A single, fixed dose of rasburicase (6 mg maximum) for treatment of tumor lysis syndrome in adults

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.

Tumor lysis syndrome: new challenges and recent advances

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

One for the road! A study to assess the efficacy of single low-dose regimen of rasburicase in controlling hyperuricaemia in patients with tumour lysis syndrome due to haematological malignancies

We conducted a retrospective audit of six patients with various haematological malignancies (two acute lymphoblastic leukaemia, one acute myeloid leukaemia, and three non-Hodgkin lymphoma); these patients were eligible to receive rasburicase, being at high risk of development of tumour lysis syndrome (TLS). They received a fixed single low-dose regimen of rasburicase (7.5 mg) mainly due to financial restriction, as patients were not supported by the National Health Service and did not have health insurance. We compared uric acid, creatinine levels, and electrolytes (i.e. phosphate, potassium, and calcium) before and after rasburicase administration and also assessed the need for renal replacement therapy after treatment.

All six patients had a significant reduction in uric acid levels on the first day, achieving a response rate of 100% (p = 0.008994); creatinine, phosphate, and potassium were reduced significantly as well, with the p values of 0.0439, 0.014326, and 0.002008, respectively; only one patient needed renal replacement therapy in the form of haemodialysis, due to concerns about hyperphosphataemia.

Financial difficulties faced either because patients lacked insurance or because of the restricted National Health Service budget in Egypt have resulted in the unavailability of certain modalities of treatment in cancer care and the need to consider more economic yet efficient approaches. Our experience suggests that a single low-dose rasburicase injection (7.5 mg) is an efficient and cost-effective method to control hyperuricaemia in patients with a high risk of developing TLS when compared with the more expensive and extended standard regimen and doses recommended.

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

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