Rasburicase (recombinant urate oxidase) for the management of hyperuricemia in patients with cancer: report of an international compassionate use study

BACKGROUND: Hyperuricemia and tumor lysis syndrome (TLS) are serious complications that can occur during chemotherapy for hematologic malignancies, even if standard management procedures, including administration of allopurinol, are undertaken. Rasburicase, a recombinant urate oxidase that converts uric acid (UA) into the soluble compound allantoin, has been shown to control hyperuricemia faster and more reliably than allopurinol.(1) METHODS: A compassionate use trial, running from January 1999 to December 2001, provided access to rasburicase for patients in nine countries who were at risk for TLS during the initiation of chemotherapy. Of the 280 patients enrolled in the study, 278 received rasburicase and were included in the analysis. A total of 166 pediatric patients who had leukemia (approximately 74%), lymphoma (approximately 24%), or solid tumors (approximately 3%) were treated with rasburicase. One hundred twelve adults with either leukemia (68%) or lymphoma (30%) also were treated. Rasburicase (0.20 mg/kg) was administered intravenously once a day for 1 to 7 days, at the investigator's discretion. Two doses daily could be administered during the first 3 days. A response was defined as a reduction in UA level or maintenance of a UA level less than 7.5 mg/dL (or less than 6.5 mg/dL, for children age < 13 years). RESULTS: UA levels at 24-48 hours after administration of the last dose of rasburicase were available for 122 pediatric patients and 97 adult patients. The mean UA level in 29 hyperuricemic children decreased from 15.1 mg/dL to 0.4 mg/dL, whereas in 27 hyperuricemic adults, the mean level decreased from 14.2 mg/dL to 0.5 mg/dL. Prophylactic administration of rasburicase to prevent TLS during chemotherapy reduced UA levels from a mean of 4.4 mg/dL to 0.8 mg/dL in 93 nonhyperuricemic children and from 4.8 mg/dL to 0.4 mg/dL in 70 nonhyperuricemic adults (for all reductions in UA levels, P < 0.001). The response rate was 100%. Rasburicase was very well tolerated. Serious adverse events related to rasburicase were observed in one patient. CONCLUSIONS: The results of the current study confirm that rasburicase is safe and highly effective in the prevention and treatment of chemotherapy-induced hyperuricemia in both children and adults.     

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

BackgroundTumor lysis syndrome (TLS) is a life-threatening disorder characterized by hyperuricemia and metabolic derangements. The efficacy of rasburicase, administered daily for 5 days, has been well established. However, the optimal duration of therapy is unknown in adults.Patients and methodsWe evaluated the efficacy of rasburicase (0.15 mg/kg) administered as single dose followed by as needed dosing (maximum five doses) versus daily dosing for 5 days in adult patients at risk for TLS.ResultsEighty of the 82 patients enrolled received rasburicase; 40 high risk [median uric acid (UA) 8.5 mg/dl; range, 1.5–19.7] and 40 potential risk (UA = 5.6 mg/dl; range, 2.4–7.4). Seventy-nine patients (99%) experienced normalization in their UA within 4 h after the first dose; 84% to an undetectable level (<0.7 mg/dl). Thirty-nine of 40 (98%) patients in the daily-dose arm and 34 of 40 (85%) patients in single-dose arm showed sustained UA response. Six high-risk patients within the single-dose arm required second dose for UA >7.5 mg/dl. Rasburicase was well tolerated; one patient with glucose-6-phosphate dehydrogenase deficiency developed methemoglobinemia and hemolysis.ConclusionsRasburicase is highly effective for prevention and management of hyperuricemia in adults at risk for TLS. Single-dose rasburicase was effective in most patients; only a subset of high-risk patients required a second dose.     

Single dose rasburicase in tumor lysis: One hospital's experience

Background: Tumor lysis syndrome is an oncological emergency occurring mainly in high‐grade hematological malignancies. It results in significant biochemical abnormalities including hyperuricemia and acute renal failure. Rasburicase is a recombinant urate oxidase enzyme that catalyzes oxidation of uric acid into allantoin, which is easily excreted in the urine. Reports in the literature suggest that a single dose of rasburicase is effective in treating tumor lysis syndrome, whereas the current dose recommended by the manufacturer is 0.2 mg/kg/day for 5 to 7 days, which is very costly ($13 000 for an average 70‐kg person). We present a retrospective analysis on the patients at our hospital that have received rasburicase as a single dose. Methods: Medical and pharmacy dispensing records were searched to identify patients with high‐grade hematological malignancy who received a single dose of rasburicase in a 12‐month period. Data on renal function, electrolytes, and uric acid were obtained. Results: Twenty‐three patients were newly diagnosed with high‐grade hematological malignancy (Burkitt lymphoma 4, AML 17, APML 1, DLBCL 1). A single dose of rasburicase 0.2 mg/kg was administered to six of these patients considered to be at high risk, five of whom had an elevated uric acid level before treatment. Their uric acid levels were monitored from 24 h to 96 h after this dose. Normal uric acid levels were seen in all patients within 24 h. These levels remained normal for 96 h. One of five patients died of pre‐existing renal failure despite the normalization of their uric acid. Conclusion: We conclude that single dose rasburicase is effective in the treatment of hyperuricemia in patients at risk of tumor lysis and effectively reduces the level of uric acid for up to 96 h. This makes it cost effective and theoretically reduces the risk of hypersensitivity associated with rasburicase.     

Effectiveness of Single-dose Rasburicase in Patients With Lymphoid Malignancies at a High Risk for Tumor Lysis Syndrome

BackgroundTumor lysis syndrome (TLS) is a life-threatening disorder that occurs mainly in patients with high-tumor burden hemato-oncologic malignancies. It results in metabolic derangements, including hyperuricemia and acute renal failure. The powerful management for TLS is a daily dose of rasburicase for up to 5 days before chemotherapy; however, the optimal dose and duration of rasburicase for TLS prophylaxis have not been standardized for patients at high risk for TLS. Therefore, we evaluated the efficacy of single-dose rasburicase for prophylactic purposes in patients with malignant lymphoma at high risk for TLS.Patients and MaterialsWe retrospectively evaluated patients with malignant lymphoma at high risk for TLS treated with a prophylactic single-dose of rasburicase (0.1-0.2 mg/kg) from March 2012 to March 2016.ResultsA total of 67 patients treated with a single-dose of rasburicase for prophylaxis were analyzed. A relatively large number of patients (n = 23; 34.3%) had the highly proliferative lymphoblastic lymphoma subtype (n = 14) or Burkitt lymphoma (n = 9) and were at the highest risks of tumor lysis. Two patients were newly diagnosed with TLS; the incidence of TLS after single-dose prophylaxis was 3.0%. Multivariate analysis revealed no predictable risk factors for response to prophylactic rasburicase, though increased level of serum creatinine approached statistical significance in reducing the efficacy of single-dose rasburicase to prevent TLS (odds ratio, 3.61; P = .054).ConclusionOur data indicated that single-dose rasburicase effectively prevented progression of TLS, and, regardless of any risk factors, including increased creatinine, single-dose rasburicase for TLS prophylaxis was useful in patients with lymphoma at a high risk for TLS.     

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

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

Efficacy and safety of rasburicase (recombinant urate oxidase) for the prevention and treatment of hyperuricemia during induction chemotherapy of aggressive non-Hodgkin's lymphoma: results of the GRAAL1 (Groupe d'Etude des Lymphomes de l'Adulte Trial on Rasburicase Activity in Adult Lymphoma) study.

PURPOSE: Hyperuricemia and tumor lysis syndrome are well-known complications during induction treatment of aggressive non-Hodgkin's lymphomas (NHLs). Usual prophylaxis and treatment of hyperuricemia consist of hydration, alkalinization, and administration of allopurinol. This study was designed to evaluate the efficacy and the safety of rasburicase (recombinant urate oxidase) in adult patients with aggressive NHL during their first cycle of chemotherapy. PATIENTS AND METHODS: A total of 100 patients from Groupe d'Etude des Lymphomes de l'Adulte centers, with diffuse large B-cell lymphoma (n = 79); anaplastic large-cell lymphoma (n = 6); peripheral T-cell lymphoma (n = 8); transformation of indolent lymphoma (n = 5); Burkitt's lymphoma (n = 1); and lymphoblastic lymphoma (n = 1) were enrolled from May 2001 to June 2002. Before chemotherapy, 66% of patients had elevated lactate dehydrogenase (LDH), including 28% with LDH above 1,000 U/mL. Eleven percent of patients were hyperuricemic (uric acid [UA] > 450 mmol/L or > 7.56 mg/dL). Rasburicase 0.20 mg/kg/d intravenously for 3 to 7 days was started the day before or at day 1 of chemotherapy. UA levels were measured 4 hours after rasburicase injection, then daily during treatment. RESULTS: All patients responded to rasburicase, as defined by normalization of UA levels maintained during chemotherapy. The control of UA was obtained within 4 hours after the first injection of the drug. Creatinine levels and other metabolites were also controlled with the administration of rasburicase. No patient exhibited increased creatinine levels or required dialysis during chemotherapy. CONCLUSION: Rasburicase is the treatment of choice to control UA and prevent tumor lysis syndrome in adult patients with aggressive NHL.     

Recombinant urate oxidase for prevention of hyperuricemia and tumor lysis syndrome in lymphoid malignancies

Hyperuricemia is a common manifestation of lymphoid malignancies at diagnosis or after the start of chemotherapy. When accompanied by other metabolic abnormalities and/or organ failure, hyperuricemia may be a manifestation of tumor lysis syndrome (TLS). Patients at particularly high risk of such complications include those with acute lymphoblastic leukemia and advanced stage non-Hodgkin's lymphoma. Conventional measures to prevent hyperuricemia and TLS are comprised of hydration, alkalinization of body fluids, and administration of allopurinol. Although these measures are usually effective in preventing or managing hyperuricemia, approximately 20% of patients at high risk of TLS require dialysis, and many cannot receive chemotherapy as planned. Rasburicase, a recombinant form of the enzyme urate oxidase, has recently become available and may further reduce the morbidity of hyperuricemia and TLS. In this review, we provide an overview of hyperuricemia and TLS and discuss the impact of rasburicase in the overall management of these complications.     

Prevention and treatment of hyperuricemia in hematological malignancies

The standard prophylactic and treatment regimen for hyperuricemia in patients with hematological malignancies previously included vigorous hydration, urinary alkalinization, and a xanthine oxidase inhibitor, allopurinol, which blocks the conversion of hypoxanthine and xanthine to uric acid. However, xanthine is less soluble than uric acid, and preexisting uric acid is not affected by allopurinol. The enzyme urate oxidase, not present in mammals, converts uric acid to allantoin, which is 5-10 times more soluble than uric acid. A new recombinant form of urate oxidase, rasburicase, has recently been developed. In a phase I/II study of rasburicase in children and young adults with hematological malignancies, rasburicase was demonstrated to be well tolerated at 0.2 mg/kg/day intravenously, had a mean T1/2 of 21.2 +/- 12.0 hours, and induced a median decrease in uric acid from 9.7 mg/dL to 1.0 mg/dL (P < 0.001). We recently demonstrated, in a randomized prospective trial comparing rasburicase versus allopurinol in children with hematological malignancies at high risk of tumor lysis syndrome, that rasburicase significantly lowered the mean uric acid area under the curve 0 to 96 hours (128 +/- 70 mg/dL/hour vs. 329 +/- 129 mg/dL/hour; P < 0.001) and 4 hours post uric acid by 86% versus 12% (P < 0.001). Furthermore, in the hyperuricemic group, the baseline creatinine level decreased from 144% to 102% by 96 hours following rasburicase compared to an increase from 132% to 147% following allopurinol. Although the difference in effect on creatinine levels is not significant, the study was not designed or powered to question this effect. Lastly, in 510 patients with hematological malignancies at risk for tumor lysis syndrome who received rasburicase, only 2 (0.4%) have developed new renal complications requiring hemodialysis. In summary, in the prevention and treatment of hyperuricemia, patients with hematological malignancies at risk of tumor lysis syndrome appear to benefit significantly from the use of a recombinant urate oxidase (rasburicase).     

The Effective Control of Hyperuricemia in Cancer Patients: A New Recombinant Conjugated Variant of Urate Oxidase

Objective: Management of hyperuricemia is crucial to controlling tumor lysis syndrome (TLS) during cancer therapy. Urate oxidase (UOX) that catalyzes the enzymatic oxidation of uric acid into allantoin, is effective in lowering plasma uric acid levels and controlling hyperuricemia. Recently, we developed a new recombinant conjugate variant of UOX therapeutic drug using PASylation technology. This study was designed to evaluate the stability, plasma half-life and immunogencity of PASylated UOX. Methods: A recombinant variant of PASylated UOX from the Aspergillus flavus was manufactured using bioinformatics and experimental techniques. Ex vivo evaluation of stability of PASylated UOX was done in 50% human serum. For half-life test, recombinant PASylated UOX and rasburicase were administered at 1.5 mg/kg to 10 rats in two different groups and samples were collected after injection Production of antibodies against PASylated drug was also assayed. Results: Residual activity of PASylated UOX in 50% human serum was higher than rasburicase and native UOX. Stability of PASylated UOX at 25°C and 37°C was also higher than rasburicase and native UOX. The PASylated half-life was ~32.1 hours, whereas half-life for rasburicase and native UOX was ~25.1 and ~22.8 hours, respectively. In immunogenicity examination, there is 33% and 36% decrease in the absorbance of native UOX and rasburicase, respectively when compared with that of PASylated UOX. Conclusion: Our data confirmed the efficacy and stability of PASylated UOX in comparison to the rasburicase. In summary, the results indicated that PASylated UOX drug is effective at lowering plasma uric acid levels with prolonged plasma half-life and decreased cost.     

Rasburicase: potential role in managing tumor lysis in patients with hematological malignancies

Acute tumor lysis syndrome with hyperuricemia and renal failure usually occurs during the initial period of chemotherapy in patients with aggressive hematological malignancies. Standard therapy for hyperuricemia includes hydration, urine alkalinization and pharmacoreduction of uric acid with allopurinol. In the USA, rasburicase has recently been approved by the US Food and Drug Administration for the reduction of uric acid. Rasburicase is a recombinant urate oxidase enzyme that converts uric acid to allantoin, which has increased urine solubility. It is administered intravenously once-daily and leads to rapid, dramatic declines in serum uric acid values. The toxicity profile is excellent, with rare incidence of bronchospasm and allergies and a known contraindication for patients with glucose-6-phosphate dehydrogenase deficiency. A Phase III trial in high-risk pediatric patients conclusively demonstrated that rasburicase is more effective than allopurinol in controlling uric acid. Ongoing evidence is accumulating suggesting that the drug is also safe and effective in adults with hematological malignancies.     

Rasburicase: potential role in managing tumor lysis in patients with hematological malignancies

Acute tumor lysis syndrome with hyperuricemia and renal failure usually occurs during the initial period of chemotherapy in patients with aggressive hematological malignancies. Standard therapy for hyperuricemia includes hydration, urine alkalinization and pharmacoreduction of uric acid with allopurinol. In the USA, rasburicase has recently been approved by the US Food and Drug Administration for the reduction of uric acid. Rasburicase is a recombinant urate oxidase enzyme that converts uric acid to allantoin, which has increased urine solubility. It is administered intravenously once-daily and leads to rapid, dramatic declines in serum uric acid values. The toxicity profile is excellent, with rare incidence of bronchospasm and allergies and a known contraindication for patients with glucose-6-phosphate dehydrogenase deficiency. A Phase III trial in high-risk pediatric patients conclusively demonstrated that rasburicase is more effective than allopurinol in controlling uric acid. Ongoing evidence is accumulating suggesting that the drug is also safe and effective in adults with hematological malignancies.     

Management of tumor lysis syndrome with a single fixed dose of rasburicase in Asian lymphoma patients: a case series and literature review

Aim: Recently, a number of studies have demonstrated the effectiveness of a single reduced dose of rasburicase for the management of tumor lysis syndrome (TLS) in adults. Whether Asian lymphoma patients similarly respond to a single dose of rasburicase is currently unknown. We aim to assess the efficacy of a single dose rasburicase in preventing TLS in Asian lymphoma patients. Methods: This was a single‐center case series of adult lymphoma patients at high risk of TLS who received a single fixed dose of rasburicase. Patients had to have their uric acid, serum creatinine, lactate dehydrogenase and electrolytes monitored for at least 24–48 h post‐administration. Results: Eleven patients were identified. Majority were Chinese (91%), male (64%) and with a median age of 61 years (range 41–84). All had at least two risk factors for developing TLS. Ten patients received a 6‐mg dose and one received 4.5 mg. Prior to rasburicase administration, the mean uric acid level was 835 µmol/L (range 318–1237 µmol/L) and the level 24‐h post‐administration was 186 µmol/L (range 30–653 µmol/L) (P < 0.001). Eight patients (73%) experienced an improvement of renal function 72‐h post‐rasburicase. Normalization of serum electrolytes was achieved within 96 h. Conclusion: Among Asian lymphoma patients who manifested at least two risk factors for developing TLS, a single fixed dose of rasburicase at 6 mg is deemed to be effective for rapidly lowering uric acid levels as well as sustaining reduced levels for up to 72 h.     

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

IntroductionTumor 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 MethodsEighty-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.ResultsWe 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.ConclusionRasburicase 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.     

Challenges in the management of Burkitt's lymphoma

Burkitt's lymphoma and small noncleaved Burkitt's-like lymphoma are rare and are highly aggressive forms of non-Hodgkin's lymphoma that are characterized by dysregulation of the c-myc oncogene. Patients with human immunodeficiency virus (HIV) also appear to be at risk for developing Burkitt's lymphomas. Treatment options for Burkitt's lymphoma involve complex chemotherapy regimens that contain as many as 10 cytotoxic agents. Approximately 50%-80% of adult patients with Burkitt's lymphoma or small, noncleaved lymphoma can be cured with these intensive chemotherapy regimens, and in pediatric populations, the cure rate is even higher. However, a number of factors often compromise the outcome of patients with Burkitt's lymphoma. For instance, the high proliferation rate of Burkitt's lymphoma enhances the risk for tumor lysis syndrome, which results from metabolic imbalances, such as hyperuricemia, that occur as large numbers of malignant cells are lysed during cytotoxic chemotherapy. Standard treatment for tumor lysis syndrome includes adjustments in the chemotherapy regimen, vigorous hydration, administration of a uric acid synthesis inhibitor like allopurinol, and alkalinization. The administration of recombinant urate oxidase (rasburicase) also has been shown to provide effective prophylaxis against hyperuricemia in pediatric and adult patients with hematologic malignancies. The lifetime risk of developing central nervous system disease is 20%-30% for Burkitt's lymphoma. Consequently all chemotherapy regimens with activity in Burkitt's lymphoma utilize some form of central nervous system prophylaxis, such as systemic or intrathecal methotrexate or cytarabine. In the past, patients with HIV who developed Burkitt's lymphoma often received inadequate chemotherapy doses because of their immunosuppression. With the discovery of highly active antiretroviral therapy, the ability to treat and control Burkitt's lymphoma in patients with HIV has improved.     

The management of tumor lysis syndrome

The manifestation of tumor lysis syndrome (TLS) occurs when the destruction of tumor cells releases breakdown products that overwhelm the excretory mechanisms of the body. A cardinal sign is hyperuricemia, leading to uric acid nephropathy. Other signs are hyperkalemia, hyperphosphatemia and secondary hypocalcemia. Conventional management of TLS consists of aggressive intravenous hydration, diuretic therapy, urinary alkalization, and inhibition of urate production by high-dose allopurinol. Urate oxidase has been used in the management of patients at risk for TLS and recently the recombinant urate oxidase rasburicase was developed. Several data indicate that rasburicase is effective and well tolerated in the prevention and treatment of chemotherapy-induced hyperuricemia. Treatment options of hyperkalemia include sodium polystyrene sulfonate, hypertonic glucose and insulin, loop diuretics, and bicarbonate. Treatment of hyperphosphatemia reduces dietary phosphate intake and includes phosphate binders such as aluminum hydroxide and aluminum carbonate. When recurrent hypocalcemia is present, a continuous intravenous infusion of calcium gluconate can be initiated. Hemodialysis should be considered for every patient with excessively elevated uric acid, phosphate and/or potassium and in those patients with acute renal failure to control urinary volume and manage uremia.     

Managing malignancy-associated hyperuricemia with rasburicase

Along with hydration and urinary alkalinization, allopurinol has been the standard agent for the management of hyperuricemia in patients with a high tumor burden who are at risk for tumor lysis syndrome. However, this agent often fails to prevent and treat this complication effectively. Rasburicase, a recombinant urate oxidase, acts at the end of the purine catabolic pathway and, therefore, does not induce accumulation of xanthine or hypoxanthine, which can precipitate in the kidneys and lead to impaired renal function. Rasburicase may represent an effective alternative to allopurinol in rapidly reducing uric acid levels, improving patients' electrolyte status, and reversing renal insufficiency. The drug initially was studied in pediatric patients with acute lymphoblastic leukemia and aggressive non-Hodgkin lymphoma; data may suggest comparable benefit in adults with similar lymphoid malignancies. Current and future trials will evaluate alternate doses and schedules of rasburicase to maintain its efficacy while reducing its cost.     

Tumour lysis syndrome in children: experience of last decade

The strategy against tumour lysis syndrome (TLS) had been hyperhydration, urine alkalinization, and allopurinol. Recently, rasburicase was added to the armament against this life-threatening condition. In Korea, rasburicase is used as a rescue therapy for cases with allopurinol-resistant hyperuricemia, because of the restriction by the National Health Insurance. We reviewed our experiences to re-assess the risk factors of TLS and the efficacy of rasburicase. Medical records were retrospectively reviewed for 396 children who were diagnosed as positive with acute leukemia and non-Hodgkin lymphoma between the years 2000 and 2009. The risk factors for TLS were analyzed statistically, and those before and after the availability of rasburicase were compared. Sixty eight patients (17.2%) had TLS. Multivariate analysis showed that pre-chemotherapy hypophosphatemia was a risk factor for TLS, in addition to the known risk factors of hyperuricemia and high lactate dehydrogenase concentration. The availability of rasburicase as a rescue therapy did not negate the importance of uric acid as a risk factor of TLS. Rasburicase as a second line treatment for intractable hyperuricemia was not effective in reducing the incidence of TLS. Pre-chemotherapy hypophosphatemia was a significant independent risk factor for TLS.     

EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer: 2006 update

Anaemia is frequently diagnosed in patients with cancer, and may have a detrimental effect on quality of life (QoL). We previously conducted a systematic literature review (1996-2003) to produce evidence-based guidelines on the use of erythropoietic proteins in anaemic patients with cancer.[Bokemeyer C, Aapro MS, Courdi A, et al. EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer. Eur J Cancer 2004;40:2201-2216.] We report here an update to these guidelines, including literature published through to November 2005. The results of this updated systematic literature review have enabled us to refine our guidelines based on the full body of data currently available. Level I evidence exists for a positive impact of erythropoietic proteins on haemoglobin (Hb) levels when administered to patients with chemotherapy-induced anaemia or anaemia of chronic disease, when used to prevent cancer anaemia, and in patients undergoing cancer surgery. The addition of further Level I studies confirms our recommendation that in cancer patients receiving chemotherapy and/or radiotherapy, treatment with erythropoietic proteins should be initiated at a Hb level of 9-11 g/dL based on anaemia-related symptoms rather than a fixed Hb concentration. Early intervention with erythropoietic proteins may be considered in asymptomatic anaemic patients with Hb levels 11.9 g/dL provided that individual factors like intensity and expected duration of chemotherapy are considered. Patients whose Hb level is below 9 g/dL should primarily be evaluated for need of transfusions potentially followed by the application of erythropoietic proteins. We do not recommend the prophylactic use of erythropoietic proteins to prevent anaemia in patients undergoing chemotherapy or radiotherapy who have normal Hb levels at the start of treatment, as the literature has not shown a benefit with this approach. The addition of further supporting studies confirms our recommendation that the target Hb concentration following treatment with erythropoietic proteins should be 12-13 g/dL. Once this level is achieved, maintenance doses should be titrated individually. There is Level I evidence that dosing of erythropoietic proteins less frequently than three times per week is efficacious when used to treat chemotherapy-induced anaemia or prevent cancer anaemia, with studies supporting the use of epoetin alfa and epoetin beta weekly and darbepoetin alfa given every week or every 3 weeks. We do not recommend the use of higher than standard initial doses of erythropoietic proteins with the aim of producing higher haematological responses, due to the limited body of evidence available. There is Level I evidence that, within reasonable limits of body weight, fixed doses of erythropoietic proteins can be used to treat patients with chemotherapy-induced anaemia. This analysis confirms that there are no baseline predictive factors of response to erythropoietic proteins that can be routinely used in clinical practice if functional iron deficiency or vitamin deficiency is ruled out; a low serum erythropoietin (EPO) level (only in haematological malignancies) appears to be the only predictive factor to be verified in Level I studies. Further studies are needed to investigate the value of hepcidin, c-reactive protein, and other measures as predictive factors. In these updated guidelines, we explored a new question of whether oral or intravenous iron supplementation increases the response rate to erythropoietic proteins. We found no evidence of increased response with the addition of oral iron supplementation, but there is Level II evidence of improved response to erythropoietic proteins with the addition of intravenous iron. However, the doses and schedules for intravenous iron supplementation are not yet well defined, and further studies in this area are warranted. The two major goals of erythropoietic protein therapy are prevention or elimination of transfusions and improvement of QoL. The total body of evidence shows that red blood cell (RBC) transfusion requirements are reduced following treatment with erythropoietic proteins. This analysis also confirms that QoL is significantly improved in patients with chemotherapy-induced anaemia and in those with anaemia of chronic disease following erythropoietic protein therapy, with more robust evidence now available that QoL was improved in studies investigating early intervention in cases of chemotherapy- or radiotherapy-induced anaemia. There is only indirect evidence that patients with chemotherapy-induced anaemia or anaemia of chronic disease initially classified as non-responders to standard doses proceed to respond to treatment following a dose increase. None of the studies addressed the question in a prospective, randomised fashion, and so the Taskforce does not recommend dose escalation as a general approach in all patients who are not responding. There is still insufficient data to determine the effect on survival following treatment with erythropoietic proteins in conjunction with chemotherapy or radiotherapy. Our analysis of survival endpoints in studies involving patients receiving radio(chemo)therapy found that most studies were inconclusive, with no clear link between the use of erythropoietic proteins and survival. Likewise, we found no clear link between erythropoietic therapy and other endpoints such as local tumour control, time to progression, and progression-free survival. There is no evidence that pure red cell aplasia occurs in cancer patients following treatment with erythropoietic proteins, and the fear of this condition developing should not lead to erythropoietic proteins being withheld in patients with cancer. There is Level I evidence that the risk of thromboembolic events and hypertension are slightly elevated in patients with chemotherapy-induced anaemia receiving erythropoietic proteins. Additional trials are warranted, especially to define the optimal doses and schedules of intravenous iron supplementation during erythropoietic therapy. While our review did not address cost benefit evaluations in detail, the consensus is that studies taking into account all real determinants of cost and benefit need to be performed prospectively.     

Systematic review: generating evidence-based guidelines on the concurrent use of dietary antioxidants and chemotherapy or radiotherapy

The risk-benefit ratio for concurrent use of dietary antioxidants with chemotherapy or radiation therapy is a controversial topic. In this review, the medical literature on concurrent antioxidant use with chemotherapy or radiotherapy was assessed and further steps for generating evidence-based guidelines are suggested. The clinical cancer research community should cooperate and focus new studies on the use of a specific combination of antioxidant and chemotherapy or radiotherapy, and determine optimal doses for a specific cancer setting. Mechanistic studies on the interaction between antioxidants and conventional cancer therapy could lead to novel biomarkers for assessing dose adequacy.     

Prevention and treatment of hyperuricemia with rasburicase in children with leukemia and non-Hodgkin’s lymphoma

To prevent acute renal failure in children at risk for developing tumor lysis syndrome due to acute lymphoblastic leukemia or non-Hodgkin’s lymphoma treated according to international BFM protocols, we investigated recombinant urate oxidase (rasburicase) in the first Central European openlabeled, prospective, multicenter phase IV trial. Rasburicase was administered intravenously, at 0.2 mg/kg for 5 consecutive days to 36 patients. Blood levels of uric acid, creatinine, phosphorus, calcium, lactate dehydrogenase and complete blood count were measured daily during rasburicase treatment and on days 6, 7 and 12. Initial uric acid level decreased significantly by 4 hours (from 343 μmol/L to 58 μmol/L, p<0.001), except for one steroid-resistant patient who required hemodialysis on day 14 after having introduced combined cytostatic treatment. Comparing the data of a subgroup of 12 patients receiving rasburicase with that of a historic cohort of 14 patients treated with allopurinol indicated the superiority of rasburicase over allopurinol in prophylaxis and treatment of hyperuricemia in children with leukemia and lymphoma. Both authors contributed equally to this work. The study of the investigational new drug was approved and it was provided by Sanofi-Synthelabo Inc., Budapest, Hungary. This work was supported by the grant of the Health Science Council of the Ministry of Health, Republic of Hungary (ETT) No. 225.