The purpose of the study was to assess the response rate in children and young adults with ALL/LBL and hypersensitivity to pegaspargase defined as the proportion of subjects having a serum asparaginase activity (SAA) level of ≥ 0.1 IU/mL 14 days following the first IV pegcrisantaspase dose in Course 1. Also, to assess the safety of IV pegcrisantaspase therapy in children and young adults with ALL/LBL with hypersensitivity to pegaspargase.