Safety of Proprotein Convertase Subtilisin/Kexin Type 9 Monoclonal Antibodies in Regard to Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Controlled Trials

How safe are proprotein convertase subtilisinekexin type 9 inhibitors in diabetes?

PURPOSE OF REVIEW

To examine the safety of proprotein convertase subtilisinekexin type 9 (PCSK9) inhibitors in patients with diabetes, specifically focusing on their impact on glucose metabolism.

RECENT FINDINGS

Patients with diabetes often require intensified lipid-lowering therapy. PCSK9 inhibitors can reduce low-density lipoprotein cholesterol (LDL-C) concentrations by approximately 60%, and significantly reduce cardiovascular risk when added to statin therapy. Some studies have suggested an association between low LDL-C levels and an increased risk of new-onset diabetes, and genetics has almost consistently shown an increased glucose concentration and risk of diabetes. Most clinical trials have not demonstrated a deterioration in glycaemic control in patients with diabetes after the use of PCSK9 inhibitors, and they do not lead to other significant treatment-emergent adverse events.

SUMMARY

Although the majority of patients with diabetes are undergoing background statin therapy, which may mask potential adverse effects of PCSK9 inhibitors on glycaemic control, current data suggest that the benefits outweigh the risks for diabetic patients using PCSK9 inhibitors. Considering the different nature of genetic studies and of clinical trials, close monitoring of glucose parameters is necessary, especially in individuals with prediabetes.

Impact of PCSK9 inhibitors in glycaemic control and new-onset diabetes

BACKGROUND

The diabetogenic effect of statins has been well established by clinical trials, Mendelian randomisation studies and meta-analyses. According to large clinical trials, PCSK9 inhibitors (PCSK9i) have no deleterious impact on glucose metabolism. However, few real-life studies have yet evaluated the long-term effects of these drugs on glucose homeostasis and their impact on new-onset diabetes (NODM).

METHODS

We studied 218 patients treated with either alirocumab or evolocumab (70% with familial hypercholesterolemia) for at least three years (PCSK9iG). We studied the NODM rate in the nondiabetic group at baseline (168) and overall glucose metabolism control in the whole group. Incidental DM was compared with two groups. The first was a propensity score matching (PSM)-selected group (n = 168) from the database of patients attending the Reus lipid unit (Metbank, n = 745) who were not on PCSK9i (PSMG). The second was a subgroup with a similar age range (n = 563) of the Di@bet.es study (Spanish prospective study on diabetes development n = 5072) (D@G). The incidence was reported as the percentage of NODM cases per year.

RESULTS

The fasting glucose (FG) level of the subjects with normoglycaemia at baseline increased from 91 (86-95.5) to 93 (87-101) mg/dL (p = 0.014). There were 14 NODM cases in the PCSK9i group (2.6%/y), all among people with prediabetes at baseline. The incidence of NODM in PSMG and D@G was 1.8%/y (p = 0.69 compared with the PCSK9iG). The incidence among the subjects with prediabetes was 5.1%/y in the PCSK9iG, 4.8%/y in the PSMG and 3.9%/y in the D@G (p = 0.922 and p = 0.682, respectively). In the multivariate analysis, only the FG level was associated with the development of NODM in the PCSK9iG (OR 1.1; 95% CI: 1.0-1.3; p = 0.027). Neither FG nor A1c levels changed significantly in patients with DM at baseline.

CONCLUSION

A nonsignificant increase in NODM occurred in the PCSK9iG, particularly in patients with prediabetes, compared with the PSMG and D@G groups. Baseline FG levels were the main variable associated with the development of DM. In the subjects who had DM at baseline, glucose control did not change. The impact of PCSK9i on glucose metabolism should not be of concern when prescribing these therapies.

Assessing the Impact of PCSK9 and HMGCR Inhibition on Liver Function: Drug-Target Mendelian Randomization Analyses in Four Ancestries

BACKGROUND & AIMS

Observational studies have linked lipid-lowering drug targets pro-protein convertase subtilisin/kexin 9 (PCSK9) and HMG-CoA reductase (HMGCR) with adverse liver outcomes; however, liver disease incidence varies across diverse populations, and the long-term hepatic impact of these lipid-lowering drugs among non-white Europeans remains largely unknown.

METHODS

We use single nucleotide polymorphisms (SNPs) in PCSK9 and HMGCR loci from genome-wide association study data of low-density lipoprotein cholesterol in 4 populations (East Asian [EAS], South Asian [SAS], African [AFR], and European [EUR]) to perform drug-target Mendelian randomization investigating relationships between PCSK9 and HMGCR inhibition and alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), and bilirubin.

RESULTS

Analyses of PCSK9 instruments, including functional variants R46L and E670G, failed to find evidence for relationships of low-density lipoprotein cholesterol lowering via PCSK9 variants and adverse effects on ALT, AST, GGT, or ALP among the cohorts. PCSK9 inhibition was associated with increased direct bilirubin levels in EUR (β = 0.089; P value = 5.69 × 10-6) and, nominally, in AFR (β = 0.181; P value = .044). HMGCR inhibition was associated with reduced AST in SAS (β = -0.705; P value = .005) and, nominally, reduced AST in EAS (β = -0.096; P value = .03), reduced ALP in EUR (β = -2.078; P value = .014), and increased direct bilirubin in EUR (β = 0.071; P value = .032). Sensitivity analyses using genetic instruments derived from circulating PCSK9 protein levels, tissue-specific PCSK9 expression, and HMGCR expression were in alignment, strengthening causal inference.

CONCLUSIONS

We did not find ALT, AST, GGT, or ALP associated with genetically proxied PCSK9 and HMGCR inhibition across ancestries. We identified possible relationships in several ancestries between PCSK9 and increased direct and total bilirubin and between HMGCR and reduced AST. These findings support long-term safety profiles and low hepatotoxic risk of PCSK9 and HMGCR inhibition in diverse populations.

The association between circulatory, local pancreatic PCSK9 and type 2 diabetes mellitus: The effects of antidiabetic drugs on PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a potent modulator of cholesterol metabolism and plays a crucial role in the normal functioning of pancreatic islets and the progression of diabetes. Islet autocrine PCSK9 deficiency can lead to the enrichment of low-density lipoprotein (LDL) receptor (LDLR) and excessive LDL cholesterol (LDL-C) uptake, subsequently impairing the insulin secretion in β-cells. Circulatory PCSK9 levels are primarily attributed to hepatocyte secretion. Notably, anti-PCSK9 strategies proposed for individuals with hypercholesterolemia chiefly target liver-derived PCSK9; however, these anti-PCSK9 strategies have been associated with the risk of new-onset diabetes mellitus (NODM). In the current review, we highlight a new direction in PCSK9 inhibition therapy strategies: screening candidates for anti-PCSK9 from the drugs used in type 2 diabetes mellitus (T2DM) treatment. We explored the association between circulating, local pancreatic PCSK9 and T2DM, as well as the relationship between PCSK9 monoclonal antibodies and NODM. We discussed the emergence of artificial and natural drugs in recent years, exhibiting dual benefits of antidiabetic activity and PCSK9 reduction, confirming that the diverse effects of these drugs may potentially impact the progression of diabetes and associated disorders, thereby introducing novel avenues and methodologies to enhance disease prognosis.

Advanced progress of the relationship between PCSK9 monoclonal antibodies and hyperglycemic adverse events

Purpose of Review

Long-term use of statins had been confirmed to cause an increase in hyperglycemic adverse events (HAEs), whose mechanism has been well understood. Proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies (PCSK9-mAbs), a kind of new lipid-lowering drug, can effectively reduce plasma low-density lipoprotein cholesterol levels in patients with CHD and have been widely used. However, animal experiments, Mendelian randomization studies, clinical researches and Meta-analyses which focused on the relationship between PCSK9-mAbs and HAEs had reached different conclusions, which has attracted great attention from clinicians.

Recent Findings

The newest FOURIER-OLE randomized controlled trial followed PCSK9-mAbs users for over 8 years, whose results suggested that long-term use of PCSK9-mAbs did not increase the incidence of HAEs. Newest Meta-analyses also indicated that there was no relationship between PCSK9-mAbs and NOD. Meanwhile, genetic polymorphisms and variants related to PCSK9 might have effects on HAEs.

Conclusion

According to the results of current studies, there is no significant relationship between PCSK9-mAbs and HAEs. However, longer-term follow-up studies are still needed to confirm it. Although PCSK9 genetic polymorphisms and variants may affect the possible occurrence of HAEs, there is no need to perform relevant genetic testing before applying PCSK9-mAbs.

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.

PCSK9 inhibitors for acute coronary syndrome: the era of early implementation

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a new cholesterol-lowering strategy, can decrease low-density lipoprotein cholesterol (LDL-C) levels by inhibiting PCSK9 and reducing the degradation of LDL receptors; thus, they are impacting the management of dyslipidemia to the prevention of cardiovascular events. Recent guidelines recommend PCSK9 inhibitors for patients who fail to achieve target lipids after ezetimibe/statin therapy. As PCSK9 inhibitors have been demonstrated to significantly and safely reduce LDL-C, discussions have begun to explore its optimal timing in coronary artery disease, especially in subjects with acute coronary syndrome (ACS). Also, their additional benefits, such as anti-inflammatory effects, plaque regression effects, and cardiovascular event prevention, have become the focus of recent research. Several studies, including EPIC-STEMI, suggest the lipid-lowering effects of early PCSK9 inhibitors in ACS patients, while some studies such as PACMAN-AMI suggest that early PCSK9 inhibitors can decelerate plaque progression and reduce short-term risks of cardiovascular events. Thus, PCSK9 inhibitors are entering the era of early implementation. In this review, we are committed to summarizing the multidimensional benefits of early implementation of PCSK9 inhibitors in ACS.

Diabetes and Familial Hypercholesterolemia: Interplay between Lipid and Glucose Metabolism

Familial hypercholesterolemia (FH) is a genetic disease characterized by high low-density lipoprotein (LDL) cholesterol (LDL-c) concentrations that increase cardiovascular risk and cause premature death. The most frequent cause of the disease is a mutation in the LDL receptor (LDLR) gene. Diabetes is also associated with an increased risk of cardiovascular disease and mortality. People with FH seem to be protected from developing diabetes, whereas cholesterol-lowering treatments such as statins are associated with an increased risk of the disease. One of the hypotheses to explain this is based on the toxicity of LDL particles on insulin-secreting pancreatic β-cells, and their uptake by the latter, mediated by the LDLR. A healthy lifestyle and a relatively low body mass index in people with FH have also been proposed as explanations. Its association with superimposed diabetes modifies the phenotype of FH, both regarding the lipid profile and cardiovascular risk. However, findings regarding the association and interplay between these two diseases are conflicting. The present review summarizes the existing evidence and discusses knowledge gaps on the matter.

The Biological Relevance of PCSK9: When Less Is Better…

Proprotein Convertase Subtilisin/Kexin-type 9 (PCSK9) is a circulating negative regulator of hepatic low-density lipoprotein receptor (LDLR) which clears cholesterol from blood. Gain-of-function genetic mutations which amplify PCSK9 activity have been found to cause potentially lethal familial hypercholesterolemia. Inversely, reduction of its activity through loss-of-function genetics or with pharmaceuticals was shown to increase hepatic LDLR, to lower blood cholesterol, and to protect against cardiovascular diseases. New epidemiological and experimental evidence suggests that this reduction could also attenuate inflammation, reinforce cancer immunity, provide resistance to infections, and protect against liver pathologies. In this review, we question the relevance of this protein under normal physiology. We propose that PCSK9 is an important, but non-essential, modulator of cholesterol metabolism and immunity, and that its pathogenicity results from its chronic overexpression.

PCSK9 Inhibitors and Neurocognitive Adverse Drug Reactions: Analysis of Individual Case Safety Reports from the Eudravigilance Database

Introduction

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9Is) were associated with a risk of neurocognitive adverse drug reactions (ADRs).

Objective

We aimed to investigate the occurrence of neuropsychiatric ADRs related to PCSK9Is.

Methods

We analyzed Individual Case Safety Reports (ICSRs) sent through the European pharmacovigilance database that reported alirocumab or evolocumab as the suspected drug and at least one neurological or psychiatric ADR. The reporting odds ratio (ROR) was computed to compare the probability of reporting ICSRs with neuropsychiatric ADRs between alirocumab, evolocumab and statins.

Results

Overall, 2041 ICSRs with alirocumab and/or evolocumab as the suspected drug described the occurrence of neuropsychiatric ADRs. The most reported preferred terms for both drugs were headache, insomnia and depression. No difference between alirocumab and evolocumab was observed for the RORs of ICSRs with ADRs belonging to the System Organ Classes (SOCs) ‘Nervous system disorders’ or ‘Psychiatric disorders’ (ROR 1.02, 95% confidence interval 0.91–1.14; and 1.12, 95% CI 0.94–1.34, respectively), while evolocumab and alirocumab had a higher reporting probability of ICSRs with ADRs belonging to the SOC ‘Nervous system disorders’ compared with atorvastatin and fluvastatin. A lower reporting probability was instead found for ICSRs with ADRs belonging to the SOC ‘Psychiatric disorders’ for evolocumab and alirocumab versus simvastatin, pravastatin and rosuvastatin.

Conclusion

Our results demonstrated that 22.7% of all ICSRs reporting alirocumab or evolocumab as suspect drugs described the occurrence of neuropsychiatric ADRs. The ROR showed that evolocumab and alirocumab had a higher reporting probability of neurological ADRs compared with statins. Further data from real-life contexts are needed.

Electronic supplementary material

The online version of this article (10.1007/s40264-020-01021-3) contains supplementary material, which is available to authorized users.

Efficacy and safety of PCSK9 monoclonal antibodies: an evidence-based review and update

Objective

Treatment of dyslipidemia lowers cardiovascular (CV) risk. Although statin use is a cornerstone therapy, many patients are not achieving their risk-specific low-density lipoprotein cholesterol (LDL-C) goals. The proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies have been extensively studied as lipid-lowering therapy (LLT). Herein, we present an updated evidence-based review of the efficacy and safety of PCSK9 monoclonal antibodies in the treatment of familial and non-familial hypercholesterolemia.

Methods

PubMed database was searched to review Phase III studies on PCSK9 monoclonal antibodies. Then, the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform were searched to identify and present the ongoing research.

Results

PCSK9 monoclonal antibodies were investigated for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional LLT. They proved effective and safe in the treatment of familial and non-familial hypercholesterolemia, and in the prevention of adverse CV events.

Conclusions

The use of PCSK9 monoclonal antibodies in the treatment of dyslipidemia is currently recommended to achieve risk-specific LDL-C goal to reduce adverse CV events. Future results of the ongoing research might expand their clinical generalizability to broader patient populations.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors and Ezetimibe on Risk of New-Onset Diabetes: A Systematic Review and Meta-Analysis of Large, Double-Blinded Randomized Controlled Trials

Background:

Previous meta-analyses have shown that statins may cause incident diabetes. This article reviews randomized controlled trials using proprotein convertase subtilisin/kexin 9 inhibitors (PCSK9i) or ezetimibe on the risk of new-onset diabetes.

Methods:

Eight trials involving PCSK9i and 3 trials of ezetimibe were selected for review. PubMed, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov were thoroughly searched for relevant trials. Inclusion criteria included at least 100 patients per treatment arm, follow-up of at least 52 weeks, and at least double-blinded study design. Exclusion criteria included patients with previously diagnosed diabetes, nonrandomized, placebo-controlled, open-label, and crossover trials. The primary outcome was the number of incident diabetes cases. A random effects model was used. Heterogeneity in effect sizes was measured with I 2 parameter and the Q statistic was used to test for excessive between-study heterogeneity.

Results:

A total of 52 214 participants for the PCSK9i and a total of 20 084 for the ezetimibe meta-analyses were included. Participants randomized to PCSK9i did not differ from the control patients in diabetes incidence (risk ratio [RR] = 0.99, P = .87, 95% CI = 0.92-1.07). Participants randomized to ezetimibe did not differ from the control patients in diabetes incidence (RR = 1.05, P = .37, 95% CI = 0.95-1.15).

Discussion:

The use of PCSK9i and ezetimibe does not appear to impact the risk of incident diabetes mellitus when added to guideline-directed medical therapy.

PCSK9 Monoclonal Antibodies: An Overview

PCSK9 monoclonal antibodies are novel lipid-lowering therapy that have been extensively studied in patients with hypercholesterolemia either as monotherapy or as an add-on to other LLTs. PCSK9 monoclonal antibodies have significantly reduced the low-density lipoprotein cholesterol (LDL-C) plasma level resulting in a better LDL-C goal attainment. The commercially available PCSK9 monoclonal antibodies, alirocumab and evolocumab, have demonstrated reductions in major adverse cardiovascular events such as myocardial infarction, stroke, unstable angina, and the need for coronary revascularization but not mortality. PCSK9 monoclonal antibodies have demonstrated a favorable safety profile. The most reported side effects are mild injection site with no causal relationship proven between the inhibition of PCSK9 and neurocognitive or glycemic adverse events. In this overview, the efficacy and safety of PCSK9 monoclonal antibodies in the treatment of primary and familial hypercholesterolemia will be discussed.