Abstract TP311: Preclinical Replication Study of Psd-95 Inhibitor NA-1

Abstract

Background & Objective: Nerinate (NA-1), a postsynaptic density protein-95 inhibitor, is a clinical-stage stroke neuroprotectant. Recently, in a phase-III clinical trial (Efficacy and safety of nerinetide for the treatment of acute ischaemic stroke [ESCAPE-NA1]), a single intravenous dose of NA-1 did not improve the proportion of patients achieving favorable 3-month functional outcomes after endovascular thrombectomy compared with patients receiving placebo. Thus, we conducted a preclinical replication study to test therapeutic efficacy of NA-1 in a mouse model of transient middle cerebral artery occlusion (tMCAO). Methods: After 30-minute or 60-minute MCAO with laser Doppler flowmetry (LDF) monitoring, mice were randomly assigned to a group treated with either vehicle control (n=10 and 21, respectively) or 10 nM/g NA-1 (n=10 and 21, respectively), which was intravenously administered once via penile vein in a volume of 200 μL at the beginning of recanalization. In a different set of mice (n=6 for vehicle and n=6 for NA-1), we performed MCAO and then allowed animals to wake up before reperfusion at 60 minutes to account for continuous anesthesia-related confounding. At 1-day poststroke, brain was harvested and sliced in 2-mm thickness for 2,3,5-triphenyl-tetrazolium chloride (TTC) staining and infarct volume measurement after neurological scoring. Results: LDF data indicated that stroke modeling was executed proficiently, without inter-group differences. The vehicle group and the NA-1 group showed similar infarct volumes at 1 day after either 30 minutes (32.5±6.4 mm 3 and 44.7±8.7 mm 3 ; t-test P =0.27) or 60 minutes of MCAO (113.4±7.6 mm 3 and 108.2±7.6 mm 3 ; P =0.63). Awakening between occlusion and reperfusion did not change the negative Results: 109.4±11.7 mm 3 and 115.8±10.6 mm 3 ( P =0.69). Neurological scores did not show significant inter-group differences, either (all P >0.05). Conclusions: We were unable to reproduce neuroprotective effects of NA-1 to reduce infarct volume at 1 day after tMCAO for 30 or 60 minutes. We suggest that implementation of multicenter animal studies is warranted to enhance the reproducibility and generalizability of preclinical observations.