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Anticoagulant treatment of pediatric cancer–associated venous thromboembolism (VTE) has not been prospectively evaluated. Management of anticoagulation for cancer-associated VTE is often challenged by drug interactions and treatment interruptions. A total of 56 of the 500 children (11.2%) with VTE who participated in the recent EINSTEIN-Jr randomized study had cancer (hematologic malignancy, 64.3%, solid malignant tumor, 35.7%). Children were allocated to either therapeutic-dose bodyweight-adjusted oral rivaroxaban (n=40) or standard anticoagulation with heparins, with or without vitamin K antagonists (n=16) and received a median of 30 concomitant medications. Based on sparse blood sampling at steady-state, pharmacokinetic (PK) parameters of rivaroxaban were derived using population PK modeling. During the 3 months of treatment, no recurrent VTE or major bleeding occurred (95% confidence interval, 0.0%-6.4%), and 3-month repeat imaging showed complete or partial vein recanalization in 20 and 24 of 52 evaluable children (38.5% and 46.2%, respectively). Anticoagulant treatment was interrupted 70 times in 26 (46.4%) children because of thrombocytopenia, invasive procedures, or adverse events, for a mean individual period of 5.8 days. Anticoagulant therapy was resumed in therapeutic doses and was not associated with thrombotic or bleeding complications. Rivaroxaban exposures were within the adult exposure range and similar to those observed in children with VTE who did not have cancer-associated VTE. Rivaroxaban and standard anticoagulants appeared safe and efficacious and were associated with reduced clot burden in most children with cancer-associated VTE, including those who had anticoagulant treatment interruptions. Rivaroxaban exposures were within the adult exposure range despite significant polypharmacy use. This trial was registered at www.clinicaltrials.gov as #NCT02234843.

Rivaroxaban has been investigated in the EINSTEIN‐Jr program for the treatment of acute venous thromboembolism (VTE) in children aged 0 to 18 years and in the UNIVERSE program for thromboprophylaxis in children aged 2 to 8 years with congenital heart disease after Fontan‐procedure. Physiologically‐based pharmacokinetic (PBPK) and population pharmacokinetic (PopPK) modeling were used throughout the pediatric development of rivaroxaban according to the learn‐and‐confirm paradigm. The development strategy was to match pediatric drug exposures to adult exposure proven to be safe and efficacious. In this analysis, a refined pediatric PopPK model for rivaroxaban based on integrated EINSTEIN‐Jr data and interim PK data from part A of the UNIVERSE phase III study was developed and the influence of potential covariates and intrinsic factors on rivaroxaban exposure was assessed. The model adequately described the observed pediatric PK data. PK parameters and exposure metrics estimated by the PopPK model were compared to the predictions from a previously published pediatric PBPK model for rivaroxaban. Ninety‐one percent of the individual post hoc clearance estimates were found within the 5th to 95th percentile of the PBPK model predictions. In patients below 2 years of age, however, clearance was underpredicted by the PBPK model. The iterative and integrative use of PBPK and PopPK modeling and simulation played a major role in the establishment of the bodyweight‐adjusted rivaroxaban dosing regimen that was ultimately confirmed to be a safe and efficacious dosing regimen for children aged 0 to 18 years with acute VTE in the EINSTEIN‐Jr phase III study.

IONIS‐FXIRX (BAY2306001) is an antisense oligonucleotide that inhibits the synthesis of coagulation factor XI (FXI) and has been investigated in healthy volunteers and patients with end‐stage renal disease (ESRD). FXI‐LICA (BAY2976217) shares the same RNA sequence as IONIS‐FXIRX but contains a GalNAc‐conjugation that facilitates asialoglycoprotein receptor (ASGPR)‐mediated uptake into hepatocytes. FXI‐LICA has been studied in healthy volunteers and is currently investigated in patients with ESRD on hemodialysis. We present a model‐informed bridging approach that facilitates the extrapolation of the dose‐exposure‐FXI relationship from IONIS‐FXIRX to FXI‐LICA in patients with ESRD and, thus, supports the selection of FX‐LICA doses being investigated in patients with ESRD. A two‐compartment pharmacokinetic (PK) model, with mixed first‐ and zero‐order subcutaneous absorption and first‐order elimination, was combined with an indirect response model for the inhibitory effect on the FXI synthesis rate via an effect compartment. This PK/pharmacodynamic model adequately described the median trends, as well as the interindividual variabilities for plasma drug concentration and FXI activity in healthy volunteers of IONIS‐FXIRX and FXI‐LICA, and in patients with ESRD of IONIS‐FXIRX. The model was then used to predict dose‐dependent steady‐state FXI activity following repeat once‐monthly doses of FXI‐LICA in a virtual ESRD patient population. Under the assumption of similar ASGPR expression in patients with ESRD and healthy volunteers, doses of 40 mg, 80 mg, and 120 mg FXI‐LICA are expected to cover the target range of clinical interest for steady‐state FXI activity in the phase IIb study of FXI‐LICA in patients with ESRD undergoing hemodialysis.

Anticoagulant treatment of pediatric cerebral venous thrombosis has not been evaluated in randomized trials. We evaluated the safety and efficacy of rivaroxaban and standard anticoagulants in the predefined subgroup of children with cerebral venous thrombosis (CVT) who participated in the EINSTEIN-Jr trial. Children with CVT were randomized (2:1), after initial heparinization, to treatment with rivaroxaban or standard anticoagulants (continued on heparin or switched to vitamin K antagonist). The main treatment period was 3 months. The primary efficacy outcome, symptomatic recurrent venous thromboembolism (VTE), and principal safety outcome, major or clinically relevant nonmajor bleeding,were centrally evaluated by blinded investigators. Sinus recanalization on repeat brain imaging was a secondary outcome. Statistical analyses were exploratory. In total, 114 children with confirmed CVT were randomized. All children completed the follow-up. None of the 73 rivaroxaban recipients and 1 (2.4%; CVT) of the 41 standard anticoagulant recipients had symptomatic, recurrent VTE after 3 months (absolute difference, 2.4%; 95% confidence interval [CI], 22.6% to 13.5%). Clinically relevant bleeding occurred in 5 (6.8%; all nonmajor and noncerebral) rivaroxaban recipients and in 1 (2.5%; major [subdural] bleeding) standard anticoagulant recipient (absolute difference, 4.4%; 95% CI, 26.7% to 13.4%). Complete or partial sinus recanalization occurred in 18 (25%) and 39 (53%) rivaroxaban recipients and in 6 (15%) and 24 (59%) standard anticoagulant recipients, respectively. In summary, in this substudy of a randomized trial with a limited sample size, children with CVT treated with rivaroxaban or standard anticoagulation had a low risk of recurrent VTE and clinically relevant bleeding. This trial was registered at clinicaltrials.gov as #NCT02234843. © 2020 by The American Society of Hematology This study was supported by Bayer AG and Janssen Research and Development.

Background The long-term risk of major bleeding after discontinuing anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain. Objectives To determine the incidence of major bleeding up to 5 years after discontinuing anticoagulation for a first unprovoked VTE. Methods We searched MEDLINE, EMBASE, and Cochrane CENTRAL (from inception to January 2021) to identify relevant randomized controlled trials (RCTs) and prospective cohort studies reporting major bleeding after discontinuing anticoagulation in patients with a first unprovoked or weakly provoked VTE who had completed (IMAGE_)3 months of initial treatment. Unpublished data on major bleeding events and person-years were obtained from authors of included studies to calculate study-level incidence rates. Random-effects meta-analysis was used to pool results across studies. Results Of 1,123 records identified by the search, 20 studies (17 RCTs) and 8,740 patients were included in the analysis. During 13,011 person-years of follow-up after discontinuing anticoagulation, the pooled incidence of major bleeding (n = 41) and fatal bleeding (n = 7) per 100 person-years was 0.35 (95% confidence interval [CI]: 0.20–0.54) and 0.09 (95% CI: 0.05–0.15). The 5-year cumulative incidence of major bleeding was of 1.0% (95% CI: 0.4–2.4%). The case-fatality rate of major bleeding after discontinuing anticoagulation was 19.9% (95% CI: 10.6–31.1%). Conclusion The risk of major bleeding once anticoagulants are discontinued in patients with a first unprovoked VTE is not zero. Estimates from this study can help clinicians counsel patients about the incremental risk of major bleeding with extended anticoagulation to guide decision making about treatment duration for unprovoked VTE.

Background: The long-term risk for recurrent venous thromboembolism (VTE) during extended anticoagulation for a first unprovoked VTE is uncertain. Objectives: To determine the incidence of recurrent VTE during extended anticoagulation of up to 5years in patients with a first unprovoked VTE. Methods: MEDLINE, EMBASE, and the Cochrane CENTRAL were searched to identify randomized trials and prospective cohort studies reporting recurrent VTE among patients with a first unprovoked VTE who were to receive anticoagulation for a minimum of six additional months after completing ≥3months of initial treatment. Unpublished data on number of recurrent VTE and person-years, obtained from authors of included studies, were used to calculate study-level incidence rate, and random-effects meta-analysis was used to pool results. Results: Twenty-six studies and 15603 patients were included in the analysis. During 11631 person-years of follow-up, the incidence of recurrent VTE and fatal pulmonary embolism per 100 person-years was 1.41 (95% CI, 1.03–1.84) and 0.09 (0.04–0.16), with 5-year cumulative incidences of 7.1% (3.0%–13.2%) and 1.2% (0.4%–4.6%), respectively. The incidence of recurrent VTE was 1.08 (95% CI, 0.77–1.44) with direct oral anticoagulants and 1.55 (1.01–2.20) with vitamin K antagonists. The case-fatality rate of recurrent VTE was 4.9% (95% CI, 2.2%–8.7%). Conclusions: In patients with a first unprovoked VTE, the long-term risk of recurrent VTE during extended anticoagulation is low but not negligible. Thus, clinicians and patients should be aware of this risk and take appropriate and timely action in case of suspicion of recurrent VTE. Estimates from this study can be used to advise patients on what to expect while receiving extended anticoagulation, and estimate the net clinical benefit of extended treatment to guide long-term management of unprovoked VTE. © 2021 International Society on Thrombosis and Haemostasis.

Contains fulltext : 235339.pdf (Publisher’s version ) (Open Access) BACKGROUND: It is unknown whether differences in clot structure and resolution contribute to the reported risk differences of recurrent venous thromboembolism (VTE) between men and women. PATIENTS/METHODS: We used data from the EINSTEIN-PE study, a randomized, multicenter, non-inferiority study in which patients 18 years and older with acute symptomatic pulmonary embolism (PE) were randomized to rivaroxaban or enoxaparin followed by a vitamin K antagonist. PE was diagnosed by computed tomography pulmonary angiography scan or high-probability ventilation/perfusion scintigraphy. Three weeks after randomization a follow-up scan was performed. An independent adjudication committee assessed the degree of vascular obstruction. RESULTS AND CONCLUSIONS: A total of 371 participants including 174 (46.9%) women and 197 (53.0%) men were included in the present analysis. At 3 weeks, there was no difference between men and women in complete clot resolution: 39.6% and 40.2%, respectively. The absolute reduction in pulmonary vascular obstruction at week 3 was also similar: 12.9% (95% confidence interval [CI]: 11.6-14.2) in men and 12.1% (95% CI: 10.4-13.7) in women, corresponding to a resolution ratio of 0.29 (95% CI: 0.24-0.33) and 0.35 (95% CI: 0.28-0.42), respectively. No differences in clot resolution were observed between men and women diagnosed with acute PE at 3 weeks after start of anticoagulant therapy. These findings suggest that the reported higher rate of VTE recurrence in men cannot be explained by decreased clot resolution.

Background Rivaroxaban may induce heavy menstrual bleeding. It is unknown if this effect is dose related or if rivaroxaban is associated with more menstrual bleeding than aspirin. Objectives To demonstrate and compare menstrual patterns and actions taken among women receiving aspirin and two doses of rivaroxaban. Methods The EINSTEIN‐CHOICE trial compared once‐daily rivaroxaban 20 mg, rivaroxaban 10 mg, and aspirin 100 mg for extended treatment of venous thromboembolism in patients who had completed 6 to 12 months of anticoagulant therapy. In 362 women with menstrual cycles, menstrual flow duration and intensity assessed at days 30, 90, 180, and 360 were compared with those before starting anticoagulant therapy. Results Menstrual flow duration increased in 12%‐18% of the 134 women given 20‐mg rivaroxaban, in 6% to 12% of 120 women given 10‐mg rivaroxaban, and in 9% to 12% of 108 women given aspirin. Corresponding increases in flow intensity were 19% to 24%, 14% to 21%, and 13% to 20%. The odds ratios (ORs) for increased menstrual flow duration were 1.36 (95% confidence interval [CI], 0.62‐2.96) for rivaroxaban 20 mg versus aspirin, 0.77 (95% CI, 0.33‐1.81) for rivaroxaban 10 mg versus aspirin, and 0.57 (95% CI, 0.26‐1.25) for rivaroxaban 10 mg versus 20 mg. The ORs for increased menstrual flow intensity were 1.41 (95% CI, 0.67‐2.99), 1.07 (95% CI, 0.49‐2.34), and 0.76 (95% CI, 0.37‐ 1.57), respectively. Conclusions There were no statistically significant differences in menstrual hemorrhage patterns between women treated with 10 or 20 mg of rivaroxaban and aspirin. Compared with 10‐mg rivaroxaban or aspirin, 20‐mg rivaroxaban showed numerically more often increased menstrual flow duration and intensity.

BACKGROUND The long-term risk for major bleeding in patients receiving extended (beyond the initial 3 to 6 months) anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain. PURPOSE To determine the incidence of major bleeding during extended anticoagulation of up to 5 years among patients with a first unprovoked VTE, overall, and in clinically important subgroups. DATA SOURCES MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception to 23 July 2021. STUDY SELECTION Randomized controlled trials (RCTs) and prospective cohort studies reporting major bleeding among patients with a first unprovoked VTE who were to receive oral anticoagulation for a minimum of 6 additional months after completing at least 3 months of initial anticoagulant treatment. DATA EXTRACTION Two reviewers independently abstracted data and assessed study quality. Unpublished data required for analyses were obtained from authors of included studies. DATA SYNTHESIS Among the 14 RCTs and 13 cohort studies included in the analysis, 9982 patients received a vitamin K antagonist (VKA) and 7220 received a direct oral anticoagulant (DOAC). The incidence of major bleeding per 100 person-years was 1.74 events (95% CI, 1.34 to 2.20 events) with VKAs and 1.12 events (CI, 0.72 to 1.62 events) with DOACs. The 5-year cumulative incidence of major bleeding with VKAs was 6.3% (CI, 3.6% to 10.0%). Among patients receiving either a VKA or a DOAC, the incidence of major bleeding was statistically significantly higher among those who were older than 65 years or had creatinine clearance less than 50 mL/min, a history of bleeding, concomitant use of antiplatelet therapy, or a hemoglobin level less than 100 g/L. The case-fatality rate of major bleeding was 8.3% (CI, 5.1% to 12.2%) with VKAs and 9.7% (CI, 3.2% to 19.2%) with DOACs. LIMITATION Data were insufficient to estimate incidence of major bleeding beyond 1 year of extended anticoagulation with DOACs. CONCLUSION In patients with a first unprovoked VTE, the long-term risks and consequences of anticoagulant-related major bleeding are considerable. This information will help inform patient prognosis and guide decision making about treatment duration for unprovoked VTE. PRIMARY FUNDING SOURCE Canadian Institutes of Health Research. (PROSPERO: CRD42019128597).

Anticoagulant treatment of pediatric central venous catheter–related venous thromboembolism (CVC-VTE) has not been specifically evaluated. In EINSTEIN-Jr, 500 children with any VTE received rivaroxaban or standard anticoagulants. A predefined analysis of the CVC-VTE cohort was performed. Children with CVC-VTE (age, birth to 17 years) were administered rivaroxaban or standard anticoagulants during the 1-month (children

Background: Recently, the randomized EINSTEIN-Jr study showed similar efficacy and safety for rivaroxaban and standard anticoagulation for treatment of pediatric venous thromboembolism (VTE). The rivaroxaban dosing strategy was established based on phase 1 and 2 data in children and through pharmacokinetic (PK) modeling. Methods: Rivaroxaban treatment with tablets or the newly developed granules-for-oral suspension formulation was bodyweight-adjusted and administered once-daily, twice-daily, or thrice-daily for children with bodyweights of ≥30, ≥12 to (0-24)ss] and trough [C trough,ss] and maximum [C max,ss] steady-state plasma concentrations were derived using population PK modeling. Exposure-response graphs were generated to evaluate the potential relationship of individual PK parameters with recurrent VTE, repeat imaging outcomes, and bleeding or adverse events. A taste-and-texture questionnaire was collected for suspension-recipients. Results: Of the 335 children (aged 0-17 years) allocated to rivaroxaban, 316 (94.3%) were evaluable for PK analyses. Rivaroxaban exposures were within the adult exposure range. No clustering was observed for any of the PK parameters with efficacy, bleeding, or adverse event outcomes. Results were similar for the tablet and suspension formulation. Acceptability and palatability of the suspension were favorable. Discussion: Based on this analysis and the recently documented similar efficacy and safety of rivaroxaban compared with standard anticoagulation, we conclude that bodyweight-adjusted pediatric rivaroxaban regimens with either tablets or suspension are validated and provide for appropriate treatment of children with VTE.

Background: Recently, the randomised EINSTEIN-Jr. study showed similar efficacy and safety for rivaroxaban and standard anticoagulation for acute and continued treatment of paediatric venous thromboembolism (VTE). The rivaroxaban dosing strategy was established based on phase 1 and 2 data in children and through pharmacokinetic (PK) modeling. Methods: Rivaroxaban treatment with tablets or the newly-developed granules-for-oral suspension formulation was bodyweight-adjusted and administered once-daily, twice-daily or thrice-daily for children with bodyweights of ≥30, ≥12

Contains fulltext : 219893.pdf (Publisher’s version ) (Closed access) BACKGROUND: Treatment of venous thromboembolism in children is based on data obtained in adults with little direct documentation of its efficacy and safety in children. The aim of our study was to compare the efficacy and safety of rivaroxaban versus standard anticoagulants in children with venous thromboembolism. METHODS: In a multicentre, parallel-group, open-label, randomised study, children (aged 0-17 years) attending 107 paediatric hospitals in 28 countries with documented acute venous thromboembolism who had started heparinisation were assigned (2:1) to bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20-mg equivalent dose or standard anticoagulants (heparin or switched to vitamin K antagonist). Randomisation was stratified by age and venous thromboembolism site. The main treatment period was 3 months (1 month in children /=1 dose), were centrally assessed by investigators who were unaware of treatment assignment. Repeat imaging was obtained at the end of the main treatment period and compared with baseline imaging tests. This trial is registered with ClinicalTrials.gov, number NCT02234843 and has been completed. FINDINGS: From Nov 14, 2014, to Sept 28, 2018, 500 (96%) of the 520 children screened for eligibility were enrolled. After a median follow-up of 91 days (IQR 87-95) in children who had a study treatment period of 3 months (n=463) and 31 days (IQR 29-35) in children who had a study treatment period of 1 month (n=37), symptomatic recurrent venous thromboembolism occurred in four (1%) of 335 children receiving rivaroxaban and five (3%) of 165 receiving standard anticoagulants (hazard ratio [HR] 0.40, 95% CI 0.11-1.41). Repeat imaging showed an improved effect of rivaroxaban on thrombotic burden as compared with standard anticoagulants (p=0.012). Major or clinically relevant non-major bleeding in participants who received >/=1 dose occurred in ten (3%) of 329 children (all non-major) receiving rivaroxaban and in three (2%) of 162 children (two major and one non-major) receiving standard anticoagulants (HR 1.58, 95% CI 0.51-6.27). Absolute and relative efficacy and safety estimates of rivaroxaban versus standard anticoagulation estimates were similar to those in rivaroxaban studies in adults. There were no treatment-related deaths. INTERPRETATION: In children with acute venous thromboembolism, treatment with rivaroxaban resulted in a similarly low recurrence risk and reduced thrombotic burden without increased bleeding, as compared with standard anticoagulants. FUNDING: Bayer AG and Janssen Research & Development. 01 januari 2020

The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults. A physiologically based pharmacokinetic (PBPK) model for pediatric rivaroxaban dosing has been constructed. We quantitatively assessed the pharmacokinetics (PK) of a single rivaroxaban dose in children using population pharmacokinetic (PopPK) modelling and assessed the applicability of the PBPK model. Plasma concentration–time data from the EINSTEIN-Jr phase I study were analysed by non-compartmental and PopPK analyses and compared with the predictions of the PBPK model. Two rivaroxaban dose levels, equivalent to adult doses of rivaroxaban 10 mg and 20 mg, and two different formulations (tablet and oral suspension) were tested in children aged 0.5–18 years who had completed treatment for VTE. PK data from 59 children were obtained. The observed plasma concentration–time profiles in all subjects were mostly within the 90% prediction interval, irrespective of dose or formulation. The PopPK estimates and non-compartmental analysis-derived PK parameters (in children aged ≥6 years) were in good agreement with the PBPK model predictions. These results confirmed the applicability of the rivaroxaban pediatric PBPK model in the pediatric population aged 0.5–18 years, which in combination with the PopPK model, will be further used to guide dose selection for the treatment of VTE with rivaroxaban in EINSTEIN-Jr phase II and III studies. ClinicalTrials.gov number, NCT01145859 ; registration date: 17 June 2010.

Introduction For treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), rivaroxaban is given in fixed doses without routine coagulation monitoring. Patients and methods To determine whether monitoring would enhance its benefit-risk profile, we examined whether peak and trough prothrombin time (PT) values measured in 3797 rivaroxaban-treated patients included in the EINSTEIN DVT and PE studies correlated with subsequent recurrent VTE and major bleeding. In addition, we examined the stability of PT values over time and the impact of clinical variables on PT values. Results The mean peak PT values at months 3 and 6 or 12 were 21.9 ± 5 and 21.7 ± 6.0 s, respectively, while the mean trough PT values at months 2 and 6 were 15.1 ± 5.1 and 15.3 ± 2.9 s, respectively. Although peak and through PT values were higher in females, and with older age, frailty, active cancer, low body weight, impaired renal function and use of moderate to strong inhibitors of CYP3A4 and/or P-glycoprotein, and were lower in patients taking strong CYP 3A4 inducers, the differences were small and results were overlapping. Neither peak nor trough PT values correlated with recurrent VTE or major bleeding. Conclusions PT monitoring is unlikely to improve the benefit-risk profile of rivaroxaban in patients with DVT or PE. The study was registered at www.clinicaltrials.gov as # NCT00440193 (EINSTEIN-DVT) and # NCT00439777 (EINSTEIN-PE).

The optimal duration of anticoagulation for venous thromboembolism (VTE) is uncertain. In this prespecified analysis, we used data from 2 randomized trials, which compared once-daily rivaroxaban (20 mg or 10 mg) with aspirin (100 mg) or placebo for extended VTE treatment to estimate the risk of recurrence according to baseline risk factor profiles. Index VTE events were centrally classified as unprovoked, or provoked by major transient or persistent, or minor transient or persistent risk factors, and rates of recurrence at 1 year were calculated. A total of 2832 patients received rivaroxaban; 1131 received aspirin, and 590 received placebo. With unprovoked VTE, rates of recurrence in the 1173 patients given rivaroxaban, the 468 given aspirin, and the 243 given placebo were 2.0%, 5.9%, and 10.0%, respectively. There were no recurrences in patients with VTE provoked by major transient risk factors. With VTE provoked by minor persistent risk factors, recurrence rates in the 1184 patients given rivaroxaban, the 466 given aspirin, and the 248 given placebo were 2.4%, 4.5%, and 10.7%, respectively. For patients with minor transient risk factors, recurrence rates were 0.4% in the 268 patients given rivaroxaban, 4.2% in the 121 given aspirin, and 7.1% in the 56 given placebo. Recurrence rates in patients with VTE provoked by minor persistent or minor transient risk factors were not significantly lower than that with unprovoked VTE (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.56-1.16; and HR, 0.68; 95% CI, 0.32-1.30, respectively). Therefore, such patients may also benefit from extended anticoagulation therapy.

Background: The results of the EINSTEIN-DVT/PE and AMPLIFY trials, which compared rivaroxaban and apixaban with conventional anticoagulation therapy for acute venous thromboembolism (VTE), respectively, are often compared. However, the trials differed in duration of therapy (3-12 and 6 months, respectively) and in patient selection (few exclusion criteria and more stringent exclusion criteria, respectively).Methods: To determine the effect of these methodological differences on outcomes, the patients enrolled in EINSTEIN-DVT/PE were divided into 2 cohorts; the 5253 patients that matched the exclusion criteria for AMPLIFY and were treated for at least 6 months (cohort 1) and the 2368 patients who would have been ineligible for AMPLIFY (cohort 2).Results: Compared with patients in cohort 2, those in cohort 1 were older and more often male and there were more with unprovoked VTE, prior VTE, cancer and known thrombophilia. In cohort 1, rivaroxaban would have significantly reduced recurrent VTE (relative risk [RR], 0.64; 95% confidence interval [CI], 0.43-0.95) and major bleeding (RR, 0.50; 95% CI, 0.30-0.82) compared with conventional therapy, whereas the two treatments would have had similar effects on recurrent VTE (RR, 1.08; 95% CI, 0.65-1.79) and major bleeding (RR, 1.03; 95% CI, 0.48-2.18) in cohort 2.Conclusions: This analysis illustrates the influence of patient selection and treatments duration on outcome results and highlights the limitations of cross-trial comparisons. (C) 2016 Elsevier Ltd. All rights reserved.

Background Rivaroxaban has been shown to be efficacious for treatment of venous thromboembolism in adults, and has a reduced risk of bleeding compared with standard anticoagulants. We aimed to develop paediatric rivaroxaban regimens for the treatment of venous thromboembolism in children and adolescents. Methods In this phase 2 programme, we did three studies to evaluate rivaroxaban treatment in children younger than 6 months, aged 6 months to 5 years, and aged 6-17 years. Our studies used a multicentre, single-arm design at 54 sites in Australia, Europe, Israel, Japan, and north America. We included children with objectively confirmed venous thromboembolism previously treated with low-molecular weight heparin, fondaparinux, or a vitamin K antagonist for at least 2 months or, in children who had catheter-related venous thromboembolism for at least 6 weeks. We administered rivaroxaban orally in a bodyweight-adjusted 20 mg-equivalent dose, based on physiologically-based pharmacokinetic modelling predictions and EINSTEIN-Jr phase 1 data in young adults, in either a once-daily (tablets; for those aged 6-17 years), twice-daily (in suspension; for those aged 6 months to 11 years), or three times-daily (in suspension; for those younger than 6 months) dosing regimen for 30 days (or 7 days for those younger than 6 months). The primary aim was to define rivaroxaban treatment regimens that match the target adult exposure range. The principal safety outcome was major bleeding and clinically relevant non-major bleeding. Analyses were per-protocol. The predefined efficacy outcomes were symptomatic recurrent venous thromboembolism, asymptomatic deterioration on repeat imaging at the end of the study treatment period. These trials are registered at ClinicalTrials.gov, numbers NCT02564718, NCT02309411, and NCT02234843. Findings Between Feb 11, 2013, and Dec 20, 2017, we enrolled 93 children (ten children younger than 6 months; 15 children aged 6 months to 1 year; 25 children aged 2-5 years; 32 children aged 6-11 years; and 11 children aged 12-17 years) into our study. 89 (96%) children completed study treatment (30 days of treatment, or 7 days in those younger than 6 months), and 93 (100%) children received at least one dose of study treatment and were evaluable for the primary endpoints. None of the children had a major bleed, and four (4%, 95% CI 1.2-10.6) of these children had a clinically relevant non-major bleed (three children aged 12-17 years with menorrhagia and one child aged 6-11 years with gingival bleeding). We found no symptomatic recurrent venous thromboembolism in any patients (0%, 0.0-3.9). 24 (32%) of 75 patients with repeat imaging had their thrombotic burden resolved, 43 (57%) patients improved, and eight (11%) patients were unchanged. No patient deteriorated. We confirmed therapeutic rivaroxaban exposures with once-daily dosing in children with bodyweights of at least 30 kg and with twice-daily dosing in children with bodyweights of at least 20 kg and less than 30 kg. Children with low bodyweights (

On the basis of the low observed prevalence of pulmonary embolism (PE) in a cohort of patients with syncope (BASEL IX [Basel Syncope Evaluation]; [NCT01548352][1]), Badertscher et al. ([1][2]) conclude that a systematic search for PE is not indicated. This conclusion seems in contrast to the

Objectives To determine the rate of a first recurrent venous thromboembolism (VTE) event after discontinuation of anticoagulant treatment in patients with a first episode of unprovoked VTE, and the cumulative incidence for recurrent VTE up to 10 years. Design Systematic review and meta-analysis. Data sources Medline, Embase, and the Cochrane Central Register of Controlled Trials (from inception to 15 March 2019). Study selection Randomised controlled trials and prospective cohort studies reporting symptomatic recurrent VTE after discontinuation of anticoagulant treatment in patients with a first unprovoked VTE event who had completed at least three months of treatment. Data extraction and synthesis Two investigators independently screened studies, extracted data, and appraised risk of bias. Data clarifications were sought from authors of eligible studies. Recurrent VTE events and person years of follow-up after discontinuation of anticoagulant treatment were used to calculate rates for individual studies, and data were pooled using random effects meta-analysis. Sex and site of initial VTE were investigated as potential sources of between study heterogeneity. Results 18 studies involving 7515 patients were included in the analysis. The pooled rate of recurrent VTE per 100 person years after discontinuation of anticoagulant treatment was 10.3 events (95% confidence interval 8.6 to 12.1) in the first year, 6.3 (5.1 to 7.7) in the second year, 3.8 events/year (95% confidence interval 3.2 to 4.5) in years 3-5, and 3.1 events/year (1.7 to 4.9) in years 6-10. The cumulative incidence for recurrent VTE was 16% (95% confidence interval 13% to 19%) at 2 years, 25% (21% to 29%) at 5 years, and 36% (28% to 45%) at 10 years. The pooled rate of recurrent VTE per 100 person years in the first year was 11.9 events (9.6 to 14.4) for men and 8.9 events (6.8 to 11.3) for women, with a cumulative incidence for recurrent VTE of 41% (28% to 56%) and 29% (20% to 38%), respectively, at 10 years. Compared to patients with isolated pulmonary embolism, the rate of recurrent VTE was higher in patients with proximal deep vein thrombosis (rate ratio 1.4, 95% confidence interval 1.1 to 1.7) and in patients with pulmonary embolism plus deep vein thrombosis (1.5, 1.1 to 1.9). In patients with distal deep vein thrombosis, the pooled rate of recurrent VTE per 100 person years was 1.9 events (95% confidence interval 0.5 to 4.3) in the first year after anticoagulation had stopped. The case fatality rate for recurrent VTE was 4% (95% confidence interval 2% to 6%). Conclusions In patients with a first episode of unprovoked VTE who completed at least three months of anticoagulant treatment, the risk of recurrent VTE was 10% in the first year after treatment, 16% at two years, 25% at five years, and 36% at 10 years, with 4% of recurrent VTE events resulting in death. These estimates should inform clinical practice guidelines, enhance confidence in counselling patients of their prognosis, and help guide decision making about long term management of unprovoked VTE. Systematic review registration PROSPERO CRD42017056309.

Background: Treatment of venous thromboembolism (VTE) in children is based on data obtained in adults with little direct documentation of its efficacy and safety in children. Methods: In a parallel-group open-label randomised study, 500 children aged birth to 17 years with documented acute VTE who had started heparinisation were assigned, in a 2:1 ratio, to receive bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20-mg equivalent dose or standard anticoagulants. The main treatment period was 3 months (1 month in children under 2 years with catheter-related VTE). Symptomatic recurrent VTE and bleeding were centrally assessed unaware of treatment assignment. Repeat imaging was obtained at the end of the treatment period. Findings: Recurrent VTE was the primary efficacy outcome and occurred in 4 of the 335 (1.2%) children allocated to rivaroxaban and in 5 of the 165 (3.0%) children allocated to standard anticoagulants (64.2% of whom received subcutaneous heparins only), for a hazard ratio of 0.40 (95% confidence interval, 0.11 to 1.41). Repeat imaging showed an improved effect of rivaroxaban on thrombotic burden as compared with standard anticoagulants (P=0.012). Major or clinically relevant non-major bleeding was the principal safety outcome and occurred in 10 children (3.0%; all non-major) with rivaroxaban and in 3 children (1.9%; two major and 1 non-major) with standard anticoagulants. Absolute and relative efficacy and safety estimates of rivaroxaban versus standard anticoagulation estimates were comparable those obtained in rivaroxaban studies in adults. Interpretation: In children with acute VTE, treatment with rivaroxaban resulted in a low recurrence risk and a reduced thrombotic burden without increased bleeding, as compared to standard anticoagulants. Trial Registration: This trial is registered with ClinicalTrials.gov, number NCT02234843. Funding Statement: Bayer AG and Janssen Research & Development, LLC. Declaration of Interests: CM reports receiving personal fees and fees, paid to his institution, from Bayer, Bristol-Myers-Squibb, Pfizer and fees, paid to his institution, from BoehringerIngelheim; AWAL being employed by Bayer; RK receiving personal fees from Bayer, CSL Behring, and Kedrion; DB receiving personal fees and grant support from Actelion Pharmaceuticals, Bayer, Eli Lilly, BMS, and Novartis and grant support from AbbVie; PC receiving personal fees from Onyx Health Limited; AKC receiving personal fees from Bayer and fees, paid to his institution, from Bayer, Pfizer, Daiichi Sankyo, and Bristol-Myers-Squibb; GK receiving personal fees from Bayer, Boehringer Ingelheim, and Daiichi-Sankyo and fees, paid to her institution from Pfizer; SH receiving personal fees from P and fees, paid to her institution, from Bayer, Pfizer, and Daiichi Sankyo; AS receiving personal fees from Bayer, Pfizer, Daiichi Sankyo and Boehringer Ingelheim; PA receiving personal fees and fees, paid to his institution, from Abbvie and Bayer, and fees paid to his institution from Actelion, Novartis, and Daiichi Sankyo; EC receiving personal fees from Boehringer Ingelheim and Bristol-Myers-Squibb, and fees, paid to her institution from Bayer, Pfizer, and Daiichi Sankyo; DLY receiving fees, paid to his institution, from Bayer, Pfizer, and Bristol-Myers Squibb; OL receiving personal fees from Bayer, Pfizer, Boehringer Ingelheim, and Novartis, and fees, paid to her institution, from Bayer; JB-W receiving personal fees and fees, paid to his institution, from Bayer, Daiichi Sankyo, DOASENSE and Portola and fees, paid to his institution, from Pfizer; TTB receiving fees from Boehringer Ingelheim and Bayer, and grant support from Leo Pharma; IM receiving fees from Sanofi and Bayer; MP receiving grant support from Pfizer and Sobi; MPM receiving personal fees from Bayer; GY receiving receiving personal fees from GlaxoSmithKline and Portola and personal fees and fees paid to his institution from Bayer and Daiichi Sankyo; AFP, MM, WTS, SDB, KT, DK being employed by Bayer; JH was employed by Bayer; MC receiving grant support from and serving on a data and safety monitoring board for Bayer, receiving advisory board fees from Shionogi, Octapharma, Bristol-Myers Squibb Canada, and Asahi Kasei, receiving educational funding from Alexion Pharmaceuticals, Pfizer, CSL Behring, and Diagnostica Stago, receiving grant support, paid to his institution, from Leo Pharma, serving on a data and safety monitoring board for Daiichi Sankyo, owning stock in Alnylam Pharmaceuticals, and receiving educational funding and advisory board fees from Servier Canada; MHP receiving personal fees from Bayer; no other potential conflict of interest relevant to this article was reported. Ethics Approval Statement: The protocol was approved by the institutional review board at each participating center. Written permission from a parent or guardian and, when appropriate, child assent, were obtained.

Background Short-term anticoagulant treatment for acute DVT or pulmonary embolism (PE) effectively reduces the risk of recurrent disease during the first 6 to 12 months of therapy. Continued anticoagulation often is not instituted because of the perception among physicians that the risk of major bleeding will outweigh the risk of new venous thrombotic episodes. Methods The authors performed a benefit-risk analysis by using the randomized EINSTEIN-Extension trial, which compared continued rivaroxaban with placebo in 1,197 patients with symptomatic DVT or PE who had completed 6 to 12 months of anticoagulation and in whom physicians had equipoise with respect to the need for continued anticoagulation. One-year Kaplan-Meier rates and rate differences of recurrent VTE and major bleeding were calculated. Benefits and risks were assessed using rate differences scaled to a population size of 10,000 patients treated for 1 year. Results Recurrent VTE occurred in eight recipients of rivaroxaban and 42 patients receiving placebo. In a population of 10,000 patients treated for 1 year, rivaroxaban treatment would have resulted in 665 (95% CI, 246-1,084) fewer recurrent VTEs than would placebo (number needed to treat = 15). Major bleeding occurred in four (0.7%) and zero patients, respectively. Rivaroxaban treatment would have resulted in 68 (95% CI, 2-134) more major bleeding events than would placebo (number needed to harm = 147). Kaplan-Meier analysis showed early recurrent VTE reduction with rivaroxaban that continued to improve throughout treatment; major bleeding increased gradually, plateauing at approximately 100 days. Conclusions A clinically important benefit and a favorable benefit-risk profile of continued rivaroxaban anticoagulation was observed. Trial Registry ClinicalTrials.gov; No.: NCT00439725 ; URL: www.clinicaltrials.gov

BACKGROUND The prevalence of pulmonary embolism among patients hospitalized for syncope is not well documented, and current guidelines pay little attention to a diagnostic workup for pulmonary embolism in these patients. METHODS We performed a systematic workup for pulmonary embolism in patients admitted to 11 hospitals in Italy for a first episode of syncope, regardless of whether there were alternative explanations for the syncope. The diagnosis of pulmonary embolism was ruled out in patients who had a low pretest clinical probability, which was defined according to the Wells score, in combination with a negative D-dimer assay. In all other patients, computed tomographic pulmonary angiography or ventilation-perfusion lung scanning was performed. RESULTS A total of 560 patients (mean age, 76 years) were included in the study. A diagnosis of pulmonary embolism was ruled out in 330 of the 560 patients (58.9%) on the basis of the combination of a low pretest clinical probability of pulmonary embolism and negative D- dimer assay. Among the remaining 230 patients, pulmonary embolism was identified in 97 (42.2%). In the entire cohort, the prevalence of pulmonary embolism was 17.3% (95% confidence interval, 14.2 to 20.5). Evidence of an embolus in a main pulmonary or lobar artery or evidence of perfusion defects larger than 25% of the total area of both lungs was found in 61 patients. Pulmonary embolism was identified in 45 of the 355 patients (12.7%) who had an alternative explanation for syncope and in 52 of the 205 patients (25.4%) who did not. CONCLUSIONS Pulmonary embolism was identified in nearly one of every six patients hospitalized for a first episode of syncope.

Women receiving vitamin K antagonists (VKAs) require adequate contraception because of the potential for fetal complications. It is unknown if the use of hormonal therapy, especially those containing estrogens, is associated with recurrent venous thromboembolism (VTE) during anticoagulation. Despite the absence of data, World Health Organization guidelines state that use of estrogen-containing contraceptives confers an "unacceptable health risk" during established anticoagulation for VTE. We compared the incidences of recurrent VTE and abnormal uterine bleeding with and without concomitant hormonal therapy in women aged

SummaryPost-thrombotic syndrome (PTS) is a common complication of deepvein thrombosis (DVT). Poor quality treatment with vitamin K antagonists (VKA) is a risk factor for PTS. We hypothesised that treatment with the direct oral anticoagulant (DOAC) rivaroxaban may lower PTS incidence as compared to enoxaparin/VKA, as DOACs have a more stable pharmacologic profile than VKA. We performed a post-hoc subgroup analysis of the Einstein DVT trial (n=3449). Kaplan-Meier survival analysis was performed to compare the cumulative incidence of PTS between the rivaroxaban and enoxaparin/VKA groups. Hazard ratios (HR) and 95 % confidence intervals (CI) were calculated using Cox proportional hazards models. We included 336 patients with a mean age of 58 ± 16 years and a median follow-up after index DVT of 57 months (interquartile range 48–64). Of these, 162 (48 %) had been treated with rivaroxaban and 174 (52 %) with enoxaparin/VKA. The cumulative PTS incidence at 60 months follow-up was 29 % in the rivaroxaban group and 40 % in the enoxaparin/VKA group. After adjusting for age, gender, body mass index, previous VTE, ipsilateral recurrent DVT, extent of DVT, idiopathic DVT, duration of anticoagulant treatment, compliance to assigned study medication, elastic compression stocking use and active malignancy, the HR of PTS development for rivaroxaban was 0.76 (95 % CI: 0.51–1.13). In conclusion, treatment of acute DVT with rivaroxaban was associated with a numerically lower but statistically non-significant risk of PTS compared to enoxaparin/VKA treatment. The potential effect on reducing PTS deserves evaluation in a large randomised trial.Supplementary Material to this article is available online at www.thrombosis-online.com.

Objectives Outpatient treatment of acute venous thromboembolism (VTE) requires the selection of patients with a low risk of bleeding during the first few weeks of anticoagulation. The accuracy of four systems, originally derived for predicting bleeding in VTE treated with vitamin K antagonists (VKAs), was assessed in VTE patients treated with rivaroxaban. Methods All patients treated with rivaroxaban in the multinational EINSTEIN deep vein thrombosis (DVT) and pulmonary embolism (PE) trials were included. Major bleeding was defined as ≥2 g/dL drop in hemoglobin or ≥2-unit blood transfusion, bleeding in critical area, or bleeding contributing to death. The authors examined the incidence of major bleeding in patients with low-risk assignment by the systems of Ruiz-Gimenez et al. (score = 0 to 1), Beyth et al. (score = 0), Kuijer et al. (score = 0), and Landefeld and Goldman. (score = 0). For clinical relevance, the definition of low risk for all scores except Kuijer includes all patients

BACKGROUND: Using data from the Reduced-Dose Rivaroxaban in the Long-Term Prevention of Recurrent Symptomatic Venous Thromboembolism (EINSTEIN-CHOICE) trial, this study assessed cost impact of continued anticoagulation therapy with rivaroxaban vs aspirin.METHODS: Total health-care costs (2016 USD) associated with rivaroxaban and aspirin were calculated as the sum of clinical event costs and drug costs from a US managed care perspective. Clinical event costs were calculated by multiplying event rate by cost of care. One-year Kaplan-Meier clinical event rates for recurrent pulmonary embolism, recurrent DVT, all-cause mortality, and bleeding were obtained from EINSTEIN-CHOICE. Cost of care was determined by literature review. Drug costs were the product of drug price (wholesale acquisition cost) and treatment duration. A one-way sensitivity analysis was conducted.RESULTS: Rivaroxaban users had lower per patient per month (PPPM) clinical event costs compared with aspirin users ($123, $243, and $381 for rivaroxaban 10 mg, rivaroxaban 20 mg, and aspirin, respectively). However, vs aspirin, PPPM total health-care costs were $24 higher for patients treated with rivaroxaban 10 mg ($143 higher for rivaroxaban 20 mg) due to higher cost of rivaroxaban. With a 15% discount for rivaroxaban 10 mg, the lower cost of clinical events for the rivaroxaban-treated patients more than fully offset the higher drug costs, and yielded a $19 lower total health-care cost.CONCLUSIONS: Continued therapy with rivaroxaban 10 and 20 mg vs aspirin was associated with lower clinical event costs but higher total health-care costs; with a 15% drug discount rivaroxaban 10 mg had lower total health-care costs than aspirin.

Background The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults. Methods This was a multinational, single-dose, open-label, phase I study to describe the pharmacodynamics (PD), pharmacokinetics (PK) and safety of a single bodyweight-adjusted rivaroxaban dose in children aged 0.5–18 years. Children who had completed treatment for a venous thromboembolic event were enrolled into four age groups (0.5–2 years, 2–6 years, 6–12 years and 12–18 years) receiving rivaroxaban doses equivalent to 10 mg or 20 mg (either as a tablet or oral suspension). Blood samples for PK and PD analyses were collected within specified time windows. Results Fifty-nine children were evaluated. In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time and anti-Factor Xa activity) showed a linear relationship versus rivaroxaban plasma concentrations and were in line with previously acquired adult data, as well as in vitro spiking experiments. The rivaroxaban pediatric physiologically based pharmacokinetic model, used to predict the doses for the individual body weight groups, was confirmed. No episodes of bleeding were reported, and treatment-emergent adverse events occurred in four children and all resolved during the study. Conclusions Bodyweight-adjusted, single-dose rivaroxaban had predictable PK/PD profiles in children across all age groups from 0.5 to 18 years. The PD assessments based on prothrombin time and activated partial thromboplastin time demonstrated that the anticoagulant effect of rivaroxaban was not affected by developmental hemostasis in children. Trial registration ClinicalTrials.gov number, NCT01145859.

Background Venous thromboembolism (VTE) is a relatively rare condition in childhood with treatment mainly based on extrapolation from studies in adults. Therefore, clinical trials of anticoagulation in children require novel approaches to deal with numerous challenges. The EINSTEIN-Jr program identified pediatric rivaroxaban regimens commencing with in vitro dose finding studies followed by evaluation of children of different ages through phase I and II studies using extensive modeling to determine bodyweight-related doses. Use of this approach resulted in drug exposure similar to that observed in young adults treated with rivaroxaban 20 mg once-daily. Methods EINSTEIN-Jr phase III is a randomized, open-label, study comparing the efficacy and safety of rivaroxaban 20 mg-equivalent dose regimens with those of standard anticoagulation for the treatment of any types of acute VTE in children aged 0–18 years. A total of approximately 500 children are expected to be included during the 4-year study window. Flexibility of treatment duration is allowed with study treatment to be given for 3 months with the option to continue treatment in 3-month increments, up to a total of 12 months. However, based on most common current practice, children younger than 2 years with catheter-related thrombosis will have a main treatment period of 1 month with the option to prolong treatment in 1-month increments, up to a total of 3 months. Conclusions EINSTEIN-Jr will compare previously established 20 mg-equivalent rivaroxaban dosing regimens with standard anticoagulation for the treatment of VTE in children. Demonstration of similarity of disease, as well as equivalent rivaroxaban exposure and exposure-response will enable extrapolation of efficacy from adult trials, which is critical given the challenges of enrollment in pediatric anticoagulation trials. Trial registration Clinicaltrials.gov NCT02234843, registered on 9 September 2014.

Background Full- or lower-dose anticoagulant therapy or aspirin can be used for extended therapy in patients with venous thromboembolism (VTE), but information on their relative benefit-risk profiles is limited. Methods Data from the EINSTEIN-CHOICE trial were used to compare the benefit-risk profiles of extended treatment with rivaroxaban (20 or 10 mg once daily) and aspirin (100 mg once daily) in VTE patients who had completed 6 to 12 months of anticoagulation therapy. One-year cumulative incidences of recurrent VTE and major bleeding were estimated and benefits and risks were calculated by determining the between group differences in a hypothetical population of 10,000 VTE patients treated for 1 year. Findings A total of 1107 patients were treated with 20 mg of rivaroxaban, 1127 with 10 mg of rivaroxaban, and 1131 with aspirin. The cumulative incidences of recurrent VTE in the rivaroxaban 20-mg, rivaroxaban 10-mg and aspirin groups were 1.9%, 1.6%, and 5.0%, respectively, whereas the cumulative incidences of major bleeding were 0.7%, 0.4% and 0.5%, respectively. The incidences of the combined outcome of recurrent VTE and major bleeding were 2.8% and 3.4% lower in the rivaroxaban 20-mg and 10-mg groups than in the aspirin group. For 10,000 patients treated for 1 year, there would be 284 (95% confidence interval [CI] 106 to 462) and 339 (95% CI 165 to 512) fewer events with rivaroxaban 20 mg or 10 mg than with aspirin. Interpretation Compared with aspirin, extended anticoagulation with once daily rivaroxaban reduces recurrent VTE with a favourable benefit-risk profile. Funding Bayer AG.

Background: Venous thromboembolism (VTE) in young children is not well documented. Methods: Clinicians from 12 institutions retrospectively evaluated the presentation, therapeutic management, and outcome of VTE in children younger than 2 years seen in 2011-2016. Feasibility of recruiting these children in EINSTEIN-Jr. phase III, a randomized trial evaluating rivaroxaban versus standard anticoagulation for VTE, was assessed. Results: We identified 346 children with VTE, of whom 227 (65.6%) had central venous catheter-related thrombosis (CVC-VTE), 119 (34.4%) had non-CVC-VTE, and 156 (45.1%) were younger than 1 month. Of the 309 children who received anticoagulant therapy, 86 (27.8%) had a short duration of therapy (i.e. < 6 weeks for CVC-VTE and < 3 months for non-CVC-VTE) and 17 (5.5%) had recurrent VTE during anticoagulation (n = 8, 2.6%) or shortly after its discontinuation (n = 9, 2.9%). A total of 37 (10.7%) children did not receive anticoagulant therapy and 4 (10.5%) had recurrent VTE. The average number of children aged < 0.5 years and 0.5-2 years who would have been considered for enrolment in EINSTEIN-Jr is approximately 1.0 and 0.9 per year per site, respectively. Conclusions: Young children with VTE most commonly have CVC-VTE and approximately one-tenth and one-fourth received no or only short durations of anticoagulant therapy, respectively. Recurrent VTE rates without anticoagulation, during anticoagulation or shortly after its discontinuation seem comparable to those observed in adults. Short and flexible treatment durations could potentially increase recruitment in EINSTEIN-Jr. phase III.

The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6-12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (-$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI] = -$1,454 [-$2,396, $1,231]).This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited "real-world" applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6-12 months of VTE treatment.

SummaryVitamin K antagonists (VKA) are used to prevent recurrent disease in patients with venous thromboembolism (VTE). Their efficacy and safety depend on individual time in therapeutic range (iTTR) and variability of International Normalised Ratios (INR). We aimed to identify independent predictors of poor VKA control > 28 days. In a prospective cohort of 3825 VTE patients, separate logistic regression analyses were performed to identify predictors of low iTTR (first quartile) and instability (iTTR median). Subsequently, the association between these predictors and clinical outcomes was investigated. Weight < 50 kg (odds ratio [OR]=1.89; 95 % confidence interval [CI] 1.03–3.49), active cancer at baseline (OR=1.52; CI1.05–2.19), secondary VTE (OR=1.42; CI1.20–1.68), and INR < 2.0 at stop of double therapy (OR=1.35; CI1.09–1.67) were independent predictors of low iTTR. The first two were also predictive for instability (OR=1.96; CI1.06–3.63 and OR=1.95; CI1.36–2.80, respectively). ORs of early ( 28 days) low iTTR and instability depended on VKA type. In acenocoumarol users, early low iTTR was an independent predictor of subsequent low iTTR (OR=1.92; CI1.31–2.80) and instability (OR=1.55; CI1.07–2.23). In warfarin users, early low iTTR (OR=1.36; CI1.09–1.69) and instability (OR=1.25; CI1.01–1.55) were additionally predictive for low iTTR, but only the latter was predictive for instability (OR=1.91; CI1.57–2.32). Many predictors of VKA control also predicted premature discontinuation, but only region was prognostic for clinical outcome. In conclusion, we identified several independent predictors of low iTTR and instability > 28 days, which showed some similarities but did not fully overlap. Early VKA control was of additional value for prediction of both, but had to be interpreted in the context of VKA type.

SummaryPatients with unprovoked venous thromboembolism (VTE) are at high risk for recurrence. Although rivaroxaban is effective for extended VTE treatment at a dose of 20 mg once daily, use of the 10 mg dose may further improve its benefit-to-risk ratio. Low-dose aspirin also reduces rates of recurrent VTE, but has not been compared with anticoagulant therapy. The EINSTEIN CHOICE study is a multicentre, randomised, double-blind, active-controlled, event-driven study comparing the efficacy and safety of two once daily doses of rivaroxaban (20 and 10 mg) with aspirin (100 mg daily) for the prevention of recurrent VTE in patients who completed 6–12 months of anticoagulant therapy for their index acute VTE event. All treatments will be given for 12 months. The primary efficacy objective is to determine whether both doses of rivaroxaban are superior to aspirin for the prevention of symptomatic recurrent VTE, while the principal safety outcome is the incidence of major bleeding. The trial is anticipated to enrol 2,850 patients from 230 sites in 31 countries over a period of 27 months. In conclusion, the EINSTEIN CHOICE study will provide new insights into the optimal antithrombotic strategy for extended VTE treatment by comparing two doses of rivaroxaban with aspirin (clinicaltrials.gov NCT02064439).

Background: The EINSTEIN-extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (versus placebo) after the initial 6-12 months of anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small increased risk of major bleeding (none was fatal or in a critical site). This study aimed to assess the cost impact of rivaroxaban vs. placebo based on EINSTEIN-EXT recurrent VTE and bleed rates. Methods: Total costs were calculated as the sum of drug and clinical event costs, and compared between cohorts from a US managed care perspective. Treatment duration and event rates were obtained from EINSTEIN-EXT. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e., recurrent VTE, major bleeding, clinically relevant nonmajor bleeding, and mortality) were determined based on a targeted literature review. Results were examined over a ± 20% range of each cost component in a one-way sensitivity analysis approach. Results: Total cost per person was $1,161 lower for rivaroxaban (vs. placebo) in the base case, with lower cost of clinical events fully offsetting drug costs (Figure 1). The difference in recurrent DVT alone (-$3,102) was greater than drug cost ($3,025). Total cost of rivaroxaban remained lower than placebo in sensitivity analyses. Conclusions: Rivaroxaban is associated with lower total costs compared to placebo in VTE patients who had completed 6 to 12 months of VTE treatment.

Summary Background Patients with venous thromboembolism and cancer have a substantial risk of recurrent venous thromboembolism and bleeding during anticoagulant therapy. Although monotherapy with low-molecular-weight heparin is recommended in these patients, in clinical practice many patients with venous thromboembolism and cancer do not receive this treatment. We aimed to assess the efficacy and safety of a single-drug regimen with oral rivaroxaban compared with enoxaparin followed by vitamin K antagonists, in the subgroup of patients with cancer enrolled in the EINSTEIN-DVT and EINSTEIN-PE randomised controlled trials. Methods We did a subgroup analysis of patients with active cancer (either at baseline or diagnosed during the study), a history of cancer, or no cancer who were enrolled in the EINSTEIN-DVT and EINSTEIN-PE trials. Eligible patients with deep-vein thrombosis (EINSTEIN-DVT) or pulmonary embolism (EINSTEIN-PE) were randomly assigned in a 1:1 ratio to receive rivaroxaban (15 mg twice daily for 21 days, followed by 20 mg once daily) or standard therapy (enoxaparin 1·0 mg/kg twice daily and warfarin or acenocoumarol; international normalised ratio 2·0–3·0). Randomisation with a computerised voice-response system was stratified according to country and intended treatment duration (3, 6, or 12 months). The prespecified primary efficacy and safety outcomes of both the trials and this subanalysis were symptomatic recurrent venous thromboembolism and clinically relevant bleeding, respectively. We did efficacy and mortality analyses in the intention-to-treat population, and bleeding analyses for time spent receiving treatment plus 2 days in the safety population (all patients who received at least one dose of study drug). The EINSTEIN-DVT and EINSTEIN-PE studies are registered at ClinicalTrials.gov, numbers NCT00440193 and NCT00439777. Findings In patients with active cancer (diagnosed at baseline or during treatment), recurrent venous thromboembolism occurred in 16 (5%) of 354 patients allocated to rivaroxaban and 20 (7%) of 301 patients allocated to enoxaparin and vitamin K antagonist (hazard ratio [HR] 0·67, 95% CI 0·35 to 1·30). Clinically relevant bleeding occurred in 48 (14%) of 353 patients receiving rivaroxaban and in 49 (16%) of 298 patients receiving standard therapy (HR 0·80, 95% CI 0·54 to 1·20). Major bleeding occurred in eight (2%) of 353 patients receiving rivaroxaban and in 15 (5%) of 298 patients receiving standard therapy (HR 0·42, 95% CI 0·18 to 0·99). The overall frequency of recurrent venous thromboembolism in patients with only a history of cancer (five [2%] of 233 patients in the rivaroxaban group vs five [2%] of 236 in the standard therapy group; HR 0·98, 95% CI 0·28–3·43) was similar to that of patients without cancer (65 [2%] of 3563 vs 70 [2%] of 3594, respectively; HR 0·93, 95% CI 0·66–1·30), but the frequency was increased in patients with active cancer at baseline (six [2%] of 258 vs eight [4%] of 204, respectively; HR 0·62, 95% CI 0·21–1·79) and most markedly increased in patients whose diagnosis of cancer was made during the study (ten [10%] of 96 vs 12 [12%] of 97, respectively; HR 0·80, 95% CI 0·34–1·88). The overall frequency of major bleeding in patients with only a history of cancer (one [ vs four [2%] patients in the standard therapy group; HR 0·23, 95% CI 0·03–2·06) was similar to that of patients without cancer (31 [1%] vs 53 [1%], respectively; HR 0·58, 95% CI 0·37–0·91), but was increased in patients with active cancer at baseline (five [2%] vs eight [4%], respectively; HR 0·47, 95% CI 0·15–1·45) and was highest in those with cancer diagnosed during the study (three [3%] vs seven [7%], respectively; HR 0·33, 95% CI 0·08–1·31). Interpretation In patients with active cancer and venous thromboembolism, rivaroxaban had similar efficacy to prevent recurrence of venous thromboembolism and reduced the number major bleeding events compared with treatment with enoxaparin and a vitamin K antagonist, although there was no difference between groups for clinically relevant bleeding. Based on these results, a head-to-head comparison of rivaroxaban with long-term low-molecular-weight heparin in patients with cancer is warranted. Funding Bayer HealthCare Pharmaceuticals and Janssen Research & Development.

IMPORTANCE Combined anticoagulant and aspirin therapy is associated with increased bleeding risk in patients with atrial fibrillation, but the bleeding risk of combined use of anticoagulant and nonsteroidal anti-inflammatory drugs (NSAIDs) is poorly documented.OBJECTIVE To estimate the bleeding risk of combined anticoagulant (rivaroxaban or enoxaparin-vitamin K antagonist [VKA]) and NSAID or aspirin therapy in patients with venous thromboembolism.DESIGN, SETTING, AND PARTICIPANTS Prospective analysis of observational data from the EINSTEIN deep vein thrombosis and pulmonary embolism clinical trials comparing rivaroxaban with enoxaparin-VKA treatment, trials performed in hospitals and clinics in 8246 patients enrolled from 2007 to 2009.EXPOSURE Bleeding event rates during exposure to NSAID and aspirin therapy were compared to time without exposure.MAIN OUTCOMES AND MEASURES Days of NSAID or aspirin use and nonuse, clinically relevant bleeding event and major bleeding event rates by patient-years, and hazard ratios.RESULTS During NSAID-anticoagulant concomitant treatment, clinically relevant bleeding occurred with an event rate of 37.5 per 100 patient-years vs 16.6 per 100 patient-years during anticoagulant use only (hazard ratio [HR], 1.77 [95% CI, 1.46-2.14]). Major bleeding during NSAID-anticoagulant treatment occurred with an event rate of 6.5 per 100 patient-years, compared to 2.0 per 100 patient-years during nonuse (HR, 2.37 [95% CI, 1.51-3.75]). For aspirin-anticoagulant concomitant treatment, clinically relevant bleeding occurred with an event rate of 36.6 per 100 patient-years, compared to 16.9 per 100 patient-years during aspirin nonuse (HR, 1.70 [95% CI, 1.38-2.11]). Major bleeding in aspirin-anticoagulant-treated patients occurred with an event rate of 4.8 per 100 patient-years, compared to 2.2 per 100 patient-years during aspirin nonuse (HR, 1.50 [95% CI, 0.86-2.62]). Increases in risk for clinically relevant and major bleeding were similar for rivaroxaban and enoxaparin-VKA anticoagulation regimens.CONCLUSIONS AND RELEVANCE Among patients with venous thromboembolism receiving anticoagulant therapy, concomitant use of an NSAID or aspirin is associated with an increased risk of clinically relevant and major bleeding.

The phase III EINSTEIN DVT and EINSTEIN PE trials demonstrated the potential of oral rivaroxaban for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). The length of initial hospitalization in patients presenting with either symptomatic DVT or PE was assessed using hospitalization records from these trials.Analyses were carried out in the intention-to-treat population, using non-parametric and parametric statistical methods.Overall, 52% (1781/3434) of EINSTEIN DVT patients and 90% (4328/4821) of EINSTEIN PE patients were admitted to hospital. The proportion of hospitalized patients with a length of stay of five or fewer days receiving rivaroxaban was 54% compared with 31% for enoxaparin/vitamin K antagonist (VKA) in patients with DVT. For patients with PE, the corresponding values were 45% and 33%. Stays of 6-10 days were observed in 29% of rivaroxaban-treated patients compared with 45% of enoxaparin/VKA-treated patients for DVT. For patients with PE, these values were 39% and 46% in the rivaroxaban and enoxaparin/VKA groups, respectively. Overall, length of stay was significantly shorter in the rivaroxaban group, compared with the enoxaparin/VKA group across all analyses performed (p 0.0001). Across regions, the observed admission rates and length of stay duration varied greatly: Asia had the longest overall hospitalization rates, whereas the lowest rates were reported in North America, Australia and New Zealand. Nevertheless, a consistent trend was observed: length of hospital stay in patients with DVT or PE receiving rivaroxaban was shorter than, or at least similar to, patients receiving enoxaparin/VKA.A single-drug regimen with rivaroxaban may reduce the burden on healthcare systems and patients, and provides effective and well tolerated treatment. The studies shared an open-label design that allowed comparison of initial hospitalization, but limitations include the well monitored clinical trial setting in which decisions on admission and discharge could vary from real-world management.