Reduced Intensity Conditioning Regimens in Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis patients.

Abstract 2317

Poster Board II-294

High-dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation (AHSCT) offers promising results in the treatment of multiple sclerosis (MS) patients. Reduced intensity conditioning regimens (RIC-AHSCT) is a way to improve the balance between benefits and side effects of this treatment approach. The goal of our research was to study the safety and treatment outcomes of RIC-AHSCT in patients with various types of MS.

One hundred thirty six patients with MS: secondary progressive (SP) – 48 patients, primary progressive (PP) – 23, progressive-relapsing (PR) – 5 and relapsing-remitting (RR) – 60, were included in this study (mean age - 33.0, range: 17-54; male/female – 57/79). The conditioning regimen included reduced or modified BEAM. The median EDSS at base-line was 4.0 (range 1.5 – 8.5). The median follow-up duration was 17.2 months (range 6 – 35 months). Neurological evaluation was performed at baseline, at discharge, at 3, 6, 9, 12 months, and every 6 months thereafter AHSCT. MRI examinations were performed at baseline, at 6, 12 months, and at the end of follow-up.

No transplant-related deaths were observed. Transplantation procedure was well tolerated by the patients with no unpredictable severe adverse events. Among 91 patients included in the efficacy analysis 44 patients (48.5%) experienced clinical stabilization; 46 (50.5%) – improvement, and 1 patient (1%) – progression 6 months post-transplant. Among 31 SPMS patients 16 improved and 15 – stabilized; among 15 PPMS patients 7 improved, 7 – stabilized, and one progressed (PPMS); among 42 RRMS patients 20 improved and 22 – stabilized. In 12 months post-transplant 66% patients improved and 32% – stabilized. One patient (SPMS) progressed after 6 months stabilization. Relapses within the first year post-transplant were registered in 3 patients (2 SPMS; 1 PRMS). No active, new or enlarging lesions on MRI were registered in patients without disease progression.

In conclusion, this study provides ample evidence in support of safety and efficacy of reduced intensity conditioning AHSCT in patients with various types of MS. The collection of long-term follow-up data is worthwhile to verify these findings. The rationale of evolution from myeloablative to non-myeloablative transplant regimens should be confirmed by the further studies.