PCSK9 Inhibition: New Treatment Options and Perspectives to Lower Atherogenic Lipoprotein Particles and Cardiovascular Risk

PCSK9 inhibitors on the management of primary and secondary cardiovascular prevention

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have represented an important change in the management of hypercholesterolemia, although, until now, they have barely been used. Without PCSK9i, many patients with atherosclerotic cardiovascular disease (CVD) or those at very high risk do not reach their therapeutic LDLc objectives.

OBJECTIVE

The analysis aimed to examine the clinical and biochemical characteristics of subjects receiving PCSK9i treatment in the Dyslipidemia Registry of the Spanish Atherosclerosis Society.

METHODS

All consecutive subjects aged ≥ 18 years from different Lipid Units included in the Dyslipidemia Registry of the SEA were analyzed. Inclusion criteria consisted of unrelated patients aged ≥ 18 at the time of inclusion with hypercholesterolemia (LDL-C ≥ 130 mg/dL or non-HDL-C ≥ 160 mg/dL after the exclusion of secondary causes) who were studied for at least two years after inclusion. Participants' baseline and final visit clinical and biochemical characteristics were analyzed based on whether they were on primary or secondary prevention and whether they were taking PCSK9i at the end of follow-up.

RESULTS

Eight hundred twenty-nine patients were analyzed, 7014 patients in primary prevention and 1281 in secondary prevention at baseline. 4127 subjects completed the required follow-up for the final analysis. The median follow-up duration was 7 years (IQR 3.0-10.0). Five hundred patients (12.1%) were taking PCSK9i at the end of the follow-up. The percentage of PCSK9i use reached 35.6% (n = 201) and 8.7% (n = 318) in subjects with and without CVD, respectively. Subjects on PCSK9i and oral lipid-lowering agents with and without CVD achieved LDLc reductions of 80.3% and 75.1%, respectively, concerning concentrations without lipid-lowering drugs. Factors associated with PCSK9i use included increasing age, LDLc without lipid-lowering drugs and the Dutch Lipid Clinic Network (DLCN) score. However, hypertension, diabetes, smoking, and LDLc after oral lipid-lowering drugs were not independent factors associated with PCSK9i prescription. In subjects with CVD, the use of PCSK9i was higher in men than in women (an odds ratio of 1.613, P = 0.048).

CONCLUSIONS

Approximately one-third of CVD patients received PCSK9i at the end of follow-up. The use of PCSK9i was more focused on baseline LDLc concentrations rather than on CVD risk. Women received less PCSK9i in secondary prevention compared to men.

Optimization of the MACE endpoint composition to increase power in studies of lipid-lowering therapies-a model-based meta-analysis

Aims

To develop a model-informed methodology for the optimization of the Major Adverse Cardiac Events (MACE) composite endpoint, based on a model-based meta-analysis across anti-hypercholesterolemia trials of statin and anti-PCSK9 drugs.

Methods and results

Mixed-effects meta-regression modeling of stand-alone MACE outcomes was performed, with therapy type, population demographics, baseline and change over time in lipid biomarkers as predictors. Randomized clinical trials up to June 28, 2022, of either statins or anti-PCSK9 therapies were identified through a systematic review process in PubMed and ClinicalTrials.gov databases. In total, 54 studies (270,471 patients) were collected, reporting 15 different single cardiovascular events. Treatment-mediated decrease in low density lipoprotein cholesterol, baseline levels of remnant and high-density lipoprotein cholesterol as well as non-lipid population characteristics and type of therapy were identified as significant covariates for 10 of the 15 outcomes. The required sample size per composite 3- and 4-point MACE endpoint was calculated based on the estimated treatment effects in a population and frequencies of the incorporated events in the control group, trial duration, and uncertainty in model parameters.

Conclusion

A quantitative tool was developed and used to benchmark different compositions of 3- and 4-point MACE for statins and anti-PCSK9 therapies, based on the minimum population size required to achieve statistical significance in relative risk reduction, following meta-regression modeling of the single MACE components. The approach we developed may be applied towards the optimization of the design of future trials in dyslipidemia disorders as well as in other therapeutic areas.

PCSK9 Inhibitor Wars: How Does Inclisiran Fit in with Current Monoclonal Antibody Inhibitor Therapy? Considerations for Patient Selection

PURPOSE OF REVIEW

Treatment of dyslipidemia represents one of the most crucial strategies to reduce risk of atherosclerotic cardiovascular (CV) disease (ASCVD). In this review, we critically summarize our knowledge on emerging cholesterol-lowering therapy, targeting PCSK9, paying particular attention on treatment allocation of two drug groups, currently available for clinical use, namely, anti-PCSK9 monoclonal antibodies (mAbs) and inclisiran, a first-in-class small interfering RNA against PCSK9.

RECENT FINDINGS

Although both drug classes show a pronounced, but fairly similar reduction in LDL-cholesterol, their long-term safety is still unknown. Compared to mAbs, inclisiran has a more favorable dosing regimen with biannual application that might improve therapeutic adherence significantly. However, a CV outcome trial (CVOT) for inclisiran is still missing. If inclisiran will be safe and effective in ongoing/future CVOTs, it has a huge potential to overcome medication non-compliance, thereby providing a powerful therapeutic option to decrease the burden of ASCVD.

Effect of PCSK9 Inhibitor on Blood Lipid Levels in Patients with High and Very-High CVD Risk: A Systematic Review and Meta-Analysis

Objectives

We aimed to investigate the effects of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor on blood lipid levels in patients with high and very-high cardiovascular risk.

Design

14 trials (n = 52,586 patients) comparing treatment with or without PCSK9 inhibitors were retrieved from PubMed and Embase updated to 1st Jun 2021. The data quality of included studies was assessed by two independent researchers using the Cochrane systematic review method. All-cause mortality, cardiovascular mortality, and changes in serum low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), apolipoprotein B (ApoB), lipoprotein (a) (LP (a)), non-high-density lipoprotein cholesterol (non-HDL-C), high-density lipoprotein cholesterol (HDL-C), and apolipoprotein A1 (ApoA1) from baseline were analyzed using Rev Man 5.1.0 software.

Results

Compared with treatments without PCSK9 inhibitor, addition of PCSK9 inhibitors (evolocumab and alirocumab) had obvious decreasing effects on the levels of LDL-C [MD = −46.86, 95% CI (−54.99 to −38.72), P < 0.00001], TC [MD = −31.92, 95% CI (−39.47 to −24.38), P < 0.00001], TG [MD = −8.13, 95% CI (−10.48 to −5.79), P < 0.00001], LP(a) [MD = −26.69, 95% CI (-27.93 to −25.44), P < 0.00001], non-HDL-C [MD = −42.86, 95% CI (−45.81 to −39.92), P < 0.00001], and ApoB [MD = −38.44, 95% CI (−42.23 to -34.65), P < 0.00001] in high CVD risk patients. Conversely, changes of HDL-C [MD = 6.27, CI (5.17 to 7.36), P < 0.00001] and ApoA1 [MD = 4.33, 95% CI (3.53 to 5.13), P < 0.00001] from baseline were significantly more in high cardiovascular disease risk patients who received PCSK9 inhibitors treatment.

Conclusion

Addition of PCSK9 inhibitors to standard therapy resulted in definite improvement in blood lipid levels compared with therapies that did not include them.

Circulating Proprotein Convertase Subtilisin/Kexin Type 9 Levels Predict Future Cardiovascular Event Risks in Hemodialyzed Black African Patients

CONTEXT AND OBJECTIVE

Cardiovascular diseases are the leading cause of mortality in patients. In this context, proprotein convertase subtilisin/kexin type 9 (PCSK9) appears to be the new biomarker identified as interfering in lipid homeostasis. This study aimed to investigate the association between PCSK9, dyslipidemia, and future risk of cardiovascular events in a population of black Africans.

METHODS

A cross-sectional study was conducted between August 2016 and July 2020 in six hemodialysis centers in the city of Kinshasa, Democratic Republic of the Congo. Serum PCSK9 was measured by ELISA; lipid levels of 251 chronic kidney disease grade 5 (CKD G5) hemodialysis patients and the Framingham predictive instrument were used for predicting cardiac events.

RESULTS

Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and triglycerides (TG) were significantly increased in the tertile with the highest PCSK9. By contrast, high-density lipoprotein cholesterol (HDL-c) was significantly decreased in the same tertile. A strong positive and significant correlation was found between PCSK9 and TC, TG, and LDL-c. Negative and significant correlation was observed between PCSK9 and HDL-c. The levels of PCSK9, smoking, overweight, and atherogenic dyslipidemia were associated with future risks for cardiovascular events in univariate analysis. After adjustment, all these variables persisted as independent determinants of future risk for cardiovascular events. The probability of having a cardiovascular event in this population was independently associated with PCSK9 levels. Compared to the patients in the lowest PCSK9 tertile, patients with PCSK9 levels in the middle (aOR 5.9, 95% CI 2.06-17.3, P<0.001) and highest tertiles (aOR 8.9, 95% CI 3.02-25.08, P<0.001) presented a greater risk of cardiac event.

CONCLUSION

Increased PCSK9 serum levels are associated with higher levels of TC, LDL-c, and TG and lower levels of HDL-c in black African hemodialysis patients. Serum PCSK9 levels in these patients predict increased risk of cardiovascular events, independent of traditional potential confounders.

Deficiency of Nucleotide-binding oligomerization domain-containing proteins (NOD) 1 and 2 reduces atherosclerosis

Atherosclerosis is crucially fueled by inflammatory pathways including pattern recognition receptor (PRR)-related signaling of the innate immune system. Currently, the impact of the cytoplasmic PRRs nucleotide-binding oligomerization domain-containing protein (NOD) 1 and 2 is incompletely characterized. We, therefore, generated Nod1/Nod2 double knockout mice on a low-density lipoprotein receptor (Ldlr)-deficient background (= Ldlr-/-Nod1/2-/-) which were subsequently analyzed regarding experimental atherosclerosis, lipid metabolism, insulin resistance and gut microbiota composition. Compared to Ldlr-/- mice, Ldlr-/-Nod1/2-/- mice showed reduced plasma lipids and increased hepatic expression of the scavenger receptor LDL receptor-related protein 1 after feeding a high-fat diet for 12 weeks. Furthermore, intestinal cholesterol and its bacterial degradation product coprostanol were elevated in Ldlr-/-Nod1/2-/- mice, correlating with the increased abundance of Eubacterium coprostanoligenes as assessed by 3rd generation sequencing of the gut microbiota. Atherosclerotic plaques of Ldlr-/-Nod1/2-/- mice exhibited less lipid deposition and macrophage accumulation. Moreover, macrophages from Ldlr-/-Nod1/2-/- mice showed higher expression of the cholesterol efflux transporters Abca1 and Abcg1 and accordingly reduced foam cell formation. Deficiency of Nod1 and Nod2 led to reduced plaque lipid deposition and inflammatory cell infiltration in atherosclerotic plaques. This might be explained by diminished plasma lipid levels and foam cell formation due to altered expression of key regulators of the hepatic cholesterol pathway as well as differential intestinal cholesterol metabolism and microbiota composition.