Pb2179 thromboembolic events in multiple myeloma (mm) patients. a single center retrospective study

Background: MM affects mainly patients older than 65 years. These patients are at higher risk for venous thromboembolism (VTE) because of cancer status, intrinsic risk factors and exposure to prothrombotic therapies. The risk of VTE appears higher during the first months of MM treatment (3‐4%). Exposure to immunomodulatory drugs (IMDs) such as Lenalidomide and Thalidomide in association with high dose dexametasone (HD‐DXM) or anthracyclin‐based chemotherapy is associated with increased risk of VTE (26%). There are recommendations available to guide the use of thromboprophylaxis in MM patients but progress on determining the most effective and safe strategy is low. In general, Low molecular weight heparin (LMWH) or therapeutic dose warfarin is recommended for patients the receive doxorubicin, HD‐DXM or multiagent chemotherapy, but thromboprophylaxis management is often complicated due to impaired renal function thrombocytopenia and increased bleeding risk. Aims: The goal of this single center retrospective study is to evaluate and characterize the VTE episodes in MM patients in our institution. Methods This single center retrospective study analyzes 84 MM patients diagnosed and treated in our center between 2008 and 2018 and describe the characteristics of 14 VTE episodes in 12/84 patients. Most of patients were assessed for risk factors, individual and related to MM, with Palumbo et al. Risk assessment model (Leukemia 2008;22:414‐23). Results: Main characteristics of the 12/84 MM patients diagnosed with 14 VTE episodes are shown in Table 1. 4/12 (33%) are female and median age is 69 years old (49‐85). 2/12 (16%) patients present 2 episodes of VTE. 4/12 (33%) patients receive thromboprophilaxis with LMWH, 6/12 (50%) with AAS, while 3/12 (25%) do not have profilaxis. 3/14 (21%) VTE episodes present at the moment of diagnosis, 4/14 (28,5%) in the first months of diagnosis during hospitalization for infection or uncontrolled MM disease. All VTE episodes are diagnosed under MM treatment: 9/14 (64%) Lenalidomide+ HD DXM. 1/14 (7%) chemotherapy (DTPACE), 3/14 (21,4%) proteosome inhibitors combination. 1/14 (7%) Daratumumab‐Bortezomib‐Dexametasone. 5/14 (35%) VTE are superficial vein thrombosis (SVT), 5/14 (35%) pulmonary embolism (PE), 3/14 (21%) VTE + PE, 1/14 (7%) renal thrombosis. In all patients VTE treatment is done with HBPM during 3 o 6 months. Summary/Conclusion: In our institution the incidence of VTE in MM patients is 16%. image In our experience the use of IMWG assement risk does not eliminate the rate of VTE in these patients. It may be reasonable to start preventive doses of LMWH for 3 to 6 months in ambulatory MM patients receiving combined therapy with IMIDs and in all mieloma patients admited to the hospital. New risk assessment models combining clinical factors and hipercoagulability biomarkers shoud be developed. New trials are needed to explore safe thromboprophylaxis in MM patients (direct thrombin inhibitors or factor Xa inhibitors).