A Study to Evaluate the Safety and Efficacy of MEDI6012 in Acute ST Elevation Myocardial Infarction

Left Ventricular Ejection Fraction (LVEF)

The LVEF measured by cine magnetic resonance imaging (MRI) at 10-12 weeks post-MI is reported.

Time frame: 70 to 84 days post Day 1 dose

Change in Non-calcified Plaque Volume (NCPV) in the Coronary Arteries in Cohort B

Change in NCPV in the coronary arteries from index computed tomography angiography (CTA) to 10-12 weeks post-MI is reported. The index CTA was preferably to be performed between 48 to 72 hours post Dose 1 (could be done up to 5 days post Dose 1) but no earlier than 40 hours post Dose 1. Participants with creatinine clearance \>= 60 mL/min (Cockcroft Gault equation) within 6 hours underwent an index coronary CTA no earlier than 40 hours following the first dose.

Time frame: Day 1 dose (48 to 72 hours post Dose 1) through 70 to 84 days post Day 1 dose

Left Ventricular Mass by Late Gadolinium Enhancement (LGE)

The left ventricular mass by LGE is reported.

Time frame: 70 to 84 days post Day 1 dose

Left Ventricular Mass by Cine Magnetic Resonance Imaging (MRI)

The left ventricular mass by cine MRI is reported.

Time frame: 70 to 84 days post Day 1 dose

Left Ventricular End-diastolic and End-systolic Volume

Left ventricular end-diastolic and end-systolic volume is reported.

Time frame: 70 to 84 days post Day 1 dose

Left Ventricular End-diastolic and End-systolic Volume Index

Left ventricular end-diastolic and end-systolic volume index is reported.

Time frame: 70 to 84 days post Day 1 dose

Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (TESAEs)

An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. A serious adverse event (SAE) is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug.

Time frame: Day 1 through Day 195 post Day 1 dose

Serum Concentration of MEDI6012 (Lecithin-cholesterol Acyltransferaes [LCAT] Mass)

Serum concentration of MEDI6012 is reported.

Time frame: Pre- and post-dose on Days 1, 3, 17, and 31

Number of Participants With Positive Anti-Drug Antibodies (ADA) to MEDI6012

Number of participants with positive ADA titer to MEDI6012 are reported in 3 categories, ADA positive at any visit up to Day 70-84 follow-up visit, ADA positive with \> 30% decrease in HDL-C from baseline (on the same date) at any visit up to D70-84 FU V, and ADA positive and \> 30% decrease in HDL-C from baseline at Day 70-84 Follow-up Visit.

Time frame: Predose on Day 1, Day 17, Day 31, 70 to 84 days, and on Day 195 post Day 1 dose