Chemical Synthesis, Biological Evaluation, and Cheminformatics Analysis of a Group of Chlorinated Diaryl Sulfonamides: Promising Inhibitors of Cholesteryl Ester Transfer Protein.

BACKGROUND: Hyperlipidemia is characterized by an abnormally elevated serum cholesterol, triglycerides, or both. The relationship between an elevated level of LDL and cardiovascular diseases is well-established. Cholesteryl ester transfer protein (CETP) is an enzyme that moves cholesterol esters and triglycerides between LDL, VLDL, and HDL. CETP inhibition leads to a reduction in cardiovascular disease by raising HDL and minimizing LDL. OBJECTIVE: This study synthesized ten meta-chlorinated benzene sulfonamides 6a-6j and explored their structure-activity relationship. METHODS: The synthesized molecules were characterized using 1H-NMR, 13C-NMR, IR, and HR-MS. Moreover, cheminformatics analyses included pharmacophore mapping, LibDock studies, and cheminformatics characterization using 2-dimensional (2D) molecular descriptors and principal component analysis. RESULTS: Based on in vitro functional CETP assays, compounds 6e, 6i, and 6j demonstrated the strongest inhibitory activities against CETP, reaching 100% inhibition. The inhibitory activity of compounds 6a-6d and 6f-6h ranged from 47.5% to 96.5% at 10 µM concentration. Pharmacophore mapping results suggested CETP inhibitory action, while the docking scores and calculated binding energies predicted favoring binding at the CETP active site. Best-scoring docking poses predicted critical hydrophobic features corresponding to key interactions with His232 and Cys13. Cheminformatics analysis using 2D molecular descriptors indicated that the synthesized compounds span various physicochemical properties and drug-likeness. CONCLUSION: It was found that a chloro moiety at the ortho-position, or a nitro group at the meta and para-positions, improves the CETP inhibitory activity of synthesized analogs. Computational studies suggest the formation of stable ligand-protein complexes between compounds 6a- 6j and CETP.

Obicetrapib: Reversing the Tide of CETP Inhibitor Disappointments.

PURPOSE OF REVIEW: To discuss the history of cardiovascular outcomes trials of cholesteryl ester transfer protein (CETP) inhibitors and to describe obicetrapib, a next-generation, oral, once-daily, low-dose CETP inhibitor in late-stage development for dyslipidemia and atherosclerotic cardiovascular disease (ASCVD). RECENT FINDINGS: Phase 1 and 2 trials have evaluated the safety and lipid/lipoprotein effects of obicetrapib as monotherapy, in conjunction with statins, on top of high-intensity statins (HIS), and with ezetimibe on top of HIS. In ROSE2, 10 mg obicetrapib monotherapy and combined with 10 mg ezetimibe, each on top of HIS, significantly reduced low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B, total LDL particles, small LDL particles, small, dense LDL-C, and lipoprotein (a), and increased HDL-C. Phase 3 pivotal registration trials including a cardiovascular outcomes trial are underway. Obicetrapib has an excellent safety and tolerability profile and robustly lowers atherogenic lipoproteins and raises HDL-C. As such, obicetrapib may be a promising agent for the treatment of ASCVD.

CETP inhibitor evacetrapib enters mouse brain tissue.

High levels of plasma cholesterol, especially high levels of low-density lipoprotein cholesterol (LDL-C), have been associated with an increased risk of Alzheimer's disease. The cholesteryl ester transfer protein (CETP) in plasma distributes cholesteryl esters between lipoproteins and increases LDL-C in plasma. Epidemiologically, decreased CETP activity has been associated with sustained cognitive performance during aging, longevity, and a lower risk of Alzheimer's disease. Thus, pharmacological CETP inhibitors could be repurposed for the treatment of Alzheimer's disease as they are safe and effective at lowering CETP activity and LDL-C. Although CETP is mostly expressed by the liver and secreted into the bloodstream, it is also expressed by astrocytes in the brain. Therefore, it is important to determine whether CETP inhibitors can enter the brain. Here, we describe the pharmacokinetic parameters of the CETP inhibitor evacetrapib in the plasma, liver, and brain tissues of CETP transgenic mice. We show that evacetrapib crosses the blood-brain barrier and is detectable in brain tissue 0.5 h after a 40 mg/kg i.v. injection in a non-linear function. We conclude that evacetrapib may prove to be a good candidate to treat CETP-mediated cholesterol dysregulation in Alzheimer's disease.

Dissecting the Structural Dynamics of Authentic Cholesteryl Ester Transfer Protein for the Discovery of Potential Lead Compounds: A Theoretical Study.

Current structural and functional investigations of cholesteryl ester transfer protein (CETP) inhibitor design are nearly entirely based on a fully active mutation (CETPMutant) constructed for protein crystallization, limiting the study of the dynamic structural features of authentic CETP involved in lipid transport under physiological conditions. In this study, we conducted comprehensive molecular dynamics (MD) simulations of both authentic CETP (CETPAuthentic) and CETPMutant. Considering the structural differences between the N- and C-terminal domains of CETPAuthentic and CETPMutant, and their crucial roles in lipid transfer, we identified the two domains as binding pockets of the ligands for virtual screening to discover potential lead compounds targeting CETP. Our results revealed that CETPAuthentic displays greater flexibility and pronounced curvature compared to CETPMutant. Employing virtual screening and MD simulation strategies, we found that ZINC000006242926 has a higher binding affinity for the N- and C-termini, leading to reduced N- and C-opening sizes, disruption of the continuous tunnel, and increased curvature of CETP. In conclusion, CETPAuthentic facilitates the formation of a continuous tunnel in the "neck" region, while CETPMutant does not exhibit such characteristics. The ligand ZINC000006242926 screened for binding to the N- and C-termini induces structural changes in the CETP unfavorable to lipid transport. This study sheds new light on the relationship between the structural and functional mechanisms of CETP. Furthermore, it provides novel ideas for the precise regulation of CETP functions.

Structure-based mechanism and inhibition of cholesteryl ester transfer protein.

PURPOSE OF REVIEW: Cholesteryl ester transfer proteins (CETP) regulate plasma cholesterol levels by transferring cholesteryl esters (CEs) among lipoproteins. Lipoprotein cholesterol levels correlate with the risk factors for atherosclerotic cardiovascular disease (ASCVD). This article reviews recent research on CETP structure, lipid transfer mechanism, and its inhibition. RECENT FINDINGS: Genetic deficiency in CETP is associated with a low plasma level of low-density lipoprotein cholesterol (LDL-C) and a profoundly elevated plasma level of high-density lipoprotein cholesterol (HDL-C), which correlates with a lower risk of atherosclerotic cardiovascular disease (ASCVD). However, a very high concentration of HDL-C also correlates with increased ASCVD mortality. Considering that the elevated CETP activity is a major determinant of the atherogenic dyslipidemia, i.e., pro-atherogenic reductions in HDL and LDL particle size, inhibition of CETP emerged as a promising pharmacological target during the past two decades. CETP inhibitors, including torcetrapib, dalcetrapib, evacetrapib, anacetrapib and obicetrapib, were designed and evaluated in phase III clinical trials for the treatment of ASCVD or dyslipidemia. Although these inhibitors increase in plasma HDL-C levels and/or reduce LDL-C levels, the poor efficacy against ASCVD ended interest in CETP as an anti-ASCVD target. Nevertheless, interest in CETP and the molecular mechanism by which it inhibits CE transfer among lipoproteins persisted. Insights into the structural-based CETP-lipoprotein interactions can unravel CETP inhibition machinery, which can hopefully guide the design of more effective CETP inhibitors that combat ASCVD. Individual-molecule 3D structures of CETP bound to lipoproteins provide a model for understanding the mechanism by which CETP mediates lipid transfer and which in turn, guide the rational design of new anti-ASCVD therapeutics.

Serum Cholesteryl Ester Transfer Protein (CETP) and Sortilin (SORT) in Patients with Psoriasis with Relation to Systemic Treatment.

Psoriasis is a common inflammatory skin disease, which is tightly associated with metabolic disorders. Cholesteryl ester transfer protein (CETP) and sortilin (SORT) are molecules engaged in lipid metabolism of proatherogenic properties. They have been hardly ever studied in psoriasis before. Serum CETP and SORT concentrations were measured in 33 patients with plaque-type psoriasis before and after 12 weeks of treatment with methotrexate or acitretin. There was no significant difference in CEPT and SORT serum concentrations between patients and controls. Positive correlations between CETP after the treatment with acitretin and activity of transaminases (R = 0.65, R = 0.56, respectively) were noted. CETP was positively related with triglycerides (R = 0.49), glucose (R = 0.54) and CRP (R = 0.64) before the treatment with methotrexate, which all disappeared afterwards. Systemic therapy with methotrexate caused normalization of SORT concentration. There was significant correlation between SORT and WBC (p < 0.01) and CRP (p < 0.05). CETP and SORT cannot be used as individual biomarkers. Nevertheless, they show some interesting relations with other parameters. Increased concentration of CETP perhaps could investigated as a marker of liver side effects of acitretin treatment in psoriatics. SORT could be considered as a new indicator of metabolically induced inflammation in psoriasis. Methotrexate may be preferred in patients with high SORT concentrations. Further studies are needed to establish their exact role in psoriatic patients.

Disturbances of the transfer of cholesterol to high-density lipoprotein (HDL) in patients with peripheral artery disease with or without type 2 diabetes mellitus.

INTRODUCTION: Low high-density lipoprotein (HDL)-cholesterol is frequent in patients with peripheral artery disease (PAD) and also in type 2 diabetes mellitus (T2DM), the major risk factor for PAD. The transfer of cholesterol from the other lipoproteins to HDL is an important aspect of HDL metabolism and function, and may contribute to atherogenic mechanisms that lead to PAD development. OBJECTIVE: The aim of this study was to investigate the status of cholesterol transfers in patients with PAD without or with T2DM. METHODS: Patients with PAD (n = 19), with PAD and T2DM (PAD + DM, n = 19), and healthy controls (n = 20), all paired for age, sex, and BMI were studied. Transfer of both forms of cholesterol, unesterified (UC) and esterified (EC), was performed by incubating plasma with a donor nanoemulsion containing radioactive UC and EC, followed by chemical precipitation and HDL radioactive counting. RESULTS: Low-density lipoprotein (LDL)-cholesterol and triglycerides were similar in the three groups. Compared to controls, HDL-C was lower in PAD + DM (p < 0.05), but not in PAD. Transfer of UC was lower in PAD + DM than in PAD and controls (4.18 ± 1.17%, 5.13 ± 1.44%, 6.59 ± 1.25%, respectively, p < 0.001). EC transfer tended to be lower in PAD + DM than in controls (2.96 ± 0.60 vs 4.12 ± 0.89%, p = 0.05). Concentrations of cholesteryl ester transfer protein (CETP) and lecithin-cholesterol acyltransferase (LCAT), both involved in HDL metabolism, were not different among the three groups. CONCLUSION: Deficient cholesterol transfer to HDL may play a role in PAD pathogenesis. Since UC transfer to HDL was lower in PAD + DM compared to PAD alone, it is possible that defective HDL metabolism may contribute to the higher PAD incidence in patients with T2DM.Keywords.

Low-density lipoprotein receptor is required for cholesteryl ester transfer protein to regulate triglyceride metabolism in both male and female mice.

Elevated triglycerides (TGs) and impaired TG clearance increase the risk of cardiovascular disease in both men and women, but molecular mechanisms remain poorly understood. Cholesteryl ester transfer protein (CETP) is a lipid shuttling protein known for its effects on high-density lipoprotein cholesterol. Although mice lack CETP, transgenic expression of CETP in mice alters TG metabolism in males and females by sex-specific mechanisms. A unifying mechanism explaining how CETP alters TG metabolism in both males and females remains unknown. Since low-density lipoprotein receptor (LDLR) regulates both TG clearance and very low density lipoprotein (VLDL) production, LDLR may be involved in CETP-mediated alterations in TG metabolism in both males and females. We hypothesize that LDLR is required for CETP to alter TG metabolism in both males and females. We used LDLR null mice with and without CETP to demonstrate that LDLR is required for CETP to raise plasma TGs and to impair TG clearance in males. We also demonstrate that LDLR is required for CETP to increase TG production and to increase the expression and activity of VLDL synthesis targets in response to estrogen. Additionally, we show that LDLR is required for CETP to enhance ß-oxidation. These studies support that LDLR is required for CETP to regulate TG metabolism in both males and females.

Cholesteryl Ester Transfer Protein Impairs Triglyceride Clearance via Androgen Receptor in Male Mice.

Elevated postprandial triacylglycerols (TAG) are an important risk factor for cardiovascular disease. Men have higher plasma TAG and impaired TAG clearance compared to women, which may contribute to sex differences in risk of cardiovascular disease. Understanding mechanisms of sex differences in TAG metabolism may yield novel therapeutic targets to prevent cardiovascular disease. Cholesteryl ester transfer protein (CETP) is a lipid shuttling protein known for its effects on high-density lipoprotein (HDL) cholesterol levels. Although mice lack CETP, we previously demonstrated that transgenic CETP expression in female mice alters TAG metabolism. The impact of CETP on TAG metabolism in males, however, is not well understood. Here, we demonstrate that CETP expression increases plasma TAG in males, especially in very-low density lipoprotein (VLDL), by impairing postprandial plasma TAG clearance compared to wild-type (WT) males. Gonadal hormones were required for CETP to impair TAG clearance, suggesting a role for sex hormones for this effect. Testosterone replacement in the setting of gonadectomy was sufficient to restore the effect of CETP on TAG. Lastly, liver androgen receptor (AR) was required for CETP to increase plasma TAG. Thus, expression of CETP in males raises plasma TAG by impairing TAG clearance via testosterone signaling to AR. Further understanding of how CETP and androgen signaling impair TAG clearance may lead to novel approaches to reduce TAG and mitigate risk of cardiovascular disease.

Cholesteryl Ester Transfer Protein and Lipid Metabolism and Cardiovascular Diseases.

In this chapter, we present the major advances in CETP research since the detection, isolation, and characterization of its activity in the plasma of humans and several species. Since CETP is a major modulator of HDL plasma levels, the clinical importance of CETP activity was recognized very early. We describe the participation of CETP in reverse cholesterol transport, conflicting results in animal and human genetic studies, possible new functions of CETP, and the results of the main clinical trials on CETP inhibition. Despite major setbacks in clinical trials, the hypothesis that CETP inhibitors are anti-atherogenic in humans is still being tested.

Effect of Food on the Pharmacokinetics of 2 Formulations of DRL-17822, a Novel Selective Cholesteryl Ester Transfer Protein (CETP) Inhibitor, in Healthy Males.

DRL-17822 is a novel selective cholesteryl ester transfer protein inhibitor that showed an increased exposure, including an increase of >20-fold of maximum concentration and area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, following a high-fat breakfast using a nanocrystal formulation. To reduce this effect of food, we generated an amorphous solid dispersion formulation. In this study, we compared the food effect of both formulations of DRL-17822 in a 2-part randomized, open-label, 4-way crossover study involving healthy adult males 18-45 years of age. In both parts of the study, 12 subjects received both formulations of DRL-17822 in both the fasted and fed states; a low-fat breakfast was provided in the first part and a high-fat breakfast in the second part. Compared to the nanocrystal formulation, the amorphous solid dispersion formulation substantially increased DRL-17822 exposure in the fasted state, including increased maximum concentration, area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, and area under plasma concentration-time curve from time zero to infinity. Following a high-fat breakfast, DRL-17822 exposure was increased to a lesser extent in the amorphous solid dispersion formulation compared to the nanocrystal formulation (P < .001). Moreover, compared to the nanocrystal formulation the amorphous solid dispersion formulation caused a more pronounced increase in high-density lipoprotein in the fasted state. Consuming breakfast increased the effect of DRL-17822 on high-density lipoprotein. Taken together, our results indicate that by improving its formulation, DRL-17822 has a favorable exposure profile and therefore a more predictable food effect profile.

Cholesteryl ester transfer protein (CETP), HDL capacity of receiving cholesterol and status of inflammatory cytokines in patients with severe heart failure.

BACKGROUND: Heart failure (HF) courses with chronic inflammatory process and alterations in lipid metabolism may aggravate the disease. The aim was to test whether the severity of HF, using brain natriuretic peptide (BNP) as a marker, is associated with alterations in functional aspects of HDL, such as lipid transfer, cholesterol ester transfer protein (CETP) and lecithin-cholesterol acyltransferase (LCAT) concentration. METHODS: Twenty-five HF patients in NYHA class I/II and 23 in class III/IV were enrolled. Plasma lipids, apolipoproteins, CETP, LCAT, oxidized-LDL (oxLDL) and paraoxonase-1 (PON-1) activity were determined. Lipid transfer from a donor artificial nanoparticle to HDL was measured by in vitro assay. RESULTS: Total cholesterol (p = 0.049), LDL-C (p = 0.023), non-HDL-C (p = 0.029) and CETP, that promotes lipid transfer among lipoproteins (p = 0.013), were lower in III/IV than in I/II group. Triglycerides, HDL-C, apo A-I, apo B, oxLDL, LCAT, enzyme that catalyzes serum cholesterol esterification, PON-1 activity, and in vitro transfers of cholesterol, triglycerides and phospholipids to HDL, important steps in HDL metabolism, were equal. IL-8 was higher in III/IV (p = 0.025), but TNFα, IL-1ß, IL-6 and MCP-1 were equal. BNP was negatively correlated with CETP (r = - 0.294; p = 0.042) and positively correlated with IL-8 (r = 0.299; p = 0.039). CONCLUSIONS: Our results disclosed the relationship between CETP levels and HF severity, by comparing two HF groups and by correlation analysis. Lower CETP levels may be a marker of HF aggravation and possibly of worse prognosis. Practical applications of this initial finding, as the issue whether CETP could be protective against HF aggravation, should be explored in larger experimental and clinical studies.

Cardiovascular outcomes trial with anacetrapib in subjects with high cardiovascular risk - are major benefits REVEALed?

INTRODUCTION: The actions of the cholesteryl ester transfer protein (CETP) inhibitors (torcetrapib, dalcetrapib and evacetrapib) include increasing high-density lipoprotein (HDL) cholesterol, but they do not reduce cardiovascular outcomes in subjects with high cardiovascular risk. Anacetrapib also inhibits CETP, increases HDL cholesterol and lowers low-density lipoprotein (LDL) cholesterol. Areas covered: This evaluation is of the REVEAL (Randomized Evaluation of the Effects of Anacetrapib through Lipid Modification) trial, which was a cardiovascular outcomes trial with anacetrapib in subjects with high cardiovascular risk. Consideration is given as to whether increasing HDL cholesterol, lowering LDL cholesterol or other mechanisms/factors underlying the positive outcome with this CETP inhibitor. Expert opinion: After three years, the REVEAL trial with anacetrapib, demonstrated cardiovascular benefits, but not a reduction in coronary artery deaths. The reductions were not significant in years one and two. Thus, in my opinion, the benefits of anacetrapib were not major, and may not apply in 'real' world populations where adherence to medicines is lower than in REVEAL. Also, lowering LDL cholesterol and off-target mechanisms of anacetrapib may have contributed to any beneficial and/or toxic effects. Anacetrapib has a good safety profile.

Pharmacokinetics, pharmacodynamics and clinical efficacy of non-statin treatments for hypercholesterolemia.

INTRODUCTION: Hypercholesterolemia is the main modifiable risk factor for atherosclerosis progression and cardiovascular disease (CVD) development. Its pharmacological management is usually based on the prescription of statins, that in some cases are not however fully effective to reach the desired Low-Density-Lipoproteins cholesterol (LDL-C) target, or are not tolerated by patients due to side effects. Areas covered: This manuscript summarizes the basic properties of the emerging new classes of lipid-lowering drugs such as ezetimibe, Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) inhibitors, and Microsomal Triglyceride Transfer Protein (MTP) inhibitors, also citing new drugs in development. Our aim is to describe the main pharmacodynamic and pharmacokinetic characteristics, the available efficacy, tolerability and safety data obtained in randomized clinical trials where these drugs were tested. Expert opinion: Non-statin lipid-lowering drugs can be considered an excellent strategy to reduce the residual CV risk, also represented by non-target LDL-C values and high lipoprotein(a) serum levels. In particular, the approved PCSK9 inhibitors (Evolocumab and Alirocumab) have been very effective in optimizing plasma LDL-C values and reducing CV event risk.

Cord and maternal sera from small neonates share dysfunctional lipoproteins with proatherogenic properties: Evidence for Barker's hypothesis.

BACKGROUND: Fetal growth restriction (GR) is associated with perinatal mortality and subsequent metabolic disorders in adulthood. Until now, there is little information regarding changes in the properties of lipoproteins from growth-restricted fetuses and their maternal sera. OBJECTIVE: To identify unique lipoprotein biomarkers for fetal GR in maternal and cord sera from small neonates, we analyzed lipoprotein compositions and functions. METHODS: Lipoprotein compositions and functions were compared between cord blood and maternal blood among small for gestational age neonates (SGA; n = 15, 2589 ± 50 g) and appropriate for gestational age neonates (AGA; n = 15) in Korea. RESULTS: Cord blood from the SGA group showed 2-fold higher triglyceride (TG) and TG/high-density lipoprotein cholesterol levels than the AGA group as well as significantly lower (up to 20%) paraoxonase activity and apolipoprotein (apo) A-I content. The SGA group showed the highest cholesteryl ester transfer protein activities in both cord and maternal sera. SGA neonates showed elevated apo-B content in very low-density lipoprotein, 52% reduction of apo A-I content in high-density lipoprotein, and 30% increased glycation (P < .001) compared with AGA neonates. Especially, low-density lipoprotein from the SGA group showed 1.9-fold higher sensitivity to oxidation as well as 3-fold greater uptake into macrophages, suggesting stronger proatherosclerotic properties. Lipoproteins from maternal serum of SGA neonates showed greater oxidation along with TG enrichment and loss of antioxidant ability. On microinjection of cord serum (50 nL) into zebrafish embryos, the SGA group showed the most severe embryonic damage. CONCLUSIONS: Lipoproteins from cord and maternal sera of SGA neonates resulted in severe impairment of functional and structural correlations accompanied by greater pro-oxidant and proatherosclerotic properties.

Pharmacogenetics of Lipid-Lowering Agents: an Update Review on Genotype-Dependent Effects of HDL-Targetingand Statin Therapies.

PURPOSE OF REVIEW: High-density lipoproteins (HDL) are involved in reverse cholesterol transport. Results from randomized trials of HDL-targeting therapies, including cholesteryl ester transfer protein (CETP) inhibitors, have shown a lack of benefit in unsegmented populations. These observations could be explained by inter-individual variability of clinical responses to such agents depending on the patients' genotypes. In parallel, although lowering of LDL cholesterol (LDL-c) with statin therapy reduces the risk of vascular events in a wide range of individuals, inter-individual variability exists with regard to LDL-c-lowering response as well as efficacy in reducing major cardiovascular events. RECENT FINDINGS: Pharmacogenomic analyses were performed in the dal-OUTCOMES and dal-PLAQUE-2 studies. Beneficial and concordant results were observed in patients with the favorable genotype when treated with the CETP inhibitor dalcetrapib. Similarly, previous studies revealed genetic variants associated with differential LDL-c response to statin therapy. In this review, we discuss the pharmacogenetic determinants of HDL-targeting and statin therapy responses in light of the latest available published data, and their potential therapeutic applications.

No cardiovascular benefit with evacetrapib - is this the end of the road for the 'cetrapibs'?

INTRODUCTION: Increasing high-density lipoprotein(HDL) cholesterol levels predict improved cardiovascular outcomes. However, inhibiting cholesteryl ester transfer protein (CETP) to increase HDL cholesterol, with the 'cetrapibs' (torcetrapib and dalcetrapib), did not improve cardiovascular clinical outcomes. Despite these findings, the clinical outcomes trial with evacetrapib continued. Areas covered: Treatment with evacetrapib increased the levels of HDL by ~130%, and decreased low-density lipoprotein (LDL) cholesterol by ~37%. However, The Assessment of Clinical Effects of Cholesteryl Ester Transfer Protein Inhibition with Evacetrapib in Patients at a High Risk for Vascular Outcomes (ACCELERATE) trial did not show reduced cardiovascular outcomes with this cetrapib. Evacetrapib may have failed because increasing HDL cholesterol may not be beneficial in the presence of coronary artery disease and/or it is possible that evacetrapib has toxic effects that counter any beneficial effects. Expert opinion: In addition to our understanding of the relationships between CETP, HDL cholesterol and cardiovascular disease being incomplete, recent meta-analysis evidence suggests that increasing HDL cholesterol does not improve cardiovascular outcomes in subjects taking statins, and this may explain the failure of evacetrapib. Also, the preclinical characteristics of the cetrapibs, especially off-target mechanisms, were not explored prior to clinical trial, and may have contributed to the failure of cetrapibs, including evacetrapib.

Fertility and Embryo-Fetal Development Assessment in Rats and Rabbits with Evacetrapib: A Cholesteryl Ester Transfer Protein Inhibitor.

BACKGROUND: The purpose of these studies was to evaluate the effects of evacetrapib on male and female fertility and on embryo-fetal development (EFD). METHODS: Evacetrapib, a potent and selective inhibitor of cholesteryl ester transfer protein (CETP), was administered daily by oral gavage starting 2 weeks (for female) or 4 weeks (for male) before mating, during cohabitation, and until necropsy in the male rat fertility study or through gestation day (GD) 17 in the female rat combined fertility/EFD study. For rabbit EFD studies, animals were dosed from GDs 7 to 19 or from 1 week before mating through GD 19. Dose levels of evacetrapib ranged from 60 to 600 mg/kg for rats and from 1 to 100 mg/kg/day for rabbits. RESULTS: Parental findings in rats included decreased body weight and food consumption and moribund euthanasia in animals given 600 mg/kg/day and decreased food consumption at 300 mg/kg/day. There were no adverse effects on estrus cycling, fertility indices, sperm parameters, maternal reproductive parameters, male reproductive tissue, or fetal viability, growth, or external/visceral morphology. An increase in the incidence of 14th rudimentary ribs, a minor, transient variation considered nonadverse, was the only significant developmental finding in rats given 600 mg/kg/day. Slight decreases in body weight and food consumption at 100 mg/kg/day were the only maternal effects observed in rabbits with no adverse developmental effects noted. CONCLUSION: No adverse effects on fertility or EFD were observed in rats at doses up to 600 mg/kg/day and no adverse effects on EFD were noted in rabbits at doses up to 100 mg/kg/day. Birth Defects Research 109:513-527, 2017. © 2017 Wiley Periodicals, Inc.

Investigational therapies for hypercholesterolemia.

INTRODUCTION: Cardiovascular morbidity and mortality are of increasing concern, not only to patients but also to the health care profession and service providers. The preventative benefit of treatment of dyslipidaemia is unquestioned but there is a large, so far unmet need to improve clinical outcome. There are exciting new discoveries of targets that may translate into improved clinical outcome. Areas covered: This review highlights some new pathways in cholesterol and triglyceride metabolism and examines new targets, new drugs and new molecules. The review includes the results of recent trials of relatively new drugs that have shown benefit in cardiovascular endpoint outcomes, drugs that have been licenced without endpoint trials yet available and new drugs that have not yet been licenced but have produced exciting results in animal studies and some in early phase 2 human studies. Expert opinion: The new areas that have been discovered as the cause of dyslipidaemia have opened up a host of new targets for new drugs including antisense RNA's, microRNA's and human monoclonal antibodies. The plethora of new targets and new drugs has made it an extraordinarily exciting time in the development of therapeutics to combat atherosclerosis.

The association of circulating microRNA-30c with atherogenic lipoprotein subfractions and composition.

Circulating miR-30c has been linked to various aspects of cholesterol homeostasis. The aim of this study was to determine the association of circulating miR-30c with the atherogenic lipoprotein subfractions. Samples from subjects who were given placebo (n=22) in a randomised, double-blind crossover study were used. Subjects were divided into non-atherogenic lipoprotein phenotype (Non-ALP; n=12; triglycerides <2.0mmol/L) and atherogenic lipoprotein phenotype (ALP; n=10; triglycerides ≥2.0mmol/L) groups. All lipid and lipoprotein measurements, RNA extraction and reverse transcription-quantitative real-time polymerase chain reaction were undertaken using standard procedures. Subjects with ALP weighed significantly more than their non-ALP counterparts (p=0.023). In the non-ALP group there was significant correlation between miR-30c and components within VLDL1, namely triglyceride which showed a negative association (p=0.035) whereas phospholipids and cholesterol-ester were both positively correlated (p=0.025 and 0.014, respectively). In contrast, in the ALP group there was a significant correlation between the expression of miR-30c and components within VLDL2, namely triglyceride, which was positively associated (p=0.013). This study reveals specificity with regards to the effect of miR-30c on VLDL subfractions based on the individual's lipoprotein phenotype and implicates roles for microsomal-triglyceride transfer-protein and cholesteryl-ester-transfer-protein in LDL and VLDL metabolism, respectively.