Prophylactic therapy with enoxaparin during L-asparaginase treatment in children with acute lymphoblastic leukemia

Forty-one consecutive children with acute lymphoblastic leukemia (ALL) rece ived prophylaxis therapy with the low molecular weight heparin (LMWH) enoxa parin during L-asparaginase treatment. Enoxaparin was given every 24 h subc utaneously at a median dose of 0.84 mg/kg per day (range, 0.45-1.33 mg/kg p er day) starting at the first dose of L-asparaginase until I week after the last dose. Molecular analysis for thrombophilic polymorphisms documented p rothrombin G20210A mutation in 3/27 (11%), homozygosity for MTHFR C677T mut ation in 5/27 (18.5%, and heterozygosity for factor V Leiden mutation in 5/ 27 (18.5%) children. There were no thrombotic events during 76 courses of L -asparaginase in 41 patients who had received enoxaparin. One patient suffe red brain infarct 7 days after enoxaparin was stopped. There were no bleedi ng episodes. In a historical control group of 50 ALL children who had not r eceived prophylactic enoxaparin during L-asparaginase treatment, two had th rombo embolisms (one deep vein thrombosis and one pulmonary embolism). Enox aparin is safe and seems to be effective in prevention of thromboembolism i n ALL patients during L-asparaginase therapy. This study provides pilot dat a for a future randomized trial of the use of LMWH during ALL therapy for t he prevention of asparaginase-associated thrombotic events. (C) 2001 Lippin cott Williams & Wilkins.