Josep-Maria Ribera, MD, PhD, of the Germans Trias I Pujol University Hospital, Barcelona, Spain explains his study which compared the efficacy and safety of native and pegylated asparaginase for the treatment of adult high-risk (HR) Philadelphia (Ph) chromosome-negative acute lymphoblastic leukemia (ALL). The study found that the two types of E. coli asparaginase have similar efficacy in immediate and long-term response. However, in terms of safety, slightly differing toxicity patterns were found with native asparaginase associated with a higher frequency of allergic reaction, and the pegylated asparagine associated with more liver toxicity. Recorded at Recorded at the 2016 American Society of Hematology (ASH) Annual Meeting, held in San Diego, CA.