Background: ODYSSEY Outcomes is a randomized, double-blind, placebo-controlled, parallel-group study to evaluate the effect of alirocumab (SAR236553/REGN727) on the occurrence of cardiovascular events in patients who have recently experienced an acute coronary syndrome (ACS). This multicenter phase 3 study has randomized approximately 18’000 patients to receive biweekly injections of alirocumab (75-150 mg) or matching placebo in addition to standard high effective statin therapy. Qualifying patients fulfill one of the following criteria: LDL-C ≥ 1.81 mmol/L, non-high-density lipoprotein cholesterol ≥ 2.59 mmol/L, or apolipoprotein B ≥ 80 mg/dL. The ODYSSEY Outcomes trial tests the hypothesis that treatment with alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), improves cardiovascular outcomes after ACS. Trial Registration No: NCT01663402 (clinicaltrials.gov) Link Trial Status: completed Enrolling Centers: Worldwide: multicentric Core Study Team: