Effectiveness of natalizumab in patients with highly active relapsing remitting multiple sclerosis

We evaluated the effectiveness of natalizumab in patients with highly active, relapsing-remitting multiple sclerosis (HA-RRMS) to identify baseline predictors associated with freedom from disease activity.

We analyzed 70 patients treated with natalizumab and followed for at least 1 year with progression of disability of ≥1 point on the EDSS before starting therapy. We recorded freedom from clinical activity, radiological activity, and disease activity (clinical and radiological).

The median (IQR) follow-up was 2.3 (2.0-3.8) years. Of the 52 patients who completed 2 years of treatment, 25 were free of disease activity (48.1%). The ARR decreased from a mean ± SD of 2.49 ± 0.86 at baseline to 0.47 ± 0.83 at the end of the first year (p < 0.001) and 0.34 ± 0.69 at the end of the second year (p < 0.001). The percentage of patients with gadolinium-enhanced lesions decreased from 21 at baseline to 5.7 at the end of the first year (p < 0.001) and to 5.8 during the second year (p < 0.005). Baseline EDSS ≤3.0 was significantly associated with freedom from disease activity (OR, 2.49; 95% CI, 1.24-4.99; p = 0.010).

Natalizumab is effective in patients with HA-RRMS. Baseline EDSS ≤3.0 increases the probability of remaining disease-free in HA-RRMS treated with natalizumab.