Preclinical and Clinical Studies with Selective Reversible Direct P2Y₁₂ Antagonists

ABSTRACT

An important role for adenosine diphosphate (ADP)-induced platelet activation and aggregation was proposed more than 40 years ago. The clinical use of clopidogrel, a prodrug of an irreversible P2Y₁₂ antagonist, has further proved the relevance of inhibiting signaling via the platelet-specific P2Y₁₂ ADP receptor in the prevention of cardiovascular events. Pharmacological studies at AstraZeneca R&D Charnwood have identified direct, selective, and competitive P2Y₁₂ antagonists, including cangrelor (also known as AR-C69931MX), which is suitable for intravenous administration, and AZD6140, which is suitable for oral administration. In preclinical use, these compounds predictably and effectively inhibited platelet aggregation without significant increases in bleeding time. In clinical use, these compounds may have significant advantages over current antiplatelet agents. This article summarizes preclinical and clinical data on cangrelor and AZD6140 and discusses the potential of these compounds as novel antiplatelet therapies.

AR-C69931MX - AZD6140 - P2Y₁₂ receptor - platelets - platelet antagonists

REFERENCES

• 1 Gaarder A, Jonson J, Laland S, Lellem A, Owren P. Adenosine diphosphate in red cells as a factor in the adhesiveness of human platelets.  Nature. 1961;  192 531-532
• 2 Burnstock G, King B. Numbering of cloned P2 receptors.  Drug Dev Res. 1996;  38 67-71
• 3 Fagura M S, Dainty I A, McKay G D et al.. P2Y₁-receptors in human platelets which are pharmacologically distinct from P2YADP-receptors.  Br J Pharmacol. 1998;  124 157-164
• 4 Hollopeter G, Jantzen H M, Vincent D et al.. Identification of the platelet ADP receptor targeted by antithrombotic drugs.  Nature. 2001;  409 202-207
• 5 McFarlane D, Mills D. The effect of ATP on platelets: evidence against the central role of released ADP in primary aggregation.  Blood. 1975;  46 309-320
• 6 Gordon J. Extracellular ATP: effects, sources and fate.  Biochem J. 1986;  233 309-319
• 7 Cusack N, Hourani S. Adenosine 5′-diphosphate antagonists and human platelets: no evidence that that aggregation and inhibition of stimulated adenylate cyclase are mediated by different receptors.  Br J Pharmacol. 1982;  76 221-227
• 8 Cusack N, Hourani S. Specific but noncompetitive inhibition by 2-alkylthio analogues of adenosine 5′-monophosphate and adenosine 5′-triphosphate of human platelet aggregation induced by adenosine 5′-diphosphate.  Br J Pharmacol. 1982;  75 397-400
• 9 Welford L, Cusack N, Hourani S. ATP analogues and the guinea-pig Taenia coli : a comparison of the structure-activity relationships of ectonucleotidases with those of the P2-purinoceptor.  Eur J Pharmacol. 1986;  129 217-224
• 10 Humphries R G, Tomlinson W, Ingall A H, Cage P A, Leff P. FPL 66096: a novel, highly potent and selective antagonist at human platelet P2T-purinoceptors.  Br J Pharmacol. 1994;  113 1057-1063
• 11 Humphries R G, Tomlinson W, Clegg J A et al.. Pharmacological profile of the novel P2T-purinoceptor antagonist, FPL 67085 in vitro and in the anaesthetized rat in vivo.  Br J Pharmacol. 1995;  115 1110-1116
• 12 Ingall A H, Dixon J, Bailey A et al.. Antagonists of the platelet P2T receptor: a novel approach to antithrombotic therapy.  J Med Chem. 1999;  42 213-220
• 13 Communi D, Robaye B, Boeynaems J M. Pharmacological characterization of the human P2Y₁₁ receptor.  Br J Pharmacol. 1999;  128 1199-1206
• 14 Marteau F, Le Poul E, Communi D et al.. Pharmacological characterization of the human P2Y₁₃ receptor.  Mol Pharmacol. 2003;  64 104-112
• 15 Storey R F, Oldroyd K G, Wilcox R G. Open multicentre study of the P2T receptor antagonist AR-C69931MX assessing safety, tolerability and activity in patients with acute coronary syndromes.  Thromb Haemost. 2001;  85 401-407
• 16 Fox S, Burgess-Wilson M, Heptinstall S, Mitchell J. Platelet aggregation in whole blood determined using the Ultra-Flow 100 platelet counter.  Thromb Haemost. 1982;  48 327-329
• 17 Tomlinson W, Cusworth E A, Midha A et al.. Characterization of the P2T receptor antagonist properties of AR-C69931MX in human washed platelets in vitro.  Haematologica. 2000;  85 95-96 , (abst)
• 18 Maayani S, Tagliente T M, Schwarz T et al.. The balance of concurrent aggregation and deaggregation processes in platelets is linked to differential occupancy of ADP receptor subtypes.  Platelets. 2001;  12 83-93
• 19 Lova P, Paganini S, Hirsch E et al.. A selective role for phosphatidylinositol 3,4,5-trisphosphate in the Gi-dependent activation of platelet Rap1B.  J Biol Chem. 2003;  278 131-138
• 20 Lova P, Paganini S, Sinigaglia F, Balduini C, Torti M. A Gi-dependent pathway is required for activation of the small GTPase Rap1B in human platelets.  J Biol Chem. 2002;  277 12009-12015
• 21 Jin J, Tomlinson W, Kirk I P et al.. The C6-2B glioma cell P2YAC receptor is pharmacologically and molecularly identical to the platelet P2Y12 receptor.  Br J Pharmacol. 2001;  133 521-528
• 22 Jagroop I A, Burnstock G, Mikhailidis D P. Both the ADP receptors P2Y1 and P2Y₁₂, play a role in controlling shape change in human platelets.  Platelets. 2003;  14 15-20
• 23 Goto S, Tamura N, Eto K, Ikeda Y, Handa S. Functional significance of adenosine 5′-diphosphate receptor (P2Y(12)) in platelet activation initiated by binding of von Willebrand factor to platelet GP Ibalpha induced by conditions of high shear rate.  Circulation. 2002;  105 2531-2536
• 24 Nylander S, Mattsson C, Ramstrom S, Lindahl T. The relative importance of the ADP receptors, P2Y₁₂ and P2Y₁, in thrombin-induced platelet activation.  Thromb Res. 2003;  111 65-73
• 25 Jung S M, Moroi M. Platelet collagen receptor integrin alpha2beta1 activation involves differential participation of ADP-receptor subtypes P2Y1 and P2Y12 but not intracellular calcium change.  Eur J Biochem. 2001;  268 3513-3522
• 26 Ishii-Watabe A, Uchida E, Mizuguchi H, Hayakawa T. On the mechanism of plasmin-induced platelet aggregation. Implications of the dual role of granule ADP.  Biochem Pharmacol. 2000;  59 1345-1355
• 27 Leff P, Robertson M J, Humphries R G. The role of ADP in thrombosis and the therapeutic potential of P2T-receptor antagonists as novel antithrombotic agents. In: Jacobson A, Jarvis MF Purinergic Approaches in Experimental Therapeutics New York; Wiley-Liss 1997: 203-216
• 28 Humphries R G, Nicol A K, Tomlinson W et al.. Effect of the novel P2T receptor antagonist, AR-C69931MX, on thrombosis and haemostasis in the dog: comparison with GPIIb/IIIa antagonists.  Haematologica. 2000;  85 91-92 , (abst)
• 29 Huang J, Driscoll E M, Gonzales M L, Park A M, Lucchesi B R. Prevention of arterial thrombosis by intravenously administered platelet P2T receptor antagonist AR-C69931MX in a canine model1.  J Pharmacol Exp Ther. 2000;  295 492-499
• 30 van Gestel M A, Heemskerk J W, Slaaf D W et al.. In vivo blockade of platelet ADP receptor P2Y12 reduces embolus and thrombus formation but not thrombus stability.  Arterioscler Thromb Vasc Biol. 2003;  23 518-523
• 31 Wang K, Zhou X, Zhou Z et al.. Blockade of the platelet P2Y₁₂ receptor by AR-C69931MX sustains coronary artery recanalization and improves the myocardial tissue perfusion in a canine thrombosis model.  Arterioscler Thromb Vasc Biol. 2003;  23 357-362
• 32 Nurden A T, Nurden P. Advantages of fast-acting ADP receptor blockade in ischemic heart disease.  Arterioscler Thromb Vasc Biol. 2003;  23 158-159
• 33 Storey R F. Clinical experience with antithrombotic drugs acting on purine receptor pathways.  Drug Dev Res. 2001;  52 202-212
• 34 Nassim M A, Sanderson J B, Clarke C et al.. Investigation of the novel P2T receptor antagonist AR-C69931MX on ex vivo adenosine diphosphate-induced platelet aggregation and bleeding time in healthy volunteers.  J Am Coll Cardiol. 1999;  33 225 , (abst)
• 35 Rao A K, Pratt C, Berke A et al.. Thrombolysis in myocardial infarction (TIMI) trial-phase I: hemorrhagic manifestations and changes in plasma fibrinogen and the fibrinolytic system in patients treated with recombinant tissue plasminogen activator and streptokinase.  J Am Coll Cardiol. 1988;  11 1-11
• 36 Jacobsson F, Swahn E, Wallentin L, Ellborg M. Safety profile and tolerability of intravenous AR-C69931MX, a new antiplatelet drug, in unstable angina pectoris and non-Q-wave myocardial infarction.  Clin Ther. 2002;  24 752-765
• 37 Weaver W D, Becker R, Harrington R A et al.. Safety and efficacy of a novel direct P2T platelet receptor antagonist, AR-C69931MX, in patients undergoing percutaneous coronary intervention.  Eur Heart J. 2000;  21 382 , (abst)
• 38 Greenbaum A, Ohman E, Gibson M et al.. Intravenous adenosine diphosphate P2T platelet receptor antagonism as an adjunct to fibrinolysis for acute myocardial infarction.  J Am Coll Cardiol. 2002;  39 281A , (abst)
• 39 Gurbel P A, Bliden K P, Hiatt B L, O'Connor C M. Clopidogrel for coronary stenting: response variability, drug resistance, and the effect of pretreatment platelet reactivity.  Circulation. 2003;  107 2908-2913
• 40 Jaremo P, Lundahl T L, Fransson S G, Richter A. Individual variations of platelet inhibition after loading doses of clopidogrel.  J Intern Med. 2002;  252 233-238
• 41 Muller I, Besta F, Schulz C et al.. Prevalence of clopidogrel non-responders among patients with stable angina pectoris scheduled for elective coronary stent placement.  Thromb Haemost. 2003;  89 783-787
• 42 Gurbel P A, Bliden K P. A new method of representing drug-induced platelet inhibition: better description of time course, response variability, non-response, and heightened reactivity.  Platelets. 2003;  14 481-483
• 43 Gurbel P A, Bliden K P. Durability of platelet inhibition by clopidogrel.  Am J Cardiol. 2003;  91 1123-1125
• 44 Lau W C, Gurbel P A, Watkins P B et al.. Contribution of hepatic cytochrome P450 3A4 metabolic activity to the phenomenon of clopidogrel resistance.  Circulation. 2004;  109 166-171
• 45 Lau W C, Waskell L A, Watkins P B et al.. Atorvastatin reduces the ability of clopidogrel to inhibit platelet aggregation-a new drug-drug interaction.  Circulation. 2003;  107 32-37
• 46 Neubauer H, Gunesdogan B, Hanefeld C, Spiecker M, Mugge A. Lipophilic statins interfere with the inhibitory effects of clopidogrel on platelet function - a flow cytometry study.  Eur Heart J. 2003;  24 1744-1749
• 47 Muller I, Besta F, Schulz C et al.. Effects of statins on platelet inhibition by a high loading dose of clopidogrel.  Circulation. 2003;  108 2195-2197
• 48 Jarvis G E, Nassim M A, Humphries R G et al.. Clopidogrel produces incomplete inhibition of [33P]-2MeSADP binding to human platelets and less inhibition of ADP-induced platelet aggregation than the P2T antagonist AR-C69931MX.  Haematologica. 2000;  85 92-93 , (abst)
• 49 Storey R F, Wilcox R G, Heptinstall S. Comparison of the pharmacodynamic effects of the platelet ADP receptor antagonists clopidogrel and AR-C69931MX in patients with ischaemic heart disease.  Platelets. 2002;  13 407-413(abs)
• 50 Beham M W, Fox S, Sanderson H, Storey R, Heptinstall S. Effect of clopidogrel on procoagulant activity in acute coronary syndromes: evidence for incomplete P2Y₁₂ receptor blockade.  Circulation. 2002;  106 II-149-II-150 , (abst)
• 51 Humphries R G. Pharmacology of AR-C69931MX and related compounds: from pharmacological tools to clinical trials.  Haematologica. 2000;  85 66-72