A randomized comparison between rasburicase and allopurinol in children with lymphoma or leukemia at high risk for tumor lysis. A study of rasburicase for the management of hyperuricemia in pediatric patients with newly diagnosed hematologic malignancies at high risk for tumor lysis syndrome. Incidence of tumor lysis syndrome in children with advanced stage Burkitt's lymphoma/leukemia before and after introduction of prophylactic use of urate oxidase. Urate-oxidase in the prevention and treatment of metabolic complications in patients with B-cell lymphoma and leukemia, treated in the Société Française d'Oncologie Pédiatrique LMB89 protocol. Prevention and treatment of hyperuricemia with rasburicase in children with leukemia and non-Hodgkin's lymphoma.
Standard therapy in the United States for malignancy-associated hyperuricemia consists of hydration, alkalinization, and allopurinol. Urate oxidase catalyzes the enzymatic oxidation of uric acid to a 5 times increased urine soluble product, allantoin. Rasburicase is a new recombinant form of urate oxidase available for clinical evaluation. This multicenter randomized trial compared allopurinol to rasburicase in pediatric patients with leukemia or lymphoma at high risk for tumor lysis. Patients received the assigned uric acid-lowering agent for 5 to 7 days during induction chemotherapy. The primary efficacy end point was to compare the area under the serial plasma uric acid concentration curves during the first 96 hours of therapy (AUC(0-96)). Fifty-two patients were randomized at 6 sites. In an intent-to-treat analysis, the mean uric acid AUC(0-96) was 128 +/- 70 mg/dL.hour for the rasburicase group and 329 +/- 129 mg/dL.hour for the allopurinol group (P <.0001). The rasburicase versus allopurinol group experienced a 2.6-fold (95% CI: 2.0-3.4) less exposure to uric acid. Four hours after the first dose, patients randomized to rasburicase compared to allopurinol achieved an 86% versus 12% reduction (P <.0001) of initial plasma uric acid levels. No antirasburicase antibodies were detected at day 14. This randomized study demonstrated more rapid control and lower levels of plasma uric acid in patients at high risk for tumor lysis who received rasburicase compared to allopurinol. For pediatric patients with advanced stage lymphoma or high tumor burden leukemia, rasburicase is a safe and effective alternative to allopurinol during initial chemotherapy. Tumor lysis syndrome (TLS), including hyperuricemia, is a frequent serious complication in patients with hematologic malignancies. This study in Japanese patients evaluated the efficacy, safety, and pharmacokinetic profile of rasburicase in pediatric patients with hematologic malignancies. Patients aged <18 years at high risk for TLS, with newly diagnosed hematologic malignancies, were randomized to intravenous rasburicase 0.15 mg/kg/day (n = 15) or 0.20 mg/kg/day (n = 15) for 5 days. Chemotherapy was started 4-24 h after the first rasburicase dose. Response was defined as a reduction in plasma uric acid to < or = 6.5 mg/dL (patients <13 years) or < or = 7.5 mg/dL (patients > or = 13 years) by 48 h after the first administration, lasting until 24 h after the final administration. Response rates were 93.3 and 100% with rasburicase 0.15 and 0.20 mg/kg/day, respectively. Uric acid levels declined rapidly within 4 h of starting rasburicase administration in both groups. Most adverse events were related to the underlying chemotherapy regimens. Two hypersensitivity reactions, including grade 1/2 pruritus, were considered to be related to rasburicase. Rasburicase is effective and well tolerated for the management of hyperuricemia in Japanese pediatric patients at high risk of developing TLS. To evaluate the clinical benefit of the prophylactic use of urate oxidase in children with non-Hodgkin's lymphoma (NHL), we analyzed the incidence and complications of tumor lysis syndrome (TLS) in children with B-cell acute lymphoblastic leukemia (B-ALL) or stage III/IV Burkitt's lymphoma and a lactate dehydrogenase (LDH) level > or =500 U/l before and after the introduction of a protocol amendment to use urate oxidase for the prophylaxis of TLS. Data from 1791 children with NHL enrolled in the two subsequent multicenter studies NHL-BFM 90 and 95 were evaluated. The presence of the side effects TLS, anuria, sepsis, and other complications during the first 2 weeks after admission were registered. Until March 1996, no urate oxidase was used (period 1). From November 1997 all children with B-ALL or stage III and IV B-NHL and LDH > or =500 U/l should receive urate oxidase prophylactically (period 3). In between (period 2), urate oxidase was given in a minority of hospitals therapeutically. Initial chemotherapy was identical. Altogether, 78 children (4.4%) developed a TLS. Patients with B-ALL had the highest risk to develop a TLS (26.4%) followed by B-ALL/Burkitt's lymphoma and a LDH > or =500 U/l (14.9%). In period 1, 16.1% and 9.2% of the latter children developed a TLS or anuria, respectively, compared to 12.3% and 6.2% in period 3 ( p=NS). The incidence of sepsis remained unchanged (5.0% vs 4.6%). In children with B-ALL the differences in the incidence of TLS and anuria between period 3 and period 1 were more pronounced, reaching significance for anuria (15.4% vs 3.8%, p=0.03). Our results suggest that patients with the highest risk to develop a TLS might benefit from the prophylactic use of urate oxidase. To evaluate the frequency of metabolic complications and dialysis due to tumor lysis syndrome in patients with B-cell advanced-stage non-Hodgkin's lymphoma (NHL) and L3 leukemia at initiation of chemotherapy including the use of urate-oxidase.
                Retrospective review of the clinical records of 410 patients with stage III and IV B-cell NHL and L3 leukemia treated in France and prospectively registered in the LMB89 protocol.
                During the first week of chemotherapy, only 34 of 410 patients recorded metabolic problems that included hypocalcemia (< 70 mg/dl) in 24 patients, hyperphosphatemia (> 6.5 mg/dl) in 28 and elevation of creatinine > or = 2 SD in 16. Six patients underwent dialysis for life-threatening problems and a seventh as a preventive measure. In the other 27 cases, metabolic problems were successfully resolved using urate-oxidase in combination with alkaline hyperhydration. Among the 410 patients, one case of hemolysis was reported and there was no severe allergic reaction to urate-oxidase.
                Only 1.7% of patients in our study receiving urate-oxidase during their induction chemotherapy needed renal dialysis. Urate-oxidase was well tolerated, and used as prophylaxis and/or treatment of hyperuricemia and tumor lysis syndrome consistently gave a lower rate of renal and metabolic complications than in other series of similar patients. To prevent acute renal failure in children at risk for developing tumor lysis syndrome due to acute lymphoblastic leukemia or non-Hodgkin's lymphoma treated according to international BFM protocols, we investigated recombinant urate oxidase (rasburicase) in the first Central European openlabeled, prospective, multicenter phase IV trial. Rasburicase was administered intravenously, at 0.2 mg/kg for 5 consecutive days to 36 patients. Blood levels of uric acid, creatinine, phosphorus, calcium, lactate dehydrogenase and complete blood count were measured daily during rasburicase treatment and on days 6, 7 and 12. Initial uric acid level decreased significantly by 4 hours (from 343 micromol/L to 58 micromol/L, p<0.001), except for one steroid-resistant patient who required hemodialysis on day 14 after having introduced combined cytostatic treatment. Comparing the data of a subgroup of 12 patients receiving rasburicase with that of a historic cohort of 14 patients treated with allopurinol indicated the superiority of rasburicase over allopurinol in prophylaxis and treatment of hyperuricemia in children with leukemia and lymphoma.