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

Resource-adapted strategies in the management of paediatric Burkitt lymphoma in low- and middle-income country setting and outcomes: An Indian centre experience

Burkitt lymphoma (BL) is a challenging cancer to treat in resource-limited settings. We retrospectively analysed 85 BL children ≤14 years, treated during 2007-2017. Median age was 6.5 (2-12) years. Group A, B and C disease was seen in 22%, 48% and 30% respectively. Advanced disease was seen in 78% (stage III 33, stage IV 25). Six children had stage I and 21 had stage II disease. The commonest primary site was the abdomen (56%). Ten children had central nervous system (CNS) and 22 had marrow involvement. Treatment protocols included cyclophosphamide, oncovin, methotrexate, prednisolone (COMP) (United Kingdom Childhood Cancer Study Group) for group A and Multi Centre Protocol 842 (MCP 842) (2007-2008)/modified Lymphomes Malins de Burkitt (LMB) 96 (2009-2017) for group B and C disease. Seventeen children developed tumour lysis syndrome (TLS). Twenty-two children (25%) expired, six from TLS, four from infection and 12 due to disease. Median follow-up was 8.6 (4-15) years. Four-year event-free survival (EFS) and overall survival (OS) were 72.9% and 74.1% respectively. Four-year OS for group A, B, C and stage I, II, III, IV was 100%, 73.2%, 56% (p = 0.005) and 100%, 90.5%, 72.7%, 56% (p = 0.02) respectively. Advanced disease and TLS were significant predictors of inferior EFS on multivariate analysis. We could achieve reasonably good survival in resource-limited settings with judicious use of resources like single-dose rasburicase and modified dose methotrexate.

The Potential of Leucomethylene Blue in Methemoglobinemia Treatment: A New Hope for Patients with G6PD?

Methylene blue (MB) has been routinely used to treat methemoglobinemia. In the body, MB is reduced to leucomethylene blue (LMB) by NADPH-dependent methemoglobin (MetHB) reductase, and then LMB reduces Fe3+ to Fe2+. In glucose-6-phosphate dehydrogenase (G6PD) deficiency, NADPH is not produced sufficiently to protect erythrocytes against oxidative stress and to take part in relevant biochemical reactions. Since MB is an oxidative agent, its administration in individuals with G6PD deficiency leads to an increased risk of hemolysis through oxidative stress and even death. Therefore, its administration has been prohibited from treating methemoglobinemia in G6PD patients. As an antioxidant and direct reducing agent for Fe3+, LMB may be prescribed for treating MetHB in patients with G6PD deficiency. Considering the biochemical process of turning MB into LBM and the reducing nature of LMB, it seems LMB is a safer drug than MB in treating methemoglobinemia. LMB can even be administrated in other treatments without any concern about increasing oxidative stress, exacerbating the inflammation. Proof-ofconcept experimental and clinical trials could substantiate this hypothesis.

Tumour lysis syndrome

Tumour lysis syndrome (TLS) represents a critical oncological emergency characterized by extensive tumour cell breakdown, leading to the swift release of intracellular contents into the systemic circulation, outpacing homeostatic mechanisms. This process results in hyperuricaemia (a by-product of intracellular DNA release), hyperkalaemia, hyperphosphataemia, hypocalcaemia and the accumulation of xanthine. These electrolyte and metabolic imbalances pose a significant risk of acute kidney injury, cardiac arrhythmias, seizures, multiorgan failure and, rarely, death. While TLS can occur spontaneously, it usually arises shortly after the initiation of effective treatment, particularly in patients with a large cancer cell mass (defined as ≥500 g or ≥300 g/m2 of body surface area in children). To prevent TLS, close monitoring and hydration to improve renal perfusion and urine output and to minimize uric acid or calcium phosphate precipitation in renal tubules are essential. Intervention is based on the risk of a patient of having TLS and can include rasburicase and allopurinol. Xanthine, typically enzymatically converted to uric acid, can accumulate when xanthine oxidases, such as allopurinol, are administered during TLS management. Whether measurement of xanthine is clinically useful to optimize the use of allopurinol or rasburicase remains to be determined.

[Electrolyte disorders in oncological patients]

Electrolyte disorders (ED) are common in patients with cancer and in most cases, the etiologies do not differ from the general population. They may also be induced by the cancer, its therapy or paraneoplastic syndromes. ED are associated with poor outcomes, increased morbidity and mortality in this population. Hyponatremia is the most common disorder, often multifactorial, iatrogenic or secondary to the syndrome of inappropriate antidiuretic hormone secretion, usually due to small cell lung cancer. More rarely, hyponatremia may reveal adrenal insufficiency. Hypokalemia is generally multifactorial and associated with other ED. Cisplatin and ifosfamide induce proximal tubulopathies with hypokalemia and/or hypophosphatemia. Hypomagnesemia is often iatrogenic, related to cisplatin or cetuximab, but can be prevented by supplementation. Hypercalcemia can impair life quality and be life-threatening in the most severe cases. Hypocalcemia is less common and often of iatrogenic origin. Finally, the tumor lysis syndrome is a diagnostic and therapeutic emergency that affects the prognosis of patients. Its incidence tends to increase in solid oncology, related to the improvement of therapies. Prevention and early diagnosis of ED are essential to optimize the overall management of patients with underlying cancer and cancer therapy. The aim of this review is to synthesize most frequent ED and their management.

A retrospective review of rasburicase utilization in pediatric and adult patients across a large health system

PURPOSE

This study aimed to characterize rasburicase dosing and duration. Secondary objectives included characterizing the indication of rasburicase and identifying the utilization of prophylactic therapy for tumor lysis syndrome (TLS).

METHODS

This retrospective review included patients 0 to 89 years old admitted between 1 January 2021 and 31 December 2021, and received at least one dose of rasburicase. Patients were excluded if they were >89 years old, pregnant, lactating, or received rasburicase outpatient.

RESULTS

A total of 192 patients, 176 adults and 16 pediatric patients were included in the retrospective review. Of the total population, 184 received a fixed dose of rasburicase and 8 patients received a weight-based dose (0.15 mg/kg/dose) of rasburicase. The average dose administered was 3.4 mg for fixed and 2.99 mg for weight-based dosing. Nearly half (49.5%) the patients received rasburicase for an elevated uric acid but did not meet Cairo-Bishop criteria for TLS. Only 42.2% received at least one dose of allopurinol within 5 days prior to rasburicase and 18.8% received aggressive hydration within 72 h prior to rasburicase.

CONCLUSION

The majority of rasburicase administered was ordered as fixed dose for a uric acid level ≥7.5 mg/dL. Most patients did not meet criteria for laboratory or clinical TLS and less than half the patients received prophylactic allopurinol and/or aggressive hydration. These study results are supported by recent literature for fixed dose rasburicase as a safe and economical dosing strategy compared to weight-based dosing.

Synthetically mannosylated antigens induce antigen-specific humoral tolerance and reduce anti-drug antibody responses to immunogenic biologics

Immunogenic biologics trigger an anti-drug antibody (ADA) response in patients that reduces efficacy and increases adverse reactions. Our laboratory has shown that targeting protein antigen to the liver microenvironment can reduce antigen-specific T cell responses; herein, we present a strategy to increase delivery of otherwise immunogenic biologics to the liver via conjugation to a synthetic mannose polymer, p(Man). This delivery leads to reduced antigen-specific T follicular helper cell and B cell responses resulting in diminished ADA production, which is maintained throughout subsequent administrations of the native biologic. We find that p(Man)-antigen treatment impairs the ADA response against recombinant uricase, a highly immunogenic biologic, without a dependence on hapten immunodominance or control by T regulatory cells. We identify increased T cell receptor signaling and increased apoptosis and exhaustion in T cells as effects of p(Man)-antigen treatment via transcriptomic analyses. This modular platform may enhance tolerance to biologics, enabling long-term solutions for an ever-increasing healthcare problem.

Synthetically mannosylated antigens induce antigen-specific humoral tolerance and reduce anti-drug antibody responses to immunogenic biologics

Immunogenic biologics trigger an anti-drug antibody (ADA) response in patients, which reduces efficacy and increases adverse reactions. Our laboratory has previously shown that targeting protein antigen to the liver microenvironment can reduce antigen-specific T cell responses; herein, we present a strategy to increase delivery of otherwise immunogenic biologics to the liver via conjugation to a synthetic mannose polymer (p(Man)). This delivery leads to reduced antigen-specific T follicular helper cell and B cell responses resulting in diminished ADA production, which is maintained throughout subsequent administrations of the native biologic. We found that p(Man)-antigen treatment impairs the ADA response against recombinant uricase, a highly immunogenic biologic, without a dependence on hapten immunodominance or control by Tregs. We identify increased TCR signaling and increased apoptosis and exhaustion in T cells as effects of p(Man)-antigen treatment via transcriptomic analyses. This modular platform may enhance tolerance to biologics, enabling long-term solutions for an ever-increasing healthcare problem.

Rescue Therapies for AKI in Onconephrology: Rasburicase and Glucarpidase

Tumor lysis syndrome (TLS) and high-dose methotrexate (HD MTX) toxicity can present with potentially severe complications, including acute kidney injury, in patients with malignancy. Guidelines for using rasburicase and glucarpidase as rescue therapies for TLS and HD MTX toxicity, respectively, are widely used by clinicians intending to mitigate organ toxicity and decrease morbidity and mortality as a consequence of cancer therapy. This review discusses the pathogenesis of TLS and HD MTX-associated toxicity, to understand the mechanism of action of these therapeutic agents and to review the currently available evidence supporting their use.

A phase II study to evaluate the efficacy of low-dose rasburicase (1.5mg) in adolescent and adult acute leukemia and high-grade lymphomas with tumor lysis syndrome

The FDA recommended dose of rasburicase 0.2 mg/kg/day till the resolution of TLS or up to 5 days, might be in excess and is prohibitively expensive. The quality of evidence supporting low dose rasburicase is limited. The objective is to study the plasma uric acid response rate. This is a single center, non-randomised phase II study. Duration is 10 June 2017 till 30 July 2019. Study setting is at Adult Hematolymphoid Unit, Tata Memorial Center. Participants are patients with acute leukemia and high-grade lymphomas aged >/=18 years, with ECOG PS of 0-3, with either laboratory or clinical TLS. Rasburicase was administered at fixed-dose of 1.5 mg. The subsequent doses (1.5 mg each dose) were administered only if plasma UA levels did not decline by >50% on day 2, at the physician's discretion. We demonstrate that a low-dose rasburicase strategy leads to rapid and sustained reductions of uric acid in about 52% patients.

Supportive care in pediatric acute myeloid leukemia:Expert-based recommendations of the NOPHO-DB-SHIP consortium

INTRODUCTION

Pediatric acute myeloid leukemia (AML) is the second most common type of pediatric leukemia. Patients with AML are at high risk for several complications such as infections, typhlitis, and acute and long-term cardiotoxicity. Despite this knowledge, there are no definite supportive care guidelines as to what the best approach is to manage or prevent these complications.

AREA COVERED

The NOPHO-DB-SHIP (Nordic-Dutch-Belgian-Spain-Hong-Kong-Israel-Portugal) consortium, in preparation for a new trial in pediatric AML patients, had dedicated meetings for supportive care. In this review, the authors discuss the available data and outline recommendations for the management of children and adolescents with AML with an emphasis on hyperleukocytosis, tumor lysis syndrome, coagulation abnormalities and bleeding, infection, typhlitis, malnutrition, cardiotoxicity, and fertility preservation.

EXPERT OPINION

Improved supportive care has significantly contributed to increased cure rates. Recommendations on supportive care are an essential part of treatment for this highly susceptible population and will further improve their outcome.

Tumor Lysis Syndrome: An Endless Challenge in Onco-Nephrology

Tumor lysis syndrome (TLS) is a common cause of acute kidney injury in patients with malignancies, and it is a frequent condition for which the nephrologist is consulted in the case of the hospitalized oncological patient. Recognizing the patients at risk of developing TLS is essential, and so is the prophylactic treatment. The initiation of treatment for TLS is a medical emergency that must be addressed in a multidisciplinary team (oncologist, nephrologist, critical care physician) in order to reduce the risk of death and that of chronic renal impairment. TLS can occur spontaneously in the case of high tumor burden or may be caused by the initiation of highly efficient anti-tumor therapies, such as chemotherapy, radiation therapy, dexamethasone, monoclonal antibodies, CAR-T therapy, or hematopoietic stem cell transplantation. It is caused by lysis of tumor cells and the release of cellular components in the circulation, resulting in electrolytes and metabolic disturbances that can lead to organ dysfunction and even death. The aim of this paper is to review the scientific data on the updated definition of TLS, epidemiology, pathogenesis, and recognition of patients at risk of developing TLS, as well as to point out the recent advances in TLS treatment.

The efficacy and cost-impact of rasburicase 3 mg versus 6 mg for the management of tumor lysis syndrome: A multicenter analysis

Purpose: Hyperuricemia is a complication arising from tumor lysis syndrome (TLS). Literature has shown that a single 3 mg dose was just as efficacious as a single 6 mg dose when the uric acid (UA) levels were ≤12 mg/dL. Here, we present a multi-center analysis rasburicase utilization and its effect on healthcare costs. Methods: This is a multi-center, retrospective analysis of adult cancer patients who were admitted to Methodist Le Bonheur Healthcare hospitals and received rasburicase from February 2020 to February 2021. The primary endpoint was to test whether rasburicase 3 mg had similar rates of uric acid normalization (defined as uric acid ≤7.5 mg/dL) within 24 h as a dose of 6 mg. Results: Seventy-nine patients were included in the study. While the baseline uric acid was lower in the 3 mg arm compared to the 6 mg arms, there was no difference in the uric acid normalization at 24 h between the 3 mg arm (95%) and 6 mg arm (82%) (p = 0.134). A cost-savings of over $300,000 annually can be achieved with the proposed protocol. Conclusion: A single, fixed rasburicase dose of 3 mg was effective in normalizing uric acid levels within 24 h, and is associated with significant cost-savings.

Tumor Lysis Syndrome

Tumor lysis syndrome (TLS) is an oncologic emergency due to massive tumor cell lysis with the release of large amounts of potassium, phosphate, and nucleic acids into the systemic circulation. Clinical presentation is characterized by hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia. Acute kidney injury due to tumor lysis is potentiated by the precipitation of uric acid and calcium phosphate as well as renal vasoconstriction. Early recognition of tumor lysis can help prevent cardiac arrhythmias, seizures, and death. Management includes intravenous hydration to maintain urine flow, medications targeting hyperuricemia including rasburicase and allopurinol and in severe cases renal replacement therapy may be required.

Single-Dose Rasburicase Might Be Adequate To Overcome Tumor Lysis Syndrome In Hematological Malignancies

INTRODUCTION

Tumor lysis syndrome (TLS) is a commonly observed oncological emergency that requires prompt diagnosis and treatment. Rasburicase is a recombinant urate oxidase endorsed in TLS for the treatment of hyperuricemia. The effect of single-dose 7.5 mg rasburicase at longer follow-ups was not widely investigated.

PATIENTS AND METHODS

Eighty-two patients included in the study with clinical TLS and laboratory TLS. The primary endpoint was the normalization of uric acid (<6mg/dL) within 24 hours of rasburicase administration, which was described as treatment success. The secondary endpoint was defined as having sustained response at the first week. The third endpoint was defined as the reaching the baseline renal function before TLS.

RESULTS

We found that the use of a 7.5 mg dose of rasburicase controlled uric acid in 74 of 82 (90,2%) patients at the 24th hour. In the first week, uric acid remained at normal levels in 69 of 82 (84,1%) patients. At 24 hours, the TLS risk group was the only predictor for failing uric acid normalization; at the end of the first week, no predictive factor was identified for failing uric acid normalization.

CONCLUSION

Rasburicase at 7.5 mg dose is an important agent for controlling laboratory and clinical TLS at 24 hours and extending its effect to the first week.

A phase 2 trial of single low doses of rasburicase for treatment of hyperuricemia in adult patients with acute leukemia

BACKGROUND

Rasburicase can markedly and rapidly decrease uric acid (UA) levels, thereby preventing and treating tumor lysis syndrome. However, rasburicase is expensive, especially when used as per the manufacturer's recommended dosage of 0.2 mg/kg/day for up to 5 days. Numerous reports have shown that lower, and even single doses are effective in lowering UA levels but prospective randomized studies comparing low doses have not been performed.

OBJECTIVES

To prospectively determine the efficacy and safety of two single low doses of rasburicase in adult patients (pts) with acute leukemia and elevated plasma UA.

METHODS

Eligible pts aged ≥ 18 years old with acute leukemia and UA ≥ 7.5 mg/dL were randomized to receive an initial single dose of rasburicase 1.5 mg (Arm A) or 3 mg (Arm B) on day 1 in an unblinded fashion. All pts received allopurinol 300 mg daily on days 1-6.

RESULTS

Twenty-four pts (median age 69 years; 14 males and 10 females) were enrolled in this phase 2 study (12 on each arm). Twenty pts had acute myeloid leukemia while 3 had acute lymphoblastic leukemia, and 1 had acute promyelocytic leukemia. Median initial UA level was 9.8 mg/dL. Eighty-three percent of pts in both arms achieved UA < 7.5 mg/dL by 24 h after therapy. Five pts (21 %; 2 from Arm A and 3 from Arm B) required additional doses of rasburicase. The majority (23/24) of pts achieved UA goals after 1-2 doses of rasburicase. None had worsening renal function. Both doses were well tolerated, and no treatment related adverse events were reported.

CONCLUSIONS

Single doses of rasburicase (as low as 1.5-3 mg) used in addition to allopurinol were well tolerated and highly efficacious (83 % response rate) in decreasing UA levels within 24 h of administration in adult acute leukemia pts with hyperuricemia.

Efficacy of Single Low-Dose Rasburicase in Management of Tumor Lysis Syndrome in Leukemia and Lymphoma Patients

BACKGROUND

Tumor lysis syndrome (TLS) is a metabolic emergency in hematology patients. The recommended dose of rasburicase for the management of TLS is 0.2 mg/kg per day for 5 days, which is cost prohibitive for many patients. We sought to determine the efficacy of single low-dose rasburicase in the prevention and treatment of hyperuricemia in TLS.

PATIENTS AND METHODS

We planned a prospective study for the safety and efficacy of fixed (weight based) dose of rasburicase to manage TLS. Patients diagnosed with leukemia/lymphoma with laboratory or clinically confirmed TLS or presence of ≥ 2 high-risk factors and serum uric acid > 7.5 mg/dL were included. The primary endpoint was uric acid normalization (< 7.5 mg/dL) within 24 hours of rasburicase administration.

RESULTS

Fifty-five patients were recruited for this study. Pediatric patients (< 18 years) accounted for 43.6% of cases. Rasburicase was provided prophylactically to 43 patients (78.2%) and for treating TLS to 12 (21.8%). Mean ± standard deviation serum uric acid at baseline and 24 hours was 9.2 ± 1.8 mg/dL and 3.2 ± 2.1 mg/dL, respectively. There was significant reduction in the serum uric acid and creatinine (P < .001) within 24 hours of rasburicase administration. The response was maintained up to 72 hours. A single dose of rasburicase was effective in 94.5% of patients. Single low-dose rasburicase led to 95% direct cost savings compared to the recommended dose.

CONCLUSION

Single-dose rasburicase with frequent laboratory monitoring is effective in the management of TLS and offers significant cost reductions.

KDIGO Controversies Conference on onco-nephrology: kidney disease in hematological malignancies and the burden of cancer after kidney transplantation

The bidirectional relationship between cancer and chronic kidney disease (CKD) is complex. Patients with cancer, particularly those with hematological malignancies such as multiple myeloma and lymphoma, are at increased risk of developing acute kidney injury and CKD. On the other hand, emerging evidence from large observational registry analyses have consistently shown that cancer risk is increased by at least 2- to 3-fold in kidney transplant recipients, and the observed increased risk occurs not only in those who have received kidney transplants but also in those on dialysis and with mild- to moderate-stage CKD. The interactions between cancer and CKD have raised major therapeutic and clinical challenges in the management of these patients. Given the magnitude of the problem and uncertainties, and current controversies within the existing evidence, Kidney Disease: Improving Global Outcomes (KDIGO) assembled a global panel of multidisciplinary clinical and scientific expertise for a controversies conference on onco-nephrology to identify key management issues in nephrology relevant to patients with malignancy. This report covers the discussed controversies in kidney disease in hematological malignancies, as well as cancer after kidney transplantation. An overview of future research priorities is also discussed.

Prevention and Treatment of Tumor Lysis Syndrome in the Era of Onco-Nephrology Progress

Background: Tumor lysis syndrome (TLS) is an oncologic emergency due to a rapid break down of malignant cells usually induced by cytotoxic therapy, with hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and serious clinical consequences such as acute renal injury, cardiac arrhythmia, hypotension, and death. Rapidly expanding knowledge of cancer immune evasion mechanisms and host-tumor interactions has significantly changed our therapeutic strategies in hemato-oncology what resulted in the expanding spectrum of neoplasms with a risk of TLS. Summary: Since clinical TLS is a life-threatening condition, identifying patients with risk factors for TLS development and implementation of adequate preventive measures remains the most critical component of its medical management. In general, these consist of vigilant laboratory and clinical monitoring, vigorous IV hydration, urate-lowering therapy, avoidance of exogenous potassium, use of phosphate binders, and – in high-risk cases – considering cytoreduction before the start of the aggressive agent or a gradual escalation of its dose. Key Messages: In patients with a high risk of TLS, cytotoxic chemotherapy should be given in the facility with ready access to dialysis and a treatment plan discussed with the nephrology team. In the case of hyperkalemia, severe hyperphosphatemia or acidosis, and fluid overload unresponsive to diuretic therapy, the early renal replacement therapy (RRT) should be considered. One must remember that in TLS, the threshold for RRT initiation may be lower than in other clinical situations since the process of cell breakdown is ongoing, and rapid increases in serum electrolytes cannot be predicted.

Evaluation of the safety and efficacy of low-dose rasburicase in critically ill children with haematological malignancies

Background The recommended dose of rasburicase is quite expensive, thus limiting its use. Whether a lower dose of rasburicase would be equally effective for critically ill children, who often have more complicated situations and a higher risk of hospital death, is still unknown. Objective To explore the safety and efficacy of low-dose rasburicase in critically ill children with haematological malignancies who are at high risk of tumour lysis syndrome. Setting A single-centre retrospective cohort study. Method Children with haematological malignancies who had a history of rasburicase exposure during an intensive care unit stay were enrolled. Patients were divided into two groups according to the initial dosage of rasburicase: the standard-dose group (> 0.1 mg/kg/day) and the low-dose group (≤ 0.1 mg/kg/day). The adverse events and short-term prognosis of the two groups were compared. Results Thirty-seven children were selected, 22 in the standard-dose group and 15 in the low-dose group. The most common tumour type was Burkitt's lymphoma (81%), followed by acute lymphoblastic leukaemia (11%). All patients were at high risk of tumour lysis syndrome, and 73% of them had 3 or more tumour lysis syndrome risk factors. The uric acid levels of 90% of patients with hyperuricaemia returned to the normal range within 12 h (100% in the standard-dose group and 75% in the low-dose group, P = 0.083). Eighty-four percent of patients presented serious complications, including tumour lysis syndrome (73%), acute kidney injury (59%), renal replacement treatment (24%), respiratory failure (24%), disseminated intravascular coagulation (16%) and heart failure (11%). There was no significant difference in the incidence of serious complications between the two groups. The overall 7-day and 28-day survival rates after intensive care unit admission were 86% and 84%, respectively. The average length of stay in the intensive care unit was 9.92 ± 5.13 days. Neither the short-term mortality nor the length of stay in the intensive care unit were significantly different between the two groups. Conclusion Low-dose rasburicase is effective and may be an acceptable choice for critically ill children with haematological malignancies.

Clinical Interventions to Prevent Tumour Lysis Syndrome in Hematologic Malignancy: A Multisite Retrospective Chart Review

BACKGROUND

Tumour lysis syndrome (TLS) occurs when lysis of malignant cells causes electrolyte disturbances and potentially organ dysfunction. Guidelines recommending preventive therapy according to TLS risk are based on low-quality evidence.

OBJECTIVES

The primary objective was to characterize utilization of TLS preventive strategies through comprehensive description of current practice. Secondary objectives were to determine TLS incidence, to compare use of preventive strategies among intermediate- and high-risk patients, and to describe TLS treatment strategies.

METHODS

This retrospective chart review examined data for patients with newly diagnosed hematologic malignancy who were admitted to an oncology centre and/or affiliated intensive care unit between October 2015 and September 2016 in Toronto, Ontario, Canada.

RESULTS

Fifty-eight patients (29 at intermediate risk, 29 at high risk) were eligible for inclusion. Use of preventive allopurinol, IV bicarbonate, and furosemide was similar between groups. Rasburicase was more frequently used for high-risk patients (3% [1/29] of intermediate-risk patients versus 36% [9/25] of high-risk patients; p = 0.003). In 4 (14%) of the intermediate-risk patients and 2 (8%) of the high-risk patients, TLS developed during the admission. TLS was observed in 10% (1/10) of patients who received preventive rasburicase and 11% (5/44) of those who did not (p > 0.99), and in 9% (4/45) of patients who received preventive IV bicarbonate and 25% (2/8) of those who did not (p = 0.22). Treatment strategies included rasburicase, IV bicarbonate, furosemide, and renal replacement therapy.

CONCLUSIONS

In this retrospective chart review, rasburicase was more commonly used for high-risk patients, whereas the use of other agents was similar between risk groups. This pattern of use is inconsistent with guidelines, which recommend that all high-risk patients receive rasburicase. There was no difference in TLS incidence between patients who did and did not receive preventive rasburicase or IV bicarbonate. Further prospective studies are needed to inform management of patients with malignancies who are at intermediate or high risk of TLS.

Acute kidney injury in the patient with cancer

Dramatic advances in the care of patients with cancer have led to significant improvement in outcomes and survival. However, renal manifestations of the underlying cancer as well as the effects of anti-neoplastic therapies leave patients with significant morbidity and chronic kidney disease risks. The most common renal manifestations associated with cancer include acute kidney injury (AKI) in the setting of multiple myeloma, tumor lysis syndrome, post-hematopoietic stem cell therapy, and AKI associated with chemotherapy. Knowledge of specific risk factors, modification of risk and careful attention to rapid AKI diagnosis are critical for improving outcomes.

Rasburicase versus intravenous allopurinol for non-malignancy-associated acute hyperuricemia in paediatric cardiology patients

OBJECTIVES

Limited data exist for management of hyperuricemia in non-oncologic patients, particularly in paediatric cardiac patients. Hyperuricemia is a risk factor for acute kidney injury and may prompt treatment in critically ill patients. The primary objective was to determine if rasburicase use was associated with greater probability normalisation of serum uric acid compared to allopurinol. Secondary outcomes included percent reduction in uric acid, changes in serum creatinine, and cost of therapy.

DESIGN

A single-centre retrospective chart review.

SETTING

A 20-bed quaternary cardiovascular ICU in a university-based paediatric hospital in California.

PATIENTS

Patients admitted to cardiovascular ICU who received rasburicase or intravenous allopurinol between 2015 and 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data from a cohort of 14 patients receiving rasburicase were compared to 7 patients receiving IV allopurinol. Patients who were administered rasburicase for hyperuricemia were more likely to have a post-treatment uric acid level less than 8 mg/dl as compared to IV allopurinol (100 versus 43%; p = 0.0058). Patients who received rasburicase had a greater absolute reduction in post-treatment day 1 uric acid (-9 mg/dl versus -1.9 mg/dl; p = 0.002). There were no differences in post-treatment day 3 or day 7 serum creatinine or time to normalisation of serum creatinine. The cost of therapy normalised to a 20 kg patient was greater in the allopurinol group ($18,720 versus $1928; p = 0.001).

CONCLUSION

In a limited paediatric cardiac cohort, the use of rasburicase was associated with a greater reduction in uric acid levels and associated with a lower cost compared to IV allopurinol.

Evaluation of Rasburicase Use in the Fraser Health Authority: A Retrospective Review

BACKGROUND

Rasburicase, a recombinant urate oxidase, is restricted in the Fraser Health Authority (FHA) to the "treatment of acute or at high risk of tumour lysis syndrome [TLS], when other therapeutic options are not suitable". The manufacturer's recommended dosage is 0.2 mg/kg daily for up to 7 days. Given the high cost of this drug, several studies have investigated other strategies and found that a single dose, repeated as needed, is effective in reducing serum uric acid. However, there are currently no guidelines in FHA for the use of rasburicase, which may result in different prescribing practices within the health authority.

OBJECTIVES

To describe the prescribing of rasburicase in FHA, including indications and doses, and to report the uric acid-lowering effects of rasburicase and any clinical outcomes, such as dialysis or death.

METHODS

This retrospective descriptive chart review included adult patients receiving care in FHA for whom rasburicase was prescribed between June 1, 2010, and November 30, 2016. Descriptive statistics were used to summarize patient characteristics and results.

RESULTS

The prescribing practices for rasburicase in this health authority were largely inconsistent, but the most common dose administered was 3 mg (8/12 [67%] among those receiving rasburicase for prophylaxis and 9/32 [28%] among those receiving rasburicase for treatment; combined total 17/44 or 39%). Regardless of dose, rasburicase reduced serum uric acid levels to less than 476 μmol/L and decreased the risk of TLS.

CONCLUSIONS

Having a uniform approach-involving a single dose that can be repeated as needed-for prevention and treatment of elevated serum uric acid levels could result in sufficient reduction of uric acid levels with fewer doses and lower cost. The results of this study support the need for a resource in FHA to guide and standardize the use of rasburicase.

Impact of early rasburicase on incidence of clinical tumor lysis syndrome in lymphoma

Early administration of rasburicase to enhance uric acid (UA) elimination has been adopted without robust evidence in support of its impact on clinical outcomes in tumor lysis syndrome (TLS), specifically, the prevention of acute kidney injury (AKI). This was a retrospective cohort study of adult lymphoma patients at intermediate or high risk for TLS. Excluded patients had AKI or were on dialysis at hospital admission. The incidence of new AKI in the setting of TLS was described along with predictors of its development, including early rasburicase use. In 383 included patients, the incidence of new-onset AKI during hospitalization was 6%. Predictors included age, history of renal or cardiovascular disease, and UA >8 mg/dL. Rasburicase use did not significantly impact the risk of developing AKI (HR 2.3; p = .11). The UA level at the time of administration did not modify the effect of rasburicase on prevention of AKI (p = .36 for the interaction term).

Update on the prevention and treatment of tumor lysis syndrome

Tumor lysis syndrome is a constellation of metabolic derangements seen when tumor cells die and release their intracellular contents into the systemic circulation. Hyperkalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia may lead to severe organ dysfunction and even death. Tumor lysis syndrome is classically considered a complication of successful cancer treatment, but it can also occur in untreated malignancies characterized by rapid proliferation. In this review, we cover the types of cancers and chemo- and immunotherapies associated with tumor lysis syndrome, the mechanisms by which severe metabolic derangements can develop, and the available treatments.

Risk-based management strategy and outcomes of tumor lysis syndrome in children with leukemia/lymphoma: Analysis from a resource-limited setting

BACKGROUND

Data from low- and middle-income countries on tumor lysis syndrome (TLS) in the pediatric population are limited. This study aims to analyze the clinical and biochemical characteristics and treatment outcomes of TLS in children with leukemia/lymphomas in a resource-limited setting.

PROCEDURE

Children with intermediate risk (IRD) and high risk (HRD) for developing TLS were retrospectively studied at a tertiary cancer center in India.

RESULTS

Over a three-year period, 224 children with acute leukemia/lymphoma having IRD (21.8%, n = 49) and HRD (78.1%, n = 175) were identified. TLS developed in 53.6% (n = 120) cases, of which 75% (n = 90) had laboratory TLS alone. Thirteen children had clinical TLS (C-TLS) at presentation while 17 patients progressed to develop C-TLS. TLS developed in 51% (n = 25) and 54.5% (n = 95) of children with IRD and HRD, respectively. Rasburicase was used in 8.5% (n = 19) cases and five children required hemodialysis. Two children (0.8%) expired during the course of TLS management. Multivariate analysis identified the presence of hyperuricemia as the single significant risk factor for developing TLS. When children in whom a 25% change in biochemical values from the baseline that falls within the normal range were excluded, 21.4% (48/224) cases were identified to have clinically relevant TLS (8% in IRD and 25% in HRD).

CONCLUSION

With hydration, supportive care and judicious use of rasburicase, it is feasible to manage TLS efficiently in resource-limited settings. A modification of the TLS definition criteria would help to identify clinically relevant TLS.

Single 6-mg dose of rasburicase: The experience in a large academic medical center

Background

Tumor lysis syndrome is an oncologic emergency due to the release of tumor cell contents, leading to metabolic derangements. Rasburicase, a recombinant urate oxidase, catabolizes uric acid. At our institution, we administer a single 6-mg dose of rasburicase to patients who are at risk for tumor lysis syndrome. We aimed to assess the efficacy of single 6-mg dose of rasburicase and explore risk factors associated with rasburicase failure.

Methods

We report results in 92 adult patients who had a baseline uric acid greater than 7.5 mg/dL and received a single 6-mg dose of rasburicase for the management of tumor lysis syndrome. Responders were defined as those whose uric acid was less than or equal to 7.5 mg/dL within 24–36 h of rasburicase administration. The primary end point was response based on uric acid level. Secondary end points included response to rasburicase in association with lactate dehydrogenase, serum creatinine, calcium, phosphorus, blood pH, and oncologic diagnosis.

Results

Median age was 65 years and 70% were men. Most patients had leukemia (32%) or lymphoma (40%). Eighty-seven of 92 patients (95%), who received single 6-mg dose of rasburicase, achieved a uric acid less than 7.5 mg/dL within 24–36h of dosing. Body mass index was similar between responders and non-responders: 28.6 kg/m2 vs. 26.6 kg/m2, respectively, p = 0.6. Baseline lactate dehydrogenase levels were similar between the groups: 756 U/L vs. 892 U/L, respectively, p = 0.33. Blood pH values documented within 24 h of first dose of rasburicase were also similar between the two groups (n = 30; 7.33 vs. 7.34 respectively, p = 0.6). However, median baseline uric acid was lower in responders than non-responders: 12.3 mg/dL vs. 17.3 mg/dL, respectively, p = 0.012. Baseline serum creatinine and creatinine clearance were similar between responders and non-responders (2.2 mg/dL vs. 3.95 mg/dL; p = 0.12 and 29 mL/min vs. 16 mL/min; p = 0.11, respectively).

Conclusions

Higher baseline uric acid levels were observed in patients who did not respond to the first rasburicase dose. In our study, uric acid levels normalized in 95% of patients after a single 6-mg dose of rasburicase indicating that a single 6-mg dose of rasburicase may be sufficient to manage tumor lysis syndrome, for most patients.

Acute kidney injury and electrolyte disorders in the critically ill patient with cancer

PURPOSE OF REVIEW

Patients with cancer increasingly make up a significant proportion of patients receiving care in the intensive care unit (ICU). Acute kidney injury and cancer-associated electrolyte disorders are encountered in many of these patients and can significantly impact both short-term and long-term outcomes.

RECENT FINDINGS

Advances in chemotherapeutic regimens as well as in our understanding of cancer-associated kidney disease highlight the need for specialized knowledge of the unique causes and therapies required in this subset of critically ill patients. This is especially the case as targeted cancer therapies may have off-target effects that need to be recognized in a timely manner.

SUMMARY

This review outlines key knowledge areas for critical care physicians and nephrologists caring for patients with cancer and associated kidney issues such as acute kidney injury and electrolyte disorders. Specifically, understanding kidney-specific effects of new chemotherapeutic approaches is outlined, and provides an up-to-date compendium of these effects.

Efficacy of Single Dose Rasburicase (1.5 mg) for Prophylaxis and Management of Laboratory Tumor Lysis Syndrome

Rasburicase is a recombinant urate oxidase enzyme approved for use in tumor lysis syndrome (TLS) and it acts by reducing serum uric acid levels. Using rasburicase at the recommended dose of 0.2 mg/kg/day for 5 days is expensive and it is not known whether this extended schedule is clinically beneficial compared to a single fixed dose of 1.5 mg. The aim of the present study was to evaluate the efficacy of single dose rasburicase 1.5 mg in prevention and management of TLS. Rasburicase is available as single use 1.5 mg vial. At our institution a single dose of rasburicase 1.5 mg irrespective of bodyweight has been used in adults and in children a dose of 0.15 mg/kg (maximum 1.5 mg) has been used since 2012 for prevention and management of TLS and subsequent doses are given based on biochemical response and clinical condition. We retrospectively analysed the case records of patients who had received rasburicase from January 2012 to January 2017. The study included 186 patients with hematological malignancies who received rasburicase. Children accounted for 56.4% (n = 105) patients and males comprised 73% (n = 135). Rasburicase was used prophylactically in 59 (31.7%) patients, for laboratory TLS in 76 patients (40.8%) and for clinical TLS in 51 (27.4%) patients. Single fixed dose rasburicase prevented laboratory/clinical TLS in 87% of the prophylactic group and prevented clinical TLS in 72% of the laboratory TLS group. None of the patients in prophylactic and laboratory TLS group developed clinical TLS. However, majority of the patients with clinical TLS required more than one dose rasburicase. Single dose of 1.5 mg (1 vial) rasburicase is efficient in preventing and managing laboratory TLS and is economically viable in resource constrained settings.

Tumor Lysis Syndrome in Chronic Lymphocytic Leukemia with Novel Targeted Agents

Tumor lysis syndrome (TLS) is an uncommon but potentially life-threatening complication associated with the treatment of some cancers. If left untreated, TLS may result in acute renal failure, cardiac dysrhythmia, neurologic complications, seizures, or death. Tumor lysis syndrome is most commonly observed in patients with hematologic malignancies with a high proliferation rate undergoing treatment with very effective therapies. In chronic lymphocytic leukemia (CLL), historically, TLS has been observed less often, owing to a low proliferation rate and slow response to chemotherapy. New targeted therapies have recently been approved in the treatment of CLL, including the oral kinase inhibitors, idelalisib and ibrutinib, and the B-cell lymphoma-2 protein inhibitor, venetoclax. Several others are also under development, and combination strategies of these agents are being explored. This review examines the diagnosis, prevention, and management of TLS and summarizes the TLS experience in CLL clinical trials with newer targeted agents. Overall, the risk of TLS is small, but the consequences may be fatal; therefore, patients should be monitored carefully. Therapies capable of eliciting rapid response and combination regimens are increasingly being evaluated for treatment of CLL, which may pose a higher risk of TLS. For optimal management, patients at risk for TLS require prophylaxis and close monitoring with appropriate tests and appropriate management to correct laboratory abnormalities, which allows for safe and effective disease control.

IMPLICATIONS FOR PRACTICE

Tumor lysis syndrome (TLS) is a potentially fatal condition observed with hematologic malignancies, caused by release of cellular components in the bloodstream from rapidly dying tumor cells. The frequency and severity of TLS is partly dependent upon the biology of the disease and type of therapy administered. Novel targeted agents highly effective at inducing rapid cell death in chronic lymphocytic leukemia (CLL) may pose a risk for TLS in patients with tumors characterized by rapid growth, high tumor burden, and/or high sensitivity to treatment. In this review, prevention strategies and management of patients with CLL who develop TLS are described.

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. Previous reviews did not find clear evidence of benefit of urate oxidase in children with cancer. This review is the second update of a previously published Cochrane review.

OBJECTIVES

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

SEARCH METHODS

In March 2016 we searched CENTRAL, MEDLINE, Embase, and CINAHL. In addition, we searched the reference lists of all identified relevant papers, trials registers and other databases. We also screened conference proceedings and 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. No new studies were identified in the update. 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 did not evaluate the primary outcome (incidence of clinical TLS). It showed no clear evidence of a difference in mortality (both all-cause mortality (Fisher's exact test P = 0.23) and mortality due to TLS (no deaths in either group)), renal failure (Fisher's exact test P = 0.46), and adverse effects between the treatment and the control groups (Fisher's exact test P = 1.0). The frequency of normalisation of uric acid at four hours (10 out of 10 participants in the treatment group versus zero out of nine participants in the control group, Fisher's exact test P < 0.001) and area under the curve of uric acid at four days (MD -201.00 mg/dLhr, 95% CI -258.05 mg/dLhr to -143.95 mg/dLhr; P < 0.00001) were significantly better in the treatment group.One CCT evaluated the primary outcome; no clear evidence of a difference was identified between the treatment and the control groups (RR 0.77, 95% CI 0.44 to 1.33; P = 0.34). 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); no clear evidence of a difference in all-cause mortality was identified between the groups (RR 0.19, 95% CI 0.01 to 3.42; P = 0.26). 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: MD -3.80 mg/dL, 95% CI -7.37 mg/dL to -0.24 mg/dL; P = 0.04), three days (two CCTs: MD -3.13 mg/dL, 95% CI -6.12 mg/dL to -0.14 mg/dL; P = 0.04), four days (two CCTs: MD -4.60 mg/dL, 95% CI -6.39 mg/dL to -2.81 mg/dL; P < 0.00001), and seven days (one CCT: MD -1.74 mg/dL, 95% CI -3.01 mg/dL to -0.47 mg/dL; P = 0.007) after therapy, but not one day (three CCTs: MD -3.00 mg/dL, 95% CI -7.61 mg/dL to 1.60 mg/dL; P = 0.2), five days (one CCT: MD -1.02 mg/dL, 95% CI -2.24 mg/dL to 0.20 mg/dL; P = 0.1), and 12 days (one CCT: MD -0.80 mg/dL, 95% CI -2.51 mg/dL to 0.91 mg/dL; P = 0.36) 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).Another included RCT, with 30 participants, compared different doses of rasburicase (0.2 mg/kg versus 0.15 mg/kg). The primary outcome was not evaluated. No clear evidence of a difference in mortality (all-cause mortality (Fisher's exact test P = 1.0) and mortality due to TLS (no deaths in both groups)) and renal failure (no renal failure in both groups) was identified. It demonstrated no clear evidence of a difference in uric acid normalisation (RR 1.07, 95% CI 0.89 to 1.28; P = 0.49) and uric acid level at four hours (MD 8.10%, 95% CI -0.99% to 17.19%; P = 0.08). Common adverse events of urate oxidase included hypersensitivity, haemolysis, and anaemia, but no clear evidence of a difference between treatment groups was identified (RR 0.54, 95% CI 0.12 to 2.48; P = 0.42).The quality of evidence ranks from very low to low because of imprecise results, and 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 TLS, 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.

Prevention and treatment of tumor lysis syndrome, and the efficacy and role of rasburicase

Tumor lysis syndrome (TLS) is a potentially life-threatening condition that occurs in oncologic and hematologic patients with large tumor burden, either due to cytotoxic therapy or, less commonly, spontaneously because of massive tumor cell lysis. TLS is clinically characterized by acute renal failure, hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. While limited options are available for treating TLS, identifying patients at high risk for developing TLS and prevention in high-risk patients remain an important aspect in the treatment of cancer patients. In general, treatment of TLS consists of intensive hydration, stimulation of diuresis, and, more specifically, in the use of allopurinol and rasburicase. Rasburicase, a recombinant urate oxidase, rapidly and effectively reduces hyperuricemia, which subsequently significantly decreases the risk of acute renal failure and other clinical manifestations of TLS. For this review, a comprehensive literature search using the term “tumor lysis syndrome” and/or “rasburicase” was performed considering articles listed in MEDLINE. Incidence, prevention, and therapy of TLS with a special focus on the role of rasburicase are discussed. We evaluated 120 relevant articles including 35 case reports, 32 clinical trials, and 14 meta-analyses.

Reduced administration of rasburicase for tumor lysis syndrome: A single-institution experience

In the present study, the dosage and duration of rasburicase administration were retrospectively evaluated for the ability to control the serum uric acid (S-UA) level in 13 patients diagnosed with hematological malignancies and tumor lysis syndrome (TLS), or those at risk of developing TLS, at the University of Fukui Hospital. At the time of diagnosis, seven patients already exhibited laboratory TLS, and three demonstrated clinical TLS. All patients received rasburicase in addition to chemotherapy agents. The median dose was 0.19 mg/kg (range, 0.13-0.25 mg/kg), and the median duration was four days (range, 1-7 days). Six patients sequentially received a xanthine oxidase inhibitor, allopurinol or febuxostat. The primary estimate was the normalization of the S-UA level at the end of rasburicase treatment and on treatment day seven. The average S-UA level prior to treatment was 10.4±4.5 mg/dl (mean ±standard deviation), and 11 out of 13 patients demonstrated a S-UA level >7 mg/dl. The S-UA level at the end of rasburicase administration was 0.5±1.5 mg/dl and the S-UA level at day seven was 1.4±1.5 mg/dl. All the patients achieved normalization of the S-UA level. On day seven subsequent to the initiation of treatment, the patients receiving rasburicase for a maximum of three days exhibited an S-UA level of 1.9±1.8 mg/dl, while the patients receiving rasburicase for longer than three days demonstrated an S-UA level of 1.0±1.3 mg/dl (P=0.20; Mann-Whitney test). The administration of 0.13 mg/kg and 0.22 mg/kg resulted in comparable UA level reductions. The administration of allopurinol or febuxostat following rasburicase administration suppressed the re-increase in S-UA level. Therefore, it was concluded that reduced administration of rasburicase successfully controlled the S-UA level in TLS.

How I treat hyperleukocytosis in acute myeloid leukemia

Hyperleukocytosis (HL) per se is a laboratory abnormality, commonly defined by a white blood cell count >100 000/µL, caused by leukemic cell proliferation. Not the high blood count itself, but complications such as leukostasis, tumor lysis syndrome, and disseminated intravascular coagulation put the patient at risk and require therapeutic intervention. The risk of complications is higher in acute than in chronic leukemias, and particularly leukostasis occurs more often in acute myeloid leukemia (AML) for several reasons. Only a small proportion of AML patients present with HL, but these patients have a particularly dismal prognosis because of (1) a higher risk of early death resulting from HL complications; and (2) a higher probability of relapse and death in the long run. Whereas initial high blood counts and high lactate dehydrogenase as an indicator for high proliferation are part of prognostic scores guiding risk-adapted consolidation strategies, HL at initial diagnosis must be considered a hematologic emergency and requires rapid action of the admitting physician in order to prevent early death.

Low-dose rasburicase in hematologic malignancies

OBJECTIVE

To define the efficacy and safety of low-dose rasburicase in children from south India with hematologic malignancies.

METHODS

This study is a retrospective analysis of data on 41 children with hematologic malignacies with laboratory evidence of tumor lysis syndrome (TLS) or clinical features indicating high risk for developing TLS. Patients were treated with rasburicase in doses of 0.1-0.15 mg/kg dose, repeated when necessary.

RESULTS

Male : Female ratio was 32:9. Thirty-six children had laboratory evidence of TLS and 5 were at risk for TLS. Diagnoses were T-cell acute lymphoblastic leukemia (ALL), 19; Pre-B ALL, 17; B-non-Hodgkin lymphoma (NHL), 2; T-NHL, 2; and acute myeloid leukemia (AML), 1. Initial plasma uric acid (PUA): median, 8.5 mg/dl (range, 4.3 to 45.5). Six had creatinine levels of >2 mg/dl on admission; and 10 had peak PO4 levels of >10 mg/dl. Dose of rasburicase used: median, 0.12 mg/kg (range, 0.08-0.24). Median reduction of PUA at 6 h: 80 % (range 40 to 98 %). Twenty-seven needed only one dose; 12 needed 2 or 3 doses; and two needed 5 doses each. One child required dialysis. None of the children developed anaphylaxis or hemolysis and there were no deaths from TLS.

CONCLUSIONS

Low-dose rasburicase (0.1-0.15 mg/kg) is safe and effective in reducing PUA in Indian children with lymphoid malignancies, and thus it may reduce the risk of renal failure from TLS.