A study using real-world data for patients with tumor lysis syndrome (TLS) showed that treatment with rasburicase (Elitek) was associated with significantly greater reductions in uric acid, length of hospital stay, and total hospitalization costs per patient compared with allopurinol (Zyloprim).
TLS, which is a consequence of either tumor treatment or spontaneous tumor death, is an oncologic emergency. TLS can lead to renal failure, seizures, severe muscle weakness, tetany, cardiac arrhythmias, and death. The treatment options for TLS include allopurinol and rasburicase.
“Although rasburicase is a higher-priced drug, it holds the potential for reduced inpatient costs and may, therefore, provide a more cost-effective treatment option than allopurinol,” said Mitchell S. Cairo, MD, Chief, Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, at New York Medical College, Valhalla, NY, and Director of the Children’s and Adolescent Cancer and Blood Diseases Center and Medical and Scientific Director of the Stem and Cellular Therapy Laboratory at Westchester Medical Center, New York.
Dr Cairo presented the results of a retrospective cohort study of administrative data from the Health Facts database, which includes comprehensive pharmacy, laboratory, admission, and billing records from more than 400 hospitals. Using propensity scores, patients treated with rasburicase were matched 1 to 4 with patients treated with allopurinol according to multiple factors.
The study evaluated the potential cost-effectiveness of rasburicase compared with allopurinol in patients with TLS who were identified by laboratory values and by clinical markers. The investigators determined the difference, by treatment arm, in the reduction of uric acid level, alteration in renal function, length of hospital stay, and the total hospitalization cost in cancer patients with laboratory values or clinical markers and hyperuricemia. The changes were calculated as the difference between the uric acid level at treatment initiation, as well as 2 days later.
The evaluable population included 26 patients who received rasburicase and 104 receiving allopurinol. The mean baseline uric acid levels were 11.4 mg/dL in the rasburicase group and 11.2 mg/dL in the allopurinol group.
The investigators determined that patients treated with rasburicase had significantly greater mean reductions in uric acid levels, intensive care unit lengths of stay, hospital lengths of stay, and total hospitalization costs per patient than those treated with allopurinol.
By the second day of treatment, the mean uric acid levels were significantly lower with rasburicase (2.7 mg/dL) compared with allopurinol (8.0 mg/dL; P <.001). Changes in potassium, phosphorus, and creatinine levels were comparable between the groups by the second day of treatment.
The mean total lengths of stay were 11.5 days with rasburicase and 16.5 days with allopurinol; the mean intensive care unit stays were 1.4 days and 3.9 days, respectively; and the mean total costs per patient for inpatient hospitalization were $35,065 and $54,103, respectively.
The mean total costs per percentage of uric acid reduction were $3915 with rasburicase and $16,907 with allopurinol (P <.001).
“Although the drug cost of rasburicase is higher than allopurinol, treatment with rasburicase in patients with laboratory values TLS and clinical markers TLS was more cost-effective, because it reduced length of stay and overall costs,” Dr Cairo concluded.
He suggested that future analyses of cost-effectiveness should consider differences in outpatient costs as well.
