Prasugrel 5-mg in the very elderly attenuates platelet inhibition but maintains non-inferiority to prasugrel 10-mg in non-elderly patients: The GENERATIONS trial, a pharmacodynamic and pharmacokinetic study in stable coronary artery disease patients

• Published in: Journal of the American College of Cardiology Vol. 62; no. 7; p. 577
• Main Authors: Erlinge, David, Gurbel, Paul A, James, Stefan, Lindahl, Tomas L, Svensson, Peter, Ten Berg, Jurrien M, Foley, David P, Wagner, Henrik, Brown, Patricia B, Luo, Junxiang, Zhou, Chunmei, Moser, Brian A, Jakubowski, Joseph A, Small, David S, Winters, Kenneth J, Angiolillo, Dominick J
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: Cardiac and Cardiovascular Systems; Cardiology and Cardiovascular Disease; Clinical Medicine; Kardiologi; Kardiologi och kardiovaskulära sjukdomar; Klinisk medicin; Medical and Health Sciences; Medicin och hälsovetenskap
• ISSN: 0735-1097
• DOI: 10.1016/j.jacc.2013.05.023

OBJECTIVES: We assessed pharmacodynamic (PD) response for the reduced prasugrel 5-mg maintenance dose in very elderly (≥75y; VE) patients. BACKGROUND: In TRITON-TIMI 38, prasugrel 10-mg reduced ischemic events versus clopidogrel 75-mg, but increased bleeding in VE patients. METHODS: We examined PD and active-metabolite pharmacokinetics with prasugrel 5-mg and 10-mg and clopidogrel 75-mg in a three-period (12 days each), blinded, cross-over study in VE (n=73, mean 79±3y) or non-elderly (≥45-<65y, NE) (n=82, 56±5y) stable coronary artery disease (CAD) patients on background aspirin. Assays included light transmission aggregometry (LTA), VerifyNow(®) P2Y12 (VN-P2Y12), and VASP. The primary comparison was non-inferiority of maximum platelet aggregation (MPA) comparing the median for prasugrel 5-mg in VE versus the 75th percentile for prasugrel 10-mg in NE, using a prespecified one-sided 97.5% confidence interval for the difference <15%. RESULTS: Prasugrel 5-mg in VE met the primary pharmacodynamic non-inferiority criterion versus prasugrel 10-mg in NE. For prasugrel 5-mg, MPA was significantly lower (mean±SD, 57±14%) than clopidogrel (63±14%) (p<0.001) in VE, but higher than prasugrel 10-mg in NE (46±12%) (p<0.001). PD response by LTA, VN-P2Y12, and VASP during all treatments appeared similar between age cohorts. Prasugrel 5-mg resulted in fewer VE poor responders versus clopidogrel. Rates of mild bleeding were higher with prasugrel 10-mg, but similar for prasugrel 5-mg versus clopidogrel 75-mg. CONCLUSIONS: In aspirin-treated stable CAD patients, prasugrel 5-mg in VE attenuated platelet inhibition while meeting prespecified non-inferiority criterion versus prasugrel 10-mg in NE, with significantly better PD response and fewer poor responders compared to clopidogrel 75-mg in VE.