Background: Venous thromboembolism (VTE) is a known complication in adults receiving asparaginase (ASNase) for acute lymphoblastic leukemia (ALL). We previously reported a 27.3% VTE rate in patients (pts) receiving a modified Dana Farber Cancer Institute (DFCI).We report updated results using two different dosing of enoxaparin as primary VTE prophylaxis. Methods: 62 pts ALL in complete remission, who were treated with a weekly ASNase-based DFCI intensification phase for at least 7 cycles (21 weeks) and received prophylaxis with enoxaparin targeted to 1 mg/kg subcutaneously (SC) daily (escalated dose group), were evaluated . Results were compared to a similar group of 41 patients who had received enoxaparin 40 mg for patients weighing less than 80 kg, and 60 mg for those 80 kg and above (low-dose group), and to a similar group of 99 pts previously treated with the same DFCI protocol without anticoagulation prophylaxis. Results: The actual mean dose of enoxaparin in the low-dose prophylaxis group was 0.62 mg/kg, as compared to 0.88 mg/kg in the escalated dose group. There were no major bleeding complications observed in the prophylaxis groups. The minor bleeding rate in the entire prophylaxis cohort was 4.8% (5/103), and was similar between the low-dose and escalated dosing groups. The VTE entire cohort that received prophylaxis was 20% (21/103). The VTE rates for all groups as shown in the table. Conclusions: Overall use of prophylactic enoxaparin during intensification in adults with ALL receiving ASNase was safe; escalating the enoxaparin dose to 1 mg/kg, did not increase the number of bleeding events. There was a trend toward a lower rate of VTE using dose-escalated enoxaparin, particularly in patients weighing < 80 kg.

* comparing No vs ALL prophylaxis