Recombinant human lecithin-cholesterol acyltransferase in patients with atherosclerosis: phase 2a primary results and phase 2b design.

AIMS: Reverse cholesterol transport (RCT) removes cholesterol and stabilizes vulnerable plaques. In addition, high-density lipoprotein (HDL) may be cardioprotective in acute myocardial infarction (MI). Lecithin-cholesterol acyltransferase (LCAT) may enhance RCT. The objective of this study was to investigate the pharmacokinetics, pharmacodynamics, and safety of multiple ascending doses of recombinant human LCAT (MEDI6012) to inform a Phase 2b programme. METHODS AND RESULTS: This was a randomized, blinded, placebo-controlled, dose-escalation Phase 2a study of MEDI6012. Patients were randomized into one of four cohorts (40, 120, 300 mg IV weekly ×3 doses, or 300 mg IV-push, 150 mg at 48 h and 100 mg at 7 days). All cohorts were planned to randomize 6:2 (MEDI6012 vs. placebo). The primary endpoints were baseline-adjusted area under the curve (AUC) from 0 to 96 h post dose 3 (AUC 0-96 h) for HDL-C, HDL cholesteryl ester (HDL-CE), and total cholesteryl ester (CE). The primary safety endpoints were treatment-emergent adverse events. A total of 32 patients were randomized. MEDI6012 significantly increased AUC 0-96 h for HDL-C, HDL-CE and CE in a graded fashion with increasing doses. Relative to placebo, MEDI6012 increased HDL-C at Day 19 by 66% (95% CI 33-99, P = 0.014) with 120 mg and 144% (95% CI 108-181, P < 0.001) with 300 mg. An IV-push increased HDL-C by 40.8% at 30 min. Overall adverse events were similar between groups with no severe, life-threatening/fatal adverse events, or neutralizing antibodies. CONCLUSIONS: Multiple ascending doses of MEDI6012 were safe and well tolerated and significantly increased HDL-C, HDL-CE and CE in a dose-related manner. These data support the ongoing Phase 2b programme investigating MEDI6012 in ST-elevation MI.

Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction: The AEGIS-I Trial (ApoA-I Event Reducing in Ischemic Syndromes I).

BACKGROUND: Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein-mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction. METHODS: The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy). RESULTS: A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events among the groups was similar. CONCLUSIONS: Among patients with acute myocardial infarction, 4 weekly infusions of CSL112 are feasible, well tolerated, and not associated with any significant alterations in liver or kidney function or other safety concern. The ability of CSL112 to acutely enhance cholesterol efflux was confirmed. The potential benefit of CSL112 to reduce major adverse cardiovascular events needs to be assessed in an adequately powered phase 3 trial. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02108262.

Lipoprotein oxidation and its significance for atherosclerosis: a mathematical approach.

Atherosclerosis is a chronic disease which involves the build up of cholesterol and fatty deposits within the arterial wall. This results in the narrowing of the vessel lumen, which eventually restricts blood flow to vital organs such as the heart and lungs. These events may culminate in a heart attack or stroke, the commonest causes of death in the U.K. population. In this paper we study the early stages of atherosclerosis which include the build up of cholesterol within subendothelial cells to form what is known as a fatty streak, the earliest identifiable evidence of atherosclerosis. The deposition of cholesterol is believed to be a consequence of oxidation of circulating cholesterol-rich lipoproteins, in particular low density lipoproteins (LDLs). Via a mathematical model we investigate this process of oxidation within the context of an in vitro framework. We first recreate existing experimental results and then extend the model to investigate phenomenon not studied by current experimental protocols. We find that the model displays hysteresis which reveals some interesting insights into possible in vivo events. Mathematical analysis of this behaviour predicts that vitamin E supplementation is not as beneficial as high density lipoproteins (HDLs) and vitamin C. Furthermore, the scavenging of oxidants by HDL can provide an important first line of defence against LDL oxidation.