Comparison of BEAM and Cyclophosphamide in ASCT for Relapsing-Remitting MS
Overview
This study compares the efficacy and safety of two conditioning regimens, BEAM/ATG and Cy/ATG, used in autologous hematopoietic stem cell transplantation (ASCT) for relapsing-remitting multiple sclerosis (RRMS). Using data from the Swedish AutoMS-Swe observational study, outcomes including no evidence of disease activity (NEDA), relapse rates, disability progression, and adverse events were analyzed.
Background
Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system, with relapsing-remitting MS (RRMS) being the primary target for disease-modifying treatments. Autologous hematopoietic stem cell transplantation (ASCT) has emerged as a therapeutic option, initially developed for hematological malignancies and later adapted for autoimmune diseases including MS. Conditioning regimens prior to ASCT have evolved from high-intensity to intermediate-intensity protocols, with BEAM/ATG and Cy/ATG being the most commonly used. Both regimens aim to induce remission by immune ablation but differ in intensity and toxicity profiles.
Data Highlights
Parameter
BEAM/ATG
Cy/ATG
Conditioning Duration
7 days
5 days
ATG Dose
10 mg/kg total
6 mg/kg total
Stem Cell Mobilization
G-CSF 5 µg/kg + Cyclophosphamide 2 g/m2
G-CSF 5 µg/kg + Cyclophosphamide 2 g/m2
Washout Time Before Reinfusion
48 hours
24 hours
Follow-up Duration for Primary Endpoint
5 years
Key Findings
Both BEAM/ATG and Cy/ATG conditioning regimens induce high rates of clinical remission in RRMS patients undergoing ASCT.
BEAM/ATG is a myeloablative regimen administered over 7 days, while Cy/ATG is an immunoablative, non-myeloablative regimen given over 5 days with additional methylprednisolone.
Safety profiles differ, with earlier high-intensity regimens associated with higher toxicity; intermediate-intensity regimens like BEAM and Cy have improved safety.
Both regimens are typically combined with T-cell depleting serotherapy (ATG) to enhance immune ablation.
Prophylactic antimicrobial strategies are employed during neutropenia to reduce infection risk, including ciprofloxacin, antiviral, and Pneumocystis jiroveci prophylaxis.
Primary endpoints include no evidence of disease activity (NEDA) at 5 years and treatment-related mortality, with secondary endpoints assessing relapse rates, disability progression, and MRI activity.
Clinical Implications
Clinicians should consider both BEAM/ATG and Cy/ATG as effective conditioning regimens for ASCT in RRMS, balancing efficacy with safety profiles. The choice of regimen may be influenced by patient-specific factors and center experience. Prophylactic antimicrobial measures and close monitoring during the neutropenic phase are essential to minimize complications.
Conclusion
ASCT with either BEAM/ATG or Cy/ATG conditioning offers a promising treatment for RRMS, achieving high remission rates with improved safety compared to earlier protocols. Further comparative data will help refine regimen selection to optimize patient outcomes.
References
AutoMS-Swe Study Group 2024 -- Comparison of BEAM and Cyclophosphamide in ASCT for RRMS
