Phase 1 Trial of Antibody NI006 for Depletion of Cardiac Transthyretin Amyloid.

BACKGROUND: Transthyretin amyloid (ATTR) cardiomyopathy is a progressive and fatal disease caused by misfolded transthyretin. Despite advances in slowing disease progression, there is no available treatment that depletes ATTR from the heart for the amelioration of cardiac dysfunction. NI006 is a recombinant human anti-ATTR antibody that was developed for the removal of ATTR by phagocytic immune cells. METHODS: In this phase 1, double-blind trial, we randomly assigned (in a 2:1 ratio) 40 patients with wild-type or variant ATTR cardiomyopathy and chronic heart failure to receive intravenous infusions of either NI006 or placebo every 4 weeks for 4 months. Patients were sequentially enrolled in six cohorts that received ascending doses (ranging from 0.3 to 60 mg per kilogram of body weight). After four infusions, patients were enrolled in an open-label extension phase in which they received eight infusions of NI006 with stepwise increases in the dose. The safety and pharmacokinetic profiles of NI006 were assessed, and cardiac imaging studies were performed. RESULTS: The use of NI006 was associated with no apparent drug-related serious adverse events. The pharmacokinetic profile of NI006 was consistent with that of an IgG antibody, and no antidrug antibodies were detected. At doses of at least 10 mg per kilogram, cardiac tracer uptake on scintigraphy and extracellular volume on cardiac magnetic resonance imaging, both of which are imaging-based surrogate markers of cardiac amyloid load, appeared to be reduced over a period of 12 months. The median N-terminal pro-B-type natriuretic peptide and troponin T levels also seemed to be reduced. CONCLUSIONS: In this phase 1 trial of the recombinant human antibody NI006 for the treatment of patients with ATTR cardiomyopathy and heart failure, the use of NI006 was associated with no apparent drug-related serious adverse events. (Funded by Neurimmune; NI006-101 ClinicalTrials.gov number, NCT04360434.).

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 warfarin in patients with atrial fibrillation in relation to the risk of stroke: A secondary analysis of the ENGAGE AF-TIMI 48 study.

INTRODUCTION: The efficacy and safety of the oral factor Xa inhibitor edoxaban compared to warfarin stratified by CHA2DS2VASc scores have not been described. METHODS: The ENGAGE AF-TIMI 48 trial randomized patients with atrial fibrillation to once-daily edoxaban or warfarin. We classified patients based on CHA2DS2VASc score and compared pharmacokinetics (edoxaban concentration), pharmacodynamics (anti-factor Xa [FXa] with edoxaban, time-in-therapeutic range for warfarin), efficacy (stroke or systemic embolism [SSE]), safety (major bleeding [MB], intracranial hemorrhage), and cardiovascular mortality, for the approved edoxaban regimen vs warfarin. RESULTS: The distribution CHA2DS2VASc score were:≤3, N = 4159 (29.6%); 4, N = 4066 (28.9%); 5, N = 3165 (22.5%); and ≥6, N = 2681 (19.1%). Increasing rates of SSE (1.05 to 2.99%/year) and MB (2.27 to 4.66%/year) were observed in the warfarin arm as the CHA2DS2VASc score increased. The hazard ratios per unit increase of CHA2DS2VASc score were 1.29 (1.21-1.38) and 1.26 (1.17-1.36) for SSE, and 1.20 (1.13-1.27) and 1.19 (1.12-1.27) for MB, with warfarin and edoxaban, respectively. Time-in-therapeutic range in warfarin-treated patients was similar and high (median 68%-69%) across CHA2DS2VASc scores, whereas edoxaban trough concentration, exogenous anti-FXa activity and %inhibition of endogenous FXa were higher at increasing CHA2DS2VASc scores. Edoxaban reduced SSE, MB, intracranial hemorrhage, and cardiovascular mortality vs warfarin to a similar degree across the range of CHA2DS2VASc scores (P-int = 0.90, 0.96, 0.21, and 0.37, respectively). Because of higher event rates the number of events prevented with edoxaban tended to be greater in patients with higher CHA2DS2VASc scores. CONCLUSION: The benefit and safety of edoxaban versus warfarin is maintained across CHA2DS2VASc scores. While the relative risk reductions remain similar, edoxaban provides incrementally larger absolute reductions in outcomes over warfarin in patients with higher CHA2DS2VASc scores.

Comparison of Events Across Bleeding Scales in the ENGAGE AF-TIMI 48 Trial.

BACKGROUND: Numerous scales exist for the classification of major bleeding events. Limited data compare the most commonly used bleeding scales within a single at-risk cohort of patients with atrial fibrillation. Here, we analyze bleeding outcomes according to the ISTH (International Society on Thrombosis and Hemostasis), TIMI (Thrombolysis in Myocardial Infarction), GUSTO (Global Usage of Strategies to Open Occluded Arteries), and BARC (Bleeding Academic Research Consortium) bleeding scales in the ENGAGE AF (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation)-TIMI 48 trial (NCT00781391) of edoxaban versus warfarin. METHODS: A total of 21 105 patients with atrial fibrillation at risk for stroke (CHADS2 score ≥2) were enrolled in the ENGAGE AF-TIMI 48 trial comparing warfarin with a higher- (60/30 mg daily) or lower- (30/15 mg daily) dose edoxaban regimen. Median follow-up was 2.8 years. Bleeding events occurring among on-treatment patients were examined. Annualized event rates were calculated by the ISTH, TIMI, GUSTO, and BARC scales and compared across treatment arms. Cox proportional hazards for a first bleeding event of each type were calculated for higher-dose edoxaban regimen vs warfarin and lower-dose edoxaban regimen versus warfarin. RESULTS: A total of 10 311 bleeding events were reported. In a comparison of the most severe events in each scale, ISTH major bleeding was the most common (n=1289), followed by TIMI major (n=548), GUSTO severe/life-threatening (n=347), and BARC 3c+5 (n=276) bleeding. Lower bleeding risk with edoxaban compared with warfarin was seen regardless of bleeding scale (higher-dose edoxaban regimen range: hazard ratio [HR], 0.47 [95% CI, 0.35-0.62] for BARC 3c+5 versus HR, 0.80 [95% CI, 0.71-0.91] for ISTH major; lower-dose edoxaban regimen range: HR, 0.32 [95% CI, 0.23-0.45] for BARC 3c+5 versus HR, 0.47 [95% CI, 0.41-0.55] for ISTH major). Furthermore, a gradient of more pronounced risk reduction with edoxaban was observed with greater severity of first bleeding event (higher-dose edoxaban regimen: HR, 0.47 [95% CI, 0.35-0.62] for BARC 3c+5 bleeds versus HR, 0.86 [95% CI, 0.81-0.91] for any BARC bleed; lower-dose edoxaban regimen: HR, 0.32 [95% CI, 0.23-0.45] for BARC 3c+5 bleeds versus HR, 0.68 [95% CI, 0.63-0.72] for any BARC bleed). The direction of this trend was consistent for both gastrointestinal bleeding and nongastrointestinal bleeding. CONCLUSIONS: Among patients with atrial fibrillation at risk for stroke, there was a >4-fold difference in the frequency of the most severe bleeding events across commonly used bleeding scales. Furthermore, the relative safety of edoxaban compared with warfarin tended to increase with greater severity of bleeding. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00781391.

Performance of the ABC Scores for Assessing the Risk of Stroke or Systemic Embolism and Bleeding in Patients With Atrial Fibrillation in ENGAGE AF-TIMI 48.

BACKGROUND: The ABC (age, biomarker, clinical history)-stroke and ABC-bleeding risk scores incorporate clinical variables and cardiovascular biomarkers to estimate risk of stroke or systemic embolic events and bleeding, respectively, in patients with atrial fibrillation. These scores have been proposed for routine clinical use, but their performance in external cohorts remains uncertain. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a multinational randomized trial of the oral factor Xa inhibitor edoxaban in patients with atrial fibrillation and a CHADS2 score ≥2. We performed a nested prospective biomarker study in 8705 patients, analyzing baseline high-sensitivity troponin T (hsTnT), NT-proBNP (N-terminal B-type natriuretic peptide), and growth differentiation factor-15 (GDF-15), as well as in serial samples after 12 months. The ABC-stroke (age, prior stroke/transient ischemic attack, hsTnT, NT-proBNP) and ABC-bleeding (age, prior bleeding, hemoglobin, hsTnT, and GDF-15) scores were tested. Hazard ratios were adjusted for estimated glomerular filtration rate and the components of the CHA2DS2-VASc and HAS-BLED scores, respectively. Discrimination and reclassification were compared with these established scores. RESULTS: Median baseline hsTnT, NT-proBNP, and GDF-15 levels were 13.7 ng/L (25th-75th percentiles, 9.6-20.4 ng/L), 811 pg/mL (386-1436 pg/mL), and 1661 pg/mL (1179-2427 pg/mL), respectively. Elevated hsTnT, NT-proBNP, and GDF-15 were independently associated with higher rates of stroke or systemic embolic events, and elevated hsTnT and GDF-15 were independently associated with higher rates of major bleeding ( P<0.001 for each). The ABC-stroke and ABC-bleeding scores were well calibrated and yielded higher c indexes than the CHA2DS2-VASc score for stroke or systemic embolic events (0.67 [95% CI, 0.65-0.70] versus 0.59 [95% CI, 0.57-0.62]; P<0.001) and HAS-BLED score for major bleeding (0.69 [95% CI, 0.66-0.71] versus 0.62 [95% CI, 0.60-0.64]; P<0.001), respectively. The ABC-stroke and ABC-bleeding scores stratified patients within CHA2DS2-VASc and HAS-BLED risk categories ( P<0.001 for both). Patients with ABC-bleeding scores predicting a high 1-year risk of bleeding (>2%) derived greater benefit from treatment with edoxaban compared with warfarin. CONCLUSIONS: The ABC-stroke and ABC-bleeding scores evaluated in this anticoagulated clinical trial cohort were well calibrated and outperformed the CHA2DS2-VASc and HAS-BLED scores, respectively. These scores may help identify patients most likely to derive a benefit from treatment with non-vitamin K antagonist oral anticoagulants. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00781391.

Relationship between body mass index and outcomes in patients with atrial fibrillation treated with edoxaban or warfarin in the ENGAGE AF-TIMI 48 trial.

AIMS: To investigate the relationship between body mass index (BMI) and outcomes in patients with atrial fibrillation (AF). METHODS AND RESULTS: In the ENGAGE AF-TIMI 48 trial, patients with AF were randomized to warfarin (international normalized ratio 2.0-3.0) or edoxaban. The cohort (N = 21 028) included patients across BMI categories (kg/m2): underweight (<18.5) in 0.8%, normal (18.5 to <25) in 21.4%, overweight (25 to <30) in 37.6%, moderately obese (30 to <35) in 24.8%, severely obese (35 to <40) in 10.0%, and very severely obese (≥40) in 5.5%. In an adjusted analysis, higher BMI (continuous, per 5 kg/m2 increase) was significantly and independently associated with lower risks of stroke/systemic embolic event (SEE) [hazard ratio (HR) 0.88, P = 0.0001], ischaemic stroke/SEE (HR 0.87, P < 0.0001), and death (HR 0.91, P < 0.0001), but with increased risks of major (HR 1.06, P = 0.025) and major or clinically relevant non-major bleeding (HR 1.05, P = 0.0007). There was a significant interaction between sex and increasing BMI category, with lower risk of ischaemic stroke/SEE in males and increased risk of bleeding in women. Trough edoxaban concentration and anti-Factor Xa activity were similar across BMI groups >18.5 kg/m2, while time in therapeutic range for warfarin improved significantly as BMI increased (P < 0.0001). The effects of edoxaban vs. warfarin on stroke/SEE, major bleeding, and net clinical outcome were similar across BMI groups. CONCLUSION: An increased BMI was independently associated with a lower risk of stroke/SEE, better survival, but increased risk of bleeding. The efficacy and safety profiles of edoxaban were similar across BMI categories ranging from 18.5 to >40.

Clinical outcomes, edoxaban concentration, and anti-factor Xa activity of Asian patients with atrial fibrillation compared with non-Asians in the ENGAGE AF-TIMI 48 trial.

AIMS: Prior studies suggested that the risks of ischaemic stroke and bleeding in patients of Asian race with atrial fibrillation (AF) may be higher than that of non-Asians. In the analysis of ENGAGE AF-TIMI 48 trial, we compared clinical outcomes, edoxaban concentration, and anti-factor Xa (anti-FXa) activity, between Asian and non-Asian races. METHODS AND RESULTS: There were 2909 patients of Asian race and 18 195 non-Asian race in the ENGAGE AF-TIMI 48 trial. The risks of thromboembolism and bleeding events were compared for Asians and non-Asians treated with warfarin. The trough levels of edoxaban concentration and anti-FXa activity were also compared and correlated with the efficacy and safety of edoxaban vs. warfarin. Compared to non-Asian patients, the Asian population was on average 2 years younger and 20 kg lighter. In the warfarin group, the adjusted risk of ischaemic stroke did not differ significantly for patients of Asian and non-Asian race [adjusted hazard ratio (aHR) = 1.12, P = 0.56). Asians treated with warfarin had a higher-adjusted risk of intracranial haemorrhage (ICH: aHR 1.71, P = 0.03) compared with non-Asians. The trough edoxaban concentration and anti-FXa activity were 20-25% lower for Asians compared with non-Asians. Compared to warfarin, higher dose edoxaban significantly reduced ICH while preserving the efficacy of stroke prevention in both Asians and non-Asians. Two of three net clinical outcomes appeared to be more favourably reduced with edoxaban in Asians compared with non-Asians (Pint = 0.063 for primary, 0.037 for secondary, and 0.032 for third net clinical outcomes, respectively). CONCLUSION: Compared to warfarin, higher dose edoxaban preserved the efficacy for stroke prevention and was associated with a favourable safety profile for Asians, which may be due to the lower trough edoxaban concentration and anti-FXa activity achieved in patients of Asian race.

Linking Endogenous Factor Xa Activity, a Biologically Relevant Pharmacodynamic Marker, to Edoxaban Plasma Concentrations and Clinical Outcomes in the ENGAGE AF-TIMI 48 Trial.

BACKGROUND: We previously reported exogenous antifactor Xa (FXa) activity as a pharmacokinetic surrogate marker for edoxaban plasma concentrations. Inhibition of endogenous FXa activity is a more biologically relevant pharmacodynamic measure of edoxaban activity. Here we describe the value of endogenous FXa activity as a pharmacodynamic marker linking edoxaban concentrations and clinical outcomes in the ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction Study 48). METHODS: In ENGAGE AF-TIMI 48, edoxaban was administered in higher dose (60/30 mg QD) and lower dose (30/15 mg QD) regimens. Both regimens incorporated a 50% dose reduction in patients with characteristics known to increase edoxaban concentration. Pharmacokinetic-pharmacodynamic modeling was performed in a subgroup of 3029 patients who had samples collected for endogenous FXa activity (measured using an assay after endogenous FX was activated with Russell viper venom). RESULTS: Endogenous FXa activity decreased with increasing edoxaban concentrations of ≤440 ng/mL, indicating that inhibition of endogenous FXa activity is saturated above this concentration threshold. Baseline endogenous FXa activity averaged 92.1±20.9% (relative to normal control samples) and was lower with older age, with lower body weight, and in male patients. Model-predicted 24-hour average percentages of inhibition of endogenous FXa activity were 35.8±5.18, 29.1±3.92, 21.9±3.80, and 16.4±2.70 for the higher dose edoxaban regimen 60 mg, dose-reduced higher dose edoxaban regimen 30 mg, lower dose edoxaban regimen 30 mg, and dose-reduced lower dose edoxaban regimen 15 mg groups, respectively. A greater average percentage of inhibition of endogenous FXa activity was associated with a lower incidence of ischemic stroke or systemic embolism and a higher risk of major bleeding ( P<0.001). In a typical subject, the predicted risks for the 10th and 90th percentiles of inhibition of endogenous FXa activity were 1.04% and 0.57% for incidence of ischemic stroke or systemic embolism and 1.35% and 2.33% for major bleeding, respectively. CONCLUSIONS: The extent of inhibition of endogenous FXa activity is influenced by edoxaban dosing and clinical characteristics, and it is associated with both antithrombotic benefit and risk of bleeding. This approach of linking endogenous FXa activity to clinical outcomes may be used to guide dose selection in future clinical trials, monitor patients in certain clinical scenarios, or refine the doses of oral FXa inhibitors in patients who require precise anticoagulation therapy. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00781391.

Edoxaban and implantable cardiac device interventions: insights from the ENGAGE AF-TIMI 48 trial.

AIMS: Pacemaker, implantable cardioverter-defibrillator, and cardiac resynchronization therapy device implantations and generator changes are frequently performed in patients receiving direct oral anticoagulants. In an exploratory analysis, we investigated the outcome of patients undergoing such device procedures in the ENGAGE AF-TIMI 48 trial. METHODS AND RESULTS: During the trial, 1217 device procedures were performed in 1145 patients, with intervention dates available for 1203 procedures. Two hundred and twenty-five procedures (in 212 patients) were performed >30 days after study drug was stopped and are not included in the event analysis. For most interventions (n = 728, 74%), study drug was interrupted >3 days (median for the entire cohort: 5 days, interquartile range 0-11 days); 250 interventions were performed with ≤3 days study drug interruption. During the first 30 days after the procedure, six strokes/systemic embolic events (SEEs) (three each in the lower-dose edoxaban and warfarin arm) and one major bleeding event (in the lower-dose edoxaban arm) occurred; no stroke/SEEs or major bleeds occurred around the 295 device procedures in the higher-dose edoxaban arm. Two ischaemic and one major bleeding event occurred after the 288 device procedures performed with ≤3 days periprocedural interruption of study drug. CONCLUSION: In this first experience of patients undergoing device surgery with edoxaban, a low risk of ischaemic and bleeding events was observed during the first 30 days post-procedure. Our data are in line with current recommendations of no or only brief interruption of non-vitamin K antagonist oral anticoagulants prior to cardiac device surgery.

A novel risk prediction score in atrial fibrillation for a net clinical outcome from the ENGAGE AF-TIMI 48 randomized clinical trial.

AIMS: The choice between initiating a non-vitamin K antagonist oral anticoagulant (NOAC) and a vitamin K antagonist (VKA) in patients with atrial fibrillation (AF) may be challenging. To assist in this decision, we developed a risk score to identify patients for whom a therapeutic benefit of NOACs over VKA is predicted. METHODS AND RESULTS: ENGAGE AF-TIMI 48 was a randomized clinical trial of edoxaban vs. warfarin in 21 105 patients with AF. Cox proportional hazard models identified factors associated with a serious net clinical outcome (NCO) of disabling stroke, life-threatening bleeding, and all-cause mortality in VKA naïve patients from the warfarin arm. These were used to develop an integer risk score. Performance was assessed by C-indices and validation by bootstrapping. Kaplan-Meier analyses were stratified by three score categories and treatment arm. Over a median of 2.7 years, 457 NCO events occurred in 2898 patients with a total person-time of 7549.5 years (6.05%/year). The risk prediction model (C = 0.693) for the NCO was translated into a 17-point integer score, with annualized event rates for the low, intermediate, and high-risk categories in the warfarin arm of 3.5%, 9.9%, and 20.8%, respectively. Therapeutic benefit of higher- and lower-dose edoxaban over warfarin was demonstrated in the high- and intermediate-risk, with equal benefit in the low-risk categories (P-interaction 0.008 and 0.014, respectively). CONCLUSION: In VKA naive patients with AF, the TIMI-AF score can assist in the prediction of a poor composite outcome and guide selection of anticoagulant therapy by identifying a differential clinical benefit with a NOAC or VKA.

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.

Outcomes With Edoxaban Versus Warfarin in Patients With Previous Cerebrovascular Events: Findings From ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48).

BACKGROUND AND PURPOSE: Patients with atrial fibrillation and previous ischemic stroke (IS)/transient ischemic attack (TIA) are at high risk of recurrent cerebrovascular events despite anticoagulation. In this prespecified subgroup analysis, we compared warfarin with edoxaban in patients with versus without previous IS/TIA. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind trial of 21 105 patients with atrial fibrillation randomized to warfarin (international normalized ratio, 2.0-3.0; median time-in-therapeutic range, 68.4%) versus once-daily edoxaban (higher-dose edoxaban regimen [HDER], 60/30 mg; lower-dose edoxaban regimen, 30/15 mg) with 2.8-year median follow-up. Primary end points included all stroke/systemic embolic events (efficacy) and major bleeding (safety). Because only HDER is approved, we focused on the comparison of HDER versus warfarin. RESULTS: Of 5973 (28.3%) patients with previous IS/TIA, 67% had CHADS2 (congestive heart failure, hypertension, age, diabetes, prior stroke/transient ischemic attack) >3 and 36% were ≥75 years. Compared with 15 132 without previous IS/TIA, patients with previous IS/TIA were at higher risk of both thromboembolism and bleeding (stroke/systemic embolic events 2.83% versus 1.42% per year; P<0.001; major bleeding 3.03% versus 2.64% per year; P<0.001; intracranial hemorrhage, 0.70% versus 0.40% per year; P<0.001). Among patients with previous IS/TIA, annualized intracranial hemorrhage rates were lower with HDER than with warfarin (0.62% versus 1.09%; absolute risk difference, 47 [8-85] per 10 000 patient-years; hazard ratio, 0.57; 95% confidence interval, 0.36-0.92; P=0.02). No treatment subgroup interactions were found for primary efficacy (P=0.86) or for intracranial hemorrhage (P=0.28). CONCLUSIONS: Patients with atrial fibrillation with previous IS/TIA are at high risk of recurrent thromboembolism and bleeding. HDER is at least as effective and is safer than warfarin, regardless of the presence or the absence of previous IS or TIA. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781391.

Genetics and the clinical response to warfarin and edoxaban: findings from the randomised, double-blind ENGAGE AF-TIMI 48 trial.

BACKGROUND: Warfarin is the most widely used oral anticoagulant worldwide, but serious bleeding complications are common. We tested whether genetic variants can identify patients who are at increased risk of bleeding with warfarin and, consequently, those who would derive a greater safety benefit with a direct oral anticoagulant rather than warfarin. METHODS: ENGAGE AF-TIMI 48 was a randomised, double-blind trial in which patients with atrial fibrillation were assigned to warfarin to achieve a target international normalised ratio of 2·0-3·0, or to higher-dose (60 mg) or lower-dose (30 mg) edoxaban once daily. A subgroup of patients was included in a prespecified genetic analysis and genotyped for variants in CYP2C9 and VKORC1. The results were used to create three genotype functional bins (normal, sensitive, and highly sensitive responders to warfarin). This trial is registered with ClinicalTrials.gov, number NCT00781391. FINDINGS: 14,348 patients were included in the genetic analysis. Of 4833 taking warfarin, 2982 (61·7%) were classified as normal responders, 1711 (35·4%) as sensitive responders, and 140 (2·9%) as highly sensitive responders. Compared with normal responders, sensitive and highly sensitive responders spent greater proportions of time over-anticoagulated in the first 90 days of treatment (median 2·2%, IQR 0-20·2; 8·4%, 0-25·8; and 18·3%, 0-32·6; ptrend<0·0001) and had increased risks of bleeding with warfarin (sensitive responders hazard ratio 1·31, 95% CI 1·05-1·64, p=0·0179; highly sensitive responders 2·66, 1·69-4·19, p<0·0001). Genotype added independent information beyond clinical risk scoring. During the first 90 days, when compared with warfarin, treatment with edoxaban reduced bleeding more so in sensitive and highly sensitive responders than in normal responders (higher-dose edoxaban pinteraction=0·0066; lower-dose edoxaban pinteraction=0·0036). After 90 days, the reduction in bleeding risk with edoxaban versus warfarin was similarly beneficial across genotypes. INTERPRETATION: CYP2C9 and VKORC1 genotypes identify patients who are more likely to experience early bleeding with warfarin and who derive a greater early safety benefit from edoxaban compared with warfarin. FUNDING: Daiichi Sankyo.

Edoxaban vs warfarin in patients with nonvalvular atrial fibrillation in the US Food and Drug Administration approval population: An analysis from the Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48 (ENGAGE AF-TIMI 48) trial.

BACKGROUND: Edoxaban is a specific anti-Xa inhibitor that, in comparison to warfarin, has been found to be noninferior for the prevention of stroke or systemic embolism (SSE) and to reduce bleeding significantly in patients with nonvalvular atrial fibrillation (AF). The US Food and Drug Administration (FDA) approved the higher-dose edoxaban regimen (60/30 mg) in patients with AF and a creatinine clearance of ≤95 mL/min. We report for the first time the clinical characteristics, efficacy, and safety of the FDA-approved population in the ENGAGE AF--TIMI 48 trial. METHODS: The patients included had been treated with either warfarin or edoxaban 60/30 mg and had a creatinine clearance of ≤95 mL/min. The primary efficacy was SSE, and the principal safety end point was major bleeding (International Society on Thrombosis and Haemostasis classification). Median follow-up was 2.8 years. RESULTS: Patients in the FDA-approved cohort were older, were more likely female, and had higher CHADS2 and HAS-BLED scores, as compared with patients not included in the FDA label. The primary end point occurred in 1.63%/y with edoxaban vs 2.02%/y with warfarin (hazard ratio [HR] 0.81, 95% CI 0.67-0.97, P = .023). Edoxaban significantly reduced the rate of hemorrhagic stroke (HR 0.47, 95% CI 0.31-0.72, P < .001) and cardiovascular death (HR 0.84, 95% CI 0.73-0.97, P = .015). Ischemic stroke rates were similar between the treatment groups (1.31%/y vs 1.39%/y, P = .97). Major bleeding was significantly lower with edoxaban (3.16%/y vs 3.77%/y; HR 0.84, 95% CI 0.72-0.98, P = .023). CONCLUSION: In the FDA-approved cohort of the ENGAGE AF--TIMI 48 trial, treatment with edoxaban 60/30 mg was superior to warfarin in the prevention of SSE and significantly reduced cardiovascular death and bleeding, especially fatal bleeding and hemorrhagic stroke.

Nonvitamin K antagonist oral anticoagulant activity: challenges in measurement and reversal.

BACKGROUND: Four nonvitamin K antagonist oral anticoagulants (NOACs) are approved for the prevention of stroke in patients with nonvalvular atrial fibrillation and for the treatment of venous thromboembolism. These include the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban, apixaban, and edoxaban. Bleeding is a complication for all anticoagulants and concerns regarding bleeding risk and the suitability of effective reversal strategies may be a barrier to their prescription. Despite the reduced risk of bleeding compared with vitamin K antagonists, questions persist regarding the management of bleeding related to NOAC use. MAIN TEXT: To date, although a number of assays are responsive to NOACs, no single routine laboratory test has been identified to accurately measure the clinical anticoagulation state of patients on NOACs or established as a reliable predictor of bleeding risk. In addition, the establishment of a reliable human bleeding model to test novel inhibitors of the coagulation cascade has proved challenging. Although routine monitoring of anticoagulant levels is not necessary in patients taking NOACs, anticoagulant reversal and a means of measuring reversal may be required for patients who present with bleeding or require urgent surgery. Prothrombin complex concentrates are pooled plasma products containing varying amounts of inactive vitamin K-dependent clotting factors in addition to vitamin K-dependent proteins and can replenish factors in the intrinsic and extrinsic coagulation cascade, reversing an anticoagulant effect. Only one agent, idarucizumab, has been approved for rapid reversal of dabigatran-induced anticoagulation and one more agent, andexanet alfa, has been submitted for approval to reverse the anticoagulatory effects of direct and indirect factor Xa inhibitors. CONCLUSIONS: This review discusses the laboratory tests available for assessing anticoagulation, human models of bleeding, and the use of current strategies-including prothrombin complex concentrates for reversal of anticoagulation by NOACs-to manage bleeding in patients.

Edoxaban vs. warfarin in vitamin K antagonist experienced and naive patients with atrial fibrillation†.

AIMS: Edoxaban is an oral, once-daily factor Xa inhibitor that is non-inferior to well-managed warfarin in patients with atrial fibrillation (AF) for the prevention of stroke and systemic embolic events (SEEs). We examined the efficacy and safety of edoxaban vs. warfarin in patients who were vitamin K antagonist (VKA) naive or experienced. METHODS AND RESULTS: ENGAGE AF-TIMI 48 randomized 21 105 patients with AF at moderate-to-high risk of stroke to once-daily edoxaban vs. warfarin. Subjects were followed for a median of 2.8 years. The primary efficacy endpoint was stroke or SEE. As a pre-specified subgroup, we analysed outcomes for those with or without prior VKA experience (>60 consecutive days). Higher-dose edoxaban significantly reduced the risk of stroke or SEE in patients who were VKA naive [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.56-0.90] and was similar to warfarin in the VKA experienced (HR 1.01, 95% CI 0.82-1.24; P interaction = 0.028). Lower-dose edoxaban was similar to warfarin for stroke or SEE prevention in patients who were VKA naive (HR 0.92, 95% CI 0.73-1.15), but was inferior to warfarin in those who were VKA experienced (HR 1.31, 95% 1.08-1.60; P interaction = 0.019). Both higher-dose and lower-dose edoxaban regimens significantly reduced the risk of major bleeding regardless of prior VKA experience (P interaction = 0.90 and 0.71, respectively). CONCLUSION: In patients with AF, edoxaban appeared to demonstrate greater efficacy compared with warfarin in patients who were VKA naive than VKA experienced. Edoxaban significantly reduced major bleeding compared with warfarin regardless of prior VKA exposure.

Application of the Win Ratio Method in the ENGAGE AF-TIMI 48 Trial Comparing Edoxaban With Warfarin in Patients With Atrial Fibrillation.

BACKGROUND: Cardiovascular trials often use a composite end point and a time-to-first event model. We sought to compare edoxaban versus warfarin using the win ratio, which offers data complementary to time-to-first event analysis, emphasizing the most severe clinical events. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind, randomized trial in which patients with atrial fibrillation were assigned 1:1:1 to a higher dose edoxaban regimen (60/30 mg daily), a lower dose edoxaban regimen (30/15 mg daily), or warfarin. In an exploratory analysis, we analyzed the trial outcomes using an unmatched win ratio approach. The win ratio for each edoxaban regimen was the total number of edoxaban wins divided by the number of warfarin wins for the following ranked clinical outcomes: 1: death; 2: hemorrhagic stroke; 3: ischemic stroke/systemic embolic event/epidural or subdural bleeding; 4: noncerebral International Society on Thrombosis and Haemostasis major bleeding; and 5: cardiovascular hospitalization. RESULTS: 21 105 patients were randomized to higher dose edoxaban regimen (N=7035), lower dose edoxaban regimen (N=7034), or warfarin (N=7046), yielding >49 million pairs for each treatment comparison. The median age was 72 years, 38% were women, and 59% had prior vitamin K antagonist use. The win ratio was 1.11 (95% CI, 1.05-1.18) for higher dose edoxaban regimen versus warfarin and 1.11 (95% CI, 1.05-1.18) for lower dose edoxaban regimen versus warfarin. The favorable impacts of edoxaban on death (34% of wins) and cardiovascular hospitalization (41% of wins) were the major contributors to the win ratio. Results consistently favored edoxaban in subgroups based on creatine clearance and dose reduction at baseline, with heightened benefit among those without prior vitamin K antagonist use. CONCLUSIONS: In a win ratio analysis of the ENGAGE AF-TIMI 48 trial, both dose regimens of edoxaban were superior to warfarin for the net clinical outcome incorporating ischemic and bleeding events. As the win ratio emphasizes the most severe clinical events, this analysis supports the superiority of edoxaban over warfarin in patients with atrial fibrillation. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00781391.

Pharmacogenetic-guided and clinical warfarin dosing algorithm assessments with bleeding outcomes risk-stratified by genetic and covariate subgroups.

BACKGROUND: Safe administration of warfarin presents challenges due to a narrow therapeutic INR range and significant variability in inter-individual dose response. Bleeding secondary to warfarin use is a leading cause of hospitalization. METHODS: Five warfarin dosing algorithms were assessed for accuracy of predicted compared to the INR target dose for patients with a HAS-BLED score ≥3 participating in the ENGAGE-AF TIMI 48 trial. Three warfarin metabolism subgroups (normal, sensitive, and highly sensitive responders) were established based on genotype. Mean differences between calculated and prescribed dose were determined for each algorithm across groups. RESULTS: A total of 7036 patients were analyzed and 1846 participants with HAS-BLED ≥3 were genotyped. The mean absolute error of predicted versus INR target dose for warfarin ranged from 8.1 mg/week on the pharmacogenetic-guided International Warfarin Pharmacogenetics Consortium (IWPC) and Gage algorithms to 11.3 mg/week on fixed dose. Overestimation of INR target dose occurred in 98% of highly sensitive responders by 21 mg/week for subjects on fixed dose. Pharmacogenetic-guided IWPC saw 89% overestimation with mean difference of 8.3 mg/week for highly sensitive responders. Major or clinically relevant non-major bleeding in the first 90 days of beginning warfarin was 3.27 times more likely for highly sensitive than normal responders. CONCLUSIONS: Initial doses were higher than INR target doses in high-risk bleeding subpopulations as defined by the modified HAS-BLED and genotype sensitivity analysis when compared to established algorithms. Clinical and pharmacogenetic-guided algorithms improved dosing in highly sensitive responders with HAS-BLED ≥3 compared to fixed dosing.