Atopaxar (hydrochloride)

Atopaxar hydrochloride (E5555 hydrochloride) is the hydrochloride salt form of Atopaxar (HY-18200). Atopaxar hydrochloride is an orally active, selective and reversible antagonist for thrombin receptor protease-activated receptor-1 (PAR-1). Atopaxar hydrochloride is the inhibitor for Janus kinase 1 (JAK1) and JAK2, which inhibits the JAK-STAT with EC50 of 5.90 μM in A549. Atopaxar hydrochloride inhibits the cell viability of A549 (IC50=7.02 μM), arrests the cell cycle at G1 phase and induces apoptosis. Atopaxar hydrochloride exhibits antiplatelet and antitumor activities. Atopaxar hydrochloride can be used for the research of atherothrombotic disease[1][2][3].

[1]Motoji Kogushi, et al. The novel and orally active thrombin receptor antagonist E5555 (Atopaxar) inhibits arterial thrombosis without affecting bleeding time in guinea pigs. Eur J Pharmacol. 2011 Apr 25;657(1-3):131-7.|[2]Chris Dockendorff, et al. Discovery of 1,3-Diaminobenzenes as Selective Inhibitors of Platelet Activation at the PAR1 Receptor. ACS Med Chem Lett. 2012 Mar 8; 3(3): 232–237.|[3]Sun J, et al., Discovery and evaluation of Atopaxar hydrobromide, a novel JAK1 and JAK2 inhibitor, selectively induces apoptosis of cancer cells with constitutively activated STAT3. Invest New Drugs. 2020 Aug;38(4):1003-1011.