Pegaspargase, trade name Oncaspar, mainly is a modified enzyme considered as an antineoplastic agent. It is a form of L-asparaginase which has undergone PEGylation. The pegaspargase injection is used in the treatment of acute lymphoblastic leukemia. As an enzyme it interferes with natural substances required for malignant cell growth. It works by destroying/inhibiting the progression of cancer cells. Pegaspargase is available as a liquid to be injected into a muscle or infused intravenously (into a vein) over 60/120 minutes by a health specialist in a medical office or hospital outpatient clinic.