A thrombocytaaggregáció

Átírás

1 A thrombocytaaggregáció aggregáció-, és gátlásának elméleti és néhány gyakorlati aspektusa: néhány újdonság MAÉT Kongresszus, Szombathely Dr. Blaskó György 2017

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4 Adhesion inhibitors. ARC-1779 is an optimized, second-generation, PEGylated aptamer that exerts a novel antithrombotic action through targeting the A1 domain of activated vwf and inhibiting the binding of platelet receptor glycoprotein Ib. It thus reduces platelet adhesion, and aggregation and thereby thrombus formation in arterial beds Aurin tricarboxylic acid: heterogenous mixture of polycarboxylic acid and polyaromatic polymers: prevents the binding of vwf multimers to GPIb. VCL peptides: a peptide fragment originating from vwf from Leu 504 tolys728 containing10 % sequenceof vwf.: inhibitsplateet adhesion and prevents arterial thrombosis in animal experiments.

5 Antithrombocyta szerek: Az adhaesio inhibitorai:von Willebrand faktor gátlók: A vwf kötődésének gátlás a GPIb-hez A GPIb kötőhelyek gátlása A vwf multimerizáció gátlása Pl. aurin tricarboxilsav, peptid fragmentek, amik a vwf-gpib-gpix kötő doménekből származnak,monoclonalis antitestek vwf ellen, stb. Az aggregáció gátlók ( GP IIb/IIIa gátlók) Monoclonalis antitestek: pl. Abciximab(ReoPro) Szintetikus peptidek: iv adhatók: tirofiban, Eptifibatide lamifiban I. generatios szerek: xemilofiban, Sibrafiban,Orbofiban, Lotrafiban II. generatios oralis szerek: roxifiban, cromofiban(gr-83895, SHF , MK-852, DMP-728, BIBU-104, GR , L fejlesztés alatt) Kigyómérgek:barbourin, echistatin, kistrin, albolabrin,triflavin, applaggin, elegantin, eristicophin, decorsin, stb. GP VI antagonsiták: kistomin és a revacept PIP3K inhibitorok: TGX 221 GP Ib inhibitorok: 6B4Fab mab A thrombocyta aktiváció gátlói: A cyclooxygenase út gátlói: Cyclooxygenase inhibitorok: aspirin, NSAID-ok számosan, Indobufen, Triflusal Thromboxan synthetase gátlók: dazoxiben Thromboxan receptor antagonisták campregulátorok: Adenyl cyclase aktivátorok: prostacyclin, Beraprost, Cicaprost, Taprostene Phosphodiesterase gátlók: dipyridamole, Pentoxifyllin, Cilostazol, Trapidil A thrombin-mediált aktiváció gátlása: Thrombin inhibitorok: dabigatran Thrombin receptor antagonisták: vorapaxar, atopaxar Serotonin gátlók: ketanserin, 5HT2A antagonisták ADP-mediált aktiváció gátlása: P2Y12 blokkolók: ticlopidin, Clopidogrel Nem osztályozható hatású anyagok: Több hatásmechanizmussal gátlók: ditazole, Anagrelide Egyéb:buflomedil, lexipafant, nafazatrom, carbocromen,cloricromene, ronicol, vasopressin blokkolók, PAF-antag. Secunder thrombocyta gátlók: heparin, nitrátok, NO, fibrátok, Ca-csatorna blokkolók, ω-3-zsirsavak, stb.

6 Resistance to Antiplatelet Therapy: Potential Mechanisms Clinical: Smoking, diabetes, ACS Genetic: Polymorphisms (receptor, metabolism) Dose: Inadequate blood level Drug interaction: NSAID-ASA Statin-clopidogrel Platelet biology: Number of platelets Multiple agonists for activation Alternative sites of biomediator generation

7 De Gaetano G., Cerletti C.: Possible mechanisms of aspirin resistance Bioavailability of aspirin: 1. non-compliance 2. insufficient aspirin dosage 3. accumulation of salicylate, preventing the access of ASA to COX-2 4. Concurrent intake of short-lasting NSAID, preventing the long-lasting effect of ASA and of proton pump inhibitors, reducing bioavail. Platelet function: 5. Accelerated platelet turnover, introducing into blood stream newly formed, non-aspirinated platelets 6. variable expression of COX-2 in (newly formed) platelets 7. increased sensitivity to ADP and collagen Polymorphism: 8. of platelet collagen receptor 9. of COX-1, COX-2, TXA2 synthase or other arachidonate metabolism enzymes 10 of GPIIb/IIIa receptor 11 of F XIII Val34Leu, leading to variable inhibition of XIII activation by low-dose aspirin

8 De Gaetano G., Cerletti C.: Possible mechanisms of aspirin resistance 2. Platelet interactions with other blood cells and cell-derived products 12. Inadequate blockade of red cell-induced platelet activation 13. Transcellular arachidonate metabolism between aspirinated platelets and vascular cells. 14. Monocyte-macrophag-derived TXA2 15. COX-1/COX-2-catalyzed vascular PGI2 as regulator of TXA2 or vascular tissue plasminogen activator (t-pa) release Other factors: 16. Increased levels of norepinephrine (excessive physical exercise, mental stress) 17. smoking 18. Oxidant stress and biosynthesis of 8-iso-PGF2a, a bioactive product of arachidonate non-enzymatic peroxidation 19. interaction of aspirin with acetylcholine-mediated nitric oxide antiplatelet and vasodilatory effect

9 Mit adhatunk az ASA-rezisztens ill. non-responzív betegnek? Laboratóriumi non-responsio Klinikai non-responsio?

10 Thienopyridineket! Clopidogrel: nagy klinikai vizsgálatok: CAPRIE, MATCH, stb Évi 6 milliárd $

11 Chemical structures of the P2Y12 inhibitors. Wallentin L Eur Heart J 2009;30: Published on behalf of the European Society of Cardiology. All rights reserved. The Author For permissions please journals.permissions@oxfordjournals.org

12 Mit adjunk, ha a beteg bizonyítottan ASA-nonresponsív és thienopyridine-rezisztens? Vorapaxart, Cilostazolt esetleg a serotoninreceptoron ható anyagok Pl. ketanserin Hátránya: nincs rá evidencia (EBM trials

13 Egységes definició Resistant Platelets: Mit lehet tenni? A laborvizsgálatok javulása (POC) Correlation of laboratory assays with clinical events Új therápiás strategiák kidolgozása A jövőben individualizált therápia (pharmacogenomics)

14 State of the Art Management of non-st ACS Acute ASA + Clopidogrel LMWH/UFH IV GP IIb/IIIa inhibitor during PCI for those undergoing an invasive strategy (moderate to high risk patients) Long Term ASA + Clopidogrel for at least one year Planned program of secondary risk factor modification including smoking cessation, lipid lowering therapy, ACE inhibitor, BP and diabetic control, weight reduction

15 Orális készítmények

16 Eur Heart J Jan;29(1): Epub 2007 Nov 30. Prasugrelachievesgreaterand fasterp2y12receptor-mediated plateletinhibitionthanclopidogrelduetomore efficient generation of its active metabolite in aspirin-treated patients with coronary artery disease. Wallentin L, Varenhorst C, James S, Erlinge D, Braun OO, Jakubowski JA, Sugidachi A, Winters KJ, Siegbahn A. Methods: One hundred and ten aspirin treated subjects were randomized to double-blind treatmentwithclopidogrel(n = 55), 600 mg loadingdose(ld) and 75 mg maintenancedose (MD) orprasugrel(n = 55) 60 mg LD and 10 mg MD for28 days. Concentrations of prasugrel and clopidogrel active metabolites were determined. CONCLUSION: Inaspirin-treatedsubjectswithcoronaryarterydisease, prasugrel60/10 mg provides faster onset and greater inhibition of P2Y(12) receptor-mediated platelet aggregation than clopidogrel 600/75 mg, because of greater and more efficient generation of the active metabolite.

17 Tricagrelor New class of P2Y 12 inhibitor (CPTP: cyclopentyl-triazolopyrimidine) Direct acting (non-prodrug) Rapid onset (<1 h) of effect Dose-dependent IPA > clopidogrel 20µM ADP: AZD 60-75%; clopidogrel 35-40% No nonresponders at higher bid doses Reversible (T ½ = 12 h) BRILIQUE (Ticagrelor) is a direct-acting P2Y12 receptor antagonist in a chemical class called cyclo-pentyl-triazolo-pyrimidines(cptps). Ticagrelor is the first reversiblybinding oral ADP receptor antagonist. BRILIQUE, a prescription oral antiplatelet treatment, co-administered with acetylsalicylic acid(asa), is indicated for the prevention of atherothrombotic events in adult patients with Acute Coronary Syndromes(unstable angina, NSTEMI, or STEMI), including patients managed medically and those who are managed with percutaneous coronary intervention(pci) or Coronary Artery Bypass Grafting (CABG). HO O HO N N N OH HN N N S F F

18 TRICAGRELOR Efficacy and Safety of Ticagrelor: A Reversible P2Y12 Receptor Antagonist by Anderson SD, ShahNK, YimJ, EpsteinBJ. AnnPharmacother.2010 Feb2. Tricagrelor selectively and reversibly blocks the P2Y12 receptor, inhibiting platelet aggregation and preventing amplification of platelet activation. Optimal dosing strategy as determined by ticagrelor's pharmacokinetic and pharmacodynamicprofileis a loadingdoseof 180 mg followedby90 mg bymouthtwicedaily. Atthesedoses, greater platelet inhibition is observed with ticagrelor as compared to clopidogrel 75 mg once daily in both clopidogrel-experienced and -naïve patients. Studies in patients experiencing ACS concluded that ticagrelor reduced the rate of cardiovascular death nonfatal myocardial infarction, stent thrombosis, and overall mortality compared to clopidogrel without increasing major bleeding when administered with standard therapy for ACS. There was no significant difference in the risk of stroke with ticagrelor compared to clopidogrel; however, intracranialbleedingwasmore commonwithticagrelor. Ticagreloris welltolerated; however, minor bleeding, dyspnea, hypotension, nausea, and ventricular pauses were reported more frequently than with clopidogrel. Reversible inhibition with ticagrelor may allow for more rapid surgical intervention after discontinuation, suggesting greater flexibility in treatment of ACS. Prehospitaladministration of ticagrelorin patients with acute STEMI appeared to be safe but did not improve pre-pci coronary reperfusion. (Funded by AstraZeneca; ATLANTIC Study(Montalescot et al. NEJM, 2014 )

19 Meta-analysis of direct and indirect comparison of ticagrelor and prasugrel effects on platelet reactivity The American Journal of Cardiology, 01/07/2015 Clinical Article Clinical Trial Below Lhermusier T, et al Methods The authorscomparedticagrelorwithprasugrelina networkmeta-analysis. PubMed, Cochrane, and EMBASE were searched for studies assessing platelet reactivity in coronary artery disease patients treated with ticagrelor or prasugrel. All studies using prasugrel and/or ticagrelor providing platelet function measurement data using VerifyNow P2Y12 Reaction Units(PRU), Platelet Reactivity Index vasodilator-stimulated phosphoprotein phosphorylation(pri-vasp), or maximal platelet aggregation(mpa) by light transmission aggregometry were considered eligible. Mixed treatment comparison models directly compared ticagrelor and prasugrel and indirectly compared them using clopidogrelasa comparatorwithdatapresentedasmeandifference[95% CI]. Data wereextractedfrom29 studies, including5395 patients. Results Compared with clopidogrel 75 mg, both prasugrel 10 mg and ticagrelor 90 mg bid were associated with lower PRU (meandifference-117 [-134.1, ] and [-182.6, ], respectively), a lowerpri (-24.2 [-28.2, -20.3] and [-39.9, -27.6], respectively), and lower MPA (-11.8 [-17, -6.3] and [-28.5, -12.8], respectively). Similar results were obtained with clopidogrel 150 mg. Ticagrelor 90 mg bid was associated with lower PRU (-42.5[-62.9, -21.9]), lower PRI (-9.3 [-15.6, -3.5]), and lower MPA (-8.9 [-16.4, -1.2]) compared with prasugrel 10 mg. Not a big trouvaille!

20 Elinogrel Originator: Portola Pharmaceuticals Inc. Licensee Novartis AG Status: Phase II Clinical Indication: Coronary artery disease ActionsCoagulationinhibitor, P2Y 12 purinoceptorantagonist, Plateletaggregationinhibitor Elinogrel is a novel, substituted-quinazolininedione phenyl thiophenyl-sulfonylurea P2Y12R antagonist that was discovered through high-throughput screening of an 180,000-compound library. T1/2 is hours. The preclinical data presented for elinogrel indicate that a direct-acting and reversible P2Y12R antagonist, such as elinogrel, may have a better therapeutic index (ie, less impact on hemostasis at equivalent levels of antithrombotic activity) than the thienopyridines. The potential clinical impact and success of elinogrelis currently difficult to predict because the drug is still undergoing phase II clinical development and no substantial results had been reported at the time of publication. However, elinogreldemonstrated valuable preliminary efficacy in early clinical trials and has been well tolerated. The fact that no additional bleeding was observed in patients

21 Newer antiplatelet compounds in clinical trials Trialsfor PCI, stroke, DM Agent Target Phase of development Indications SCH530348*: Thrombin receptor PAR-1 Phase III Acute coronary syndrome vorapaxar, atopaxar Cardiovascular disease E5555* : Thrombin receptor, PAR-1 Phase II Acute coronary syndrome Terutroban: Thromboxane receptor Phase III Stroke: secondary prevention Cilostazol: Phosphodiesterase inh. Phase III IV Approved for PVD Sarpogrelate: 5-HT2A serotonin inhibitor Phase IV Approved for PVD in Japan Trials for PCI, stroke vorapaxar: selektív orálisan aktív, hatékony, competitiv PAR-1 gátló. T1/2: óra Atopaxar T1/2: óra Klinikai vizsgálataik: FII FIII. : TRACER 2oP-TIMI50, LANCELOT-CAD

22 VORAPAXAR A thrombin receptor antagonist(par-1) In the study, researchers randomized 3,787 patients with PAD to receive standard care or standard care plus vorapaxar, the first in a new class of anti-platelet drugs called PAR-1 antagonists. Participants were part of the 26,449-patient TRA2P-TIMI 50 trialtesting 2.5 milligramsper day(mg/day) of vorapaxarinpeoplewitha historyof heartattack, stroke or PAD. The TRA2P-TIMI 50 trial main results presented earlier this year showed a statistically significant reductionincardiovasculareventsincludingheartattack, stroke, and cardiovasculardeathwithvorapaxar. In this substudy focused on participants with PAD, 11.3 percent of those taking vorapaxar experienced these major cardiovascular events compared with 11.9 percent of those taking a placebo a numeric reduction consistent with the overall trial findings that did not reach statistical significance on its own. However, they found benefits of vorapaxar on limb events. Compared to those not receiving the drug: Fewer vorapaxar patients were hospitalized for blood clots in the limbs(2.3 percent vs. 3.9 percent). Fewer vorapaxar patients required revascularization to restore full blood flow in narrowed or blocked vessels in the limbs (18.4 percent vs percent).

23 Antagonistagainstthecollagenreceptor, GPVI. PR-15 is a soluble variant of GPVI receptor. It is a monoclonal antibody to GPVIreceptor. It binds to exposed collagen and prevents GPVI mediated firm platelet adhesion and activation. Unlike other antiplatelet drugs, PR-15 targets receptors that are found on the activated platelets, which may potentially reduce the risk of bleeding associated with antiplatelet agents.

24 New antithrombotic strategies at molecular target level A protein disulfidisomerase(pdi) C terminalisactivcentrumának blokkolása 25 éves ismert, hogy a PDI felszabadul az aktíváltthrombocytákból, elhelyezkedik a thrombocyta felületen és részt vesz az aggregáció mediálásában. Kapcsolódik a αiibβ3 integrinhez(ami a fibrinogen receptor), hat a thrombocyta-függő thrombin generációra szabályozván az alvadási faktorok thrombocytához kötődését. A Quercetin-rutoside(növényekből, teákból, stb.) erősen gátolja a PDI-t. Fázis II/III vizsgálatok folynak isoquercetinnel a daganatos thrombotikus betegekben. JTH 2017 April A collagen-thrombocyta kölcsönhatás gátlói: kistomin, revacept a GP VI ellen, 6B4Fab maba GP I b ellen Serotonin receptor gátlók (l. ketanserin, de újabban APD791) Prostaglandin E receptor 3 antagonista: DG 041 NO donors: LA 846, LA 419 Phosphoinositol-3 kinase inhibitor /TGX-221)..és akkor még nem is beszéltünk régi kedvenceimről, a különböző kígyómérgek aggregációgátló hatóanyagairól!

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26 Antiplatelet substances: Cyclooxygenase inhibitors: Aspirin, Indobufen ADP receptor antagonists (Thienopyridines), Ticlopidine,Clopidogrel, Prasugrel, ADP receptor antagonists(nonthienopyridines): Cangrelor, Ticagrelor, Elinogrel Glycoprotein IIb/IIIa inhibitors: Abciximab, Tirofiban, Eptifibatide Defibrotide Phosphodiesterase inhibitors: Dipyridamole, Cilostazol, NT-702 (parogrelil hydrochloride), a selective phosphodiesterase (PDE)-3 inhibitor, rnm-702 Protease-activated receptor (PAR-1): inhibitors(thrombin receptor inhibitor), vorapaxar, E5555 Thromboxane A2 receptor inhibito:r Terutroban(S18886): Janus-faced: TXA2 inhibitor and PG-receptor antagonist Platelet adhesion antagonist: ARC1779 Serotonin 2A antagonists: sarpogrelate(in Japan, China, Korea only) C1qTNF-related protein-1 DZ-697b Nitric oxide releasing aspirin: NCX-4016 Collagen-platelet interaction inhibitor PR-15 Monoclonal antibodies Aptamers Small molecule peptide inhibitors

27 Klinikai döntéshozatal: A jövő viziója.. A rizikófelmérés a mindennapi gyakorlatnak a részévé kell válnia! A rizikó score-onak állandó finomítása, javítása elengedhetetlen. Legfontosabb követelmények: ágy mellett egyszerűen elvégezhetők legyenek! alkalmazkodjanak a beteg egyéni tulajdonságaihoz állapotához, comorbiditásaihoz! a guide-line-ok be-nem-tartását komolyan indokolni legyen szükséges!

28 Nagyon köszönöm a türelmüket és figyelmüket!

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31 VASP Assay PGE1 VASP = vasodilator-associated stimulated phosphoprotein + VASP > VASP-P VASP camp VASP-P VASP-P > VASP GP IIb/IIIa receptor activated - GP IIb/IIIa receptor inactivated Activated platelets Inhibited platelets Ticlopidine Clopidogrel ADP Schwarz UR et al. Thromb Haemost. 1999;82:1145. Geiger J et al. Arterioscler Thromb Vasc Biol. 1999;19:2007.

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41 Resistant Platelets: What Can Be Done? Uniformity of definition Improvement of laboratory assays (POC) Correlation of laboratory assays with clinical events Evaluation of new therapeutic strategies In the future customized patient therapy (pharmacogenomics)

42 Antithrombocyta szerek: Az adhaesio inhibitorai:von Willebrand faktor gátlók: A vwf kötődésének gátlás a GPIb-hez A GPIb kötőhelyek gátlása A vwf multimerizáció gátlása Pl. aurin tricarboxilsav, peptid fragmentek, amik a vwf-gpib-gpix kötő doménekből származnak,monoclonalis antitestek vwf ellen, stb. Az aggregáció gátlók ( GP IIb/IIIa gátlók) Monoclonalis antitestek: Szintetikus peptidek: iv adhatók: pl. Abciximab (ReoPro) tirofiban, Eptifibatide lamifiban I. generatios szerek: xemilofiban, Sibrafiban Orbofiban, Lotrafiban II. generatios oralis szerek: roxifiban, cromofiban (GR-83895, SHF , MK-852, DMP-728, BIBU-104, GR , L fejlesztés alatt) Kigyómérgek:barbourin, echistatin, kistrin, albolabrin,triflavin, applaggin, elegantin, eristicophin, decorsin, stb. A thrombocyta aktiváció gátlói: A cyclooxygenase út gátlói: Cyclooxygenase inhibitorok: aspirin, NSAIDok Indobufen, Triflusal Thromboxan synthetase gátlók: dazoxiben Thromboxan receptor antagonisták camp regulátorok Adenyl cyclase aktivátorok: prostacyclin, Beraprost, Cicaprost, Taprostene Phosphodiesterase gátlók: dipyridamole, Pentoxifyllin, Cilostazol, Trapidil A thrombin-mediált aktiváció gátlása: Thrombin inhiborok Thrombin receptor antagonisták Serotonin gátlók: ketanserin ADP-mediált aktiváció gátlása: P2Y12 blokkolók: ticlopidin, Clopidogrel Nem osztályozható hatású anyagok: Több hatásmechanizmussal gátlók: ditazole, Anagrelide Egyéb:buflomedil, lexipafant, nafazatrom, carbocromen, cloricromene, ronicol, vasopressin blokkolók, PAF-antag. Secunder thrombocyta gátlók: heparin, nitrátok, NO, fibrátok, Ca-csatorna blokkolók, ω-3-zsirsavak, stb.

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45 Inflammatory Balance Inflammation and Atherosclerosis TNFα IL-1 IL-8 IL-12 IL-15 IFNγ M-CSF MCP-1 IL-18 IL-6 IL-10 TGFβ IL-18BP

46 Chemical structures of ATP, cangrelor(ar-c69931mx), and ticagrelor(azd6140). Cattaneo M Circulation 2010;121: Copyright American Heart Association

47 Figure 2. Chemical structures of clopidogrel, prasugrel, and their active metabolites. Cattaneo M Circulation 2010;121: Copyright American Heart Association

48 TRICAGRELOR SOCRATES trial Acute stroke or transient ischemic attack treatet with Aspirin or Tricagrelol and patient outcome Summary: In cases of documentes atherosclerotic origin as the potential cause of TIA/stroke, tricagrelor is far better than aspirin inpreventingearlyrecurrence. (Pierre Amarenco NEJM 2017):, that ticagrelor has shown strong efficacy as an antiplatelet therapy in patients with coronary atherosclerotic disease and is therefore speculated to show greater benefit in patients with acute ischemia specifically of atherosclerotic origin. 13,199 pateints in 33 countries. That multicenter trial, conducted in 33 countries, showed that overall, ticagrelor was not superior to aspirin in the prevention of stroke recurrence, myocardial infarction, or death among patients with transient ischemic attack and minor stroke after 90 days of treatment Ticagrelor treatment consisted of a 180-mg loading dose on day 1 within 24 hours of symptom onset, followed by 90 mg twicedailyfordays2 to90, givenorally. Participantsintheaspiringroup(n = 6610) received300 mg onday1 within24 hoursof symptomonset, followedby100 mg dailyfordays2 to90, alsogivenorally. The results of the subanalysis showed a strong treatment by atherosclerotic stenosis interaction(p =.017). The rate of stroke, myocardial infarction, or death within 90 days was significantly lower in the group with ipsilateral stenosis treated with ticagrelor(6.7%; 103 patients) than in patients with ipsilateral stenosis in the aspirin group (9.6%; 147 patients; P =.003).