Natalizumab May Improve Clinical Outcomes in Ischemic Stroke

MS IV infusion
MS IV infusion
Improvements in Rankin Scale score, Stroke Impact Scale-16, and Montreal Cognitive Assessment were observed in the treatment group.

LOS ANGELES — Treatment with natalizumab may help improve clinical outcomes after stroke, new data indicate.

The multiple sclerosis drug reduces acute brain inflammation, leading researchers in the ACTION trial to hypothesize that the antibody would help reduce infarct volume and improve clinical outcomes after acute ischemic stroke. The primary results were presented at the 2016 International Stroke Conference

The proof-of-concept, double-blind, phase 2 study evaluated the efficacy and safety of a single, 300 mg intravenous dose of natalizumab in patients with acute ischemic stroke. Patients were randomized to receive either natalizumab (n=79) or placebo (n=82) within 9 hours from last known normal. 

Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 12 and median time to treatment with natalizumab was 6 hours. Median baseline infarct volume was 23.68 mL in the natalizumab group and 23.41 mL in the placebo group. The primary endpoint of relative change in infarct volume from baseline to day 5 with treatment with natalizumab compared to placebo was not achieved (relative growth ratio: day 5, 1.09 [P=0.779]; day 30, 1.06 [P=0.684]), however secondary clinical outcomes appeared in favor of treatment with natalizumab.

The natalizumab group had good outcomes on the modified Rankin Scale (score ≤1 out of 0-6) at days 30 (odds ratio [OR] 2.88; 90% [prespecified] confidence interval [CI] 1.20-6.93) and 90 (OR 1.48; 90% CI 0.74-2.98) compared to the placebo group. Favorable outcomes for the natalizumab group were also achieved on the Barthel Index (score ≥95 out of 100) at day 90 (OR 1.91; 90% CI 1.07-3.41), the Stroke Impact Scale-16, and the Montreal Cognitive Assessment. No between-group differences were observed for NIHSS score, and incidences of death and serious adverse events were similar for both groups (natalizumab 18% vs placebo 16%; 46% vs 46%, respectively).

Although the primary endpoint was not achieved, improvements in clinical outcomes seen in the natalizumab group warrant further investigation of its role in the treatment of acute ischemic stroke.

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Elkins J, Elkind MS, Veltkamp R, et al. LB22. Primary Results of the ACTION Trial of Natalizumab in Acute Ischemic Stroke (AIS). Presented at: International Stroke Conference; Feb. 16-19, 2016; Los Angeles.