Autologous hematopoietic stem cell transplantation was an effective treatment option for aggressive multiple sclerosis, particularly in patients with inflammatory activity at baseline, in a study of the Swedish experience with the procedure since it was first performed there in 2004.
A prospective, observational study of 41 patients with MS treated with autologous hematopoietic stem cell transplantation (HCST) showed a 5-year, relapse-free survival rate of 87% and disease-free survival of 68%. The data also showed a magnetic resonance imaging (MRI) event-free survival rate of 85% and expanded disability status scale (EDSS) score progression-free survival of 77%.
"We know that HSCT causes a profound renewal of the immune system and not just long-lasting immune suppression," wrote first author Dr. Joachim Burman from Uppsala (Sweden) University Hospital and his colleagues. "At least part of the effect is likely related to removal of autoreactive cells, but some of these cells probably escape the treatment and remain after HSCT."
Autologous HSCT has been used to treat MS for nearly two decades and was initially used to treat progressive forms of MS, but when the procedure did not stop deterioration in patients with progressive disease, researchers found that it could be effective in treating highly aggressive relapsing-remitting MS. However, no randomized controlled trial has been performed, few case series have been published, and systematic safety and efficacy follow-up data for relapsing-remitting MS are scarce, the authors noted.
In the study, patients with ongoing inflammatory activity at baseline showed the most significant treatment response, and 79% of these patients had no new MRI lesions, relapses, or EDSS score progression following treatment.
The EDSS score improved in relapsing-remitting patients from a median of 5.5 at the time of HSCT to 3.25 at 1 year and 3 at 2 years, and in those with progressive forms of MS the median score stayed at 6.5 at those three time points.
Of the 41 patients, 34 had relapsing-remitting MS and 7 had other progressive forms of MS. All of the patients had at least 1 year of follow-up, and the mean duration was 47.4 months (J. Neurol. Neurosurg. Psychiatr. 2014 Feb. 19 [doi: 10.1136/jnnp-2013-307207]).
Researchers noted that new disease activity, when it did occur, was predominantly seen during the first 2 years after treatment, and no patient who remained disease-free during the first 3 years – meaning no relapses, no new MRI lesions, and no EDSS progression – went on to have a clinical relapse or develop new MRI lesions.
No deaths were associated with the treatment, although almost all patients experienced acute toxicity during hospitalization. The most common long-term side effects were herpes zoster reactivation (15%) and thyroid disease (8.4%).
The research was supported by the Swedish Association of Persons with Neurological Disabilities, the MÅH Ländell Foundation, and Uppsala University Hospital. The authors declared individual funding, support, and grants from a range of pharmaceutical companies.