Glucarpidase

Glucarpidase was approved by the FDA in January 2012 to reduce toxic plasma methotrexate concentrations (above 1 micromole per litre) in adults and children with delayed methotrexate clearance due to impaired renal function, on pooled single-arm studies in which a single 50 units/kg dose lowered methotrexate by more than 95% within 15 minutes in almost all patients. It does not replace leucovorin, which must continue (given at least two hours apart because glucarpidase also cleaves leucovorin), and it is not for patients with expected clearance. In the EU it is available through named-patient supply rather than a central authorisation. Marketed by BTG, now SERB.