Antithrombin supplementation did not impact the incidence of pegylated asparaginase-induced venous thromboembolism in adults with acute lymphoblastic leukemia.

Pegylated asparaginase (PEG-Asp), a key component in the treatment of acute lymphoblastic leukemia (ALL), is associated with coagulopathy and an increased risk of venous thromboembolism (VTE). PEG-Asp also lowers antithrombin (AT) levels. Between April 2014 and October 2017, 75 adult ALL patients were identified to have received at least one dose of PEG-Asp. Patients were assigned to the AT group if a physician monitored AT levels with an intention to correct low AT levels (<60%). Incidence of VTE was not significantly different, with 17% (8/47) of the AT patients and 11% (3/28) of the control patients experiencing a VTE event (p = .52). The occurrence of coagulopathies was not significantly different. Within the AT group, 37 patients (78%) received AT, and median AT% prior to supplementation was 49%. The median number of AT doses received was 2 (range 0-12) and the mean cost of AT per patient was $11,847.