Toxicities of Intravenous (IV) Pegasparaginase (ONCASPAR®) in Adults with Acute Lymphoblastic Leukemia (ALL).

Background: With the multiple reports of asparaginase-containing regimens used in pediatric ALL therapy achieving a greater survival rate that non-asparaginase treatment regimens used in adult patients, asparaginase therapy is now being increasingly applied in chemotherapy regimens for adults with ALL. One reason for this resurgence is the availability of a long-acting form of the enzyme, pegylated asparaginase, and more recently, flexibility in administration of pegasparaginase via either intramuscular or intravenous routes (Oncaspar®). Given an initial impression in the 1970s that adults were more vulnerable to the toxicities of asparaginase than were children, we assessed the initial experience of intravenous asparaginase in adults with ALL.

Methods: The intial experience with pegylated asparaginase at the University of Southern California (USC), Cleveland Clinic, and University of Texas M.D. Anderson Cancer Center were compiled and compared between institutions and with published results in pediatric patients.

Results (Table): In 76 adult patients administered 192 doses of pegasparaginase in combination with other chemotherapy agents for ALL, hepatotoxicity was most common, with grade 3–4 elevation of serum liver enzymes and grade 3–4 hyperbilirubinemia in 36% and 14% of the patients, respectively. Hyperglycemia and chemical pancreatitis were next most common, having occurred at grade 3–4 levels in 25% and 5% of patients, respectively. Grade 3–4 toxicities in the 5–10% range were thrombosis, hypofibrinogenemia, nausea/vomiting, and fatigue. Grade 3–4 allergy/hypersensitivity, neuropathy, and CNS ischemia were reported in 1–5% of patients.

Conclusions: Intravenous pegasparaginase is hepatotoxic in ∼1/3 of adult patients and has a variety of other, non-hepatic toxicities in <10% of patients, of which the most common are pancreatitis, thrombosis, nausea/vomiting and fatigue. Intravenous pegasparaginase has a toxicity profile, in combination with other chemotherapy agents used in ALL therapy, in adult patients that similar to that in pediatric patients, and warrants increased use in adult patients with ALL.