This trial studies the effect of pegloticase in reducing uric acid levels in patients with hyperuricemia (high blood levels of uric acid) caused by tumor lysis syndrome. Tumor lysis syndrome occurs when the breakdown products of cancer cells, such as uric acid, enter the blood stream. High levels of uric acid in blood may cause kidney damage and reduce kidney function. The goal of this trial is to learn if pegloticase may lower uric acid levels in blood when given to cancer patients with hyperuricemia caused by tumor lysis syndrome.

PRIMARY OBJECTIVE:

I. To collect preliminary data on the effectiveness of a single dose of pegloticase in lowering serum uric acid levels to less than 6.0 mg/dl within 24 hours in patients with hyperuricemia in the setting of tumor lysis syndrome.

SECONDARY OBJECTIVES:

I. To assess the effect of pegloticase on renal function in patients with hyperuricemia in the setting of tumor lysis syndrome as measured by changes in serum creatinine/estimated glomerular filtration rate (eGFR) and urine output.

II. To estimate the rate of renal replacement therapy initiation for acute kidney injury secondary to tumor lysis syndrome among patients treated with pegloticase.

OUTLINE:

Patients receive pegloticase intravenously (IV) over 120 minutes. Patients whose serum uric acid does not drop below 6 mg/dL within 24 hours receive a second dose of pegloticase IV over 120 minutes on day 2. Patients whose serum uric acid does not drop below 6 mg/dL after two doses of pegloticase receive standard of care rasburicase IV once daily (QD) for 5 days.

Inclusion Criteria:

For inclusion in the study, patients should fulfill the following criteria:

1. Signed informed consent prior to any study specific procedures (patient or caregiver)
2. Male or female 18 years of age or older
3. In the investigator's opinion, expected survival of at least 1 month
4. Deemed stable by the investigator
5. Serum Uric Acid ≥ 6 mg/dL
6. Risk for tumor lysis syndrome based on the MD Anderson TLS risk score

Exclusion Criteria:

Patients will be ineligible for study enrollment if any of the following exclusion criteria are fulfilled:

1. Inability or refusal to give informed consent (patient or caregiver)
2. Subject unwilling to take study medication
3. Known allergy to uricase
4. Pregnant
5. Breastfeeding
6. Known glucose-6-phosphate dehydrogenase (G6PD) deficiency
7. Transfusion in last 7 days (as this interferes with G6PD test), with the exception of platelet transfusions.
8. Has received rasburicase during current admission.(Can be considered i24 hours after last Rasburicase administered, current or previous admission)