Comparative Effectiveness Of Rasburicase And Allopurinol In Children With Acute Lymphoblastic Leukemia: An Emulated Pragmatic Trial Using Observational Data

Introduction: Children with newly diagnosed acute lymphoblastic leukemia (ALL) are at risk for developing tumor lysis syndrome (TLS), an oncologic emergency with potentially severe consequences. Effective TLS management centers on prevention, achieved in large part through control of hyperuricemia with allopurinol or rasburicase. Though rasburicase is known to be very effective for children at high TLS risk, there are limited evidence-based data to guide its usage. Currently available guidelines rely on expert opinion and provide conflicting recommendations, especially for patients at intermediate TLS risk. To address this data gap, we emulated a randomized clinical trial (RCT) to test the efficacy of rasburicase in intermediate risk TLS. We hypothesized that rasburicase would not provide benefit for children with ALL who were classified as being at intermediate TLS risk based on white blood cell count (WBC), uric acid (UA), and creatinine (Cr).