DX-9065a, a New Synthetic, Potent Anticoagulant and Selective Inhibitor for Factor Xa

Summary

DX-9065a is an orally active newly synthesized and specific inhibitor for factor Xa. We have examined the property of DX-9065a in vitro and ex vivo. DX-9065a prolonged human plasma recalcification time, APTT and PT. Its doubling concentrations for clotting times of each coagulation assay were 0.49, 0.97 and 0.52 μM, respectively. Kinetic study revealed that DX-9065a inhibited competitively human factor Xa (Ki value: 41 μM). Ki values (pM) for other human serine proteases were as follows; thrombin >2000, trypsin 0.62, chymotrypsin >2000, plasmin 23, t-PA 21, plasma kallikrein 2.3 and tissue kallikrein 1000. DX-9065a up to 100 μM had no effects on human platelet aggregation. After intravenous or oral administration, DX-9065a significantly prolonged APTT and PT with a dose dependent manner. These effects were well correlated with anti-Xa activity in plasma. These results suggest that DX-9065a may become an anticoagulant by means of the specific inhibition of factor Xa.

• References

• 1 Sixma JJ, Groot PGde. The ideal anti-thrombotic drug. Thromb Res 1992; 68: 507-12
• 2 Bagdy D, Barabas E, Szabo G, Bajusz S, Szell E. In vivo anticoagulant and antiplatelet effect of D-Phe-Pro-Arg-H and D-Me-Phe-Pro-Arg-H. Thromb Haemostas 1992; 67: 357-65
• 3 Okamoto S, Hijikata A, Kikumoto R, Tonomura S, Kara H, Ninomiya K, Maruyama A, Sugano M, Tamao Y. Potent inhibition of thrombin by the newly synthesized arginine derivative No. 805. The importance of stereostructure of its hydrophobic carboxamide portion. Biochem Biophys Res Commun 1981; 101: 440-6
• 4 Pâques EP, Romisch J. Comparative study on the in vitro effectiveness of antithrombotic agents. Thromb Res 1991; 64: 11-21
• 5 Kumada T, Abiko Y. Comparative study on heparin and a synthetic thrombin inhibitor No. 805 (MD-805) in experimental antithrombin Ill-deficient animals. Thromb Res 1981; 24: 285-98
• 6 Morishita K, Wada M, Kumada T, Tanaka T, Tomikawa M, Iwamoto M. Effect of ticlopidine and other antithrombotics on the venous thrombosis induced by endothelial damage of jugular vein in rats. Thromb Res 1991; 63: 373-84
• 7 Kelly AB, Maraganore JM, Bourdon P, Hanson SR, Harker LA. Antithrombotic effects of synthetic peptides targeting various functional domains of thrombin. Proc Natl Acad Sci 1992; 89: 6040-4
• 8 Gruber A, Griffin JH, Harkar LA, Hanson SR. Inhibition of platelet dependent thrombus formation by human activated protein C in a primate model. Blood 1989; 73: 639-42
• 9 Gruber A, Hanson SR, Kelly AB, Yan BS, Bang N, Griffin JH, Harker LA. Inhibition of thrombus formation by activated recombinant protein C in a primate model of arterial thrombosis. Circulation 1990; 82: 578-85
• 10 Kane WH, Davie EW. Blood coagulation factors V and VIII: Structural and functional similarities and their relationship to hemorrhagic and thrombotic disorders. Blood 1988; 71: 539-55
• 11 Marlar RA, Kleiss AJ, Griffin JH. Mechanism of action of human activated protein C, a thrombin-dependent anticoagulant enzyme. Blood 1982; 59: 1067-72
• 12 Gruber A, Harker LA, Hanson SR, Kelly AB, Griffin JH. Antithrombotic effects of combining activated protein C and urokinase in nonhuman primates. Circulation 1991; 84: 2554-62
• 13 Jordan SP, Mao SS, Lewis SD, Shafer JA. Reaction pathway for inhibition of blood coagulation factor Xa by tick anticoagulant peptide. Biochemistry 1992; 31: 5374-80
• 14 Dunwiddie CT, Thomberry NA, Bull HG, Sardana M, Friedman PA, Jacobs JW, Simpson E. Antistasin a leech derived inhibitor of factor Xa. Kinetic analysis of enzyme inhibition and identification of the reactive site. J Biol Chem 1989; 264: 16694-9
• 15 Sitko GR, Ramjit DR, Stabilito II, Lehman D, Lynch JJ, Vlasuk GP. Conjunctive enhancement of enzymatic thrombolysis and prevention of thrombotic reocclusion with the selective factor Xa inhibitor, tick anticoagulant peptide: Comparison to hirudin and heparin in a canine model of acute coronary artery thrombosis. Circulation 1992; 85: 805-15
• 16 Kraut J. Serine proteases: Structure and mechanism of catalysis. Annu Rev Biochem 1977; 46: 331-58
• 17 Tidwell RR, Webster WP, Shaver SR, Geratz JD. Strategies for anticoagulation with synthetic protease inhibitors. Xa inhibitors versus thrombin inhibitors. Thromb Res 1980; 19: 339-49
• 18 Leytus SP, Chung DW, Kisiel W, Kurachi K, Davie EW. Characterization of a cDNA coding for human factor X. Proc Natl Acad Sci USA 1984; 81: 3699-702
• 19 Friezner Degan SJ, MacGillivray RTA, Davie EW. Characterization of the complementary deoxyribonucleic acid and gene coding for human prothrombin. Biochemistry 1983; 22: 2087-97
• 20 Jordan SP, Waxman L, Smith DE, Vlasuk GP. Tick anticoagulant peptide: kinetic analysis of the recombinant inhibitor with blood coagulation factor Xa. Biochemistry 1990; 29: 11095-100
• 21 Dunwiddie CT, Smith DE, Nutt EM, Vlasuk GP. Anticoagulant effects of the selective factor Xa inhibitors tick anticoagulant peptide and antistasin in the APTT assay are determined by the relative rate of prothrombinase inhibition. Thromb Res 1991; 64: 787-94
• 22 Elódi S, Varadi K. Optimization of conditions for the catalytic effect of the factor IXa-factor VIII complex: Probable role of the complex in the amplification of blood coagulation. Thromb Res 1979; 15: 617-29
• 23 Waxman L, Smith D, Arcuri KE, Vlasuk GP. Tick anticoagulant peptide (TAP) is a novel inhibitor of blood coagulation factor Xa. Science 1990; 248: 593-6
• 24 Kelly AB, Hanson SR, Dunwiddie CT, Harker LA. Safe lasting interruption of arterial thrombosis by transient intravenous administration of tick anticoagulant peptide (TAP). Circulation 1992; 86: 1411
• 25 Jackson CV, Crowe G, Frank JD, Wilson HC, Coffman WJ, Utterback BG, Jakubowski JA, Smith GF. Pharmacological assessment of antithrombotic activity of the peptide thrombin inhibitor, D-methyl-phenylalanyl-prolvlarginal (GYKI-14766), in a canine model of coronary artery thrombosis. J Pharmacol Exp Ther 1992; 261: 546-52
• 26 Berndt MC, Gregory C, Dowden G, Castaldi PA. Thrombin interaction with platelet membrane proteins. Ann NY Acad Sci 1986 485: 374-86
• 27 Higgins DL, Lewis SD, Shafer JA. Steady state kinetic parameters for the thrombin catalyzed conversion of human fibrinogen to fibrin. J Biol Chem 1983; 258: 9276-82