Benefits of aHSCT over alemtuzumab in patients with multiple sclerosis besides disability and relapses: Sustained improvement in cognition and quality of life

Background: Autologous hematopoietic stem cell transplantation (aHSCT) exhibits promising results for multiple sclerosis (MS) in the short term. We investigated the long-term outcome differences in disease progression and cognitive impairment after aHSCT and alemtuzumab treatment. Methods: 20 patients receiving aHSCT and 21 patients treated with alemtuzumab between 2007 and 2020 were included in this monocentric observational cohort study. The primary objective was to compare the outcome of both groups with regards to achieving No Evidence of Disease Activity (NEDA-3), defined by the absence of relapses, EDSS progression, and MRI activity. Secondary endpoints in the study included the assessment of neurocognitive functioning, quality of life (QoL), Multiple Sclerosis Functional Composite (MSFC), and EDSS improvement. Results: Baseline characteristics between both groups were comparable, except for a longer disease duration in the alemtuzumab group of 11.3 years compared to 5.4 years in aHSCT-treated patients (p = 0.002) and a longer mean follow-up time in the aHSCT cohort of 9.0 (range 2.8-15.7) years compared to 5.9 years (range 0.9-9.2) in alemtuzumab patients. NEDA-3 was more frequently observed in the aHSCT group with 75.0 % and 55.0 % at five and 10 years, respectively, than in the alemtuzumab group with only 40.0 % at five years (p = 0.012). Relapse free survival was higher in the aHSCT group (p < 0.001). None of the aHSCT-treated patients showed new T2-lesions six months after therapy initiation until the end of the observational period in contrast to 35.0 % of the alemtuzumab-treated patients showing new T2-lesions (95 %CI 14.2-98.9, p = 0.002). aHSCT-treated patients showed significantly improved cognitive performance in five out of 12 cognitive tests whereas alemtuzumab treated patients deteriorated in four out of 12 tests. Quality of life remained on a constant level for up to 10 years in patients receiving aHSCT with improved scores for the subscale fatigue (p = 0.013). Conclusion: aHSCT seems to be superior to alemtuzumab in maintaining long-term NEDA-3 status, improving cognition and stabilizing quality of life for up to 10 years.