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.)

The DiscovEHR collaboration between the Regeneron Genetics Center and Geisinger Health System couples high-throughput sequencing to an integrated health care system using longitudinal electronic health records (EHRs). We sequenced the exomes of 50,726 adult participants in the DiscovEHR study to identify ~4.2 million rare single-nucleotide variants and insertion/deletion events, of which ~176,000 are predicted to result in a loss of gene function. Linking these data to EHR-derived clinical phenotypes, we find clinical associations supporting therapeutic targets, including genes encoding drug targets for lipid lowering, and identify previously unidentified rare alleles associated with lipid levels and other blood level traits. About 3.5% of individuals harbor deleterious variants in 76 clinically actionable genes. The DiscovEHR data set provides a blueprint for large-scale precision medicine initiatives and genomics-guided therapeutic discovery.

Objective. To assess the efficacy and safety of rilonacept (Interleukin-1 [IL-1] Trap), a long-acting and potent inhibitor of IL-1, in patients with cryopyrinassociated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS).Methods. Forty-seven adult patients with CAPS, as defined by mutations in the causative NLRP3 (CIAS1) gene and pathognomonic symptoms, were enrolled in 2 consecutive phase III studies. Study 1 involved a 6-week randomized double-blind comparison of weekly subcutaneous injections of rilonacept (160 mg) versus placebo. Study 2 consisted of 9 weeks of single-blind treatment with rilonacept (part A), followed by a 9-week, randomized, double-blind, placebo-controlled withdrawal procedure (part B). Primary efficacy was evaluated using a validated composite key symptom score.Results. Forty-four patients completed both studies. In study 1, rilonacept therapy reduced the group mean composite symptom score by 84%, compared with 13% with placebo therapy (primary end point; P < 0.0001 versus placebo). Rilonacept also significantly improved all other efficacy end points in study 1 (numbers of multisymptom and single-symptom disease flare days, single-symptom scores, physician's and patient's global assessments of disease activity, limitations in daily activities, and C-reactive protein and serum amyloid A [SAA] levels). In study 2 part B, rilonacept was superior to placebo for maintaining the improvements seen with rilonacept therapy, as shown by all efficacy parameters (primary end point; P < 0.0001 versus placebo). Rilonacept was generally well tolerated; the most common adverse events were injection site reactions.Conclusion. Treatment with weekly rilonacept provided marked and lasting improvement in the clinical signs and symptoms of CAPS, and normalized the levels of SAA from those associated with risk of developing amyloidosis. Rilonacept exhibited a generally favorable safety and tolerability profile.Cryopyrin-associated periodic syndromes (CAPS) are a group of inherited inflammatory disorClinicalTrials.gov identifier: NCT00288704.

Gain-of-function mutations in a serine protease, proprotein convertase subtilisin/kexin 9 (PCSK9), have been associated with high plasma levels of low-density lipoprotein (LDL) cholesterol and an increased incidence of coronary heart disease. Previous studies showed that PCSK9 loss-of-function mutations in patients were associated with low levels of LDL cholesterol and a reduced incidence of coronary heart disease. This suggested that pharmacologic inhibition of PCSK9 could lower LDL cholesterol levels in patients with hypercholesterolemia. REGN727/SAR236553 (REGN727) is an investigational, fully human monoclonal antibody highly specific for human PCSK9. This antibody blocks the interaction of PCSK9 with LDL receptors.This report presents the results of 3 phase 1 studies of REGN727 in humans. The participants were healthy volunteers and patients with familial or nonfamilial hypercholesterolemia. Three separate clinical studies of REGN727 were conducted. The first two compared the effect of single doses of REGN727, administered either intravenously (n = 40) or subcutaneously (n = 32), in healthy volunteers and a placebo. After these 2 single-dose studies, a randomized, placebocontrolled multiple-dose trial that investigated the effect of REGN727in 3 separate cohorts with hypercholesterolemia was conducted. The first cohort was composed of 21 subjects with heterozygous familial hypercholesterolemia and the second cohort consisted of 30 subjects with nonfamilial hypercholesterolemia. All patients in these 2 cohorts were receiving atorvastatin therapy and had a baseline LDL cholesterol level greater than 100 mg/dL (2.6 mM). The third cohort was composed of 10 subjects with nonfamilial hypercholesterolemia who had a baseline LDL cholesterol level greater than 130 mg/dL (3.4 mM); these patients were treated only with a modified diet.Patients in the multiple-dose study were randomly assigned to receive subcutaneous REGN727 (50, 100, or 150 mg) or placebo administered on days 1, 29, and 43. The primary study outcome was the incidence of adverse events. The major secondary end point evaluated was the effect of REGN727 on the lipid profile.None of the subjects receiving REGN727 withdrew from the study early because of an adverse event. There was a significant reduction in levels of LDL cholesterol among patients receiving REGN727 in all studies. Levels of LDL in the multiple-dose study were as follows: REGN727 doses of 50, 100, and 150 mg reduced LDL levels in the combined atorvastatin-treated populations to 77.5 mg/dL (2.00 mL), 61.3 mg/dL (1.59 mL), and 53.8 mg/dL (1.39 mL), respectively; differences in the change from baseline with the 50-, 100-, and 150-mg doses were j39.2, j53.7, and j61.0 percentage points compared with placebo (P G 0.001 for all 3 comparisons).These phase 1 trials suggest a role for PCSK9 in the regulation of LDL cholesterol in humans.