Long-term outcomes of autologous haematopoietic stem cell transplantation in multiple sclerosis: A retrospective single-centre experience.

Background: Autologous haematopoietic stem cell transplantation (AHSCT) is a potential therapeutic strategy for patients with relapsing multiple sclerosis (pwRMS) unresponsive to disease-modifying therapies (DMTs), though its optimal position in the treatment algorithm remains undefined. Objective: To describe treatment outcomes of 30 AHSCT performed in 29 pwRMS. Methods: Retrospective single-centre real-world study. Patients underwent AHSCT between 2001 and 2025. Median age at disease onset, diagnosis, and AHSCT was 21, 23, and 32 years, respectively. Mean EDSS at AHSCT was 3.1 (range 1.0-9.0). Median follow-up was 8 years (range 0.5-20.6). Carmustine, etoposide, cytarabine, melphalan (BEAM) + anti-thymocyte globulin (ATG) was the most used high-dose chemotherapy regimen. Brain magnetic resonance imaging was performed at 6 months, 12 months, and then annually after AHSCT. Results: In patients with at least 6 months of follow-up, no evidence of disease activity-3 (NEDA-3) status was present in 16 out of 27 (59.2%); evidence of disease activity appeared after a median time of 33 months (range 5-74). NEDA-3 was maintained in 75% of the BEAM + ATG subgroup at the last follow-up. In the whole cohort, the mortality rate was 0%. Conclusions: AHSCT is a highly efficacious option for patients with hyperaggressive onset or highly active disease despite the high efficacy of DMTs.