Edaravone (radical scavenger) versus sodium ozagrel (antiplatelet agent) in acute noncardioembolic ischemic stroke (EDO trial)

Edaravone, a free radical scavenger approved by the Japanese Ministry of Health, Labor and Welfare in 2001 for treating acute ischemic stroke, was recommended by the Japanese Guidelines for the Management of Stroke 2004. While edaravone also has a neuroprotective profile, there is no other recognized drug that can verify its effect in clinical trials despite the need for neuroprotection. We performed a postmarketing clinical trial to provide further reliable evidence concerning edaravone in patients with acute ischemic stroke.

We conducted a multicenter randomized parallel-group open-label trial of edaravone intravenously and a control drug, sodium ozagrel (ozagrel), a thromboxane A(2) synthase inhibitor, intravenously in acute noncardioembolic ischemic stroke. The primary endpoint was the modified Rankin Scale at 3 months after treatment initiation.

In total, 401 patients were initially enrolled. The rate of 'grade 0-1' on the modified Rankin Scale, as assessed at 3 months, was 57.1 and 50.3% in the edaravone and ozagrel groups, respectively. The intergroup difference was 6.8% (95% confidence interval = -3.1 to 16.7), indicating noninferiority of edaravone to ozagrel, since the lower limit of the confidence interval did not exceed -11.4%. There were no particular concerns over the safety of edaravone.

This trial verified that edaravone was not inferior to ozagrel. Edaravone was at least as effective as ozagrel for the treatment of acute noncardioembolic ischemic stroke.