Intravenous Clopidogrel (MDCO-157) Compared with Oral Clopidogrel: The Randomized Cross-Over AMPHORE Study

In Vitro-In Silico Approach in the Development of Clopidogrel Solid Dispersion Formulations

The aim of this study was to investigate the influence of solid dispersion (SD) formulation factors on improvement of the bioavailability and pharmacokinetic profile of clopidogrel after peroral administration using an in vitro-in silico approach. A clopidogrel-specific, physiologically based biopharmaceutical model (PBBM) was developed and validated to predict absorption and distribution of clopidogrel after peroral administration of the tested formulations. Clopidogrel solid dispersions were prepared using two polymers (poloxamer 407 and copovidone) and a drug-to-polymer ratio of 1:5 and 1:9. The results of the in vitro dissolution test under pH-media change conditions showed that the type and ratio of polymers notably influenced the release of clopidogrel from the SDs. It can be observed that an increase in the polymer content in the SDs leads to a decrease in the release of clopidogrel from the SDs. The predictive power of the constructed clopidogrel-specific PBBM was demonstrated by comparing the simulation results with pharmacokinetic data from the literature. The in vitro dissolution data were used as inputs for the PBBM to predict the pharmacokinetic profiles of clopidogrel after the peroral administration of SDs. SDs with copovidone (1:5) and poloxamer (1:9) showed the potential to achieve the highest drug absorption and bioavailability, with an improvement of over 100% compared to an immediate-release (IR) tablet. The sample with poloxamer (1:9) may have the potential to reduce inter-individual variability in clopidogrel pharmacokinetics due to absorption in the cecum and colon and associated lower first-pass metabolism in the liver. This suggests that distal intestine may be the targeted delivery site for clopidogrel, leading to improved absorption and bioavailability of the drug. This study has shown that an in vitro-in silico approach could be a useful tool for the development and optimization of clopidogrel formulations, helping in decision making regarding the composition of the formulation to achieve the desired pharmacokinetic profile.

P2Y12 Inhibitor Loading Time Before Elective PCI and the Prevention of Myocardial Necrosis

BACKGROUND

There are dated and conflicting data about the optimal timing of initiation of P2Y12 inhibitors in elective percutaneous coronary intervention (PCI). Peri-PCI myocardial necrosis is associated with poor outcomes. We aimed to assess the impact of the P2Y12 inhibitor loading time on periprocedural myocardial necrosis in the population of the randomized Assessment of Loading With the P2Y12 Inhibitor Ticagrelor or Clopidogrel to Halt Ischemic Events in Patients Undergoing Elective Coronary Stenting (ALPHEUS) trial, which compared ticagrelor with clopidogrel in high-risk patients who received elective PCI.

METHODS

The ALPHEUS trial divided 1809 patients into quartiles of loading time. The ALPHEUS primary outcome was used (type 4 [a or b] myocardial infarction or major myocardial injury) as well as the main secondary outcome (type 4 [a or b] myocardial infarction or any type of myocardial injury).

RESULTS

Patients in the first quartile group (Q1) presented higher rates of the primary outcome (P = 0.01). When compared with Q1, incidences of the primary outcome decreased in patients with longer loading times (adjusted odds ratio [adjOR], 0.70 [0.52.-0.95]; P = 0.02 for Q2; adjOR 0.65 [0.48-0.88]; P < 0.01 for Q3; adjOR 0.66 [0.49-0.89]; P < 0.01 for Q4). Concordant results were found for the main secondary outcome. There was no interaction with the study drug allocated by randomization (clopidogrel or ticagrelor). Bleeding complications (any bleeding ranging between 4.9% and 7.3% and only 1 major bleeding at 48 hours) and clinical ischemic events were rare and did not differ among groups.

CONCLUSIONS

In elective PCI, administration of the oral P2Y12 inhibitor at the time of PCI could be associated with more frequent periprocedural myocardial necrosis than an earlier administration. The long-term clinical consequences remain unknown.

Physiologically Based Pharmacokinetic (PBPK) Modeling of Clopidogrel and Its Four Relevant Metabolites for CYP2B6, CYP2C8, CYP2C19, and CYP3A4 Drug–Drug–Gene Interaction Predictions

The antiplatelet agent clopidogrel is listed by the FDA as a strong clinical index inhibitor of cytochrome P450 (CYP) 2C8 and weak clinical inhibitor of CYP2B6. Moreover, clopidogrel is a substrate of—among others—CYP2C19 and CYP3A4. This work presents the development of a whole-body physiologically based pharmacokinetic (PBPK) model of clopidogrel including the relevant metabolites, clopidogrel carboxylic acid, clopidogrel acyl glucuronide, 2-oxo-clopidogrel, and the active thiol metabolite, with subsequent application for drug–gene interaction (DGI) and drug–drug interaction (DDI) predictions. Model building was performed in PK-Sim^® using 66 plasma concentration-time profiles of clopidogrel and its metabolites. The comprehensive parent-metabolite model covers biotransformation via carboxylesterase (CES) 1, CES2, CYP2C19, CYP3A4, and uridine 5′-diphospho-glucuronosyltransferase 2B7. Moreover, CYP2C19 was incorporated for normal, intermediate, and poor metabolizer phenotypes. Good predictive performance of the model was demonstrated for the DGI involving CYP2C19, with 17/19 predicted DGI AUC_last and 19/19 predicted DGI C_max ratios within 2-fold of their observed values. Furthermore, DDIs involving bupropion, omeprazole, montelukast, pioglitazone, repaglinide, and rifampicin showed 13/13 predicted DDI AUC_last and 13/13 predicted DDI C_max ratios within 2-fold of their observed ratios. After publication, the model will be made publicly accessible in the Open Systems Pharmacology repository.

Do we need a new P2Y12 receptor antagonist?

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A Safety Evaluation of Cangrelor in Patients Undergoing PCI

INTRODUCTION

Dual antiplatelet therapy with aspirin and an oral ADP P2Y12 receptor antagonist is the standard-of-care for treatment of patients undergoing percutaneous coronary intervention (PCI). However, oral P2Y12 receptor antagonists have several limitations, including inter- and intra-individual response variability, drug-drug interactions, slow onset and offset of action and delayed platelet inhibition in high-risk clinical settings, such as patients with ST-segment elevation myocardial infarction.

AREAS COVERED

Cangrelor is an intravenous, direct-acting, reversible, potent P2Y12 receptor antagonist. It rapidly achieves near complete platelet inhibition and has a very short half-life and a fast offset of action. We conducted a systematic review searching PubMed/MEDLINE for pharmacodynamic/pharmacokinetic studies and clinical trials in which cangrelor was investigated, published from any time up to November 1(st) 2015. For clinical trials, those investigating cangrelor in the setting of PCI were considered for discussion.

EXPERT OPINION

Cangrelor is approved by drug regulating authorities worldwide as adjunctive antithrombotic therapy for the full spectrum of patients undergoing PCI, not pre-treated with a P2Y12 receptor inhibitor and not with intent to receive a glycoprotein IIb/IIIa inhibitor. Its unique pharmacological properties and its favorable safety and efficacy profile make it an attractive treatment strategy, especially in clinical settings where immediate platelet inhibition is required.