PEG-Asparaginase is a conjugated preparation E. coli L’Asparaginase where polyethylene glycol is covalently linked to the enzyme. It is induced in the treatment of acute lymphoblastic leukemia (ALL) as a component of multi-agent chemotherapy in pediatric and adult patients. This drug is used in patients that have a hypersensitivity reaction to L’Asparaginase and develop anti-asparaginase antibodies, which neutralize their activity.  Relative to E. coli L’Asparaginase, PEG-Asparaginase has a prolonged circulation time in the blood, thereby offering less frequent administration.

The mechanism of action however mimics L’Asparaginase where the administration of L’Asparaginase leads to the depletion of an important nutrient asparagine (amino acid) in cancer cells, thus leading to starvation of cells and subsequent cell death. Given the advantages over E. Coli Asparaginase, PEG-Asparaginase is an effective treatment option for patients with ALL, including those with hypersensitivity to E. Coli Asparaginase.