New Form of Asparaginase Approved to Treat Acute Lymphoblastic LeukemiaOn November 18, the Food and Drug Administration (FDA) approved Erwinaze, an alternate form of asparaginase that is derived from the bacterium Erwinia chrysanthemi, to treat acute lymphoblastic leukemia (ALL) in patients who have become allergic (hypersensitive) to other forms of asparaginase derived from the bacterium Escherichia coli.
Asparaginase kills leukemia cells by breaking down the amino acid asparagine in the plasma. Asparagine depletion is selectively toxic to leukemia cells, which, unlike normal cells, cannot synthesize asparagine. The level of asparaginase activity is known to correlate with leukemia control and survival.
The FDA approval was based on the results of a single-arm trial involving 58 patients between the ages of 2 and 18 and a safety analysis of 574 patients between the ages of 1 and 66 who participated in a program to expand access to the drug. Patients in both studies had developed allergic reactions to asparaginase and pegaspargase, another modified form of asparaginase, both of which are derived from E. coli.
In the single-arm trial, the main outcome measure was the proportion of patients in whom a prespecified threshold level of asparaginase activity was maintained at 48 or 72 hours after dosing. All evaluable patients in the trial achieved this outcome.
Erwinaze is given as an injection three times per week. Side effects associated with Erwinaze treatment include serious allergic reactions, inflammation of the pancreas, high blood levels of liver enzymes, blood clotting, bleeding, nausea, vomiting, and high blood sugar.
Erwinaze has been designated as an orphan drug, a designation given to drugs for the treatment of diseases affecting fewer than 200,000 people in the United States.
NCI Cancer Bulletin for November 29, 2011 - National Cancer Institute