Impacts of CYP2C19 genetic polymorphisms on bioavailability and effect on platelet adhesion of vicagrel, a novel thienopyridine P2Y12 inhibitor.

AIM: We investigated the impacts of CYP2C19 polymorphisms on pharmacokinetics and pharmacodynamics of vicagrel in healthy Chinese subjects. METHODS: CYP2C19 extensive metabolizers (EMs), intermediate metabolizers (IMs), and poor metabolizers (PMs) (18 subjects/group) participated in a randomized, open-label, two-period cross-over study. Each study period lasted 7 days, with a loading dose of 24 mg of vicagrel or 300 mg of clopidogrel on day 1, and maintenance doses of 6 mg of vicagrel or 75 mg of clopidogrel daily from day 2 to day 7. The pharmacokinetics and pharmacodynamics were assessed on day 1 and day 7. RESULTS: After a loading dose, the AUC0-t of the active metabolite H4 by vicagrel was slightly lower in IMs and PMs (decreased by 21% and 27%, respectively) compared to EMs. Similar results were found after maintenance doses. In EMs, the AUC0-t of H4 by vicagrel was somewhat higher than clopidogrel after the loading dose, and comparable with clopidogrel (90% CI 0.94, 1.21) after the maintenance doses. However, it was much higher than clopidogrel in PMs, with a 1.28-fold (loading dose) and a 73% (maintenance doses) increases compared to clopidogrel (P < 0.001). Consequently, the IPA by vicagrel was greater than clopidogrel after both loading dose (28.2% vs. 12.4% at 4 h, P < 0.01) and maintenance doses (42.8% vs. 24.6% at 4 h, P < 0.001) in PMs. CONCLUSIONS: CYP2C19 polymorphisms have less impact on vicagrel as compared to clopidogrel. Drug exposure and response to vicagrel in PMs were even higher than to clopidogrel in IMs.