The US Food and Drug Administration (FDA) has approved Voraxaze (glucarpidase) to treat patients with toxic levels of methotrexate in their blood due to kidney failure.
Methotrexate is a commonly used cancer chemotherapy drug normally eliminated from the body by the kidneys. However, patients receiving high doses of methotrexate may develop kidney failure.
Voraxaze is an enzyme that rapidly reduces methotrexate levels by breaking the chemotherapy drug down to a form that can be eliminated from the body. Voraxaze is administered directly into a patient’s vein (intravenously).
“Prolonged exposure to high levels of methotrexate can result in kidney and liver damage, severe mouth sores, damage to the lining of the intestine, skin rashes, and death due to low blood counts,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Voraxaze is an important new treatment option for cancer patients aimed at preventing these toxicities associated with sustained high levels of methotrexate.”
Voraxaze has an orphan drug designation, given to therapies indicated for rare or specific disease populations.
A single clinical study of 22 patients evaluated the effectiveness of Voraxaze. All patients received Voraxaze treatment. The study considered treatment a success if the methotrexate level fell below a critical level within 15 minutes and stayed below the critical level for eight days. Ten of the 22 patients achieved this standard. Although not all patients experienced this result, Voraxaze eliminated 95 percent of the methotrexate in all patients.
A separate clinical study evaluated the safety of Voraxaze in 290 patients experiencing problems clearing methotrexate from their blood.
The most common side effects observed in greater than one percent of patients in the clinical study were low blood pressure (hypotension), headache, nausea, vomiting, flushing, and abnormal sensation (paraesthesia).
Voraxaze is marketed by BTG International Inc., West Conshohocken, Pennsylvania.