November 18, 2009 – Patient enrollment was recently completed in the TRA 2 P-TIMI 50 clinical trial to study SCH 530348, an investigational anti-platelet protease activated receptor-1 (PAR-1) inhibitor.
The study, conducted by the Thrombolysis in Myocardial Infarction (TIMI) Study Group, reached its target of more than 26,000 patients. The phase III, randomized, double-blind, placebo-controlled, multinational study will assess the ability of SCH 530348 to prevent major cardiovascular events when added to current anti-platelet regimens (aspirin or aspirin + ADP inhibitor) in patients who have previously experienced a heart attack or stroke or who have peripheral arterial disease.
“TIMI 50 is the largest and most rapidly enrolling trial in our 25-year history,” said Eugene Braunwald, M.D., chairman of the TIMI Study Group. “We are very pleased with this achievement and look forward to completing this important clinical outcome trial.”
SCH 530348, developed by Merck, is also being studied in the treatment of patients with acute coronary syndrome (ACS) in the ongoing Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRA-CER) trial, led by Duke Clinical Research Institute.
SCH 530348 binds selectively to the thrombin receptor on platelets (PAR-1), and is therefore a member of a potentially new class of drugs called PAR-1 inhibitors. It is being investigated to determine whether it has the potential to provide clinical benefit through inhibition of this thrombin-mediated platelet activation without the liability of significantly increased major bleeding (when added to aspirin or aspirin plus an ADP inhibitor), a tendency associated with drugs that block thromboxane or ADP pathways. Specifically, this compound is being investigated as an oral anti-platelet agent for patients with established vascular disease, to evaluate whether it can provide incremental benefit when given with current standard anti-platelet (including aspirin and clopidogrel) and other anti-thrombotic therapies, without causing a significant increase in major bleeding.
The 1,030-patient TRA-PCI Phase II trial was published in the March 14, 2009 issue of The Lancet.
The U.S. Food and Drug Administration (FDA) has granted fast track designation to the compound, which allows the FDA to expedite review of drugs for serious or life-threatening conditions that demonstrate the potential to address unmet medical needs.
For more information: visit www.merck.com
November 12, 2025 
