High-dose immunosuppressive therapy plus stem cell transplant improves remission rates in relapsing-remitting MS

In patients with relapsing-remitting multiple sclerosis (MS), an experimental treatment consisting of high-dose immunosuppressive therapy followed by autologous stem cell transplantation may bring about sustained remission, according to the final 5-year results of the HALT-MS study, published online February 1 in Neurology.

“These extended findings suggest that one-time treatment with high-dose immunosuppressive therapy and autologous hematopoietic cell transplant (HDIT/HCT) may be substantially more effective than long-term treatment with the best available medications for people with a certain type of MS,” said National Institute of Allergy and Infectious Diseases (NIAID) Director Anthony S. Fauci, MD. “These encouraging results support the development of a large, randomized trial to directly compare HDIT/HCT to standard of care for this often-debilitating disease.”

In the HALT-MS study, researchers assessed the safety, efficacy, and durability of HDIT/HCT in 24 subjects aged 26 to 52 with relapsing-remitting MS, who were experiencing active inflammation comprised of frequent severe relapses and worse neurological disability, despite being on currently available treatment. A total of 24 patients underwent HDIT/HCT.

Researchers noted that the adverse events that occurred due to HDIT/HCT were consistent with expected toxicities; no late neurologic adverse events occurred.

Neurologic disability in patients who survived and completed the study showed improvement, with a median change in EDSS of -0.5 (interquartile range: -1.5 to 0.0; P=0.001).

After a median follow-up of 62 months, event-free survival (EFS)—the primary endpoint of the study—was 69.2% (90% CI: 50.2-82.1), progression-free survival 91.3% (90% CI: 74.7%-97.2%), clinical relapse-free survival 86.9% (90% CI: 69.5%-94.7%), and MRI activity-free survival was 86.3% (90% CI: 68.1%-94.5%).

“Although further evaluation of the benefits and risks of HDIT/HCT is needed, these five-year results suggest the promise of this treatment for inducing long-term, sustained remissions of poor-prognosis relapsing-remitting MS,” said Richard Nash, MD, of Colorado Blood Cancer Institute and Presbyterian-St. Luke’s Hospital. Dr. Nash served as principal investigator of the HALT-MS study.

“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,” said Daniel Rotrosen, MD, director of NIAID’s Division of Allergy, Immunology and Transplantation.

This work was sponsored by NIAID, NIH, and conducted by the ITN under award number AI109565 and NIAID-funded statistical and clinical coordinating centers under award number AI117870. The ClinicalTrials.gov identifier for the Phase 2 study High-Dose Immunosuppression and Autologous Transplantation for Multiple Sclerosis (HALT-MS) is NCT00288626.