Pharmacodynamic Evaluation of Switching From Ticagrelor to Prasugrel in Subjects With Stable Coronary Artery Disease

This is a Phase 4, multicenter, open-label (blinded Pharmacodynamic PD results), randomized, 3-arm, parallel-design study of subjects with stable Coronary Artery Disease CAD. This study will compare the PD effect of prasugrel 10 mg QD (once-daily) maintenance dose with ticagrelor 90 mg BID (twice daily) maintenance dose in subjects with stable CAD who have previously received ticagrelor loading does (LD) and maintenance dose (MD)..


Eligibility Criteria:
Inclusion Criteria:

* Male or female; age \>= 18 and \< 75 years
* Weight \>= 60 kg
* Receiving low dose ASA (75 mg to 150 mg daily) for at least 7 days at the time of Visit 1 and able to continue the same regimen throughout the study
* Stable CAD. CAD is defined as any of the following:
* History of a positive stress test
* Previous coronary revascularization including percutaneous coronary intervention (PCI), stent, or coronary artery bypass graft (CABG)
* Angiographic demonstration of CAD (at least

  1 lesion \>= 50 percent)
* Presence of at least moderate plaque by computed tomography (CT) angiography
* Electron beam CT coronary artery calcification score \>= 100 Agatston units
* If female, may be enrolled if

One of the following 3 criteria are met:

* Had a hysterectomy or tubal ligation at least 6 months prior to signing the informed consent form (ICF)
* Post-menopausal for at least 1 year
* If of childbearing potential, will practice 1 of the following methods of birth control throughout the study: oral, injectable, or implantable hormonal contraceptives; intrauterine device; diaphragm plus spermicide; or female condom plus spermicide. Methods of contraception that are not acceptable are partner's use of condoms or partner's vasectomy
* Able and willing to provide written informed consent before entering the study

Exclusion Criteria:

* Have a defined need for adenosine diphosphate (ADP)-receptor inhibitor therapy, such as any of the following (or any other condition that in the Investigator's judgment would require such therapy):
* Within =\< 12 months of an acute coronary syndrome (ACS) event (unstable angina \[UA\], non-ST-elevation myocardial infarction \[NSTEMI\], or ST-elevation myocardial infarction \[STEMI\]) regardless of initial treatment (that is, invasive versus noninvasive)
* Subjects who underwent angioplasty within 12 months including bare-metal stent and/or a drug-eluting stent
* Had any stent placed in an unprotected left main coronary artery or in the last patent artery within the last 12 months
* Received thienopyridine therapy within 30 days of study entry
* Plan to undergo coronary revascularization at any time during the trial
* Presence or history of any of the following: ischemic or hemorrhagic stroke; transient ischemic attack (TIA); intracranial neoplasm; arteriovenous malformation, or aneurysm; intracranial hemorrhage; head trauma (within 3 months of study entry)
* History of refractory ventricular arrhythmias with an increased risk of bradycardic events (eg, subjects without a pacemaker who have sick sinus syndrome, 2nd or 3rd degree atrioventricular (AV) block or bradycardic-related syncope)
* History or evidence of congestive heart failure (New York Heart Association Class III or above =\< 6 months before screening
* Severe hepatic impairment
* History of uric acid nephropathy
* Uncontrolled hypertension, or systolic blood pressure \> 180 mmHg or diastolic blood pressure \> 110 mmHg at screening
* Severely impaired renal function (glomerular filtration rate \< 30 mL/minute) or on dialysis
* At risk for bleeding
* Taking prohibited medications