Comparison between direct factor Xa inhibitors and low-molecular-weight heparin for efficacy and safety in the treatment of cancer-associated venous thromboembolism: A meta-analysis

Apixaban versus low molecular weight heparin in patients with cancer-associated venous thromboembolism: a systematic review and meta-analysis

Background

The optimal treatment regimen for patients with cancer-associated venous thromboembolism (CA-VTE) remains unclear. Therefore, the authors sought to compare the outcomes of (VKAs) versus direct apixaban and low molecular weight heparin (LMWH) in patients with CA-VTE.

Methods

MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials (RCTs) and observational studies comparing the efficacy and safety of apixaban and LMWH in patients with CA-VTE. Major bleeding, clinically relevant non-major bleeding (CRNMB), recurrence of pulmonary embolism (PE), deep venous thrombosis (DVT) and bleeding-related mortality were among outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95% CIs.

Results

The analysis included 12 011 patients from 3 RCTs and 2 observational studies. Compared to LMWH, apixaban significantly decreased the risk of major bleeding [RR 0.67 (95% CI 0.54, 0.83); P=0.0003, I2=0%] without significantly changing the risk of clinically relevant non-major bleeding [RR 0.96 (95% CI 0.64, 0.1.45); P=0.85, I2=57%]. Patients on apixaban had a noticeably reduced the risk of recurrence of PE than those taking LMWH, according to a meta-analysis [RR 0.56 (95% CI 0.32, 0.99); P=0.05, I2=0%]. There was no discernible difference between apixaban and LMWH in bleeding-related mortality events [RR 0.20 (95% CI 0.01, 4.18); P=0.30, I2=NA%], and recurrence of DVT [RR 0.60 (95% CI 0.22, 1.59); P=0.23, I2=32%].

Conclusion

Due to its lower risk of severe bleeding and reduced PE recurrence, apixaban may be a preferable treatment option for CA-VTE, but additional research is required to validate these conclusions and evaluate its long-term efficacy and safety.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review.  OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence).   For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence).  AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.

Factor Xa inhibitor for venous thromboembolism management in patient with cancer: a systematic review and meta-analysis

Background: An earlier systematic review reported no differences in the incidence of recurrent venous thromboembolism and major bleeding between factor Xa inhibitors and standard anticoagulation. The present meta-analysis aimed to assess the effectiveness of factor Xa inhibitors for the management of venous thromboembolism (VTE), specifically in patients with cancer, as there were more randomized clinical trials (RCTs) available. Methods: The PubMed and Cochrane Library databases were systematically screened for all RCTs assessing factor Xa inhibitor efficacy for VTE management in cancer patients. Using RevMan 5.3, we performed a Mantel-Haenszel fixed-effects meta-analysis of the following outcomes: recurrent VTE, VTE events, and major bleeding rates. Results: We identified 11 studies involving 7,965 patients. Factor Xa inhibitors were superior in preventing VTE recurrence, compared to low-molecular-weight heparin (LMWH) (OR 0.60; 95% CI 0.45-0.80; P < 0.01) and vitamin K antagonists (VKA) (OR 0.51; 95% CI 0.33-0.78; P < 0.01). As prophylaxis, factor Xa inhibitors had a similar rate of VTE compared to VKAs (OR 1.08 [95% CI 0.31-3.77]; P = 0.90) and a lower rate compared to placebo (OR 0.54 [95% CI 0.35-0.81]; P < 0.01). Major bleeding rates were higher with factor Xa inhibitors than with LMWHs (OR 1.34 [95% CI 0.83-2.18]; P = 0.23), but significantly lower than VKAs (OR 0.71 [95% CI 0.55-0.92]; P < 0.01). Conclusions: Factor Xa inhibitors are effective for VTE management in patients with cancer; however, they are also associated with an increased bleeding risk compared to LMWH, but decreased when compared to VKA.

Direct oral anticoagulant versus low-molecular-weight heparin for treatment of venous thromboembolism in cancer patients: An updated meta-analysis of randomized controlled trials

BACKGROUND

Cancer associated venous thromboembolism (VTE) results in significant morbidity and mortality. Low molecular weight heparin (LMWH) has been standard of care for treatment of cancer-associated VTE, however direct oral anticoagulants (DOACs) are emerging as alternative treatment options.

OBJECTIVE

To compare the benefits and harms of DOACs versus LMWH for treatment of VTE in cancer.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception to April 2020.

STUDY SELECTION

Randomized controlled trials (RCT) comparing DOACs with LMWH for treatment of VTE in cancer patients.

DATA SYNTHESIS

Four good-quality RCTs, met inclusion criteria. Compared with LMWH, DOACs were associated with lower rates of VTE recurrence (RR 0.62; 95% CI: 0.44-0.87; P = 0.006), and DVT recurrence (RR 0.61; 95% CI: 0.4-0.94; P = 0.02) but not PE recurrence (RR 0.73; 95% CI: 0.51-1.04; P = 0.08), in cancer patients. However, the risk of clinically relevant non-major bleeding (CRNMB) (RR 1.58; 95% CI: 1.11-2.24; P = 0.01), and major bleeding in gastrointestinal cancer (RR 2.55; 95% CI 1.24-5.27, P = 0.01), were higher with DOACs. The risk of overall major bleeding (RR 1.33; 95% CI: 0.84-2.1; P = 0.22), all-cause mortality (RR 0.99; 95% CI: 0.84-1.17; P = 0.92), VTE-related mortality (RR: 1; 95% CI: 0.29-3.44; P = 1) and bleeding-related mortality (RR: 0.71; 95% CI: 0.17-2.91; P = 0.63), were similar in both treatment groups.

CONCLUSION

Among cancer patients with VTE, treatment with DOACs is associated with a significant reduction of VTE and DVT recurrence, compared to LMWH. These benefits were offset by an increased risk of CRNMB, and major bleeding in gastrointestinal cancer.