Long-term clinical outcomes of hematopoietic stem cell transplantation in multiple sclerosis

Objective: To determine whether autologous hematopoietic stem cell transplantation (aHSCT) is able to induce durable disease remission in people with multiple sclerosis (MS), we analyzed the long-term outcomes after transplantation in a large cohort of patients with MS. Methods: To be included, a minimum dataset (consisting of age, MS phenotype, Expanded Disability Status Scale [EDSS] score at baseline, information on transplantation technology, and at least 1 follow-up visit after transplantation) was required. Results: Two hundred ten patients were included (relapsing-remitting [RR] MS 122 [58%]). Median baseline EDSS score was 6 (1-9); mean follow-up was 6.2 (±5.0) years. Among patients with RRMS, disability worsening-free survival (95% confidence interval [CI]) was 85.5% (76.9%-94.1%) at 5 years and 71.3% (57.8%-84.8%) at 10 years. In patients with progressive MS, disability worsening-free survival was 71.0% (59.4%-82.6%) and 57.2% (41.8%-72.7%) at 5 and 10 years, respectively. In patients with RRMS, EDSS significantly reduced after aHSCT (p = 0.001; mean EDSS change per year -0.09 [95% CI -0.15% to -0.04%]). In patients with RRMS, the use of the BCNU+Etoposide+Ara-C+Melphalan (BEAM) + anti-thymocyte globulin (ATG) conditioning protocol was independently associated with a reduced risk of no evidence of disease activity 3 failure (hazard ratio 0.27 [95% CI 0.14-0.50], p < 0.001). Three patients died within 100 days from aHSCT (1.4%); no deaths occurred in patients transplanted after 2007. Conclusions: aHSCT prevents disability worsening in the majority of patients and induces durable improvement in disability in patients with RRMS. The BEAM + ATG conditioning protocol is associated with a more pronounced suppression of clinical relapses and MRI inflammatory activity. Classification of evidence: This study provides Class IV evidence that for people with MS, aHSCT induces durable disease remission in most patients.