Tolerability and toxicity of pegaspargase in adults 40 years and older with acute lymphoblastic leukemia

Pegaspargase is a modified version of asparaginase with prolonged asparagine depletion. It appears to be safe in adults <40 years old, but has a unique spectrum of toxicities, the risks of which appear to increase with age. The primary objective of this study was to evaluate pegaspargase tolerability and toxicity as assessed by evaluation of incidence and severity of adverse events. Secondary objectives included characterization of the reasons underlying pegaspargase discontinuation, when applicable. Grade 3/4 asparaginase-related toxicities with ≥10% incidence included: hyperbilirubinemia, hyperglycemia, hypertriglyceridemia, hypoalbuminemia, hypofibrinogenemia, and transaminitis. 63% of patients (38 of 60) received all intended doses of pegaspargase, with the most common reasons for discontinuation noted as hypersensitivity (12%), hyperbilirubinemia/transaminitis (8%), and hematopoietic transplantation in complete remission (10%). This study suggests that while hepatotoxicity and other known adverse effects are common, with careful monitoring, pegaspargase can safely be administered to adults with ALL age ≥40 years old.