Julie Butters

Effect of serial infusions of reconstituted high-density lipoprotein (CER-001) on coronary atherosclerosis: Rationale and design of the CARAT study

BACKGROUND High-density lipoprotein (HDL) is believed to have atheroprotective properties, but an effective HDL-based therapy remains elusive. Early studies have suggested that infusion of reconstituted HDL promotes reverse cholesterol transport and vascular reactivity. The CER-001 Atherosclerosis Regression Acute Coronary Syndrome Trial (CARAT) is investigating the impact of infusing an engineered pre-beta HDL mimetic containing sphingomyelin (SM) and dipalmitoyl phosphatidlyglycerol (CER-001) on coronary atheroma volume in patients with a recent acute coronary syndrome (ACS). METHODS The CARAT is a phase 2, multicenter trial in which 292 patients with an ACS undergoing intracoronary ultrasonography and showing percent atheroma volume (PAV) greater than 30% are randomly assigned to treatment with ten infusions of CER-001 3 mg/kg or matching placebo, administered at weekly intervals. Intracoronary ultrasonography is repeated at the end of the treatment period. RESULTS The primary endpoint is the nominal change in PAV. Safety and tolerability will also be evaluated. CONCLUSIONS CARAT will establish whether serial 3 mg/kg infusions of an engineered pre-beta HDL mimetic containing SM and dipalmitoyl phosphatidlyglycerol (CER-001) will regress atherosclerotic plaque in patients with a recent ACS.

Regression of coronary atherosclerosis with infusions of the high-density lipoprotein mimetic CER-001 in patients with more extensive plaque burden

BACKGROUND CER-001 is an engineered pre-beta high-density lipoprotein (HDL) mimetic, which rapidly mobilizes cholesterol. Infusion of CER-001 3 mg/kg exhibited a potentially favorable effect on plaque burden in the CHI-SQUARE (Can HDL Infusions Significantly Quicken Atherosclerosis Regression) study. Since baseline atheroma burden has been shown as a determinant for the efficacy of HDL infusions, the degree of baseline atheroma burden might influence the effect of CER-001. METHODS CHI-SQUARE compared the effect of 6 weekly infusions of CER-001 (3, 6 and 12 mg/kg) vs. placebo on coronary atherosclerosis in 369 patients with acute coronary syndrome (ACS) using serial intravascular ultrasound (IVUS). Baseline percent atheroma volume (B-PAV) cutoff associated with atheroma regression following CER-001 infusions was determined by receiver-operating characteristics curve analysis. 369 subjects were stratified according to the cutoff. The effect of CER-001 at different doses was compared to placebo in each group. RESULTS A B-PAV ≥30% was the optimal cutoff associated with PAV regression following CER-001 infusions. CER-001 induced PAV regression in patients with B-PAV ≥30% but not in those with B-PAV <30% (-0.45%±2.65% vs. +0.34%±1.69%, P=0.01). Compared to placebo, the greatest PAV regression was observed with CER-001 3mg/kg in patients with B-PAV ≥30% (-0.96%±0.34% vs. -0.25%±0.31%, P=0.01), whereas there were no differences between placebo (+0.09%±0.36%) versus CER-001 in patients with B-PAV <30% (3 mg/kg; +0.41%±0.32%, P=0.39; 6 mg/kg; +0.27%±0.36%, P=0.76; 12 mg/kg; +0.32%±0.37%, P=0.97). CONCLUSIONS Infusions of CER-001 3 mg/kg induced the greatest atheroma regression in ACS patients with higher B-PAV. These findings identify ACS patients with more extensive disease as most likely to benefit from HDL mimetic therapy.

Effect of Serial Infusions of CER-001, a Pre-β High-Density Lipoprotein Mimetic, on Coronary Atherosclerosis in Patients Following Acute Coronary Syndromes in the CER-001 Atherosclerosis Regression Acute Coronary Syndrome Trial: A Randomized Clinical Trial

Importance CER-001 is a negatively charged, engineered pre-&bgr; high-density lipoprotein (HDL) mimetic containing apolipoprotein A-I and sphingomyelin. Preliminary studies demonstrated favorable effects of CER-001 on cholesterol efflux and vascular inflammation. A post hoc reanalysis of a previously completed study of intravenous infusion of CER-001, 3 mg/k, showed that the intravenous infusion in patients with a high coronary plaque burden promoted regression as assessed by intravascular ultrasonography. Objective To determine the effect of infusing CER-001 on coronary atherosclerosis progression in statin-treated patients. Design, Setting, and Participants A double-blind, randomized, multicenter trial evaluating the effect of 10 weekly intravenous infusions of CER-001, 3 mg/kg, (n = 135) or placebo (n = 137) in patients with an acute coronary syndrome (ACS) and baseline percent atheroma volume (PAV) greater than 30% in the proximal segment of an epicardial artery by intravascular ultrasonography. The study included 34 academic and community hospitals in Australia, Hungary, the Netherlands, and the United States in patients with ACS presenting for coronary angiography. Patients were enrolled from August 15, 2015, to November 19, 2016. Interventions Participants were randomized to receive weekly CER-001, 3 mg/kg, or placebo for 10 weeks in addition to statins. Main Outcomes and Measures The primary efficacy measure was the nominal change in PAV from baseline to day 78 measured by serial intravascular ultrasonography imaging. The secondary efficacy measures were nominal change in normalized total atheroma volume and percentage of patients demonstrating plaque regression. Safety and tolerability were also evaluated. Results Among 293 patients (mean [SD] age, 59.8 [9.4] years; 217 men [79.8%] and 261 white race/ethnicity [96.0%]), 86 (29%) had statin prior use prior to the index ACS and 272 (92.8%) had evaluable imaging at follow-up. The placebo and CER-001 groups had similar posttreatment median levels of low-density lipoprotein cholesterol (74 mg/dL vs 79 mg/dL; P = .15) and high-density lipoprotein cholesterol (43 mg/dL vs 44 mg/dL; P = .66). The primary efficacy measure, PAV, decreased 0.41% with placebo (P = .005 compared with baseline), but not with CER-001 (−0.09%; P = .67 compared with baseline; between group differences, 0.32%; P = .15). Similar percentages of patients in the placebo and CER-001 groups demonstrated regression of PAV (57.7% vs 53.3%; P = .49). Infusions were well tolerated, with no differences in clinical and laboratory adverse events observed between treatment groups. Conclusions and Relevance Infusion of CER-001 did not promote regression of coronary atherosclerosis in statin-treated patients with ACS and high plaque burden. Trial Registration ClinicalTrials.gov Identifier: NCT2484378

Clinical Outcomes in Trials Evaluating Lipid-Lowering Drugs

While statins have formed the cornerstone of strategies for cardiovascular prevention, the residual risk related to low-density lipoprotein cholesterol (LDL-C) and other lipoprotein factors provides a landscape for development of new therapies. However, a number of lipid-modifying therapies have failed to reduce cardiovascular event rates in contemporary clinical trials of statin-treated patients. The factors considered in outcome measure selection for clinical trials of novel lipid-lowering therapies are reviewed. Evaluation of lipid-modifying drugs in clinical trials spans a spectrum from their effects on conventional circulating lipid parameters through to their impact on atherosclerotic plaque and ultimately clinical outcomes. The design of these trials has an important impact on the result and ultimate interpretation of these studies.