Comparison of rivaroxaban and low molecular weight heparin in the treatment of cancer-associated venous thromboembolism: a Swedish national population-based register study.

BACKGROUND: Treating cancer-associated venous thromboembolism (CAT) with anticoagulation prevents recurrent venous thromboembolism (rVTE), but increases bleeding risk. OBJECTIVES: To compare incidence of rVTE, major bleeding, and all-cause mortality for rivaroxaban versus low molecular weight heparin (LMWH) in patients with CAT. METHODS: We developed a cohort study using Swedish national registers 2013-2019. Patients with CAT (venous thromboembolism within 6 months of cancer diagnosis) were included. Those with other indications or with high bleeding risk cancers were excluded (according to guidelines). Follow-up was from index-CAT until outcome, death, emigration, or end of study. Incidence rates (IR) per 1000 person-years with 95% confidence interval (CI) and propensity score overlap-weighted hazard ratios (HRs) for rivaroxaban versus LMWH were estimated. RESULTS: We included 283 patients on rivaroxaban and 5181 on LMWH. The IR for rVTE was 68.7 (95% CI 40.0-109.9) for rivaroxaban, compared with 91.6 (95% CI 81.9-102.0) for LMWH, with adjusted HR 0.77 (95% CI 0.43-1.35). The IR for major bleeding was 23.5 (95% CI 8.6-51.1) for rivaroxaban versus 49.2 (95% CI 42.3-56.9) for LMWH, with adjusted HR 0.62 (95% CI 0.26-1.49). The IR for all-cause mortality was 146.8 (95% CI 103.9-201.5) for rivaroxaban and 565.6 (95% CI 541.8-590.2) for LMWH with adjusted HR 0.48 (95% CI 0.34-0.67). CONCLUSIONS: Rivaroxaban performed similarly to LMWH for patients with CAT for rVTE and major bleeding. An all-cause mortality benefit was observed for rivaroxaban which potentially may be attributed to residual confounding. TRIAL REGISTRATION NUMBER: NCT05150938 (Registered 9 December 2021).

Comparison of Clinical Outcomes in Patients with Active Cancer Receiving Rivaroxaban or Low-Molecular-Weight Heparin: The OSCAR-UK Study.

BACKGROUND: In most patients with cancer-associated venous thromboembolism (CT), essentially those not at high risk of bleeding, guidelines recommend treatment with direct oral anticoagulants as an alternative to low-molecular-weight heparins (LMWHs). Population-based studies comparing these therapies are scarce. OBJECTIVES: To compare the risk of venous thromboembolism (VTE) recurrences, significant bleeding, and all-cause mortality in patients with CT receiving rivaroxaban or LMWHs. PATIENTS/METHODS: Using UK Clinical Practice Research Datalink data from 2013 to 2020, we generated a cohort of patients with first CT treated initially with either rivaroxaban or LMWH. Patients were observed 12 months for VTE recurrences, significant bleeds (major bleeds or clinically relevant nonmajor bleeding requiring hospitalization), and all-cause mortality. Overlap weighted sub-distribution hazard ratios (SHRs) compared rivaroxaban with LMWH in an intention-to-treat analysis. RESULTS: The cohort consisted of 2,259 patients with first CT, 314 receiving rivaroxaban, and 1,945 LMWH, mean age 72.4 and 66.9 years, respectively. In the 12-month observational period, 184 person-years following rivaroxaban and 1,057 following LMWH, 10 and 66 incident recurrent VTE events, 20 and 102 significant bleeds, and 10 and 133 deaths were observed in rivaroxaban and LMWH users, respectively. The weighted SHR at 12 months for VTE recurrences in rivaroxaban compared with LMWH were 0.80 (0.37-1.73); for significant bleeds 1.01 (0.57-1.81); and for all-cause mortality 0.49 (0.23-1.06). CONCLUSION: Patients with CT, not at high risk of bleeding, treated with either rivaroxaban or LMWH have comparable effectiveness and safety outcomes. This supports the recommendation that rivaroxaban is a reasonable alternative to LMWH for the treatment of CT.

Rivaroxaban Versus Low-Molecular-Weight Heparins in a Broad Cohort of Patients With Cancer-Associated Venous Thromboembolism: An Analysis of the OSCAR-US Program.

Cancer-associated venous thromboembolism (CAT) guidelines recommend direct oral anticoagulants as alternatives to low-molecular-weight heparin (LMWH) in most patients. This study compared the effectiveness and safety of rivaroxaban versus LMWH for a broad CAT cohort. The cohort study used electronic health data from January 2012 to December 2020 to evaluate patients with active cancer experiencing acute venous thromboembolism (VTE) and treated with rivaroxaban or LMWH. Propensity score-overlap weighted hazard ratios (HRs) and 95% confidence intervals (CIs) for VTE, bleeding-related hospitalization, and all-cause mortality were calculated. In total, 4935 patients were identified (27.9% on rivaroxaban and 72.1% on LMWH). The cancer types included gastrointestinal (29.4%), genitourinary (26.2%), lung (24.0%), breast (19.7%), and hematologic (14.4%). Rivaroxaban was associated with a reduction in recurrent VTE versus LMWH among all patients with cancer (HR = 0.78; 95%CI = 0.61-0.99) at 3 months. No differences in bleeding-related hospitalization or all-cause mortality were observed. Directionally similar results to those at 3 months were observed at 6 months for all outcomes. In conclusion, we observed fewer recurrent VTE cases and no increase in bleeding-related hospitalizations with rivaroxaban versus LMWH at 3 months in this patient cohort with various cancer types.

Rivaroxaban versus Apixaban for Treatment of Cancer-Associated Venous Thromboembolism in Patients at Lower Risk of Bleeding.

This retrospective study, utilizing U.S. electronic health record (EHR) data from January 2013 to December 2020, sought to assess whether rivaroxaban and apixaban had similar effectiveness and safety in the treatment of cancer-associated venous thromboembolism (VTE) in patients with a cancer type not associated with a high risk of bleeding. We included adults diagnosed with active cancer, excluding esophageal, gastric, unresected colorectal, bladder, noncerebral central nervous system cancers and leukemia, who experienced VTE and received a therapeutic VTE dose of rivaroxaban or apixaban on day 7 post-VTE, and were active in the EHR ≥12 months prior to the VTE. Primary outcome was the composite of recurrent VTE or any bleed resulting in hospitalization at 3 months. Secondary outcomes included recurrent VTE, any bleed resulting in hospitalization, any critical organ bleed, and composites of these outcomes at 3 and 6 months. Inverse probability of treatment-weighted Cox regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). We included 1,344 apixaban and 1,093 rivaroxaban patients. At 3 months, rivaroxaban was found to have similar hazard to apixaban for developing recurrent VTE or any bleed resulting in hospitalization (HR: 0.87; 95% CI: 0.60-1.27). No differences were observed between cohorts for this outcome at 6 months (HR: 1.00; 95% CI: 0.71-1.40) or for any other outcome at 3 or 6 months. In conclusion, patients receiving rivaroxaban or apixaban showed similar risks of the composite of recurrent VTE or any bleed resulting in hospitalization in patients with cancer-associated VTE. This study was registered at www.clinicaltrials.gov as #NCT05461807. Key Points Rivaroxaban and apixaban have similar effectiveness and safety for treatment of cancer-associated VTE through 6 months.Clinicians should therefore consider patient preference and adherence when choosing the optimal anticoagulant.

Effectiveness and Safety of Rivaroxaban and Low Molecular Weight Heparin in Cancer-Associated Venous Thromboembolism.

Background: Direct-acting oral anticoagulants (DOACs) are alternatives to low molecular weight heparin (LMWH) in most cancer-associated thrombosis (CAT) patients. Objectives: This study sought to compare the effectiveness and safety of rivaroxaban and LMWH for venous thromboembolism (VTE) treatment in patients with an active cancer type not associated with a high risk of DOAC bleeding. Methods: An analysis of electronic health records from January 2012 to December 2020 was performed. Patients were adults, had active cancer, experienced an index CAT event, and were treated with rivaroxaban or LMWH. Patients with cancers with an established high risk of bleeding on DOACs were excluded. Baseline covariates were balanced using propensity score-overlap weighting. HRs with 95% CIs were calculated. Results: We identified 3,708 CAT patients treated with rivaroxaban (29.5%) or LMWH (70.5%). The median (25th-75th percentiles) time on anticoagulation was 180 (69-365) and 96 (40-336) days for rivaroxaban and LMWH patients. At 3 months, rivaroxaban was associated with a 31% reduced risk of recurrent VTE vs LMWH (4.2% vs 6.1%; HR: 0.69; 95% CI: 0.51-0.92). No difference in bleeding-related hospitalizations or all-cause mortality was observed (HR: 0.79; 95% CI: 0.55-1.13 and HR: 1.07; 95% CI: 0.85-1.35, respectively). Rivaroxaban reduced the recurrent VTE risk (HR: 0.74; 95% CI: 0.57-0.97) but not bleeding-related hospitalizations or all-cause mortality at 6 months. At 12 months, no difference was observed between cohorts for any of the previously mentioned outcomes. Conclusions: Among active cancer patients experiencing VTE and not at high risk of bleeding on DOACs, rivaroxaban was associated with a reduced risk of recurrent VTE versus LMWHs at 3 and 6 months but not 12 months. (Observational Study in Cancer-Associated Thrombosis for Rivaroxaban-United States Cohort [OSCAR-US]; NCT04979780).

G-protein-coupled receptor dynamics: dimerization and activation models compared with experiment.

Our previously derived models of the active state of the ß2-adrenergic receptor are compared with recently published X-ray crystallographic structures of activated GPCRs (G-protein-coupled receptors). These molecular dynamics-based models using experimental data derived from biophysical experiments on activation were used to restrain the receptor to an active state that gave high enrichment for agonists in virtual screening. The ß2-adrenergic receptor active model and X-ray structures are in good agreement over both the transmembrane region and the orthosteric binding site, although in some regions the active model is more similar to the active rhodopsin X-ray structures. The general features of the microswitches were well reproduced, but with minor differences, partly because of the unexpected X-ray results for the rotamer toggle switch. In addition, most of the interacting residues between the receptor and the G-protein were identified. This analysis of the modelling has also given important additional insight into GPCR dimerization: re-analysis of results on photoaffinity analogues of rhodopsin provided additional evidence that TM4 (transmembrane helix 4) resides at the dimer interface and that ligands such as bivalent ligands may pass between the mobile helices. A comparison, and discussion, is also carried out between the use of implicit and explicit solvent for active-state modelling.