Natalizumab treatment of multiple sclerosis - a Danish nationwide study with 13 years of follow-up.

BACKGROUND: Natalizumab is a widely used high-efficacy treatment in multiple sclerosis (MS). Real-world evidence regarding long-term effectiveness and safety is warranted. We performed a nationwide study evaluating prescription patterns, effectiveness, and adverse events. METHODS: A nationwide cohort study using the Danish MS Registry. Patients initiating natalizumab between June 2006 and April 2020 were included. Patient characteristics, annualized relapse rates (ARRs), confirmed Expanded Disability Status Scale (EDSS) score worsening, MRI activity (new/enlarging T2- or gadolinium-enhancing lesions), and reported adverse events were evaluated. Further, prescription patterns and outcomes across different time periods ("epochs") were analysed. RESULTS: In total, 2424 patients were enrolled, with a median follow-up time of 2.7 years (interquartile range (IQR) 1.2-5.1). In recent epochs, patients were younger, had lower EDSS scores, had fewer pre-treatment relapses and were more often treatment naïve. At 13 years of follow-up, 36% had a confirmed EDSS worsening. On-treatment ARR was 0.30, corresponding to a 72% reduction from pre-initiation. MRI activity was rare, 6.8% had activity within 2-14 months from treatment start, 3.4% within 14-26 months, and 2.7% within 26-38 months. Approximately 14% of patients reported adverse events, with cephalalgia constituting the majority. During the study, 62.3% discontinued treatment. Of these, the main cause (41%) was due to JCV antibodies, while discontinuations due to disease activity (9%) or adverse events (9%) were less frequent. CONCLUSION: Natalizumab is increasingly used earlier in the disease course. Most patients treated with natalizumab are clinically stable with few adverse events. JCV antibodies constitute the main cause for discontinuation.

Alemtuzumab treatment in Denmark: A national study based on the Danish Multiple Sclerosis Registry.

OBJECTIVE: To investigate clinical outcomes in a real-world setting in the complete population-based cohort of alemtuzumab-treated MS patients in Denmark. METHODS: Data were retrieved from The Danish Multiple Sclerosis Registry between 2009 and 2019. Demographic and disease-specific patient parameters related to treatment history, efficacy, and safety outcomes were assessed at baseline and during follow-up visits. RESULTS: A total of 209 patients (78% female) started treatment with alemtuzumab during the study period with 3.1 ± 1.4 years follow-up. After 2 years, 75% of patients were relapse-free compared to 48% the year before alemtuzumab (p < 0.001). The annual number of relapses was reduced by 69% in year 4 compared with the year prior alemtuzumab. More active disease before alemtuzumab increased the annual hazard rate for relapse (HR: 2.88, p < 0.001). The Expanded Disability Status Scale (EDSS) score remained stable or improved in 81% of patients after 2 years. The need for an additional treatment course was associated with higher number of relapses in the year before alemtuzumab (odds ratio (OR) = 1.95, p = 0.001). CONCLUSION: In a country with primarily escalation strategy, relapse rate reduction was maintained for 5 years, and EDSS stabilized/improved in majority of patients. Higher relapse rate 1 year before alemtuzumab increased the odds for additional courses. Novel serious AEs were not observed.