ONCASPAR, the ENZON PHARMACEUTICALS, INC. trademark for pegaspargase, is a modified version of the enzyme L-asparaginase. It is an oncolytic agent used in combination chemotherapy for the treatment of patients with acute lymphoblastic leukemia who are hypersensitive to native forms of L-asparaginase (as described in CLINICAL PHARMACOLOGY).

The generic name for ONCASPAR^Ò is pegaspargase. The chemical name is monomethoxypolyethylene glycol succinimidyl L-asparaginase. L-asparaginase is modified by covalently conjugating units of monomethoxypolyethylene glycol (PEG), molecular weight of 5,000, to the enzyme, forming the active ingredient PEG-L-asparaginase. The L-asparaginase (L-asparagine amidohydrolase, type EC-2, EC 3.5.1.1) used in the manufacture of ONCASPAR^Ò is derived from Escherichia coli. ENZON purchases the enzyme L-asparaginase in bulk from Merck & Co., Inc., West Point, PA 19486, U.S. License Number 2. Merck & Co., Inc. supplies bulk L-asparaginase as a licensed intermediate for further manufacture by ENZON into PEG-L-asparaginase. Merck & Co., Inc. can only assume responsibility for the bulk intermediate supplied to ENZON.

ONCASPAR^Ò is supplied as an isotonic sterile solution in phosphate buffered saline, pH 7.3, for intramuscular or intravenous administration only. The solution is clear, colorless and contains no preservatives. It is supplied in 5 mL single-dose vials.

ONCASPAR^Ò activity is expressed in International Units (IU) according to the recommendation of the International Union of Biochemistry. One IU of L-asparaginase is defined as that amount of enzyme required to generate 1 mmol of ammonia per minute at pH 7.3 and 37°C.

Each milliliter of ONCASPAR^Ò contains:

PEG-L-asparaginase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 IU ± 20%
Monobasic sodium phosphate, USP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.20 mg ± 5%
Dibasic sodium phosphate, USP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.58 mg ± 5%
Sodium chloride, USP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.50 mg ± 5%
Water for injection, USP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . qs to 1.0 mL

The specific activity of ONCASPAR^Ò is at least 85 IU per milligram protein.

Bookmark this page: