical trial results provide evidence that high-dose immunosuppressive therapy followed by transplantation of a person’s own blood-forming stem cells can bring about sustained remission of relapsing-remitting MS. The trial called HALT-MS was sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and conducted by the NIAID-funded Immune Tolerance Network (ITN). Researchers published three-year results from the study in December 2014, and the final five-year results appeared online Feb. 1 in Neurology, the medical journal of the American Academy of Neurology.
Five years after receiving the treatment, called high-dose immunosuppressive therapy and autologous hematopoietic cell transplant (HDIT/HCT), 69 percent of trial participants had survived without experiencing progression of the disability, relapse of MS symptoms or new brain lesions. Notably, participants did not take any MS medications after receiving HDIT/HCT. Other studies have indicated that currently available MS drugs have lower success rates.
These findings suggest that one-time treatment with HDIT/HCT may be more effective than long-term treatment with the best available medications for people with a certain type of MS.
In HALT-MS, researchers tested the safety, efficacy and durability of HDIT/HCT in 24 volunteers aged 26 to 52 years with relapsing-remitting MS who, despite taking clinically available medications, experienced active inflammation, evidenced by frequent severe relapses, and worsened neurological disability.
The experimental treatment aims to suppress active disease and prevent further disability by removing disease-causing cells and resetting the immune system. During the procedure, doctors collect a participant’s blood-forming stem cells, give the participant high-dose chemotherapy to deplete the immune system, and return the participant’s own stem cells to rebuild the immune system.
Five years after HDIT/HCT, most trial participants remained in remission, and their MS had stabilized. In addition, some participants showed improvements, such as recovery of mobility or other physical capabilities.
Although further evaluation of the benefits and risks of HDIT/HCT is needed, these results suggest the promise of this treatment for inducing long-term, sustained emissions of poor-prognosis relapsing-remitting MS.
If these findings are confirmed in larger studies, HDIT/HCT may become a potential therapeutic option for patients with active relapsing-remitting MS, particularly those who do not respond to existing therapies.