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

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.