Long-Term Clinical Outcomes of Hematopoietic Stem Cell Transplantation in Multiple Sclerosis.

ABSTRACT

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 transplant in a large cohort of MS patients. METHODS: To be included, a minimum data set (consisting of age, MS phenotype, EDSS at baseline, information on transplant technology and at least 1 follow-up visit after transplant) was required. RESULTS: 210 patients were included [relapsing-remitting (RR)MS=122(58%)]. Median baseline EDSS was 6(1-9), mean follow-up was 6.2(±5.0) years. Among RRMS patients, disability worsening-free survival (95%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 RRMS patients, EDSS significantly reduced after aHSCT [p=0.001; mean EDSS change per year -0.09 (95%CI=-0.15 to -0.04%)]. In RRMS patients, the use of the BEAM+ATG conditioning protocol was independently associated with a reduced risk of NEDA-3 failure [HR=0.27(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.