Effect of lenalidomide use as part of induction chemotherapy on the risk of peri-transplant venous thromboembolic events (VTE) in patients undergoing autologous stem cell transplant for multiple myeloma.

Abstract

e19524 Background: Lenalidomide (len) is approved for treatment in Multiple Myeloma (MM) Use of len has been associated with an increase in venous thrombotic events (VTE) and aspirin prophylaxis is recommended for pts who are on active treatment with len. Autologous stem cell transplant (ASCT) is used during the treatmentof MM after initial induction therapy. The use of intravenous catheters and hospitalization increase the risk of VTE in peri-transplant period. We evaluated the incidence of VTE in peri-transplant period to determine if len use increased the risk of VTE. Methods: We performed a retrospective chart review of pts with MM who underwent first ASCT at our institution between 1/2011-1/2015.Data was collected on pt. demographics, len use, VTE prophylaxis, VTE incidence and VTE treatment. Chemical anticoagulation during the peri-transplant period was based on physician preference and chemical anticoagulation was stopped once platelet counts dropped below 50,000/ uL. All pts were encouraged to ambulate daily for mechanical prophylaxis. Associations with incidence of VTE were conducted by univariable and multivariable logistic regression analyses. Results: A total of 303 pts met the study criteria. 204 pts received Len as part of induction treatment while 99 did not. There was no significant difference in demographics of the 2 groups. 87% pts in the Len group and 81% in the non-Len group did not receive any chemical prophylaxis, respectively during hospitalization. 15 pts developed DVT within 100 days of transplant: 10 in len group and 5 in non-len group (p > 0.99). 14 of the 15 were catheter associated. Median time to DVT was 10.5 days post-transplant. Caucasians had a higher risk of DVT; adjusted OR 0.315 (95%CI 0.03-0.99; p = 0.046). Incidence of VTE was not affected by prophylaxis, or response to induction. Conclusions: Despite the fact that during the peri-transplant period most of the patients were not on prophylactic chemical anticoagulation due to chemotherapy associated thrombocytopenia len use during the induction treatment did not increase the risk of peri-transplant VTE.