Abstract W P97: A Single Intravenous Dose of the Pyrazole CNB-001 Induces Long Term Behavioral Improvement and Reduces Stroke Volume in a Rat Ischemic Stroke Model

Abstract

Future stroke therapy will require pleiotropic drugs with multi-mechanisms of action. We studied a safe pyrazole compound, CNB-001, which has multiple potent neuroprotective and neurotrophic activities. Previously, we found that CNB-001 improves clinical function following small clot embolic stroke in rabbits, increase cortical brain-derived neurotrophic factor (BDNF) content and activates BDNF signaling pathways. Abiding by RIGOR guidelines (blinding and randomization), we studied CNB-001 in rat stroke model [filament middle cerebral artery occlusion (MCAo)] where Sprague-Dawley (SD) rats were subjected to 3 hours MCAo. After a delay of 1 hour during reperfusion, CNB-001 (10 mg/kg) or vehicle (n=12 per group) was infused through the jugular vein over 5 mins as a single dose. One week after stroke onset, these animals were tested using a cylinder test, a measure of limb-use-asymmetry, and further cylinders tests were done at week 2 and 4 following stroke, and then followed by Barnes Maze analysis, to quantitate spatial learning and memory. CNB-001-treated rats showed significant improvement (p<0.05, ANOVA with Tukey’s) in limb use asymmetries compared to control at week 1, 2 and week 4, and learning and memory (learning curve and latency time) using Barnes maze (p<0.05). Additional SD rats were subjected to MCAo varying duration between 5 and 80 minutes in order to construct a quantal analysis curve to calculate a P 50 value (minutes), which represents the occlusion time required to induce behavioral deficits in 50% of the population. IV CNB-001 treatment administered 5 minutes following the end of occlusion, significantly (p<0.05, t-test) reduced stroke-induced behavioral deficits (improved function) and increased the P 50 value to P 50 = 46.71±7.58 minutes (n=21) compared with the control group (P 50 = 24.9±6.07 minutes, n=20). Moreover, CNB-001 significantly reduced infarct volume by 60-95%(p<0.05) independent of occlusion duration, confirming its neuroprotective activity. We show that a single IV treatment with CNB-001 effectively improves cognition and motor skills in MCAo rats, and also reduces infarct volume. CNB-001 should be further tested in a blinded fully randomized stroke clinical trial.