Direct oral anticoagulants versus aspirin for primary thromboprophylaxis in patients with multiple myeloma undergoing outpatient therapy: A systematic review and updated meta-analysis

Patients with multiple myeloma (MM) are at an elevated risk of venous thromboembolism (VTE), which is further increased for those undergoing anti-myeloma therapy. Current guidelines suggest low-dose direct oral anticoagulants (DOACs) as an alternative to aspirin for primary thromboprophylaxis in this population, but data comparing these two therapies are limited. We performed a systematic review and meta-analysis to compare DOACs with aspirin for primary thromboprophylaxis in individuals undergoing outpatient anti-myeloma therapy. Studies were selected when comparing DOACs versus aspirin for thrombotic and haemorrhagic outcomes. We included 10 randomised controlled trials and observational studies comprising 1026 patients with MM who received primary thromboprophylaxis with DOACs (n = 337) or aspirin (n = 689). DOAC thromboprophylaxis was associated with a significantly lower incidence of VTE compared with aspirin (OR 0.33; 95% CI 0.16–0.68; p < 0.001). Major, clinically relevant non-major and minor bleeding event rates did not differ significantly between groups. Overall, our meta-analysis suggests that DOACs may be a preferable option to aspirin for the prevention of MM-related thrombosis. However, these results should be interpreted in the context of heterogeneous baseline population characteristics and potential bias from including observational studies. Further research is needed to evaluate the optimal thromboprophylaxis strategy, particularly in high-risk individuals.