Wei Li

Daiichi Sankyo, Parsippany, New Jersey, United States

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Publications (4)34.25 Total impact

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    ABSTRACT: On-treatment platelet reactivity (OTR) is a predictor of clinical outcomes in patients receiving thienopyridine therapy. To assess whether point-of-care platelet reactivity testing can discriminate between patients who have and have not been administered a thienopyridine. This was an analysis of a randomized, multicenter, pharmacodynamic trial. Subjects with coronary artery disease treated with aspirin were randomly assigned to clopidogrel 75mg daily or prasugrel 10mg daily for 7 days. Platelet reactivity assessment with the VerifyNow P2Y12 test was performed before study drug and 24 hours after the final dose. Optimal cut-offs for a detectable drug effect were identified using receiver-operator characteristic curve analysis. A total of 54 subjects were enrolled and completed the study. The c-statistic for the identification of a thienopyridine effect was highly significant (0.93, p<0.001), including for the clopidogrel and prasugrel groups considered separately p<0.001 for both). The optimal cut-off was <213 PRU, which provided a sensitivity of 80% and a specificity of 98%. This cutoff provided a sensitivity of 58% and a specificity of 100% for clopidogrel effect, and a sensitivity of 100% and specificity of 96% for prasugrel effect. OTR <213 PRU is highly specific for exposure to either clopidogrel or prasugrel. This may be useful in the management of thienoypridine-treated patients who require surgery. Furthermore, this diagnostic cut-off is similar to levels of OTR that have been associated with ischemic events in thienopyridine-treated patients, supporting the contention that a lack of drug effect is the mechanistic basis for the prognostic relationship between OTR and clinical outcomes. This article is protected by copyright. All rights reserved.
    Journal of Thrombosis and Haemostasis 01/2014; · 6.08 Impact Factor
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    ABSTRACT: To evaluate the pharmacodynamic effects of switching from ticagrelor to prasugrel. Clinicians may need to switch between more potent P2Y12 inhibitors because of side effects or use of a once-daily dosing regimen due to compliance issues. After a 3-5 day run-in phase with ticagrelor 180-mg loading dose (LD) followed by ticagrelor 90-mg twice-daily maintenance dose (MD), aspirin-treated subjects (n=110) with stable coronary artery disease were randomized to continue ticagrelor or switch to prasugrel 10 mg once-daily MD, with or without a 60-mg LD. Pharmacodynamic assessments were defined by P2Y12 reaction unit (PRU, VerifyNow(®) P2Y12 assay) and platelet reactivity index (PRI, vasodilator-stimulated phosphoprotein phosphorylation assay) at baseline (before and after the run-in phase) and 2, 4, 24, and 48 hours and 7 days after randomization. Platelet reactivity was significantly greater at 24 and 48 hours after switching to prasugrel versus continued therapy with ticagrelor, although to a lesser extent in those receiving an LD. Mean PRU remained significantly higher in the combined prasugrel group versus ticagrelor (least-squares mean difference: 46; 95% confidence interval [CI]: 25-67) and did not meet the primary non-inferiority endpoint (upper limit of the CI ≤45), although PRU in the prasugrel cohort was lower at 7 days than at 24 or 48 hours. Accordingly, rates of high on-treatment platelet reactivity (HPR) were higher at 24 and 48 hours in both prasugrel groups; at 7 days there was no difference in HPR frequency between the combined prasugrel and ticagrelor groups. As compared to continued ticagrelor therapy, switching from ticagrelor to prasugrel therapy is associated with an increase in platelet reactivity that is partially mitigated by the administration of an LD.
    Journal of the American College of Cardiology 12/2013; · 14.09 Impact Factor
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    ABSTRACT: The goal of this study was to assess the offset of the antiplatelet effects of prasugrel and clopidogrel. Guidelines recommend discontinuing clopidogrel at least 5 days and prasugrel at least 7 days before surgery. The pharmacodynamic basis for these recommendations is limited. Aspirin-treated patients with coronary artery disease were randomly assigned to either prasugrel 10 mg or clopidogrel 75 mg daily for 7 days. Platelet reactivity was measured before study drug administration and for up to 12 days during washout. The primary endpoint was the cumulative proportion of patients returning to baseline reactivity after study drug discontinuation. A total of 56 patients were randomized; 54 were eligible for analysis. Platelet reactivity was lower 24 h after the last dose of prasugrel compared with clopidogrel. After prasugrel, ≥75% of patients returned to baseline reactivity by washout day 7 compared with day 5 after clopidogrel. Recovery time was dependent on the level of platelet reactivity before study drug exposure and the initial degree of platelet inhibition after study drug discontinuation but not on treatment assignment. Recovery time after thienopyridine discontinuation depends on the magnitude of on-treatment platelet inhibition, resulting, on average, in a more delayed recovery with prasugrel compared with clopidogrel. The offset of prasugrel was consistent with current guidelines regarding the recommended waiting period for surgery after discontinuation. (Prasugrel/Clopidogrel Maintenance Dose Washout Study; NCT01014624).
    Journal of the American College of Cardiology 06/2012; 59(25):2338-43. · 14.09 Impact Factor
  • Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2011; 57(14).