The efficacy advantage of evolocumab (AMG 145) dosed at 140mg every 2weeks versus 420mg every 4weeks in patients with hypercholesterolemia: Evidence from a meta-analysis

The Efficacy of Tafolecimab in Chinese Patients with Hypercholesterolemia: A Systematic Review and Meta-analysis

BACKGROUND

Cardiovascular disease was the leading cause of death worldwide in 2021, with atherosclerotic cardiovascular disease, encompassing hypercholesterolemia, being a major contributing factor. A range of lipid-lowering medications is used for the management of hyperlipidemia, but the use of statins is considered as standard therapy. Unfortunately, some patients do not respond to this therapy, necessitating novel therapeutic approaches. Tafolecimab is a novel proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibody that inhibits the binding of PCSK9 with low-density lipoprotein receptors (LDLRs) and increases LDLR recycling, and thus it indirectly lowers circulating low-density lipoprotein cholesterol (LDL-C) levels by increasing LDL-C uptake. The primary objective of this study is to assess the efficacy of tafolecimab in reducing LDL-C levels.

METHODS

A thorough search was conducted on Medline (PubMed), Cochrane CENTRAL, Scopus, and Google Scholar from inception until December 2023. Review Manager was used for statistical analysis. The random effects model was used to calculate risk ratios (RRs), mean differences (MDs), and 95% confidence intervals (CIs). Heterogeneity was assessed using the Higgins I2 index. The risk of bias was assessed using Cochrane's RoB 2 tool. This review has been registered with PROSPERO (CRD42023471020).

RESULTS

A total of four Chinese studies matched the inclusion criteria and were included in this review. A total of 726 patients were included in this review, out of which 476 patients were males. Out of four, three studies that studied the efficacy of 450 mg tafolecimab every 4 weeks in patients (n = 462) as compared to placebo (n = 224) were included in the meta-analysis. According to the pooled results, tafolecimab caused a significant decrease in LDL-C levels from baseline to week 12 as compared to placebo (MD = - 63.78, 95% CI - 65.88 to - 61.68, p value < 0.00001, I2 = 97%). The pooled results showed that more patients achieved ≥ 50% reductions in LDL-C levels (RR = 52.33, 95% CI 18.51-147.95, p value < 0.00001, I2 = 0%) and LDL-C < 1.8 mmol/L (RR = 17.27, 95% CI 9.59-31.11, p value < 0.00001, I2 = 0%) at week 12 in the tafolecimab group than the placebo group. Additionally, tafolecimab also caused a robust decrease in non-HDL-C, apolipoprotein B, and lipoprotein(a) levels from baseline to week 12 compared to placebo. The overall risk of bias was low, as determined by the RoB 2 tool.

CONCLUSIONS

Tafolecimab showed promising lipid-lowering efficacy and a well-tolerated safety profile. Our findings suggest its potential as an innovative therapeutic option for individuals with hypercholesterolemia; however, significant heterogeneity was observed in some results, making it difficult to come to a firm conclusion. Therefore, large-scale randomized trials are required to confirm our findings, particularly exploring the most effective dosage regimens across varied populations.

REGISTRATION

PROSPERO identifier number CRD42023471020.

A Systematic Review and Meta-Analysis of Therapeutic Efficacy and Safety of Alirocumab and Evolocumab on Familial Hypercholesterolemia

Objectives

The aim of this study was to provide the first study to systematically analyze the efficacy and safety of PCSK9-mAbs in the treatment of familial hypercholesterolemia (FH).

Methods

A computer was used to search the electronic Cochrane Library, PubMed/MEDLINE, and Embase databases for clinical trials using the following search terms: "AMG 145", "evolocumab", "SAR236553/REGN727", "alirocumab", "RG7652", "LY3015014", "RN316/bococizumab", "PCSK9", and "familial hypercholesterolemia" up to November 2020. Study quality was assessed with the Cochrane Collaboration's tool, and publication bias was evaluated by a contour-enhanced funnel plot and the Harbord modification of the Egger test. After obtaining the data, a meta-analysis was performed using R software, version 4.0.3.

Results

A meta-analysis was performed on 7 clinical trials (926 total patients). The results showed that PCSK9-mAbs reduced the LDL-C level by the greatest margin, WMD -49.14%, 95% CI: -55.81 to -42.47%, on FH versus control groups. PCSK9-mAbs also significantly reduced lipoprotein (a) (Lp (a)), total cholesterol (TC), triglycerides (TG), apolipoprotein-B (Apo-B), and non-high-density lipoprotein cholesterol (non-HDL-C) levels and increased HDL-C and apolipoprotein-A1 (Apo-A1) levels of beneficial lipoproteins. Moreover, no significant difference was found between PCSK9-mAbs treatment and placebo in common adverse events, serious events, and laboratory adverse events.

Conclusion

PCSK9-mAbs significantly decreased LDL-C and other lipid levels with satisfactory safety and tolerability in FH treatment.

Three Musketeers for Lowering Cholesterol: Statins, Ezetimibe and Evolocumab

Coronary heart disease (CHD) is closely related to hypercholesterolemia, and lowering serum cholesterol is currently the most important strategy in reducing CHD. In humans, the serum cholesterol level is determined mainly by three metabolic pathways, namely, dietary cholesterol intake, cholesterol synthesis, and cholesterol degradation in vivo. An intervention that targets the key molecules in the three pathways is an important strategy in lowering serum lipids. Statins inhibit 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) to reduce low-density lipoprotein (LDL) by about 20% to 45%. However, up to 15% of patients cannot tolerate the potential side effects of high statin dosages, and several patients also still do not reach their optimal LDL goals after being treated with statins. Ezetimibe inhibits cholesterol absorption by targeting the Niemann-Pick C1-like 1 protein (NPC1L1), which is related to cholesterol absorption in the intestines. Ezetimibe lowers LDL by about 18% when used alone and by an additional 25% when combined with statin therapy. The proprotein convertase subtilisin/kexin type 9 (PCSK9) increases hepatic LDLR degradation, thereby reducing the liver's ability to remove LDL, which can lead to hypercholesterolemia. Evolocumab, which is a PCSK9 monoclonal antibody, can reduce LDL from baseline by 53% to 56%. The three drugs exert lipid-lowering effects by regulating the three key pathways in lipid metabolism. Combining any with the two other drugs on the basis of statin treatment has improved the lipid-lowering effect. Whether the combination of the three musketeers will reduce the side effects of monotherapy and achieve the lipid-lowering effect should be studied further in the future.

PCSK9 promotes tumor growth by inhibiting tumor cell apoptosis in hepatocellular carcinoma

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key enzymes in the process of lipid transport, is involved in the disease progression of various types of tumors. This article is to study the role of PCSK9 in the progression of hepatocellular carcinoma (HCC).

Methods

Immunohistochemistry was used to assess the expression of PCSK9 in tumor specimens from 105 HCC patients who underwent curative resection. Western blotting and quantitative real-time PCR were used to test the protein and mRNA expression levels in HCC cell lines. Cell Counting Kit-8 (CCK-8) and clone formation assays were performed to evaluate the proliferation ability of different kinds of cells in vitro. Flow cytometry was used to analyze cell cycle distribution and apoptosis rate. A xenograft model was established to study the effect of PCSK9 on HCC growth in vivo. TUNEL and immunofluorescence assays were used to detect cell apoptosis.

Results

High expression of PCSK9 in tumor tissues was related to microvascular invasion (p = 0.036) and large tumor size (p = 0.001) in HCC patients. Overall survival and disease-free survival after surgery were poor in patients with high expression of PCSK9 (p = 0.035 and p = 0.007, respectively). In vivo and in vitro experiments showed that PCSK9 promoted the growth of HCC by inhibiting cell apoptosis. A mechanistic study revealed that PCSK9 increases FASN expression, thereby inhibiting apoptosis of HCC cells via the Bax/Bcl-2/Caspase9/Caspase3 pathway.

Conclusions

PCSK9 expression level in HCC is an indicator of poor prognosis for patients with HCC. FASN-mediated anti-apoptosis plays an important role in PCSK9-induced HCC progression.

A New Strategy for Rapidly Screening Natural Inhibitors Targeting the PCSK9/LDLR Interaction In Vitro

The interaction between proprotein convertase subtilisin/kexin type 9 (PCSK9) and the low-density lipoprotein receptor (LDLR) is a promising target for the treatment of hyperc-holesterolemia. In this study, a new method based on competitive affinity and tag detection was developed, which aimed to evaluate potent natural inhibitors preventing the interaction of PCSK9/LDLR directly. Herein, natural compounds with efficacy in the treatment of hypercholesterolemia were chosen to investigate their inhibitory activities on the PCSK9/LDLR interaction. Two of them, polydatin (1) and tetrahydroxydiphenylethylene-2-O-glucoside (2), were identified as potential inhibitors for the PCSK9/LDLR interaction and were proven to prevent PCSK9-mediated LDLR degradation in HepG2 cells. The results suggested that this strategy could be applied for evaluating potential bioactive compounds inhibiting the interaction of PCSK9/LDLR and this strategy could accelerate the discovery of new drug candidates for the treatment of PCSK9-mediated hypercholesterolemia.

Discovery of Flavonoids from Scutellaria baicalensis with Inhibitory Activity Against PCSK 9 Expression: Isolation, Synthesis and Their Biological Evaluation

Nine flavonoids were isolated and identified from a chloroform-soluble fraction of the roots of Scutellaria baicalensis through a bioactivity-guided fractionation using a proprotein convertase subtilisin/kexin type 9 (PCSK9) monitoring assay in HepG2 cells. All structures were established by interpreting the corresponding spectroscopic data and comparing measured values from those in the literature. All compounds were assessed for their ability to inhibit PCSK9 mRNA expression; compounds 1 (3,7,2'-trihydroxy-5-methoxy-flavanone) and 4 (skullcapflavone II) were found to suppress PCSK9 mRNA via SREBP-1. Furthermore, compound 1 was found to increase low-density lipoprotein receptor protein expression. Also, synthesis of compound 1 as a racemic mixture form (1a) was completed for the first time. Natural compound 1 and synthetic racemic 1a were evaluated for their inhibitory activities against PCSK9 mRNA expression and the results confirmed the stereochemistry of 1 was important.