Dabigatran etexilate activation is affected by the CES1 genetic polymorphism G143E (rs71647871) and gender

Pharmacogenetic study of CES1 gene and enalapril efficacy

Enalapril is an orally administered angiotensin-converting enzyme inhibitor which is widely prescribed to treat hypertension, chronic kidney disease, and heart failure. It is an ester prodrug that needs to be activated by carboxylesterase 1 (CES1). CES1 is a hepatic hydrolase that in vivo biotransforms enalapril to its active form enalaprilat in order to produce its desired pharmacological impact. Several single nucleotide polymorphisms in CES1 gene are reported to alter the catalytic activity of CES1 enzyme and influence enalapril metabolism. G143E, L40T, G142E, G147C, Y170D, and R171C can completely block the enalapril metabolism. Some polymorphisms like Q169P, E220G, and D269fs do not completely block the CES1 function; however, they reduce the catalytic activity of CES1 enzyme. The prevalence of these polymorphisms is not the same among all populations which necessitate to consider the genetic panel of respective population before prescribing enalapril. These genetic variations are also responsible for interindividual variability of CES1 enzyme activity which ultimately affects the pharmacokinetics and pharmacodynamics of enalapril. The current review summarizes the CES1 polymorphisms which influence the enalapril metabolism and efficacy. The structure of CES1 catalytic domain and important amino acids impacting the catalytic activity of CES1 enzyme are also discussed. This review also highlights the importance of pharmacogenomics in personalized medicine.

Circulating microRNAs and DNA Methylation as Regulators of Direct Oral Anticoagulant Response in Atrial Fibrillation and Key Elements for the Identification of the Mechanism of Action (miR-CRAFT): Study Design and Patient Enrolment

Direct oral anticoagulants (DOACs) are the standard treatment for thromboembolic protection in atrial fibrillation (AF) patients. Epigenetic modifications, such as DNA methylation and microRNAs, have emerged as potential biomarkers of AF. The epigenetics of DOACs is still an understudied field. It is largely unknown whether epigenetic modifications interfere with DOAC response or whether DOAC treatment induces epigenetic modifications. To fill this gap, we started the miR-CRAFT (Circulating microRNAs and DNA methylation as regulators of Direct Oral Anticoagulant Response in Atrial Fibrillation) research study. In miR-CRAFT, we follow, over time, changes in DNA methylation and microRNAs expression in naïve AF patients starting DOAC treatment. The ultimate goal of miR-CRAFT is to identify the molecular pathways epigenetically affected by DOACs, beyond the coagulation cascade, that are potentially mediating DOAC pleiotropic actions and to propose specific microRNAs as novel circulating biomarkers for DOAC therapy monitoring. We herein describe the study design and briefly present the progress in participant enrolment.

Regulation of carboxylesterases and its impact on pharmacokinetics and pharmacodynamics: an up-to-date review

INTRODUCTION

Carboxylesterase 1 (CES1) and carboxylesterase 2 (CES2) are among the most abundant hydrolases in humans, catalyzing the metabolism of numerous clinically important medications, such as methylphenidate and clopidogrel. The large interindividual variability in the expression and activity of CES1 and CES2 affects the pharmacokinetics (PK) and pharmacodynamics (PD) of substrate drugs.

AREAS COVERED

This review provides an up-to-date overview of CES expression and activity regulations and examines their impact on the PK and PD of CES substrate drugs. The literature search was conducted on PubMed from inception to January 2024.

EXPERT OPINION

Current research revealed modest associations of CES genetic polymorphisms with drug exposure and response. Beyond genomic polymorphisms, transcriptional and posttranslational regulations can also significantly affect CES expression and activity and consequently alter PK and PD. Recent advances in plasma biomarkers of drug-metabolizing enzymes encourage the research of plasma protein and metabolite biomarkers for CES1 and CES2, which could lead to the establishment of precision pharmacotherapy regimens for drugs metabolized by CESs. Moreover, our understanding of tissue-specific expression and substrate selectivity of CES1 and CES2 has shed light on improving the design of CES1- and CES2-activated prodrugs.

Role of CES1 and ABCB1 Genetic Polymorphisms on Functional Response to Dabigatran in Patients with Atrial Fibrillation

Background: Dabigatran etexilate is a pro-drug hydrolyzed into dabigatran by carboxylesterases (CES) and is a substrate of the P-Glycoprotein encoded by the adenosine-triphosphate-binding cassette sub-family B member (ABCB)1 genes. We evaluated the functional response to dabigatran according to different CES1 and ABCB1 single-nucleotide polymorphisms (SNPs) in patients with atrial fibrillation (AF). Methods: A total of 100 consecutive patients with AF taking dabigatran were enrolled by two Italian centers. A venous blood sample was drawn for genetic determinations, as well as a measurement of the diluted thrombin time (dTT) and drug plasma concentrations, at the trough and peak. The main objective was the relationship between the dTT values and CES1 rs2244613, CES1 rs8192935 and ABCB1 rs4148738 SNP while on two different dabigatran doses (110 and 150 mg BID). Results: A total of 43 patients were on a 110 mg dabigatran dose and 57 on 150 mg. The DTT values at the trough and at peak were not different among patients with different CES1 rs2244613 and CES1 rs8192935 genotypes, regardless of the dabigatran dose. In patients on 150 mg dabigatran, the dTT values at the trough were 77 (44-111) ng/mL in patients with the ABCB1 rs4148738 heterozygous CT genotype vs. 127 (85-147) ng/mL in the wild-type CC genotype vs. 110 (47-159) ng/mL in the mutant trait TT genotype (p = 0.048). In patients with the ABCB1 rs4148738 CT genotype, OR for having dTT values at a trough below the median was 3.21, 95% CI 1.04-9.88 (p = 0.042). Conclusions: ABCB1 rs4148738 CT heterozygous is associated with the reduced anticoagulant activity of dabigatran at the trough in patients receiving the higher dose regimen.

Identification and comparison of sex-specific serious adverse drug reactions in spontaneous reports and systematically collected reports (ADRED)

AIMS

Adverse drug reactions (ADRs) are known to show sex-specific differences in occurrence and phenotype. The aim of this study was to analyse sex-specific differences in ADR-drug combinations that required hospitalization based on two different datasets.

METHODS

We performed a complementary analysis of (i) spontaneously reported (n = 12 564, female = 51.7%) and (ii) systematically collected ADR reports from a prospective multicentre observational study (ADRED, n = 2355, female = 48.2%) from Germany in the ADR database EudraVigilance (EV). Both datasets were analysed separately concerning the suspected drugs, ADRs and ADR-drug combinations more frequently reported for females or males by calculating reporting odds ratios (ROR) with 95% confidence intervals. ADR-drug combinations more frequently reported for either females or males in EV reports were related to prescription data. Finally, the results from both datasets were discussed with regard to their (dis-)concordance.

RESULTS

In both datasets, some antineoplastic agents and nervous system drugs were found to be reported more often for females than males (RORs ranging from 1.5 [1.1-2.1] for quetiapine in spontaneous reports to 41.3 [13.1-130.0] for trastuzumab in spontaneous reports). ADRs of the respiratory system, and haemorrhages were described predominantly for males in both datasets. In spontaneous reports the ADR-drug combination self-injurious behaviour-quetiapine was more often reported for females without and with consideration of drug prescriptions (ROR: 3.8 [1.3-11.0]). Quetiapine and psychiatric disorders (superordinate level) was exclusively reported for females in ADRED reports.

CONCLUSIONS

Our results can contribute to raise awareness and further knowledge regarding sex-specific ADRs. The findings require further in-depth investigation.

Simultaneously Predicting the Pharmacokinetics of CES1-Metabolized Drugs and Their Metabolites Using Physiologically Based Pharmacokinetic Model in Cirrhosis Subjects

Hepatic carboxylesterase 1 (CES1) metabolizes numerous prodrugs into active ingredients or direct-acting drugs into inactive metabolites. We aimed to develop a semi-physiologically based pharmacokinetic (semi-PBPK) model to simultaneously predict the pharmacokinetics of CES1 substrates and their active metabolites in liver cirrhosis (LC) patients. Six prodrugs (enalapril, benazepril, cilazapril, temocapril, perindopril and oseltamivir) and three direct-acting drugs (flumazenil, pethidine and remimazolam) were selected. Parameters such as organ blood flows, plasma-binding protein concentrations, functional liver volume, hepatic enzymatic activity, glomerular filtration rate (GFR) and gastrointestinal transit rate were integrated into the simulation. The pharmacokinetic profiles of these drugs and their active metabolites were simulated for 1000 virtual individuals. The developed semi-PBPK model, after validation in healthy individuals, was extrapolated to LC patients. Most of the observations fell within the 5th and 95th percentiles of simulations from 1000 virtual patients. The estimated AUC and Cmax were within 0.5-2-fold of the observed values. The sensitivity analysis showed that the decreased plasma exposure of active metabolites due to the decreased CES1 was partly attenuated by the decreased GFR. Conclusion: The developed PBPK model successfully predicted the pharmacokinetics of CES1 substrates and their metabolites in healthy individuals and LC patients, facilitating tailored dosing of CES1 substrates in LC patients.

Gene polymorphism as a cause of hemorrhagic complications in patients with non-valvular atrial fibrillation treated with oral vitamin K-independent anticoagulants

Atrial fibrillation (AF) accounts for 40% of all cardiac arrhythmias and is associated with a high risk of stroke and systemic thromboembolic complications. Dabigatran, rivaroxaban, apixaban, and edoxaban are direct oral anticoagulants (DOACs) that have been proven to prevent stroke in patients with non-valvular AF. This review summarizes the pharmacokinetics, pharmacodynamics, and drug interactions of DOACs, as well as new data from pharmacogenetic studies of these drugs. This review is aimed at analyzing the scientific literature on the gene polymorphisms involved in the metabolism of DOACs. We searched PubMed, Cochrane, Google Scholar, and CyberLeninka (Russian version) databases with keywords: 'dabigatran', 'apixaban', 'rivaroxaban', 'edoxaban', 'gene polymorphism', 'pharmacogenetics', 'ABCB1', 'CES1', 'SULT1A', 'ABCG2', and 'CYP3A4'. The articles referred for this review include (1) full-text articles; (2) study design with meta-analysis, an observational study in patients taking DOAC; and (3) data on the single-nucleotide polymorphisms and kinetic parameters of DOACs (plasma concentration), or a particular clinical outcome, published in English and Russian languages during the last 10 years. The ages of the patients ranged from 18 to 75 years. Out of 114 reviewed works, 24 were found eligible. As per the available pharmacogenomic data, polymorphisms affecting DOACs are different. This may aid in developing individual approaches to optimize DOAC pharmacotherapy to reduce the risk of hemorrhagic complications. However, large-scale population studies are required to determine the dosage of the new oral anticoagulants based on genotyping. Information on the genetic effects is limited owing to the lack of large-scale studies. Uncovering the mechanisms of the genetic basis of sensitivity to DOACs helps in developing personalized therapy based on patient-specific genetic variants and improves the efficacy and safety of DOACs in the general population.

Pharmacogenomics of Cardiovascular Drugs for Atherothrombotic, Thromboembolic and Atherosclerotic Risk

PURPOSE OF REVIEW

Advances in pharmacogenomics have paved the way for personalized medicine. Cardiovascular diseases still represent the leading cause of mortality in the world. The aim of this review is to summarize the background, rationale, and evidence of pharmacogenomics in cardiovascular medicine, in particular, the use of antiplatelet drugs, anticoagulants, and drugs used for the treatment of dyslipidemia.

RECENT FINDINGS

Randomized clinical trials have supported the role of a genotype-guided approach for antiplatelet therapy in patients with coronary heart disease undergoing percutaneous coronary interventions. Numerous studies demonstrate how the risk of ineffectiveness of new oral anticoagulants and vitamin K anticoagulants is linked to various genetic polymorphisms. Furthermore, there is growing evidence to support the association of some genetic variants and poor adherence to statin therapy, for example, due to the appearance of muscular symptoms. There is evidence for resistance to some drugs for the treatment of dyslipidemia, such as anti-PCSK9.

SUMMARY

Pharmacogenomics has the potential to improve patient care by providing the right drug to the right patient and could guide the identification of new drug therapies for cardiovascular disease. This is very important in cardiovascular diseases, which have high morbidity and mortality. The improvement in therapy could be reflected in the reduction of healthcare costs and patient mortality.

Optimal management of cardiac surgery patients using direct oral anticoagulants: recommendations for clinical practice

OBJECTIVES

Literature is scarce on the management of patients using direct oral anticoagulants (DOACs) undergoing elective, urgent and emergency surgery. Therefore, we summarize the current evidence and provide literature-based recommendations for the management of patients on DOACs in the perioperative phase.

METHODS

A general literature review was conducted on the pharmacology of DOACs and for recommendations on the management of cardiac surgical patients on DOACs. Additionally, we performed a systematic review for studies on the use of direct DOAC reversal agents in the emergency cardiac surgical setting.

RESULTS

When surgery is elective, the DOAC cessation strategy is relatively straightforward and should be adapted to the renal function. The same approach applies to urgent cases, but additional DOAC activity drug level monitoring tests may be useful. In emergency cases, idarucizumab can be safely administered to patients on dabigatran in any of the perioperative phases. However, andexanet alfa, which is not registered for perioperative use, should not be administered in the preoperative phase to reverse the effect of factor Xa inhibitors, as it may induce temporary heparin resistance. Finally, the administration of (activated) prothrombin complex concentrate may be considered in all patients on DOACs, and such concentrates are generally readily available.

CONCLUSIONS

DOACs offer several advantages over vitamin K antagonists, but care must be taken in patients undergoing cardiac surgery. Although elective and urgent cases can be managed relatively straightforwardly, the management of emergency cases requires particular attention.

An in vitro evaluation of kratom (Mitragyna speciosa) on the catalytic activity of carboxylesterase 1 (CES1)

Kratom, (Mitragyna Speciosa Korth.) is a plant indigenous to Southeast Asia whose leaves are cultivated for a variety of medicinal purposes and mostly consumed as powders or tea in the United States. Kratom use has surged in popularity with the lay public and is currently being investigated for possible therapeutic benefits including as a treatment for opioid withdrawal due to the pharmacologic effects of its indole alkaloids. A wide array of psychoactive compounds are found in kratom, with mitragynine being the most abundant alkaloid. The drug-drug interaction (DDI) potential of mitragynine and related alkaloids have been evaluated for effects on the major cytochrome P450s (CYPs) via in vitro assays and limited clinical investigations. However, no thorough assessment of their potential to inhibit the major hepatic hydrolase, carboxylesterase 1 (CES1), exists. The purpose of this study was to evaluate the in vitro inhibitory potential of kratom extracts and its individual major alkaloids using an established CES1 assay and incubation system. Three separate kratom extracts and the major kratom alkaloids mitragynine, speciogynine, speciociliatine, paynantheine, and corynantheidine displayed a concentration-dependent reversible inhibition of CES1. The experimental Ki values were determined as follows for mitragynine, speciociliatine, paynantheine, and corynantheidine: 20.6, 8.6, 26.1, and 12.5 μM respectively. Speciociliatine, paynantheine, and corynantheidine were all determined to be mixed-type reversible inhibitors of CES1, while mitragynine was a purely competitive inhibitor. Based on available pharmacokinetic data, determined Ki values, and a physiologically based inhibition screen mimicking alkaloid exposures in humans, a DDI mediated via CES1 inhibition appears unlikely across a spectrum of doses (i.e., 2-20g per dose). However, further clinical studies need to be conducted to exclude the possibility of a DDI at higher and extreme doses of kratom and those who are chronic users.

Direct Oral Anticoagulant Failures in Atrial Fibrillation With Stroke: Retrospective Admission Analysis and Novel Classification System

Introduction

Breakthrough acute ischemic stroke (AIS) in patients with known, nonvalvular Atrial Fibrillation (AF), on Direct Oral Anticoagulants (DOAC), is an ongoing clinical conundrum. Switching anticoagulants was shown to be ineffective in preventing recurrent AIS. Systematic, patient-level chart review of so-called "DOAC failures" may offer insight into this phenomenon.

Methods

We conducted an IRB-approved, 6-year, retrospective study of AIS admissions, already prescribed DOAC for known AF. We sought plausible, alternative reasons for the AIS using a novel classification schema, CLAMP: C for Compliance concerns, L for Lacunes (small-vessel disease), A for Arteriopathy (atherosclerosis, web, or vasculitis), M for Malignancy, and P for Patent Foramen Ovale (PFO). These categories were labeled as DOAC "Pseudo-failures." Conversely, absence of CLAMP variables were labeled as DOAC "Crypto-failures" conceivably from AF itself ("atriopathy") or pharmacokinetic/pharmacogenomic dysfunction (ie, altered DOAC absorption, clearance, metabolism, or genetic polymorphisms). Forward logistic regression analysis was performed on prespecified DOAC subgroups.

Results

Of 4890 AIS admissions, 606 had AF, and 87 were previously prescribed DOAC (14.4% overall DOAC failure rate, 2.4% annualized over 6 years). Pseudo-failures comprised 77%: Compliance concerns (48.9%), Lacunes (5.7%), Arteriopathy (17.0%), Malignancy (26.1%), and PFO (2.3%). Crypto-failures comprised 23%, had lower CHADSVASc scores (AOR = .65, P = .013), and occurred more with rivaroxaban (41%) than apixaban (16%) or dabigatran (5.6%).

Conclusion

In AIS patients with known AF, DOAC Pseudo-failures, with identified alternate etiologies, are 3 times more likely than DOAC Crypto-failures. The CLAMP schema represents a novel approach to diagnostic classification and therapeutic adjustments in patients already prescribed DOAC for AF.

Cardiovascular precision medicine - A pharmacogenomic perspective

Precision medicine envisages the integration of an individual's clinical and biological features obtained from laboratory tests, imaging, high-throughput omics and health records, to drive a personalised approach to diagnosis and treatment with a higher chance of success. As only up to half of patients respond to medication prescribed following the current one-size-fits-all treatment strategy, the need for a more personalised approach is evident. One of the routes to transforming healthcare through precision medicine is pharmacogenomics (PGx). Around 95% of the population is estimated to carry one or more actionable pharmacogenetic variants and over 75% of adults over 50 years old are on a prescription with a known PGx association. Whilst there are compelling examples of pharmacogenomic implementation in clinical practice, the case for cardiovascular PGx is still evolving. In this review, we shall summarise the current status of PGx in cardiovascular diseases and look at the key enablers and barriers to PGx implementation in clinical practice.

Discovery of seven-membered ring berberine analogues as highly potent and specific hCES2A inhibitors

Human carboxylesterase 2A (hCES2A) is a key serine hydrolase responsible for the metabolic clearance of large number of compounds bearing the ester- or amide-bond(s). Inhibition of hCES2A can relieve the chemotherapy-induced toxicity and alter the pharmacokinetic bahaviors of some orally administrate esters-containing agents. However, most of the hCES2A inhibitors show poor cell-membrane permeability and poor specificity. Herein, guided by the structure activity relationships (SAR) of fifteen natural alkaloids against hCES2A, fifteen new seven-membered ring berberine analogues were designed and synthesized, and their anti-hCES2A activities were evaluated. Among all tested compounds, compound 28 showed potent anti-hCES2A effect (IC₅₀ = 1.66 μM) and excellent selectivity over hCES1A (IC₅₀ > 100 μM). The SAR analysis revealed that the seven-membered ring of these berberine analogues was a crucial moiety for hCES2A inhibition, while the secondary amine group of the ring-C is important for improving their specificity over other serine hydrolases. Inhibition kinetic analyses and molecular dynamic simulation demonstrated that 28 strongly inhibited hCES2A in a mixed-inhibition manner, with an estimated K_i value of 1.035 μM. Moreover, 28 could inhibit intracellular hCES2A in living HepG2 cells and exhibited suitable metabolic stability. Collectively, the SAR of seven-membered ring berberine analogues as hCES2A inhibitors were studied, while compound 28 acted as a promising candidate for developing highly selective hCES2A inhibitors.

Association between the NEP rs701109 polymorphism and the clinical efficacy and safety of sacubitril/valsartan in Chinese patients with heart failure

OBJECTIVE

Sacubitril/valsartan is a commonly used medicine for treating heart failure (HF) patients, but the treatment effects significantly vary. Neprilysin (NEP) and carboxylesterase 1 (CES1) play an important role in the efficacy of sacubitril/valsartan. The purpose of this study was to explore the relationship between NEP and CES1 gene polymorphisms and the efficacy and safety of sacubitril/valsartan treatment in HF patients.

METHODS

Genotyping of 10 single nucleotide polymorphisms (SNPs) of the NEP and CES1 genes in 116 HF patients was performed by the Sequenom MassARRAY method, and logistic regression and haplotype analysis were used to evaluate the associations between SNPs and the clinical efficacy and safety of sacubitril/valsartan in HF patients.

RESULTS

A total of 116 Chinese patients with HF completed the whole trial, and T variations in rs701109 in NEP gene were an independent risk factor (P = 0.013, OR = 3.292, 95% CI:1.287-8.422) for the clinical efficacy of sacubitril/valsartan. Furthermore, haplotype analysis of 6 NEP SNPs (including rs701109) was performed and showed that the CGTACC and TGTACC haplotypes were significantly associated with clinical efficacy (OR = 0.095, 95%CI: 0.012-0.723, P = 0.003; OR = 5.586, 95% CI: 1.621-19.248, P = 0.005). Moreover, no association was found between SNPs of other selected genes in terms of efficacy in HF patients, and no association was observed between SNPs and symptomatic hypotension.

CONCLUSION

Our results suggest an association between rs701109 and sacubitril/valsartan response in HF patients. Symptomatic hypotension is not associated with the presence of NEP polymorphisms.

Effect of Genotype on the Pharmacokinetics and Bleeding Events of Direct Oral Anticoagulants: A Systematic Review and Meta-analysis

This meta-analysis aimed to investigate the effect of the genotype on the pharmacokinetics and bleeding events of direct oral anticoagulants (DOACs) and comprehensively searched electronic databases. Weighted mean difference (WMD) was used to assess the kinetic indicators, odds ratio, and 95% confidence interval (CI) were used to calculate the clinical outcomes. Thirteen articles with 1543 participants were finally included in this study. The peak concentration (C_max ) and area under the plasma concentration-time curve from time 0 to infinity of individuals with the ABCB1 rs 1045642 CT + TT were higher than that of the CC (WMD = -31.9, 95% CI [-49.94, -12.24], P = .02; WMD = -79.97, 95%CI [-152.38 to -7.56], P = .03, I² = 0). The C_max of individuals with mutated genes in ABCB1 2677-3435 is higher than that the wild type (WMD = -19.20, 95%CI [36.62 to -1.79], P = .03, I² = 0). Carriers of the CYP3A5 rs776746 GG genotype had a higher C_max than the GA gene (WMD = -51.22, 95%CI [-92.26 to -10.19], P = .01, I² = 0). Bleeding events were more common in the CES1 rs 2244613 AA + AC than in the CC (odds ratio, 2.62, 95%CI [1.06, 6.47], P = .04; I² = 0). The C_max of DOACs was affected by individuals with ABCB1 rs 1045642, ABCB1 2677-343, and cytochrome P450 3A5 rs 776746. Carriers of the ABCB1 rs 1045642 affected the change of area under the plasma concentration-time curve from time 0 to infinity of DOACs. Bleeding events were affected by CES1 rs 2244613.

The impact of ABCB1 and CES1 polymorphisms on the safety of dabigatran in patients with non-valvular atrial fibrillation

Background

This study aimed to analyze associations between genetic variants and plasma concentrations along with clinical outcomes in dabigatran in patients with non-valvular atrial fibrillation (NVAF).

Methods

We conducted a prospective study and enrolled NVAF patients treated with dabigatran in the real world. A total of 86 patients treated with 110 mg DE twice daily were recruited for this study. Blood samples were obtained from each patient and used for genotyping and determination of plasma dabigatran concentration. All bleeding and thromboembolic complications were recorded during the 1.5 years of follow-up.

Results

Eighty-three patients provided samples at the trough plasma level of dabigatran, and 58 patients provided samples at the peak plasma level of dabigatran. There was a significant association between the CES1 SNP rs8192935 and trough plasma concentrations of dabigatran (P = 0.013). Our results showed that the CES1 SNP rs8192935 significantly influenced dabigatran trough concentrations in the Chinese population, and carriers of the G allele had increased trough plasma concentrations of dabigatran compared to noncarriers. The ABCB1 SNP c.2482-2236G > A (rs4148738) was associated with major bleeding events in the addictive model (P = 0.046, OR = 3.29) and dominant model (P = 0.040, OR = 8.17). Additionally, the ABCB1 SNP c.3435 C > T (rs1045642) was associated with the incidence of major bleeding events in the addictive model (P = 0.043, OR = 3.34) and dominant model (P = 0.046, OR = 7.77). However, no significant associations were found between all the SNPs and the incidence of minor bleeding events.

Conclusion

Our results indicated that the CES1 polymorphism rs8192935 was associated with trough plasma concentrations of dabigatran. Carriers of the G allele had increased trough plasma concentrations of dabigatran compared to noncarriers. The ABCB1 polymorphisms rs4148738 and rs1045642 were associated with an increased risk for major bleeding events for the first time in a Chinese population.

Physiologically-Based Pharmacokinetic Modeling to Predict Methylphenidate Exposure Affected by Interplay Among Carboxylesterase 1 Pharmacogenetics, Drug-Drug Interactions, and Sex

BACKGROUND AND OBJECTIVE

The pharmacokinetics (PK) of methylphenidate (MPH) differ significantly among individuals. Carboxylesterase 1 (CES1) is the primary enzyme metabolizing MPH, and its function is affected by genetic variants, drug-drug interaction (DDI), and sex. The object of this study is to evaluate CES1 pharmacogenetics as related to MPH metabolism using human liver samples and develop a physiologically-based pharmacokinetic (PBPK) modeling approach to investigate the influence of CES1 genotypes and other factors on MPH PK.

METHODS

The effect of the CES1 variant G143E (rs71647871) on MPH metabolism was studied utilizing 102 individual human liver S9 (HLS9) fraction samples. PBPK models were developed using the population-based PBPK software PK-Sim® by incorporating the HLS9 incubation data. The established models were applied to simulate MPH PK profiles under various clinical scenarios, including different genotypes, drug-alcohol interactions, and the difference between males and females.

RESULTS

The HLS9 incubation study showed that subjects heterozygous for the CES1 variant G143E metabolized MPH at a rate of approximately 50% of that in non-carriers. The developed PBPK models successfully predicted the exposure alteration of MPH from the G143E genetic variant, ethanol-MPH DDI, and sex. Importantly, the study suggests that male G143E carriers who are alcohol consumers are at a higher risk of MPH overexposure.

CONCLUSION

PBPK modeling provides a means for better understanding the mechanisms underlying interindividual variability in MPH PK and PD and could be utilized to develop a safer and more effective MPH pharmacotherapy regimen.

Major implications of single nucleotide polymorphisms in human carboxylesterase 1 on substrate bioavailability

The number of studies and reviews conducted for the Carboxylesterase gene is limited in comparison with other enzymes. Carboxylesterase (CES) gene or human carboxylesterases (hCES) is a multigene protein belonging to the α/β-hydrolase family. Over the last decade, two major carboxylesterases (CES1 and CES2), located at 16q13-q22.1 on human chromosome 16 have been extensively studied as important mediators in the metabolism of a wide range of substrates. hCES1 is the most widely expressed enzyme in humans, and it is found in the liver. In this review, details regarding CES1 substrates include both inducers (e.g. Rifampicin) and inhibitors (e.g. Enalapril, Diltiazem, Simvastatin) and different types of hCES1 polymorphisms (nsSNPs) such as rs2244613 and rs71647871. along with their effects on various CES1 substrates were documented. Few instances where the presence of nsSNPs exerted a positive influence on certain substrates which are hydrolyzed via hCES1, such as anti-platelets like Clopidogrel when co-administered with other medications such as angiotensin-converting enzyme (ACE) inhibitors were also recorded. Remdesivir, an ester prodrug is widely used for the treatment of COVID-19, being a CES substrate, it is a potent inhibitor of CES2 and is hydrolyzed via CES1. The details provided in this review could give a clear-cut idea or information that could be used for further studies regarding the safety and efficacy of CES1 substrate.

Association between CES1 rs2244613 and the pharmacokinetics and safety of dabigatran: Meta-analysis and quantitative trait loci analysis

Objective

To date, the influence of the carboxylesterase 1 (CES1) rs2244613 genotype on the pharmacokinetics (PKs) and safety of dabigatran remains controversial. Hence, a systematic review was performed to study the association between CES1 rs2244613 genotype and the PKs and safety of dabigatran and CES1 relative expression.

Methods

In addition to the three English databases (Web of Science, PubMed, and Embase), two Chinese databases (CNKI and Wanfang) were thoroughly revised. The mean differences (MD) and corresponding 95% confidence intervals (CI) were applied to evaluate the differences in PKs between the CES1 rs2244613 genotype. Odds ratio (OR) was used to study the risk for bleeding events between the CES1 rs2244613 genotypes. Subsequent expression quantitative trait loci (eQTL) analyses were performed to evaluate genotype-specific expressions in human tissues.

Results

Ten studies (n = 2,777) were included. CES1 rs2244613 G allele carriers exhibited significantly lower dabigatran trough concentrations compared to T allele carriers (MD: −8.00 ng/mL; 95% CI: −15.08 to −0.92; p = 0.03). The risk for bleeding events was significantly lower in carriers of the G allele compared to T allele carriers (OR: 0.65; 95% CI: 0.44–0.96; p = 0.03). Subsequent eQTL analysis showed significant genome-wide expressions in two human tissues, whole blood (p = 5.1 × 10^–10) and liver (p = 6.2 × 10^–43).

Conclusion

Our meta-analysis indicated a definite relation between the CES1 rs2244613 genotype and tolerability variations or pharmacokinetic fluctuations. The carriers of T allele showed higher dabigatran concentrations; therefore, they would benefit from a dose reduction.

Systematic review registration

[https://inplasy.com/inplasy-2022-6-0027/], identifier [NPLASY202260027].

Genome-Wide Studies in Ischaemic Stroke: Are Genetics Only Useful for Finding Genes?

Ischaemic stroke is a complex disease with some degree of heritability. This means that heritability factors, such as genetics, could be risk factors for ischaemic stroke. The era of genome-wide studies has revealed some of these heritable risk factors, although the data generated by these studies may also be useful in other disciplines. Analysis of these data can be used to understand the biological mechanisms associated with stroke risk and stroke outcome, to determine the causality between stroke and other diseases without the need for expensive clinical trials, or to find potential drug targets with higher success rates than other strategies. In this review we will discuss several of the most relevant studies regarding the genetics of ischaemic stroke and the potential use of the data generated.

The Influence of the CES1 Genotype on the Pharmacokinetics of Enalapril in Patients with Arterial Hypertension

The angiotensin-converting enzyme inhibitor enalapril is hydrolysed to an active metabolite, enalaprilat, in the liver via carboxylesterase 1 (CES1). Previous studies show that variant rs71647871 in the CES1 gene affects the pharmacokinetics of enalapril on liver samples as well as healthy volunteers. This study included 286 Caucasian patients with arterial hypertension who received enalapril. The concentrations of enalapril and enalaprilat were determined before subsequent intake of the drug and 4 h after it with high-performance liquid chromatography (HPLC) and mass spectrometric detection. The study included genetic markers as follows: rs2244613, rs71647871 (c.428G>A, p.G143E) and three SNPs indicating the presence of a subtype CES1A1c (rs12149368, rs111604615 and rs201577108). Mean peak and trough enalaprilat concentrations, adjusted by clinical variables, were significantly lower in CES1 rs2244613 heterozygotes (by 16.6% and 19.6%) and in CC homozygotes (by 32.7% and 41.4%) vs. the AA genotype. In CES1A1c homozygotes, adjusted mean enalaprilat concentrations were 75% lower vs. heterozygotes and wild-type (WT) homozygotes. Pharmacogenetic markers of the CES1 gene may be a promising predictor for individualisation when prescribing enalapril.

Patient-specific genetic factors predict treatment failure in sofosbuvir-treated patients with chronic hepatitis C

BACKGROUND & AIMS

According to pivotal clinical trials, cure rates for sofosbuvir-based antiviral therapy exceed 96%. Treatment failure is usually assumed to be because of virological resistance-associated substitutions or clinical risk factors, yet the role of patient-specific genetic factors has not been well explored. We determined if patient-specific genetic factors help predict patients likely to fail sofosbuvir treatment in real-world treatment situations.

METHODS

We recruited sofosbuvir-treated patients with chronic hepatitis C from five Canadian treatment sites, and performed a case-control pharmacogenomics study assessing both previously published and novel genetic polymorphisms. Specifically studied were variants predicted to impair CES1-dependent production of sofosbuvir's active metabolite, interferon-λ signalling variants expected to impact a patient's immune response to the virus and an HLA variant associated with increased spontaneous and treatment-induced viral clearance.

RESULTS

Three hundred and fifty-nine sofosbuvir-treated patients were available for analyses after exclusions, with 34 (9.5%) failing treatment. We identified CES1 variants as novel predictors for treatment failure in European patients (rs115629050 or rs4513095; odds ratio (OR): 5.43; 95% confidence interval (CI): 1.64-18.01; P = .0057), replicated associations with IFNL4 variants predicted to increase interferon-λ signalling (eg rs12979860; OR: 2.25; 95% CI: 1.25-4.06; P = .0071) and discovered a novel association with a coding variant predicted to enhance the activity of IFNL4's receptor (rs2834167 in IL10RB; OR: 1.81; 95% CI: 1.01-3.24; P = .047).

CONCLUSIONS

Ultimately, this work demonstrates that patient-specific genetic factors could be used as a tool to identify patients at higher risk of treatment failure and allow for these patients to receive effective therapy sooner.

Contributions of Cathepsin A and Carboxylesterase 1 to the Hydrolysis of Tenofovir Alafenamide in the Human Liver, and the Effect of CES1 Genetic Variation on Tenofovir Alafenamide Hydrolysis

The prodrug tenofovir alafenamide (TAF) is a first-line antiviral agent for the treatment of chronic hepatitis B infection. TAF activation involves multiple steps, and the first step is an ester hydrolysis reaction catalyzed by hydrolases. This study was to determine the contributions of carboxylesterase 1 (CES1) and cathepsin A (CatA) to TAF hydrolysis in the human liver. Our in vitro incubation studies showed that both CatA and CES1 catalyzed TAF hydrolysis in a pH-dependent manner. At their physiologic pH environment, the activity of CatA (pH 5.2) was approximately 1,000-fold higher than that of CES1 (pH 7.2). Given that the hepatic protein expression of CatA was approximately 200-fold lower than that of CES1, the contribution of CatA to TAF hydrolysis in the human liver was estimated to be much greater than that of CES1, which is contrary to the previous perception that CES1 is the primary hepatic enzyme hydrolyzing TAF. The findings were further supported by a TAF incubation study with the CatA inhibitor telaprevir and the CES1 inhibitor bis-(p-nitrophenyl) phosphate. Moreover, an in vitro study revealed that the CES1 variant G143E (rs71647871) is a loss-of-function variant for CES1-mediated TAF hydrolysis. In summary, our results suggest that CatA may play a more important role in the hepatic activation of TAF than CES1. Additionally, TAF activation in the liver could be affected by CES1 genetic variation, but the magnitude of impact appears to be limited due to the major contribution of CatA to hepatic TAF activation. SIGNIFICANCE STATEMENT: Contrary to the general perception that carboxylesterase 1 (CES1) is the major enzyme responsible for tenofovir alafenamide (TAF) hydrolysis in the human liver, the present study demonstrated that cathepsin A may play a more significant role in TAF hepatic hydrolysis. Furthermore, the CES1 variant G143E (rs71647871) was found to be a loss-of-function variant for CES1-mediated TAF hydrolysis.

Dabigatran Acylglucuronide, the Major Metabolite of Dabigatran, Shows a Weaker Anticoagulant Effect than Dabigatran

Dabigatran (DAB) is an orally administered thrombin inhibitor. Both DAB and its main metabolite dabigatran acylglucuronide (DABG) have established anticoagulant effects. Here, we aimed to compare the relative anticoagulant effects of DABG and DAB in humans. Anticoagulant effects of DAB and DABG were measured in vitro using a thrombin generation assay. Additionally, their effects on other coagulation assays including PT, aPTT, TT, and fibrinogen were compared. Both DAB and DABG showed inhibitory effects on thrombin generation in a dose-dependent manner, but DABG exhibited a weaker inhibitory effect than that of DAB. The IC₅₀ values of DAB and DABG on thrombin generation AUC were 134.1 ng/mL and 281.9 ng/mL, respectively. DABG also exhibited weaker anticoagulant effects than DAB on PT, aPTT, and TT. The results of the present study indicate that the anticoagulant effect of DABG, a main active DAB metabolite, is weaker than that of DAB.

Transcriptional Regulation of Carboxylesterase 1 in Human Liver: Role of the Nuclear Receptor Subfamily 1 Group H Member 3 and Its Splice Isoforms

Carboxylesterase 1 (CES1) is the predominant carboxylesterase in the human liver, involved in metabolism of both xenobiotics and endogenous substrates. Genetic or epigenetic factors that alter CES1 activity or expression are associated with changes in drug response, lipid, and glucose homeostasis. However, the transcriptional regulation of CES1 in the human liver remains uncertain. By applying both the random forest and Sobol's Sensitivity Indices (SSI) to analyze existing liver RNA expression microarray data (GSE9588), we identified nuclear receptor subfamily 1 group H member 3 (NR1H3) liver X receptor (LXR)α as a key factor regulating constitutive CES1 expression. This model prediction was validated using small interfering RNA (siRNA) knockdown and CRISPR-mediated transcriptional activation of NR1H3 in Huh7 and HepG2 cells. We found that NR1H3's activation of CES1 is splice isoform-specific, namely that increased expression of the NR1H3-211 isoform increased CES1 expression whereas NR1H3-201 did not. Also, in human liver samples, expression of NR1H3-211 and CES1 are correlated, whereas NR1H3-201 and CES1 are not. This trend also occurs during differentiation of induced pluripotent stem cells (iPSCs) to hepatocytes, where only expression of the NR1H3-211 isoform parallels expression of CES1 Moreover, we found that treatment with the NR1H3 agonist T0901317 in HepG2 cells had no effect on CES1 expression. Overall, our results demonstrate a key role of NR1H3 in maintaining the constitutive expression of CES1 in the human liver. Furthermore, our results support that the effect of NR1H3 is splice isoform-specific and appears to be ligand independent. SIGNIFICANCE STATEMENT: Despite the central role of carboxylesterase 1 (CES1) in metabolism of numerous medications, little is known about its transcriptional regulation. This study identifies nuclear receptor subfamily 1 group H member 3 as a key regulator of constitutive CES1 expression and therefore is a potential target for future studies to understand interperson variabilities in CES1 activity and drug metabolism.

Pharmacogenomics Informs Cardiovascular Pharmacotherapy

Precision medicine exemplifies the emergence of personalized treatment options which may benefit specific patient populations based upon their genetic makeup. Application of pharmacogenomics requires an understanding of how genetic variations impact pharmacokinetic and pharmacodynamic properties. This particular approach in pharmacotherapy is helpful because it can assist in and improve clinical decisions. Application of pharmacogenomics to cardiovascular pharmacotherapy provides for the ability of the medical provider to gain critical knowledge on a patient's response to various treatment options and risk of side effects.

Plasma Carboxylesterase 1 Predicts Methylphenidate Exposure: A Proof-of-Concept Study Using Plasma Protein Biomarker for Hepatic Drug Metabolism

Hepatic drug-metabolizing enzymes (DMEs) play critical roles in determining the pharmacokinetics and pharmacodynamics of numerous therapeutic agents. As such, noninvasive biomarkers capable of predicting DME expression in the liver have the potential to be used to personalize pharmacotherapy and improve drug treatment outcomes. In the present study, we quantified carboxylesterase 1 (CES1) protein concentrations in plasma samples collected during a methylphenidate pharmacokinetics study. CES1 is a prominent hepatic enzyme responsible for the metabolism of many medications containing small ester moieties, including methylphenidate. The results revealed a significant inverse correlation between plasma CES1 protein concentrations and the area under the concentration-time curves (AUCs) of plasma d-methylphenidate (P = 0.014, r = -0.617). In addition, when plasma CES1 protein levels were normalized to the plasma concentrations of 24 liver-enriched proteins to account for potential interindividual differences in hepatic protein release rate, the correlation was further improved (P = 0.003, r = -0.703), suggesting that plasma CES1 protein could explain ~ 50% of the variability in d-methylphenidate AUCs in the study participants. A physiologically-based pharmacokinetic modeling simulation revealed that the CES1-based individualized dosing strategy might significantly reduce d-methylphenidate exposure variability in pediatric patients relative to conventional trial and error fixed dosing regimens. This proof-of-concept study indicates that the plasma protein of a hepatic DME may serve as a biomarker for predicting its metabolic function and the pharmacokinetics of its substrate drugs.

Dabigatran plasma concentration indicated the risk of patients with non-valvular atrial fibrillation

This study aimed to evaluate the variability of dabigatran plasma concentration and the association with clinical events in Chinese patients treated with dabigatran etexilate (DE) for non-valvular atrial fibrillation (NVAF). The steady-state concentration of dabigatran (the active metabolite of DE) was determined at trough and peak. The effect of dabigatran concentration variability and related factors on clinical outcomes were explored. Data from 86 patients receiving a fixed dose of 110 mg showed that dabigatran trough concentration varied remarkably. Age, BMI and history of heart failure were identified as important covariates for dabigatran trough concentration. Dabigatran trough concentration (P = 0.002) and history of hypertension (P = 0.012) scores were identified as key factors for predicting the risk of bleeding events. Dabigatran trough concentration, affected by Age, BMI and history of heart failure, may serve as an independent risk factor for bleeding events in Chinese patients treated with DE for NVAF.

Pharmacogenetics to guide cardiovascular drug therapy

Over the past decade, pharmacogenetic testing has emerged in clinical practice to guide selected cardiovascular therapies. The most common implementation in practice is CYP2C19 genotyping to predict clopidogrel response and assist in selecting antiplatelet therapy after percutaneous coronary intervention. Additional examples include genotyping to guide warfarin dosing and statin prescribing. Increasing evidence exists on outcomes with genotype-guided cardiovascular therapies from multiple randomized controlled trials and observational studies. Pharmacogenetic evidence is accumulating for additional cardiovascular medications. However, data for many of these medications are not yet sufficient to support the use of genotyping for drug prescribing. Ultimately, pharmacogenetics might provide a means to individualize drug regimens for complex diseases such as heart failure, in which the treatment armamentarium includes a growing list of medications shown to reduce morbidity and mortality. However, sophisticated analytical approaches are likely to be necessary to dissect the genetic underpinnings of responses to drug combinations. In this Review, we examine the evidence supporting pharmacogenetic testing in cardiovascular medicine, including that available from several clinical trials. In addition, we describe guidelines that support the use of cardiovascular pharmacogenetics, provide examples of clinical implementation of genotype-guided cardiovascular therapies and discuss opportunities for future growth of the field.

Impact of carboxylesterase 1 genetic polymorphism on trandolapril activation in human liver and the pharmacokinetics and pharmacodynamics in healthy volunteers

Trandolapril, an angiotensin-converting enzyme inhibitor prodrug, needs to be activated by carboxylesterase 1 (CES1) in the liver to exert its intended therapeutic effect. A previous in vitro study demonstrated that the CES1 genetic variant G143E (rs71647871) abolished CES1-mediated trandolapril activation in cells transfected with the variant. This study aimed to determine the effect of the G143E variant on trandolapril activation in human livers and the pharmacokinetics (PKs) and pharmacodynamics (PDs) in human subjects. We performed an in vitro incubation study to assess trandolapril activation in human livers (5 G143E heterozygotes and 97 noncarriers) and conducted a single-dose (1 mg) PK and PD study of trandolapril in healthy volunteers (8 G143E heterozygotes and 11 noncarriers). The incubation study revealed that the mean trandolapril activation rate in G143E heterozygous livers was 42% of those not carrying the variant (p = 0.0015). The clinical study showed that, relative to noncarriers, G143E carriers exhibited 20% and 15% decreases, respectively, in the peak concentration (Cmax ) and area under the curve from 0 to 72 h (AUC0-72 h ) of the active metabolite trandolaprilat, although the differences were not statistically significant. Additionally, the average maximum reductions of systolic blood pressure and diastolic blood pressure in carriers were ~ 22% and 23% less than in noncarriers, respectively, but the differences did not reach a statistically significant level. In summary, the CES1 G143E variant markedly impaired trandolapril activation in the human liver under the in vitro incubation conditions; however, this variant had only a modest impact on the PK and PD of trandolapril in healthy human subjects.

Effect of CES1 genetic variation on enalapril steady-state pharmacokinetics and pharmacodynamics in healthy subjects

AIMS

Enalapril is a prodrug and needs to be activated by carboxylesterase 1 (CES1). A previous in vitro study demonstrated the CES1 genetic variant, G143E (rs71647871), significantly impaired enalapril activation. Two previous clinical studies examined the impact of G143E on single-dose enalapril PK (10 mg); however, the results were inconclusive. A prospective, multi-dose, pharmacokinetics and pharmacodynamics (PK/PD) study was conducted to determine the impact of the CES1 G143E variant on enalapril steady-state PK and PD in healthy volunteers.

METHODS

Study participants were stratified to G143E non-carriers (n = 15) and G143E carriers (n = 6). All the carriers were G143E heterozygotes. Study subjects received enalapril 10 mg daily for seven consecutive days prior to a 72 hour PK/PD study. Plasma concentrations of enalapril and its active metabolite enalaprilat were quantified by an established liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.

RESULTS

The CES1 G143E carriers had 30.9% lower enalaprilat C_max (P =  0.03) compared to the non-carriers (38.01 vs. 55.01 ng/mL). The carrier group had 27.5% lower AUC_0-∞ (P =  0.02) of plasma enalaprilat compared to the non-carriers (374.29 vs. 515.91 ng*h/mL). The carriers also had a 32.3% lower enalaprilat-to-enalapril AUC_0-∞ ratio (P =  0.003) relative to the non-carriers. The average maximum reduction of systolic blood pressure in the non-carrier group was approximately 12.4% at the end of the study compared to the baseline (P =  0.001). No statistically significant blood pressure reduction was observed in the G143E carriers.

CONCLUSIONS

The CES1 loss-of-function G143E variant significantly impaired enalapril activation and its systolic blood pressure-lowering effect in healthy volunteers.

The Impact of ABCB1 and CES1 Polymorphisms on Dabigatran Pharmacokinetics in Healthy Chinese Subjects

Dabigatran is a novel direct oral anticoagulant agent, whose plasma concentration is closely related to bleeding risk. Genetic polymorphisms can affect the level of plasma dabigatran. The purpose of this study was to understand the relationship between dabigatran-related genes and the plasma level of dabigatran in healthy Chinese subjects after taking a single oral dose. This study was performed with a single-center, single-dose, randomized, open-label, and four-period crossover trial design under both fasting and fed conditions. A total of 106 eligible healthy subjects were enrolled in the study and 104 were genotyped. One-way analysis of variance (ANOVA) was used to compare pharmacokinetic parameters among different genotypes and linear regression was applied to explore the multiplicative interaction between variables. In this study, we found that the genotype frequencies of CES1 rs2244613 and CES1 rs8192935 were significantly different between Chinese and Caucasians, but the genotype frequencies of ABCB1 rs1045642 and ABCB1 rs4148738 were similar in both populations. CES1 rs8192935 were associated with the peak concentration of dabigatran. There was no significant gender difference in the exposure level of dabigatran. Furthermore, food significantly delayed the absorption of dabigatran but had little effect on C_max and AUC_0-∞.

Using Pharmacogenetics of Direct Oral Anticoagulants to Predict Changes in Their Pharmacokinetics and the Risk of Adverse Drug Reactions

Dabigatran, rivaroxaban, apixaban, and edoxaban are direct oral anticoagulants (DOACs) that are increasingly used worldwide. Taking into account their widespread use for the prevention of thromboembolism in cardiology, neurology, orthopedics, and coronavirus disease 2019 (COVID 19) as well as their different pharmacokinetics and pharmacogenetics dependence, it is critical to explore new opportunities for DOACs administration and predict their dosage when used as monotherapy or in combination with other drugs. In this review, we describe the details of the relative pharmacogenetics on the pharmacokinetics of DOACs as well as new data concerning the clinical characteristics that predetermine the needed dosage and the risk of adverse drug reactions (ADRs). The usefulness of genetic information before and shortly after the initiation of DOACs is also discussed. The reasons for particular attention to these issues are not only new genetic knowledge and genotyping possibilities, but also the risk of serious ADRs (primarily, gastrointestinal bleeding). Taking into account the effect of the carriership of single nucleotide variants (SNVs) of genes encoding biotransformation enzymes and DOACs metabolism, the use of these measures is important to predict changes in pharmacokinetics and the risk of ADRs in patients with a high risk of thromboembolism who receive anticoagulant therapy.

Pharmacokinetics and Pharmacogenetics of Dabigatran

Dabigatran etexilate is a prodrug of dabigatran, a oral direct inhibitor of thrombin. Pharmacokinetics of dabigatran etexilate doesn’t have the disadvantages of vitamin K antagonists. However, pharmacokinetics and pharmacogenetics of dabigatran are variable. This can affect both effectiveness and safety of anticoagulant therapy. It is considered that CES1 enzyme and P-glycoprotein (CES1 and ABCB1 genes accordingly) play important role in pharmacokinetics of dabigatran etexilate. UDP-glucuronosyltransferase enzymes UGT2B15, UGT1A9, UGT2B7 (UGT2B15, UGT1A9, UGT2B7 genes accordingly) take part in the metabolism of active dabigatran. Presence of these gene’s single-nucleotide variants (SNV) can affect effectiveness and safety of dabigatran etexilate usage. The goal of this review is analysis of associated researches of SNV genes CES1 and ABCB1 and search for new candidate genes that reveal effectiveness and safety of dabigatran etexilate usage.

Materials and methods. The search for full-text publications in Russian and English languages containing key words “dabigatran etexilate”, “dabigatran”, “pharmacokinetics”, “effectiveness”, “safety” was carried out amongst literature of the past twenty years with the use of eLibrary, PubMed, Web of Science, OMIM data bases. Pharmacokinetics and pharmacogenetics of dabigatran etexilate are considered in this review. The hypothesis about UDP-glucuronosyltransferase enzymes influence on dabigatran metabolism was examined. Nowadays more than 2000 SNV CES1 and ABCB1 genes are identified, but their potential influence on pharmacokinetics of dabigatran etexilate and its active metabolite (dabigatran) in clinical practice needs to be further researched. Role of SNV UDP-glucuronosyltransferase genes (UGT2B15, UGT1A9, UGT2B7) in dabigatran’s effectiveness and safety is not explored enough. However, UGT2B15 gene can be a potential candidate gene for research on safety of this drug.

Pharmacogenetics of Direct Oral Anticoagulants: A Systematic Review

Dabigatran, rivaroxaban, apixaban, edoxaban, and betrixaban are direct oral anticoagulants (DOACs). Their inter-individual variability in pharmacodynamics and pharmacokinetics (transport and metabolism) is high, and could result from genetic polymorphisms. As recommended by the French Network of Pharmacogenetics (RNPGx), the management of some treatments in cardiovascular diseases (as antiplatelet agents, oral vitamin K antagonists, and statins) can rely on genetic testing in order to improve healthcare by reducing therapeutic resistance or toxicity. This paper is a review of association studies between single nucleotide polymorphisms (SNPs) and systemic exposure variation of DOACs. Most of the results presented here have a lot to do with some SNPs of CES1 (rs2244613, rs8192935, and rs71647871) and ABCB1 (rs1128503, rs2032582, rs1045642, and rs4148738) genes, and dabigatran, rivaroxaban, and apixaban. Regarding edoxaban and betrixaban, as well as SNPs in the CYP3A4 and CYP3A5 genes, literature is scarce, and further studies are needed.

The impact of ABCB1 and CES1 polymorphisms on dabigatran pharmacokinetics and pharmacodynamics in patients with atrial fibrillation

AIMS

Our study aimed to determine the impact of genetic polymorphisms of ABCB1 and CES1 on the pharmacokinetics (PK) and pharmacodynamics (PD) of dabigatran in patients with nonvalvular atrial fibrillation (NVAF).

METHODS

We conducted a prospective study and enrolled NVAF patients treated with dabigatran. Blood samples were obtained from each patient and used for genotyping and determination of plasma dabigatran concentration (PDC) and coagulation parameters including activated partial thromboplastin time (APTT) and thrombin time. Patients' demographics and clinical outcomes from scheduled follow-up visits were all recorded. Statistical analysis was performed to identify the impact of genetic polymorphisms on the PK/PD and bleeding risk of dabigatran.

RESULTS

A total of 198 patients were included in analysis. For the ABCB1 polymorphisms rs4148738 and rs1045642, no significant association was found with dabigatran PK/PD. For the CES1 polymorphism rs8192935, the minor allele(C) was associated with increased trough PDCs (ANOVA: P < .001; CC vs. TT genotype, P < .001; CT vs. TT genotype, P = .014) and with APTT values at trough level (P = .015). For the CES1 polymorphism rs2244613, the minor allele(A) carriers had higher levels of trough PDC than noncarriers (ANOVA: P < .001; AA vs. CC genotype, P < .001; CA vs. CC genotype, P = .004) and increased risk for minor bleeding (P = .034; odds ratio = 2.71, 95% confidence interval 1.05-7.00).

CONCLUSION

Our study indicated that the minor allele(C) on the CES1 SNP rs8192935 was associated with PDCs and APTT values at trough level. The minor allele(A) on the CES1 SNP rs2244613 was associated with increased trough PDCs and higher risk for minor bleeding in NVAF patients treated with dabigatran.

New Pharmacogenetic Markers to Predict the Risk of Bleeding During Taking of Direct Oral Anticoagulants

Aim. To search for new pharmacogenetic biomarkers of bleeding risk in patients taking rivaroxaban and dabigatran for different indications: atrial fibrillation, endoprosthesis of large joints of lower limbs.

Material and methods. The study enrolled 29 patients (17 patients received dabigatran and 12 –rivaroxaban), who had hemorrhagic complications during taking direct oral anticoagulants. To find new pharmacogenetic biomarkers of bleeding risk, a next generation sequencing (NGS) was performed for selected candidate genes.

Results. Among the patients with bleeding who received dabigatran, 13 variants of the nucleotide sequence showed statistically significant deviation from the population values: 11 in the CES1 gene and 2 in the ABCB1 gene. Among the patients with bleeding who received rivaroxaban, 7 variants of nucleotide sequence showed significant deviation: 4 in the ABCG2 gene, 2 in the CYP3A4 gene, and 1 in the ABCB1 gene.

Conclusion. The identified in this study polymorphisms of candidate genes ABCB1, ABCG2, CES1, CYP3A4 were associated with the risk of bleeding in patients taking rivaroxaban and dabigatran. It makes an important contribution to the pharmacogenetics of direct oral anticoagulants and require additional assessment of clinical significance in further studies.

The CES1 Gene rs2244613 Minor Allele Impact on the Safety Profile of Dabigatran Etexilate: Meta-Analysis

Aim. A meta-analysis of studies on the CES1 gene c.1168-33A>C polymorphism (rs2244613) carriage influence on the equilibrium concentration and the risk of bleeding during dabigatran taking.

Material and methods. The search was carried out in the Russian Science Citation Index, Google Academy, Medline PubMed, Embase databases. The meta-analysis included patients who according to the indications (atrial fibrillation, stroke, joint orthopedic surgery) were prescribed dabigatran in various doses. The association was identified in rs2244613 allele C carriers (genotypes AC and CC) and non-carriers (genotype AA). Quantitative synthesis was performed using OpenMetaAnalyst software. In statistical analysis the fixed effects model was used to estimate the influence of the allele C carriage on the any bleeding frequency and the random effects model was used to estimate the influence on the equilibrium plasma concentration level of dabigatran. The homogeneity of the analyzed studies was verified by Cochrane Q-test.

Results. The analysis resulted in selection of 5 works matching all meta-analysis inclusion/exclusion criteria. All selected works included 2030 patients in total. The carriage of the rs2246613 allele C was associated with reduction of risk of any bleeding during dabigatran taking (risk ratio [RR] 0.732, 95% confidence interval [CI] 0.629-0.851; p<0.001). The heterogeneity test did not reveal any reliable differences between the study results (Q=2.183; p=0.535). The level of equilibrium residual concentration of dabigatran was not statistically significant lower for the carriers of C allele of the rs2244613 (mean difference -69.324, 95%CI -236.687-98.039; p=0.417). This might be related to the small sample size and the number of studies included in the meta-analysis. The heterogeneity test did not reveal statistically significant differences between studies (Q=0.388; I2=0%, p=0.534).

Conclusion. The carriage of minor C allelic variant of rs2244613 reduces the risk of any bleeding during dabigatran taking, however, no significant association with decrease in dabigatran concentration was found.

FRACPRED-2D-PRM: A Fraction Prediction Algorithm-Assisted 2D Liquid Chromatography-Based Parallel Reaction Monitoring-Mass Spectrometry Approach for Measuring Low-Abundance Proteins in Human Plasma

Multidimensional fractionation-based enrichment methods improve the sensitivity of proteomic analysis for low-abundance proteins. However, a major limitation of conventional multidimensional proteomics is the extensive labor and instrument time required for analyzing many fractions obtained from the first dimension separation. Here, a fraction prediction algorithm-assisted 2D LC-based parallel reaction monitoring-mass spectrometry (FRACPRED-2D-PRM) approach for measuring low-abundance proteins in human plasma is presented. Plasma digests are separated by the first dimension high-pH RP-LC with data-dependent acquisition (DDA). The FRACPRED algorithm is then usedto predict the retention times of undetectable target peptides according to those of other abundant plasma peptides during the first dimension separation. Fractions predicted to contain target peptides are analyzed by the second dimension low-pH nano RP-LC PRM. The accuracy and robustness of fraction prediction with the FRACPRED algorithm are demonstrated by measuring two low-abundance proteins, aldolase B and carboxylesterase 1, in human plasma. The FRACPRED-2D-PRM proteomics approach demonstrates markedly improved efficiency and sensitivity over conventional 2D-LC proteomics assays. It is expected that this approach will be widely used in the study of low-abundance proteins in plasma and other complex biological samples.

Effect of Sex, Use of Pantoprazole and Polymorphisms in SLC22A1, ABCB1, CES1, CYP3A5 and CYP2D6 on the Pharmacokinetics and Safety of Dabigatran

INTRODUCTION

Dabigatran is a direct oral anticoagulant (DOAC) used for the treatment of several thrombotic conditions. To date, very few pharmacogenetic studies on dabigatran were published. We aimed to investigate the influence of 59 polymorphisms in 15 genes (including CES1, UGT and CYP that encode enzymes and ABCB1 and SLC that encode transporters), concomitant treatment with pantoprazole and demographic characteristics (including sex or race) on dabigatran pharmacokinetics and safety.

METHODS

This was a candidate gene pharmacogenetic study. The study population comprised 107 volunteers enrolled in two dabigatran bioequivalence clinical trials; they were genotyped with a ThermoFisher QuantStudio 12K Flex OpenArray instrument. SPSS software v.21 was used for statistical analysis.

RESULTS

Women showed a higher exposure to dabigatran compared to men. The concomitant treatment with pantoprazole was associated with a decreased exposure to the drug. CYP2D6 poor metabolizers (PMs) were related to lower clearance (Cl/F) (p = 0.049) and a tendency was observed towards higher area under the curve (AUC), maximum concentration (C_max) and to lower volume of distribution (V_d/F) (p < 0.10). SLC22A1 haplotype was related to pharmacokinetic variability (p < 0.05). The remaining genes (including CYP, UGT1A1 and ABCB1) had no effect on dabigatran pharmacokinetics (p > 0.10). Women showed more adverse drug reactions (ADR) compared to men (0.40 ± 0.68 vs 0.15 ± 0.41 ADR per person, p = 0.03) and SLC22A1 mutant haplotype was related to a lower risk of nausea (p = 0.02).

CONCLUSION

Sex, concomitant use of pantoprazole and SLC22A1, CYP2D6 and CYP3A5 polymorphism had an effect on dabigatran pharmacokinetics and safety. Previously published pharmacogenetic predictors, namely CES1 or ABCB1 polymorphisms, had no effect on pharmacokinetics and safety. This study is of interest as it increases the scarce pharmacogenetic information on dabigatran.

A case report of recurrent transient ischaemic attacks on dabigatran for atrial fibrillation: real-world insight into treatment failure

Background 

Non-valvular atrial fibrillation (AF) is an important risk factor for acute ischaemic stroke. There has been an increase in the use of direct-acting oral anticoagulants (DOAC therapy) in stroke prophylaxis due to their convenience and rapid action of onset. However, there is a lack of information in the literature regarding management options and possible mechanisms with the apparent failure of DOAC therapy.

Case summary 

We present a clinical case of a 51-year-old man presenting with transient ischaemic attacks on a background of AF on therapeutic doses of dabigatran. His medication box suggested 100% compliance and his admission coagulation studies showed a marginally prolonged activated partial thromboplastin time and thrombin time (TT). While in hospital, our patient had supervised doses of dabigatran (150 mg b.i.d.). Despite this, his peak dabigatran level was undetectable (<40 ng/mL). With the apparent failure of therapy, he was switched to apixaban 5 mg b.i.d., which showed subsequent peak levels in the target range.

Discussion 

There are a number of isolated case reports of DOAC failure in stroke prophylaxis and management has simply involved switching to another DOAC or warfarin. This case is unique as we have discovered undetectable levels of dabigatran providing a mechanism for failure.

Effect of CES1 and ABCB1 genotypes on the pharmacokinetics and clinical outcomes of dabigatran etexilate in patients with atrial fibrillation and chronic kidney disease

Background Despite the well-studied safety profile of dabigatran, its interactions with genetic polymorphism parameters are poorly understood, especially in patients with moderate chronic kidney disease (CKD). The study assessed whether genetic factors can contribute to CKD and alter dabigatran concentration. Methods Patients with atrial fibrillation (AF) and stage 3 CKD treated with dabigatran 110 or 150 mg have been included in the study. Real-time polymerase chain reaction was used to evaluate single-nucleotide polymorphisms of the ABCB1 gene (rs1045642 and rs4148738) and CES1 gene (rs2244613). A plasma trough concentration/dose (C/D) ratio was used as a pharmacokinetic index. Results A total of 96 patients aged 51-89 years (median age: 75 years) were evaluated. Patients on a reduced regimen of 110 mg twice a day were older (79.8 vs. 67.9, p < 0.0001) and had lower creatinine clearance (49.7 vs. 62.3 mL/min/1.73 m2, p = 0.015). Patients with the rs2244613 CC genotype had lower C/D values (70% reduction in the mean C/D vs. AA genotype, p = 0.001). Linear stepwise regression has shown the CKD epidemiology collaboration to be the only significant predictor of C/D among genetic factors and kidney function characteristics. During the median follow-up of 15 months, there were 15 bleedings in 13 patients. Conclusions Polymorphism of CES1 rs2244613 can contribute to the safety of dabigatran in patients with AF and CKD. There was no influence of the aforementioned polymorphisms of ABCB1 on dabigatran trough plasma concentrations and C/D. Kidney function is a mainstay of clinical decision-making on direct oral anticoagulant (DOAC) dose, and further knowledge should be accumulated on the role of genetic factors.

Carboxylesterase 1 and Precision Pharmacotherapy: Pharmacogenetics and Nongenetic Regulators

Carboxylesterase (CES) 1 is the most abundant drug-metabolizing enzyme in human livers, comprising approximately 1% of the entire liver proteome. CES1 is responsible for 80%-95% of total hydrolytic activity in the liver and plays a crucial role in the metabolism of a wide range of drugs (especially ester-prodrugs), pesticides, environmental pollutants, and endogenous compounds. Expression and activity of CES1 vary markedly among individuals, which is a major contributing factor to interindividual variability in the pharmacokinetics (PK) and pharmacodynamics (PD) of drugs metabolized by CES1. Both genetic and nongenetic factors contribute to CES1 variability. Here, we discuss genetic polymorphisms, including single-nucleotide polymorphisms (SNPs), and copy number variants and nongenetic contributors, such as developmental status, genders, and drug-drug interactions, that could influence CES1 functionality and the PK and PD of CES1 substrates. Currently, the loss-of-function SNP G143E (rs71647871) is the only clinically significant CES1 variant identified to date, and alcohol is the only potent CES1 inhibitor that could alter the therapeutic outcomes of CES1 substrate medications. However, G143E and alcohol can only explain a small portion of the interindividual variability in the CES1 function. A better understanding of the regulation of CES1 expression and activity and identification of biomarkers for CES1 function in vivo could lead to the development of a precision pharmacotherapy strategy to improve the efficacy and safety of many CES1 substrate drugs. SIGNIFICANCE STATEMENT: The clinical relevance of CES1 has been well demonstrated in various clinical trials. Genetic and nongenetic regulators can affect CES1 expression and activity, resulting in the alteration of the metabolism and clinical outcome of CES1 substrate drugs, such as methylphenidate and clopidogrel. Predicting the hepatic CES1 function can provide clinical guidance to optimize pharmacotherapy of numerous medications metabolized by CES1.

Effects of the rs2244613 polymorphism of the CES1 gene on the antiplatelet effect of the receptor P2Y12 blocker clopidogrel

Background The aim of this study was to evaluate the association of the carriage of the rs2244613 polymorphism of the CES1 gene with clopidogrel resistance as well as to evaluate the effectiveness of antiplatelet therapy in the carriers of this marker who have had acute coronary syndrome (ACS). This study also analyzes the procedure of percutaneous coronary intervention and compares the rs2244613 carrier rate between patients with ACS and healthy participants. Methods The study involved 81 patients diagnosed with ACS and 136 conditionally healthy participants. The optical detection of platelet agglutination by VerifyNow was employed to measure residual platelet reactivity in patients with ACS. The rs2244613 polymorphism was determined using real-time polymerase chain reaction. Results According to the results, the AA genotype of the rs2244613 polymorphism of the CES1 gene was detected in 37 patients (45.6%), the CA genotype in 42 patients (51.8%) and the CC genotype in 2 patients (2.6%). The level of residual platelet reactivity in rs2244613 carriers was higher compared with patients who did not have this allelic variant: 183.23 PRU ± 37.24 vs. 154.3 PRU ± 60.36 (p = 0.01). The frequencies of the minor allele C were 28.4% and 28.3% in patients with ACS and healthy participants, respectively. The results of the linear statistical model PRU due to CES1 genotype were as follows: df = 1, F = 6.96, p = 0.01). The standardized beta was 0.285 (p = 0.01) and R2 was 0.081. However, we also added CYP2C19*2 and *17 into the linear regression model. The results of the model were as follows: df = 3, F = 5.1, p = 0.003) and R2 was 0.166. Conclusions We identified a statistically significant correlation between the carriage of the rs2244613 polymorphism of the CES1 gene and the level of residual platelet aggregation among patients with ACS and the procedure of percutaneous coronary intervention.

[Comparative clinical and economic evaluation of pharmacogenetic testing application for dabigatran in patients with atrial fibrillation]

AIM

To evaluate the clinical and economic feasibility of pharmacogenetic testing (PGT) for dabigataran etexilate administration in the treatment of atrial fibrillation (AF) without valve in comparison with tactics without pharmacogenetic testing.

MATERIALS AND METHODS

The pharmacoeconomic model was done using generalized data from published clinical, epidemiological and clinical - economic studies.

RESULTS AND DISCUSSION

Application of PGT on the carrier of allelic variant rs2244613 of CES1 gene for adjustment of dabigatrane etexilate dosage in patients with non - valve AF may be more cost - effective strategy for prevention of thromboembolic complications in patients with non - valve AF. Thus, due to the decrease in the number of undesirable drug reactions in the form of minor and major bleedings, the difference in treatment costs in the group with PGT compared to the group with standard pharmacotherapy tactics per 100 patients was 11 827.65 rubles. The expected cost per patient per year for standard treatment was 36 051.35 rubles, while in the group with PGT it was 35 933.07 rubles. The difference was 1182.76 rubles in favor of the pharmacogenetic approach Conclusion. A PGT approach to correct dabigatrane dosage can reduce the cost of pharmacotherapy by reducing the risk of adverse reactions of minor and major bleeding.