——Zontivity(vorapaxar)片-用于治疗高危患者中心脏发作和中风的新药
2014年5月8日美国食品药品监督管理局(FDA)批准Zontivity(vorapaxar)片减低心脏发作，中风，心血管死亡的风险，和在既往心脏发作为有既往心脏发作或至大腿动脉阻断患者中恢复至心脏血流需要程序。
Zontivity是一个心类别药物的第一个，被称为蛋白酶激活受体-1(PAR-1)拮抗剂。它是一种抗-血小板药物，设计成减低血小板聚集在一起形成血凝块的趋势。通过减低血凝块形成，Zontivity减低心脏发作和中风风险。.
像其他抑制血凝结药物一样，Zontivity增加出血风险，包括危及生命和致命性出血。服用Zontivity人们报道的最常见不良反应是出血。药物的处方资料包括一个黑框警告警戒卫生保健专业人员关于此风险。
在已经有中风，短暂性缺血发作(TIA)，或头内出血人们必须不用，因为头内出血风险太大。
FDA的药物评价和研究中心药物评价I室主任Ellis Unger医学博士说：“在有心脏发作或有外周动脉疾病患者，此药将减低心脏发作，中风，和心血管死亡的风险。在支持药物批准的研究中，Zontivity减低风险从9.5%至7.9%跨越3-年阶段–每年约0.5%”。
卫生保健专业人员应告知患者当他们服用Zontivity时他们可能更易出血和瘀伤。患者任何意外，延长或过量出血，或粪或尿血应报告他们的卫生保健专业人员。Zontivity将被与FDA-批准的患者用药指南一起分发为其使用和重要安全性信息提供指导。
在一项有超过25,000参加者临床试验中，Zontivity，添加至其他抗-血小板药物(一般是阿司匹林[aspirin]和氯吡格雷[clopidogrel])，当与无活性(安慰剂)药丸比较时减低心脏发作，中风，心血管死亡和禁忌程序的组合终点发生率，改善至心脏血流(冠状动脉血运重建)。
Zontivity是由新泽西州白宫默克公司子公司Merck Sharp & Dohme Corp.制造。
ZONTIVITY(vorapaxar)片为口服使用
*等同于2.5 mg硫酸vorapaxar
美国初次批准：2014
作用机制
Vorapaxar是一种表达在血小板上蛋白酶激活受体-1(PAR-1)的可逆性拮抗剂，但其长半衰期使它有效地不逆转。在体外研究中Vorapaxar抑制凝血酶-诱导和凝血酶受体激动剂肽(TRAP)-诱导的血小板聚集。Vorapaxar不抑制通过二磷酸腺苷(ADP)，胶原或一个血栓素模拟物诱导血小板聚集和在体外[ex vivo]不影响凝血参数。PAR-1受体也在广泛各种细胞类型上表达，包括内皮细胞，神经元，和平滑肌细胞，但未曾在这些类型细胞中评估药效动力学作用。
适应证和用途
ZONTIVITY是一种蛋白酶激活受体-1(PAR-1)拮抗剂适用为心肌梗死(MI)或有外周动脉疾病(PAD)史患者中血栓性心血管事件的减低。ZONTIVITY曾显示减低心血管死亡，MI，中风，和紧急冠状动脉血运重建的组合终点发生率。
剂量和给药方法
⑴ 口服一片ZONTIVITY每天1次。
⑵按其适应证或标准医护与阿司匹林[aspirin]和/或氯吡格雷[clopidogrel]使用。用其他抗血小板药物临床经验有限或用ZONTIVITY作为唯一的抗血小板药物。
剂型和规格
片：2.08mg vorapaxar。
禁忌证
⑴ 中风，TIA，或ICH史。
⑵ 活动性病理性出血。
警告或无注意事项
⑴ 像其他抗血小板药物，ZONTIVITY增加出血风险。
⑵ 避免使用强CYP3A抑制剂或诱导剂。
不良反应
出血，包括危及生命和致命性出血，是最常见报道的不良反应。

ZONTIVITY- vorapaxar sulfate tablet, film coated
Merck Sharp & Dohme Corp.

WARNING: BLEEDING RISK
•Do not use ZONTIVITY in patients with a history of stroke, transient ischemic attack (TIA), or intracranial hemorrhage (ICH); or active pathological bleeding [see CONTRAINDICATIONS (4.1, 4.2)].
•Antiplatelet agents, including ZONTIVITY, increase the risk of bleeding, including ICH and fatal bleeding [see Warnings and Precautions (5.1)].
1 INDICATIONS AND USAGE
1.1 Patients with History of Myocardial Infarction (MI) or with Peripheral Arterial Disease (PAD)
reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or with peripheral arterial disease (PAD). ZONTIVITY has been shown to reduce the rate of a combined endpoint of cardiovascular death, MI, stroke, and urgent coronary revascularization (UCR).
2 DOSAGE AND ADMINISTRATION
2.1 General Dosing Information
Take one tablet of ZONTIVITY 2.08 mg orally once daily, with or without food.
2.2 Coadministration with Other Antiplatelet Drugs
There is no experience with use of ZONTIVITY alone as the only administered antiplatelet agent. ZONTIVITY has been studied only as an addition to aspirin and/or clopidogrel. Use ZONTIVITY with aspirin and/or clopidogrel according to their indications or standard of care [see Clinical Studies (14)]. There is limited clinical experience with other antiplatelet drugs.
3 DOSAGE FORMS AND STRENGTHS
ZONTIVITY tablets, 2.08 mg vorapaxar, are yellow, oval-shaped, film-coated tablets with “351″ on one side and the Merck logo on the other side.
4 CONTRAINDICATIONS
4.1 History of Stroke, Transient Ischemic Attack (TIA), or Intracranial Hemorrhage (ICH)
ZONTIVITY is contraindicated in patients with a history of stroke, TIA, or ICH because of an increased risk of ICH in this population [see Adverse Reactions (6)].
5 WARNINGS AND PRECAUTIONS
5.1 General Risk of Bleeding
Antiplatelet agents, including ZONTIVITY, increase the risk of bleeding, including ICH and fatal bleeding [see Adverse Reactions (6.1)].
ZONTIVITY increases the risk of bleeding in proportion to the patient’s underlying bleeding risk. Consider the underlying risk of bleeding before initiating ZONTIVITY. General risk factors for bleeding include older age, low body weight, reduced renal or hepatic function, history of bleeding disorders, and use of certain concomitant medications (e.g., anticoagulants, fibrinolytic therapy, chronic nonsteroidal anti-inflammatory drugs [NSAIDS], selective serotonin reuptake inhibitors, serotonin norepinephrine reuptake inhibitors) increases the risk of bleeding [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3)]. Avoid concomitant use of warfarin or other anticoagulants.
Suspect bleeding in any patient who is hypotensive and has recently undergone coronary angiography, percutaneous coronary intervention (PCI), coronary artery bypass graft surgery (CABG), or other surgical procedures.
Withholding ZONTIVITY for a brief period will not be useful in managing an acute bleeding event because of its long half-life. There is no known treatment to reverse the antiplatelet effect of ZONTIVITY. Significant inhibition of platelet aggregation remains 4 weeks after discontinuation [see Overdosage (10) and Clinical Pharmacology (12.2, 12.3)].
5.2 Strong CYP3A Inhibitors or Inducers
Strong CYP3A inhibitors increase and inducers decrease ZONTIVITY exposure. Avoid concomitant use of ZONTIVITY with strong CYP3A inhibitors or inducers [see Drug Interactions (7.1) and Clinical Pharmacology (12.3)].
6 ADVERSE REACTIONS
The following serious adverse reaction is also discussed elsewhere in the labeling:
•Bleeding [see Boxed Warning and Warnings and Precautions (5.1)].
6.1 Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
ZONTIVITY was evaluated for safety in 13,186 patients, including 2,187 patients treated for more than 3 years, in the Phase 3 study TRA 2°P TIMI 50 (Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events). The overall study population, patients who had evidence or a history of atherosclerosis involving the coronary (post-MI), cerebral (ischemic stroke), or peripheral vascular (documented history of PAD) systems, was treated once a day with ZONTIVITY (n=13,186) or placebo (n=13,166). Patients randomized to ZONTIVITY received treatment for a median of 2.3 years.
The adverse events in the ZONTIVITY-treated (n=10,059) and placebo-treated (n=10,049) post-MI or PAD patients with no history of stroke or TIA are shown below [see Contraindications (4)].
Bleeding
GUSTO severe bleeding was defined as fatal, intracranial, or bleeding with hemodynamic compromise requiring intervention; GUSTO moderate bleeding was defined as bleeding requiring transfusion of whole blood or packed red blood cells without hemodynamic compromise. (GUSTO: Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries.)
The results for the bleeding endpoints in the post-MI or PAD patients without a history of stroke or TIA are shown in Table 1. ZONTIVITY increased GUSTO moderate or severe bleeding by 55%.
Table 1: Non-CABG-Related Bleeds in Post-MI or PAD Patients without a History of Stroke or TIA (First Dose to Last Dose + 30 Days) in the TRA 2°P Study
*Clinically significant bleeding includes any bleeding requiring medicalattention including ICH, or clinically significant overt signs of hemorrhage associated with a drop in hemoglobin (Hgb) of ≥3 g/dL (or, when Hgb is not available, an absolute drop in hematocrit (Hct) of ≥15% or a fall in Hct of 9 to <15%).
†Hazard ratio is ZONTIVITY group vs. placebo group.
‡K-M estimate at 1,080 days.
The effects of ZONTIVITY on bleeding were examined in a number of subsets based on demographic and other baseline characteristics. Many of these are shown in Figure 1. Such analyses must be interpreted cautiously, as differences can reflect the play of chance among a large number of analyses.
Figure 1: Subgroup Analyses (GUSTO Moderate or Severe Bleeding) in Post-MI or PAD Patients without a History of Stroke or TIA in the TRA 2°P Study (First Dose to Last Dose + 30 Days)
In TRA 2°P, 367 post-MI or PAD patients without a history of stroke or TIA underwent CABG surgery. Study investigators were encouraged not to discontinue treatment with study drug (i.e., ZONTIVITY or placebo) prior to surgery. Approximately 12.3% of patients discontinued ZONTIVITY more than 30 days prior to CABG. The relative risk for GUSTO moderate or severe bleeding was approximately 1.2 on ZONTIVITY vs. placebo.
Bleeding events that occurred on ZONTIVITY were treated in the same manner as for other antiplatelet agents.
Use in Patients with History of Stroke, TIA, or ICH
In the TRA 2°P study, patients with a history of ischemic stroke had a higher rate for ICH on ZONTIVITY than on placebo. ZONTIVITY is contraindicated in patients with a history of stroke, TIA, or ICH [see Contraindications (4)].
Other Adverse Reactions
Adverse reactions other than bleeding were evaluated in 19,632 patients treated with ZONTIVITY [13,186 patients in the TRA 2°P study and 6,446 patients in the TRA•CER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) study]. Adverse events other than bleeding that occurred at a rate that was at least 2% in the ZONTIVITY group and also 10% greater than the rate in the placebo group are shown in Table 2.
Table 2: TRA 2°P / TRA•CER — Percentage of Patients Reporting Non-hemorrhagic Adverse Reactions at a Rate at Least 2% in the ZONTIVITY Group and at Least 10% Greater than Placebo 
The following adverse reactions occurred at a rate less than 2% in the ZONTIVITY group but at least 40% greater than placebo. In descending order of rate in the ZONTIVITY group: iron deficiency, retinopathy or retinal disorder, and diplopia/oculomotor disturbances.
An increased rate of diplopia and related oculomotor disturbances was observed with ZONTIVITY treatment (30 subjects, 0.2%) vs. placebo (10 subjects, 0.06%). While some cases resolved during continued treatment, information on resolution of symptoms was not available for some cases.
7 DRUG INTERACTIONS
7.1 Effects of Other Drugs on ZONTIVITY
Vorapaxar is eliminated primarily by metabolism, with contributions from CYP3A4 and CYP2J2.
Strong CYP3A Inhibitors
Avoid concomitant use of ZONTIVITY with strong inhibitors of CYP3A (e.g., ketoconazole, itraconazole, posaconazole, clarithromycin, nefazodone, ritonavir, saquinavir, nelfinavir, indinavir, boceprevir, telaprevir, telithromycin and conivaptan) [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
with strong inducers of CYP3A (e.g., rifampin, carbamazepine, St. John’s Wort and phenytoin) [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Pregnancy Category B
There are no adequate and well-controlled studies of ZONTIVITY use in pregnant women.
Risk Summary
Based on data in rats and rabbits, ZONTIVITY is predicted to have a low probability of increasing the risk of adverse developmental outcomes above background. No embryo/fetal toxicities, malformations or maternal toxicities were observed in rats exposed during gestation to 56 times the human systemic exposure at the recommended human dose (RHD). No embryo/fetal toxicities, malformations or maternal toxicities were observed in rabbits exposed during gestation to 26 times the human systemic exposure at the RHD. The No Adverse Effect Level (NOAEL) for decreased perinatal survival and body weight in off-spring exposed in utero and during lactation was 31 times the human systemic exposure at the RHD. Both male and female pups displayed transient effects on sensory function and neurobehavioral development at weaning at 67 times the human exposure at the RHD, whereas female pups displayed decreased memory at 31 times the human exposure at the RHD. However, animal studies are not always predictive of a human response. ZONTIVITY should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus.
toxicity study, pregnant rats received daily oral doses of vorapaxar at 0, 5, 25, and 75 mg/kg from implantation to closure of the fetal hard palate (6th to 17th day of gestation). Maternal systemic exposures were approximately 0, 7, 56, and 285 times greater than exposures in women treated at the RHD based on AUC. No embryo/fetal toxicities, malformations, or maternal toxicities were observed in rats receiving exposures up to 56 times the human systemic exposure at the RHD.
In the rabbit embryo/fetal developmental toxicity study, pregnant rabbits received daily oral doses of vorapaxar at 0, 2, 10, or 20 mg/kg from implantation to closure of the fetal hard palate (7th to 19th day of gestation). The NOAEL for maternal and fetal toxicity was equal to or above the highest dose tested. However, an overall increase in the number of litters with any malformation was observed at the highest dose, where systemic exposures were 89-fold higher than the human exposure at RHD.
The effects of vorapaxar on prenatal and postnatal development were assessed in pregnant rats dosed at 0, 5, 25, or 50 mg/kg/day from implantation through the end of lactation. Rat pups had decreased survival and body weight gain from birth to postnatal day 4 and decreased body weight gain for the overall pre-weaning period at exposures 67 times the human exposure at the RHD. Both male and female pups displayed effects on sensory function (acoustic startle) and neurobehavioral (locomotor assay) development on post-natal day (PND) 20 and 21, but not later (PND 60, 61) in development, whereas decreased memory was observed in female pups on PND 27 at 31 times the human exposure at the RHD. In utero and lactational exposure did not affect fertility or reproductive behavior of offspring at exposures up to 67 times the RHD.
8.3 Nursing Mothers
It is unknown whether vorapaxar or its metabolites are excreted in human milk, but it is actively secreted in milk of rats. Because many drugs are excreted in human milk, and because of the potential for serious adverse reactions in nursing infants from ZONTIVITY, discontinue nursing or discontinue ZONTIVITY.
8.4 Pediatric Use
The safety and effectiveness of ZONTIVITY in pediatric patients have not been established.
8.5 Geriatric Use
In TRA 2°P, in post-MI or PAD patients without a history of stroke or TIA, 33% of patients were ≥65 years of age and 9% were ≥75 years of age. The relative risk of bleeding (ZONTIVITY compared with placebo) was similar across age groups. No overall differences in safety or effectiveness were observed between these patients and younger patients. ZONTIVITY increases the risk of bleeding in proportion to a patient’s underlying risk. Because older patients are generally at a higher risk of bleeding, consider patient age before initiating ZONTIVITY [see Adverse Reactions (6.1)].
8.6 Renal Impairment
No dose adjustment is required in patients with renal impairment [see Clinical Pharmacology (12.3)].
8.7 Hepatic Impairment
No dose adjustment is required in patients with mild and moderate hepatic impairment. Based on the increased inherent risk of bleeding in patients with severe hepatic impairment, ZONTIVITY is not recommended in such patients [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)].
10 OVERDOSAGE
There is no known treatment to reverse the antiplatelet effect of ZONTIVITY, and neither dialysis nor platelet transfusion can be expected to be beneficial if bleeding occurs after overdose. Inhibition of platelet aggregation can be expected for weeks after discontinuation of normal dosing [see Clinical Pharmacology (12.2)]. There is no standard test available to assess the risk of bleeding in an overdose situation.
11 DESCRIPTION
ZONTIVITY contains vorapaxar sulfate, a tricyclic himbacine-derived selective inhibitor of platelet aggregation mediated by PAR-1.
The chemical name of vorapaxar sulfate is ethyl [(1R,3aR,4aR,6R,8aR,9S,9aS)-9-{(1E)-2-[5-(3-fluorophenyl)pyridin-2-yl]ethen-1-yl}-1-methyl-3-oxododecahydronaphtho[2,3-c]furan-6-yl]carbamate sulfate. The empirical formula is C29 H33 FN2 O4 ∙H2 SO4 , and its molecular weight is 590.7. The structural formula is:
(click image for full-size original) Vorapaxar sulfate is a white to off-white solid. Vorapaxar sulfate is freely soluble in methanol and slightly soluble in ethanol, acetone, 2-propanol, and acetonitrile. In aqueous solution, it is slightly soluble in pH 1; its solubility decreases with increasing pH. ZONTIVITY tablets are formulated with vorapaxar sulfate, but during manufacture and storage, partial conversion from vorapaxar sulfate to vorapaxar free base may occur.
ZONTIVITY is available for oral use as tablets containing 2.08 mg of vorapaxar, which is equivalent to 2.5 mg of vorapaxar sulfate.
Each film-coated tablet of ZONTIVITY contains the following inactive ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, povidone, and magnesium stearate. In addition, the film coating contains the following inactive ingredients: lactose monohydrate, hypromellose, titanium dioxide, triacetin (glycerol triacetate), and iron oxide yellow.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
Vorapaxar is a reversible antagonist of the protease-activated receptor-1 (PAR-1) expressed on platelets, but its long half-life makes it effectively irreversible. Vorapaxar inhibits thrombin-induced and thrombin receptor agonist peptide (TRAP)-induced platelet aggregation in in vitro studies. Vorapaxar does not inhibit platelet aggregation induced by adenosine diphosphate (ADP), collagen or a thromboxane mimetic and does not affect coagulation parameters ex vivo. PAR-1 receptors are also expressed in a wide variety of cell types, including endothelial cells, neurons, and smooth muscle cells, but the pharmacodynamic effects of vorapaxar in these cell types have not been assessed.
12.2 Pharmacodynamics
At the recommended dose, ZONTIVITY achieves ≥80% inhibition of TRAP-induced platelet aggregation within one week of initiation of treatment. The duration of platelet inhibition is dose- and concentration-dependent. Inhibition of TRAP-induced platelet aggregation at a level of 50% can be expected at 4 weeks after discontinuation of daily doses of ZONTIVITY 2.08 mg, consistent with the terminal elimination half-life of vorapaxar [see Clinical Pharmacology (12.3)].
in platelet P-selectin and soluble CD40 ligand (sCD40L) expression or coagulation test parameters (TT, PT, aPTT, ACT, ECT) occurred after single- or multiple- dose (28 days) administration of vorapaxar. No meaningful changes in P-selectin, sCD40L, or hs-CRP concentrations were observed in patients treated with vorapaxar in the phase 2/3 clinical trials.
Evaluation of Vorapaxar on QTc Interval
The effect of vorapaxar on the QTc interval was evaluated in a thorough QT study and in other studies. Vorapaxar had no effect on the QTc interval at single doses up to 48 times the recommended dose.
12.3 Pharmacokinetics
Vorapaxar exposure increases in an approximately dose-proportional manner following single doses up to 16 times the recommended dose. Vorapaxar pharmacokinetics are similar in healthy subjects and patients.
Absorption
After oral administration of a single ZONTIVITY 2.08 mg dose under fasted conditions, peak concentrations (Cmax ) occur at 1 hour post-dose (range: 1 to 2 h). The mean absolute bioavailability as determined from a microdosing study is approximately 100%.
Ingestion of vorapaxar with a high-fat meal resulted in no meaningful change in AUC with a small (21%) decrease in Cmax and delayed time to peak concentration (45 minutes). ZONTIVITY may be taken with or without food.
Distribution
vorapaxar is approximately 424 liters (95% CI: 351-512). Vorapaxar and the major circulating active metabolite, M20, are extensively bound (≥99%) to human plasma proteins. Vorapaxar is highly bound to human serum albumin and does not preferentially distribute into red blood cells.
Metabolism
Vorapaxar is eliminated by metabolism via CYP3A4 and CYP2J2. The major active circulating metabolite is M20 (monohydroxy metabolite) and the predominant metabolite identified in excreta is M19 (amine metabolite). The systemic exposure of M20 is ~20% of the exposure to vorapaxar.
Excretion
The primary route of elimination is through the feces. In a 6-week study, 84% of the administered radiolabeled dose was recovered as total radioactivity with 58% collected in feces and 25% in urine. Vorapaxar is eliminated primarily in the form of metabolites, with no unchanged vorapaxar detected in urine.
Vorapaxar exhibits multi-exponential disposition with an effective half-life of 3-4 days and an apparent terminal elimination half-life of 8 days. Steady-state is achieved by 21 days following once-daily dosing with an accumulation of 5- to 6-fold. The apparent terminal elimination half-life for vorapaxar is approximately 8 days (range 5-13 days) and is similar for the active metabolite. The terminal elimination half-life is important to determine the time to offset the pharmacodynamic effect [see Clinical Pharmacology (12.2)].
Specific Populations
The effects of intrinsic factors on the pharmacokinetics of vorapaxar are presented in Figure 2 [see Use in Specific Populations (8.5, 8.6, 8.7)].
In general, effects on the exposure of vorapaxar based on age, race, gender, weight, and moderate renal insufficiency were modest (20-40%; see Figure 2). No dose adjustments are necessary based upon these factors. Because of the inherent bleeding risks in patients with severe hepatic impairment, ZONTIVITY is not recommended in such patients [see Warnings and Precautions (5.1) and Use in Specific Populations (8.7)].
Figure 2: Effect of Intrinsic Factors on the Pharmacokinetics of Vorapaxar
† See Warnings and Precautions. (5.1) and Use in Specific Populations. (8.7)
Drug Interactions [see also Drug Interactions (7)]
An interaction study with vorapaxar and warfarin in healthy subjects did not demonstrate a clinically significant pharmacokinetic or pharmacodynamic interaction [see Warnings and Precautions (5.1) and Figure 4].
Vorapaxar did not affect prasugrel pharmacokinetics and prasugrel did not affect vorapaxar pharmacokinetics following multiple-dose administration at steady-state [see Warnings and Precautions (5.1) and Figures 3 and 4]. The pharmacokinetic interaction between vorapaxar and clopidogrel has not been evaluated. However, the use of vorapaxar on a background of clopidogrel is supported by the clinical data from TRA 2°P and TRA•CER [see Adverse Reactions (6.1) and Clinical Studies (14)].
Effects of Other Drugs on Vorapaxar
The effects of other drugs on the pharmacokinetics of vorapaxar are presented in Figure 3 as change relative to vorapaxar administered alone (test/reference). Phase 3 data suggest that coadministration of a weak or moderate CYP3A inhibitor with vorapaxar does not increase bleeding risk or alter the efficacy of vorapaxar. No dose adjustment for ZONTIVITY is required in patients taking weak to moderate inhibitors of CYP3A.
Figure 3: Effects of Other Drugs on the Pharmacokinetics of Vorapaxar
ZONTIVITY (Page 3 of 5)
By Merck Sharp & Dohme Corp. | Last revised: 8 May 201412.2 PharmacodynamicsAt the recommended dose, ZONTIVITY achieves ≥80% inhibition of TRAP-induced platelet aggregation within one week of initiation of treatment. The duration of platelet inhibition is dose- and concentration-dependent. Inhibition of TRAP-induced platelet aggregation at a level of 50% can be expected at 4 weeks after discontinuation of daily doses of ZONTIVITY 2.08 mg, consistent with the terminal elimination half-life of vorapaxar [see Clinical Pharmacology (12.3)].
In healthy volunteer studies, no changes in platelet P-selectin and soluble CD40 ligand (sCD40L) expression or coagulation test parameters (TT, PT, aPTT, ACT, ECT) occurred after single- or multiple- dose (28 days) administration of vorapaxar. No meaningful changes in P-selectin, sCD40L, or hs-CRP concentrations were observed in patients treated with vorapaxar in the phase 2/3 clinical trials.
Evaluation of Vorapaxar on QTc Interval
The effect of vorapaxar on the QTc interval was evaluated in a thorough QT study and in other studies. Vorapaxar had no effect on the QTc interval at single doses up to 48 times the recommended dose.
12.3 PharmacokineticsVorapaxar exposure increases in an approximately dose-proportional manner following single doses up to 16 times the recommended dose. Vorapaxar pharmacokinetics are similar in healthy subjects and patients.
Absorption
After oral administration of a single ZONTIVITY 2.08 mg dose under fasted conditions, peak concentrations (Cmax ) occur at 1 hour post-dose (range: 1 to 2 h). The mean absolute bioavailability as determined from a microdosing study is approximately 100%.
Ingestion of vorapaxar with a high-fat meal resulted in no meaningful change in AUC with a small (21%) decrease in Cmax and delayed time to peak concentration (45 minutes). ZONTIVITY may be taken with or without food.
Distribution
The mean volume of distribution of vorapaxar is approximately 424 liters (95% CI: 351-512). Vorapaxar and the major circulating active metabolite, M20, are extensively bound (≥99%) to human plasma proteins. Vorapaxar is highly bound to human serum albumin and does not preferentially distribute into red blood cells.
Metabolism
Vorapaxar is eliminated by metabolism via CYP3A4 and CYP2J2. The major active circulating metabolite is M20 (monohydroxy metabolite) and the predominant metabolite identified in excreta is M19 (amine metabolite). The systemic exposure of M20 is ~20% of the exposure to vorapaxar.
Excretion
The primary route of elimination is through the feces. In a 6-week study, 84% of the administered radiolabeled dose was recovered as total radioactivity with 58% collected in feces and 25% in urine. Vorapaxar is eliminated primarily in the form of metabolites, with no unchanged vorapaxar detected in urine.
Vorapaxar exhibits multi-exponential disposition with an effective half-life of 3-4 days and an apparent terminal elimination half-life of 8 days. Steady-state is achieved by 21 days following once-daily dosing with an accumulation of 5- to 6-fold. The apparent terminal elimination half-life for vorapaxar is approximately 8 days (range 5-13 days) and is similar for the active metabolite. The terminal elimination half-life is important to determine the time to offset the pharmacodynamic effect [see Clinical Pharmacology (12.2)].
Specific Populations
The effects of intrinsic factors on the pharmacokinetics of vorapaxar are presented in Figure 2 [see Use in Specific Populations (8.5, 8.6, 8.7)].
In general, effects on the exposure of vorapaxar based on age, race, gender, weight, and moderate renal insufficiency were modest (20-40%; see Figure 2). No dose adjustments are necessary based upon these factors. Because of the inherent bleeding risks in patients with severe hepatic impairment, ZONTIVITY is not recommended in such patients [see Warnings and Precautions (5.1) and Use in Specific Populations (8.7)].
Figure 2: Effect of Intrinsic Factors on the Pharmacokinetics of Vorapaxar
See Warnings and Precautions. (5.1) and Use in Specific Populations. (8.7)
(click image for full-size original)
Drug Interactions [see also Drug Interactions (7)]
Anticoagulants and Antiplatelet Agents
An interaction study with vorapaxar and warfarin in healthy subjects did not demonstrate a clinically significant pharmacokinetic or pharmacodynamic interaction [see Warnings and Precautions (5.1) and Figure 4].
Vorapaxar did not affect prasugrel pharmacokinetics and prasugrel did not affect vorapaxar pharmacokinetics following multiple-dose administration at steady-state [see Warnings and Precautions (5.1) and Figures 3 and 4]. The pharmacokinetic interaction between vorapaxar and clopidogrel has not been evaluated. However, the use of vorapaxar on a background of clopidogrel is supported by the clinical data from TRA 2°P and TRA•CER [see Adverse Reactions (6.1) and Clinical Studies (14)].
Effects of Other Drugs on Vorapaxar
The effects of other drugs on the pharmacokinetics of vorapaxar are presented in Figure 3 as change relative to vorapaxar administered alone (test/reference). Phase 3 data suggest that coadministration of a weak or moderate CYP3A inhibitor with vorapaxar does not increase bleeding risk or alter the efficacy of vorapaxar. No dose adjustment for ZONTIVITY is required in patients taking weak to moderate inhibitors of CYP3A.
Figure 3: Effects of Other Drugs on the Pharmacokinetics of Vorapaxar
See Warnings and Precautions. (5.2) and Drug Interactions. (7.1)
See Dosage and Administration. (2.2)
Effects of Vorapaxar on Other Drugs
In vitro metabolism studies demonstrate that vorapaxar or M20 is unlikely to cause clinically significant inhibition or induction of major CYP isoforms or inhibition of OATP1B1, OATP1B3, BCRP, OAT1, OAT3, and OCT2 transporters.
Specific in vivo effects on the pharmacokinetics of digoxin, warfarin, rosiglitazone and prasugrel are presented in Figure 4 as a change relative to the interacting drug administered alone (test/reference). Vorapaxar is a weak inhibitor of the intestinal P-glycoprotein (P-gp) transporter. No dosage adjustment of digoxin or ZONTIVITY is required.
Figure 4: Effects of Vorapaxar on the Pharmacokinetics of Other Drugs
See Warnings and Precautions. (5.1)
See Dosage and Administration. (2.2)
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
Carcinogenicity studies were conducted in rats and mice dosed orally with vorapaxar for two years. Male and female rats dosed at 0, 3, 10 or 30 mg/kg/day showed no carcinogenic potential at systemic exposures (AUC) in males and females that were 9- and 29-fold, respectively, the human systemic exposure at the RHD. In male and female mice dosed at 0, 1, 5, and 15 mg/kg/day, vorapaxar showed no carcinogenic potential at systemic exposures (AUC) that were up to 30-fold the human systemic exposure.
Ames bacterial reverse mutation assay and not clastogenic in an in vitro human peripheral blood lymphocyte assay or an in vivo mouse micronucleus assay after intraperitoneal administration.
Impairment of Fertility
Fertility studies in rats showed that vorapaxar had no effect on either male or female fertility at doses up to 50 mg/kg/day, a dose resulting in systemic exposures (AUC) in male and female rats that are 40 and 67 times, respectively, the human systemic exposure at the RHD.
13.2 Animal Pharmacology
Vorapaxar did not increase bleeding time in non-human primates when administered alone. Bleeding time was prolonged slightly with administration of aspirin or aspirin plus vorapaxar. The combination of aspirin, vorapaxar, and clopidogrel produced significant prolongation of bleeding time. Transfusion of human platelet rich plasma normalized bleeding times with partial recovery of ex vivo platelet aggregation induced with arachidonic acid, but not induced with ADP or TRAP. Platelet poor plasma had no effect on bleeding times or platelet aggregation [see Warnings and Precautions (5.1)].
14 CLINICAL STUDIES
The clinical evidence for the effectiveness of ZONTIVITY is supported by TRA 2°P — TIMI 50. TRA 2°P was a multicenter, randomized, double-blind, placebo-controlled study conducted in patients who had evidence or a history of atherosclerosis involving the coronary (spontaneous MI ≥2 weeks but ≤12 months prior), cerebral (ischemic stroke), or peripheral vascular (documented peripheral arterial disease [PAD]) systems. Patients were randomized to receive daily treatment with ZONTIVITY (n=13,225) or placebo (n=13,224) in addition to standard of care. The study’s primary endpoint was the composite of cardiovascular death, MI, stroke, and urgent coronary revascularization (UCR). The composite of cardiovascular death, MI, and stroke was assessed as key secondary endpoint. The median follow-up was 2.5 years (up to 4 years).
for the primary efficacy composite endpoint show a 3-year K-M event rate of 11.2% in the ZONTIVITY group compared to 12.4% in the placebo group (hazard ratio [HR]: 0.88; 95% confidence interval [CI], 0.82 to 0.95; p=0.001).
The findings for the key secondary efficacy endpoint show a 3-year Kaplan-Meier (K-M) event rate of 9.3% in the ZONTIVITY group compared to 10.5% in placebo group (HR 0.87; 95% CI, 0.80 to 0.94; p<0.001).
Although TRA 2°P was not designed to evaluate the relative benefits and risks of ZONTIVITY in individual patient subgroups, patients with a history of stroke or TIA showed an increased risk of ICH. Of the patients who comprised the post-MI and PAD strata and had no baseline history of stroke or TIA,10,080 were randomized to treatment with ZONTIVITY and 10,090 to placebo. These patients were 89% Caucasian, 22% female, and 33% ≥65 years of age, with a median age of 60 years. The population included patients with diabetes (24%) and patients with hypertension (65%). Of the patients who qualified for the trial with MI without a history of stroke or TIA, 98% were receiving aspirin, 78% were receiving a thienopyridine, and 77% were receiving both aspirin and a thienopyridine when they enrolled in the trial. Of the patients who qualified for the trial with PAD without a history of stroke or TIA, 88% were receiving aspirin, 35% were receiving a thienopyridine, and 27% were receiving both aspirin and a thienopyridine when they enrolled.
In post-MI or PAD patients without a history of stroke or TIA the 3-year K-M event rate for the primary efficacy endpoint (composite of time to first CV death, MI, stroke, or UCR) was of 10.1% in the ZONTIVITY group compared to 11.8% in the placebo group (HR 0.83; 95% CI, 0.76 to 0.90; p<0.001) (see Figure 5 and Table 3).
The results for the key secondary efficacy endpoint (composite of time to first CV death, MI, or stroke) show a 3-year K-M event rate of 7.9% in the ZONTIVITY group compared to 9.5% in the placebo group (HR 0.80; 95% CI, 0.73 to 0.89; p<0.001) (see Table 3).
The effect of chronic dosing with ZONTIVITY on the primary and key secondary endpoints was maintained for the duration of the trial (median follow up 2.5 years, up to 4 years).
Figure 5: Time to First Occurrence of the Composite Endpoint of CV Death, MI, Stroke or UCR in Post-MI or PAD Patients without a History of Stroke or TIA in TRA 2°P
Table 3: TRA 2°P: Time to First Event in Post-MI or PAD Patients without a History of Stroke or TIA
ZONTIVITY (Page 4 of 5)
By Merck Sharp & Dohme Corp. | Last revised: 8 May 201413 NONCLINICAL TOXICOLOGY13.1 Carcinogenesis, Mutagenesis, Impairment of FertilityCarcinogenesis
Carcinogenicity studies were conducted in rats and mice dosed orally with vorapaxar for two years. Male and female rats dosed at 0, 3, 10 or 30 mg/kg/day showed no carcinogenic potential at systemic exposures (AUC) in males and females that were 9- and 29-fold, respectively, the human systemic exposure at the RHD. In male and female mice dosed at 0, 1, 5, and 15 mg/kg/day, vorapaxar showed no carcinogenic potential at systemic exposures (AUC) that were up to 30-fold the human systemic exposure.
Mutagenesis
Vorapaxar was not mutagenic in the Ames bacterial reverse mutation assay and not clastogenic in an in vitro human peripheral blood lymphocyte assay or an in vivo mouse micronucleus assay after intraperitoneal administration.
Impairment of Fertility
Fertility studies in rats showed that vorapaxar had no effect on either male or female fertility at doses up to 50 mg/kg/day, a dose resulting in systemic exposures (AUC) in male and female rats that are 40 and 67 times, respectively, the human systemic exposure at the RHD.
13.2 Animal PharmacologyVorapaxar did not increase bleeding time in non-human primates when administered alone. Bleeding time was prolonged slightly with administration of aspirin or aspirin plus vorapaxar. The combination of aspirin, vorapaxar, and clopidogrel produced significant prolongation of bleeding time. Transfusion of human platelet rich plasma normalized bleeding times with partial recovery of ex vivo platelet aggregation induced with arachidonic acid, but not induced with ADP or TRAP. Platelet poor plasma had no effect on bleeding times or platelet aggregation [see Warnings and Precautions (5.1)].
14 CLINICAL STUDIESThe
clinical evidence for the effectiveness of ZONTIVITY is supported by TRA 2°P — TIMI 50. TRA 2°P was a multicenter, randomized, double-blind, placebo-controlled study conducted in patients who had evidence or a history of atherosclerosis involving the coronary (spontaneous MI ≥2 weeks but ≤12 months prior), cerebral (ischemic stroke), or peripheral vascular (documented peripheral arterial disease [PAD]) systems. Patients were randomized to receive daily treatment with ZONTIVITY (n=13,225) or placebo (n=13,224) in addition to standard of care. The study’s primary endpoint was the composite of cardiovascular death, MI, stroke, and urgent coronary revascularization (UCR). The composite of cardiovascular death, MI, and stroke was assessed as key secondary endpoint. The median follow-up was 2.5 years (up to 4 years).
The findings in all randomized patients for the primary efficacy composite endpoint show a 3-year K-M event rate of 11.2% in the ZONTIVITY group compared to 12.4% in the placebo group (hazard ratio [HR]: 0.88; 95% confidence interval [CI], 0.82 to 0.95; p=0.001).
The findings for the key secondary efficacy endpoint show a 3-year Kaplan-Meier (K-M) event rate of 9.3% in the ZONTIVITY group compared to 10.5% in placebo group (HR 0.87; 95% CI, 0.80 to 0.94; p<0.001).
Although TRA 2°P was not designed to evaluate the relative benefits and risks of ZONTIVITY in individual patient subgroups, patients with a history of stroke or TIA showed an increased risk of ICH. Of the patients who comprised the post-MI and PAD strata and had no baseline history of stroke or TIA,10,080 were randomized to treatment with ZONTIVITY and 10,090 to placebo. These patients were 89% Caucasian, 22% female, and 33% ≥65 years of age, with a median age of 60 years. The population included patients with diabetes (24%) and patients with hypertension (65%). Of the patients who qualified for the trial with MI without a history of stroke or TIA, 98% were receiving aspirin, 78% were receiving a thienopyridine, and 77% were receiving both aspirin and a thienopyridine when they enrolled in the trial. Of the patients who qualified for the trial with PAD without a history of stroke or TIA, 88% were receiving aspirin, 35% were receiving a thienopyridine, and 27% were receiving both aspirin and a thienopyridine when they enrolled.
In post-MI or PAD patients without a history of stroke or TIA the 3-year K-M event rate for the primary efficacy endpoint (composite of time to first CV death, MI, stroke, or UCR) was of 10.1% in the ZONTIVITY group compared to 11.8% in the placebo group (HR 0.83; 95% CI, 0.76 to 0.90; p<0.001) (see Figure 5 and Table 3).
The results for the key secondary efficacy endpoint (composite of time to first CV death, MI, or stroke) show a 3-year K-M event rate of 7.9% in the ZONTIVITY group compared to 9.5% in the placebo group (HR 0.80; 95% CI, 0.73 to 0.89; p<0.001) (see Table 3).
The effect of chronic dosing with ZONTIVITY on the primary and key secondary endpoints was maintained for the duration of the trial (median follow up 2.5 years, up to 4 years).
Figure 5: Time to First Occurrence of the Composite Endpoint of CV Death, MI, Stroke or UCR in Post-MI or PAD Patients without a History of Stroke or TIA in TRA 2°P (click image for full-size original)
Table 3: TRA 2°P: Time to First Event in Post-MI or PAD Patients without a History of Stroke or TIA  Placebo(n=10,090) ZONTIVITY(n=10,080)  
Endpoints Patients with events *(%) K-M % Patients with events *(%) K-M %† Hazard Ratio , (95% CI) p-value
*Each patient was counted only once (first component event) in the component summary that contributed to the primary efficacy endpoint.
K-M estimate at 1,080 days.
Hazard ratio is ZONTIVITY group versus placebo group.
Cox proportional hazard model with covariates treatment and stratification factors (qualifying atherosclerotic disease and planned thienopyridine use).
Including patients who could have had other non-fatal events or subsequently died.
In post-MI or PAD patients who survived an on-study efficacy event, the incidence of subsequent events was lower with ZONTIVITY.
The time from the prior MI to randomization had no relationship to the treatment benefit for the primary study outcome.
A range of demographic, concurrent baseline medications, and other treatment differences were examined for their influence on outcomes as shown in Figure 6. Such analyses must be interpreted cautiously, as differences can reflect the play of chance among a large number of analyses.
Figure 6: Subgroup Analyses (Primary Endpoints) of the TRA 2°P Post-MI or PAD Patients without a History of Stroke or TIA
16 HOW SUPPLIED/STORAGE AND HANDLING
ZONTIVITY tablets, 2.08 mg vorapaxar, are yellow, oval-shaped, film-coated tablets with “351″ on one side and the Merck logo on the other side.
They are supplied as follows:
•NDC 0006-0351-31 bottles of 30 tablets
•NDC 0006-0351-54 bottles of 90 tablets
•NDC 0006-0351-48 unit dose packages of 100 tablets (one carton containing 10 10-count blister cards)
permitted between 15-30°C (between 59-86°F). [See USP Controlled Room Temperature.] Store tablets in the original package with the bottle tightly closed. Keep the desiccant in the bottle to protect from moisture.
Storage of blisters
Store at 20-25°C (68-77°F), excursions permitted between 15-30°C (between 59-86°F). [See USP Controlled Room Temperature.] Store in the original package until use.