Comparative outcomes of prophylactic anticoagulation in patients with multiple myeloma receiving immunomodulatory therapy.

Abstract

e19542 Background: Patients with multiple myeloma have a substantially increased risk of venous thromboembolism (VTE), further amplified among those receiving immunomodulatory drug-based (IMiD) therapy, particularly early in treatment and with other prothrombotic agents. Direct oral anticoagulants (DOACs) and low–molecular-weight heparin (LMWH) are commonly used for thromboprophylaxis, but comparative real-world outcome data remain limited. Methods: We conducted a retrospective cohort study using the TriNetX Research Network of adults with multiple myeloma initiating IMiD therapy who received prophylactic anticoagulation with a DOAC (apixaban, rivaroxaban, edoxaban, or dabigatran) or LMWH (dalteparin or enoxaparin) within one month of diagnosis and IMiD initiation. Patients with prior VTE were excluded. Cohorts were matched 1:1 using propensity scores. Outcomes included VTE, all-cause mortality, and major bleeding at 1 year. A lenalidomide-restricted sensitivity analysis was performed. Results: After propensity score matching, 699 patients per group were included. At 1 year, all-cause mortality occurred in 74 patients (10.6%) receiving DOACs and 117 patients (16.8%) receiving LMWH (HR 0.59, 95% CI 0.44–0.79; p=0.005). There were no significant differences in VTE or major bleeding. In a lenalidomide-restricted sensitivity analysis, DOAC use remained associated with lower 1-year mortality compared with LMWH (7.7% vs 17.0%; HR 0.42, 95% CI 0.29–0.61; p<0.001), among 533 patients per cohort. Conclusions: In this real-world cohort of patients with multiple myeloma receiving IMiD-based therapy, DOAC prophylaxis was associated with lower 1-year all-cause mortality compared with LMWH, with no significant differences in VTE or major bleeding. These findings support further prospective studies to define optimal thromboprophylaxis strategies in this population. Outcomes at 1 year after propensity score matching (n = 699 per cohort). Outcome (1-year) DOAC (n=699) LMWH (n=699) HR (95% CI) P value All-cause mortality 10.6% 16.8% 0.59 (0.44–0.79) 0.005 Venous thromboembolism (PE or DVT) 7.5% 7.1% 1.02 (0.68–1.55) 0.55 Pulmonary embolism 3.4% 3.2% 1.01 (0.56–1.82) 0.051 Deep venous thrombosis 4.8% 5.1% 0.90 (0.57–1.51) 0.24 Major bleeding (ICH or GI bleed) 2.6% 2.5% 1.00 (0.52–1.94) 0.70 After propensity score matching incorporating age, sex, race, metastatic disease, proteasome inhibitor and systemic corticosteroid therapy, underlying comorbidities, and history of critical illness or intensive care unit admission.