Bleeding risk from anticoagulant thromboprophylaxis in patients with multiple myeloma: a MarketScan analysis

Essentials•After median follow-up of 1.3 years, 1.4% of patients on thromboprophylaxis had severe bleeding.•Rate of severe bleeding in patients receiving thromboprophylaxis was 7.8 per 1000 person-years.•Bleeding rates are similar between myeloma patients on and off anticoagulant thromboprophylaxis.•Clinical factors including hypertension and renal disease increased bleeding risk.AbstractBackgroundMultiple myeloma (MM) is associated with high risk of venous thromboembolism (VTE). Anticoagulant prophylaxis is frequently recommended but underutilized partly due to the absence of studies assessing bleeding risk.ObjectivesTo determine the rate of severe (hospitalized) bleeding from thromboprophylaxis in patients treated for MM and identify clinical risk factors for bleeding in this population.MethodsUsing the MarketScan database, we analyzed 6656 patients treated for MM between 2013 and 2021. Concomitant thromboprophylaxis was defined using prescription claims. Hospitalized bleeding was identified through the Cunningham algorithm. Bleeding rates were compared by thromboprophylaxis status, and Cox regression identified risk factors for bleeding.ResultsAnticoagulant thromboprophylaxis was used in 6.6% (436) patients treated for MM. Patients on thromboprophylaxis had a higher rate of immunomodulatory-based therapy (63.8% vs 46.7%; P < .01) and lower rate of antiplatelet use (2.1% vs 4.7%; P < .01). Bleeding occurred in 1.4% of them during median follow-up of 1.3 years. Rate of severe bleeding was not different between those on prophylaxis (7.8 per 1000 person-years) and those not on prophylaxis (10.1 per 1000 person-years). No association was identified between thromboprophylaxis and bleeding. Factors associated with increased bleeding included age (hazard ratio [HR], 1.38 per 10 years increase in age), comorbidity index (HR, 1.18 per SD increase), history of bleeding (HR, 1.54), hypertension (HR, 1.87), and renal disease (HR, 1.56).ConclusionRisk of serious bleeding from thromboprophylaxis in patients treated for MM was low, and concomitant anticoagulant therapy did not result in increased bleeding risk. Clinical risk factors for bleeding included age, comorbidity index, bleeding history, hypertension, and renal disease.