The FDA has approved asparaginase Erwinia chrysanthemi (Erwinaze – EUSA), an asparagine-specific enzyme derived from the gram-negative bacillus Erwinia chrysanthemi, for use in combination with other chemotherapeutic agents for treatment of acute lymphoblastic leukemia (ALL) in patients who have had allergic reactions to Escherichia coli-derived asparaginase (Elspar or pegaspargase [Oncaspar]).

ALL is the most common malignancy of childhood. Multidrug chemotherapy can cure about 80% of children with ALL.1 Initial treatment ("induction") usually includes vincristine, a glucocorticoid, and an asparaginase and/or an anthracycline. Inclusion of an asparaginase in ALL regimens improves outcomes, especially in pediatric patients, but approximately 15-20% of patients treated with E. coli-derived asparaginase will develop hypersensitivity to the drug.

In one study, 42 E. coli asparaginase-allergic children with ALL were switched to twice-weekly Erwinia asparaginase 25,000 IU/m² to complete 30 weeks of asparaginase treatment; 81% of patients completed ≥26 weeks of therapy. At a median follow-up of 5.4 years, event-free survival in those children was similar to that of children without E. coli asparaginase allergy (86% vs. 81%). Allergy to Erwinia asparaginase developed in 33% of patients.2