Impact of natalizumab on patient-reported outcomes in multiple sclerosis: a longitudinal study

Background: Natalizumab (Tysabri, Biogen Idec and Elan Pharmaceuticals) significantly reduces the relapse rate and disability progression, and improves health-related quality of life (HRQoL), in patients with relapsing-remitting multiple sclerosis. We investigated the impact of natalizumab on patient-reported outcomes (PROs) in a real-world setting. Methods: PRO data were collected from patients enrolled in a longitudinal real-world study using validated measures administered as surveys before the patients initiated natalizumab treatment and after the 3rd, 6th, and 12th monthly infusion. HRQoL, ability to carry out daily activities, disability level, and impact on cognitive functioning and fatigue were assessed. Results: A total of 333 patients completed 12 months of assessments. After 12 months of natalizumab treatment, 69% to 88% of patients reported a positive outcome (either an improvement or no further decline) in all PRO measures assessed. Significant improvements in general and disease-specific HRQoL were observed after three infusions, both with physical (p < .01) and psychological (p < .001) measures, and were sustained after 12 infusions (all p < .001). The impact of multiple sclerosis on cognitive functioning and fatigue was significantly reduced (both p < .001 after 3 and 12 infusions). Conclusions: PRO measures were improved with natalizumab in a real-world setting. The improvements were observed as early as after 3 months and sustained over a 12-month period. The improvements in PROs show that, in clinical practice, the clinical benefits of natalizumab are translated into patient-reported benefits.