Subgroup Analysis of Patients with Cancer in XALIA: A Noninterventional Study of Rivaroxaban versus Standard Anticoagulation for VTE

Safety and Efficacy of Direct Oral Anticoagulants for Treatment of Venous Thromboembolism in Pediatric Oncology Patients

BACKGROUND/OBJECTIVES

Children with cancer have an increased risk for developing a venous thromboembolism (VTE) during their treatment course. Direct oral anticoagulants (DOACs) represent a relatively new class of oral medications to treat VTE; however, data are limited to support use in this patient group. Given the safety and efficacy data from numerous perspective adult studies, providers now consider off-label use in select children.

METHODS

We performed a single-center, retrospective review of children 0 to 20 years of age from 2012 to 2020 with malignancy and confirmed VTE, with the objective to evaluate the hypothesis that the safety and the efficacy of DOACs are noninferior to enoxaparin in this population. The primary composite efficacy outcome comprises symptomatic recurrent VTE, death due to VTE, and thrombus progression. The principal safety outcome is a combination of major and clinically relevant nonmajor bleeding.

RESULTS

The safety and efficacy outcomes collected revealed that DOAC use was equivalent when compared with the enoxaparin group for treatment of VTE. One patient in the DOAC group had clinically relevant, nonmajor bleeding compared with 2 patients in the enoxaparin group. No treatment failures were observed.

CONCLUSIONS

This single-center study suggests that DOACs are both safe and efficacious for the treatment of VTE in children with cancer. It also highlights the need for larger studies to address this clinical question.

Cancer-Associated ThrOmboSIs - Patient-Reported OutcoMes With RivarOxaban (COSIMO) - Baseline characteristics and clinical outcomes

BACKGROUND

Patients with cancer-associated thrombosis (CAT) have a high risk of recurrent venous thromboembolic events, which contribute to significant morbidity and mortality. Direct oral anticoagulants may provide a convenient treatment option for these patients.

OBJECTIVES

To assess clinical characteristics and outcomes of patients with active cancer changing to rivaroxaban after ≥4 weeks of standard therapy for the treatment of venous thromboembolism (VTE) in clinical practice. This analysis focused on secondary outcomes of Cancer-associated thrOmboSIs - Patient-reported outcoMes with rivarOxaban (COSIMO).

PATIENTS

COSIMO was a multinational, prospective, noninterventional, single-arm cohort study. Overall, 505 patients received at least one dose of rivaroxaban; 96.6% changing from low-molecular-weight heparin, 1.6% from a vitamin K antagonist, and 1.8% from fondaparinux.

RESULTS

Most patients had solid tumors (n = 449; 88.9%) and approximately half of these patients had metastases. The qualifying venous thromboembolic event was deep vein thrombosis (DVT) in 45.3% of patients, pulmonary embolism (PE) in 37.2% of patients, DVT with PE in 9.7% of patients, and catheter-associated DVT in 7.5% of patients. Approximately 75.1% of patients received rivaroxaban for at least 3 months; 150 (29.7%) patients received concomitant chemotherapy during the study. VTE recurrence, major bleeding, nonmajor bleeding, and major adverse cardiovascular events occurred in 18 (3.6%), 18 (3.6%), 81 (16.0%), and 12 (2.4%) patients, respectively.

CONCLUSIONS

In patients with CAT who changed to rivaroxaban treatment after ≥4 weeks of standard therapy, the observed incidence proportions of recurrent VTE and bleeding events were in keeping with the recognized effectiveness and safety profile of rivaroxaban for the treatment of CAT.

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.

The Role of Direct Oral Anticoagulants in Cancer-Associated Thrombosis According to the Current Literature

Venous thromboembolism (VTE) is a common complication among patients suffering from malignancies, leading to an increased mortality rate. Novel randomized trials have added valuable information regarding cancer-associated thrombosis (CAT) management using direct oral anticoagulants (DOACs). The aim of this study is to present an overview of the current literature and recommendations in CAT treatment. A few randomized control trials (RCTs) have been integrated suggesting that DOACs may be effectively applied in CAT patients compared to low molecular weight heparins (LMWHs) with a decreased mortality and VTE recurrence rate. However, the risk of bleeding is higher, especially in patients with gastrointestinal malignancies. Real-world data are in accordance with these RCT findings, while in the currently available recommendations, DOACs are suggested as a reliable alternative to LMWH during the initial, long-term, and extended phase of treatment. Data retrieved from the current literature, including RCTs and “real-world” studies, aim to clarify the role of DOACs in CAT management, by highlighting their benefits and remarking upon the potential adverse outcomes. Current recommendations suggest the use of DOACs in well-selected patients with an increasing level of evidence through years.

Effectiveness and safety of direct oral anticoagulants in patients with cancer associated venous thromboembolism

INTRODUCTION

Real-world evidence on the effects of direct oral anticoagulants (DOACs) in patients with cancer associated venous thromboembolism (VTE) is limited. Thus, our population-based cohort study aimed to assess the effectiveness and safety of DOACs compared to the standard of care low-molecular-weight heparin (LMWH) in this vulnerable population.

MATERIALS AND METHODS

Using linked administrative healthcare databases from the province of Québec, Canada, we identified patients with incident VTE from 2012 to 2015 and a cancer diagnosis in the year before the VTE, who initiated treatment with anticoagulants within 30 days after the VTE. Using an active comparator new-user design with an as-treated exposure definition, we compared use of DOACs with use of LMWH. Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of recurrent VTE, major bleeding, and all-cause mortality. In secondary analyses, we stratified by age and sex.

RESULTS

Overall, 4438 patients with cancer associated VTE initiated treatment with anticoagulants (513 DOACs, 2698 LMWH). During a median follow-up of 0.3 years, and compared with LMWH, DOACs were associated with a decreased risk of recurrent VTE (HR, 0.54; 95% CI, 0.36-0.82) and major bleeding (HR, 0.54; 95% CI, 0.31-0.96). We also observed a decreased risk of all-cause mortality with DOACs compared with LMWH (HR, 0.14; 95% CI, 0.09-0.22). Age and sex did not modify the associations.

CONCLUSIONS

DOACs were associated with improved effectiveness and safety compared with LMWH in patients with cancer related VTE. Unmeasured confounding probably contributed to our findings on all-cause mortality.

The Net Clinical Benefit of Rivaroxaban Compared to Low-Molecular-Weight Heparin in the Treatment of Cancer-Associated Thrombosis: Systematic Review and Meta-Analysis

Cancer-associated thrombosis (CAT) carries significant morbidity and mortality. Low-molecular-weight heparin (LMWH) remains the standard of care, with recent systematic studies suggesting the efficacy and safety of rivaroxaban in the treatment of CAT. Uncertainty, however, remains regarding rivaroxaban efficacy and safety in real-world settings. We performed a systematic review and meta-analysis of studies comparing rivaroxaban to LMWH. We searched PubMed, MEDLINE, and EMBASE. The primary outcome was the net clinical benefit (NCB), while rates of major bleeding (MB), venous thromboembolism (VTE), clinically relevant nonmajor bleeding (CRNMB), and all-cause mortality events were secondary outcomes. Seventeen studies were included in the final analysis. Rivaroxaban had a better NCB (relative risk [RR] = 0.82; 95% CI = 0.75-0.89, Q = 10.51, I ² = 0%), less VTE events (RR = 0.73, 95% CI = 0.65-0.82, Q = 6.76, I ² = 0%), and lower all-cause mortality (RR = 0.72, 95% CI = 0.57-0.91, Q = 32.8, I ² = 79%) compared to LMWH. Additionally, comparable MB events (RR = 1.07, 95% CI = 0.85-1.33, Q = 16.9, I ² = 11%). However, CRNMB events were higher in the rivaroxaban group (RR = 2.02, 95% CI = 1.46-2.80, Q = 9.9, I ² = 19%). Additional analyses demonstrated consistency of results. Our review encompassing data from randomized and real-world data suggested rivaroxaban superiority compared to LMWH in terms of a better NCB, fewer VTE events, lower all-cause mortality, and comparable MB risk while carrying a higher risk of CRNMB. These findings support the use of rivaroxaban in the treatment of CAT. Additionally, it warrants a sizable randomized controlled study testing the superiority of rivaroxaban versus LMWH formulation and ascertaining bleeding outcomes according to cancer type and site.

Treatment of cancer-associated thrombosis: The evolution of anticoagulant choice and clinical insights into practical management

Low-molecular-weight heparin (LMWH) therapy is recommended over vitamin K antagonists (VKAs) for the treatment of cancer-associated thrombosis (CAT) and extended therapy is recommended in those with active cancer to prevent recurrent thrombosis. However, the inconvenience of daily subcutaneous injections and the cost of LMWH therapy hinder long-term use. Observational data demonstrate that persistence with LMWH therapy is low in clinical practice and that many patients are switched to oral alternatives - namely VKAs and direct oral anticoagulants (DOACs). Recently, the efficacy and safety of apixaban, edoxaban, and rivaroxaban versus LMWH therapy for the treatment of CAT have been demonstrated in randomized trials. This review provides a critical evaluation of studies with DOACs in this setting and an update on the guidance regarding anticoagulant use for the treatment of CAT. In recognition of the heterogeneity of patients with cancer and the challenges of CAT, patient cases with expert clinical perspectives are presented.

Effectiveness and safety of rivaroxaban compared with low-molecular-weight heparin in cancer-associated thromboembolism

Guidelines provide differing recommendations regarding direct-acting oral anticoagulants vs low-molecular-weight heparin (LMWH) for treatment of cancer-associated thrombosis (CAT). This study was undertaken to evaluate the effectiveness and safety of rivaroxaban vs LMWH for treatment of CAT. Using US Surveillance, Epidemiology and End Results-Medicare-linked data from 2013 through 2016, we evaluated adults with active breast, lung, ovarian, or pancreatic cancer, who were admitted to the hospital or treated in the emergency department for CAT and were prescribed rivaroxaban or LMWH for outpatient anticoagulation. Patients with luminal gastrointestinal or genitourinary cancers were excluded. Rivaroxaban and LMWH users were 1:1 propensity score matched. Outcomes included the composite of recurrent thrombosis or major bleeding, each outcome separately, and mortality at 6 months, using an intent-to-treat approach. On-treatment analysis after 12 months was also performed. Proportional hazards models for the subdistribution of competing risk were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). We included 529 rivaroxaban- and 529 LMWH-treated patients with CAT. Rivaroxaban was not associated with differences in risk of the composite outcome (HR, 0.71; 95% CI, 0.41-1.22), major bleeding (HR, 1.01; 95% CI, 0.50-2.01), or mortality (HR, 0.87; 95% CI, 0.70-1.07) vs LMWH, but it reduced recurrent thrombosis (HR, 0.37; 95% CI, 0.15-0.95). On-treatment analysis at 12 months showed similar results. Rivaroxaban may be a reasonable alternative to LMWH for patients with CAT without gastrointestinal or genitourinary cancer.

Cancer-associated venous thromboembolism: Treatment and prevention with rivaroxaban

Cancer-associated venous thromboembolism (VTE) is a frequent, potentially life-threatening event that complicates cancer management. Anticoagulants are the cornerstone of therapy for the treatment and prevention of cancer-associated thrombosis (CAT); factor Xa-inhibiting direct oral anticoagulants (DOACs; apixaban, edoxaban, and rivaroxaban), which have long been recommended for the treatment of VTE in patients without cancer, have been investigated in this setting. The first randomized comparisons of DOACs against low-molecular-weight heparin for the treatment of CAT indicated that DOACs are efficacious in this setting, with findings reflected in recent updates to published guidance on CAT treatment. However, the higher risk of bleeding events (particularly in the gastrointestinal tract) with DOACs highlights the need for appropriate patient selection. Further insights will be gained from additional studies that are ongoing or awaiting publication. The efficacy and safety of DOAC thromboprophylaxis in ambulatory patients with cancer at a high risk of VTE have also been assessed in placebo-controlled randomized controlled trials of apixaban and rivaroxaban. Both studies showed efficacy benefits with DOACs, but both studies also showed a nonsignificant increase in major bleeding events while on treatment. This review summarizes the evidence base for rivaroxaban use in CAT, the patient profile potentially most suited to DOAC use, and ongoing controversies under investigation. We also describe ongoing studies from the CALLISTO (Cancer Associated thrombosis-expLoring soLutions for patients through Treatment and Prevention with RivarOxaban) program, which comprises several randomized clinical trials and real-world evidence studies, including investigator-initiated research.

Rivaroxaban and the EINSTEIN clinical trial programme

: Rivaroxaban, a direct oral anticoagulant, is widely used for the treatment of venous thromboembolism (VTE) in adult patients. The approval of rivaroxaban for the treatment of deep vein thrombosis and pulmonary embolism and the extended secondary prevention of recurrent VTE is based on the results of the EINSTEIN DVT and EINSTEIN PE trials, and the EINSTEIN EXT and EINSTEIN CHOICE trials, respectively. This review provides an updated overview of these completed EINSTEIN studies in adult patients, including results of subanalyses in patients at high risk of recurrent VTE, and discusses the emerging data from the EINSTEIN Junior programme, which is evaluating the use of rivaroxaban for the treatment of paediatric VTE. In the EINSTEIN DVT and EINSTEIN PE trials, rivaroxaban (15 mg twice daily for 21 days, followed by 20 mg once daily thereafter) was shown to be an effective and safe alternative to standard anticoagulation for the treatment of deep vein thrombosis and pulmonary embolism in a broad range of adult patients. These results are supported by increasing amounts of real-world data from patients treated with rivaroxaban in routine clinical practice worldwide. In the EINSTEIN EXT and EINSTEIN CHOICE trials, rivaroxaban was superior to placebo and acetylsalicylic acid, respectively, for the extended treatment of VTE - physicians can now choose between two doses of rivaroxaban (20 mg once daily or 10 mg once daily) for the extended prevention of recurrent VTE, based on a patient's risk of recurrence, bleeding and personal preferences.

Predictive value of venous thromboembolism (VTE)-BLEED to predict major bleeding and other adverse events in a practice-based cohort of patients with VTE: results of the XALIA study

Venous thromboembolism (VTE)-BLEED, a decision tool for predicting major bleeding during chronic anticoagulation for VTE has not yet been validated in practice-based conditions. We calculated the prognostic indices of VTE-BLEED for major bleeding after day 30 and day 90, as well as for recurrent VTE and all-cause mortality, in 4457 patients enrolled in the international, prospective XALIA study. The median at-risk time was 190 days (interquartile range 106-360). The crude hazard ratio (HR) for major bleeding after day 30 was 2·6 [95% confidence interval (CI) 1·3-5·2] and the treatment-adjusted HR was 2·3 (95% CI 1·1-4·5) for VTE-BLEED high (versus low) risk patients: the corresponding values for major bleeding after day 90 were 3·8 (95% CI 1·6-9·3) and 3·2 (95% CI 1·3-7·7), respectively. The predictive value of VTE-BLEED was similar in selected patients with unprovoked VTE or those treated with rivaroxaban. High VTE-BLEED score was associated with higher incidence of all-cause mortality (treatment-adjusted HR 11, 95% CI 4·8-23), but not evidently with recurrent VTE (treatment-adjusted HR 1·5; 95% CI 0·85-2·7). These results confirm the predictive value of VTE-BLEED in practice-based data in patients treated with rivaroxaban or conventional anticoagulation, supporting the hypothesis that VTE-BLEED may be useful for making management decisions on the duration of anticoagulant therapy.

Direct oral anticoagulants for the treatment of venous thromboembolism in cancer patients: Potential for drug-drug interactions

Patients with cancer are at high risk of developing venous thromboembolism (VTE). Although the recommended low molecular weight heparins (LMWHs) are more effective than vitamin K antagonists in treating VTE in patients with cancer, they have limitations and contraindications. Direct oral anticoagulants (DOACs) circumvent some of these limitations. Here, DOAC use for VTE treatment in patients receiving anticancer therapy is reviewed, focusing on metabolic and elimination pathways, potential drug-drug interactions and practical considerations. DOACs are typically substrates of the cytochrome P450-based metabolic pathways and/or ATP-binding cassette transporters. Although many cancer therapies influence these pathways, only a minority of these drugs interact with DOACs. Phase III DOAC trials provided encouraging safety and efficacy data for their use in cancer-associated thrombosis. Furthermore, numerous ongoing DOAC trials strive to gain a better understanding of the treatment of cancer-associated thrombosis and continue to support a role for DOACs in this setting.

COSIMO - patients with active cancer changing to rivaroxaban for the treatment and prevention of recurrent venous thromboembolism: a non-interventional study

BACKGROUND

Around 20% of venous thromboembolism (VTE) cases occur in patients with cancer. Current guidelines recommend low molecular weight heparin (LMWH) as the preferred anticoagulant for VTE treatment. However, some guidelines state that vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) are acceptable alternatives for long-term therapy in some patients if LMWHs are not available. LMWHs and VKAs have a number of drawbacks that can increase the burden on patients. DOACs, such as rivaroxaban, can ameliorate some burdens and may offer an opportunity to increase patient satisfaction and health-related quality of life (HRQoL). The Cancer-associated thrOmboSIs - patient-reported outcoMes with rivarOxaban (COSIMO) study is designed to provide real-world information on treatment satisfaction in patients with active cancer who switch from LMWH or VKA to rivaroxaban for the treatment of acute VTE or to prevent recurrent VTE.

METHODS

COSIMO is a prospective, non-interventional, single-arm cohort study that aims to recruit 500 patients in Europe, Canada and Australia. Adults with active cancer who are switching to rivaroxaban having received LMWH/VKA for the treatment and secondary prevention of recurrent VTE for at least the previous 4 weeks are eligible. Patients will be followed for 6 months. The primary outcome is treatment satisfaction assessed as change in the Anti-Clot Treatment Scale (ACTS) Burdens score at week 4 after enrolment compared with baseline. Secondary outcomes include treatment preferences, measured using a discrete choice experiment, change in ACTS Burdens score at months 3 and 6, and change in HRQoL (assessed using the Functional Assessment of Chronic Illness Therapy - Fatigue questionnaire). COSIMO will collect data on patients' medical history, patterns of anticoagulant use and incidence of bleeding and thromboembolic events. Study recruitment started in autumn 2016.

CONCLUSIONS

COSIMO will provide information on outcomes associated with switching from LMWH or VKA therapy to rivaroxaban for the treatment or secondary prevention of cancer-associated thrombosis in a real-life setting. The key goal is to assess whether there is a change in patient-reported treatment satisfaction. In addition, COSIMO will facilitate the evaluation of the safety and effectiveness of rivaroxaban in preventing recurrent VTE in this patient population.

TRIAL REGISTRATION

NCT02742623. Registered 19 April 2016.

[Treatment of cancer associated thrombosis: Which role for direct oral anticoagulants in 2018?]

Low molecular weight heparin (LMWH) for at least 3-6 months is the current standard of care for the treatment of cancer associated venous thromboembolism (VTE). Anticoagulation should be continued as long as the cancer is active. In recent years, several direct-acting oral anticoagulants (DOACs) have been approved for the treatment of VTE in the general population. These drugs have progressively emerged as attractive alternatives with the potential to overcome the limitations of LMWH. Due to the lack of high quality prospective data, DOACs are currently not recommended for the treatment of cancer associated VTE yet. Indeed, evidence supporting the use of DOACs in this specific population remains limited, and concerns have been raised about their safety and efficacy in this setting. However, a pattern of increased use of DOACs has been observed in the cancer population. Meta-analyses of Phase III trials of DOACs in VTE as well as analysis of large health care claims databases and non-controlled retrospective studies suggest that DOACs might have similar effectiveness and safety to LMWH for the management of cancer associated VTE. Results from 2 randomized clinical trial (RCT), HOKUSAI-Cancer and SELECT-D, were recently released. Based on a meta-analysis of these 2 RCTs, compared to LMWH, DOACs had lower 6 month recurrent VTE but higher major bleeding. Thus, DOACs should be used with caution in cancer patients and a careful evaluation of the risks and benefits for individual patients is warranted. Ongoing studies will provide much needed evidence to guide clinical care.

Antithrombotic therapy for venous thromboembolism in patients with cancer: expert guidance

INTRODUCTION

Most of the current clinical guidelines recommend the use of Low-Molecular-Weight Heparins (LMWHs) for cancer-associated thrombosis (CAT). The Hokusai VTE-cancer trial reported the first results of a direct comparison between a direct oral anticoagulant (DOAC), edoxaban, and LMWH in this setting.

AREAS COVERED

This review aims to critically appraise the currently available evidence on the efficacy and safety of anticoagulant agents for the long-term treatment of CAT and to provide an expert opinion and guidance in this field.

EXPERT OPINION

Based on the available evidence, DOACs represent a valid alternative to LMWH for the treatment of CAT for the majority of patients with active cancer. Currently, most solid evidence comes from the Hokusai VTE-cancer study, which showed that edoxaban is non-inferior to the LMWH dalteparin, with a trend toward fewer recurrent venous thromboembolic events, but with more major bleeding events. Similar findings were reported with rivaroxaban, although the study was not sufficiently powered to allow definitive conclusions. The majority of bleeding events occurred in the upper gastrointestinal tract and in patients with gastrointestinal cancer. Thus, LMWH remains the preferred option for patients with gastrointestinal cancer. Additional studies aimed to confirm these findings with other DOACs are now warranted.

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

INTRODUCTION

While not designated as guideline-recommended first-line anticoagulation therapy, about one in five patients in the United States receive rivaroxaban for the treatment of cancer-associated venous thrombosis (CAT).

METHODS

A systematic review and meta-analysis were performed to evaluate the incidences of recurrent venous thromboembolism (VTE), major bleeding, and all-cause mortality in rivaroxaban patients treated for CAT in routine practice. Literature searches of MEDLINE and SCOPUS were performed through September 2017 to identify real-world studies of ≥ 20 patients evaluating the incidence of recurrent VTE, major bleeding, or all-cause mortality in CAT patients anticoagulated with rivaroxaban. Using a Hartung-Knapp random-effects model, the pooled incidence estimates and 95% confidence intervals (CIs) were calculated for each end point.

RESULTS

Six studies evaluating rivaroxaban for CAT were identified. Of these, three were prospective and three were retrospective. Study sample sizes ranged from 41 to 949 patients, and duration of follow-up ranged from 164 to 496 days. The most frequent active cancer sites reported in studies were gastrointestinal (range: 12.0-56.0%), genitourinary (range: 8.6-26.0%), and breast (range: 9.3-25.5%). The weighted average incidences of recurrent VTE, major bleeding, and all-cause mortality were 4.2% (95% CI = 2.6-6.6%; I² = 31%), 2.9% (95% CI = 1.6-5.0%; I² = 59%), and 16.1% (95% CI = 6.0-36.6%; I² = 96%).

CONCLUSIONS

This meta-analysis suggests that incidences of recurrent VTE and major bleeding among rivaroxaban-managed patients are not dissimilar to those seen in recent randomized trials of anticoagulation in CAT. The pooled incidence for mortality was lower than reported in many anticoagulation CAT trials. This may suggest that rivaroxaban is being used in CAT patients who have less severe cancer.