Michael A. Grosso

Edoxaban versus Warfarin for the Treatment of Symptomatic Venous Thromboembolism

BACKGROUND Whether the oral factor Xa inhibitor edoxaban can be an alternative to warfarin in patients with venous thromboembolism is unclear. METHODS In a randomized, double-blind, noninferiority study, we randomly assigned patients with acute venous thromboembolism, who had initially received heparin, to receive edoxaban at a dose of 60 mg once daily, or 30 mg once daily (e.g., in the case of patients with creatinine clearance of 30 to 50 ml per minute or a body weight below 60 kg), or to receive warfarin. Patients received the study drug for 3 to 12 months. The primary efficacy outcome was recurrent symptomatic venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding. RESULTS A total of 4921 patients presented with deep-vein thrombosis, and 3319 with a pulmonary embolism. Among patients receiving warfarin, the time in the therapeutic range was 63.5%. Edoxaban was noninferior to warfarin with respect to the primary efficacy outcome, which occurred in 130 patients in the edoxaban group (3.2%) and 146 patients in the warfarin group (3.5%) (hazard ratio, 0.89; 95% confidence interval [CI], 0.70 to 1.13; P<0.001 for noninferiority). The safety outcome occurred in 349 patients (8.5%) in the edoxaban group and 423 patients (10.3%) in the warfarin group (hazard ratio, 0.81; 95% CI, 0.71 to 0.94; P=0.004 for superiority). The rates of other adverse events were similar in the two groups. A total of 938 patients with pulmonary embolism had right ventricular dysfunction, as assessed by measurement of N-terminal pro-brain natriuretic peptide levels; the rate of recurrent venous thromboembolism in this subgroup was 3.3% in the edoxaban group and 6.2% in the warfarin group (hazard ratio, 0.52; 95% CI, 0.28 to 0.98). CONCLUSIONS Edoxaban administered once daily after initial treatment with heparin was noninferior to high-quality standard therapy and caused significantly less bleeding in a broad spectrum of patients with venous thromboembolism, including those with severe pulmonary embolism. (Funded by Daiichi-Sankyo; Hokusai-VTE ClinicalTrials.gov number, NCT00986154.).

Use of PER977 to reverse the anticoagulant effect of edoxaban.

Among 80 healthy persons who had received a single dose of edoxaban, the whole-blood clotting time was reduced significantly more rapidly in those who received the novel small molecule PER977 than in controls who were not given PER977.

Edoxaban Effects on Bleeding Following Punch Biopsy and Reversal by a 4-Factor Prothrombin Complex Concentrate

Background— The oral factor Xa inhibitor edoxaban has demonstrated safety and efficacy in stroke prevention in patients with atrial fibrillation and in the treatment and secondary prevention of venous thromboembolism. This study investigated the reversal of edoxaban’s effects on bleeding measures and biomarkers by using a 4-factor prothrombin complex concentrate (4F-PCC). Methods and Results— This was a phase 1 study conducted at a single site. This was a double-blind, randomized, placebo-controlled, 2-way crossover study to determine the reversal effect of descending doses of 4F-PCC on bleeding duration and bleeding volume following edoxaban treatment. A total of 110 subjects (17 in part 1, 93 in part 2) were treated. Intravenous administration of 4F-PCC 50, 25, or 10 IU/kg following administration of edoxaban (60 mg) dose-dependently reversed edoxaban’s effects on bleeding duration and endogenous thrombin potential, with complete reversal at 50 IU/kg. Effects on prothrombin time were partially reversed at 50 IU/kg. A similar trend was seen for bleeding volume. Conclusions— The 4F-PCC dose-dependently reversed the effects of edoxaban (60 mg), with complete reversal of bleeding duration and endogenous thrombin potential and partial reversal of prothrombin time following 50 IU/kg. Edoxaban alone and in combination with 4F-PCC was safe and well tolerated in these healthy subjects. A dose of 50 IU/kg 4F-PCC may be suitable for reversing edoxaban anticoagulation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT02047565.

Edoxaban for the Treatment of Cancer-Associated Venous Thromboembolism

Background Low‐molecular‐weight heparin is the standard treatment for cancer‐associated venous thromboembolism. The role of treatment with direct oral anticoagulant agents is unclear. Methods In this open‐label, noninferiority trial, we randomly assigned patients with cancer who had acute symptomatic or incidental venous thromboembolism to receive either low‐molecular‐weight heparin for at least 5 days followed by oral edoxaban at a dose of 60 mg once daily (edoxaban group) or subcutaneous dalteparin at a dose of 200 IU per kilogram of body weight once daily for 1 month followed by dalteparin at a dose of 150 IU per kilogram once daily (dalteparin group). Treatment was given for at least 6 months and up to 12 months. The primary outcome was a composite of recurrent venous thromboembolism or major bleeding during the 12 months after randomization, regardless of treatment duration. Results Of the 1050 patients who underwent randomization, 1046 were included in the modified intention‐to‐treat analysis. A primary‐outcome event occurred in 67 of the 522 patients (12.8%) in the edoxaban group as compared with 71 of the 524 patients (13.5%) in the dalteparin group (hazard ratio, 0.97; 95% confidence interval [CI], 0.70 to 1.36; P=0.006 for noninferiority; P=0.87 for superiority). Recurrent venous thromboembolism occurred in 41 patients (7.9%) in the edoxaban group and in 59 patients (11.3%) in the dalteparin group (difference in risk, ‐3.4 percentage points; 95% CI, ‐7.0 to 0.2). Major bleeding occurred in 36 patients (6.9%) in the edoxaban group and in 21 patients (4.0%) in the dalteparin group (difference in risk, 2.9 percentage points; 95% CI, 0.1 to 5.6). Conclusions Oral edoxaban was noninferior to subcutaneous dalteparin with respect to the composite outcome of recurrent venous thromboembolism or major bleeding. The rate of recurrent venous thromboembolism was lower but the rate of major bleeding was higher with edoxaban than with dalteparin. (Funded by Daiichi Sankyo; Hokusai VTE Cancer ClinicalTrials.gov number, NCT02073682.)

Edoxaban versus enoxaparin–warfarin in patients undergoing cardioversion of atrial fibrillation (ENSURE-AF): a randomised, open-label, phase 3b trial

BACKGROUND Edoxaban, an oral factor Xa inhibitor, is non-inferior for prevention of stroke and systemic embolism in patients with atrial fibrillation and is associated with less bleeding than well controlled warfarin therapy. Few safety data about edoxaban in patients undergoing electrical cardioversion are available. METHODS We did a multicentre, prospective, randomised, open-label, blinded-endpoint evaluation trial in 19 countries with 239 sites comparing edoxaban 60 mg per day with enoxaparin-warfarin in patients undergoing electrical cardioversion of non-valvular atrial fibrillation. The dose of edoxaban was reduced to 30 mg per day if one or more factors (creatinine clearance 15-50 mL/min, low bodyweight [≤60 kg], or concomitant use of P-glycoprotein inhibitors) were present. Block randomisation (block size four)-stratified by cardioversion approach (transoesophageal echocardiography [TEE] or not), anticoagulant experience, selected edoxaban dose, and region-was done through a voice-web system. The primary efficacy endpoint was a composite of stroke, systemic embolic event, myocardial infarction, and cardiovascular mortality, analysed by intention to treat. The primary safety endpoint was major and clinically relevant non-major (CRNM) bleeding in patients who received at least one dose of study drug. Follow-up was 28 days on study drug after cardioversion plus 30 days to assess safety. This trial is registered with ClinicalTrials.gov, number NCT02072434. FINDINGS Between March 25, 2014, and Oct 28, 2015, 2199 patients were enrolled and randomly assigned to receive edoxaban (n=1095) or enoxaparin-warfarin (n=1104). The mean age was 64 years (SD 10·54) and mean CHA2DS2-VASc score was 2·6 (SD 1·4). Mean time in therapeutic range on warfarin was 70·8% (SD 27·4). The primary efficacy endpoint occurred in five (<1%) patients in the edoxaban group versus 11 (1%) in the enoxaparin-warfarin group (odds ratio [OR] 0·46, 95% CI 0·12-1·43). The primary safety endpoint occurred in 16 (1%) of 1067 patients given edoxaban versus 11 (1%) of 1082 patients given enoxaparin-warfarin (OR 1·48, 95% CI 0·64-3·55). The results were independent of the TEE-guided strategy and anticoagulation status. INTERPRETATION ENSURE-AF is the largest prospective randomised clinical trial of anticoagulation for cardioversion of patients with non-valvular atrial fibrillation. Rates of major and CRNM bleeding and thromboembolism were low in the two treatment groups. FUNDING Daiichi Sankyo provided financial support for the study.

Edoxaban for treatment of venous thromboembolism in patients with cancer: Rationale and design of the hokusai VTE-cancer study

Direct oral anticoagulants may be effective and safe for treatment of venous thromboembolism (VTE) in cancer patients, but they have not been compared with low-molecular-weight heparin (LMWH), the current recommended treatment for these patients. The Hokusai VTE-cancer study is a randomised, open-label, clinical trial to evaluate whether edoxaban, an oral factor Xa inhibitor, is non-inferior to LMWH for treatment of VTE in patients with cancer. We present the rationale and some design features of the study. One such feature is the composite primary outcome of recurrent VTE and major bleeding during a 12-month study period. These two complications occur frequently in cancer patients receiving anticoagulant treatment and have a significant impact. The evaluation beyond six months will fill the current gap in the evidence base for the long-term treatment of these patients. Based on the observation that the risk of recurrent VTE in patients with active cancer is similar to that in those with a history of cancer, the Hokusai VTE-cancer study will enrol patients if whose cancer was diagnosed within the past two years. In addition, patients with incidental VTE are eligible because their risk of recurrent VTE is similar to that in patients with symptomatic disease. The unique design features of the Hokusai VTE-cancer study should lead to enrolment of a broad spectrum of cancer patients with VTE who could benefit from oral anticoagulant treatment.

Single-dose ciraparantag safely and completely reverses anticoagulant effects of edoxaban

Summary Of the new direct oral anticoagulants, direct factor Xa inhibitors are limited by the absence of a proven reversal agent. We assessed the safety, tolerability and impact on anticoagulation reversal of ciraparantag (PER977) alone and following a 60 mg dose of the FXa inhibitor edoxaban. Escalating, single IV doses of ciraparantag were administered alone and following a 60 mg oral dose of edoxaban in a double-blind, placebo-controlled fashion to healthy subjects. Serial assessments of the pharmacokinetics and pharmacodynamic effects of ciraparantag were performed. Eighty male subjects completed the study. Following edoxaban (60 mg), a single IV dose of ciraparantag (100 to 300 mg) demonstrated full reversal of anticoagulation within 10 minutes and sustained for 24 hours. Fibrin diameter within clots was restored to normal 30 minutes after a single dose of 100 to 300 mg ciraparantag as determined by scanning electron microscopy and change in fibrin diameter quantified by automated image analysis. Potentially related adverse events were periorbital and facial flushing and cool sensation following IV injection of ciraparantag. Renal excretion of ciraparantag metabolite was the main elimination route. There was no evidence of procoagulant activity following ciraparantag as assessed by D-dimer, prothrombin fragments 1.2, and tissue factor pathway inhibitor levels. In conclusion, ciraparantag in healthy subjects is safe and well tolerated with minor, non-dose limiting adverse events. Baseline haemostasis was restored from the anticoagulated state with doses of 100 to 300 mg ciraparantag within 10–30 minutes of administration and sustained for at least 24 hours. Institution where the work was performed: Duke University Clinical Research Unit, Duke University Medical Center, Durham, NC USA

Extended duration of anticoagulation with edoxaban in patients with venous thromboembolism: a post-hoc analysis of the Hokusai-VTE study

BACKGROUND There are few data on the relative efficacy and safety of direct oral anticoagulants, such as edoxaban, compared with vitamin K antagonists during extended therapy for venous thromboembolism. This analysis evaluates the risk-benefit of extended treatment for up to 12 months with edoxaban compared with warfarin among patients enrolled in the Hokusai-VTE study who continued therapy beyond 3 months. METHODS The Hokusai-VTE trial (NCT00986154) was a randomised, double-blind, event driven non-inferiority trial in 8292 patients comparing edoxaban with warfarin in the treatment of patients with acute venous thromboembolism. All patients were treated for at least 3 months and treatment was continued for up to 12 months. The outcomes at 12 months were documented in all patients irrespective of treatment duration. 3633 patients treated with edoxaban and 3594 treated with warfarin who completed 3 months of treatment were eligible for this analysis. The primary efficacy outcome was the incidence of adjudicated symptomatic recurrent venous thromboembolism evaluated for each of the time intervals of 3 months, greater than 3 months to 6 months, greater than 6 months to less than 12 months, and at 12 months, as well as the cumulative incidence occurring between 3 and 12 months. The principal safety outcome was the incidence of clinically relevant bleeding (composite of major or clinically relevant non-major bleeding). Both on-treatment and intention-to-treat analyses were done. FINDINGS In the on-treatment analysis, the incidence of recurrent venous thromboembolism at 3 months was 1·1% (0·8-1·4; 44 of 4118 patients) in the edoxaban-treated group versus 1·2% (0·9-1·6; 51 of 4122) in the warfarin-treated group; between greater than 3 months and 6 months, 0·7% (0·3-1·5; eight of 1076) versus 0·5% (0·2-1·1; five of 1084); between greater than 6 months and less than 12 months, 0·2% (0·0-0·8; two of 896) versus 0·8% (0·03-1·7; seven of 851); and at 12 months, <0·1% (0·0-0·3; one of 1661) versus 0·1% (0·0-0·4; two of 1659). In the on-treatment analysis, the cumulative incidence of recurrent venous thromboembolism between 3 and 12 months was 0·3% (95% CI 0·2-1·5; 11 of 3633 patients) in the edoxaban-treated group and 0·4% (0·2-1·7; 14 of 3594) in the warfarin-treated group (HR 0·78, 95% CI 0·36-1·72). The cumulative incidence of clinically relevant bleeding (major or non-major) between 3 and 12 months was 3·9% (95% CI 3·3-4·6; 143 of 3633 patients) in the edoxaban-treated group and 4·1% (3·5-4·8; 147 of 3594 patients) in the warfarin-treated group (HR 0·97, 95% CI 0·77-1·22); cumulative incidence of major bleeding was 0·3% (95% CI 0·2-0·5; 11 of 3633 patients) in the edoxaban-treated group and 0·7% (0·4-1·0; 24 of 3594 patients) in the warfarin-treated group (HR 0·45, 95% CI 0·22-0·92). Similar results were obtained in the intention-to-treat analysis. INTERPRETATION Extended treatment with edoxaban is effective and associated with less major bleeding than warfarin. Edoxaban once daily provides an attractive alternative to warfarin for patients with venous thromboembolism who require extended treatment for prevention of recurrent venous thromboembolism. FUNDING Daiichi Sankyo.

Recurrent venous thromboembolism in patients with pulmonary embolism and right ventricular dysfunction: a post-hoc analysis of the Hokusai-VTE study

BACKGROUND In patients with pulmonary embolism, right ventricular dysfunction is associated with early mortality. The Hokusai-VTE study used N-terminal pro-brain natriuretic peptide (NT-proBNP) and right to left ventricular diameter ratio on CT as indicators of right ventricular dysfunction and reported that recurrent venous thromboembolism rates were lower with edoxaban than warfarin. The aim of the current study was to further explore the significance of right ventricular dysfunction and investigate potential explanations for the superiority of edoxaban-ie, differences in baseline clinical characteristics, duration of initial heparin treatment, bleeding rates, or quality of warfarin treatment. METHODS The Hokusai-VTE trial was a randomised, double-blind, event-driven non-inferiority trial in patients from centres in 37 countries that compared edoxaban with warfarin in the treatment of acute venous thromboembolism. Patients received treatment for at least 3 months and up to a maximum of 12 months. Patients were followed up for 12 months. Outcome data at 12 months was collected for all patients irrespective of treatment duration. This prespecified subgroup analysis focuses on the included patients with pulmonary embolism. The primary efficacy outcome was the incidence of adjudicated symptomatic recurrent venous thromboembolism defined as a composite of deep vein thrombosis or non-fatal or fatal pulmonary embolism at 12 months. Recurrence rates with edoxaban and warfarin were compared in patients with and without right ventricular dysfunction. In those with NT-proBNP concentrations of 500 pg/mL or higher, we compared baseline characteristics, duration of heparin treatment, and bleeding leading to study drug discontinuation in the edoxaban and warfarin groups. We also assessed quality of warfarin treatment. All analyses were done with the modified intention-to-treat population. The Hokusai-VTE trial is registered with ClinicalTrials.gov, number NCT00986154. FINDINGS Between Jan 28, 2010, and Oct 5, 2012, 8292 patients were enrolled from 439 centres, of whom 8240 received at least one dose of study drug. 3319 patients had pulmonary embolism. NT-proBNP was 500 pg/mL or higher in 465 (30%) of 1565 patients given edoxaban and in 507 (32%) of 1599 given warfarin. Recurrent venous thromboembolism occurred in 14 (3%) of 465 patients in the edoxaban group and 30 (6%) of 507 in the warfarin group (hazard ratio [HR] 0·50, 95% CI 0·26-0·94; p=0·033). The right to left ventricular diameter ratio was 0·9 or higher in 414 (44%) of 937 patients in the edoxaban group and 427 (45%) of 946 in the warfarin group. Recurrent venous thromboembolism occurred in 11 (3%) of 414 and 20 (5%) of 427 patients in the edoxaban and warfarin groups (HR 0·57, 95% CI 0·27-1·17; p=0·13). Baseline characteristics, duration of heparin treatment, and rates of bleeding leading to study drug discontinuation were similar in the edoxaban and warfarin groups and the quality of warfarin management was adequate for patients with NT-proBNP concentrations of 500 pg/mL or higher. INTERPRETATION Findings from our analysis suggest that edoxaban is more effective than warfarin in the treatment and prevention of recurrent venous thromboembolism in patients with pulmonary embolism and evidence of right ventricular dysfunction. FUNDING Daiichi Sankyo.

Clinical impact and course of major bleeding with edoxaban versus vitamin K antagonists

Edoxaban is a once-daily direct oral anticoagulant (DOAC). The Hokusai-VTE study revealed that, after initial treatment with heparin, edoxaban was non-inferior to and safer than vitamin K antagonists (VKA) in the prevention of recurrent deep-vein thrombosis and pulmonary embolism. This is the first report on the clinical relevance and management of bleeding events with edoxaban. All major bleeding events were classified blindly by three study-independent adjudicators. Pre-defined criteria were used to classify severity of clinical presentation and, separately, the clinical course and outcome into four categories. Major bleeding occurred in 56 patients treated with edoxaban and 65 patients treated with VKA. The severest categories (3 or 4) of the clinical presentation were assigned to 46 % of the major bleeding episodes in edoxaban recipients versus 58 % of the major bleeds in VKA recipients (odds ratio [OR] 0.62, 95 % confidence interval [CI] 0.30-1.27, p = 0.19). Clinical course was classified as severe (category 3 or 4) in 23 % of the edoxaban and 29 % of the VKA associated bleeds (OR 0.73, 95 % CI 0.32-1.66, p = 0.46). In conclusion, edoxaban associated major bleeding events have a comparable clinical presentation and course to major bleeds with VKA in patients treated for venous thromboembolism in the Hokusai-VTE study. These results may assure physicians that it is safe to prescribe this medication. If a major bleeding during edoxaban treatment occurs, its clinical presentation and clinical course are not worse than in VKA-treated patients.