Association of Nonmyeloablative Hematopoietic Stem Cell Transplantation with Neurological Disability in Patients with Relapsing-Remitting Multiple Sclerosis.

IMPORTANCE:No current therapy for relapsing-remitting multiple sclerosis (MS) results in significant reversal of disability.OBJECTIVE:To determine the association of nonmyeloablative hematopoietic stem cell transplantation with neurological disability and other clinical outcomes in patients with MS.DESIGN, SETTING, AND PARTICIPANTS:Case series of patients with relapsing-remitting MS (n = 123) or secondary-progressive MS (n = 28) (mean age, 36 years; range, 18-60 years; 85 women) treated at a single US institution between 2003 and 2014 and followed up for 5 years. Final follow-up was completed in June 2014.INTERVENTIONS:Treatment with cyclophosphamide and alemtuzumab (22 patients) or cyclophosphamide and thymoglobulin (129 patients) followed by infusion of unmanipulated peripheral blood stem cells.MAIN OUTCOMES AND MEASURES:Primary end point was reversal or progression of disability measured by change in the Expanded Disability Status Scale (EDSS) score of 1.0 or greater (score range, 0-10). Secondary outcomes included changes in the Neurologic Rating Scale (NRS) score of 10 or greater (score range, 0-100), Multiple Sclerosis Functional Composite (MSFC) score, quality-of-life Short Form 36 questionnaire scores, and T2 lesion volume on brain magnetic resonance imaging scan.RESULTS:Outcome analysis was available for 145 patients with a median follow-up of 2 years and a mean of 2.5 years. Scores from the EDSS improved significantly from a pretransplant median of 4.0 to 3.0 (interquartile range [IQR], 1.5 to 4.0; n = 82) at 2 years and to 2.5 (IQR, 1.9 to 4.5; n = 36) at 4 years (P < .001 at each assessment). There was significant improvement in disability (decrease in EDSS score of ≥1.0) in 41 patients (50%; 95% CI, 39% to 61%) at 2 years and in 23 patients (64%; 95% CI, 46% to 79%) at 4 years. Four-year relapse-free survival was 80% and progression-free survival was 87%. The NRS scores improved significantly from a pretransplant median of 74 to 88.0 (IQR, 77.3 to 93.0; n = 78) at 2 years and to 87.5 (IQR, 75.0 to 93.8; n = 34) at 4 years (P < .001 at each assessment). The median MSFC scores were 0.38 (IQR, -0.01 to 0.64) at 2 years (P < .001) and 0.45 (0.04 to 0.60) at 4 years (P = .02). Total quality-of-life scores improved from a mean of 46 (95% CI, 43 to 49) pretransplant to 64 (95% CI, 61 to 68) at a median follow-up of 2 years posttransplant (n = 132) (P < .001). There was a decrease in T2 lesion volume from a pretransplant median of 8.57 cm3 (IQR, 2.78 to 22.08 cm3) to 5.74 cm3 (IQR, 1.88 to 14.45 cm3) (P < .001) at the last posttransplant assessment (mean follow-up, 27 months; n = 128).CONCLUSIONS AND RELEVANCE:Among patients with relapsing-remitting MS, nonmyeloablative hematopoietic stem cell transplantation was associated with improvement in neurological disability and other clinical outcomes. These preliminary findings from this uncontrolled study require confirmation in randomized trials.