Use of direct oral anticoagulants in patients on immunomodulatory agents

Immunomodulatory agents (IMiDs) are used to treat multiple hematologic malignancies. Their use is also associated with increased risk of venous thromboembolism (VTE). Direct oral anticoagulants (DOACs) have been increasingly utilized but due to their relative novelty, their role in malignancy has only been recently investigated. The objective of this study was to assess the safety and efficacy of DOACs in patients receiving IMiDs. This was a retrospective study of patients at our institution treated with an IMiD and concomitant warfarin or DOAC between January 1, 2010 and December 31, 2015. Information on demographic and clinical characteristics was collected. Separate encounters were collected for each specific combination of IMiD and anticoagulant. Bleeding and thrombotic events were recorded. There were four bleeding events in the DOAC group; all were non-major. There were six bleeding events in the warfarin group, two of which were major (gastrointestinal bleeding (GIB) and subarachnoid hemorrhage (SAH)) and four of which were non-major. Of the two major bleeds in this group, neither event occurred with concomitant antiplatelet therapy. There was one thrombotic event in the DOAC group, which was a myocardial infarction, suspected to be related to carfilzomib. There were no thrombotic events in the warfarin group. This was a retrospective, single-institution study assessing the safety and efficacy of DOACs as compared to warfarin in patients on IMiDs. DOACs may represent an attractive alternative to warfarin for VTE prophylaxis in patients on IMiDs but prospective studies in this population are warranted.