A potent new inhibitor of platelet aggregation and experimental thrombosis, anagrelide (BL-4162A)

Abstract

Anagrelide, 6,7-dichloro-1,5-dihydroimidazo[2,1-b]quinazolin-2(3H)-one monohydrochloride (BL-4162A), is a potent inhibitor of platelet aggregation induced by a variety of aggregating agents in platelet rich plasma obtained from various species including man (EC50 s < 1 μg/ml). This potent activity carried over to the ex vivo situation following oral dosing as demonstrated in rats, dogs and rhesus monkeys. BL-4162A effectively inhibited experimental thrombosis and platelet aggregability in a series of in vivo animal models following oral doses in the range of 0.2–10 mg/kg. Results indicate that BL-4162A possesses important quantitative and qualitative differences from currently available antithrombotic agents and may represent a unique, new entry into this therapeutic class of drugs.