Thromboembolic events with lenalidomide-based therapy for multiple myeloma

BACKGROUND. The purpose was to evaluate the incidence and risk factors of thromboembolism associated with lenalidomide therapy in newly diagnosed myeloma. METHODS. A pooled analysis was performed of patients with previously untreated multiple myeloma enrolled in clinical trials of lenalidomide-based therapy at the Mayo Clinic, Rochester, Minnesota, and the Italian Myeloma Network, Italy. The incidence of thrombosis, the effect of risk factors such as steroid dose and erythropoietin supplementation, and the effect of prophylaxis were examined. RESULTS. In all, 125 patients enrolled in 3 clinical trials were identified. Patients were stratified based on the concomitant corticosteroid dose. Fifty-two patients were in the high-dose group (dexamethasone 40 mg, 12 days a month); 73 patients were in the low-dose group (prednisone at any dose; or dexamethasone 40 mg, 4 days a month). A total of 110 patients were initiated on thromboprophylaxis; of these, 104 patients (95%) received aspirin. Ten patients (8%) developed deep vein thrombosis, including 4 who were not receiving any thromboprophylaxis at the time of the event. The rate of thromboembolic events was not different between patients who received concomitant erythropoietin therapy and those who did not, 4.8% and 8.6%, respectively (P = .54). A higher number of venous thrombotic episodes occurred in the high-dose corticosteroid group compared with the low-dose corticosteroid therapy group (12% vs 6%), but the difference was not statistically significant (P = .3). CONCLUSIONS. The incidence of deep vein thrombosis is lower than previously reported in the literature. There was a trend to a higher incidence of thrombosis in patients receiving high-dose corticosteroid therapy.