No abstract

IMPORTANCE Additional treatment options are needed for patients who do not achieve sufficient reduction in low-density lipoprotein cholesterol (LDL-C) level with available lipid-lowering therapies. OBJECTIVE To assess the efficacy of bempedoic acid vs placebo in patients at high cardiovascular risk receiving maximally tolerated lipid-lowering therapy. DESIGN, SETTING, AND PARTICIPANTS Phase 3, randomized, double-blind, placebo-controlled clinical trial conducted at 91 clinical sites in North America and Europe from November 2016 to September 2018, with a final date of follow-up of September 22, 2018. A total of 779 patients with atherosclerotic cardiovascular disease, heterozygous familial hypercholesterolemia, or both met randomization criteria, which included LDL-C level 70 mg/dL (1.8 mmol/L) or greater while receiving maximally tolerated lipid-lowering therapy. INTERVENTIONS Patients were randomized 2:1 to treatment with bempedoic acid (180 mg) (n = 522) or placebo (n = 257) once daily for 52 weeks. MAIN OUTCOMES AND MEASURES The primary end point was percent change from baseline in LDL-C level at week 12. Secondary measures included changes in levels of lipids, lipoproteins, and biomarkers. RESULTS Among 779 randomized patients (mean age, 64.3 years; 283 women [36.3%]), 740 (95.0%) completed the trial. At baseline, mean LDL-C level was 120.4 (SD, 37.9) mg/dL. Bempedoic acid lowered LDL-C levels significantly more than placebo at week 12 (-15.1% vs 2.4%, respectively; difference,-17.4% [95% CI,-21.0% to-13.9%]; P < .001). Significant reductions with bempedoic acid vs placebo were observed at week 12 for non-high-density lipoprotein cholesterol (-10.8% vs 2.

Despite widespread use of statins to reduce low-density lipoprotein cholesterol (LDL-C) and associated atherosclerotic cardiovascular risk, many patients do not achieve sufficient LDL-C lowering due to muscle-related side effects, indicating novel treatment strategies are required. Bempedoic acid (ETC-1002) is a small molecule intended to lower LDL-C in hypercholesterolemic patients, and has been previously shown to modulate both ATP-citrate lyase (ACL) and AMP-activated protein kinase (AMPK) activity in rodents. However, its mechanism for LDL-C lowering, efficacy in models of atherosclerosis and relevance in humans are unknown. Here we show that ETC-1002 is a prodrug that requires activation by very long-chain acyl-CoA synthetase-1 (ACSVL1) to modulate both targets, and that inhibition of ACL leads to LDL receptor upregulation, decreased LDL-C and attenuation of atherosclerosis, independently of AMPK. Furthermore, we demonstrate that the absence of ACSVL1 in skeletal muscle provides a mechanistic basis for ETC-1002 to potentially avoid the myotoxicity associated with statin therapy.

The structurally diverse peroxisome proliferators ciprofibrate, clofibrate, and bis(2-ethylhexyl) phthalate [(EtHX)2>Pht] increase the activities of hepatic catalase and peroxisomal fatty acid 3-oxidation enzymes in conjunction with profound proliferation of peroxisomes in hepatocytes. In order to delineate the level at which these enzymes are induced in the liver, the transcriptional activity of specific genes for fatty acyl-CoA oxidase (FAOxase) and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme (PBE), the first two enzymes of the peroxisomal f-oxidation system, and for catalase were measured in isolated hepatocyte nuclei obtained from male rats following a single intragastric dose of ciprofibrate, clofibrate, or (EtHx)2>Pht. All three peroxisome proliferators rapidly increased the rate of FAOxase and PBE gene transcription in liver, with near maximal rates (9-15 times control) reached by 1 hr and persisting until at least 16 hr after administration of the compound. FAOxase and PBE mRNA levels, measured by blot-hybridization analysis and FAOxase and PBE protein content, analyzed by immunoblotting, increased concurrently up to at least 16 hr following a single dose of peroxisome proliferator. The catalase mRNA level increased about 1.4-fold, but the transcription rate of the catalase gene was not sign tiy affected. The results show that the peroxisome proliferators clofibrate, ciprofibrate, and (EtHx)2>Pht selectively increase the rate of transcription of peroxisomal fatty add P-oxidation enzyme genes. Whether the tnscriptional effects are mediated by peroxisome proliferatorreceptor complexes remains to be elucidated.

The reticuloendothelial system includes macrophages and endothelial cells. These cells are produced and destroyed in vivo with a precision that implies the existence of homeostatic mechanisms. The stimuli for endothelial cell proliferation and monocyte production are becoming well characterized. However, the mechanisms involved in eliminating these cells are poorly understood. One mechanism involved in cellular elimination is apoptosis, which can be triggered in some cells by ligation of the Fas molecule. In this report we have investigated whether macrophages and endothelial cells express the Fas molecule, and whether Fas transmits an apoptosis-inducing signal in these cells. We demonstrate that macrophages express Fas and readily undergo apoptosis when cultured with anti-Fas. In contrast, while endothelial cells can express the Fas molecule, Fas ligation is insufficient to induce apoptosis. These results suggest differential regulation of Fas function among cells of the reticuloendothelial system, and imply different mechanisms of homeostasis.

Chemical carcinogens can be classified into two categories (i.e. mutagenic and non-mutagenic) on the basis of positive or negative evidence of DNA In 1971, the International Agency for Research on Cancer (IARC), initiated a program for the evaluation of the carcinogenic risk of chemicals to humans based on the epidemiological evidence and evidence of carcinogenicity studies in animals (1). Recently, the IARC attempted to evaluate data from numerous short term tests for additional evidence of carcinogenicity (1). The foregoing is based on the observation that more than 80% of the carcinogens tested were mutagenic in the Salmonella/microsome assay (2-4). The end-points interpreted as positive in the short-term test systems are based on the hypothesis that damage to DNA is possibly a central event in the initiation of carcinogenesis and the neoplastic transformation of mammalian cells (2, [5][6][7][8][9][10][11][12] Carcinogens With and Without Mutagenic ActivityA positive correlation between positivity in short-term mutagenic assays and carcinogenicity has been established (2-5, 13) for a variety of chemicals, which are both carcinogens and mutagens. However, certain chemicals, which are carcinogenic in traditional animal bioassay studies, do not appear to yield positive results in the presently available short-term tests (3, 5, 6, 13-15). Accordingly, carcinogens can be classified into t w o broad types: mutagenic, when there is sufficient evidence for such activity in short term assays, and non-mutagenic, when there is no evidence for activity in mutagenesis assays. The IARC Working Group considered a minimum of three positive results obtained in two of three test systems measuring DNA damage, mutagenicity or chromosomal effects (1) as sufficient evidence for mutagenic activity in short-term tests. Although the IARC Group did not define the criteria for "negative" evidence, we feel that at least three negative results in three test systems measuring DNA damage, mutagenicity or chromosomal aberrations are necessary be-

No abstract

No abstract