A drug used to treat toxic levels of methotrexate (an anticancer drug) in the blood of patients with kidney problems. It is a bacterial enzyme that breaks down proteins and other substances, such as methotrexate. Carboxypeptidase-G2 may also help certain drugs kill cancer cells. It is a type of chemoprotective agent and a type of prodrug activator. Also called glucarpidase and Voraxaze.