Dose Dense Re-challenge of High Dose Methotrexate With Glucarpidase for Relapsed Primary Central Nervous System Lymphoma

Glucarpidase (CPG2) Dose: 2000 U (2 vials of 1000 U per dose) 5 minutes-intravenous administration 24 hours after each Methotrexate infusion (i.e. 6 times in the whole protocol)

MTX will be administred 6 times during the protocol, at a variable interval of 8, 6 or 5 days. It will be administrated in a 2 to 3-hour IV infusion, at the dose of 3.5 g/m2 (body surface area capped at 2 m2). Each MTX administration will be preceded by a prehydration and will be followed by a posthydration