Tolerability, pharmacokinetics and pharmacodynamics of TA-8995, a selective cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects

Obicetrapib on top of maximally tolerated lipid-modifying therapies in participants with or at high risk for atherosclerotic cardiovascular disease: rationale and designs of BROADWAY and BROOKLYN

BACKGROUND

Obicetrapib, a novel, selective cholesteryl ester transfer protein (CETP) inhibitor, reduces low-density lipoprotein cholesterol (LDL-C), LDL particles, apolipoprotein (Apo) B, and lipoprotein(a) [Lp(a)] and increases high-density lipoprotein cholesterol (HDL-C) when added to statins with or without ezetimibe. By substantially reducing LDL-C, obicetrapib has the potential to lower atherogenic lipoproteins in patients with atherosclerotic cardiovascular disease (ASCVD) or heterozygous familial hypercholesterolemia (HeFH) whose LDL-C levels remain high despite treatment with available maximally tolerated lipid-modifying therapies, addressing an unmet medical need in a patient population at high risk for cardiovascular events.

METHODS AND RESULTS

BROADWAY (NCT05142722) and BROOKLYN (NCT05425745) are ongoing placebo-controlled, double-blind, randomized Phase III trials designed to examine the efficacy, safety, and tolerability of obicetrapib as an adjunct to dietary intervention and maximally tolerated lipid-modifying therapies in participants with a history of ASCVD and/or underlying HeFH whose LDL-C is not adequately controlled. The primary efficacy endpoint was the percent change in LDL-C from baseline to day 84. Other endpoints included changes in Apo B, non-HDL-C, HDL-C, Apo A1, Lp(a), and triglycerides in addition to parameters evaluating safety, tolerability, and pharmacokinetics. BROADWAY also included an adjudicated assessment of major adverse cardiovascular events, measurements of glucose homeostasis, and an ambulatory blood pressure monitoring substudy. A total of 2,532 participants were randomized in BROADWAY and 354 in BROOKLYN to receive obicetrapib 10 mg or placebo (2:1) for 365 days with follow-up through 35 days after the last dose. Results from both trials are anticipated in 2024.

CONCLUSION

These trials will provide safety and efficacy data to support the potential use of obicetrapib among patients with ASCVD or HeFH with elevated LDL-C for whom existing therapies are not sufficiently effective or well-tolerated.

Cholesteryl Ester Transfer Protein Inhibitors and Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Atherosclerosis is a multi-factorial disease, and low-density lipoprotein cholesterol (LDL-C) is a critical risk factor in developing atherosclerotic cardiovascular disease (ASCVD). Cholesteryl-ester transfer-protein (CETP), synthesized by the liver, regulates LDL-C and high-density lipoprotein cholesterol (HDL-C) through the bidirectional transfer of lipids. The novelty of CETP inhibitors (CETPis) has granted new focus towards increasing HDL-C, besides lowering LDL-C strategies. To date, five CETPis that are projected to improve lipid profiles, torcetrapib, dalcetrapib, evacetrapib, anacetrapib, and obicetrapib, have reached late-stage clinical development for ASCVD risk reduction. Early trials failed to reduce atherosclerotic cardiovascular occurrences. Given the advent of some recent large-scale clinical trials (ACCELERATE, HPS3/TIMI55-REVEAL Collaborative Group), conducting a meta-analysis is essential to investigate CETPis' efficacy.

METHODS

We conducted a thorough search of randomized controlled trials (RCTs) that commenced between 2003 and 2023; CETPi versus placebo studies with a ≥6-month follow-up and defined outcomes were eligible.

PRIMARY OUTCOMES

major adverse cardiovascular events (MACEs), cardiovascular disease (CVD)-related mortality, all-cause mortality.

SECONDARY OUTCOMES

stroke, revascularization, hospitalization due to acute coronary syndrome, myocardial infarction (MI).

RESULTS

Nine RCTs revealed that the use of a CETPi significantly reduced CVD-related mortality (RR = 0.89; 95% CI: 0.81-0.98; p = 0.02; I2 = 0%); the same studies also reduced the risk of MI (RR = 0.92; 95% CI: 0.86-0.98; p = 0.01; I2 = 0%), which was primarily attributed to anacetrapib. The use of a CETPi did not reduce the likelihood any other outcomes.

CONCLUSIONS

Our meta-analysis shows, for the first time, that CETPis are associated with reduced CVD-related mortality and MI.

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.

Obicetrapib plus ezetimibe as an adjunct to high-intensity statin therapy: A randomized phase 2 trial

BACKGROUND

Obicetrapib, a selective cholesteryl ester transfer protein (CETP) inhibitor, reduces low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), lipoprotein particles, and apolipoproteins, when added to high-intensity statin in patients with dyslipidemia.

OBJECTIVE

To evaluate the safety and lipid-altering efficacy of obicetrapib plus ezetimibe combination therapy as an adjunct to high-intensity statin therapy.

METHODS

This double-blind, randomized, phase 2 trial administered 10 mg obicetrapib plus 10 mg ezetimibe (n = 40), 10 mg obicetrapib (n = 39), or placebo (n = 40) for 12 weeks to patients with LDL-C >70 mg/dL and triglycerides (TG) <400 mg/dL, on stable high-intensity statin. Endpoints included concentrations of lipids, apolipoproteins, lipoprotein particles, and proprotein convertase subtilisin kexin type 9 (PCSK9), safety, and tolerability.

RESULTS

Ninety-seven patients were included in the primary analysis (mean age 62.6 years, 63.9% male, 84.5% white, average body mass index of 30.9 kg/m2). LDL-C decreased from baseline to week 12 by 63.4%, 43.5%, and 6.35% in combination, monotherapy, and placebo groups, respectively (p<0.0001 vs. placebo). LDL-C levels of <100, <70, and <55 mg/dL were achieved by 100%, 93.5%, and 87.1%, respectively, of patients taking the combination. Both active treatments also significantly reduced concentrations of non-HDL-C, apolipoprotein B, and total and small LDL particles. Obicetrapib was well tolerated and no safety issues were identified.

CONCLUSION

The combination of obicetrapib plus ezetimibe significantly lowered atherogenic lipid and lipoprotein parameters, and was safe and well tolerated when administered on top of high-intensity statin to patients with elevated LDL-C.

Comparison of low-density lipoprotein cholesterol equations in patients with dyslipidaemia receiving cholesterol ester transfer protein inhibition

AIMS

Low-density lipoprotein (LDL-C) lowering is imperative in cardiovascular disease prevention. We aimed to compare accuracy of three clinically-implemented LDL-C equations in a clinical trial of cholesterol ester transfer protein (CETP) inhibition.

METHODS AND RESULTS

Men and women aged 18-75 years with dyslipidaemia were recruited from 17 sites in the Netherlands and Denmark. Patients were randomly assigned to one of nine groups using various combinations of the CETP inhibitor TA-8995 (obicetrapib), statin therapy, and placebo. In pooled measurements over 12 weeks, we calculated LDL-C by the Friedewald, Martin/Hopkins, and Sampson equations, and compared values with preparative ultracentrifugation (PUC) LDL-C overall and with a special interest in the low LDL-C/high triglycerides subgroup. There were 242 patients contributing 921 observations. Overall median LDL-C differences between estimates and PUC were small: Friedewald, 0.00 (25th, 75th: -0.10, 0.08) mmol/L [0 (-4, 3) mg/dL]; Martin/Hopkins, 0.02 (-0.08, 0.10) mmol/L [1 (-3, 4) mg/dL]; and Sampson, 0.05 (-0.03, 0.15) mmol/L [2 (-1, 6) mg/dL]. In the subgroup with estimated LDL-C <1.8 mmol/L (<70 mg/dL) and triglycerides 1.7-4.5 mmol/L (150-399 mg/dL), the Friedewald equation underestimated LDL-C with a median difference versus PUC of -0.25 (-0.33, -0.10) mmol/L [-10 (-13, -4) mg/dL], whereas the median difference by Martin/Hopkins was 0.00 (-0.08, 0.10) mmol/L [0 (-3, 4) mg/dL] and by Sampson was -0.06 (-0.13, 0.00) mmol/L [-2 (-5, 0) mg/dL]. In this subgroup, the proportion of LDL-C observations <1.8 mmol/L (<70 mg/dL) that were correctly classified compared with PUC was 71.4% by Friedewald vs. 100.0% by Martin/Hopkins and 93.1% by Sampson.

CONCLUSION

In European patients with dyslipidaemia receiving a CETP inhibitor, we found improved LDL-C accuracy using contemporary equations vs. the Friedewald equation, and the greatest accuracy was observed with the Martin/Hopkins equation.

REGISTRATION

ClinicalTrials.gov, NCT01970215.

Cholesteryl Ester Transfer Protein Inhibition Reduces Major Adverse Cardiovascular Events by Lowering Apolipoprotein B Levels

Cholesteryl ester transfer protein (CETP) facilitates the exchange of cholesteryl esters and triglycerides (TG) between high-density lipoprotein (HDL) particles and TG-rich, apolipoprotein (apo) B-containing particles. Initially, these compounds were developed to raise plasma HDL cholesterol (HDL-C) levels, a mechanism that was previously thought to lower the risk of atherosclerotic cardiovascular disease (ASCVD). More recently, the focus changed and the use of pharmacologic CETP inhibitors to reduce low-density lipoprotein cholesterol (LDL-C), non-HDL-C and apoB concentrations became supported by several lines of evidence from animal models, observational investigations, randomized controlled trials and Mendelian randomization studies. Furthermore, a cardiovascular outcome trial of anacetrapib demonstrated that CETP inhibition significantly reduced the risk of major coronary events in patients with ASCVD in a manner directly proportional to the substantial reduction in LDL-C and apoB. These data have dramatically shifted the attention on CETP away from raising HDL-C instead to lowering apoB-containing lipoproteins, which is relevant since the newest CETP inhibitor, obicetrapib, reduces LDL-C by up to 51% and apoB by up to 30% when taken in combination with a high-intensity statin. An ongoing cardiovascular outcome trial of obicetrapib in patients with ASCVD is expected to provide further evidence of the ability of CETP inhibitors to reduce major adverse cardiovascular events by lowering apoB. The purpose of the present review is to provide an up-to-date understanding of CETP inhibition and its relationship to ASCVD risk reduction.

Lipid lowering effects of the CETP inhibitor obicetrapib in combination with high-intensity statins: a randomized phase 2 trial

Global guidelines for the management of high-cardiovascular-risk patients include aggressive goals for low-density lipoprotein cholesterol (LDL-C). Statin therapy alone is often insufficient to reach goals and nonstatin options have limitations. Here, we tested the lipid-lowering effects of the cholesteryl ester transfer protein (CETP) inhibitor drug obicetrapib in a randomized, double-blind, placebo-controlled trial in dyslipidaemic patients (n = 120, median LDL-C 88 mg dl^-1) with background high-intensity statin treatment (NCT04753606). Over the course of 8 weeks, treatment with 5 mg or 10 mg obicetrapib resulted in a significant decrease as compared with placebo in median LDL-C concentration (by up to 51%; P < 0.0001), the primary trial outcome. As compared with placebo, obicetrapib treatment also significantly (P < 0.0001) decreased apolipoprotein B (by up to 30%) and non-high-density lipoprotein cholesterol (non-HDL-C) concentration (by up to 44%), and significantly (P < 0.0001) increased HDL-C concentration (by up to 165%; the secondary trial outcomes) and had an acceptable safety profile. These results support the potential of obicetrapib to address an unmet medical need for high-cardiovascular-risk patients.

CETP-inhibitors: from HDL-C to LDL-C lowering agents?

Cholesteryl ester transfer protein (CETP) is a liver-synthesized glycoprotein whose main functions are facilitating transfer of both cholesteryl esters from high-density lipoprotein (HDL) particles to apolipoprotein B (apoB)-containing particles as well as transfer of triglycerides from apoB-containing particles to HDL particles. Novel crystallographic data have shown that CETP exchanges lipids in the circulation by a dual molecular mechanism. Recently, it has been suggested that the atherosclerotic cardiovascular disease (ASCVD) benefit from CETP inhibition is the consequence of the achieved low-density lipoprotein cholesterol (LDL-C) and apoB reduction, rather than through the HDL cholesterol (HDL-C) increase. The use of CETP inhibitors is supported by genetic evidence from Mendelian randomization studies, showing that LDL-C lowering by CETP gene variants achieves equal ASCVD risk reduction as LDL-C lowering through gene proxies for statins, ezetimibe, and proprotein convertase subtilisin–kexin Type 9 inhibitors. Although first-generation CETP inhibitors (torcetrapib, dalcetrapib) were mainly raising HDL-C or had off-target effects, next generation CETP inhibitors (anacetrapib, evacetrapib) were also effective in reducing LDL-C and apoB and have been proven safe. Anacetrapib was the first CETP inhibitor to be proven effective in reducing ASCVD risk. In addition, CETP inhibitors have been shown to lower the risk of new-onset diabetes, improve glucose tolerance, and insulin sensitivity. The newest-generation CETP inhibitor obicetrapib, specifically designed to lower LDL-C and apoB, has achieved significant reductions of LDL-C up to 45%. Obicetrapib, about to enter phase III development, could become the first CETP inhibitor as add-on therapy for patients not reaching their guideline LDL-C targets.

Lipoprotein(a)

Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein with a strong genetic regulation. Up to 90% of the concentrations are explained by a single gene, the LPA gene. The concentrations show a several-hundred-fold interindividual variability ranging from less than 0.1 mg/dL to more than 300 mg/dL. Lp(a) plasma concentrations above 30 mg/dL and even more above 50 mg/dL are associated with an increased risk for cardiovascular disease including myocardial infarction, stroke, aortic valve stenosis, heart failure, peripheral arterial disease, and all-cause mortality. Since concentrations above 50 mg/dL are observed in roughly 20% of the Caucasian population and in an even higher frequency in African-American and Asian-Indian ethnicities, it can be assumed that Lp(a) is one of the most important genetically determined risk factors for cardiovascular disease.Carriers of genetic variants that are associated with high Lp(a) concentrations have a markedly increased risk for cardiovascular events. Studies that used these genetic variants as a genetic instrument to support a causal role for Lp(a) as a cardiovascular risk factor are called Mendelian randomization studies. The principle of this type of studies has been introduced and tested for the first time ever with Lp(a) and its genetic determinants.There are currently no approved pharmacologic therapies that specifically target Lp(a) concentrations. However, some therapies that target primarily LDL cholesterol have also an influence on Lp(a) concentrations. These are mainly PCSK9 inhibitors that lower LDL cholesterol by 60% and Lp(a) by 25-30%. Furthermore, lipoprotein apheresis lowers both, Lp(a) and LDL cholesterol, by about 60-70%. Some sophisticated study designs and statistical analyses provided support that lowering Lp(a) by these therapies also lowers cardiovascular events on top of the effect caused by lowering LDL cholesterol, although this was not the main target of the therapy. Currently, new therapies targeting RNA such as antisense oligonucleotides (ASO) or small interfering RNA (siRNA) against apolipoprotein(a), the main protein of the Lp(a) particle, are under examination and lower Lp(a) concentrations up to 90%. Since these therapies specifically lower Lp(a) concentrations without influencing other lipoproteins, they will serve the last piece of the puzzle whether a decrease of Lp(a) results also in a decrease of cardiovascular events.

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.

Do Cholesteryl Ester Transfer Protein Inhibitors Have a Role in the Treatment of Cardiovascular Disease?

Cholesteryl ester transfer protein (CETP) plays an important role in lipid metabolism and has presented an attractive target for drug development, primarily resting on the hope that CETP inhibition would reduce cardiovascular events through its ability to increase levels of high-density lipoprotein cholesterol (HDL-C). However, clinical development of CETP inhibitors has proven disappointing, with a spectrum of results spanning from evidence of harm, to futility, to only modest benefit in large-scale cardiovascular outcomes trials. A number of additional insights from genomic studies have suggested potential benefits from these agents in specific clinical settings. We review the current state of CETP inhibitors as an approach to targeting cardiovascular risk.

Cholesteryl ester transfer protein and its inhibitors

Most of the cholesterol in plasma is in an esterified form that is generated in potentially cardioprotective HDLs. Cholesteryl ester transfer protein (CETP) mediates bidirectional transfers of cholesteryl esters (CEs) and triglycerides (TGs) between plasma lipoproteins. Because CE originates in HDLs and TG enters the plasma as a component of VLDLs, activity of CETP results in a net mass transfer of CE from HDLs to VLDLs and LDLs, and of TG from VLDLs to LDLs and HDLs. As inhibition of CETP activity increases the concentration of HDL-cholesterol and decreases the concentration of VLDL- and LDL-cholesterol, it has the potential to reduce atherosclerotic CVD. This has led to the development of anti-CETP neutralizing monoclonal antibodies, vaccines, and antisense oligonucleotides. Small molecule inhibitors of CETP have also been developed and four of them have been studied in large scale cardiovascular clinical outcome trials. This review describes the structure of CETP and its mechanism of action. Details of its regulation and nonlipid transporting functions are discussed, and the results of the large scale clinical outcome trials of small molecule CETP inhibitors are summarized.

Design, Synthesis and Biological Evaluation of N,N-Substituted Amine Derivatives as Cholesteryl Ester Transfer Protein Inhibitors

N,N-Substituted amine derivatives were designed by utilizing a bioisosterism strategy. Consequently, twenty-two compounds were synthesized and evaluated for their inhibitory activity against CETP. Structure-activity relationship (SAR) studies indicate that hydrophilic groups at the 2-position of the tetrazole and 3,5-bistrifluoromethyl groups on the benzene ring provide important contributions to the potency. Among these compounds, compound 17 exhibited excellent CETP inhibitory activity (IC₅₀ = 0.38 ± 0.08 μM) in vitro. Furthermore, compound 17 was selected for an in vitro metabolic stability study.

The Changing Face of HDL and the Best Way to Measure It

BACKGROUND

HDL cholesterol (HDL-C) is a commonly used lipid biomarker for assessing cardiovascular health. While a central focus has been placed on the role of HDL in the reverse cholesterol transport (RCT) process, our appreciation for the other cardioprotective properties of HDL continues to expand with further investigation into the structure and function of HDL and its specific subfractions. The development of novel assays is empowering the research community to assess different aspects of HDL function, which at some point may evolve into new diagnostic tests.

CONTENT

This review discusses our current understanding of the formation and maturation of HDL particles via RCT, as well as the newly recognized roles of HDL outside RCT. The antioxidative, antiinflammatory, antiapoptotic, antithrombotic, antiinfective, and vasoprotective effects of HDL are all discussed, as are the related methodologies for assessing these different aspects of HDL function. We elaborate on the importance of protein and lipid composition of HDL in health and disease and highlight potential new diagnostic assays based on these parameters.

SUMMARY

Although multiple epidemiologic studies have confirmed that HDL-C is a strong negative risk marker for cardiovascular disease, several clinical and experimental studies have yielded inconsistent results on the direct role of HDL-C as an antiatherogenic factor. As of yet, our increased understanding of HDL biology has not been translated into successful new therapies, but will undoubtedly depend on the development of alternative ways for measuring HDL besides its cholesterol content.

Re-evaluation of cholesteryl ester transfer protein function in atherosclerosis based upon genetics and pharmacological manipulation

PURPOSE OF REVIEW

To re-evaluate the functions of plasma cholesteryl ester transfer protein (CETP) in atherosclerosis based upon recent findings from human genetics and pharmacological CETP manipulation.

RECENT FINDINGS

CETP is involved in the transfer of cholesteryl ester from HDL to apolipoprotein B-containing lipoproteins, a key step of reverse cholesterol transport (RCT). CETP inhibitors have been developed to raise serum HDL-cholesterol (HDL-C) levels and reduce cardiovascular events. However, outcome studies of three CETP inhibitors (torcetrapib, dalcetrapib and evacetrapib) were prematurely terminated because of increased mortality or futility despite marked increases in HDL-cholesterol and decreases in LDL-cholesterol except for dalcetrapib. Patients with CETP deficiency show remarkable changes in HDL and LDL and are sometimes accompanied by atherosclerotic cardiovascular diseases. Recent prospective epidemiological studies demonstrated atheroprotective roles of CETP. CETP inhibition induces formation of small dense LDL and possibly dysfunctional HDL and downregulates hepatic scavenger receptor class B type I (SR-BI). Therefore, CETP inhibitors may interrupt LDL receptor and SR-BI-mediated cholesterol delivery back to the liver.

SUMMARY

For future drug development, the opposite strategy, namely enhancers of RCT via CETP and SR-BI activation as well as the inducers of apolipoprotein A-I or HDL production might be a better approach rather than delaying HDL metabolism by inhibiting a main stream of RCT in vivo.

Discovery of novel N,N-3-phenyl-3-benzylaminopropionanilides as potent inhibitors of cholesteryl ester transfer protein in vivo

Epidemiological studies have identified that the risk of cardiovascular events increases due to the decreased levels of high density lipoprotein-cholesterol and the elevated levels of low density lipoprotein-cholesterol. Herein, we report a novel series of N,N-3-phenyl-3-benzylaminopropionanilide derivatives, which were identified as potent cholesteryl ester transfer protein (CETP) inhibitor. The initial lead compound L10 (IC50 8.06 μM) was found by pharmacophore-based virtual screening (Dong-Mei Zhao et al., Chin. Chem. Lett.2014, 25, 299). After systematic structure variation and biological testing against CETP, two different series were identified as scaffolds for potent CETP inhibitors. One is N,N-3-phenyl-3-benzylaminopropanamide derivatives, which were investigated in our previous paper (Bioorg. Med. Chem.2015, doi: http://dx.doi.org/10.1016/j.bmc.2015.12.010). The most potent compound HL16 in that series has the IC50 of 0.69 μM. The other series is N,N-3-phenyl-3-benzylaminopropionanilide derivatives, which was investigated in current study. Further optimization of the structure-activity relationship (SAR) resulted in H16 (IC50 0.15 μM), which was discovered as a potent CETP inhibitor in vitro by BODIPY-CE fluorescence assay. In addition, the results of pharmacodynamics studies showed that H16 exhibited both favorable HDL-C enhancement and LDL-C reduction in vivo by hamster. It also has an excellent stability in rat liver microsomal.

A Multidose Study to Examine the Effect of Food on Evacetrapib Exposure at Steady State

PURPOSE

To determine the effect of a high-fat meal on evacetrapib exposure at steady state in healthy participants.

METHODS

This was a randomized, 2-period, 2-sequence, open-label, crossover study. Patients were randomly assigned to 1 of the 2 treatment sequences in which they received evacetrapib 130 mg/d for 10 days following a 10-hour fast each day or following a high-fat breakfast each day. Plasma samples collected through 24 hours were analyzed for evacetrapib concentrations and pharmacokinetic parameter estimates including area under the concentration-time curve during a dosing interval (AUCτ), maximum observed concentration (Cmax), and time of Cmax (tmax) were calculated. Pharmacodynamic parameters, including cholesteryl ester transfer protein (CETP) activity, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides, were also assessed.

RESULTS

A total of 34 males and 6 females, mean age 41.5 years and mean body mass index 26.6 kg/m(2), were enrolled. Statistical analysis showed AUCτ was 44% higher (90% confidence interval [CI]: 29%-62%) and Cmax was 51% higher (90% CI: 28%-79%) in the fed state than in the fasted state, indicating an effect of food. Consistent with higher evacetrapib exposure, changes in HDL-C, LDL-C, and CETP activity appeared to be greater in the fed state than in the fasted state. There were no notable changes in total cholesterol or triglycerides following administration in the fed and fasted states. The 130-mg doses of evacetrapib were well tolerated with and without food.

CONCLUSION

A high-fat meal increased evacetrapib mean exposure at steady state by 44% in healthy participants.

Cholesterol ester transfer protein inhibition by TA-8995 in patients with mild dyslipidaemia (TULIP): a randomised, double-blind, placebo-controlled phase 2 trial

BACKGROUND

Dyslipidaemia remains a significant risk factor for cardiovascular disease and additional lipid-modifying treatments are warranted to further decrease the cardiovascular disease burden. We assessed the safety, tolerability and efficacy of a novel cholesterol esterase transfer protein (CETP) inhibitor TA-8995 in patients with mild dyslipidaemia.

METHODS

In this randomised, double-blind, placebo-controlled, parallel-group phase 2 trial, we recruited patients (aged 18-75 years) from 17 sites (hospitals and independent clinical research organisations) in the Netherlands and Denmark with fasting LDL cholesterol levels between 2·5 mmol/L and 4·5 mmol/L, HDL cholesterol levels between 0·8 and 1·8 mmol/L and triglyceride levels below 4·5 mmol/L after washout of lipid-lowering treatments. Patients were randomly allocated (1:1) by a computer-generated randomisation schedule to receive one of the following nine treatments: a once a day dose of 1 mg, 2·5 mg, 5 mg, or 10 mg TA-8995 or matching placebo; 10 mg TA-8995 plus 20 mg atorvastatin; 10 mg TA-8995 plus 10 mg rosuvastatin or 20 mg atorvastatin or 10 mg rosuvastatin alone. We overencapsulated statins to achieve masking. The primary outcome was percentage change in LDL cholesterol and HDL cholesterol from baseline at week 12, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01970215.

FINDINGS

Between Aug 15, 2013, and Jan 10, 2014, 364 patients were enrolled. At week 12, LDL cholesterol levels were reduced by 27·4% in patients assigned to the 1 mg dose, 32·7% in patients given the 2·5 mg dose, 45·3% in those given the 5 mg dose, and 45·3% in those given the 10 mg dose (p<0·0001). LDL cholesterol levels were reduced by 68·2% in patients given 10 mg TA-8995 plus atorvastatin, and by 63·3% in patients given rosuvastatin plus 10 mg TA-8995 (p<0·0001). A daily dose of 1 mg TA-8995 increased HDL cholesterol levels by 75·8%, 2·5 mg by 124·3%, 5 mg by 157·1%, and 10 mg dose by 179·0% (p<0·0001). In patients receiving 10 mg TA-8995 and 20 mg atorvastatin HDL cholesterol levels increased by 152·1% and in patients receiving 10 mg TA-8995 and 10 mg rosuvastatin by 157·5%. We recorded no serious adverse events or signs of liver or muscle toxic effects.

INTERPRETATION

TA-8995, a novel CETP inhibitor, is well tolerated and has beneficial effects on lipids and apolipoproteins in patients with mild dyslipidaemia. A cardiovascular disease outcome trial is needed to translate these effects into a reduction of cardiovascular disease events.

FUNDING

Dezima.

Advances in the Study of the Antiatherogenic Function and Novel Therapies for HDL

The hypothesis that raising high-density lipoprotein cholesterol (HDL-C) levels could improve the risk for cardiovascular disease (CVD) is facing challenges. There is multitudinous clear clinical evidence that the latest failures of HDL-C-raising drugs show no clear association with risks for CVD. At the genetic level, recent research indicates that steady-state HDL-C concentrations may provide limited information regarding the potential antiatherogenic functions of HDL. It is evident that the newer strategies may replace therapeutic approaches to simply raise plasma HDL-C levels. There is an urgent need to identify an efficient biomarker that accurately predicts the increased risk of atherosclerosis (AS) in patients and that may be used for exploring newer therapeutic targets. Studies from recent decades show that the composition, structure and function of circulating HDL are closely associated with high cardiovascular risk. A vast amount of data demonstrates that the most important mechanism through which HDL antagonizes AS involves the reverse cholesterol transport (RCT) process. Clinical trials of drugs that specifically target HDL have so far proven disappointing, so it is necessary to carry out review on the HDL therapeutics.

High-density lipoprotein-based drug discovery for treatment of atherosclerosis

INTRODUCTION

Although there has been great progress achieved by the use of intensive statin therapy, the burden of atherosclerotic cardiovascular disease (CVD) remains high. This has initiated the search for novel high-density lipoprotein (HDL)-based therapeutics. Recent years have witnessed a shift from traditional raising HDL-C levels to enhancing HDL functionality, in which the process of reverse cholesterol transport (RCT) has acquired much attention.

AREAS COVERED

In this review, the authors describe the key factors involved in RCT process for potential drug targets to reduce the CVD risk. Furthermore, the review provides a summary of the effective screening methods that have been developed to target RCT and their applications. This review also introduces some new strategies currently being clinically developed, which have the potential to improve HDL function in the RCT process.

EXPERT OPINION

It is rational that the functionality of HDL is more important than the plasma HDL-C level in the evaluation of pharmacological treatment in atherosclerosis. HDL-based strategies designed to promote macrophage RCT are a major area of current drug discovery and development for atherosclerotic diseases. A better understanding of the functionality of HDL and its relationship with atherosclerosis will expand our knowledge of the role of HDL in lipid metabolism, holding promise for a future successful HDL-based therapy.

HDL re-examined

PURPOSE OF REVIEW

To summarize the current evidence concerning the role of HDL-C and HDL-associated parameters in the risk for cardiovascular disease (CVD).

RECENT FINDINGS

Numerous population studies have shown that plasma levels of HDL-C are inversely associated with CVD risk; in patient care HDL-C levels are therefore widely implemented in risk estimation models. A number of antiatherogenic properties have been ascribed to the HDL particle, but the hypothesis that HDL is causally related to CVD has been seriously challenged by recent data obtained from both human genetic studies and clinical trials. The final word on HDL-C as a therapeutic target is pending, as a number of clinical endpoint trials specifically focusing on the effect(s) of HDL-C increasing agents are underway. Moreover, recent data show that HDL efflux capacity could hold independent predictive value for CVD events, which clearly highlights the potential need to focus on HDL functionality, rather than on HDL-C levels.

SUMMARY

The dogmatic concept that HDL-C levels predict future CVD events is undisputed, but the role of HDL-C as a causal factor in atherosclerosis has been challenged by a number of different types of studies. In recent years, a paradigm shift toward 'HDL functionality' is apparent. Whether or not optimizing these markers of HDL functionality actually does reduce CVD risk requires formal testing in prospective controlled studies.

HDL and cardiovascular disease

The cholesterol contained within HDL is inversely associated with risk of coronary heart disease and is a key component of predicting cardiovascular risk. However, despite its properties consistent with atheroprotection, the causal relation between HDL and atherosclerosis is uncertain. Human genetics and failed clinical trials have created scepticism about the HDL hypothesis. Nevertheless, drugs that raise HDL-C concentrations, cholesteryl ester transfer protein inhibitors, are in late-stage clinical development, and other approaches that promote HDL function, including reverse cholesterol transport, are in early-stage clinical development. The final chapters regarding the effect of HDL-targeted therapeutic interventions on coronary heart disease events remain to be written.

Novel concepts in HDL pharmacology

High-density lipoproteins (HDL) are a target for drug development because of their proposed anti-atherogenic properties. In this review, we will briefly discuss the currently established drugs for increasing HDL-C, namely niacin and fibrates, and some of their limitations. Next, we will focus on novel alternative therapies that are currently being developed for raising HDL-C, such as CETP inhibitors. Finally, we will conclude with a review of novel drugs that are being developed for modulating the function of HDL based on HDL mimetics. Gaps in our knowledge and the challenges that will have to be overcome for these new HDL based therapies will also be discussed.