Poulabi Banerjee

Genetic and Pharmacologic Inactivation of ANGPTL3 and Cardiovascular Disease

BACKGROUND Loss‐of‐function variants in the angiopoietin‐like 3 gene (ANGPTL3) have been associated with decreased plasma levels of triglycerides, low‐density lipoprotein (LDL) cholesterol, and high‐density lipoprotein (HDL) cholesterol. It is not known whether such variants or therapeutic antagonism of ANGPTL3 are associated with a reduced risk of atherosclerotic cardiovascular disease. METHODS We sequenced the exons of ANGPTL3 in 58,335 participants in the DiscovEHR human genetics study. We performed tests of association for loss‐of‐function variants in ANGPTL3 with lipid levels and with coronary artery disease in 13,102 case patients and 40,430 controls from the DiscovEHR study, with follow‐up studies involving 23,317 case patients and 107,166 controls from four population studies. We also tested the effects of a human monoclonal antibody, evinacumab, against Angptl3 in dyslipidemic mice and against ANGPTL3 in healthy human volunteers with elevated levels of triglycerides or LDL cholesterol. RESULTS In the DiscovEHR study, participants with heterozygous loss‐of‐function variants in ANGPTL3 had significantly lower serum levels of triglycerides, HDL cholesterol, and LDL cholesterol than participants without these variants. Loss‐of‐function variants were found in 0.33% of case patients with coronary artery disease and in 0.45% of controls (adjusted odds ratio, 0.59; 95% confidence interval, 0.41 to 0.85; P=0.004). These results were confirmed in the follow‐up studies. In dyslipidemic mice, inhibition of Angptl3 with evinacumab resulted in a greater decrease in atherosclerotic lesion area and necrotic content than a control antibody. In humans, evinacumab caused a dose‐dependent placebo‐adjusted reduction in fasting triglyceride levels of up to 76% and LDL cholesterol levels of up to 23%. CONCLUSIONS Genetic and therapeutic antagonism of ANGPTL3 in humans and of Angptl3 in mice was associated with decreased levels of all three major lipid fractions and decreased odds of atherosclerotic cardiovascular disease. (Funded by Regeneron Pharmaceuticals and others; ClinicalTrials.gov number, NCT01749878.)

Effect of PCSK9 Inhibition by Alirocumab on Lipoprotein Particle Concentrations Determined by Nuclear Magnetic Resonance Spectroscopy

Background In patients with discordance between low‐density lipoprotein (LDL) cholesterol and LDL particle (LDL‐P) concentrations, cardiovascular risk more closely correlates with LDL−P. Methods and Results We investigated the effect of alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9, on lipoprotein particle concentration and size in hypercholesterolemic patients, using nuclear magnetic resonance spectroscopy. Plasma samples were collected from patients receiving alirocumab 150 mg every 2 weeks (n=26) or placebo (n=31) during a phase II, double‐blind, placebo‐controlled trial in patients (LDL cholesterol ≥100 mg/dL) on a stable atorvastatin dose. In this post hoc analysis, percentage change in concentrations of LDL−P, very‐low‐density lipoprotein particles, and high‐density lipoprotein particles from baseline to week 12 was determined by nuclear magnetic resonance. Alirocumab significantly reduced mean concentrations of total LDL‐P (−63.3% versus −1.0% with placebo) and large (−71.3% versus −21.8%) and small (−54.0% versus +17.8%) LDL‐P subfractions and total very‐low‐density lipoprotein particle concentrations (−36.4% versus +33.4%; all P<0.01). Total high‐density lipoprotein particles increased with alirocumab (+11.2% versus +1.4% with placebo; P<0.01). There were greater increases in large (44.6%) versus medium (17.7%) or small high‐density lipoprotein particles (2.8%) with alirocumab. LDL‐P size remained relatively unchanged in both groups; however, very‐low‐density and high‐density lipoprotein particle sizes increased to a significantly greater extent with alirocumab. Conclusions Alirocumab significantly reduced LDL‐C and LDL‐P concentrations in hypercholesterolemic patients receiving stable atorvastatin therapy. These findings may be of particular relevance to patients with discordant LDL‐C and LDL‐P concentrations. Clinical Trial Registration URL: https://clinicaltrials.gov. Unique identifier: NCT01288443.

ANGPTL3 Inhibition in Homozygous Familial Hypercholesterolemia

Evinacumab, a monoclonal antibody that blocks ANGPTL3, was administered to nine adults with homozygous familial hypercholesterolemia. At 4 weeks, LDL cholesterol was reduced by a mean of 49%, with a mean absolute change from baseline of −157 mg per deciliter.

Plasma levels of amyloid beta and other proinflammatory mediators in patients with age-related macular degeneration

PurposeTo investigate the plasma levels of amyloid beta (Aβ) and select inflammatory mediators in patients with various stages of AMD compared to that of age-matched controls, and discern a relationship to disease severity.MethodsPlasma samples were obtained from AMD subjects at various stages of disease—early (drusen only), geographic atrophy (GA), neovascular AMD (CNV)—and from controls of similar age without AMD. Samples were analyzed using a commercially available ELISA kit (sixteen cytokines) or LC/MS/MS (Aβ isotypes). Descriptive statistics were compiled on all analytes. Analysis of covariance (ANCOVA) was conducted to compare each analyte across AMD groups while adjusting for sex and age of the patients, and in comparison to the control group. Receiver operating characteristics plots were generated for the strongest predictor variables.ResultsLevels of alternative spliced CC3 proteins were significantly different between controls and CNV groups (p < 0.05), with median levels almost twice higher in CNV than in controls. There was an increasing trend for plasma levels of Αβ isotypes across AMD progressive stages (p values ranged from 0.052 to 0.0012) (ANCOVA). When adjusted for multiple comparisons analysis, plasma Aβ 1–42 levels, and its ratio with Aβ 1–40 were the most significantly associated with late AMD stages. Consistently with the ANCOVA results for Αβ isotypes, the ROC curve showed a moderate prediction (AUC = - ~ 0.78) of AMD vs control using the Aβ 1−42 isotype.ConclusionPlasma Aβ 1–42 may have utility as a systemic biomarker for AMD.

EFFICACY OF ALIROCUMAB IN 1,191 PATIENTS WITH A WIDE SPECTRUM OF MUTATIONS IN GENES CAUSATIVE FOR FAMILIAL HYPERCHOLESTEROLEMIA

Methods: From 6 clinical trials of alirocumab (one Phase 2, five Phase 3), 1191 patients with elevated LDL-C and phenotypic FH (including 758 treated with alirocumab) were sequenced for mutations using the SEQPRO LIPO platform in LDL receptor (LDLR), apolipoprotein B (APOB), PCSK9 (PCSK9), LDL receptor adaptor protein 1 (LDLRAP1), and signal-transducing adaptor protein 1 (STAP1) genes. New mutations were confirmed by Sanger sequencing and MLPA analysis in case of large gene rearrangements in the original DNA samples.