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An issue in drug discovery research at pharmaceutical companies is the decline in the probability of market launch, and there is a need to improve the proof-of-concept (POC) acquisition rate by further improving clinical predictability. For this purpose, we need to deepen our understanding of human pathophysiology, and to make efficient of drug discovery research by utilizing human samples and data due to the change in mindset from "animals" to "humans" at the drug discovery research stage. In particular, with the aim of improving the efficiency of drug discovery research by utilizing human samples/data, we have established a human sample utilization support capability, then we are supporting the acquisition of appropriate human samples/data to meet each drug research need with collecting information on organizations that can provide various human samples and accumulating know-how on obtaining human samples/data. In addition, we have built a one-stop support system for surveying human samples/data, negotiating, and contracting with the organizations, obtaining ethical committee approvals, importing samples, and dealing with customs clearance. As results, our researchers can obtain high-quality human samples/data to meet their research needs rapidly/easily. By establishing this capability, the number of the research projects that implement target validation, pharmacological evaluation, BM identification, and patient stratification, etc. using human samples/data from the early stage of drug discovery, has increased, and then, the evidence obtained by using human samples/data contribute to create drug candidates with high probability of clinical effect. We will introduce our activities while showing the support flow that was actually constructed.

Platelet activation and subsequent aggregation play a key role in the pathogenesis of ischemic brain damage. Recent studies revealed that enhanced platelet activation is also observed after ischemia, suggesting that secondary thrombus formation might participate in the development of cerebral infarction. The binding of platelet glycoprotein GPIIb/IIIa (integrin alpha(IIb)beta3) to fibrinogen is the final common pathway in platelet aggregation. Therefore, GPIIb/IIIa antagonists might be useful in acute ischemic stroke as well as in the secondary prevention of ischemic stroke. In the present study, we evaluated the effect of three compounds, FK419 ((S)-2-acetylamino-3-[(R)-[1-[3-(piperidin-4-yl) propionyl] piperidin-3-ylcarbonyl] amino] propionic acid trihydrate), a novel nonpeptide GPIIb/IIIa antagonist, ozagrel, a selective thromboxane A(2) synthase inhibitor, and argatroban, a thrombin inhibitor, on middle cerebral artery (MCA) patency and ischemic brain damage using photochemically induced MCA thrombosis model in guinea pigs. FK419, ozagrel, or argatroban was administered 5 min after the termination of photoirradiation. FK419 dose-dependently improved MCA patency by decreasing the total occlusion time, time to continuous reperfusion, and the number of cyclic flow reductions, at doses that inhibited ADP-induced platelet aggregation ex vivo. In contrast, ozagrel only improved total occlusion time, and argatroban showed no improvement in MCA patency. FK419 also reduced ischemic brain damage in a dose-dependent fashion, whereas ozagrel and argatroban did not. Finally, FK419 ameliorated neurological deficits, whereas ozagrel and argatroban did not. These results indicate that FK419, a GPIIb/IIIa antagonist, ameliorates ischemic brain damage by improving MCA patency after occlusion and that FK419 is a promising candidate for the treatment of acute ischemic stroke.