New Study Shows Prasugrel Achieves Faster Onset And Higher Levels Of Platelet Inhibition Than Clopidogrel At Approved Or Higher Doses
Thirty minutes after oral administration, the level of platelet inhibition with a prasugrel 60 mg dose was significantly higher than observed with either loading dose of clopidogrel. At one hour, the antiplatelet inhibition achieved with a prasugrel loading dose was greater than that seen at up to six hours following administration of the approved and high loading doses of clopidogrel.
"This data shows for the first time that as early as 30 minutes after dosing, a 60 mg prasugrel loading dose achieves greater platelet inhibition than both the approved loading dose and high-dose clopidogrel," said Kenneth Winters, M.D., Lilly research cardiologist.
In an earlier Phase I study with healthy volunteers, a 60 mg loading dose of prasugrel showed a lower rate of poor responders by platelet function testing compared with the approved 300 mg loading dose of clopidogrel. Poor responders are defined as those who fail to reach a specified level of platelet inhibition after receiving the drug. Findings showed poor antiplatelet response in 17 percent to 43 percent of those given the approved clopidogrel loading dose (depending on the definition of poor responder used); while no poor responders were observed with prasugrel.
Winters presented the new clinical data today in an oral presentation at the Cardiovascular Research Foundation's 18th annual Transcatheter Cardiovascular Therapeutics meeting in Washington, D.C. Data from the other Phase I study appeared in a poster presentation at the meeting.
Daiichi Sankyo and Lilly are currently studying prasugrel in the Phase III head-to-head clinical trial TRITON-TIMI 38. The TRITON-TIMI 38 study will evaluate the safety and efficacy of prasugrel compared with clopidogrel in reducing ischemic events such as heart attacks, stroke and death in approximately 14,000 patients with acute coronary syndrome undergoing percutaneous coronary intervention, including coronary stenting. The study is expected to be completed in 2007, and, if successful, regulatory submissions will follow in the same year.
About the studies
In the Phase I study, "Inhibition of Platelet Aggregation Following Loading and Maintenance Dose Administration of 60/10 mg Prasugrel, 300/75 mg and 600/75 mg Clopidogrel In Healthy Subjects," loading and maintenance doses of prasugrel (60 mg and 10 mg, respectively) were compared with 600 mg and 300 mg clopidogrel loading doses (both given with the approved clopidogrel 75 mg maintenance dose) in a three-period crossover study in 41 aspirin-free healthy subjects. A seven-day maintenance dose schedule followed the loading dose, followed by a 14-day washout period before the next treatment period. Researchers used turbidometric aggregometry, considered the gold standard of testing platelet function, to measure the inhibition of platelet aggregation (IPA) to 20 micron ADP.
The study used a crossover design in which the same individuals received each of the three medication regimens, on three separate occasions, allowing researchers to compare in each individual the antiplatelet response of prasugrel to either 300 mg or 600 mg clopidogrel.
Thirty minutes following initial oral administration of a 60 mg prasugrel loading dose, inhibition of platelet aggregation (IPA, to 20 micron ADP) was significantly higher at 52.1 percent, compared with 4.3 percent for clopidogrel 600 mg (p
New studiul aratã Prasugrel realizeazã mai rapid debut ªi niveluri mai ridicate de inhibarea trombocitelor Than Clopidogrel La aprobate sau doze mai mari - New Study Shows Prasugrel Achieves Faster Onset And Higher Levels Of Platelet Inhibition Than Clopidogrel At Approved Or Higher Doses - articole medicale engleza - startsanatate