Clinical Outcomes of Multiple Myeloma Patients Treated with Direct Oral Anticoagulants for Immunomodulatory Drug Associated Venous Thromboembolism

• Published in: Blood 2019-11, Vol.134 (Supplement_1), p.4964-4964
• Main Authors: Crowther, Zachary, Doyle, Jamie, Taylor, Stanford, Ali, Nadia
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2019-131396

Introduction: Venous thromboembolism (VTE) is a common complication in multiple myeloma (MM) patients for several reasons; hematologic malignancy itself is a VTE risk factor and standard of care immunomodulatory drugs (IMiDs) in combination with dexamethasone (Dex) increase the risk further. This combination therapy has a mean VTE incidence of 21.5% in studies that did not use thromboprophylaxis and is recommended for all patients on IMiDs, although the optimal thromboprophylactic regimen remains uncertain. In clinical practice, aspirin (ASA) is commonly prescribed for VTE prophylaxis due to the ease of use. Despite this, the incidence of VTE remains between 7-14%. There is a growing body of literature supporting the efficacy and safety of direct oral anticoagulants (DOACs) for the treatment of VTE in cancer populations. We wanted to assess the incidence of VTE despite ASA prophylaxis at our institution and to further characterize the role of DOACs in the MM population. To do this, we performed a chart review of all MM patients who had been treated with lenalidomide and a DOAC, assessing for VTE development and patient outcomes. Methods: We conducted a retrospective chart review of patients with the diagnosis of MM treated with lenalidomide therapy at Fox Chase Cancer Center at Temple University Hospital or Cottman Avenue after Jan 1st, 2015 to July 2019. Eligible patients were identified through electronic medical record data mining for patients that had been diagnosed with MM, had been prescribed lenalidomide, had been taking ASA while on lenalidomide, and switched to rivaroxaban, edoxaban or apixaban. For comparison, the number of patients treated with lenalidomide and ASA who did not switch to a DOAC were also identified. Patient charts were reviewed for VTE development and bleeding complications after DOAC administration. Results: 132 patients were identified who had a diagnosis of MM and had been prescribed lenalidomide between Jan 1, 2015 and July 31, 2019. These patients were also prescribed aspirin except for three who were already on a DOAC prior to starting lenalidomide. Of the total 132 patients, only 17 were prescribed a DOAC. Six of the patients were on DOACs for reasons other than VTE (atrial fibrillation N=4, atrial flutter N=1, marantic endocarditis N=1). Eleven patients were started on DOACs for VTE; incidence of 8.3% in our myeloma population. However three of these VTEs occurred within one month of high dose melphalan chemotherapy and a