The Incidence of Hypersensitivity Reactions to Pegylated Asparaginase in Children With Acute Lymphoblastic Leukemia: A City-wide Experience.

Asparaginase (ASNase) is an imperative component of pediatric acute lymphoblastic leukemia (ALL) therapy. Pegylating the ASNase extends its biological half-life in vivo and has become the only ASNase available in the United States for frontline therapy of ALL and lymphoblastic lymphoma. It is either infused intravenously (IV) or injected intramuscularly (IM), administrations of which are associated with hypersensitivity reaction ranging from localized skin reaction to severe anaphylaxis. A retrospective review of 96 medical records of pediatric ALL patients was performed. We compared the incidence of hypersensitivity reaction associated with IV versus IM administration of pegylated ASNase. Ninety-one patients were included in the final analysis; 31 having received pegylated ASNase IV and 60 receiving it IM. The incidence of any grade ≥ 2 hypersensitivity reaction in patients who received IV ASNase was 32.2% compared with 13.3% in the IM group (P=0.032). There was no difference in higher grade hypersensitivity reactions (19.4% vs. 11.7%). Most reactions tended to occur during periods of leukemia therapy that did not include concomitant steroid therapy. Our retrospective analysis indicates that IV administration of pegylated ASNase increases the incidence of low-grade, but not grade 3-4, hypersensitivity reactions compared with IM administration.