Efficacy of FX06 in the Prevention of Myocardial Reperfusion Injury

Inclusion Criteria: * Patients who have given informed consent * Patients after primary percutaneous coronary intervention (PCI) for acute ST-elevation myocardial infarction (STEMI) * Men or women with no child bearing potential * Onset of symptoms to balloon time \< 6 hours * ST-elevation of at least 2 mm in at least 3 leads on 12-lead electrocardiogram (ECG) * Primary PCI indicated per standard of care * First myocardial infarction (MI) * Single index lesion with complete occlusion \[thrombolysis in myocardial infarction (TIMI) flow 0/I\] of one target vessel. Exclusion Criteria: * History of MI (from patient history, or from ECG) * Chest pain or other angina symptoms in the 24 hours before the first recognized symptoms of the acute myocardial infarction (AMI) * Need for coronary artery bypass graft (CABG) * Administration of any thrombolytic agent since onset of AMI symptoms * Serious procedural complications (e.g., procedural unintended occlusion of coronary artery branch, cardiac tamponade, emergency bypass operation, LM dissection, etc.) * Presence of cardiogenic shock: hemodynamically unstable and/or need for positive inotropic agents * Contraindication to cardiovascular magnetic resonance (CMR): claustrophobia, pacemakers, defibrillators and other electronic devices, and metallic cerebral clips; frequent extrasystoles (\> 12/Min) or atrial fibrillation (AF). * Known renal dysfunction defined as serum creatinine \> 250 µmol/l * Previous CABG * History of congestive heart failure (CHF) * Body mass index (BMI) \> 35 * Patients who cannot communicate reliably with the investigator * Patients who are unlikely to cooperate with the requirements of the study * Patients who are unwilling and/or unable to give informed consent * Patients at increased risk of death from a pre-existing concurrent illness * Patients participating in another clinical study * Patients who have used any other investigational drugs within 1 month of first dosing * Patients who have participated already in this study * Patients who are employees at the investigational site; relatives or spouse of the investigator.