A Randomized Double-Blind Phase Iii Pivotal Study Of Febuxostat (Feb) Versus Allopurinol (All) In The Prevention Of Tumor Lysis Syndrome (Tls): Florence Study.

9641^ Background: Tumor lysis syndrome (TLS) is an oncologic emergency characterized especially by elevated serum uric acid (sUA). FEB is an orally administerd selective xanthine oxidase inhibitor to reduce sUA. Methods: This was a randomized, double blind phase III trial of FEB vs ALL in terms of control of sUA level and preservation of renal function in patients undergoing chemotherapy (CT) for hematologic malignancies at intermediate to high risk of TLS. Patients werestratified according to TLS risk and sUA level to FEB or ALL starting from 2 days prior CT and continued for 7-9 days. Assigned treatment was blinded, while daily dose level (low/standard/high containing ALL 200/300/600 mg or fixed FEB 120) was upon investigator’s choice. Primary endpoints were sUA area under the curve (AUC sUA1-8) and change in serum creatinine (sC) level both from baseline to Day 8, analyzed through ANCOVA including treatment and stratification factors as covariates. Secondary endpoints were response rate (sUA ≤ 7.5 mg/d...