Autologous hematopoietic stem cell transplantation with reduced-intensity conditioning in multiple sclerosis.

High-dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation (AHSCT) is a new and promising approach to multiple sclerosis (MS) treatment. In this article, we present the results of a prospective phase II open-label single-center study with the analysis of the safety and efficacy of high-dose immunosuppressive therapy+AHSCT with reduced-intensity conditioning regimen in 95 patients with different types of MS. The patients underwent early, conventional, and salvage/late transplantation. Efficacy was evaluated based on clinical and quality of life outcomes. No transplantation-related deaths were observed. The mobilization and transplantation procedures were well tolerated. All the patients, except one, responded to the treatment. At long-term follow-up (mean 46 months), the overall clinical response in terms of disease improvement or stabilization was 80%. The estimated progression-free survival at 5 years was 92% in the group after early AHSCT vs 73% in the group after conventional/salvage AHSCT. Statistically significant difference between the survival probabilities of two groups was determined (p = 0.01). No active, new, or enlarging lesions in magnetic resonance imaging were registered in patients without disease progression. All patients who did not have disease progression were off therapy throughout the post-transplantation period. AHSCT was accompanied by a significant improvement in patient's quality of life with statistically significant changes in the majority of quality of life parameters (p < 0.05).The results of our study support the feasibility of AHSCT with reduced-intensity conditioning in MS patients. Multicenter cooperative studies are needed for better assessment of treatment results and optimization of the treatment protocol of AHSCT with reduced-intensity conditioning regimens in MS.