Proprotein Convertase Subtilisin/kexin Type 9 Antibodies Research Articles

PCSK9 inhibitors as a new modality for treating dyslipidemia

Managing dyslipidemia is a crucial approach to reducing the likelihood of developing atherosclerotic cardiovascular disease. The Food and Drug Administration has approved Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors for the treatment of dyslipidemia. This study provides a comprehensive overview of the latest information on developing medicines that target PCSK9 to decrease cholesterol levels. PCSK9 attaches to the low-density lipoprotein (LDL) receptor, leading to the receptor\'s breakdown in the lysosome. Individuals with gain-of-function mutations in PCSK9 exhibit reduced expression of LDL receptors on the surface of hepatocytes, leading to elevated levels of LDL cholesterol (LDL-C). Conversely, mutations that cause PCSK9 to lose its activity are linked to reduced levels of LDL-C and a notably decreased lifetime risk of cardiovascular disease.Monoclonal antibodies that target PCSK9, such as evolocumab and alirocumab, were created and found to significantly decrease LDL-C by as much as 60% in various populations, whether used alone or in conjunction with statins. These findings have expanded the range of pharmaceutical methods available for managing the remaining cardiovascular risk associated with LDL-C. PCSK9 antibodies exhibit a low risk of adverse effects. Emerging strategies for blocking PCSK9 show great potential. Novel PCSK9 inhibitors have been researched and are being implemented for therapeutic applications. Additional clinical trials are necessary to yield valuable data regarding the effectiveness of these substances and their function in the treatment of dyslipidemia.

Feasibility of Short-Term Aggressive Lipid-Lowering Therapy with the PCSK9 Antibody in Acute Coronary Syndrome.

The guideline-recommended low-density lipoprotein cholesterol target level of <70 mg/dL may not be achieved with statin administration in some patients with acute coronary syndrome (ACS). Therefore, the proprotein convertase subtilisin-kexin type 9 (PCSK9) antibody can be added to high-risk patients with ACS. Nevertheless, the optimal duration of PCSK9 antibody administration remains unclear. Patients were randomized to receive either 3 months of lipid lowering therapy (LLT) with the PCSK9 antibody followed by conventional LLT (with-PCSK9-antibody group) or 12 months of conventional LLT alone (without-PCSK9-antibody group). The primary endpoint was the composite of all-cause death, myocardial infarction, stroke, unstable angina, and ischemia-driven revascularization. A total of 124 patients treated with percutaneous coronary intervention (PCI) were randomly assigned to the two groups (n = 62 in each). The primary composite outcome occurred in 9.7% and 14.5% of the patients in the with- and without-PCSK9-antibody groups, respectively (hazard ratio: 0.70; 95% confidence interval: 0.25 to 1.97; p = 0.498). The two groups showed no significant differences in hospitalization for worsening heart failure and adverse events. In ACS patients who underwent PCI, short-term PCSK9 antibody therapy with conventional LLT was feasible in this pilot clinical trial. Long-term follow-up in a larger scale clinical trial is warranted.

Association of high proprotein convertase subtilisin/kexin type 9 antibody level with poor prognosis in patients with diabetes: a prospective study

In addition to pathogenic autoantibodies, polyclonal autoantibodies with unknown physiological roles and pathogenicity are produced in the body. Moreover, serum antibodies against the proprotein convertase subtilisin/kexin type 9 (PCSK9) protein, which is integral to cholesterol metabolism, have also been observed. PCSK9 was also reported to be associated with insulin secretion and diabetes mellitus (DM). Therefore, we aimed to examine the clinical significance of PCSK9 antibodies (PCSK9-Abs) levels. We measured blood PCSK9-Abs and PCSK9 protein levels in 109 healthy donors (HDs) and 274 patients with DM (type 2 DM: 89.8%) using an amplified luminescence proximity homogeneous assay-linked immunosorbent assay. Subsequently, patients with DM were followed up (mean: 4.93 years, standard deviation: 2.77 years, maximum: 9.58 years, minimum: 0.07 years) to examine associations between antibody titers and mortality, myocardial infarction, stroke onset, and cancer. The primary endpoint of this study was to examine whether PCSK9-Abs can be a prognostic marker for overall mortality among the patients with diabetes. The secondary endpoint was to examine the relationship between PCSK9-Abs and clinical parameters. Although both PCSK9-Abs and PCSK9 protein levels were significantly higher in the DM group than in the HD group (p < 0.008), PCSK9-Abs and PCSK9 protein levels showed no correlation in either group. Mortality was significantly associated with higher PCSK9-Ab levels, but unrelated to PCSK9 protein levels. After investigating for potential confounding factors, higher PCSK9-Ab levels were still associated with increased mortality among the patients with DM. PCSK9-Abs may be a novel prognostic marker for overall mortality in patients with diabetes, and further studies are warranted to verify its usefulness.

Moderne Lipidsenker – ein Mittel gegen das Problem der Unterversorgung?

An elevated low-density lipoproteincholesterol (LDL-C) level is one of the most important modifiable cardiovascular risk factors. Despite potent combination treatment, the LDL‑C target values are not achieved in many high-risk patients. Presentation of the rationale for lowering LDL‑C, the current status of lipid-lowering treatment and established and novel approaches to lower LDL‑C. Based on the large outcome trials with ezetimibe and antibodies against proprotein convertase subtilisin-kexin type 9 (PCSK9), the professional societies recommend LDL‑C target values depending on the individual cardiovascular risk. For patients with manifest atherosclerosis, the LDL‑C target value is < 55 mg/dL (1.4 mmol/L). The LDL‑C target values are only achieved in the minority of patients. The reasons for this include alack of awareness among treating physicians, low medication adherence, restrictions in prescriptions and intolerance. On the basis of ahealthy lifestyle, statins are the cornerstone of LDL-C-lowering treatment. If LDL‑C targets are not achieved, the cholesterol absorption inhibitor ezetimibe is additionally recommended. As a third step, PCSK9 antibodies are added. Anovel drug to lower LDL‑C is the orally available bempedoic acid, which acts on the same metabolic pathway as statins but is specifically activated in the liver and not in the skeletal muscle. Another novel drug is inclisiran, which acts as an intracellular PCSK9 inhibitor through RNA interference. Inclisiran is administered subcutaneously only every 6months and has potential advantages regarding adherence. According to the new recommendations, active substances should be combined and fixed-dose combinations should be used early for lowering of LDL‑C. Using established and novel LDL-C-lowering drugs, the recommended LDL‑C target values can be achieved in the majority of patients with a high cardiovascular risk.

Abstract 10516: Identification of a PCSK9-LDLR Disruptor Macrocycle with in vivo Function

Elevated LDL-C is a major risk factor for atherosclerotic cardiovascular disease, the leading cause of death worldwide. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has pronounced effects on LDL-C levels via its modulation of hepatic LDL receptors (LDLR), the main pathway for cholesterol removal from the circulation. The epidermal growth factor precursor homology domain A (EGF-A) of the LDLR serves as a primary contact with PCSK9 via a flat interface, presenting a challenge for identifying small molecule PCSK9-LDLR disruptors. We employed an affinity-based screen of 10 13 in vitro -translated macrocyclic peptides to identify high affinity PCSK9 ligands that utilize a novel, induced-fit pocket and partially disrupt the PCSK9-LDLR interaction (Hit 1 - PCSK9-LDLR FRET, IC 50 2 nM, A max 41%). Structure-based design led to 13 PCSK9i , a molecule with enhanced in vitro function (PCSK9-LDLR FRET, IC 50 2 nM, A max 78%) and pharmacokinetic properties suitable for in vivo evaluation. To determine if 13 PCSK9i ’s functional activity in vitro would translate in vivo , C57BL/6 mice were dosed with vehicle or 13 PCSK9i via subcutaneous injection twice-daily for 3 days, and blood and liver were collected for the measurement of plasma total cholesterol (TC) and hepatic LDLR density. A PCSK9 antibody was included as a positive control. As illustrated in the figure, 13 PCSK9i increased hepatic LDLR density in a dose-dependent manner. Despite being 1/100 th its size, 13 PCSK9i (MW = 1.65 kDa) increased hepatic LDLR density on par with a PCSK9 antibody (MW = 144 kDa). Plasma TC levels were significantly reduced versus vehicle in all 13 PCSK9i dose groups, with similar reductions noted in the 13 PCSK9i 30 mg/kg and PCSK9 antibody groups (44% and 48%, respectively). In summary, 13 PCSK9i breaks new ground with its previously undescribed allosteric mechanism and, in turn, as the smallest molecule identified to date with in vivo PCSK9-LDLR disruptor function.

Association of Serum Anti-PCSK9 Antibody Levels with Favorable Postoperative Prognosis in Esophageal Cancer.

BackgroundEsophageal cancer often appears as postoperative metastasis or recurrence after radical surgery. Although we had previously reported that serum programmed cell death ligand 1 (PD-L1) level correlated with the prognosis of esophageal cancer, further novel biomarkers are required for more precise prediction of the prognosis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is associated with the cholesterol metabolism. But there was no report of relationship between serum PCSK9 antibody and cancer. Therefore, we investigated whether anti-PCSK9 antibodies could be a novel biomarker for solid cancer.MethodsSerum levels of anti-PCSK9 antibodies and antigens in patients with solid cancer were analyzed using amplified luminescence proximity homogeneous assay-linked immunosorbent assay (AlphaLISA). The reactivity of serum antibodies against recombinant PCSK9 protein was investigated by Western blotting, and the expression of PCSK9 antigens in esophageal cancer tissues was examined by immunohistochemical staining.ResultsAlphaLISA showed that serum anti-PCSK9 antibody (s-PCSK9-Ab) levels were significantly higher in patients with esophageal cancer, gastric cancer, colorectal cancer, lung cancer, and breast cancer than in healthy donors, and patients with esophageal cancer had the highest levels. The presence of serum antibody in patients was confirmed by Western blotting. There was no apparent correlation between s-PCSK9-Ab and PCSK9 antigen levels. Immunohistochemical staining demonstrated the expression of PCSK9 antigen in both the cytoplasm and nuclear compartments of esophageal squamous cell carcinoma tissue but not in normal tissue. Compared with patients with low s-PCSK9-Ab levels, those with high s-PCSK9-Ab levels had a favorable postoperative prognosis after radical surgery for esophageal cancer. In the multivariate analysis, tumor depth and s-PCSK9-Ab level were identified as independent prognostic factors. In the univariate analysis of clinicopathological features, high PCSK9 antibody levels were not associated with sex, age, location, tumor depth, lymph node status, squamous cell carcinoma antigen, or p53-Ab, whereas they correlated significantly with PD-L1 levels, which were associated with unfavorable prognosis. Correlation between s-PCSK9-Ab and PD-L1 levels was also confirmed in the logistic regression analysis; therefore, low s-PCSK9-Ab levels could discriminate another poor prognosis group other than high-PD-L1 group.ConclusionsPatients with solid cancer had higher s-PCSK9-Ab levels than healthy donors. High s-PCSK9-Ab levels indicated better prognosis for overall survival after surgery in patients with esophageal cancer.

Effects of the PCSK9 antibody alirocumab on coronary atherosclerosis in patients with acute myocardial infarction: a serial, multivessel, intravascular ultrasound, near-infrared spectroscopy and optical coherence tomography imaging study–Rationale and design of the PACMAN-AMI trial

The risk for cardiovascular adverse events after acute myocardial infarction (AMI) remains high despite potent medical treatment including low-density lipoprotein cholesterol (LDL-C) lowering with statins. Proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies substantially reduce LDL-C when added to statin. Alirocumab, a monoclonal antibody to PCSK9, reduces major adverse cardiovascular events after AMI. The effects of alirocumab on coronary atherosclerosis including plaque burden, plaque composition and fibrous cap thickness in patients presenting with AMI remains unknown. To determine the effect of LDL-C lowering with alirocumab on top of high-intensity statin therapy on intravascular ultrasound (IVUS)-derived percent atheroma volume (PAV), near-infrared spectroscopy (NIRS)-derived maximum lipid core burden index within 4 mm (maxLCBI4 mm) and optical coherence tomography (OCT)-derived fibrous cap thickness (FCT) in patients with AMI. In this multicenter, double-blind, placebo-controlled trial, 300 patients with AMI (ST-elevation or non-ST-elevation myocardial infarction) were randomly assigned to receive either biweekly subcutaneous alirocumab (150 mg) or placebo beginning <24 hours after the acute event as add-on therapy to rosuvastatin 20 mg. Patients undergo serial IVUS, NIRS and OCT in the two non-infarct related arteries at baseline (at the time of treatment of the culprit lesion) and at 52 weeks. The primary endpoint, change in IVUS-derived PAV, and the powered secondary endpoints, change in NIRS-derived maxLCBI4 mm, and OCT-derived minimal FCT, will be assessed 52 weeks post randomization. The PACMAN-AMI trial will determine the effect of alirocumab on top of high-intensity statin therapy on high-risk coronary plaque characteristics as assessed by serial, multimodality intracoronary imaging in patients presenting with AMI. NCT03067844.

PCSK9 Inhibition: Insights From Clinical Trials and Future Prospects.

In 2003, clinical observations led to the discovery of the involvement of proprotein convertase subtilisin/kexin type 9 (PCSK9) in lipid metabolism. Functional studies demonstrated that PCSK9 binds to the low-density lipoprotein (LDL) receptor directing it to its lysosomal degradation. Therefore, carriers of gain-of-function mutations in PCSK9 exhibit decreased expression of LDL receptors on the hepatocyte surface and have higher LDL cholesterol (LDL-C) levels. On the contrary, loss-of-function mutations in PCSK9 are associated with low LDL-C concentrations and significantly reduced lifetime risk of cardiovascular disease. These insights motivated the search for strategies to pharmacologically inhibit PCSK9. In an exemplary rapid development, fully human monoclonal antibodies against PCSK9 were developed and found to effectively reduce LDL-C. Administered subcutaneously every 2–4 weeks, the PCSK9 antibodies evolocumab and alirocumab reduce LDL-C by up to 60% in a broad range of populations either as monotherapy or in addition to statins. Two large cardiovascular outcome trials involving a total of ∼46,000 cardiovascular high-risk patients on guideline-recommended lipid-lowering therapy showed that treatment with evolocumab and alirocumab led to a relative reduction of cardiovascular risk by 15% after 2.2 and 2.8 years of treatment, respectively. These findings expanded the armamentarium of pharmacological approaches to address residual cardiovascular risk associated with LDL-C. Furthermore, the unprecedented low LDL-C concentrations achieved (e.g., 30 mg/dL in the FOURIER study) suggest that the relationship between LDL-C and cardiovascular risk is without a lower threshold, and without associated adverse events during the timeframe of the studies. The side effect profile of PCSK9 antibodies is favorable with few patients exhibiting injection-site reactions. Currently, the access to PCSK9 antibodies is limited by high treatment costs. The development of novel approaches to inhibit PCSK9 such as the use of small interfering RNA to inhibit PCSK9 synthesis seems promising and may soon become available.

Potent lipoprotein(a) lowering following apolipoprotein(a) antisense treatment reduces the pro-inflammatory activation of circulating monocytes in patients with elevated lipoprotein(a).

AimsElevated lipoprotein(a) [Lp(a)] is strongly associated with an increased cardiovascular disease (CVD) risk. We previously reported that pro-inflammatory activation of circulating monocytes is a potential mechanism by which Lp(a) mediates CVD. Since potent Lp(a)-lowering therapies are emerging, it is of interest whether patients with elevated Lp(a) experience beneficial anti-inflammatory effects following large reductions in Lp(a).Methods and resultsUsing transcriptome analysis, we show that circulating monocytes of healthy individuals with elevated Lp(a), as well as CVD patients with increased Lp(a) levels, both have a pro-inflammatory gene expression profile. The effect of Lp(a)-lowering on gene expression and function of monocytes was addressed in two local sub-studies, including 14 CVD patients with elevated Lp(a) who received apolipoprotein(a) [apo(a)] antisense (AKCEA-APO(a)-LRx) (NCT03070782), as well as 18 patients with elevated Lp(a) who received proprotein convertase subtilisin/kexin type 9 antibody (PCSK9ab) treatment (NCT02729025). AKCEA-APO(a)-LRx lowered Lp(a) by 47% and reduced the pro-inflammatory gene expression in monocytes of CVD patients with elevated Lp(a), which coincided with a functional reduction in transendothelial migration capacity of monocytes ex vivo (−17%, P < 0.001). In contrast, PCSK9ab treatment lowered Lp(a) by 16% and did not alter transcriptome nor functional properties of monocytes, despite an additional reduction of 65% in low-density lipoprotein cholesterol (LDL-C).ConclusionPotent Lp(a)-lowering following AKCEA-APO(a)-LRx, but not modest Lp(a)-lowering combined with LDL-C reduction following PCSK9ab treatment, reduced the pro-inflammatory state of circulating monocytes in patients with elevated Lp(a). These ex vivo data support a beneficial effect of large Lp(a) reductions in patients with elevated Lp(a).

P5328Clinical and demographic predictors of attenuated LDL-C response to PCSK9 inhibition with bococizumab: Insights from the SPIRE trials

Abstract Background While there exists significant inter-individual variability in low density lipoprotein cholesterol (LDL-C) response to proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition, predictors of this response remain uncertain. The Studies of PCSK9 Inhibition and the Reduction of Vascular Events (SPIRE) randomized control trials evaluated the efficacy of bococizumab, a humanized murine PCSK9 antibody, in patients at high cardiovascular risk. Purpose This study's purpose is to determine predictors of attenuated LDL-C response to bococizumab. Methods SPIRE 1 and 2 trial subjects allocated to bococizumab (n=13,675) were included. Subjects with an increase in LDL-C or non-compliance to bococizumab, or development of anti-drug or neutralizing antibodies were excluded. The remaining 8281 subjects were divided into quintiles of percent LDL-C reduction from baseline to 14 weeks. The first quintile (Q1) was considered an attenuated response. Multivariate logistic regression was used to discern significant predictors of attenuated response (Q1) compared to robust response (Q5). Results Q1 included 1657 subjects with median 35% LDL-C reduction (range 0.4% - 48%), whereas Q5 included 1658 subjects with median 83% LDL-C reduction (range 78% - 99%). Female sex, diabetes, white race, younger age, higher baseline non-high-density lipoprotein cholesterol (non-HDL-C), lipoprotein (a) [Lp(a)] and high-sensitivity C-reactive protein (hsCRP) were significantly associated with an attenuated response compared to a robust response (each p&lt;0.05, Table). Multivariate logistic regression for attenuated percent LDL-C response to bococizumab from baseline to 14 week Baseline characteristic Adjusted odds ratio (95% confidence interval) P-value Female 3.30 (2.72, 4.00) &lt;0.0001 Diabetes 1.57 (1.32, 1.86) &lt;0.0001 White race 1.44 (1.07, 1.93) 0.016 BMI (per 1kg/m2) 1.09 (1.07, 1.11) &lt;0.0001 Age (per year) 0.98 (0.98, 0.99) 0.0005 Ln hs-CRP (per 1mg/L) 1.19 (1.11, 1.29) &lt;0.0001 Lp (a) (per 10mg/dL) 1.11 (1.09, 1.14) &lt;0.0001 Non-HDL-C (per 10mg/dL) 1.05 (1.02, 1.07) &lt;0.0001 Odds ratios mutually adjusted for the listed variables. Conclusions In the SPIRE 1 and 2 trials, excluding subjects with anti-drug and neutralizing antibodies, significant predictors of an attenuated LDL-C response to PCSK9 inhibition with bococizumab included female sex, diabetes, younger age and white race. Acknowledgement/Funding Pfizer

PCSK9 Hapten Multicopy Displayed onto Carrier Protein Nanoparticle: An Antiatherosclerosis Vaccine.

In recent years, various vaccination strategies have shed new light on the treatment of atherosclerosis. Proprotein convertase subtilisin/Kexin type 9 (PCSK9) is a hot target in the development of antiatherosclerosis vaccine. However, the efficacy of conventional PCSK9 is largely limited by poor immunogenicity and low hapten density. Therefore, we hypothesized whether a nanostructure synthesized by self-assembled carrier protein accompanied by multicopy hapten display could improve the efficacy of vaccine. In this study, bovine serum albumin (BSA) was self-assembled into sub-100 nm nanoparticles via an intermolecular disulfide network as the inner core. Then, sequences of PCSK9 were conjugated onto the surface of nanoparticles by "click" chemistry to consequently form an orderly structured of nanovaccine with repetitive hapten display. Compared with conventional PCSK9 peptide vaccine, our immunization study demonstrated that the PCSK9 multicopy display nanovaccine (PMCDN) was able to induce higher titers of PCSK9 antibody and more efficient lymph node drainage and improve endocytosis by antigen presenting cells.

Real-world study: Escalating targeted lipid-lowering treatment with PCSK9-inhibitors and lipoprotein apheresis.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition with monoclonal antibodies has complemented the armamentarium of lipid-lowering therapy (LLT) before the final step of commencing chronic lipoprotein apheresis (LA). Data are scarce on patients who, after escalation of LLT with PCSK9 antibodies, have commenced chronic LA or PCSK9 antibody treatment during ongoing long-term LA. In this study, a cohort of 110 patients with established atherosclerotic cardiovascular disease (ASCVD) due to hypercholesterolemia or concomitant lipoprotein(a)-hyperlipoproteinemia, who received PCSK9 antibodies for the first time during routine care, were consecutively identified. Mean LDL-C concentration prior to initiation of LA or PCSK9 antibody treatment was 5.3 ± 2.6 mmol/L (205 ± 102 mg/dL). Due to established ASCVD, the risk-adjusted LDL-C target value was <1.8 mmol/L (<70 mg/dL) in all patients. Use of PCSK9 antibodies increased the proportion of patients attaining the LDL-C target concentration by 41.8% overall. Treatment emergent adverse events (TEAE) associated with PCSK9 antibody medication were reported in 35 patients (31.8%). Discontinuation of PCSK9 antibody therapy due to TEAEs occurred in 25 patients (22.7%). Finally, 55.5% of patients received a combination of PCSK9 antibody therapy and LA at individually optimized treatment frequencies resulting in an increase of target attainment in 54.1% of patients. About 18.1% of chronic LA patients terminated LA treatment in this real-world study. The termination of long-term LA therapy, which has hitherto prevented the progression of ASCVD, requires careful individual risk assessment and cannot be recommended by the general criteria of LDL-C reduction.

The Role of PCSK9 in the Pathogenesis of Non-alcoholic Fatty Liver Disease and the Effect of PCSK9 Inhibitors.

Statin treatment exhibits a beneficial effect on non-alcoholic fatty liver disease (NAFLD) and on cardiovascular disease (CVD) in patients with NAFLD. The aim of this review is to summarize the role of proprotein convertase subtilisin kexin type- 9(PCSK9) in the pathogenesis of NAFLD and discuss the effects of the new hypolipidaemic drugs PCSK9 inhibitors on NAFLD. Data indicates that high intrahepatic or circulating PCSK9 levels increase muscle and liver lipid storage, adipose energy storage and hepatic fatty acids, as well as triglycerides storage and secretion, thus contributing to the pathogenesis of NAFLD. The findings of animal and human studies, aiming to reduce PCSK9 with inhibitors (human IGG antibodies, antisense particles against PCSK9 mRNA, and small anti PCSK9 antibodies) point towards liver protection from NAFLD through inhibition of PCSK9 expression in the induction of degradation of hepatic HNF1a protein, insulin resistance (IR), and other mechanisms. The use of PCSK9 inhibitors ameliorates NAFLD, aside from beneficial effects on CVD and independently of low density lipoprotein cholesterol level reduction.

Novel aspects of PCSK9 and lipoprotein receptors in renal disease-related dyslipidemia

Chronic kidney disease (CKD) is a global health problem with a profound impact on quality of life. Cardiovascular disease is established as a major cause of morbidity and mortality in patients with CKD. Dyslipidemia is frequently observed in CKD patients, suggesting a causal relation between dyslipidemia and cardiovascular disease in CKD patients. Currently, lipid-lowering drugs such as statins, are the primary choice for lipid lowering therapy in high-risk populations. Despite many studies showing CVD risk reduction with statins, CVD still remains the leading cause of the death in CKD. This underscores the need for new therapeutic approaches to reduce cardiovascular risk in CKD patients. Reduced lipoprotein lipase activity, increased very low-density lipoprotein production, increased proprotein convertase subtilisin kexin type 9 (PCSK9) expression and loss of hepatic heparan sulfate proteoglycans (HSPG) syndecan-1 have been associated with CKD-related dyslipidemia. Low-density lipoprotein receptor (LDLR), low-density lipoprotein receptor-related protein 1 (LRP-1) and syndecan-1, are the most important hepatic receptors for lipoprotein clearance. However, their contributions to the pathogenesis of dyslipidemia and cardiovascular disease in CKD remain unclear. Interestingly, in CKD, increased plasma lipid levels are associated with elevated levels of PCSK9. This promotes the proteolysis of LDLR, suggesting a role for PCSK9 in CKD-associated dyslipidemia. Fully humanized monoclonal antibodies targeting PCSK9 have been approved by the US Food and Drug Administration and the European Medicines Agency as lipid lowering treatment for patients with hypercholesterolemia. In CKD sub-group analysis, ODYSSEY COMBO I and ODYSSEY COMBO II studies demonstrated strong reduction in LDL-C by alirocumab compared to placebo and ezetimibe and when added to statins. However, their efficacy in reducing plasma TG is controversial. Therefore, further research work is need for a detailed analysis on efficacy and safety of PCSK9 antibodies in CKD groups. Interestingly, novel findings on PCSK9 interaction with HSPG might shed new insight on altered lipid metabolism in CKD. In this review, we discuss various aspects of lipoprotein metabolism and hepatic lipoprotein receptor signaling pathways along with the concept of renal disease-related dyslipidemia. Furthermore, this review highlights the drawbacks of current lipid-lowering therapies and proposes novel approaches for lipid management in CKD.

Development of Novel DNA-Encoded PCSK9 Monoclonal Antibodies as Lipid-Lowering Therapeutics.

Elevated low-density lipoprotein cholesterol (LDL-C) is one of the major contributors to cardiovascular heart disease (CHD), the leading cause of death worldwide. Due to severe side effects of statins, alternative treatment strategies are required for statin-intolerant patients. Monoclonal antibodies (mAbs) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) have shown great efficacy in LDL-C reduction. Limitations for this approach include the need for multiple injections as well as increased costs associated with patient management. Here, we engineered a DNA-encoded mAb (DMAb) targeting PCSK9 (daPCSK9), as an alternative approach to protein-based lipid-lowering therapeutics, and we characterized its expression and activity. A single intramuscular administration of mouse daPCSK9 generated expression in vivo for over 42 days that corresponded with a substantial decrease of 28.6% in non-high-density lipoprotein cholesterol (non-HDL-C) and 10.3% in total cholesterol by day 7 in wild-type mice. Repeated administrations of the DMAb plasmid led to increasing expression, with DMAb levels of 7.5 μg/mL at day 62. daPCSK9 therapeutics may provide a novel, simple, less frequent, cost-effective approach to reducing LDL-C, either as a stand-alone therapy or in combination with other LDL-lowering therapeutics for synergistic effect.

PCSK9-Inhibitor treatment of cardiovascular high risk patients in clinical practice – New data regarding safety and effectivity

Aim: Only recently, Proprotein convertase subtilisin/kexin type 9 antibodies (PCSK9-I) became available to treat therapy-refractory hypercholesterolemia. The aim of this study is to provide new safety and efficacy data of PCSK9-I collected in clinical practice, with particular regard to subgroups in patients with diabetes mellitus or high Lp(a).

Generation and Characterization of a Novel Small Biologic Alternative to Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Antibodies, DS-9001a, Albumin Binding Domain-Fused Anticalin Protein.

Since it was recently reported that an antibody for proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces the risk of cardiovascular events in a clinical context, PCSK9 inhibition is thought to be an attractive therapy for dyslipidemia. In the present study, we created a novel small biologic alternative to PCSK9 antibodies called DS-9001a, comprising an albumin binding domain fused to an artificial lipocalin mutein (ABD-fused Anticalin protein), which can be produced by a microbial production system. DS-9001a strongly interfered with PCSK9 binding to low-density-lipoprotein receptor (LDL-R) and PCSK9-mediated degradation of LDL-R. In cynomolgus monkeys, single DS-9001a administration significantly reduced the serum LDL-C level up to 21 days (62.4% reduction at the maximum). Moreover, DS-9001a reduced plasma non-high-density-lipoprotein cholesterol and oxidized LDL levels, and their further reductions were observed when atorvastatin and DS-9001a were administered in combination in human cholesteryl ester transfer protein/ApoB double transgenic mice. Additionally, their reductions on the combination of atorvastatin and DS-9001a were more pronounced than those on the combination of atorvastatin and anacetrapib. Besides its favorable pharmacologic profile, DS-9001a has a lower molecular weight (about 22 kDa), yielding a high stoichiometric drug concentration that might result in a smaller administration volume than that in existing antibody therapy. Since bacterial production systems are viewed as more suited to mass production at low cost, DS-9001a may provide a new therapeutic option to treat patients with dyslipidemia. In addition, considering the growing demand for antibody-like drugs, ABD-fused Anticalin proteins could represent a promising new class of small biologic molecules.

Effect of cholesterol lowering with statins or proprotein convertase subtilisin/kexin type 9 antibodies on cataracts: A meta-analysis

It is not known whether statins or proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies are associated with cataract and whether very low achieved low-density lipoprotein cholesterol (LDL-C) lowering may cause cataract. To examine two questions: whether statins and/or PCSK9 antibodies cause or prevent cataracts and whether very low LDL-C is associated with increased risk of cataract. Systematic searches of PubMed, ClinicalTrials.gov, Web of Science, The Cochrane Library, and an Federal Drug Administration report were used to perform random effects meta-analyses on the relationship of statins and/or PCSK9 antibodies with cataract. These meta-analyses were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Prespecified analyses indicated no significant effect of statins or PCSK9 antibodies (odds ratio [OR] 0.99, 95% confidence interval [CI] 0.83-1.17, P=.8889) or differences between the effects of statins (OR 0.89, 95% CI 0.66-1.19, P=.4349) and PCSK9 antibodies (OR 1.04, 95% CI 0.85-1.28, P=.7042) on the development of cataract. Also, there was no significant effect of LDL-C lowering to different levels with respect to cataract (OR 1.06, 95% CI 0.92-1.22, P=.4317). Meta-regression of the log OR for cataract vs LDL-C during treatment did not show a statistically significant relationship (P for slope=.3972). There was no significant effect of cholesterol lowering with statins or PCSK9 antibodies or differences between these two medication classes in causing or preventing cataracts. However, it is difficult to make definitive statements regarding PCSK9 antibodies because there is no long-term experience with these agents. Very low LDL-C was not associated with higher risk of cataract.

PCSK9 inhibition alters the lipidome of plasma and lipoprotein fractions

Background and aimsWhile inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) is known to result in dramatic lowering of LDL-cholesterol (LDL-C), it is poorly understood how it affects other lipid species and their metabolism. The aim of this study was to characterize the alterations in the lipidome of plasma and lipoprotein particles after administration of PCSK9 inhibiting antibody to patients with established coronary heart disease. MethodsPlasma samples were obtained from patients undergoing a randomized placebo-controlled phase II trial (EQUATOR) for the safe and effective use of RG7652, a fully human monoclonal antibody inhibiting PCSK9 function. Lipoprotein fractions were isolated by sequential density ultracentrifugation, and both plasma and major lipoprotein classes (VLDL-IDL, LDL, HDL) were subjected to mass spectrometric lipidomic profiling. ResultsPCSK9 inhibition significantly decreased plasma levels of several lipid classes, including sphingolipids (dihydroceramides, glucosylceramides, sphingomyelins, ceramides), cholesteryl esters and free cholesterol. Previously established ceramide ratios predicting cardiovascular mortality, or inflammation related eicosanoid lipids, were not altered. RG7652 treatment also affected the overall and relative distribution of lipids in lipoprotein classes. An overall decrease of total lipid species was observed in LDL and VLDL + IDL particles, while HDL-associated phospholipids increased. Following the treatment, LDL displayed reduced lipid cargo, whereas relative lipid proportions of the VLDL + IDL particles were mostly unchanged, and there were relatively more lipids carried in the HDL particles. ConclusionsAdministration of PCSK9 antibody significantly alters the lipid composition of plasma and lipoprotein particles. These changes further shed light on the link between anti-PCSK9 therapies and cardiovascular risk.

Management of Severe Dyslipidaemia: Role of PCSK9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays an important role in regulation of LDL receptors on the hepatocyte surface and therefore is essential for effective removal of LDL particles from circulation. Genetic and biochemical studies have established that altered PCSK9 functionality influences both LDL cholesterol levels and cardiovascular risk. This has prompted development of inhibitory strategies targeting PCSK9. Study of monoclonal PCSK9 antibodies has progressed to the clinic, where they have been found to lower LDL cholesterol levels and reduce cardiovascular event rates in large, clinical outcome trials. The use of PCSK9 inhibitors in the setting of dyslipidaemia is reviewed.