Safety and Tolerability of PCSK9 Inhibitors: Current Insights

Unraveling the Nexus Between Ambient Air Pollutants and Cardiovascular Morbidity: Mechanistic Insights and Therapeutic Horizons

Air pollution poses a significant threat to cardiovascular health, contributing to the development and progression of various heart diseases. This review delves into the intricate relationship between ambient air pollutants and cardiovascular morbidity, elucidating the underlying mechanisms and exploring potential therapeutic approaches. We discuss the major types of air pollutants, including particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO), and their respective roles in exacerbating cardiovascular conditions. The review highlights the key mechanisms by which air pollutants adversely impact the cardiovascular system, including systemic inflammation, oxidative stress, endothelial dysfunction, autonomic nervous system imbalance, and dysregulation of blood coagulation and thrombosis. Vulnerable populations, including children, the elderly, and those with pre-existing health conditions, are disproportionately affected. Air quality regulations aim to mitigate these effects by reducing pollutant levels, with the overall goal of lowering cardiovascular morbidity and improving public health outcomes. Specifically, stringent regulations focus on curbing vehicular emissions and industrial pollutants and promoting cleaner energy sources. Recent data underscore the importance of addressing environmental and behavioral risk factors to prevent the growing global burden of cardiovascular disease. This review synthesizes the mechanistic pathways through which pollutants contribute to cardiovascular damage and highlights the urgent need for early detection strategies and targeted therapies. Improving public health through stricter air quality control measures and raising awareness of the health risks associated with pollution is crucial for mitigating the long-term cardiovascular impacts of air pollution.

Proprotein convertase subtilisin/kexin type 9 inhibitors in peripheral artery disease: A review of efficacy, safety, and outcomes

Peripheral artery disease (PAD) is a common condition characterized by atherosclerosis in the peripheral arteries, associated with concomitant coronary and cerebrovascular diseases. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are a class of drugs that have shown potential in hypercholesterolemic patients. This review focuses on the efficacy, safety, and clinical outcomes of PCSK9 inhibitors in PAD based on the literature indexed by PubMed. Trials such as FOURIER and ODYSSEY demonstrate the efficacy of evolocumab and alirocumab in reducing cardiovascular events, offering a potential treatment option for PAD patients. Safety evaluations from trials show few adverse events, most of which are injection-site reactions, indicating the overall safety profile of PCSK9 inhibitors. Clinical outcomes show a reduction in cardiovascular events, ischemic strokes, and major adverse limb events. However, despite these positive findings, PCSK9 inhibitors are still underutilized in clinical practice, possibly due to a lack of awareness among care providers and cost concerns. Further research is needed to establish the long-term effects and cost-effectiveness of PCSK9 inhibitors in PAD patients.

Safety profile of proprotein convertase subtilisin/kexin type 9 inhibitors alirocumab and evolocumab: an updated meta-analysis and meta-regression

BACKGROUND

The use of alirocumab and evolocumab is generally safe and well-tolerated. However, concerns remain about their long-term safety, especially with regard to new-onset or worsening diabetes mellitus (DM). We aim to assess the safety profile of alirocumab and evolocumab compared to comparator.

METHODS

Studies were retrieved comparing the safety of PCSK9i vs. comparator (placebo or statin with or without ezetimibe). The primary outcome was adverse events leading to death. Secondary outcomes included serious adverse events, new onset diabetes mellitus (DM), worsening of DM, neurocognitive dysfunction, creatine kinase (CK) elevation, elevation of liver enzymes and local injection site reaction. Factors associated with the treatment effect were determined by meta-regression analysis. Subgroup analyses were done to explore potential treatment effect differences based on PCSK9i type and treatment duration.

RESULTS

We identified 56 studies with 85,123 adults (29.14% females). PCSK9i was not associated with adverse events that lead to death (OR 0.94, 95% CI 0.84 to 1.04, p = 0.22). Between the two PCSK9i, alirocumab decreased adverse events leading to death (OR 0.79, 95% CI, 0.67 to 0.94, p = 0.008). PCSK9i was associated with less serious events compared to the comparator (OR 0.93, 95% CI 0.89 to 0.98, p < 0.001). This reduction was driven mainly by alirocumab (OR 0.89, 95% CI, 0.85 to 0.93, p < 0.001). Evolocumab worsened DM (OR 2.3, 95% CI 1.26 to 4.2, p = 0.041). Subgroup analysis showed worsening of DM in the first 24 weeks of treatment with odds being highest in the first 12 weeks of treatment (<12 weeks: OR 3.82, 95% CI 1.13 to 12.99, p = 0.03; 12-24 weeks OR 2.12, 95% CI 1.20 to 3.73, p = 0.01. On the other hand, therapy >24 weeks reduced the odds of worsening DM (OR 0.89, 95% CI 0.79 to 0.99, p = 0.04). PCSK9i did not increase cognitive dysfunction, (OR 1.02, 95% CI 0.88 to 1.18, p = 0.76), or cause elevations in liver enzyme (OR 0.91, 95% CI 0.81 to 1.03, p = 0.14), or CK (OR 0.82, 95% CI 0.65 to 1.04, p = 0.10). However, PCSK9i was associated with local injection site reaction (OR 1.54, 95% CI 1.37 to 1.73, p < 0.01).

CONCLUSION

Alirocumab decreased adverse events leading to death. Alirocumab and Evolocumab both decreased serious adverse events. PCSK9i did not increase new onset DM however evolocumab worsened DM in the first 24 weeks of treatment. PCSK9i did not increase neurologic dysfunction, and did not elevate liver enzymes and CK, however it was associated with local injection site reaction.

Dysfunctional endocannabinoid CB1 receptor expression and signaling contribute to skeletal muscle cell toxicity induced by simvastatin

Statins are the most prescribed lipid-lowering agents worldwide. Their use is generally safe, although muscular toxicity occurs in about 1 in 10.000 patients. In this study, we explored the role of the endocannabinoid system (ECS) during muscle toxicity induced by simvastatin. In murine C2C12 myoblasts exposed to simvastatin, levels of the endocannabinoids AEA and 2-AG as well the expression of specific miRNAs (in particular miR-152) targeting the endocannabinoid CB1 gene were increased in a time-dependent manner. Rimonabant, a selective CB1 antagonist, exacerbated simvastatin-induced toxicity in myoblasts, while only a weak opposite effect was observed with ACEA and GAT211, selective orthosteric and allosteric agonists of CB1 receptor, respectively. In antagomiR152-transfected myoblasts, simvastatin toxicity was in part prevented together with the functional rescue of CB1. Further analyses revealed that simvastatin in C2C12 cells also suppresses PKC and ERK signaling pathways, which are instead activated downstream of CB1 receptor stimulation, thus adding more insight into the mechanism causing CB1 functional inactivation. Importantly, simvastatin induced similar alterations in skeletal muscles of C57BL/6 J mice and primary human myoblasts. In sum, we identified the dysregulated expression of the endocannabinoid CB1 receptor as well as the impairment of its downstream signaling pathways as a novel pathological mechanism involved in statin-induced myopathy.

Current Insights on Dyslipidaemia Management for Prevention of Atherosclerotic Cardiovascular Disease: A Malaysian Perspective

Dyslipidaemia is highly prevalent in the Malaysian population and is one of the main risk factors for atherosclerotic cardiovascular disease (ASCVD). Low-density lipoprotein cholesterol (LDL-C) is recognised as the primary target of lipid-lowering therapy to reduce the disease burden of ASCVD. Framingham General CV Risk Score has been validated in the Malaysian population for CV risk assessment. The Clinical Practice Guidelines (CPG) on the management of dyslipidaemia were last updated in 2017. Since its publication, several newer randomised clinical trials have been conducted with their results published in research articles and compared in meta-analysis. This underscores a need to update the previous guidelines to ensure good quality care and treatment for the patients. This review summarises the benefits of achieving LDL-C levels lower than the currently recommended target of < 1.8mmol/L without any safety concerns. In most high and very high-risk individuals, statins are the first line of therapy for dyslipidaemia management. However, certain high-risk individuals are not able to achieve the LDL-C goal as recommended in the guideline even with high-intensity statin therapy. In such individuals, lower LDL-C levels can be achieved by combining the statins with non-statin agents such as ezetimibe and PCSK9 inhibitors. Emerging non-statin lipid-lowering therapies and challenges in dyslipidaemia management are discussed in this article. The review also summarises the recent updates on local and international guidelines for dyslipidaemia management.

An Updated Meta-Analysis for Safety Evaluation of Alirocumab and Evolocumab as PCSK9 Inhibitors

Background

Alirocumab and evolocumab, as protein convertase subtilisin kexin type 9 (PCSK9) inhibitors, have been reported to reduce cardiovascular risk. This meta-analysis is aimed at updating the safety data of PCSK9 inhibitors.

Methods

We assessed the relative risk for all treatment-related adverse events, serious adverse events, diabetes-related adverse events, and neurocognitive and neurologic adverse events with PCSK9 inhibitors compared to controls (placebo or ezetimibe). In addition, we conducted a meta-analysis to quantitatively integrate and estimate the adverse event rates in long-term studies.

Results

There were no significant differences between PCSK9 inhibitors and controls in the relative risk analysis. In a subgroup analysis of each PCSK9 inhibitor, alirocumab treatment significantly reduced the risk of serious adverse events compared to control treatment (risk ratio (RR) = 0.937; 95% confidence interval (CI), 0.896-0.980), but no significant difference was observed with evolocumab treatment (RR = 1.003; 95% CI, 0.963-1.054). Moreover, alirocumab treatment afforded a significant reduction in the risk of diabetes-related adverse events compared to control treatment (RR = 0.9137; 95% CI, 0.845-0.987). The overall incidence (event rate) of long-term adverse events was 75.1% (95% CI, 71.2%-78.7%), and the incidence of serious long-term event rate was 16.2% (95% CI, 11.6%-22.3%).

Conclusions

We suggest that alirocumab and evolocumab are generally safe and well tolerated and that their addition to background lipid-lowering therapy is not associated with an increased risk of adverse events or toxicity.

Effects of PCSK9 Inhibition on Coronary Atherosclerosis Regression of Nontarget Lesions after Primary Percutaneous Coronary Intervention in Acute Coronary Syndrome Patients

Aims

To evaluate the regression of coronary atherosclerosis with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition in acute coronary syndrome (ACS) patients following primary percutaneous coronary intervention (PPCI). Methods and Result. We examined 40 nontarget lesions in 17 ACS patients who underwent PPCI and were treated with PCSK9 inhibitors. At 1 year, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and atherogenic index (AI) decreased significantly by 2.5 mmol/L, 2.01 mmol/L, and 1.86, respectively. On quantitative coronary angiography, treatment with PCSK9 inhibitors reduced significantly the atherosclerotic area stenosis in nontarget lesions (61.18 ± 14.55 at baseline vs. 52.85 ± 15.51 at 1 year, P < 0.001).

Conclusions

After 1 year of PCSK9 inhibition treatment for ACS patients, the area stenosis of non-TLR was considerably reduced.

Real-world safety of PCSK9 inhibitors: A pharmacovigilance study based on spontaneous reports in FAERS

Objective: We aimed to evaluate alirocumab- and evolocumab-related adverse events (AEs) in real-world compared with all other drugs, overall and by gender and age subgroups; we also aimed to compare their risks of cognitive impairment, musculoskeletal disorders and diabetes with various statins and ezetimibe. Methods: We retrospectively extracted AE reports from the FDA Adverse Event Reporting System (FAERS) database during July 2015-June 2021. Disproportionality analyses were performed using reporting odds ratios (RORs) to detect AE signals of alirocumab and evolocumab in the overall population and in different age and gender subgroups, respectively. Results: Compared with all other drugs, both alirocumab and evolocumab had a significant signal in "musculoskeletal and connective tissue disorders" (ROR₁ = 2.626, 95% CI 2.552-2.702; ROR2 = 2.575, 95% CI 2.538-2.613). The highest ROR value of 2.311 (95% CI 2.272-2.351) was for "injury, poisoning and procedural complications" and was found in patients aged ≥65 years on evolocumab. The most frequent AEs were "general disorders and administration site conditions" and "musculoskeletal and connective tissue disorders" for all subpopulations. At the preferred term level, the most frequent AE signal was myalgia for alirocumab and injection site pain for evolocumab, overall and by subgroups. Compared with statins/ezetimibe, PCSK9 inhibitors exhibited lower ROR values for adverse events associated with SOC "nervous system disorders", "psychiatric disorders" and "metabolism and nutrition disorders" (all RORs < 1), but mixed results for musculoskeletal disorders. Compared with all other drugs, undocumented AEs, such as acute cardiac event (ROR = 30.0, 95% CI 9.4-95.3) and xanthoma (ROR = 9.3, 95% CI 3.4-25.5), were also reported. Conclusion: Real-world evidence showed that PCSK9 inhibitors were associated with an increased risk of musculoskeletal and connective tissue disorders and general disorders and administration site conditions, overall and by subgroups. Muscle toxicity, injection site reactions, and influenza-like illness were significant AE signals. Compared with various statins and ezetimibe, PCSK9 inhibitors have shown a favorable safety profile in muscle-related events, cognitive impairment and diabetes. Some undocumented AE signals were also reported. Due to the limitations of spontaneous reporting databases, further studies are still needed to establish causality and validate our results.

Current Options and Future Perspectives in the Treatment of Dyslipidemia

Low-density lipoprotein cholesterol (LDL-C) plays a crucial role in the development of atherosclerosis. Statin therapy is the standard treatment for lowering LDL-C in primary and secondary prevention. However, some patients do not reach optimal LDL-C target levels or do not tolerate statins, especially when taking high doses long-term. Combining statins with different therapeutic approaches and testing other new drugs is the future key to reducing the burden of cardiovascular disease (CVD). Recently, several new cholesterol-lowering drugs have been developed and approved; others are promising results, enriching the pharmacological armamentarium beyond statins. Triglycerides also play an important role in the development of CVD; new therapeutic approaches are also very promising for their treatment. Familial hypercholesterolemia (FH) can lead to CVD early in life. These patients respond poorly to conventional therapies. Recently, however, new and promising pharmacological strategies have become available. This narrative review provides an overview of the new drugs for the treatment of dyslipidemia, their current status, ongoing clinical or preclinical trials, and their prospects. We also discuss the new alternative therapies for the treatment of dyslipidemia and their relevance to practice.

Angiopoietin-Like Protein 3 (ANGPTL3) Inhibitors in the Management of Refractory Hypercholesterolemia

Cardiovascular disease (CVD) is the most common cause of death in a global scale and significantly depends on the elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and the subsequent formation of atherosclerotic plaques. While physicians have several LDL-C-lowering agents with diverse mechanisms of action, including statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and inclisiran, angiopoietin-like protein 3 (ANGPTL3) inhibitors have recently emerged as a powerful addition in the armamentarium of lipid-lowering strategies, especially for patients with refractory hypercholesterolemia, as in the case of patients with homozygous familial hypercholesterolemia (HoFH). ANGPTL3 protein is a glycoprotein secreted by liver cells that is implicated in the metabolism of lipids along with other ANGPTL proteins. These proteins inhibit lipoprotein lipase (LPL) and endothelial lipase (EL) in tissues. Loss-of-function mutations affecting the gene encoding ANGPTL3 are linked with lower total cholesterol, LDL-C, and triglyceride (TG) levels. Evinacumab is a monoclonal antibody that targets, binds to, and pharmacologically inhibits ANGPTL3, which was recently approved by the United States Food and Drug Administration (FDA) as a complementary agent to other LDL-C lowering regimens for patients aged 12 or older with HoFH, based on clinical trial evidence that confirmed its safety and efficacy in those patients. Antisense oligonucleotides (ASOs) also represent an interesting class of agents that target and inhibit the mRNA derived from the transcription of ANGPTL3 gene. This review aims to present and discuss the current clinical and scientific data pertaining to the role of ANGPTL3 inhibitors, a novel lipid-modifying class of agents capable of reducing LDL-C levels via a mechanism independent of LDL receptors.

Antitumor activity and molecular mechanism of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a member of the proprotein convertase family of proteins that activate other proteins in cells. Functionally, PCSK9 binds to the receptor of low-density lipoprotein particles (LDL) to regulate cholesterol metabolism and lipoprotein homeostasis in human body. PCSK9 inhibition is a novel pharmacological strategy to control hypercholesterolemia and cardiovascular diseases. Recently accumulating evidence realizes that PCSK9 possesses other roles in cells, such as regulation of tissue inflammatory response, intratumoral immune cell infiltration, and tumor progression. This review discussed the advancement of PCSK9 research on its role and underlying mechanisms in tumor development and progression. For example, PCSK9 inhibition could attenuate progression of breast cancer, glioma, colon tumor, hepatocellular cancer, prostate cancer, and lung adenocarcinoma and promote apoptosis of glioma, prostate cancer, and hepatocellular cancer cells. PCSK9 deficiency could reduce liver metastasis of B16F1 melanoma cells by lowering the circulating cholesterol levels. PCSK9 gene knockdown substantially attenuated mouse tumor growth in vivo by activation of cytotoxic T cells, although PCSK9 knockdown had no effect on morphology and growth rate of different mouse cancer cell lines in vitro. PCSK9 inhibition thus can be used to control human cancers. Future preclinical and clinical studies are warranted to define anti-tumor activity of PCSK9 inhibition.

Dyslipidemia in Renal Transplant Recipients

Dyslipidemia is a frequent complication after kidney transplantation (KT) and is an important risk factor for cardiovascular disease (CVD). Renal transplant recipients (RTRs) are considered at high, or very high, risk of CVD, which is a leading cause of death in this patient group. Despite many factors of post-transplant dyslipidemia, the immunosuppressive treatment has the biggest influence on a lipid profile. There are no strict dyslipidemia treatment guidelines for RTRs, but the ones proposing an individual approach regarding CVD risk seem most suitable. Proper diet and physical activity are the main general measures to manage dyslipidemia and should be introduced initially in every patient after KT. In the case of an insufficient correction of lipemia, statins are the basis for hypolipidemic treatment. Statins should be introduced with caution to avoid serious side-effects (e.g., myopathy) or drug-drug interactions, especially with immunosuppressants. To lower the incidence of adverse effects, and improve medication adherence, ezetimibe in combination with statins is recommended. Fibrates and bile sequestrants are not recommended due to their side-effects and variable efficacy. However, several new lipid-lowering drugs like Proprotein convertase subtilisin/Kexin type9 (PCSK9) inhibitors may have promising effects in RTRs, but further research assessing efficacy and safety is yet to be carried out.

Efficacy and Safety of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors as Adjuvant Treatments for Patients with Hypercholesterolemia Treated with Statin: A Systematic Review and Network Meta-analysis

Background: The proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are potent LDL-C lowering agents. However, few head-to-head studies evaluated the efficacy on the lowering in other atherogenic apolipoproteins and safety of PCSK9 inhibitors at different dosages as an add-on statins therapy in hypercholesterolemia patients.

Methods: This study is a systematic review and network meta-analysis of randomized control trials to compare the efficacy of lipid reduction and adverse events of PCSK9 inhibitors in statin-treated hypercholesterolemia patients. PubMed, EMBASE, and Cochrane Library databases were searched till April 20, 2021, for randomized controlled trials. Random-effect network meta-analyses were undertaken to compare the differences in the percent reduction in low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (ApoB), and lipoprotein (a) [Lp(a)] levels and the risk of AEs among different PCSK9 inhibitors.

Results: A total of 22 articles with 42,786 patients were included. The lipid reductions in LDL-C, ApoB, and Lp(a) with add-on PCSK9 inhibitors vs. placebo in statin-treated patients across all trials were 50–63%, 43–52%, and 23–31%, respectively. Evolocumab 140 mg Q2W was ranked the best among all treatment strategies for lowering LDL-C, ApoB, and Lp(a) levels, and the treatment difference was 68.05% (95% confidence interval (CI), 62.43% to 73.67) in LDL-C reduction, 54.95% (95% CI, 49.55% to 60.35%) in ApoB reduction, and 34.25% (95% CI, 27.59% to 40.91%) in Lp(a) reduction compared with the placebo. No significant risk difference of adverse events between PCSK9 inhibitors and placebo was found.

Conclusion: PCSK9 inhibitors showed a significant effect on the reduction in LDL-C, ApoB, and Lp(a) levels in statin-treated patients. Evolocumab 140 mg Q2W showed significantly larger degrees of LDL-C, ApoB, and Lp(a) reduction.

New and emerging lipid-modifying drugs to lower LDL cholesterol

Cardiovascular disease (CVD) represents the leading cause of death worldwide. The role of low-density lipoprotein-cholesterol (LDL-C) in the pathophysiology of atherosclerosis and CVD has been well recognized. Statins are the standard of care for the management of hypercholesterolaemia, and their effectiveness in lowering LDL-C and reducing CVD risk in both primary and secondary prevention has been well established. However, several patients fail to attain optimal LDL-C goals or are intolerant to statins, especially at high doses. PCSK9 inhibitors, bempedoic acid, inclisiran, ANGPTL3 inhibitors, PPARβ/δ agonists and LXR agonists are novel or upcoming LDL-C-lowering agents that have shown promising beneficial results. This review aims to present and discuss the current clinical and scientific data pertaining to the new and emerging lipid-modifying LDL-C-lowering drugs.

PCSK9 as a new player in cancer: New opportunity or red herring?

Initially described as a factor involved in liver regeneration and neuronal differentiation, proprotein convertase subtilisin/kexin type 9 (PCSK9) has become one of the key regulators of low-density lipoprotein cholesterol. Besides that, a number of studies have suggested PCSK9 may play a role in cancer biology. This is particularly true for gastroenteric (gastric and liver cancers) and lung cancers, where higher PCSK9 levels were associated with the increased ability of the tumor to develop and give metastasis as well as with reduced overall survival. Accordingly, monoclonal antibodies blocking PCSK9 were recently shown to synergize with immunotherapy in different types of cancers to achieve tumor growth suppression through an increased intratumoral infiltration of cytotoxic T cells. Anti-PCSK9 vaccines have been tested in animal models with encouraging results only in colon carcinoma. As most of this evidence is based on pre-clinical studies, this has led to some controversies and inconsistencies, thus suggesting that additional research is needed to clarify the topic. Finally, modulation of intracellular PCSK9 levels by silencing RNA (siRNA) may help understand the physiological and pathological mechanisms of PCSK9.

Prevalence of atherosclerotic cardiovascular disease and subsequent major adverse cardiovascular events in Alberta, Canada: A real-world evidence study

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of morbidity and mortality worldwide. Data from Canadian populations regarding the burden of ASCVD are limited. Therefore, we describe the 5-year period prevalence of ASCVD and subsequent major adverse cardiovascular event (MACE) outcomes among patients with ASCVD in Alberta, Canada.

METHODS

A retrospective, observational study was conducted by linking provincial health services data, vital statistics, and pharmaceutical dispenses data. Five-year period prevalence of clinical ASCVD was captured between 2011 and 2016, and a cohort of adult patients with an initial clinical ASCVD event were identified between 2012 and 2016. One-year incidence rates (IRs) of subsequent MACE outcomes were calculated as composite and individual measures. A subgroup of patients with acute myocardial infarction (AMI) as their index event was examined.

RESULTS

There were 198 573 patients (mean [standard deviation] age: 63.9 [15.6] years; 56.6% males) identified with clinical ASCVD between 2012 and 2016. Overall, the 5-year period prevalence of ASCVD in Alberta was 89.9 per 1000 persons and the 1-year IR for a primary MACE outcome was 6.15 (95% confidence interval [CI]: 6.03-6.26) per 100 person-years. Among the ASCVD cohort, 9465 had an AMI as their index event and the IR for a primary MACE outcome was 14.30 (95% CI: 13.45-15.20) per 100 person-years.

CONCLUSIONS

This study found that the prevalence of ASCVD and the rate of subsequent MACE outcomes 1 year following the initial ASCVD event are substantial, particularly among patients with an AMI. Secondary prevention strategies aimed at lowering this risk are needed for patients with ASCVD.

A safety and clinical efficacy analysis of PCSK9 monoclonal antibodies in patients with markedly elevated creatine phosphokinase levels

INTRODUCTION

PCSK9 inhibitors (PCSK9i) are often used in statin-intolerant patients, aiming to reduce low-density lipoprotein cholesterol (LDL-C). Along with the growing experience with their use, there is a lack of evidence regarding the safety, tolerability, and clinical utility of PCSK9i in patients with markedly elevated creatine phosphokinase (CPK) levels.

METHODS

We screened a comprehensive HMO database for patients treated with PCSK9i (Jan 2016-Dec 2019), in whom elevated CPK levels (>1,000 U/L) were documented prior to the initiation of therapy. Treatment plans, adherence, and the levels of CPK and LDL-C were analyzed.

RESULTS

Of the 1,600 patients initiating treatment with PCSK9i, 26 had prior CPK values >1,000 U/L [median (IQR): 3,687 (1,876-8,344) U/L]. All 26 patients were previously treated with statins, which presumably resulted in adverse effects (myalgia in 24, and rhabdomyolysis in 5 patients) therefore mandating their discontinuation. Concomitant secondary factors for CPK elevation were present in 11 patients, and included renal failure, rheumatoid disorders, hypothyroidism, intensive exercise, proteinuria and genetic muscular disease. Of the 26 patients treated with PCSK9i, alirocumab was administered to 12 patients, and evolocumab to 14. Following the initiation of treatment with either drug, 24 patients (92%) demonstrated a reduction in CPK of >50%, and in 12 (46%) CPK levels have returned to normal values. With regard to treatment goals, 17 patients (65%) have achieved an LDL-C level of <70 mg/dL, and 12 (46%) have reached a level of <55 mg/dL. No serious adverse reactions were documented, and only 2 patients discontinued the treatment (not due to muscle symptoms or CPK elevation).

CONCLUSIONS

PCSK9i constitute a safe, tolerable, and effective treatment for hyperlipidemia in patients with markedly elevated CPK. While statin intolerance is a major cause for CPK elevation, concomitant etiologies for increased CPK values were rather common.

The role of PCSK9 in infectious diseases

BACKGROUND

In recent years, many aspects of the physiological role of PCSK9 have been elucidated, particularly regarding its role in lipid metabolism, cardiovascular risk, and its role in innate immunity. Increasing evidence is available about the involvement of PCSK9 in the pathogenesis of viral infections, mainly HCV, and the regulation of host response to bacterial infections, primarily sepsis and septic shock. Moreover, the action of PCSK9 has been investigated as a crucial step in the pathogenesis of malaria infection and disease severity.

OBJECTIVE

This paper aims to review the available published literature on the role of PCSK9 in a wide array of infectious diseases.

CONCLUSION

Besides the ongoing investigation on PCSK9 inhibition among HIV-infected patients to treat HIV- and ART-related hyperlipidemia, preclinical studies indicate how PCSK9 is involved in reducing the replication of HCV. Interestingly, high plasmatic PCSK9 levels have been described in patients with sepsis. Moreover, a protective role of PCSK9 inhibition has also been proposed against dengue and SARS-CoV-2 viral infections. Finally, a loss of function in the PCSK9-encoding gene has been reported to reduce malaria infection mortality.

Inclisiran-Silencing the Cholesterol, Speaking up the Prognosis

The reduction of circulating low-density lipoprotein-cholesterol (LDL-C) is a primary target in cardiovascular risk reduction due to its well-established benefits in terms of decreased mortality. Despite the use of statin therapy, 10%-20% of high- and very-high-risk patients do not reach their LDL-C targets. There is an urgent need for improved strategies to manage dyslipidemia, especially among patients with homozygous familial hypercholesterolemia, but also in patients with established cardiovascular disease who fail to achieve LDL goals despite combined statin, ezetimibe, and PCSK9 inhibitor (PCSK9i) therapy. Inclisiran is a disruptive, first-in-class small interfering RNA (siRNA)-based therapeutic developed for the treatment of hypercholesterolemia that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9) synthesis, thereby upregulating the number of LDL receptors on the hepatocytes, thus lowering the plasma LDL-C concentration. Inclisiran decreases the LDL-C levels by over 50% with one dose every 6 months, making it a simple and well-tolerated treatment strategy. In this review, we summarize the general information regarding (i) the role of LDL-C in atherosclerotic cardiovascular disease, (ii) data regarding the role of PCSK9 in cholesterol metabolism, (iii) pleiotropic effects of PCSK9, and (iv) the effects of PCSK9 silencing. In addition, we focus on inclisiran, in terms of its (i) mechanism of action, (ii) biological efficacy and safety, (iii) results from the ORION trials, (iv) benefits of its combination with statins, and (v) its potential future role in atherosclerotic cardiovascular disease.