Hyperacute treatment initiation in neuroprotective agent stroke trials

Area of Science:

• Neuroscience
• Clinical Trials
• Stroke Research

Background:

• Late treatment initiation is a key factor in the failure of neuroprotective drugs for acute ischemic stroke.
• Animal studies indicate an optimal therapeutic window of 1-3 hours post-ischemia for neuroprotection.
• Previous human studies have not quantified early treatment initiation rates in stroke trials.

Purpose of the Study:

• To analyze the frequency of patient enrollment within the first 1, 2, and 3 hours in human neuroprotective stroke clinical trials.
• To assess the timeliness of treatment initiation in acute ischemic stroke trials.

Main Methods:

• Systematic literature review of 30 phase 3 neuroprotective trials (1990-2001).
• Data collected via questionnaire from principal investigators on patient enrollment epochs: 0-60, 61-120, 121-180, and 181-360 minutes.
• Analysis focused on patient numbers within specific timeframes after ischemia onset.

Main Results:

• Data from 6 trials (5345 patients) were analyzed.
• Less than 2% of patients in trials with <6-hour windows received treatment within 2 hours of stroke onset.
• Enrollment proportions: 0-60 min (0.2%), 61-120 min (1.2%), 121-180 min (6.3%), 181-360 min (69.7%).

Conclusions:

• A very small fraction of patients in recent stroke trials are enrolled within the crucial hyperacute (<3-hour) period.
• Delayed enrollment hinders the potential efficacy of neuroprotective agents.
• Novel trial designs and treatment delivery strategies are needed to expedite agent initiation.