Treatment of cancer-associated venous thromboembolism: A focus on special populations.

Current evidence-based clinical practice guidelines recommend the use of both low-molecular-weight heparin (LMWH) and direct factor Xa inhibitors (apixapan, edoxaban and rivaroxaban) as first-line options for the treatment of venous thromboembolism (VTE) in patients with cancer. However, most of these guidelines refer to the general cancer patient population and provide limited guidance for specific subgroups of patients at particularly high risk of bleeding, such as those with gastrointestinal cancers, primary or metastatic brain tumors, thrombocytopenia, or renal impairment. In these complex populations, the management of cancer-associated thrombosis (CAT) poses unique challenges and requires a nuanced approach based on the primum non nocere principle. This comprehensive review critically examines the relevant literature and discusses the therapeutic options currently available for the management of CAT in these special situations.

Outcomes of venous thromboembolism care: future directions.

The complete picture of the outcomes of venous thromboembolism (VTE) care consists of conventional binary clinical outcomes (death, recurrent VTE, and bleeding), patient-centered outcomes, and society-level outcomes. Combined, these allow for the introduction of outcome-driven patient-centered health care. The emerging concept of valuing health care from such a holistic point of view, ie, value-based health care, holds a huge potential to revolutionize-and improve-the organization and evaluation of care. The ultimate goal of this approach was to achieve a high value for patients, ie, the best possible clinical outcomes at the right cost, providing a framework for evaluation and comparisons of different management strategies, patient pathways, or even complete health care delivery systems. To facilitate this, outcomes of care from a patient perspective, such as symptom burden, functional limitations, and quality of life, need to be routinely captured in clinical practice and trials, complementary to the conventional clinical outcomes, to fully capture the patients' values and needs. The aim of this review was to discuss the relevant outcomes of VTE care, explore value in VTE care from different perspectives, and propose future directions to inspire change. This is a call to action to shift the focus to outcomes that matter and make a larger difference in the lives of patients.

Direct Oral Anticoagulants for the Prevention and Acute Treatment of Cancer-Associated Thrombosis.

Cancer is a major risk factor for venous thromboembolism (VTE), and cancer-associated thrombosis (CAT) constitutes approximately 15-25% of all VTE cases. For decades, the standard treatment for CAT used to be daily subcutaneous low molecular weight heparin (LMWH). Data on the safety and efficacy of the direct oral anticoagulants (DOACs) in this population emerged only in recent years and specific DOACs were included into recent guidelines recommendations. In this narrative review of the literature, we reported the results of the phase III randomized controlled trials that evaluated the DOACs for the prevention and the acute treatment of CAT. For the acute phase treatment, the anti-Xa inhibitors (apixaban, edoxaban, rivaroxaban) showed better efficacy than LMWH in preventing VTE recurrence; however, rivaroxaban and edoxaban were also associated with an increased risk of bleeding events. For primary prevention of CAT in ambulatory cancer patients starting chemotherapy, apixaban and rivaroxaban showed better efficacy than placebo but a trend towards higher bleeding rates. Recent guidelines suggest the DOACs for the treatment of CAT in selected cancer patients (eg, low bleeding risk, no luminal gastrointestinal or genitourinary malignancies, no interfering medications). The DOACs are also suggested for primary thromboprophylaxis in selected ambulatory cancer patients at high risk of VTE (eg, Khorana score ≥2 prior to starting new chemotherapy, low bleeding risk, no interfering medications).

Effect of polypharmacy on bleeding with rivaroxaban versus vitamin K antagonist for treatment of venous thromboembolism.

BACKGROUND: Polypharmacy, including use of inhibitors of CYP3A4 and P-glycoprotein (P-gp), is common in patients with venous thromboembolism (VTE) and is associated with increased bleeding. METHODS: In 8246 patients included in the EINSTEIN-VTE studies for acute VTE, we evaluated the effect of polypharmacy on bleeding and on the relative differences between rivaroxaban and enoxaparin/vitamin K antagonist (VKA). We assessed the incidence of clinically relevant bleeding (major and clinically relevant nonmajor bleeding) by number of comedications (none, 1-3, ≥4) at baseline, and by use of CYP3A4 and/or P-gp inhibitors. Interaction between rivaroxaban versus enoxaparin/VKA and comedication was assessed by Cox regression analysis with pinteraction estimates. RESULTS: With increasing number of comedications, the incidence of clinically relevant bleeding rose from 5.7% to 13.3% in rivaroxaban recipients and from 9.1% to 11.1% in enoxaparin/VKA recipients. Whereas rivaroxaban was associated with a reduced bleeding risk compared with enoxaparin/VKA in patients without comedication (hazard ratio [HR] 0.6, 95% confidence interval [CI] 0.4-0.9), the risk was similar in patients with ≥4 comedications (HR 1.2, 95% CI 0.97-1.5, pinteraction .002). Use of CYP3A4 and/or P-gp inhibitors was associated with a doubled bleeding risk compared with no use, without a difference between rivaroxaban and enoxaparin/VKA. CONCLUSION: We conclude that fixed-dose rivaroxaban as compared with enoxaparin followed by dose-adjusted VKA is not associated with an increased bleeding risk in patients with VTE administered polypharmacy in general and CYP3A4 and/or P-gp inhibitors specifically. This implies that the observed increased bleeding risks with polypharmacy and use of CYP3A4 and/or P-gp inhibitors are likely explained by comorbidities and frailty, and not by pharmacokinetic interactions.

Effectiveness and Safety of Oral Anticoagulants in the Treatment of Acute Venous Thromboembolism: A Nationwide Comparative Cohort Study in France.

INTRODUCTION: Data from clinical trials indicate that direct oral anticoagulants (DOACs) are noninferior and safer than conventional therapy (low-molecular-weight heparin followed by a vitamin K antagonist [VKA]) for treating venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism (PE). This study compared the effectiveness and safety of DOACs and conventional therapy in a real-world setting. METHODS: This observational study used French national claims data of adult, treatment-naïve patients diagnosed with VTE (majority PE) who were hospitalized and treated for VTE with a DOAC (apixaban or rivaroxaban) or VKAs during 2013 to 2018. Patients with active cancer were excluded. After propensity score matching for each DOAC-VKA comparison, risks of bleeding, recurrent VTE, and all-cause mortality were compared at 6 months. Cox proportional hazards regression was used to estimate adjusted hazard ratios of the endpoints. RESULTS: A total of 58,137 patients were included (10,775 VKAs, 10,440 apixaban, 36,922 rivaroxaban). Propensity score-matched cohort sizes were 7,503 for apixaban and 9,179 for rivaroxaban. The hazard ratio (95% confidence interval) was significantly lower for apixaban than VKAs for bleeding requiring hospitalization (0.43 [0.32-0.59]), all-cause death (0.61 [0.51-0.74]), and first recurrent VTE (0.67 [0.52-0.85]). The hazard ratio was also significantly lower for rivaroxaban than VKAs for all-cause death (0.63 [0.53-0.74]) but not for bleeding requiring hospitalization (0.86 [0.69-1.07]) or first recurrent VTE (0.91 [0.74-1.13]). CONCLUSION: Apixaban was associated with superior safety and effectiveness than VKAs. All-cause mortality was lower in both DOACs than VKAs. Our results support recommendations to use DOACs over VKAs for the treatment of VTE.

Statins for venous event reduction in patients with venous thromboembolism: A multicenter randomized controlled pilot trial assessing feasibility.

BACKGROUND: Statins may reduce the risk for recurrent venous thromboembolism (VTE); however, no randomized trials have explored this hypothesis. We performed a pilot randomized trial to determine feasibility of recruitment for a larger trial of secondary VTE prevention with rosuvastatin. METHODS: Patients with a newly diagnosed symptomatic proximal deep vein thrombosis and/or pulmonary embolism, receiving standard anticoagulation, were randomly allocated to adjuvant rosuvastatin 20 mg once daily for 180 days or no rosuvastatin for 6 months. RESULTS: Between November 2016 and December 2019, 3391 patients were assessed for eligibility in six centers. Of these patients, 1347 (39.7%) were eligible and approached for participation in the trial and 312 (23.1%) were randomized. The mean rate of randomization was 8.2 ± 4.3 patients per month. During follow-up, five recurrent VTE events were observed, three (1.9%) in the rosuvastatin group (two pulmonary embolism, one deep vein thrombosis), and two (1.3%) in the control group (two pulmonary embolism; P = 0.68). One major arterial event occurred in the rosuvastatin arm and none in the control arm (0.6% vs. 0%, P = 0.50). CONCLUSION: This pilot trial supports the feasibility of a larger scale randomized controlled trial to determine the efficacy of adjuvant rosuvastatin for the secondary prevention of VTE.

Extended Anticoagulant Treatment with Full- or Reduced-Dose Apixaban in Patients with Cancer-Associated Venous Thromboembolism: Rationale and Design of the API-CAT Study.

Cancer-associated thrombosis (CT) is associated with a high risk of recurrent venous thromboembolic (VTE) events that require extended anticoagulation in patients with active cancer, putting them at risk of bleeding. The aim of the API-CAT study (NCT03692065) is to assess whether a reduced-dose regimen of apixaban (2.5 mg twice daily [bid]) is noninferior to a full-dose regimen of apixaban (5 mg bid) for the prevention of recurrent VTE in patients with active cancer who have completed ≥6 months of anticoagulant therapy for a documented index event of proximal deep-vein thrombosis and/or pulmonary embolism. API-CAT is an international, randomized, parallel-group, double-blind, noninferiority trial with blinded adjudication of outcome events. Consecutive patients are randomized to receive apixaban 2.5 or 5 mg bid for 12 months. The primary efficacy outcome is a composite of recurrent symptomatic or incidental VTE during the treatment period. The principal safety endpoint is clinically relevant bleeding, defined as a composite of major bleeding or nonmajor clinically relevant bleeding. Assuming a 12-month incidence of the primary outcome of 4% with apixaban and an upper limit of the two-sided 95% confidence interval of the hazard ratio <2.0, 1,722 patients will be randomized, assuming an up to 10% loss in total patient-years (ß = 80%; α one-sided = 0.025). This trial has the potential to demonstrate that a regimen of extended treatment for patients with CT beyond an initial 6 months, with a reduced apixaban dose, has an acceptable risk of recurrent VTE recurrence and decreases the risk of bleeding.

Thromboembolic and bleeding complications following primary total knee arthroplasty : a Danish nationwide cohort study.

AIMS: The aim of this study is to compare the effectiveness and safety of thromboprophylactic treatments in patients undergoing primary total knee arthroplasty (TKA). METHODS: Using nationwide medical registries, we identified patients with a primary TKA performed in Denmark between 1 January 2013 and 31 December 2018 who received thromboprophylactic treatment. We examined the 90-day risk of venous thromboembolism (VTE), major bleeding, and all-cause mortality following surgery. We used a Cox regression model to compute hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome, pairwise comparing treatment with dalteparin or dabigatran with rivaroxaban as the reference. The HRs were both computed using a multivariable and a propensity score matched analysis. RESULTS: We identified 27,736 primary TKA patients who received thromboprophylactic treatment (rivaroxaban (n = 18,846); dalteparin (n = 5,767); dabigatran (n = 1,443); tinzaparin (n = 1,372); and enoxaparin (n = 308)). In the adjusted multivariable analysis and compared with rivaroxaban, treatment with dalteparin (HR 0.68 (95% CI 0.49 to 0.92)) or dabigatran (HR 0.31 (95% CI 0.13 to 0.70)) was associated with a decreased risk of VTE. No statistically significant differences were observed for major bleeding or all-cause mortality. The propensity score matched analysis yielded similar results. CONCLUSION: Treatment with dalteparin or dabigatran was associated with a decreased 90-day risk of VTE following primary TKA surgery compared with treatment with rivaroxaban. Cite this article: Bone Joint J 2021;103-B(10):1571-1577.

Monotherapy Anticoagulation to Expedite Home Treatment of Patients Diagnosed With Venous Thromboembolism in the Emergency Department: A Pragmatic Effectiveness Trial.

BACKGROUND: The objective was to test if low-risk emergency department patients with vitamin K antagonist (venous thromboembolism [VTE]; including venous thrombosis and pulmonary embolism [PE]) can be safely and effectively treated at home with direct acting oral (monotherapy) anticoagulation in a large-scale, real-world pragmatic effectiveness trial. METHODS: This was a single-arm trial, conducted from 2016 to 2019 in accordance with the Standards for Reporting Implementation Studies guideline in 33 emergency departments in the United States. Participants had newly diagnosed VTE with low risk of death based upon either the modified Hestia criteria, or physician judgment plus the simplified PE severity index score of zero, together with nonhigh bleeding risk were eligible. Patients had to be discharged within 24 hours of triage and treated with either apixaban or rivaroxaban. Effectiveness was defined by the primary efficacy and safety outcomes, image-proven recurrent VTE and bleeding requiring hospitalization >24 hours, respectively, with an upper limit of the 95% CI for the 30-day frequency of VTE recurrence below 2.0% for both outcomes. RESULTS: We enrolled 1421 patients with complete outcomes data, including 903 with venous thrombosis and 518 with PE. The recurrent VTE requiring hospitalization occurred in 14/1421 (1.0% [95% CI, 0.5%-1.7%]), and bleeding requiring hospitalization occurred in 12/1421 (0.8% [0.4%-1.5%). The rate of severe bleeding using International Society for Thrombosis and Haemostasis criteria was 2/1421 (0.1% [0%-0.5%]). No patient died, and serious adverse events occurred in 2.5% of venous thrombosis patients and 2.3% of patients with PE. Medication nonadherence was reported by patients in 8.0% (6.6%-9.5%) and was associated with a risk ratio of 6.0 (2.3-15.2) for VTE recurrence. Among all patients diagnosed with VTE in the emergency department during the period of study, 18% of venous thrombosis patients and 10% of patients with PE were enrolled. CONCLUSIONS: Monotherapy treatment of low-risk patients with venous thrombosis or PE in the emergency department setting produced a low rate of bleeding and VTE recurrence, but may be underused. Patients with venous thrombosis and PE should undergo risk-stratification before home treatment. Improved patient adherence may reduce rate of recurrent VTE. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03404635.

The safety and effectiveness of salvianolate in preventing perioperative venous thromboembolism in China: A PRISMA-compliant meta-analysis based on RCTs.

BACKGROUND: Salvianolate, a common drug for stabilizing heart disease and Angina Pectoris, is considered to be off-label for preventing venous thromboembolism (VTE) or anticoagulation at present. However, many clinical studies have showed that salvianolate can effectively inhibit the deep-vein thrombosis (DVT) incidence, and prevent VTE of perioperative patients in the real world in China. OBJECTIVE: This analysis aimed to evaluate the effectiveness and safety of salvianolate in preventing VTE in perioperative patients. METHODS: Databases of PubMed, Cochrane Library, Embase, CNKI, Wanfang and VIP were searched until July 2019. Literature retrieval, data extraction and quality assessment were independently completed by two researchers and checked with each other. Review Manager 5.2 software was applied for meta-analysis. RESULTS: A total of 429 studies were retrieved, including 11 randomized controlled trials (RCTs) with a total of 1149 subjects. Compared with low molecular weight heparin (LMWH) group alone, salvianolate combined LMWH group had lower DVT incidence in preventing perioperative thrombosis (2.75% and 14.23%, OR: 0.21, 95% CI:[0.08,0.53]; P = .0009). The incidence of adverse reactions of experimental group was similar to that of control group (1.79% and 2.31%, OR: 0.65, 95% CI:[0.18,2.35]. P = .51). Compared with the control group, D-dimer level (D-D), platelet count (PLT), fibrinogen (FIB), whole blood high shear viscosity (WBHSV), and whole blood low shear viscosity (WBLSV) were all significantly decreased (P < .01), and prothrombin time (PT) was significantly increased (P < .05). CONCLUSION: Salvianolate combined LMWH has better effectiveness and the same safety in preventing venous thromboembolism in perioperative patients. However, due to the small number of included literatures, large sample studies are still needed to further verify this conclusion.

Natural Language Processing Performance for the Identification of Venous Thromboembolism in an Integrated Healthcare System.

Real-time identification of venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) and pulmonary embolism (PE), can inform a healthcare organization's understanding of these events and be used to improve care. In a former publication, we reported the performance of an electronic medical record (EMR) interrogation tool that employs natural language processing (NLP) of imaging studies for the diagnosis of venous thromboembolism. Because we transitioned from the legacy electronic medical record to the Cerner product, iCentra, we now report the operating characteristics of the NLP EMR interrogation tool in the new EMR environment. Two hundred randomly selected patient encounters for which the imaging report assessed by NLP that revealed VTE was present were reviewed. These included one hundred imaging studies for which PE was identified. These included computed tomography pulmonary angiography-CTPA, ventilation perfusion-V/Q scan, and CT angiography of the chest/ abdomen/pelvis. One hundred randomly selected comprehensive ultrasound (CUS) that identified DVT were also obtained. For comparison, one hundred patient encounters in which PE was suspected and imaging was negative for PE (CTPA or V/Q) and 100 cases of suspected DVT with negative CUS as reported by NLP were also selected. Manual chart review of the 400 charts was performed and we report the sensitivity, specificity, positive and negative predictive values of NLP compared with manual chart review. NLP and manual review agreed on the presence of PE in 99 of 100 cases, the presence of DVT in 96 of 100 cases, the absence of PE in 99 of 100 cases and the absence of DVT in all 100 cases. When compared with manual chart review, NLP interrogation of CUS, CTPA, CT angiography of the chest, and V/Q scan yielded a sensitivity = 93.3%, specificity = 99.6%, positive predictive value = 97.1%, and negative predictive value = 99%.

Prevalence and Predictors of Venous Thromboembolism or Mortality in Hospitalized COVID-19 Patients.

BACKGROUND: We aimed to identify the prevalence and predictors of venous thromboembolism (VTE) or mortality in hospitalized coronavirus disease 2019 (COVID-19) patients. METHODS: A retrospective cohort study of hospitalized adult patients admitted to an integrated health care network in the New York metropolitan region between March 1, 2020 and April 27, 2020. The final analysis included 9,407 patients with an overall VTE rate of 2.9% (2.4% in the medical ward and 4.9% in the intensive care unit [ICU]) and a VTE or mortality rate of 26.1%. Most patients received prophylactic-dose thromboprophylaxis. Multivariable analysis showed significantly reduced VTE or mortality with Black race, history of hypertension, angiotensin converting enzyme/angiotensin receptor blocker use, and initial prophylactic anticoagulation. It also showed significantly increased VTE or mortality with age 60 years or greater, Charlson Comorbidity Index (CCI) of 3 or greater, patients on Medicare, history of heart failure, history of cerebrovascular disease, body mass index greater than 35, steroid use, antirheumatologic medication use, hydroxychloroquine use, maximum D-dimer four times or greater than the upper limit of normal (ULN), ICU level of care, increasing creatinine, and decreasing platelet counts. CONCLUSION: In our large cohort of hospitalized COVID-19 patients, the overall in-hospital VTE rate was 2.9% (4.9% in the ICU) and a VTE or mortality rate of 26.1%. Key predictors of VTE or mortality included advanced age, increasing CCI, history of cardiovascular disease, ICU level of care, and elevated maximum D-dimer with a cutoff at least four times the ULN. Use of prophylactic-dose anticoagulation but not treatment-dose anticoagulation was associated with reduced VTE or mortality.

Impact of oral anticoagulation choice on healthcare utilization for the primary treatment of venous thromboembolism.

Little is known about the impact of oral anticoagulation (OAC) choice on healthcare encounters during venous thromboembolism (VTE) primary treatment. Among anticoagulant-naïve patients with VTE, we tested the hypotheses that healthcare utilization would be lower among users of direct OACs (DOACs; rivaroxaban or apixaban) than among users of warfarin. MarketScan databases for years 2016 and 2017 were used; healthcare utilization was identified in the first 6 months after initial VTE diagnoses. The 23,864 patients with VTE had on average 0.2 ± 0.5 hospitalizations, spent 1.3 ± 5.2 days in the hospital, had 5.7 ± 5.1 outpatient encounters, and visited an emergency department 0.4 ± 1.1 times. As compared to warfarin, rivaroxaban and apixaban were associated with fewer hospitalizations, days hospitalized, outpatient office visits, and emergency department visits after accounting for age, sex, comorbidities, and medications. Hospitalization rates were 24% lower (incidence rate ratio (IRR): 0.76; 95% CI: 0.69, 0.83) with rivaroxaban and 22% lower (IRR: 0.78; 95% CI: 0.71, 0.87) with apixaban, as compared to warfarin (IRR: 1.00 (reference)). Healthcare utilization was similar between apixaban and rivaroxaban users. Patients with VTE prescribed rivaroxaban and apixaban had lower healthcare utilization than those prescribed warfarin, while there was no difference when comparing apixaban to rivaroxaban. These findings complement existing literature supporting the use of DOACs over warfarin.

Effectiveness and safety of apixaban and rivaroxaban for acute venous thromboembolism therapy in patients with extremes in bodyweight.

OBJECTIVES: To investigate the association of extremes in bodyweight (EBW) and outcomes in patients with acute venous thromboembolism (VTE). Recurrent VTE, major bleeding, and clinically relevant non-major bleeding were compared between patients with bodyweight <60 kg, 60-120 kg, and >120 kg. METHODS: Consecutive patients enrolled in the Mayo Clinic VTE Registry (03/28/2013-8/31/2019) with acute VTE were followed prospectively. Patient status was assessed in person, by mailing a written questionnaire, or by a scripted phone interview. RESULTS: Among 2577 patients with weight ranging from 27.0 kg to 263.2 kg, 2123 (82%) had a bodyweight between 60 and 120 kg, 223 (8.7%) had bodyweight < 60 kg, and 230 (8.9%) had bodyweight >120 kg. Patients with bodyweight <60 kg treated with DOACs had higher 3- and 6-month incidence of major bleeding compared to the bodyweight 60-120kg group (4.4% vs 1.1%, P = .03, and 4.4% vs 1.4%, P = .05, respectively). Patients with bodyweight >120 kg and cancer on rivaroxaban had higher VTE recurrence compared to bodyweight 60-120kg group (P = .01). CONCLUSIONS: Treatment of acute VTE is associated with a higher incidence of bleeding in patients with bodyweight <60 kg. A higher VTE recurrence rate occurred only in cancer patients with bodyweight >120 kg on rivaroxaban.

Associations between model-predicted rivaroxaban exposure and patient characteristics and efficacy and safety outcomes in the treatment of venous thromboembolism.

Anticoagulant plasma concentrations and patient characteristics might affect the benefit-risk balance of therapy. This study assessed the impact of model-predicted rivaroxaban exposure and patient characteristics on outcomes in patients receiving rivaroxaban for venous thromboembolism treatment (VTE-T) using data from the phase 3 EINSTEIN-DVT and EINSTEIN-PE studies. In the absence of measured rivaroxaban exposure, exposure estimates were predicted based on individual increases in prothrombin time (PT) and the known correlation between rivaroxaban plasma concentrations and PT dynamics. The composite efficacy outcomes evaluated were recurrent deep-vein thrombosis (DVT) and pulmonary embolism (PE) and recurrent DVT, PE and all-cause death; safety outcomes were major bleeding and the composite of major or non-major clinically relevant (NMCR) bleeding. Exposure-response relationships were evaluated using multivariate logistic and Cox regression for the twice-daily (BID) and once-daily (OD) dosing periods, respectively. Predicted rivaroxaban exposure and CrCl were significantly associated with both efficacy outcomes in the BID period. In the OD period, exposure was significantly associated with recurrent DVT and PE but not recurrent DVT, PE and all-cause death. The statistically significant exposure-efficacy relationships were shallow. Exposure-safety relationships were absent within the investigated exposure range. During both dosing periods, low baseline hemoglobin and prior bleeding were associated with the composite of major or NMCR bleeding. In conclusion, based on the underlying data and analysis, no reliable target window for exposure with improved benefit-risk could be identified within the investigated exposure range. Therefore, monitoring rivaroxaban levels is unlikely to be beneficial in VTE-T.

Rivaroxaban for treatment of pediatric venous thromboembolism. An Einstein-Jr phase 3 dose-exposure-response evaluation.

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 <30, and <12 kg, respectively. Previously, these regimens were confirmed for children weighing ≥20 kg but only predicted in those <20 kg. Based on sparse blood sampling, the daily area under the plasma concentration-time curve [AUC(0-24)ss ] and trough [Ctrough,ss ] and maximum [Cmax,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.