Evacetrapib and cardiovascular outcomes: reasons for lack of efficacy

Cardioprotective Properties of HDL: Structural and Functional Considerations

BACKGROUND

As Mendelian Randomization (MR) studies showed no effect of variants altering HDL-cholesterol (HDL-C) levels concerning Cardiovascular Disease (CVD) and novel therapeutic interventions aiming to raise HDL-C resulted to futility, the usefulness of HDL-C is unclear.

OBJECTIVE

As the role of HDL-C is currently doubtful, it is suggested that the atheroprotective functions of HDLs can be attributed to the number of HDL particles, and their characteristics including their lipid and protein components. Scientific interest has focused on HDL function and on the causes of rendering HDL particles dysfunctional, whereas the relevance of HDL subclasses with CVD remains controversial.

METHODS

The present review discusses changes in quality as much as in quantity of HDL in pathological conditions and the connection between HDL particle concentration and cardiovascular disease and mortality. Emphasis is given to the recently available data concerning the cholesterol efflux capacity and the parameters that determine HDL functionality, as well as to recent investigations concerning the associations of HDL subclasses with cardiovascular mortality.

RESULTS

MR studies or pharmacological interventions targeting HDL-C are not in favor of the hypothesis of HDL-C levels and the relationship with CVD. The search of biomarkers that relate with HDL functionality is needed. Similarly, HDL particle size and number exhibit controversial data in the context of CVD and further studies are needed.

CONCLUSION

There is no room for the old concept of HDL as a silver bullet,as HDL-C cannot be considered a robust marker and does not reflect the importance of HDL particle size and number. Elucidation of the complex HDL system, as well as the finding of biomarkers, will allow the development of any HDL-targeted therapy.

The effect and safety of anacetrapib in the treatment of dyslipidemia: a systematic review and meta-analysis

BACKGROUND

Cardiovascular disease (CVD) is the major cause of morbidity and mortality worldwide. Anacetrapib may be a new treatment option that has a cardiovascular benefit for the management of dyslipidemia.

OBJECTIVE

The aim of our current study was to perform a systematic review and meta-analysis of all randomized controlled trials (RCTs) assessing the effect and safety of anacetrapib in the treatment of dyslipidemia.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library database from their inception to 5 October 2017, with the terms: 'anacetrapib' and 'placebo'. From 287 initial citations, 10 studies including 34781 patients with dyslipidemia were included in the final systematic review and meta-analysis.

RESULTS

Pooled results showed that anacetrapib significantly increased high density lipoprotein cholesterol (HDL-C) [weighted mean differences (WMD) 53.07, 95% confidence interval (95% CI) 46.79 to 59.36] and apolipoprotein AI (ApoAI) (WMD 53.44, 95% CI 45.72 to 61.16). Our study also showed that anacetrapib significantly reduced low density lipoprotein cholesterol (LDL-C) (WMD -32.99; 95% CI -37.13 to -28.86), Non-HDL-C (WMD -39.19; 95% CI -52.22 to -26.16), triglycerides (TG) (WMD -9.97; 95% CI -10.54 to -9.41), apolipoprotein B (ApoB) (WMD -22.55; 95% CI -28.56 to -16.54) and lipoprotein a [LP(a)] (WMD -13.35; 95% CI -18.31 to -8.39). Our results demonstrated that there was no significant difference in all the following adverse events between the anacetrapib group and placebo group: [hepato-toxicity (OR 0.90, 95% CI: 0.75 to 1.07); musculoskeletal injury (OR 1.01, 95% CI: 0.88 to 1.15); drug-related adverse event (OR 1.00, 95% CI: 0.96 to 1.05); drug-related withdrawn (OR 1.01, 95% CI: 0.95 to 1.08)].

CONCLUSIONS

Although further studies are needed, our findings clearly offer support to the use of anacetrapib in the clinical management of patients with dyslipidemia.

Anacetrapib, a New CETP Inhibitor: The New Tool for the Management of Dyslipidemias?

Cholesteryl ester transfer protein (CETP) inhibitors significantly increase serum high-density lipoprotein cholesterol (HDL) cholesterol levels and decrease low-density lipoprotein cholesterol (LDL) cholesterol concentration. However, three drugs of this class failed to show a decrease of cardiovascular events in high-risk patients. A new CETP inhibitor, anacetrapib, substantially increases HDL cholesterol and apolipoprotein (Apo) AI levels with a profound increase of large HDL2 particles, but also pre-β HDL particles, decreases LDL cholesterol levels mainly due to increased catabolism of LDL particles through LDL receptors, decreases lipoprotein a (Lp(a)) levels owing to a decreased Apo (a) production and, finally, decreases modestly triglyceride (TRG) levels due to increased lipolysis and increased receptor-mediated catabolism of TRG-rich particles. Interestingly, anacetrapib may be associated with a beneficial effect on carbohydrate homeostasis. Furthermore, the Randomized EValuation of the Effects of Anacetrapib Through Lipid-modification (REVEAL) trial showed that anacetrapib administration on top of statin treatment significantly reduces cardiovascular events in patients with atherosclerotic vascular disease without any significant increase of adverse events despite its long half-life. Thus, anacetrapib could be useful for the effective management of dyslipidemias in high-risk patients that do not attain their LDL cholesterol target or are statin intolerable, while its role in patients with increased Lp(a) levels remains to be established.