Interactions with Other Medications and Platelet Turnover Insights into Factors Affecting Responsiveness to Aspirin and Clopidogrel: Interactions with Other Medications and Platelet Turnover Paul A. Gurbel Sinai Center for Thrombosis Research Baltimore, Maryland, USA

Disclosures Honoraria/Consulting Research Grants/Support Pozen Pozen Astra Zeneca Nanosphere Accumetrics Helena Multiplate Portola Daiichi Honoraria/Consulting Pozen Novartis Bayer Astra Zeneca Eli Lilly Accumetrics Nanosphere Sanofi Aventis Boehringer Merck Medtronic 2

Drug-Drug Interactions: Oral Antiplatelet Therapy Aspirin NSAID’s Clopidogrel Proton Pump Inhibitors Smoking Calcium Channel Blockers Lipophilic Statins St. John’s Wort Rifampin Caffeine

Aspirin, NSAID’s and Platelet Function ASA acetylation site Converts AA to PGG2/PGH2 Ibuprofen reversibly blocks access of ASA to acetylation site Catella-Lawson et al. N Engl J Med 2001;345:1809-17

Aspirin, NSAID’s and Platelet Function - 400mg ibuprofen 2 h before 81mg ASA - same drugs in reverse order - 25mg rofecoxib 2h before 81mg ASA - same drugs in reverse order No effect of acetaminophen or diclofenac Catella-Lawson et al. N Engl J Med 2001;345:1809-17

Clopidogrel Response Variability: A PK Problem Intestinal Absorption Esterases 90% P-glycoprotein -PPI ? ? Limited absorption Two Step Conversion Hepatic P450 Cytochromes 10% 2C19, 1A2, 2B6 -PPI +Smoking Drug-Drug Interactions - Statin, -Ca+2 Antagonists + SJW, -PPI 2C19, 2C9, 3A4, 2B6 Variable Active Metabolite Generation + Caffeine via PDE inhibition Wide Pharmacodynamic Response, Nonresponsiveness Worse Clinical Outcome Adapted from Kauzi M et al. Drug Metab Dispos. 2009; Gurbel et al. J Inv Cardiol. 2009 6

CYP3A4: Clopidogrel - Atorvastatin/Rifampin Interaction CYP 3A4 Activity Directly Associated with Post-Clopidogrel Platelet Aggregation Before 300mg Clopidogrel Load After 300mg Clopidogrel Load Atorvastatin Dose Atorvastatin Increases Post-Clopidogrel Platelet Aggregation Baseline Clopidogrel Clopidogrel + Rifampin Rifampin Reduces Post-Clopidogrel Platelet Aggregation Lau W et al. Circulation 2003;107:32

CYP3A4: Clopidogrel - SJW Interaction 120 Clopidogrel 97 95 100 Clopidogrel + St. John's wort 300 mg TID 84 84 79 80 64 Platelet aggregation (%) 60 51 46 40 20 Baseline 2 hr 4 hr 6 hr Lau WC, Gurbel PA. Et al. J Cardiovasc Pharmacol. 2011;57:86-93 8

PDE Inhibition: Clopidogrel – Caffeine Interaction 20 Healthy Volunteers - 300mg CLP - 300mg caffeine 30 min after 300mg CLP 5 M ADP-Induced Aggregation p=0.02 Platelet Activation Markers Plasma cAMP Levels (fmol) Baseline 2.5 hrs post-caffeine 40 CAD Patients Post-PCI >1 wk 81-325mg ASA and 75mg CLP - 300mg caffeine p=0.01 p=0.02 Lev E et al. Am Heart J 2007:154;694.e1-694.e7

CYP2C19:Clopidogrel-PPI Interaction Gilard et al. J Am Coll Cardiol 2008;51:256-60 n=124 PCI patients Clopidogrel (300/600 mg LD and 75mg qd) +/- omeprazole for 7 d Omeprazole Control O’Donoghue ML et al. Lancet 2009;374:898-97 n=201 PCI patients 600mg Clopidogrel/ 60mg Prasugrel +/- PPI’s PRINCIPLE TIMI 44 Prasugrel 0.013 0.5 0.05 0.11 Clopidogrel 0.79 0.005 0.08 0.16 Adjusted p - value IN CLP and PRA Pts Treated with PPI at 15 d: LESS IPA (CLP + PPI, p =0.06; PRA + PPI, p=0.01) 10 10

CYP2C19: Clopidogrel–PPI Interaction PRI-VASP-P Prevalence of Non-Responders Cuisset T et al. J Am Coll Cardiol 2009;54:1149–53 Ho MP et al. JAMA 2009;30:1937-944 Clopidogrel Without PPI Clopidogrel With PPI Death or Rehosp. for ACS Rehosp. for ACS Revascl. for ACS All Cause Mortality OR=1.25 OR=1.86 OR=1.49 Patients (%) n = 8205 3-Year Clinical Outcome OR=0.91 11

ACS (STEMI or UA/NSTEMI) ACS (STEMI or UA/NSTEMI) Influence of PPI’s on Clinical Outcome in Patients Treated with Thienopyridine O’Donoghue ML et al. Lancet 2009;374:898-97 n=13,608 with ACS Clopidogrel/ Prasugrel +/-PPI Bhatt DL et al. N Engl J Med. 2010;363:1909-17 n= 3627 Clopidogrel + Omeprazole combo pill vs. Clopidogrel ACS (STEMI or UA/NSTEMI) ACS (STEMI or UA/NSTEMI) TRITON TIMI 38 COGENT Trial VERY IMPORTANT CAVEAT: NO SIGNIFICANT PLATELET FUNCTION MEASUREMENTS IN EITHER STUDY 12 12

THE SPACING STUDY P2Y12 antagonists Gurbel PA et al AHA 2010

Change in Platelet Reactivity by VerifyNow P2Y12 Assay PA32540 - Clopidogrel Interaction Change in Platelet Reactivity by VerifyNow P2Y12 Assay p<0.001 p<0.001 PRU 65 130 195 260 24 h Post-Load Day 7 p=0.048 p=0.003 * ECASA+C PA32540+C-S PA32540+C * p= 0.077 PA32540+C-S vs. PA32540+C Gurbel PA et al AHA 2010 14 14

5 uM ADP-Induced Aggregation (%) CYP3A4:Clopidogrel- Ca++ Channel Blockers Interaction Siller-Matula et al. J Am Coll Cardiol 2008;52:1557–63 LTA-ADP VASP-P P = 0.001 p=0.046 CYP1A2:Clopidogrel-Smoking Interaction 100 90 80 70 60 50 40 30 20 10 NS (< ½ pack) CS (> ½ pack) (n=72) (n=11) (n=37) p<0.05 5 uM ADP-Induced Aggregation (%) 20 uM ADP-Induced Aggregation (%) * (n=11) (n=37) Bliden KP et al. J Am Coll Cardiol 2008;52:531–3 15

CYP1A2: Smoking - Clopidogrel Interaction CHARISMA Trial: Berger J et al. Circulation 2009;120:2337-2344 All Cause and CV Death Bleeding CLARITY-TIMI 28 STUDY: Desai NR et al. J Am Coll Cardiol 2009;53:1273–8

Platelet Turnover and Antiplatelet Drug Response Variability: The 2 Platelet Pools Hypothesis Explanation for Differences In Antithrombotic Properties of Thienopyridines Versus Direct Acting P2Y12 Inhibitors ~ 10 % new platelets enter circulation each day Thienopyridine Metabolite Exposure (hours ) Exposure of circulating platelets to active thienopyridine metabolite is transient 2 24 As new platelets enter the circulation in the absence of circulating active thienopyridine metabolite they are not inhibited: young old blocked 2 platelet pools

Platelet Turnover and Antiplatelet Drug Response Variability: The 2 Platelet Pools Hypothesis Explanation for Differences In Antithrombotic Properties of Thienopyridines Versus Direct Acting P2Y12 Inhibitors Direct acting P2Y12 inhibitors provide uniform platelet inhibition dependent on drug plasma concentration: 1 Pool of Uniformly Inhibited Platelets blocked

Platelet Turnover and Antiplatelet Drug Response Variability: The 2 Platelet Pools Hypothesis Platelet turnover increased in ACS and Metabolic syndrome: Vadagunathan M et al. Am Heart J 2008;1546:1002.e1-1002.e7 Control UA NSTEMI STEMI Lakkis N et al. J Am Coll Cardiol 200444:2091-2093 % Reticulated Platelets Zimmerman N et al. Circulation. 2003;108:542-547 Young platelets have elevated COX-2: Aspirin insensitive TxA2 biosynthesis in CABG patients

Platelet Turnover and Aspirin Responsiveness in CABG 1mM AA-Induced Aggregation p<0.05 Days Post-CABG Days Post-CABG Platelet COX-1 and COX-2 Expression Zimmerman N et al. Circulation. 2003;108:542-547

Conclusions Ex vivo measurements of platelet function demonstrate important drug-drug interactions that affect response to clopidogrel. These interactions occur mainly at the hepatic CYP level, a pathway that metabolizes over half of the drugs prescribed. Ex vivo measurements of platelet function have been strongly linked to post-PCI ischemic risk. Physicians should be aware of these PD interactions particularly in patients with prior thrombotic events. We should not discount the importance of these interactions in the absence of results from adequately powered prospective clinical trials. Treatment with aspirin and thienopyridines during conditions associated with high platelet turnover are associated with: aspirin insensitive TxA2 generation blocked and unblocked pools of platelets 21 21 21

Influence of PON1 on Clopidogrel Response and Clinical Outcome PON1 genotype, paraoxonase plasma activity, plasma clopidogrel active metabolite concentration, and platelet inhibition in relation to nonfatal stent thrombosis No differences in CYP2C9, 2C19,3A4, 3A5, ABCB1 genotypes Bouman HJ, et al. Nat Med 2011;17:110-116

Influence of PON1 on Clopidogrel Response Variability 10% CYP3A4, CY3A5, CYP2B6, CYP1A2, CYP1A1, CYP2E1 and CYP2A6 Paraoxonase Drugs found to increase PON1 activity/expression Antioxidants found to increase PON1 activity/expression Costa LG et al. Biochem Pharmacol. 2011;81:337-44.