Pembrolizumab + Chemotherapy in Newly Diagnosed PCNSL

Humanized immunoglobin G4 monoclonal antibody, 4 mL vials, via intravenous infusion (into the vein) per protocol.

Anti-metabolite, 50 mL vials, via intravenous infusion per protocol.

Alkylating agent, 5, 20, 100, 140, 180, or 250 mg capsules, taken orally per protocol.

Anti-CD20 antibody, 10 or 50 mL single-use vials, via intravenous infusion per standard of care.