PB2282 REASSESSING THE EFFICACY OF LOW DOSE RASBURICASE FOR MANAGEMENT OF TUMOR LYSIS SYNDROME IN HIGH RISK HEMATOLOGIC MALIGNANCIES

Abstract

Background:Tumor lysis syndrome (TLS) is a potentially life‐threatening metabolic derangement seen in aggressive hematologic malignancies which is characterized by the massive release of toxic metabolic byproducts and consequent kidney damage. Whereas rasburicase is an established standard of care for management of TLS, the high cost of administering standard dosing of rasburicase has led to exploring lower doses of rasburicase.Aims:Assess our center's experience with lower dosing of rasburicase for management of TLS in aggressive hematologic malignancies.Methods:We studied all adult patients with hematologic malignancies who were treated with rasburicase in our institution between the years 2011‐2018. Charts were reviewed and demographic, clinical, and laboratory data were collected. Subjects were defined to be at high risk for TLS if they had any of the following features: acute leukemia, elevated uric acid levels at baseline (>7.5 mg/dL) or aggressive lymphoma.Results:Fifty‐five patients were evaluated. The median age of patients was 67 years (range 22‐92) consisting of 20 patients with acute leukemia, 21 with aggressive lymphoma, 11 with multiple myeloma, and 3 with other hematologic cancers. Nearly all analyzed patients (98%) were considered to be at high risk for TLS and 44 patients did meet criteria for clinical TLS. Twenty‐six patients (47%) received allopurinol prophylaxis. The median dose of rasburicase administered was 3 mg (range 1.5‐9) with 10 patients being given a second dose of rasburicase. The median baseline levels of uric acid and creatinine were 13.9 mg/dL (range 6.5‐42.8) and 2.18 mg/dL (range 0.63‐8.15), respectively. At 24 hours post administration of rasburicase the median uric acid levels were 7.9 mg/dL (range 0.8‐17.5) while at 48 hours they were 4.9 mg/dL (range 0.8‐13.5). Notably, 54 patients (98%) experienced a decrease in uric acid levels of at least 10% within the first 24 hours following rasburicase administration and 40% of patients had normal uric levels by that time. Within the initial 24 hours, creatinine levels were significantly improved in only a minority of patients with only 10 patients (18%) experiencing a decrease of more than 10% compared to baseline levels. Of note, 15 patients required dialysis during their admission and 26 patients died during the index hospitalization.Summary/Conclusion:The majority of subjects in our analysis of a high‐risk patient population responded favorably to low dose rasburicase in terms of rapid uric acid reduction although rates of dialysis and early mortality were substantial. Our data illustrate and confirm the feasibility of lower dosing of rasburicase to patients with aggressive hematologic malignancies.