Hemostatic effects of bortezomib treatment in patients with relapsed or refractory multiple myeloma

Due to increased baseline hypercoagulability, subjects with multiple myeloma (MM) are at increased risk of developing venous thromboembolism (VTE) compared with the general population.1 Both thalidomide and lenalidomide treatment have been associated with an increased thrombogenecity,2 however, this was not associated with shorter overall survival.3 Pre-clinical and clinical reports have suggested a possible anti-thrombotic effect of bortezomib.4,5 We report the first study which prospectively describes in vivo effects of bortezomib on routine tests of blood coagulation and platelet function in MM treated patients. Patients with relapsed /refractory multiple myeloma who failed one line of prior therapy were eligible for the study. After obtaining informed consent approved by the local institutional review board, bortezomib-naïve patients with relapsed/refractory MM were enrolled in the study. Upon enrollment, subjects were required to have a normal prothrombin time (PT) and partial thromboplastin time (PTT) and a platelet count >100×109/L.