Alemtuzumab treatment for multiple sclerosis in Austria: An observational long‐term outcome study

Abstract

Abstract Background/Objective Observational real‐world study to analyze the clinical effects of alemtuzumab (ALEM) and subsequent disease‐modifying therapy (DMT) usage in multiple sclerosis (MS). Methods Data retrieved from the Austrian MS treatment registry (AMSTR) included baseline (BL) characteristics (at ALEM start), annualized relapse rate (ARR), 6‐month confirmed progression independent of relapse activity (PIRA; ≥ 0.5‐point Expanded Disability Status Scale (EDSS) score increase), 6‐month confirmed disability improvement (CDI; ≥ 0.5‐point EDSS decrease), and safety outcomes until initiation of a subsequent DMT. The EDSS was re‐baselined at 30 days from ALEM start (BL EDSS). Results Eighty‐seven ALEM‐treated patients (median age: 32 years, 72% female, 14% treatment‐naïve) were followed for a median of 55 (interquartile range 31–68) months. We found significant reductions in the ARR from 1.16 before ALEM to 0.15 throughout Years 1–9 (p < 0.001). Subsequent DMTs were initiated in 19 patients (22%, 74% anti‐CD20 monoclonal antibodies). At Year 5 (n = 53), more patients achieved CDI (58%, 95% confidence interval (CI) 45%–71%) than had experienced PIRA (14%, CI 7.5%–24%), and 58% remained relapse‐free. Shorter MS duration (p < 0.001, hazard ratio (HR) 0.86 (CI 0.80–0.93)) and no previous high‐efficacy treatment (p < 0.001, HR 5.16 (CI 2.66–10.0)) were the best predictors of CDI, while PIRA was associated with a higher number of previous DMTs (p = 0.04, HR 3.06, CI 1.05–8.89). We found no new safety signals. Interpretation ALEM had long‐lasting beneficial effects on the ARR and disability improvement, especially when initiated early in the course of the disease. Only a subset of patients received subsequent DMTs.