The U.S. Food and Drug Administration approved Erwinaze (asparaginase Erwinia chrysanthemi) to treat patients with acute lymphoblastic leukemia (ALL), who have developed an allergy (hypersensitivity) to E. coli derived asparaginase and pegapargase chemotherapy drugs used to treat ALL.
Acute lymphoblastic leukemia is a type of cancer in which the bone marrow makes too many lymphocytes, a type of white blood cell. White blood cells help the body fight infection and are formed in the bone marrow.
Erwinaze is injected directly into the muscle three times a week and works by breaking down one of the body’s protein building blocks (the amino acid, asparagine) that is present in the blood, and is necessary for the growth of all cells. Leukemia cells cannot produce this protein building block. When a patient is treated with Erwinaze the leukemia cells die. Normal human cells are able to make enough asparagine for their own needs through biosynthesis and will not be affected by treatment with Erwinaze.
“The approval of Erwinaze underscores the FDA’s commitment to the approval of drugs for conditions with limited patient populations with unmet medical needs using novel trial endpoints” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.
The safety and effectiveness of Erwinaze was evaluated in one clinical trial of 58 patients. Additional safety data was collected from the Erwinaze Master Treatment Protocol (EMTP), an expanded access program that enrolled 843 patients. Patients in both studies were unable to continue receiving pegaspargase or asparaginase derived from E. coli due to allergic reactions.
In the trial to support efficacy, the main outcome (endpoint) was the measurement of the proportion of patients with sustained asparaginase activity levels that correlate with better leukemia control and survival. All evaluable patients were shown to have maintained the pre-specified threshold for asparaginase activity at 48 or 72 hours after dosing.
Side effects associated with Erwinaze treatment include serious allergic reactions (anaphylaxis), inflammation of the pancreas (pancreatitis), high blood levels of liver enzymes (abnormal transaminases and bilirubin), blood clotting, bleeding (hemorrhage), nausea, vomiting and high blood sugar (hyperglycemia).
Prior to Erwinaze’s approval there were two asparagine specific enzyme products – Elspar (asparaginase injection) and Oncaspar (pegaspargase) – approved by FDA to treat patients with ALL. Both of these products are E. coli derived.
Erwinaze has been designated as an orphan drug, which identifies the disease as affecting fewer than 200,000 people in the U.S.
Erwinaze is manufactured by EUSA Pharma Inc. of Langhorne, Pa.
Date: November 18, 2011
Source: U.S. Food and Drug Administration