Comparative effectiveness of rasburicase versus allopurinol for cancer patients with renal dysfunction and hyperuricemia.

While rasburicase has shown efficacy to rapidly correct hyperuricemia compared with allopurinol, its overall impact in improving clinically significant outcomes, such as acute kidney injury (AKI), in tumor lysis syndrome (TLS) is unknown. In this retrospective cohort study, we included all hospitalized cancer patients with hyperuricemia and AKI who received rasburicase +/- allopurinol or allopurinol alone from 2009 to 2015. Inverse probability of treatment weighting using propensity score was used to account for potential confounders and to estimate the causal effect associated with differential drug treatment. 150 patients met inclusion criteria; 89 received rasburicase +/- allopurinol and 61 received allopurinol alone. Weighted outcome regression analysis demonstrated that rasburicase was associated with significantly lower mean uric acid nadir at 7 days compared to allopurinol (2.70 versus 5.82 mg/dL, p < 0.01). However, likelihood of renal function recovery (OR = 0.90, p = 0.79), creatinine nadir by 7 days (1.80 versus 1.66 mg/dL, p = 0.51), and final creatinine by 30 days (2.08 versus 2.07 mg/dL, p = 0.98) did not significantly differ. In conclusion, the clinical benefit of rasburicase in promoting renal function recovery in cancer patietns with concurrent hyperuricemia and renal failure remains inconclusive. Our results suggest that correction of hyperuricemia as a surrogate endpoint may not be associated with significant renal function improvement, particularly if renal dysfunction is unrelated to TLS.