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

Structure and pharmacokinetics/pharmacodynamics of the anticoagulant tetradecasaccharide oHG-14 as an intrinsic tenase inhibitor

The intrinsic tenase complex (iXase) is an attractive antithrombotic target to treat or prevent pathological thrombosis with negligible bleeding risk. Fucosylated glycosaminoglycan (FG) is a promising anticoagulant by inhibiting iXase. A depolymerized FG (dHG-5) as an anticoagulant has been approved for clinical trials. Given that dHG-5 is a multi-component drug candidate consisting of a homologous series of oligosaccharides, it is difficult to predict a clear pharmacokinetics. Here, as a major oligosaccharide component, the tetradecasaccharide (oHG-14) was purified from dHG-5 and its structure was defined as L-Fuc3S4S-α(1,3)-L-Δ4,5GlcA-α(1,3)-{D-GalNAc4S6S-β(1,4)-[L-Fuc3S4S-α(1,]3)-D-GlcA-β(1,3)-}3-D-GalNAc4S6S-β(1,4)-[L-Fuc3S4S-α(1,]3)-D-GlcA-ol. oHG-14 showed potent iXase inhibitory activity in vitro and antithrombotic effect in vivo comparable to dHG-5. After single subcutaneous administration of oHG-14 at 8, 14.4 and 32.4 mg/kg to rats, the absolute bioavailability was 71.6 %-80.9 % determined by the validated bioanalytical methods. The maximum concentration (Cmax) was 3.73, 8.07, and 11.95 μg/mL, respectively, and the time reaching Cmax (Tmax) was about 1 h. oHG-14 was mainly excreted by kidney as the parent compound with the elimination kinetics of first-order linear model. Anticoagulant activity of oHG-14 was positively correlated with its concentration in rat plasma. The pharmacokinetics/pharmacodynamics (PK/PD) of oHG-14 is similar to that of dHG-5. This study could provide supportive data for the clinical trial of dHG-5 and further development of pure oligosaccharide as an antithrombotic drug candidate.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and active cancer who also had prior bleed or prior renal disease

OBJECTIVE

Patients with active cancer and venous thromboembolism (VTE) have elevated risk of recurrent VTE (rVTE) and major bleeding (MB). The risk is even higher within those with a prior bleeding event or renal disease. There is a need to understand the risk of rVTE and MB of commonly used anticoagulants among these high-risk patients.

METHODS

VTE patients with active cancer and treated with apixaban, warfarin, or low molecular weight heparin (LMWH) within 30 days of VTE were identified from five claims databases in the United States. Inverse probability of treatment weighting (IPTW) was used to balance patient characteristics. The post-IPTW population was stratified by prior bleed or renal disease status. Cox proportional hazards models were used to evaluate interactions between treatment and prior bleed or renal disease on risk of rVTE and MB, with p value <.1 considered significant.

RESULTS

Study criteria were met by 30,586 VTE cancer patients: 35.0% had prior bleed and 29.0% had renal disease. For apixaban, LMWH, and warfarin cohorts, the incidence (events per 100 person-years) of MB was higher in patients with prior bleed (17.48 vs 7.58, 25.61 vs 13.11, and 20.38 vs 8.97) or renal disease (15.79 vs 8.71, 22.11 vs 15.90, and 18.49 vs 10.39) vs those without the conditions. Generally, there were no significant interactions between anticoagulant use and prior bleed or renal disease on rVTE and MB (p for interaction >.1).

CONCLUSION

The incidence of MB was higher among those with prior bleed or renal disease. Effects of apixaban, warfarin, or LMWH were generally consistent regardless of prior bleed or renal disease status.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and common cancers or cancers with high venous thromboembolism risk

Aim: Treatment effects among anticoagulant-treated patients with venous thromboembolism (VTE) and cancer across tumor types were evaluated. Methods: Patients initiating an anticoagulant within 30 days after VTE were identified. After inverse probability treatment weighting, patients were stratified by tumor type. Interactions between treatment and tumor type on recurrent VTE, major bleeding and clinically relevant non-major bleeding were assessed using Cox proportional hazard models. Results: Treatment effects were generally not significantly different among patients with or without the following cancer types: prostate, breast, lung, pancreatic or multiple myeloma. Few significant interactions were observed for lung and pancreatic cancer. Conclusion: Anticoagulant treatment effects were generally consistent across tumor types. The significant interactions may indicate tumor-specific effects of anticoagulants, but further research is needed.

Trends in Anticoagulant Utilization and Clinical Outcomes for Cancer-Associated Thrombosis: A Multicenter Cohort Study in Thailand's Upper-Middle-Income Country Setting

PURPOSE

To evaluate anticoagulant trends and clinical outcomes in the management of cancer-associated thrombosis (CAT) within Thailand, an upper-middle-income country (UMIC).

METHODS

This multicenter retrospective cohort study included adult patients with cancer diagnosed with venous thromboembolism (VTE) hospitalized in Thailand from 2017 to 2021. Anticoagulants were classified as low-molecular-weight heparin (LMWH), direct oral anticoagulants (DOACs), and warfarin. Prescription trends were assessed, and patients were followed for 1 year, or until 2022 to evaluate outcomes. The primary effectiveness outcome was recurrent VTE, whereas the primary safety outcome was major bleeding. Secondary outcomes included net clinical benefit and all-cause mortality. Treatment effects were examined using inverse probability of treatment weighting (IPTW) Cox proportional hazards models.

RESULTS

Among 1,611 patients (61.3% female; mean age, 58.8 years; standard deviation, 13.1 years), 86% received LMWH, 10% warfarin, and 4% DOACs. In the study cohort, LMWH prescriptions remained consistent, warfarin use declined, and DOAC prescriptions notably increased. In IPTW analysis, DOACs showed comparable rates of VTE recurrence (weighted hazard ratio [HR], 0.77 [95% CI, 0.22 to 2.70]; P = .679) and major bleeding (weighted HR, 0.62 [95% CI, 0.15 to 2.55]; P = .506) with LMWH. Warfarin had a higher risk of major bleeding (weighted HR, 2.74 [95% CI, 1.12 to 6.72]; P = .028) but a similar rate of VTE recurrence (weighted HR, 1.46 [95% CI, 0.75 to 2.84]; P = .271) compared with LMWH. Secondary outcomes were consistent across groups.

CONCLUSION

LMWH remains the primary treatment for CAT, in line with current guidelines. The study highlights the challenges faced in these settings with the continuous use of warfarin. The comparable efficacy and safety of DOACs with LMWH suggest a potential shift in CAT management within UMICs.

Effectiveness and safety of anticoagulants among venous thromboembolism cancer patients with and without brain cancer

INTRODUCTION

Patients with brain cancer are at a high risk of developing venous thromboembolism (VTE) and are underrepresented in clinical trials. This study compared the risk of recurrent VTE (rVTE), major bleeding (MB), and clinically relevant non-major bleeding (CRNMB) among VTE cancer patients initiating apixaban, low molecular weight heparin (LMWH), or warfarin stratified by patients with brain vs other cancer types.

MATERIALS AND METHODS

Active cancer patients initiating apixaban, LMWH, or warfarin within 30 days after VTE diagnosis were identified from 4 US commercial and the Medicare databases. Inverse probability of treatment weights (IPTW) was used to balance patient characteristics. Cox proportional hazards models were used to evaluate the interaction between brain cancer status and treatment on outcomes (rVTE, MB, and CRNMB), with a p-value <0.1 indicating a significant interaction.

RESULTS

Of 30,586 patients with active cancer (5 % had brain cancer), apixaban (vs. LMWH and warfarin) was associated with lower risk of rVTE, MB, and CRNMB. Generally, no significant interactions (P > 0.1) were found between brain cancer status and anticoagulant treatment across outcomes. The exception was MB for apixaban [vs LMWH (p-value for interaction = 0.091)] with a higher reduction among those with brain cancer (HR = 0.32) than those with (HR = 0.72) other cancer.

CONCLUSIONS

Among VTE patients with all types of cancer, apixaban (vs LMWH and warfarin) was associated with a lower risk of rVTE, MB, and CRNMB. In general, anticoagulant treatment effects were not significantly different between VTE patients with brain cancer and those with other cancer.

Effectiveness and Safety of Direct Oral Anticoagulants Among Octogenarians with Venous Thromboembolism: An International Multidatabase Cohort Study

BACKGROUND

The effects of direct oral anticoagulants (DOACs) among octogenarian patients with venous thromboembolism remains poorly understood. To address this knowledge gap, our study aimed to assess the effectiveness and safety of DOACs compared to vitamin K antagonists (VKAs) among octogenarians with venous thromboembolism.

METHODS

We conducted an international cohort study using administrative health care databases from Québec, Canada, and Germany. We assembled 2 population-based cohorts of octogenarians with incident venous thromboembolism initiating treatment with DOACs or VKAs. The study period spanned from January 2012 to the most recent date of data availability (Québec: December 2016; Germany: December 2019). Using an as-treated exposure definition, we compared use of DOACs to use of VKAs, applying inverse probability of treatment weighting based on high-dimensional propensity scores to balance exposure groups. Cox proportional hazards models estimated site-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of recurrent venous thromboembolism, major bleeding, and all-cause mortality. The results were meta-analyzed using random-effects models.

RESULTS

Overall, our study included 6737 octogenarians with venous thromboembolism (Québec: n = 2556; Germany: n = 4181) who initiated use of DOACs (n = 3778) or VKAs (n = 2959). When compared to VKAs, DOACs were associated with similar risks of recurrent venous thromboembolism (weighted HR, 0.80; 95% CI, 0.43-1.46; I² = 0.00), major bleeding (weighted HR, 0.96; 95% CI, 0.57-1.63; I² = 0.59), and all-cause mortality (weighted HR, 1.04; 95% CI, 0.81-1.34; I² = 0.00).

CONCLUSIONS

Among octogenarians with venous thromboembolism, DOACs showed a comparable effectiveness and safety compared to VKAs. Our results support the use of DOACs in this high-risk group.

A Systematic Review of the Guidelines on Venous Thromboembolism Prophylaxis in Gynecologic Oncology

(1) Background: This review aimed to summarize the indications for venous thromboembolic (VTE) events' prophylaxis in a gynecological cancer population, according to the most recent guidelines. (2) Methods: A systematic review of the guidelines in PubMed, SCOPUS, Web of Science, EMBASE, and CINHAL regarding VTE prevention in gynecological cancer patients was conducted according to PRISMA criteria. We compared the recommendations given by oncological and hematological societies regarding VTE prevention in gynecological cancer patients published from January 2010 through March 2021. We searched for the following keywords: "venous thromboembolism prevention", "cancer", and "guidelines". The AGREE II checklist was used to critically analyze the guidelines' quality. (3) Results: There were 1003 documents available; 14 met the inclusion criteria, 5 were excluded and, eventually, the guidelines of 10 societies were evaluated. (4) Conclusions: The guidelines agree that low-molecular-weight heparin (LMWH) and fondaparinux achieve better results in VTE prevention in gynecological cancer patients. Direct oral anticoagulants (DOACs) can be used to prevent VTE in outpatients and high-risk medical patients after discharge. VTE risk scores should be applied to all oncological patients to identify those who would benefit from a prevention program. More attention should be paid to mechanical prophylactic methods due to the high bleeding risk of gynecological cancer patients.

Effectiveness and safety of direct oral anticoagulants with antiplatelet agents in patients with venous thromboembolism: A multi-database cohort study

BACKGROUND

Patients with venous thromboembolism (VTE) often have comorbidities that require use of antiplatelets. However, evidence on the effects of concomitant use of direct oral anticoagulants (DOACs) and antiplatelets in this high-risk population is scarce. Our international, multi-database cohort study assessed the real-world effectiveness and safety of concomitant use of DOACs and antiplatelets among patients with VTE.

METHODS

We assembled two population-based cohorts using administrative health care databases from Québec and Germany. We included patients with incident VTE who initiated treatment with a DOAC or a vitamin K antagonist (VKA), while being exposed to antiplatelets (acetylsalicylic acid, clopidogrel, ticagrelor, prasugrel, dipyridamole). The study period spanned from 2012 to 2016 (Québec) or 2019 (Germany). Concomitant use of DOACs and antiplatelets was compared with concomitant use of VKAs and antiplatelets, using inverse probability of treatment weighting to balance exposure groups. Cox proportional hazards models estimated site-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of major bleeding, all-cause mortality (primary outcomes), and recurrent VTE (secondary outcome). Site-specific estimates were meta-analyzed using random-effects models.

RESULTS

Overall, 4971 patients with VTE initiated concomitant use of a DOAC (n = 2289) or a VKA (n = 2682) and antiplatelets. Compared with concomitant use of VKAs and antiplatelets, concomitant use of DOACs and antiplatelets was associated with similar risks of major bleeding (HR, 0.81; 95% CI, 0.46-1.45), all-cause mortality (HR, 1.25; 95% CI, 0.87-1.79), and recurrent VTE (HR, 0.96; 95% CI, 0.40-2.27).

CONCLUSIONS

Among patients with VTE using antiplatelets, there were no major differences in effectiveness and safety between DOACs and VKAs.