Analysis of early phase and subsequent phase III stroke studies of neuroprotectants: outcomes and predictors for success.

Background Efficacy of neuroprotective treatments for ischemic stroke was not convincingly demonstrated in clinical phase III trials so far, whereas some preceding early phase studies found neuroprotection to be beneficial. We aimed to determine the frequency with which phase III studies are preceded by positive early phase studies, and to identify characteristics of early phase studies that are associated with correct prediction of phase III studies.