Apixaban thromboprophylaxis in ambulatory patients with cancer and obesity: Insights from the AVERT trial.

Background: The use of direct oral anticoagulants (DOACs) in obese patients is uncertain. It is unclear if body mass index (BMI) affects the safety and efficacy of DOACs for the primary prevention of venous thromboembolism (VTE) in high-risk ambulatory patients with cancer. We sought to determine the outcomes associated with the use of apixaban for the primary prevention of cancer-associated VTE according to BMI.
Methods: The randomized, double-blinded, placebo-controlled AVERT trial evaluated apixaban thromboprophylaxis in intermediate-to-high risk ambulatory cancer patients receiving chemotherapy. For this post-hoc analysis, the primary efficacy and safety outcomes were objectively confirmed VTE and clinically relevant bleeding (major and clinically relevant non-major bleeding), respectively. Obesity was defined as BMI ≥30 kg/m ² .
Results: Among 574 patients randomized, 217 (37.8 %) patients had BMI ≥30 kg/m ² . Obese patients were overall younger, more likely to be female, had higher creatinine clearance and hemoglobin, lower platelet count, and better ECOG performance status. Compared to placebo, apixaban thromboprophylaxis was associated with reduced VTE in both obese (hazard ratio [HR] 0.26; 95 % confidence interval [CI], 0.14-0.46; p < 0.0001) and non-obese (HR 0.54; 95%CI, 0.29-1.00; p = 0.049) patients. The HR for clinically relevant bleeding (apixaban vs. placebo) was numerically higher in obese (2.09; 95%CI, 0.96-4.51; p = 0.062) than non-obese subjects (1.23; 95%CI, 0.71-2.13; p = 0.46), but overall in line with the risks observed in the general trial population.
Conclusions: In the AVERT trial enrolling ambulatory cancer patients receiving chemotherapy, we found no substantial differences in the efficacy or safety of apixaban thromboprophylaxis across obese and non-obese subjects.
Competing Interests: Declaration of competing interest N. Potere has received a training fellowship from the International Society on Thrombosis and Haemostasis, and research funding from the International Network of VENous Thromboembolism Clinical Research Networks (INVENT). M. Di Nisio has received personal fees as an invited speaker from Bayer, Daiichi Sankyo and Viatris, personal fees for advisory board membership from LEO Pharma and Pfizer, and institutional funding from LEO Pharma. TF. Wang reports advisory board honoraria from Servier and Valeo, and research funding to the institution from Leo Pharma. M. Carrier has received research funding from BMS, Pfizer, and Leo Pharma, and honoraria from Bayer, Pfizer, BMS, Servier, and Leo Pharma. A. Delluc reports grants from Leo Pharma and Pfizer, personal fees from BMS, Leo Pharma, Pfizer, Servier. R. Mallick, P. Wells, V. Tagalakis and S. Shivakumar have no relevant conflicts of interest to disclose.
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