AHSCT is an increasingly used treatment for aggressive forms of MS, the most common indication for any autoimmune disease.

Retrospective analysis of a cohort of patients with (pw)MS treated with AHSCT between 2002 and 2023 at 14 UK centres, excluding subjects in active trials. Effectiveness outcomes included relapse free survival (RFS), progression independent of relapse activity (PIRA), relapse associated worsening (RAW) and no evidence of disease progression (NEDA). A multivariate analysis was used to examine factors associated with PIRA and NEDA.

271 patients, median age of 40 years (range 19-66), of whom 153 (57%) were female, with a disease duration of 10 (range 6-14 years) and median EDSS of 6 (4-6.5) were included with a median follow up of 46 months (range 25-65). At baseline, 168 (62%) patients had relapsing-remitting MS (RRMS),  64 (24%) had secondary progressive MS and 39 (14%) had primary progressive MS.

RFS was 94% and 89% at 2 and 4 years after AHSCT. At the same timepoints, PIRA free survival was 91.4% and 68.7%, freedom from RAW was 99.2% and 99.2%, and NEDA was 72.0% and 54.7%, respectively. Patients with progressive MS had lower PIRA free survival (57.3%) than relapsing remitting MS (69.6%). Progressive MS was the only factor associated with PIRA (HR 1.68, 95% CI 1.05-2.69; p=0.032) and failure of NEDA (HR 1.62, 95% CI 1.13-2.33, p=0.009).

In this real-world cohort, AHSCT led to near-complete suppression of relapses and durable suppression of clinical progression. Ongoing randomised controlled trials are comparing the efficacy of AHSCT with high efficacy disease modifying therapy in RRMS, including STAR-MS in the UK.