"New clinical trial results provide evidence that highdose immunosuppressive therapy followed by transplantation of a persons own bloodforming stem cells can induce sustained remission of relapsingremitting multiple sclerosis MS an autoimmune disease in which the immune system attacks the central nervous system. ...these fiveyear results suggest the promise of this treatment for inducing longterm sustained remissions of poorprognosis relapsingremitting MS. Richard Nash M.D. Principal iInvestigator HALTMS study Five years after receiving the treatment called highdose immunosuppressive therapy and autologous hematopoietic cell transplant HDITHCT  percent of trial participants had survived without experiencing progression of disability relapse of MS symptoms or new brain lesions. Notably participants did not take any MS medications after receiving HDITHCT. Other studies have indicated that currently available MS drugs have lower success rates. The trial called HALTMS was sponsored by the National Institute of Allergy and Infectious Diseases NIAID part of the National Institutes of Health and conducted by the NIAIDfunded Immune Tolerance Network link is external https ITN. The researchers published threeyear results https from the study in December  and the final fiveyear results appear online Feb.  in Neurology the medical journal of the American Academy of Neurology. These extended findings suggest that onetime treatment with HDITHCT may be substantially more effective than longterm treatment with the best available medications for people with a certain type of MS said NIAID Director Anthony S. Fauci M.D. These encouraging results support the development of a large randomized trial to directly compare HDITHCT to standard of care for this oftendebilitating disease. MS symptoms vary widely and may include motor and speech difficulties weakness fatigue and chronic pain. The most common form of MS is relapsingremitting MS which is characterized by periods of mild or no symptoms interspersed with symptom flareups or relapses. Over years the disease can worsen and shift to a progressive form.  In HALTMS researchers tested the safety efficacy and durability of HDITHCT in  volunteers aged  to  years with relapsingremitting 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 diseasecausing cells and resetting the immune system. During the procedure doctors collect a participants bloodforming stem cells give the participant highdose chemotherapy to deplete the immune system and return the participants own stem cells to rebuild the immune system. The treatment carries some risks and many participants experienced the expected side effects of HDITHCT such as infections. Three participants died during the study none of the deaths were related to the study treatment. Five years after HDITHCT 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 HDITHCT is needed these fiveyear results suggest the promise of this treatment for inducing longterm sustained remissions of poorprognosis relapsingremitting MS said Richard Nash M.D. of Colorado Blood Cancer Institute and PresbyterianSt. Lukes Hospital. Dr. Nash served as principal investigator of the HALTMS study. If these findings are confirmed in larger studies HDITHCT may become a potential therapeutic option for patients with active relapsingremitting MS particularly those who do not respond to existing therapies said Daniel Rotrosen M.D. director of NIAIDs Division of Allergy Immunology and Transplantation. This work was sponsored by NIAID NIH and conducted by the ITN under award number AI and NIAIDfunded statistical and clinical coordinating centers under award number AI. The ClinicalTrials.gov identifier for the Phase  study HighDose Immunosuppression and Autologous Transplantation for Multiple Sclerosis HALTMS is NCT httpsclinicaltrials.govctshowNCT. NIAID conducts and supports research  at NIH throughout the United States and worldwide  to study the causes of infectious and immunemediated diseases and to develop better means of preventing diagnosing and treating these illnesses. News releases fact sheets and other NIAIDrelated materials are available on the NIAID website https About the National Institutes of Health NIH NIH the nations medical research agency includes  Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic clinical and translational medical research and is investigating the causes treatments and cures for both common and rare diseases. For more information about NIH and its programs visit  https NIHTurning Discovery Into Health Reference RA Nash et al. Highdose immunosuppressive therapy and autologous HCT for relapsingremitting MS. Neurology DOI .WNL. ."