This Phase IV, multicenter trial is designed to assess the efficacy of prasugrel in preventing the formation of blood clots in Taiwanese patients with ACS who have been treated with PCI.

Inclusion Criteria:

• Is within the age limits and has signed informed consent

• Weighs at least 50 kg

• Had a previous diagnosis of ACS (UA, STEMI, or NSTEMI), underwent PCI, and received one of the following treatments:

  • Clopidogrel MD of 75 mg and aspirin 81-100 mg for 2-8 weeks following clopidogrel loading dose (LD) of 300 mg or 600 mg at the time of PCI
  • Ticagrelor MD of 90 mg twice daily (BID) and aspirin 81-100 mg for 1-4 weeks and switching to clopidogrel MD of 75 mg and aspirin 81-100 mg for 2-4 weeks following ticagrelor LD of 180 mg at the time of PCI
  • Clopidogrel MD 75 mg and aspirin 81-100 mg for 2-8 weeks following ticagrelor LD of 180 mg at the time of PCI
  • Or based on investigator's judgment with at least 2 weeks continued use of clopidogrel MD and aspirin 81-100 mg per day before switching to prasugrel and maximum 8 weeks P2Y12 inhibitors MD treatment (prasugrel is not allowed)

• Is willing and able to abide by the rules of the research unit and study restrictions

• If a woman of child-bearing potential, has a negative serum pregnancy test at screening

• Agrees to use at least one method of contraception during the study

Exclusion Criteria:

• Has active bleeding, significant risk of hemorrhage, or unusual susceptibility to bleed
• Had previous hemorrhagic stroke at any time, or transient ischemic attack (TIA) or ischemic stroke within 3 months before the informed consent date
• Has known allergies or hypersensitivity to prasugrel, aspirin, or any of their excipients
• Has significant hypertension at screening or baseline assessment
• Has hemoglobin levels <10.5 g/dL or hematocrit levels <30%
• Has severe left ventricular systolic dysfunction, ejection fraction <30%
• Is currently undergoing hemodialysis
• Has evidence of severe hepatic disease or any of the following: serum alanine transaminase or aspartate transaminase ≥3 times the upper limit of normal (ULN); or bilirubin ≥2 times the ULN at screening
• Has any clinical laboratory result performed at screening that is determined to be detrimental to the patient or could compromise the study as determined the Investigator
• Has previously participated in this study or in another interventional trial that is not compatible with this study
• Has evidence of significant active neuropsychiatric disease, alcohol abuse or drug abuse as determined by the Investigator

De-identified individual participant data (IPD) and applicable supporting clinical trial documents may be available upon request at https://vivli.org/. In cases where clinical trial data and supporting documents are provided pursuant to our company policies and procedures, Daiichi Sankyo will continue to protect the privacy of our clinical trial participants. Details on data sharing criteria and the procedure for requesting access can be found at this web address: https://vivli.org/ourmember/daiichi-sankyo/

Studies for which the medicine and indication have received European Union (EU) and United States (US), and/or Japan (JP) marketing approval on or after 01 January 2014 or by the US or EU or JP Health Authorities when regulatory submissions in all regions are not planned and after the primary study results have been accepted for publication.

Formal request from qualified scientific and medical researchers on IPD and clinical study documents from clinical trials supporting products submitted and licensed in the United States, the European Union and/or Japan from 01 January 2014 and beyond for the purpose of conducting legitimate research. This must be consistent with the principle of safeguarding study participants' privacy and consistent with provision of informed consent.