Abstract: Background The MARINER trial evaluated whether postdischarge thromboprophylaxis with rivaroxaban could reduce the primary outcome of symptomatic venous thromboembolism (VTE) or VTE-related death in acutely ill medical patients at risk for VTE. Although aspirin use was not randomized, approximately half of the enrolled patients were receiving aspirin at baseline. We hypothesized that thromboprophylaxis with once-daily rivaroxaban (10 mg or, if creatinine clearance was 30–49 mL/min, 7.5 mg) plus aspirin (R/A) would be superior to placebo without aspirin (no thromboprophylaxis [no TP] ). Methods We compared the primary and major secondary outcomes in the intention-to-treat population in four subgroups defined at baseline: (1) R/A (N = 3,159); (2) rivaroxaban alone (N = 2,848); (3) aspirin alone (N = 3,046); and (4) no TP (N = 2,966). Major bleeding (MB) and nonmajor clinically relevant (NMCR) bleeding were assessed in the safety population on treatment plus 2 days. Results Patients on R/A had reduced symptomatic VTE and VTE-related death compared with no TP (0.76 vs 1.28%, p = 0.042), and experienced less symptomatic VTE and all-cause mortality (p = 0.005) and all-cause mortality alone (p = 0.01) compared with no TP. Event incidences for rivaroxaban alone (0.91%) or aspirin alone (0.92%) were similar. MB was low in all groups but lowest in the no TP group. NMCR bleeding was increased with R/A compared with no TP (p = 0.009). Limitations Aspirin use was not randomized. Conclusion Extended postdischarge thromboprophylaxis with R/A was associated with less symptomatic VTE and VTE-related death compared with no TP in previously hospitalized medical patients at risk for VTE. NMCR bleeding was increased with R/A compared with no TP. These post hoc findings need confirmation in a prospective trial.

Abstract: Direct oral anticoagulants simplify venous thromboembolism (VTE) treatment by obviating the need for coagulation monitoring. Nonetheless, renal function, body weight and P-glycoprotein inhibitors influence drug levels. The objective of this analysis was to determine whether reduction in edoxaban dose based on clinical criteria avoids excess drug exposure and preserves efficacy and safety in the Hokusai-VTE study. After initial heparin, patients received edoxaban or warfarin for 3-12 months. Edoxaban was given once daily at a dose of 60 mg, which was reduced to 30 mg in patients with a creatinine clearance of 30–50 ml/minute, body weight ≤60 kg or receiving certain P-glycoprotein inhibitors. The primary efficacy outcome was recurrent VTE and the principal safety outcome was major or clinically relevant non-major bleeding. A total of 8292 patients with acute VTE were randomised, 733 and 719 patients in the edoxaban and warfarin groups met the criteria for dose reduction. These patients were older, more often female or Asian and had more extensive VTE. Edoxaban levels were lower in the 30 mg edoxaban group. Rates of recurrent VTE and bleeding with the 30 mg and 60 mg edoxaban dose were comparable: VTE rates were 3.0 % and 3.2 % and clinically relevant bleeding rates were 7.9 % and 8.6 %, respectively. Rates of recurrent VTE and bleeding in the warfarin-treated patients meeting the criteria for dose reduction were 4.2 % and 12.8 %, respectively. The reduced dose edoxaban regimen maintained efficacy and safety compared with the 60 mg dose but was safer than warfarin in patients meeting the criteria for dose reduction. Supplementary Material to this article is available online at www.thrombosis-online.com.

Abstract: Coronavirus disease 2019 (COVID-19), currently a worldwide pandemic, is a viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The suspected contribution of thrombotic events to morbidity and mortality in COVID-19 patients has prompted a search for novel potential options for preventing COVID-19-associated thrombotic disease. In this article by the Global COVID-19 Thrombosis Collaborative Group, we describe novel dosing approaches for commonly used antithrombotic agents (especially heparin-based regimens) and the potential use of less widely used antithrombotic drugs in the absence of confirmed thrombosis. Although these therapies may have direct antithrombotic effects, other mechanisms of action, including anti-inflammatory or antiviral effects, have been postulated. Based on survey results from this group of authors, we suggest research priorities for specific agents and subgroups of patients with COVID-19. Further, we review other agents, including immunomodulators, that may have antithrombotic properties. It is our hope that the present document will encourage and stimulate future prospective studies and randomized trials to study the safety, efficacy, and optimal use of these agents for prevention or management of thrombosis in COVID-19.

Abstract: Background: Venous thromboembolism (VTE) is common after hospitalization in acutely ill medical patients, yet extended thromboprophylaxis has not been widely implemented due to concerns about bleeding. The MARINER study (NCT02111564) compared thromboprophylaxis with rivaroxaban (10mg daily or 7.5mg daily in subjects with creatinine clearance 30- & lt;50ml/min at baseline) vs placebo for 45 days beyond hospital discharge to prevent symptomatic VTE in acutely ill medical patients while reducing bleeding events through patient selection (Spyropoulos AC et al NEJM 2018). Rivaroxaban did not significantly lower the composite of symptomatic VTE and VTE-related death but reduced symptomatic VTE (0.18% vs 0.42%, p=0.023). While major bleeding (MB) was infrequent in both study groups (0.28% vs 0.15% with rivaroxaban vs. placebo, p=0.124), there was more non-major clinically relevant bleeding (NMCRB) with rivaroxaban (1.42% vs 0.85%, HR 1.66, 95%CI 1.17-2.35, p=0.004). Although MB has been associated with increased mortality, the relationship between NMCRB and all-cause mortality (ACM) is not established. We hypothesized that subjects in the MARINER trial with MB but not those with NMCRB would be at an increased risk of ACM irrespective of treatment group. Methods: We evaluated all bleeding events in subjects taking at least one dose of study drug from randomization until 2 days after the last dose (safety population) and their association with ACM through the Day 75 visit in 3 mutually exclusive groups: (1) subjects with no MB or NMCRB; (2) subjects whose first event was NMCRB; and (3) subjects whose first event was MB. Subjects only developing minimal or trivial bleeding were grouped with those who had no bleeding. Using a Cox proportional hazards model that included the bleeding group variable and baseline covariates that were significantly associated with ACM at p & lt;0.05 (age, sex, history of VTE, history of anemia), we compared the risk of ACM in subjects with and without bleeding events. Results: The incidence of ACM among subjects who had a NMCRB was not increased over that in subjects without bleeding (2/136, 1.5% vs 218/11800, 1.8%, HR 0.41 95%CI 0.10, 1.67, p=0.213), while those experiencing MB had a higher incidence of death (4/26, 15.4% vs 218/11800, 1.8%, HR 3.43 95%CI 1.23, 9.54, p=0.018). Results of landmark analyses from the first bleeding event or end of treatment + 2 days to ACM for the three groups are displayed (Figure). Limitations: This analysis was post hoc and the MARINER trial excluded subjects at a high risk of bleeding. Conclusion: Although few subjects had MB events, those who did had an increased risk of ACM, while those who had NMCRB events did not. This suggests that the modest increase in NMCRB in trials of extended thromboprophylaxis may be an acceptable tradeoff to prevent VTE. Disclosures Spyropoulos: Janssen R & D, LLC: Consultancy; ATLAS (Colorado Prevention Center): Consultancy; Bayer Healthcare: Consultancy; Portola: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding; Daiichi Sankyo: Consultancy. Ageno:Bayer: Membership on an entity's Board of Directors or advisory committees, Other: research support,travel support ; BMS Pfizer: Other: travel support; Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees, Other: conference and travel support; Portola: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Aspen: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees, Other: travel support. Albers:Janssen R & D, LLC: Consultancy; Bayer Healthcare: Consultancy. Elliott:Bayer Healthcare: Consultancy; University of Cincinnati: Honoraria; Spectrum Health: Honoraria; Janssen R & D, LLC: Consultancy. Halperin:Ortho-McNeil-Janssen: Consultancy; Johnson & Johnson: Consultancy; ATLAS (Colorado Prevention Center): Consultancy; NIH: Consultancy; Pfizer: Consultancy; Daiichi Sankyo: Consultancy; Boehringer Ingelheim: Consultancy. Hiatt:Bayer Healthcare: Consultancy; NIH: Research Funding; Janssen R & D, LLD: Consultancy. Maynard:Janssen R & D, LLC: Consultancy. Steg:Novartis: Consultancy; Regeneron: Consultancy; Lilly: Consultancy; Pfizer: Consultancy; Boehringer Ingelheim: Consultancy; Bristol-Myers Squibb: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Amarin: Consultancy; Servier: Consultancy, Research Funding; Merck: Research Funding, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Bayer Healthcare: Consultancy, Research Funding; Janssen R & D, LLC: Consultancy, Research Funding; AstraZeneca: Consultancy. Weitz:Novartis: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Ionis: Consultancy, Honoraria; Daiichi-Sankyo: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Boehringer Ingelheim: Consultancy, Honoraria; Bayer Healthcare: Consultancy, Honoraria; Janssen R & D, LLC: Consultancy; Pfizer: Consultancy, Honoraria; Portola: Consultancy, Honoraria. Spiro:Bayer U.S. LLC: Employment, Equity Ownership. Lu:Janssen R & D, LLC: Employment, Equity Ownership. Sugarmann:Janssen Research and Development LLC: Employment, Equity Ownership. Lipardi:Janssen Research and Develompent: Employment, Equity Ownership. Raskob:Boehringer Ingelheim: Consultancy; Eli Lilly: Consultancy; Pfizer: Consultancy, Honoraria; Tetherex: Consultancy; Daiichi Sankyo: Consultancy, Honoraria; Anthos: Consultancy; BMS: Consultancy, Honoraria; Janssen R & D, LLC: Consultancy, Honoraria; Portola: Consultancy; Novartis: Consultancy; Bayer Healthcare: Consultancy, Honoraria. Barnathan:Janssen Research and Development LLC: Employment, Equity Ownership. OffLabel Disclosure: Rivaroxaban is a Factor Xa inhibitor. The study evaluated the efficacy and safety of rivaroxaban post-hospitalization in subjects with an acute medical illness as thromboprophylaxis for venous thromboembolism.

Abstract: Background: Venous thromboembolism (VTE) is common after hospitalization in acutely ill medical patients, yet extended thromboprophylaxis has not been widely implemented due to concerns about bleeding. The MAGELLAN study (NCT00571649) evaluated whether rivaroxaban (10 mg QD for 35±4 days) compared with enoxaparin (40 mg QD for 10±4 days) followed by placebo could prevent asymptomatic deep vein thrombosis, symptomatic VTE, and VTE-related death. Through Day 35, rivaroxaban was superior to enoxaparin/placebo in the modified intent-to-treat population (4.4% vs 5.7%, RR 0.77, 95%CI, 0.62 to 0.96, p=0.02), but there was an increase in clinically relevant bleeding, the composite of major and non-major clinically relevant (NMCR) bleeding (4.1% vs 1,7%, RR 2.5, 95%CI 1.85-3.25, p 〈 0.001). Although major bleeding has been associated with increased mortality, the relationship between NMCR bleeding and all-cause mortality (ACM) is not established. We hypothesized that subjects in the MAGELLAN trial with major bleeding but not those with NMCR bleeding, would be at an increased risk of ACM irrespective of treatment group. Methods: We evaluated all bleeding events in subjects taking at least one dose of study drug from randomization until 2 days after the last dose (safety population) and their association with ACM through the Day 90 visit in 3 mutually exclusive groups: (1) subjects with no major or NMCR bleeding; (2) subjects whose first event was NMCR bleeding; and (3) subjects whose first event was major bleeding. Subjects only developing minimal or trivial bleeding were grouped with those who had no clinically relevant bleeding. Using a Cox proportional hazards model that included the bleeding group variable and baseline covariates significantly associated with ACM at p 〈 0.05 (age, BMI, history of cancer, history of anemia, inflammatory disease, acute ischemic stroke, and acute respiratory insufficiency), we compared the risk of ACM in subjects with and without bleeding events. Results: The incidence of ACM for subjects who had NMCR bleeding was numerically higher but not significantly increased compared with subjects with no bleeding (20/176, 11.4% vs 468/7763, 6.0%, HR 1.41 95%CI 0.88, 2.25, p=0.151), while subjects with major bleeding were at a significantly increased risk of death (28/59, 47.5% vs 468/7763, 6.0%, HR 7.74 95%CI 5.16, 11.59, p 〈 0.0001). Results of landmark analyses from the first bleeding event or end of treatment + 2 days to ACM for the three groups are displayed (Figure). Limitations: This analysis was post hoc and may have been underpowered to detect differences in ACM associated with NMCR bleeding. Conclusion: Major bleeding was associated with a significantly increased risk of ACM but NMCR bleeding was not. This suggests that a modest increase in NMCR bleeding associated with extended thromboprophylaxis with rivaroxaban may be acceptable to prevent VTE. Strategies to better select patients at lower risk of bleeding may improve the benefit risk profile of extended thromboprophylaxis with rivaroxaban. Disclosures Spyropoulos: Daiichi Sankyo: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding; Portola: Consultancy; Bayer Healthcare: Consultancy; ATLAS (Colorado Prevention Center): Consultancy; Janssen R & D, LLC: Consultancy. Raskob:Janssen R & D, LLC: Consultancy, Honoraria; Novartis: Consultancy; Tetherex: Consultancy; Daiichi Sankyo: Consultancy, Honoraria; Anthos: Consultancy; Boehringer Ingelheim: Consultancy; Pfizer: Consultancy, Honoraria; Portola: Consultancy; Bayer Healthcare: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Eli Lilly: Consultancy. Cohen:Boston Scientific: Consultancy; CSL Behring: Consultancy; GlaxoSmithKline: Consultancy, Speakers Bureau; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Boehringer-Ingelheim: Consultancy, Speakers Bureau; GLG: Consultancy; AbbVie: Consultancy; ACI Clinical: Consultancy; Aspen: Consultancy, Speakers Bureau; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Guidepoint Global: Consultancy; Johnson and Johnson: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Leo Pharma: Consultancy; Medscape: Consultancy, Speakers Bureau; McKinsey: Consultancy; Navigant: Consultancy; ONO: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Temasek Capital: Consultancy; TRN: Consultancy; UK Government Health Select Committee: Other: advised the UK Government Health Select Committee, the all-party working group on thrombosis, the Department of Health, and the NHS, on the prevention of VTE; Lifeblood: Other: advisor to Lifeblood: the thrombosis charity and is the founder of the European educational charity the Coalition to Prevent Venous Thromboembolism. Ageno:Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees, Other: conference and travel support; Bayer: Membership on an entity's Board of Directors or advisory committees, Other: research support,travel support ; BMS Pfizer: Other: travel support; Aspen: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Portola: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees, Other: travel support; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: travel support. Weitz:Janssen R & D, LLC: Consultancy; Bayer Healthcare: Consultancy, Honoraria; Boehringer Ingelheim: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Daiichi-Sankyo: Consultancy, Honoraria; Ionis: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Portola: Consultancy, Honoraria. Spiro:Bayer U.S. LLC: Employment, Equity Ownership. Lu:Janssen R & D, LLC: Employment, Equity Ownership. Lipardi:Janssen Research and Develompent: Employment, Equity Ownership. Barnathan:Janssen Research and Development LLC: Employment, Equity Ownership. OffLabel Disclosure: Rivaroxaban is a Factor Xa inhibitor. It is currently under review by FDA for approval as thromboprophylaxis in acutely ill medical patients at risk for venous thromboembolism.