Elitek (Rasburicase) Immuno-Monitoring Study

Inclusion criteria:

1. Previous history of rasburicase exposure and history of administration of a repeat
(2nd) series of rasburicase injections (in the context of supportive care for
relapsing leukemia/lymphoma) and subsequent development of either a hypersensitivity
reaction (HSR) or loss of uricolytic activity (defined as failure to achieve uric
acid level of < or = 7.5 mg/dl measured 48 hours after the first rasburicase
injection).

1. A severe hypersensitivity reaction (NCI Grade 3, 4 or 5) is defined as:

Allergic reaction; allergy; anaphylactic shock; bronchospasm; bullous skin
eruption; dermatitis - exfoliative; drug hypersensitivity; dyspnea; hypotension;
hypoxia; rash; rash - erythematous; rash - maculopapular, urticaria;
pyrexia/fever; edema; chest discomfort; hypersensitivity (NOS); pharynx
discomfort; hoarseness; pharyngeal erythema; pruritus; erythema; localized
exfoliation; rash - papular; swelling ¿ face/facial; toxic skin eruption; hot
flush; flushing; rash - macular; rash - pruritic; pruritus - allergic.

2. Loss of uricolytic activity can be defined as:

- uric acid levels > 7.5 mg/dl measured 48 hours after the first rasburicase
injection¿, which is a time point coincident with administration of the
third dose of rasburicase (within that second course of treatment with this
agent).

2. Patients should have received at least 2 doses of rasburicase during the repeat (2nd)
administration in the event of loss or uricolytic activity. At least 1 dose of
rasburicase should be administered during the repeat (2nd) administration for
diagnosis of HSR.

Exclusion criteria:

1. Concomitant treatment with human IV immunoglobulin (IVIG)

2. Concomitant treatment with TNF-alpha antagonists/inhibitors, i.e. adalimumab,
infliximab, and etanercept

3. Concomitant treatment with Interferon-alpha (IFN-alpha)

4. Unwillingness or inability to comply with the requirements of the protocol.

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.