Efficacy and cost of single-dose rasburicase in prevention and treatment of adult tumour lysis syndrome: a meta-analysis

[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.

Rasburicase dose optimization for tumor lysis syndrome management in a network of community oncology practices

INTRODUCTION

Single, fixed-dose rasburicase administration has been evaluated as an effective strategy in the management of hyperuricemia in the hospital setting, but this has not yet been described within ambulatory community oncology practices. The objective of this study is to evaluate and optimize the dosing strategy for rasburicase in the management of tumor lysis syndrome (TLS)-associated hyperuricemia in The US Oncology Network (The Network).

METHODS

A network-wide guideline was revised to standardize rasburicase dosing from a previous recommended fixed doses of 4.5 or 7.5 mg to either 3 or 6 mg for outpatient rasburicase use in management and prevention of TLS. The primary outcome evaluated mean dose of rasburicase among all patients before and after guideline revision. A retrospective chart review evaluated secondary endpoints.

RESULTS

The primary analysis included 291 patients (128 pre-revised and 163 post-revised guideline implementation). The primary outcome, mean rasburicase dose, was reduced in the post-revision compared to the pre-revision population (mean 6.2 mg pre vs. 4.5 mg post, p < 0.00001) resulting in a reduced cost per rasburicase dose of $974. Fifty patients were included for the secondary analysis. Guideline concordance was identified in 12 (48%) and 16 patients (64%), and uric acid <8 mg/dL post-rasburicase administration occurred in 14 (56%) and 16 patients (64%) before and after guideline revision, respectively.

CONCLUSIONS

Guideline revision and electronic health record modification resulted in a 27% reduction in the mean rasburicase dose and a 50% reduction in repeat rasburicase dosing without a negative impact on clinical efficacy.

Tumor lysis syndrome in induction therapy for acute myeloid leukemia before the rasburicase era

Guidelines recommend rasburicase for high-risk patients to prevent tumor lysis syndrome (TLS). However, little information is available on the incidence and outcome of TLS in AML patients. We analyzed 145 patients with AML who underwent induction therapy before the approval of rasburicase to evaluate the incidence of TLS and the necessity of rasburicase as prophylaxis. Three patients had already developed clinical TLS (CTLS) at diagnosis of AML, and another three developed CTLS after the initiation of chemotherapy. In patients without TLS at diagnosis of AML, the risk for developing TLS was classified as high in 44 patients, intermediate in 41 and low in 57, according to the current guidelines. Allopurinol alone was administered to prevent hyperuricemia in all patients. All three patients who developed CTLS after diagnosis of AML were at high risk of TLS, and had elevated serum creatinine levels and a WBC count greater than 200,000 per microliter at diagnosis of AML. Allopurinol may be insufficient to prevent TLS in high-risk patients with renal dysfunction at diagnosis of AML, especially those with a high tumor burden and a WBC count of 200,000 or more, which indicates that prophylactic administration of rasburicase should be considered.

Rasburicase in treating tumor lysis syndrome: An umbrella review

Tumor lysis syndrome (TLS) remains a debilitating cause of hospitalization and death in patients with cancer and is a significant challenge for healthcare providers despite advancements in its management. This umbrella review analyzed the results of meta-analyses on the use of rasburicase in the treatment of patients with cancer. A literature search was performed of five databases (PubMed, Google Scholar, Cochrane Library, Scopus, Global Index Medicus, and ScienceDirect) for articles with full texts available online. A measurement tool to assess systematic reviews 2 (AMSTAR 2) was used to assess the quality of the included studies, and Review Manager software was used to conduct all statistical analyses. The systematic search identified eight relevant meta-analyses, with primary analyses including outcome data that analyzed mortality, renal failure, and comparisons with allopurinol. The pooled data showed that rasburicase effectively reduced TLS development and serum uric acid levels in children and adults with malignancies. Most outcomes did not differ significantly compared with those of allopurinol. Future trials should focus on the cost-effectiveness of rasburicase compared to that of allopurinol while including high-, intermediate-, and low-risk patients. Rasburicase is safe and effective for managing patients with TLS. However, recent large-scale meta-analyses have reported conflicting results. Most meta-analyses were graded as low to critically low as per AMSTAR 2. The analysis revealed that the benefit of rasburicase did not differ significantly from that of allopurinol, which has higher cost-effectiveness and fewer side effects.

Acute kidney injury following induction of chemotherapy: Diagnosis and management in critical care

A 48-year-old gentleman who had recently commenced chemotherapy for diffuse B-cell lymphoma was admitted to hospital with nausea and generalised weakness. He developed abdominal pain and oliguric acute kidney injury with multiple electrolyte derangements and was transferred to the intensive care unit (ICU). His condition deteriorated, requiring endotracheal intubation and renal replacement therapy (RRT). Tumour lysis syndrome (TLS) is a common and life-threatening complication of chemotherapy and represents an oncological emergency. TLS affects multiple organ systems and is best managed in the ICU with closer monitoring of fluid balance, serum electrolytes, cardiorespiratory and renal function. TLS patients may go on to require mechanical ventilation and RRT. TLS patients require input from a large multidisciplinary team of clinicians and allied health professionals.

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.

Review of Hematological and Oncological Emergencies

Patients with hematological malignancies, both treated and untreated, or solid tumors undergoing treatment are at risk of life-threatening complications, which may present in the emergency department (ED). Such emergencies are diverse in etiology and often require prompt treatment. Traditional complications, such as febrile neutropenia, have had recent guideline updates, which incorporate new evidence and a new validated risk stratification tool. In addition, newer approaches to treatment, such as chimeric antigen receptor (CAR) T-cell therapy, are becoming more widely available and have unique associated toxicities. This review discusses the management of the following hematological and oncological emergencies likely to be encountered in the ED: febrile neutropenia, CAR T-cell toxicities, differentiation syndrome, tumor lysis syndrome, hypercalcemia of malignancy, and hyponatremia.

A retrospective observational study of a low fixed-dose rasburicase protocol for the treatment of tumor lysis syndrome in adults

INTRODUCTION

Tumor lysis syndrome is an oncologic emergency characterized by hyperuricemia. Previous studies have demonstrated that a fixed-dose strategy of rasburicase is as effective as the FDA approved weight-based dose. Albany Medical Center employs rasburicase 1.5 mg in patients with a uric acid (UA) between 8 and 12 mg/dL and 3 mg for UA above12 mg/dL.We aimed to evaluate the UA lowering effectiveness and provider adherence to the institutional protocol, as well as the cost-efficiency of this dosing strategy.

METHODS

This is a single center, retrospective, cohort study. The electronic medical record was used to identify patients receiving rasburicase and to collect baseline demographic and laboratory data. The fixed-dose strategies of rasburicase 1.5 mg and 3 mg were compared in their degree of UA reduction and clinical outcomes. Cost-savings of fixed-dosing was compared to the FDA-approved weight-based dose.

RESULTS

Mean UA reduction in the 1.5 mg group (n = 49) from baseline to 24 hours was 2.88 ± 0.88 mg/dL (p < 0.0001) and 4.83 ± 1.39 mg/dL (p < 0.0001) in the 3 mg group (n = 105). A subgroup analysis of patients who received per protocol initial doses of rasburicase showed a mean reduction in UA from baseline to 24 hours of 2.83 ± 0.62 mg/dL in the 1.5 mg group (n = 42) and 6.12 ± 1.87 mg/dL in the 3 mg group (n = 42). Using a low fixed-dose approach resulted in a cost-savings of $138,077.30 annually.

CONCLUSION

Low fixed-dose rasburicase was an effective treatment, with a dose of 1.5 mg being sufficient to reach a goal UA of less than 8 mg/dL for serum UA levels below 12 mg/dL, while a 3 mg dose is appropriate for levels above 12 mg/dL. Cost analysis indicates this strategy is more cost-efficient than the FDA-approved weight-based dose.

Enzyme Replacement Therapy for Genetic Disorders Associated with Enzyme Deficiency

Mutations in human genes might lead to loss of functional proteins, causing diseases. Among these genetic disorders, a large class is associated with the deficiency in metabolic enzymes, resulting in both an increase in the concentration of substrates and a loss in the metabolites produced by the catalyzed reactions. The identification of therapeutic actions based on small molecules represents a challenge to medicinal chemists because the target is missing. Alternative approaches are biology-based, ranging from gene and stem cell therapy, CRISPR/Cas9 technology, distinct types of RNAs, and enzyme replacement therapy (ERT). This review will focus on the latter approach that since the 1990s has been successfully applied to cure many rare diseases, most of them being lysosomal storage diseases or metabolic diseases. So far, a dozen enzymes have been approved by FDA/EMA for lysosome storage disorders and only a few for metabolic diseases. Enzymes for replacement therapy are mainly produced in mammalian cells and some in plant cells and yeasts and are further processed to obtain active, highly bioavailable, less degradable products. Issues still under investigation for the increase in ERT efficacy are the optimization of enzymes interaction with cell membrane and internalization, the reduction in immunogenicity, and the overcoming of blood-brain barrier limitations when neuronal cells need to be targeted. Overall, ERT has demonstrated its efficacy and safety in the treatment of many genetic rare diseases, both saving newborn lives and improving patients' life quality, and represents a very successful example of targeted biologics.

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.

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.

Assessment of rasburicase utilization for tumor lysis syndrome management in pediatric and adult patients in the inpatient and outpatient settings

INTRODUCTION

At Wake Forest Baptist Health, an adult tumor lysis syndrome pocket card was created in order to optimize management of tumor lysis syndrome and outline specific recommendations for the use of rasburicase. Due to the increased use of rasburicase at our institution and its cost, the purpose of this study was to evaluate the utilization of rasburicase for the management of tumor lysis syndrome in pediatric and adult patients in the inpatient and outpatient settings.

METHODS

This was an observational, single-center, non-randomized, retrospective chart review conducted between September 2018 and August 2019. The primary objective was to evaluate the utilization of rasburicase and appropriateness for the management of tumor lysis syndrome in pediatric and adult patients based on the Wake Forest Baptist Health tumor lysis syndrome pocket card. The secondary objectives were to assess response to prophylactic and treatment doses of rasburicase and to quantify drug cost versus expense of rasburicase utilization.

RESULTS

Overall, 64 patients (57 adults and 7 pediatric patients) were included in the study. Rasburicase use for tumor lysis syndrome indication adhered to the pocket card 64% of the time. Appropriate fluids and/or allopurinol were initiated in only 34% of patients. For monitoring, 80% of patients had all necessary tumor lysis syndrome laboratory values collected after rasburicase administration. All 11 patients (17%) who received rasburicase in the outpatient setting did not have follow-up labs collected. Of the patients who had tumor lysis syndrome laboratory values collected post rasburicase, 39% were appropriately timed to accurately assess efficacy of rasburicase with the median time of laboratory monitoring after rasburicase being 6.5 h. Response was observed with rasburicase 3 mg (92%), 6 mg (100%), and weight-based dosing (100%). The wholesale acquisition cost per patient was $5203 (1101-10,406). The potential cost savings of using the 3 mg dose versus the 6 mg dose for the patients who did not meet tumor lysis syndrome treatment recommendations based on the Wake Forest Baptist Health pocket card was estimated to be $36,419.46.

CONCLUSION

There are several opportunities for improvement in tumor lysis syndrome management and rasburicase utilization at our institution. This study will lead to the implementation of formal restrictions for rasburicase use and selection of rasburicase dose. Updating the rasburicase order panel to include appropriate prophylaxis and require input of uric acid level, populating pertinent tumor lysis syndrome laboratory values on the order verification screen for pharmacists to appropriately assess if rasburicase meets the institution restriction criteria, and providing education to providers on the appropriate ordering and timing of labs.

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.

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.

Decreasing Inappropriate Use of Rasburicase to Promote Cost-Effective Care

BACKGROUND

Rasburicase is a recommended treatment of tumor lysis syndrome and patients at high-risk for developing tumor lysis syndrome. Unfortunately, it is expensive, and unnecessary use raises costs of care.

METHODS

Plan, Do, Study, Act methodology was used to decrease the inappropriate use of rasburicase. In the Plan phase, a multidisciplinary quality improvement team reviewed the rasburicase ordering process and its prescription patterns at Parkland Health and Hospital System between October 2015 and September 2017 to determine appropriate interventions for improvement. In the Do phase, interventions were deployed to improve rasburicase prescriptions. In the Study phase, the team reviewed the rasburicase orders and appropriateness from February 2018 to October 2018. During the Act phase, the interventions were found to be successful, and the process changes were solidified.

RESULTS

At baseline, 65 doses of rasburicase were administered during the 2-year baseline period, 21 of these (32.3%) were inappropriate. Review of the ordering process identified pitfalls: one-click ready-to-sign order, fixed default dose, no hard-stop alert requiring physicians to review and confirm appropriate indications, and lack of secondary pharmacy review. We aimed to reduce the percentage of inappropriate rasburicase orders from a baseline of 32.3% to 10% over 3 months. In February 2018, we implemented the interventions, which resulted in reduction in inappropriate rasburicase use, with only a single inappropriate order placed in 7 months postintervention.

CONCLUSION

A multidisciplinary approach and classic quality improvement methodology enabled us to reduce inappropriate rasburicase use. Straightforward electronic medical record interventions and secondary pharmacy review are effective in addressing overuse.

A cost comparison of rasburicase versus dialysis in the management of children with acute leukaemia and lymphoma at a South African centre

Background: Tumour lysis syndrome is a common complication of haematological malignancies and has historically been managed with hyperhydration, urine alkalinisation and allopurinol with renal dialysis reserved for patients in acute renal failure. Rasburicase has been shown to drastically reduce the need for dialysis; however, its use is limited in developing countries owing to its cost and availability.Aim: This retrospective analysis aimed to compare the cost to state per patient of rasburicase compared to dialysis in the management and prevention of tumour lysis syndrome in paediatric patients presenting with haematological malignancies admitted to Red Cross War Memorial Children’s Hospital (RCWMCH).Setting: Red Cross War Memorial Children’s Hospital.Methods: Patients from two consecutive 35 month periods, before and after the availability of rasburicase at RCWMCH, were grouped according to treatment modality, and the cumulative costs of hospitalisation, dialysis and drug administration were compared.Results: The groups were comparable in mean age and gender. The mean total length of hospital stay was 10.04 days shorter for the rasburicase group than the dialysis group with the average cost per patient in the rasburicase group being R40 989.64 lower than the dialysis group.Conclusion: The use of rasburicase results in a significant per patient cost saving when compared to dialysis, which often requires intensive care admission, and results in extended hospitalisation. The study supports the continued use of rasburicase as an essential adjunct in the management and prevention of tumour lysis syndrome, reaffirming its use as a cost-effective and efficient drug.

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.

The value of fixed rasburicase dosing versus weight-based dosing in the treatment and prevention of tumor lysis syndrome

Background

Rasburicase is a recombinant urate oxidase enzyme used for the treatment and prevention of tumor lysis syndrome. Our objective was to assess the efficacy of indication-based, low-dose rasburicase administration compared to the Food and Drug Administration-approved weight-based dosing.

Methods

This was a retrospective cohort study utilizing data from a tertiary medical center including patients admitted from 2012 to 2016, who received at least one dose of rasburicase. The primary outcome was achieving a uric acid level less than 7.5 mg/dl after a single dose of rasburicase in the preprotocol (Food and Drug Administration-approved weight-based dosing) and postprotocol (indication-based, low-dose) groups. Secondary outcomes included the change in uric acid levels between the pre- and postprotocol groups, adherence to the new institutional protocol, need for repeat rasburicase doses, and a cost analysis.

Results

Sixty-four patients received at least one dose of rasburicase between 1 January 2012 and 1 December 2016. Twenty-seven (79.4%) doses in the preprotocol group and 28 (82.4%) doses in the postprotocol group successfully achieved a uric acid level less than 7.5 mg/dl after a single dose of rasburicase (p=1.000). The average total monthly cost of rasburicase was reduced by 59.9% after adoption of the new protocol.

Conclusions

Indication-based, low-dose rasburicase displayed significantly more value when compared to weight-based dosing as shown by achieving cost savings without compromising clinical efficacy.

Analysis of the incidence of tumor lysis syndrome in patients with hematological malignancies treated with rasburicase

The purpose of this study was to assess the incidence of tumor lysis syndrome (TLS) in patients with hematological malignancies treated with rasburicase, and to evaluate the dose and duration of rasburicase administration. A total of 52 patients were enrolled. The background of the patients, incidence of TLS and laboratory data were retrospectively examined; in addition, the dose and duration of rasburicase administration and the factors affecting the onset of TLS were evaluated and compared among TLS risk categories. During the study period, 2 (3.8%) of the patients developed clinical TLS and 24 (46.2%) developed laboratory TLS (LTLS). Although the LTLS rate was very high, there were no life-threatening cases of TLS. The median daily dose of rasburicase administered to all patients was 7.5 mg/day (interquartile range, 7.5-9.0 mg/day), and the daily weight-based dose was 0.147 mg/kg/day (range, 0.126-0.178 mg/kg/day). The administration duration was 3 days (interquartile range, 3-4 days). Additionally, there was no significant association between TLS risk classification and daily rasburicase administration dose, duration, or post-administration laboratory data. The factors affecting the onset of TLS included serum uric acid level, as well as serum creatinine and phosphate levels. Rasburicase was highly effective in the prevention and management of hyperuricemia, even at a low-dose (7.5 mg/day) and a duration that was 3 days shorter compared with that recommended by the manufacturer. Therefore, clinicians should administer rasburicase based on their clinical judgment, taking into consideration the cost-effectiveness of this therapy.

Emergencies in Hematology and Oncology

The development of medical emergencies related to the underlying disease or as a result of complications of therapy are common in patients with hematologic or solid tumors. These oncological emergencies can occur as an initial presentation or in a patient with an established diagnosis and are encountered in all medical care settings, ranging from primary care to the emergency department and various subspecialty environments. Therefore, it is critically important that all physicians have a working knowledge of the potential oncological emergencies that may present in their practice and how to provide the most effective care without delay. This article reviews the most common oncological emergencies and provides practical guidance for initial management of these patients.

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.

Rational use of rasburicase for the treatment and management of tumor lysis syndrome

Purpose There is a lack of high-level evidence identifying meaningful outcomes and the optimal place in therapy of rasburicase in patients with, or at high risk for tumor lysis syndrome. The primary objective of this study was to evaluate and characterize outcomes resulting from an institution-specific guideline emphasizing supportive care, xanthine oxidase inhibitors, and lower doses of rasburicase. Methods In this retrospective chart review, we compared conservative rasburicase dosing, in accordance with newly developed UMHS tumor lysis syndrome guidelines, with aggressive rasburicase in adult patients (≥ 18 years of age) with hematological or solid tumor malignancies, and a uric acid level between 8 and 15 mg/dL. The primary efficacy outcome assessed the difference in the proportion of patients achieving a uric acid level <8 mg/dL within 48 h using a one-sided noninferiority test. The principle safety outcomes analyzed included incidence of acute kidney injury and hemodialysis requirement. Results One hundred sixty-one patients met inclusion criteria and were included in the study. Within 48 h of an elevated uric acid level, treatment was successful in 97.03% of patients in the conservative group, as compared with 98.33% in the aggressive group (difference, 1.3 percentage points; 95% confidence interval [CI], -3.33 to 5.93). Furthermore, there was no difference in the proportion of patients requiring hemodialysis (2.97% vs. 10.0%, p-value 0.079), or incidence of acute kidney injury (4.0% vs. 12.5%, p-value 1.00) between the treatment group and control group, respectively. Conclusions Conservative rasburicase use was noninferior to aggressive rasburicase use in patients with or at high risk for tumor lysis syndrome.

Renal dysfunction following bone marrow transplantation

Acute kidney injury and long-term renal dysfunction are common problems following bone morrow transplantation (BMT) and highly related to mortality. The frequency and risk of renal dysfunction are directly related to the method of BMT, with myeloablative allogeneic BMT being associated to the highest risk followed by non-myeloablative allogeneic and myeloablative autologous BMT. The type of BMT is, thus, more important than co-factors such as advanced age, comorbidities, or high baseline serum creatinine. The causes for renal failure are multiple and include chemotherapy and high-dose radiation with fluid loss by diarrhea or vomiting, sepsis or nephrotoxic drugs such as calcineurin inhibitors and antimicrobials. Additionally, there are BMT-specific reasons for renal dysfunction including marrow infusion toxicity, hepatic veno-occlusive disease, thrombotic microangiopathy (TMA) and graft versus host disease (GvHD). Once the kidney has been damaged, the therapy depends on the underlying disease. Particularly in cases of TMA and GvHD, immunosuppressive therapy is essential. In TMA, plasma exchange therapy or eculizumab should be additionally considered if the complement system is affected. Hence, patients with these causes should preferably be referred to tertiary centers to allow early diagnosis and appropriate treatment.

Acute kidney injury in hematological patients

PURPOSE OF REVIEW

The present article reviews the recent literature on the main aspects of acute kidney injury (AKI) developing in patients with hematological malignancies admitted to ICU.

RECENT FINDINGS

Up to two thirds of critically ill patients with hematological malignancies develop AKI. Current mortality rates range from 40 to 60% for most patients with hematological malignancies, except for recipients of allogeneic hematopoietic stem cell transplantation in whom outcomes remain very poor. Renal function recovery occurs in most patients with AKI, but is dependent on the underlying causes. AKI is usually multifactorial, resulting from causes common to other ICU patients and related to the underlying malignancy or its treatment. New targeted therapies and treatment strategies are potentially associated with AKI. Management of these patients requires a high degree of suspicion, close monitoring of metabolic parameters, and use of preventive strategies to limit risk of AKI or to mitigate its severity.

SUMMARY

AKI is a frequent and severe complication in critically ill patients with hematological malignancies. As the clinical management is complex, close collaboration with hematologists is paramount.

Allopurinol hypersensitivity syndrome in patients with hematological malignancies: characteristics and clinical outcomes

BACKGROUND/AIMS

Allopurinol is a urate-lowering agent that is commonly used to prevent chemotherapy-related hyperuricemia. Allopurinol hypersensitivity syndrome (AHS) is a disorder involving multiple organs, which may be accompanied by cutaneous adverse reactions. We identified the characteristics and clinical outcomes of chemotherapy-associated AHS in patients with hematological malignancies.

METHODS

This retrospective single-center study included 26 AHS patients (11 with and 15 without hematological malignancies) admitted to Seoul St. Mary's Hospital. AHS was defined using the criteria of Singer and Wallace. Comparisons were made using the Mann-Whitney U test and Fisher exact test as appropriate.

RESULTS

In patients with a hematological malignancy and AHS, statistically significant differences were observed in terms of younger age at onset; shorter duration of exposure; higher starting and maintenance doses of allopurinol; lower incidence of eosinophilia, leukocytosis, and underlying renal insufficiency; and more frequent occurrence of fever compared to AHS patients without a hematological malignancy. Two AHS patients with a hematological malignancy were examined for human leukocyte antigen (HLA)-B typing, but neither patient harbored the HLA-B*5801 allele. All of the patients ceased allopurinol treatment, with most patients making a full recovery. Two patients in the study died; however, these deaths were unrelated to AHS. One patient developed serious sequelae of AHS that required hemodialysis.

CONCLUSIONS

Physicians who prescribe allopurinol for the prevention of chemotherapy-related hyperuricemia should be aware of the unique risk of AHS, even in patients with hematological malignancies who do not have known risk factors for AHS. Novel urate-lowering agents should be considered alternative treatments.

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.

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.