Systematic Review and Meta-Analysis of Real-World Studies Evaluating Rivaroxaban for Cancer-Associated Venous Thrombosis

Use of direct oral anticoagulants and low molecular weight heparin in venous thromboembolism associated with cancer: real-world evidence in Argentina

BACKGROUND

Venous thromboembolism (VTE) and major bleeding (MB) are common in cancer patients. Reduced-doses of antithrombotics as secondary prophylaxis have limited data. This work aims to describe and to compare treatments and outcomes for cancer-associated VTE.

RESEARCH DESIGN AND METHODS

Retrospective study. Adults with cancer-associated VTE were included. After 3-6 months of full-doses of anticoagulants, three strategies were considered: A) lowering the doses; B) maintaining full-doses; C) stopping treatment. The strategy and medication used were shown in a descriptive analysis and the rate of bleeding and VTE-recurrence between those in a comparative analysis.

RESULTS

A total of 420 patients were included, 56.2% received DOACs, 43.8% enoxaparin. Strategy was defined in 257 patients: A (50.2%), B (46.3%), and C (3.5%). Forty-one (9.8%) had VTE-recurrence and 15 (3.6%) had MB or clinically relevant non-major bleeding (CRNMB).According to strategy, recurrent-VTE was 8.5% (A), 4.2% (B), and 11.1 (C) (p = 0.22), MB or CRNMB was 0.8% (A), 1.7% (B), and 0% (C) (p = 0.64).

CONCLUSIONS

DOACs and strategy A were the most frequently used agent and strategy, respectively. There were no differences between medications or strategies used. The results must be interpreted with caution, and it is a retrospective single-center study, probably with information and selection bias.

Arguments for Using Direct Oral Anticoagulants in Cancer-Related Venous Thromboembolism

(1) Background: Patients with cancer with a hypercoagulable state present an increased incidence of venous thromboembolism (VTE). Neoplastic patients with concurrent VTE undergoing anticoagulant treatment face a series of issues. (2) The aim of the present paper is to systematically summarize current VTE management in patients with neoplasia and to review the current clinical evidence from meta-analyses of randomized controlled trials and guidelines regarding the administration of direct oral anticoagulants (DOACs) for cancer-associated VTE. (3) Search Strategy: We performed a review on meta-analyses of randomized controlled trials and guidelines in favor of the administration of DOACs in patients with cancer-associated VTE published in the last 6 years in the Medline (PubMed) and Embase databases. (4) Results: 21 meta-analyses, 14 randomized controlled studies comparing DOACs to VKAs and LMWH, and 7 national and international guidelines were identified. We identified five studies that show the antineoplastic effect of DOAC on experimental models. (5) Conclusions: DOACs can be seen as the first choice for VTE treatment in neoplastic patients who have a low risk of bleeding, who do not have severe renal impairment, and who are not undergoing treatments that could interact with DOAC's mechanism of action.

Rivaroxaban for cancer-associated venous thromboembolism

All cancers can increase the risk of developing venous thromboembolism (VTE), and anticoagulants should be considered as an optimal treatment for patients suffering from cancer-associated VTE. However, there is still a debate about whether the new oral anticoagulant, rivaroxaban, can bring better efficacy and safety outcomes globally. Thus, this systematic review and meta-analysis was conducted to evaluate the efficacy and safety of rivaroxaban. We searched PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and China National Knowledge Infrastructure for relevant published papers before 1 September 2019, with no language restrictions. The primary outcomes are defined as the recurrence of VTE. The secondary outcomes are defined as clinically relevant non-major bleeding, adverse major bleeding events, and all-cause of death. The data were analyzed by Stata with risk ratio (RR) and 95% confidence interval (CI). Four trials encompassing 1996 patients were included. Rivaroxaban reduced recurrent VTE with no significant difference (RR = 0.68, 95% CI = 0.43-1.07). Similarly, there were no significant differences in adverse major bleeding events (RR = 0.86, 95% CI = 0.37-2.00), clinically relevant non-major bleeding (RR = 1.24, 95% CI = 0.73-2.12) and all-cause mortality (RR = 0.76, 95% CI = 0.40-1.44). In a selected study population of cancer patients with VTE, rivaroxaban is as good as other anticoagulants. Further, carefully designed randomized controlled trials should be performed to confirm these results.

Comparative analysis of enoxaparin versus rivaroxaban in the treatment of cancer associated venous thromboembolism: experience from a tertiary care cancer centre

Background

Venous Thromboembolism (VTE) in cancer patients is associated with increased mortality and morbidity. While newer data on use of direct oral anticoagulants (DOACs) in treating cancer associated thrombosis (CAT) is promising; its data is still few and inconsistent across literature. We designed the study to assess if rivaroxaban would be an appealing alternate choice to treat CAT.

Methods

We conducted a retrospective study to evaluate the efficacy and safety profile of rivaroxaban versus enoxaparin in cancer patients after developing a symptomatic deep vein thrombosis (DVT) or pulmonary embolism (PE). Baseline patient characteristics and laboratory values were assessed in each arm. Primary efficacy outcome was measured by radiographically confirmed VTE recurrence at different intervals. Primary safety outcome was measured by presence of major and minor bleeding using the ISTH scale.

Results

Our study recruited 150 cancer patients with radiologically confirmed DVT and PE; 80 patients were evaluated in enoxaparin arm and 70 patients in rivaroxaban arm. Our results showed that there was no statistically significant difference between the incidence of VTE recurrence at 6 months between the enoxaparin and rivaroxaban arm (10% vs 14.2%, p = 0.42). Historically significant risk factors for VTE in cancer patients such as high platelet count, high leukocyte count, low hemoglobin level, high risk gastrointestinal, genitourinary and lung cancers were not found to be significantly associated with the risk of VTE recurrence. Primary safety outcome analysis also showed no statistically significant difference in major (11.2% vs 11.4%) and minor (15% vs 10%) bleeding between enoxaparin versus rivaroxaban arm respectively (p = 0.65).

Conclusion

We conclude that there was no significant difference seen between the efficacy and safety profile of enoxaparin and rivaroxaban in our cancer patient population.

Direct oral anticoagulants in patients with cancer

Purpose

This review summarizes the available evidence concerning direct oral anticoagulant (DOAC) use to treat venous thromboembolism (VTE) in patients with cancer as well as pertinent safety data on the use of DOACs in patients with both cancer and atrial fibrillation.

Summary

The introduction of DOACs into clinical practice changed the way thrombotic complications are managed and prevented in diverse patient populations, including VTE and atrial fibrillation. Low-molecular-weight heparins have been the standard of care for treating VTE in cancer patients due to superiority over vitamin K antagonists in preventing recurrent VTE. Therefore, widespread DOAC use for VTE in patients with active cancer has not been adopted.

Conclusion

Recent randomized clinical trials (SELECT-D, Hokusai VTE Cancer) have provided evidence that DOACs may have a role in treating VTE in cancer patients.

Rivaroxaban for prevention and treatment of venous thromboembolism

Until recently, heparins and vitamin K antagonists (VKAs) were the cornerstones for prevention and treatment of venous thromboembolism (VTE). This situation changed with the introduction of the direct oral anticoagulants, which are now replacing low-molecular-weight heparin for thromboprophylaxis after elective hip or knee arthroplasty and VKAs for VTE treatment. Rivaroxaban, an oral factor Xa inhibitor, was the first direct oral anticoagulant licensed for VTE prevention and treatment. This paper provides the rationale for factor Xa as a target for anticoagulants, describes the development of rivaroxaban, reviews its pharmacological profile, discusses the clinical trials with rivaroxaban for VTE prevention and treatment and highlights areas of uncertainty.