A randomized trial of a single-dose rasburicase versus five-daily doses in patients at risk for tumor lysis syndrome

Single dose rasburicase in the management of tumor lysis syndrome in childhood acute lymphoblastic leukemia: A case series

Tumor lysis syndrome (TLS) occurs in malignancies with high proliferative potential and tumor burden, such as lymphomas and leukemias. TLS syndrome is an oncologic emergency, requiring prompt intervention. The metabolic derangements cause acute kidney failure and may lead to cardiac arrhythmias, seizures, and death. With the advent of rasburicase, a recombinant urate oxidase, there has been a decline in the TLS-mediated renal failure and the need for dialysis. The recommended regimen and doses pose a heavy financial burden for patients in developing countries like India. With data and studies proving a similar efficacy for the reduced dose and lesser number of rasburicase, we report here a case series of seven children with acute leukemias, whose TLS was managed by a single dose of rasburicase. A retrospective analysis of case records of seven children with acute lymphoblastic leukemia and TLS, admitted to our Pediatric Oncology Unit of our Hospital between the period 2011 and 2013, was done. All our patients responded to a single dose, indicating that in appropriately monitored patients, single dose followed by as-needed dosing can be cost-saving.

Rasburicase in the management of tumor lysis: an evidence-based review of its place in therapy

Tumor lysis syndrome (TLS) is a potentially life-threatening complication of cancer therapy characterized by two or more of the following laboratory abnormalities: hyperuricemia, hyperkalemia, hypocalcemia, and hyperphosphatemia, with resultant end-organ damage, eg, renal failure, seizures, or cardiac arrhythmias. High-risk patients include those with highly proliferative cancers and/or large tumor burdens, particularly in the setting of highly effective chemotherapy, among other risk factors. Before 2002, antihyperuricemic drug therapy was limited to allopurinol, a xanthine oxidase inhibitor. Rasburicase, a recombinant urate oxidase, was approved by the US Food and Drug Administration for children in 2002 and adults in 2009, ushering in a new era in TLS therapy. We attempted to critically appraise the available evidence supporting the perceived benefits of rasburicase in the management of TLS. A Medline search yielded 98 relevant articles, including 26 retrospective and 22 prospective studies of rasburicase for the treatment of TLS, which were then evaluated to determine the best available evidence for the effectiveness of rasburicase in terms of disease-oriented, patient-oriented, and economic outcomes. Rasburicase is now a standard of care for patients at high risk of TLS despite continuing debate on the correlation between its profound and rapid lowering of plasma uric acid levels with hard patient outcomes, eg, need for renal replacement therapy and mortality. Rasburicase is dramatically effective in lowering plasma uric acid levels. The mortality and cost-effectiveness benefits of this expensive drug remain to be conclusively proven, and well designed, randomized controlled trials are needed to answer these fundamentally important questions.

Urate oxidase for the prevention and treatment of tumour lysis syndrome in children with cancer

BACKGROUND

Tumour lysis syndrome (TLS) is a serious complication of malignancies and can result in renal failure or death. Preliminary reports suggest that urate oxidase is effective in reducing serum uric acid, the build-up of which causes TLS. It is uncertain whether high-quality evidence exists to support its routine use in children with malignancies.

OBJECTIVES

To assess the effects and safety of urate oxidase for the prevention and treatment of TLS in children with malignancies.

SEARCH METHODS

This is an update of the original review. We performed a comprehensive search of the Cochrane Central Register of Controlled Trials (CENTRAL) (in The Cochrane Library issue 1, 2013), MEDLINE (1966 to February 2013), Embase (1980 to February 2013), and CINAHL (1982 to February 2013). In addition, we searched the reference lists of all identified relevant papers. We also explored other internet sources (updated search on 26 February 2013): the NHS' National Research Register, the US National Institutes of Health Ongoing Trials Register, the metaRegister of Controlled Trials, and ProQuest Dissertations & Theses Database. We also screened conference proceedings of the American Society of Clinical Oncology, the European Society for Medical Oncology, and the International Society of Paediatric Oncology meetings from 1993 to 2012. Finally, we contacted experts in the field and the manufacturer of rasburicase, Sanofi-aventis.

SELECTION CRITERIA

Randomised controlled trials (RCT) and controlled clinical trials (CCT) of urate oxidase for the prevention or treatment of TLS in children under 18 years with any malignancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted trial data and assessed individual trial quality. We used risk ratios (RR) for dichotomous data and mean difference (MD) for continuous data.

MAIN RESULTS

We included seven trials, involving 471 participants in the treatment groups and 603 participants in the control groups. One RCT and five CCTs compared urate oxidase and allopurinol. Three trials tested Uricozyme, and three trials tested rasburicase for the prevention of TLS.The RCT showed no significant difference in mortality (both all-cause mortality and mortality due to TLS), renal failure, and adverse effects between the treatment and the control groups. The frequency of normalisation of uric acid at four hours (Fisher's exact test P < 0.001) and area under curve of uric acid at four days (MD -201.00 mg/dLhr, 95% confidence interval (CI) -258.05 mg/dLhr to -143.95 mg/dLhr; P < 0.00001) were significantly better in the treatment group. The trial did not evaluate the primary outcome (incidence of clinical TLS).Pooled results of three CCTs showed significantly lower mortality due to TLS in the treatment group (RR 0.05, 95% CI 0.00 to 0.89; P = 0.04); all-cause mortality was not significantly different between the groups. Pooled results from five CCTs showed significantly lower incidence of renal failure in the treatment group (RR 0.26, 95% CI 0.08 to 0.89; P = 0.03). Results of CCTs also showed significantly lower uric acid in the treatment group at two days (three CCTs), three days (two CCTs), four days (two CCTs), and seven days (one CCT) after therapy, but not one day (three CCTs), five days (one CCT), and 12 days (one CCT) after therapy. Pooled results from three CCTs showed higher frequency of adverse effects in participants who received urate oxidase (RR 9.10, 95% CI 1.29 to 64.00; P = 0.03). One CCT evaluated the primary outcome; no significant difference was identified.Another included RCT, with 30 participants, compared different doses of rasburicase (0.2 mg/kg versus 0.15 mg/kg), which demonstrated no significant difference in uric acid normalisation and uric acid level at four hours). Common adverse events of urate oxidase included hypersensitivity, haemolysis, and anaemia, but no significant difference between treatment groups was identified. No significant difference in mortality (all-cause mortality and mortality due to TLS) and renal failure was identified. The primary outcome was not evaluated.All included trials were highly susceptible to biases.

AUTHORS' CONCLUSIONS

Although urate oxidase might be effective in reducing serum uric acid, it is unclear whether it reduces clinical tumour lysis syndrome, renal failure, or mortality. Adverse effects might be more common for urate oxidase compared with allopurinol. Clinicians should weigh the potential benefits of reducing uric acid and uncertain benefits of preventing mortality or renal failure from TLS against the potential risk of adverse effects.

Controlling serum uric acid using febuxostat in cancer patients at risk of tumor lysis syndrome

Tumor lysis syndrome (TLS) is a life-threatening oncological emergency, in which control of serum uric acid (S-UA) levels is important. S-UA-lowering efficacy of a new xanthine oxidase inhibitor, febuxostat, was retrospectively evaluated in seven patients with hematological malignancies who were at an intermediate risk of developing TLS. A 10-mg dose of febuxostat was initiated and chemotherapy was started within 24 h of administering the first dose of febuxostat. Febuxostat was continued until at least day 7 of chemotherapy treatment. The UA-lowering treatment was considered effective if febuxostat reduced S-UA levels to ≤7.5 mg/dl by day 5. The mean S-UA level at base line was 6.4±2.6 mg/dl and, on day 5, the mean S-UA level was 4.7±1.8 mg/dl. All the patients achieved S-UA levels ≤7.5 mg/dl. Serum creatinine levels decreased from 0.93±0.25 to 0.85±0.25 mg/dl. The estimated glomerular filtration rate values increased from 69.7±24.5 to 76.9±26.2 ml/min. No adverse reactions were noted during the study period and no patients experienced progressive TLS. Successful control of S-UA and improved renal function were obtained in response to febuxostat treatment in cancer patients at a risk of TLS.

Fixed-Dose Rasburicase in Overweight and Obese Patients Versus Normal-Weight Patients

Background: Fixed-dose rasburicase (FDR) is common practice in treating hyperuricemia associated with tumor lysis syndrome in adults; however, there is a lack of data regarding the effectiveness of this dosing strategy specifically in the overweight and obese patient populations. Objective: To determine if patient weight per body mass index (BMI) category is associated with failure of initial FDR as defined by the need for additional dose(s) based on a uric acid level (UAL) ≥7.5 mg/dL within 10 days of previous rasburicase administration. Method: Adults who received FDR per institutional guidelines from October 2008 to August 2013 were reviewed. Patients had either a baseline UAL ≥7.5 mg/dL or were considered high risk (leukemia or lymphoma diagnosis with white blood cell count >50 000/mm3 or lactate dehydrogenase level greater than 2 times the upper limit of normal). Patients were stratified by BMI as underweight (<18.5), normal (18.5-24.9), overweight (25-29.9), or obese (30+). Result: Overall, 12 out of 151 patients who received FDR required a repeat dose of rasburicase. The percentage of patients requiring a repeat rasburicase dose was not different between obese/overweight versus normal/underweight patients (8.7% vs 6.4%, P = 0.75). Similarly, there was no difference between obese alone versus normal/underweight patients (12.3% vs 6.4%; P = 0.51). Conclusion: In this retrospective analysis, patient BMI did not correlate with failure of FDR in adults, suggesting that this dosing strategy is efficacious in the adult population.

Tumor lysis syndrome: new challenges and recent advances

Tumor lysis syndrome (TLS) is an oncologic emergency triggered by the rapid release of intracellular material from lysing malignant cells. Most common in rapidly growing hematologic malignancies, TLS has been reported in virtually every cancer type. Central to its pathogenesis is the rapid accumulation of uric acid derived from the breakdown of nucleic acids, which leads to kidney failure by various mechanisms. Kidney failure then limits the clearance of potassium, phosphorus, and uric acid leading to hyperkalemia, hyperphosphatemia, and secondary hypocalcemia, which can be fatal. Prevention of TLS may be more effective than treatment, and identification of at-risk individuals in whom to target preventative efforts remains a key research area. Herein, we discuss the pathophysiology, epidemiology, and treatment of TLS with an emphasis on the kidney manifestations of the disease.

Rasburicase in tumor lysis syndrome of the adult: a systematic review and meta-analysis

BACKGROUND

The use of rasburicase has been evaluated extensively in children, but not in adults. We review the current literature to evaluate its effect on adults.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & POPULATION

Adults receiving rasburicase for tumor lysis syndrome (TLS).

SELECTION CRITERIA FOR STUDIES

Electronic databases, regulatory documents, and websites were searched up to August 7, 2012. Reference lists of published articles were examined for additional relevant references. Any controlled trial or observational studies (controlled before and after) were included. Studies considering children only or mixing data for children and adults were excluded.

INTERVENTION

Rasburicase for TLS.

OUTCOMES

The primary outcome was TLS development. Secondary outcomes included percentage of patients improving, total adverse events, acute kidney failure, deaths, and serum uric acid and creatinine levels.

RESULTS

21 studies (24 publications) reported data for 1,261 adult patients, 768 receiving rasburicase for either the treatment or prophylaxis of TLS; these comprised 4 controlled trials and 17 observational studies. No statistically significant differences in clinical TLS development were observed in the controlled trials between the rasburicase and control groups. For the observational studies, 7.4% of patients developed clinical TLS after rasburicase (95% CI, 1.7%-16.7%), 93.4% of patients achieved normalized serum uric acid levels after rasburicase treatment (95% CI, 91.7%-94.6%), 4.4% developed acute kidney injury (95% CI, 3.0%-6.0%), and 2.6% died (95% CI, 0.95%-5.0%). The mean reduction in serum uric acid levels ranged from 5.3-12.8 mg/dL, and for serum creatinine levels, from 0.10-2.1 mg/dL.

LIMITATIONS

Controlled trials differed in outcomes reported; meta-analysis was not performed.

CONCLUSIONS

Rasburicase is effective in reducing serum uric acid levels in adults with TLS but at a significant cost, and evidence currently is lacking in adults to report whether rasburicase use improves clinical outcomes compared with other alternatives. Until new evidence is available, use of rasburicase may be limited to adult patients with a high risk of TLS.

Recognizing and managing the expanded risk of tumor lysis syndrome in hematologic and solid malignancies

Tumor lysis syndrome (TLS) is widely recognized as a serious adverse event associated with the cytotoxic therapies primarily used in hematologic cancers, such as Burkitt lymphoma and acute lymphoblastic leukemia. In recent years, TLS has been more widely observed, due at least in part to the availability of more effective cancer treatments. Moreover, TLS is seen with greater frequency in solid tumors, and particularly in bulky tumors with extensive metastases and tumors with organ or bone marrow involvement. The consequences of TLS include the serious morbidity and high risk of mortality associated with the condition itself. Additionally, TLS may delay or force an alteration in the patient’s chemotherapy regimen. The changing patterns of TLS, as well as its frequency, in the clinical setting, result in unnecessarily high rates of illness and/or fatality. Prophylactic measures are widely available for patients at risk of TLS, and are considered highly effective. The present article discusses the various manifestations of TLS, its risk factors and management options to prevent TLS from occurring.

How I treat hematologic emergencies in adults with acute leukemia

Acute myeloid leukemia and acute lymphoblastic leukemia remain devastating diseases. Only approximately 40% of younger and 10% of older adults are long-term survivors. Although curing the leukemia is always the most formidable challenge, complications from the disease itself and its treatment are associated with significant morbidity and mortality. Such complications, discussed herein, include tumor lysis, hyperleukocytosis, cytarabine-induced cellebellar toxicity, acute promyelocytic leukemia differentiation syndrome, thrombohemorrhagic syndrome in acute promyelocytic leukemia, L-asparaginase-associated thrombosis, leukemic meningitis, neutropenic fever, neutropenic enterocolitis, and transfussion-associated GVHD. Whereas clinical trials form the backbone for the management of acute leukemia, emergent clinical situations, predictable or not, are common and do not readily lend themselves to clinical trial evaluation. Furthermore, practice guidelines are often lacking. Not only are prospective trials impractical because of the emergent nature of the issue at hand, but clinicians are often reluctant to randomize such patients. Extensive practical experience is crucial and, even if there is no consensus, management of such emergencies should be guided by an understanding of the underlying pathophysiologic mechanisms.