Characterisation of exposure versus response of edoxaban in patients undergoing total hip replacement surgery

Can edoxaban be used at extremes of bodyweight and in patients with a creatinine clearance ≥95 ml/min? - A population pharmacokinetic analysis

BACKGROUND

Clinical evidence surrounding edoxaban use in patients weighing <50 kg and >120 kg is lacking. The International Society of Thrombosis and Haemostasis Scientific and Standardisation Committee suggests avoiding edoxaban in patients >120 kg. Additionally, concerns exist regarding decreased efficacy in patients prescribed edoxaban for atrial fibrillation with a creatinine clearance (CrCl) >95 ml/min, a finding of the ENGAGE AF-TIMI 48 trial when edoxaban was compared to warfarin.

OBJECTIVE

To derive a population pharmacokinetic (PopPK) model using clinical practice data, to understand the impact of bodyweight and renal function on edoxaban pharmacokinetics.

METHOD

Edoxaban plasma concentrations and patient characteristics were collated from King's College Hospital anticoagulation clinics between 11/2016 and 08/2022. A PopPK model was developed using non-linear mixed effects modelling and used to simulate edoxaban concentrations at the extremes of bodyweight and with varying renal function.

RESULTS

Data from 409 patients (46 < 50 kg, 34 > 120 kg and 123 with a CrCl > 95 ml/min) provided 455 edoxaban plasma concentrations. A one-compartment model with between-subject variability on clearance with a proportional error model best described the data. The most significant covariates impacting on edoxaban exposure were CrCl and bodyweight. Our work suggests that edoxaban exposure in patients weighing up to 140 kg is comparable to those weighing 75 kg. Edoxaban exposure is reduced in patients weighing <50 kg due to the recommended dose reductions. There is also a reduction in AUCss when CrCl > 95 ml/min compared to CrCl 80 ml/min.

CONCLUSIONS

Our population PK model for edoxaban suggests that renal function is a key driver for overall edoxaban exposure. Further clinical outcome data is required to understand clinical effectiveness and adverse outcomes.

Influence of Renal Function on the Pharmacokinetics, Pharmacodynamics, Efficacy, and Safety of Non-Vitamin K Antagonist Oral Anticoagulants

With the growing integration of non-vitamin K antagonist oral anticoagulants (NOACs) into clinical practice, questions have arisen regarding their use in special populations, including groups that may have been underrepresented in clinical trials. Patients with renal impairment, particularly in the lower echelons of renal function, are one such group. In an effort to elucidate the current evidence regarding the use of NOACs in patients with renal impairment, a systematic assessment of the literature was performed. The MEDLINE database was interrogated for studies and analyses evaluating the influence of renal function on the pharmacokinetics, pharmacodynamics, efficacy, and safety of NOACs published from January 1, 2000, through August 2, 2017. The 82 relevant publications retrieved highlight the diversity in the NOAC class regarding the impact of renal function on drug clearance, drug exposures, and clinical trial outcomes. In several large clinical trials, subgroup analyses revealed no significant differences when patients were stratified by creatinine clearance as a measure of renal function. Efficacy findings, in particular, were largely aligned with the overall population in the included studies. However, relative risks of bleeding were shown to vary, sometimes driven by changes in bleeding event rates in the comparator arm (eg, warfarin, enoxaparin). With few exceptions, minimal influence of mild renal impairment was observed on the relative efficacy and safety of NOACs. Taken together, the evidence suggests that the presence of renal impairment merits careful consideration of anticoagulant choice but should not deter physicians from appropriate use of NOACs.

Population Pharmacokinetics of Edoxaban in Patients with Non-Valvular Atrial Fibrillation in the ENGAGE AF-TIMI 48 Study, a Phase III Clinical Trial

INTRODUCTION

Edoxaban is a novel factor Xa inhibitor. This study characterizes the population pharmacokinetics of edoxaban in patients with non-valvular atrial fibrillation (NVAF) included in the phase III ENGAGE AF-TIMI 48 study, evaluates covariates for the dose-exposure relationship in this population, and assesses the impact of protocol-specified dose reductions on exposure using simulations.

METHODS

Model development was performed using NONMEM(®) and based on sparse data from the ENGAGE AF-TIMI 48 study augmented with dense data from 13 phase I studies to inform and stabilize the model. The influence of body weight (WT), creatinine clearance (CLCR), concomitant P-glycoprotein (P-gp) inhibitors, age, sex, race, and NVAF on pharmacokinetic parameters was evaluated based on statistical significance and clinical relevance.

RESULTS

A two-compartment model with first-order elimination and first-order absorption after an absorption lag-time best described the data. Apparent volume and clearance terms increased with increasing WT. Apparent renal clearance increased with increasing CLCR. Apparent non-renal, renal, and inter-compartmental clearance terms differed between phase I volunteers and NVAF patients. Asian patients were found to have increased apparent central volume of distribution, bioavailability, and total apparent clearance. Concomitant P-gp inhibitors increased the bioavailability statistically significantly, but this did not reach clinical relevance.

CONCLUSION

Edoxaban disposition and the variability in this disposition, including influence of covariates, after oral administration were adequately characterized in patients with NVAF. The 50 % dose reduction in patients with low WT (≤60 kg), moderate renal impairment (CLCR ≤50 mL/min), or concomitant P-gp inhibitors led to 30 % lower exposure than in the other patients.

Review of the Target-Specific Oral Anticoagulants in Development for the Treatment and Prevention of Venous Thromboembolism

Anticoagulation therapy is often indicated for the treatment and prevention of venous thromboembolism (VTE). Despite advances in anticoagulant management with parenteral anticoagulants and vitamin K antagonists, limitations to their use still exists, leading to investigation of alternative anticoagulants such as factor Xa inhibitors and direct thrombin inhibitors. To date, 3 target-specific oral anticoagulants (TSOACs) are Food and Drug Administration approved; several other agents are currently in development to optimize VTE management and minimize bleeding risks. The objective of this systematic review article is to provide clinicians an overview of the clinical evidence on the investigational TSOACs for the treatment and prevention of VTE. Of the agents in development, edoxaban holds the most promise due to robust data supporting its clinical benefit with a similar bleeding risk to currently approved agents. Clinicians should understand the TSOACs under investigation, since differences in pharmacokinetics and pharmacodynamics may influence clinical decision making and agent selection for management of VTE. Currently, no direct comparisons between TSOACs have been conducted. Agents under investigation have yet to overcome the major limitations of the currently existing TSOACs. Further studies are necessary to clarify which TSOAC agent is best for management of VTE in clinical practice.

The Use of Edoxaban in Patients with Nonvalvular Atrial Fibrillation and Venous Thromboembolism: A Pharmacist's Perspective

Until 2010, the vitamin K antagonist warfarin was the only available oral anticoagulant for the prevention of stroke or systemic embolic events (SEE) in patients with nonvalvular atrial fibrillation (NVAF) and the treatment of venous thromboembolism (VTE) in the United States. Despite its proven efficacy, the use of warfarin is limited by numerous disadvantages, including a delayed onset of action and variable efficacy resulting from interactions with genetic and environmental factors. Consequently, optimal anticoagulation with warfarin requires dose adjustments based on frequent monitoring. In contrast to warfarin, direct oral anticoagulants (DOACs) including dabigatran, rivaroxaban, apixaban, and edoxaban have predictable pharmacokinetic profiles, few drug-drug interactions, no known interactions with food, and can be administered at fixed doses without the requirement for routine monitoring. All DOACs have received US Food and Drug Administration (FDA) approval for the prevention of stroke or SEE in patients with NVAF and the treatment of VTE based on phase 3 trials demonstrating that they are at least as efficacious as warfarin. In addition, the incidence of clinically relevant bleeding associated with DOACs is comparable to or lower than with warfarin. In this article, the preclinical and clinical data that led to the FDA approval of once-daily edoxaban in January 2015 are presented. Furthermore, practical considerations for edoxaban use including dosing recommendations, transitions of care, reversal of anticoagulation, precautions, contraindications, and cost-effectiveness are discussed. Edoxaban is an important addition to oral anticoagulation options available for the therapeutic management of patients with NVAF or VTE.

Population pharmacokinetics of edoxaban in patients with symptomatic deep-vein thrombosis and/or pulmonary embolism--the Hokusai-VTE phase 3 study

AIMS

This study characterized the population pharmacokinetics of edoxaban in patients with symptomatic deep-vein thrombosis and/or pulmonary embolism in the Hokusai-VTE phase 3 study. The impact of the protocol-specified 50% dose reductions applied to patients with body weight ≤ 60 kg, creatinine clearance (CL(cr)) of 30 to 50 ml min(-1) or concomitant P-glycoprotein inhibitor on edoxaban exposure was assessed using simulations.

METHODS

The sparse data from Hokusai-VTE, 9531 concentrations collected from 3707 patients, were pooled with data from 13 phase 1 studies. In the analysis, the covariate relationships used for dose reductions were estimated and differences between healthy subjects and patients as well as additional covariate effects of age, race and gender were explored based on statistical and clinical significance.

RESULTS

A linear two-compartment model with first order absorption preceded by a lag time best described the data. Allometrically scaled body weight was included on disposition parameters. Apparent clearance was parameterized as non-renal and renal. The latter increased non-linearly with increasing CL(cr). Compared with healthy volunteers, inter-compartmental clearance and the CL(cr) covariate effect were different in patients (+64.6% and +274%). Asian patients had a 22.6% increased apparent central volume of distribution. The effect of co-administration of P-glycoprotein inhibitors seen in phase 1 could not be confirmed in the phase 3 data. Model-based simulations revealed lower exposure in dose-reduced compared with non-dose-reduced patients.

CONCLUSIONS

The adopted dose-reduction strategy resulted in reduced exposure compared with non-dose-reduced, thereby overcompensating for covariate effects. The clinical impact of these differences on safety and efficacy remains to be evaluated.

Update on Edoxaban for the Prevention and Treatment of Thromboembolism: Clinical Applications Based on Current Evidence

Vitamin K antagonists (VKA) and heparins have been utilized for the prevention and treatment of thromboembolism (arterial and venous) for decades. Targeting and inhibiting specific coagulation factors have led to new discoveries in the pharmacotherapy of thromboembolism management. These targeted anticoagulants are known as direct oral anticoagulants (DOACs). Two pharmacologically distinct classes of targeted agents are dabigatran etexilate (Direct Thrombin Inhibitor (DTI)) and rivaroxaban, apixaban, and edoxaban (direct oral factor Xa inhibitors (OFXaIs)). Emerging evidence from the clinical trials has shown that DOACs are noninferior to VKA or low-molecular-weight heparins in the prevention and treatment of thromboembolism. This review examines the role of edoxaban, a recently approved OFXaI, in the prevention and treatment of thromboembolism based on the available published literature. The management of edoxaban in the perioperative setting, reversibility in bleeding cases, its role in cancer patients, the relevance of drug-drug interactions, patient satisfaction, financial impacts, and patient education will be discussed.

Efficacy and safety of edoxaban versus enoxaparin for the prevention of venous thromboembolism following total hip arthroplasty: STARS J-V

BACKGROUND

In the absence of thromboprophylaxis, patients undergoing total hip arthroplasty (THA) are at increased risk for venous thromboembolism (VTE). The objective of this study was to compare the efficacy and safety of edoxaban with enoxaparin for the prevention of VTE after THA in Japan.

METHODS

This was a phase 3, double-blind, double-dummy, noninferiority study. Patients undergoing elective, unilateral primary THA were randomized to receive edoxaban 30 mg once daily (n = 307) or enoxaparin 2000 IU (equivalent to 20 mg) twice daily (n = 303) for 11 to 14 days. The primary efficacy endpoint was the incidence of VTE. Safety endpoints included the incidence of major or clinically relevant nonmajor (CRNM) bleeding.

RESULTS

The incidence of VTE, based on venography and clinical surveillance, was 2.4 % in the edoxaban group and 6.9 % in the enoxaparin group (P <0.001). The absolute difference in the incidence of VTE was -4.5 % (95 % confidence interval [CI]: -8.6, -0.9), which was within the noninferiority margin set at 8 % for the difference and established the noninferiority of edoxaban to enoxaparin. Since the upper limit of the 95 % CI of the absolute difference was less than 0 %, the superiority of edoxaban over enoxaparin was demonstrated. The incidence of major or CRNM bleeding was 2.6 % in the edoxaban group and 3.7 % in the enoxaparin group (P = 0.475).

CONCLUSIONS

Oral edoxaban 30 mg once daily was superior to subcutaneous enoxaparin 2000 IU twice daily in the prevention of VTE following THA without increasing the risk for major or CRNM bleeding.

Population pharmacokinetics of edoxaban and its main metabolite in a dedicated renal impairment study

A model characterizing the population pharmacokinetics (PK) of edoxaban and its major metabolite, M4, following a single oral dose of 15 mg administered to subjects with varying kidney function was developed. Thirty-two subjects contributed with edoxaban plasma, edoxaban urine, and M4 plasma concentrations. Edoxaban urine concentrations allowed estimation of renal clearance, and high contribution of renal to total clearance enabled estimation of absolute oral bioavailability. A 2-compartment model with delayed absorption and elimination parameterized as renal clearance linearly related to creatinine clearance (CLcr ) and nonrenal clearance forming M4 described edoxaban PK. The PK of M4 was described with a 1-compartment model. For a typical subject (70 kg; CLcr , 100 mL/min) bioavailability, clearance, and central and peripheral volume of distribution for edoxaban was estimated to 72.3%, 21.0 L/h, 95.4 L, and 54.3 L, respectively. For both edoxaban and M4, the model predicted systemic exposure to increase 57.0%, 35.0%, and 11.6% in a subject having CLcr of 30, 50, and 80 mL/min, respectively, compared with a subject having a CLcr of 100 mL/min. Concentration ratios (M4 over edoxaban) were predicted to vary with time after dose, but with minor influence of kidney function and body weight. Results were in agreement with previous analyses.

Using new oral anticoagulants in patients undergoing major orthopedic surgery

Four new oral anticoagulants (NOAC), apixaban, rivaroxaban, edoxaban, and dabigatran, are now available in the USA; however, only apixaban and rivaroxaban are FDA approved for the prevention of venous thromboembolism following orthopedic surgery. Apixaban, rivaroxaban, and edoxaban's anticoagulant activity can be measured using a chromogenic anti-factor Xa assay but there is no widely available means of measuring dabigatran blood levels. None of the NOAC has an antidote. Dabigatran is 80% renally excreted, and patients with atrial fibrillation taking dabigatran for stroke prevention should stop the drug 4-5 days prior to major orthopedic surgery. Apixaban, rivaroxaban, and edoxaban should be held for 48 h preoperatively in this setting.

A randomized, open-label trial of edoxaban in Japanese patients with severe renal impairment undergoing lower-limb orthopedic surgery

Background

Edoxaban is an oral, direct, factor Xa inhibitor approved in Japan for thromboembolic prophylaxis after lower-limb orthopedic surgery (LLOS), but contraindicated in patients with severe renal impairment (SRI; creatinine clearance [CL_CR] ≥15 to <30 mL/min).

Methods

This open-label study compared the safety of edoxaban 15 mg once daily in Japanese patients with SRI to that of edoxaban 30 mg in patients with mild renal impairment (MiRI; CL_CR ≥50 to ≤80 mL/min; N = 30) undergoing LLOS. Patients with CL_CR ≥20 to <30 mL/min were randomized to receive edoxaban 15 mg (N = 22) or subcutaneous fondaparinux 1.5 mg once daily (N = 21). All patients with CL_CR ≥15 to <20 mL/min received edoxaban 15 mg (N = 7). Treatment was administered for 11 to 14 days.

Results

Major or clinically relevant non-major bleeding occurred in 6.7%, 3.4%, and 5.0% of patients in the MiRI edoxaban 30-mg, SRI edoxaban 15-mg, and SRI fondaparinux groups, respectively; there were no major bleeding events. No thromboembolic events occurred. At all time points assessed, edoxaban plasma concentrations and changes in coagulation biomarkers were similar between the SRI and MiRI groups.

Conclusions

These results suggest edoxaban 15 mg once daily is well tolerated in Japanese patients with SRI undergoing LLOS.

Trial registration

Clinicaltrials.gov Identifier: NCT01857583.

Electronic supplementary material

The online version of this article (doi:10.1186/s12959-014-0034-9) contains supplementary material, which is available to authorized users.

Pharmacology and laboratory testing of the oral Xa inhibitors

New oral factor Xa inhibitors are intended to progressively substitute the oral vitamin K antagonists and parenteral indirect inhibitors of factor Xa in the prevention and treatment of venous and arterial thromboembolic episodes. This article focuses on the main clinical studies and on biological measurements of new oral factor Xa inhibitors, and addresses several safety issues. These newer agents do not require any routine laboratory monitoring of blood coagulation; however, biological tests have been developed in order to assess the plasma concentration of these drugs in several clinical settings. This article reviews these 4 oral direct factor Xa inhibitors.

The pharmacokinetics of edoxaban for the prevention and treatment of venous thromboembolism

INTRODUCTION

Thromboembolic diseases will become the most important contributors to mortality and morbidity for modern societies. Current antithrombotic strategies using heparins or vitamin K antagonists are inconvenient, with limitations and inherent side effects. A series of new oral anticoagulants with powerful and reliable antithrombotic actions have been developed in the last decade.

AREAS COVERED

Edoxaban is a direct and specific inhibitor of activated factor X, delivered orally. This article reviews literature from PubMed and articles referenced within. The text explores the pharmacological aspects of its antithrombotic action. Pharmacokinetics, metabolism and drug interactions are examined. The review places the results of recent clinical trials that have evaluated the antithrombotic potential of edoxaban versus standard antithrombotic therapies in the prophylaxis and treatment of venous thromboembolism into perspective. The possible relationship between the pharmacokinetic profile of edoxaban and the favorable results in clinical trials is discussed.

EXPERT OPINION

Edoxaban is perceived as a major advance, compared to vitamin K antagonists, in the prevention and treatment of thromboembolic disease given its favorable efficacy, safety, pharmacokinetic profile and renal clearance. The results of ongoing large international trials exploring the prevention of thrombotic complications in patients in different clinical settings should ensure the approval of edoxaban to treat new indications.