IGNITE: Study of Tirabrutinib vs Rituximab/Temozolomide for Relapsed/Refractory Primary Central Nervous System Lymphoma (PCNSL)

This study (IGNITE) is comparing two treatments — tirabrutinib (a targeted pill) versus a chemotherapy combination (rituximab and temozolomide) — for people with primary central nervous system lymphoma (a rare blood cancer in the brain) that has come back after treatment. **You may be eligible if...** - You have been diagnosed with B-cell lymphoma that started in the brain or spinal fluid - Your lymphoma has come back or did not respond after at least one prior treatment containing high-dose methotrexate - You have at least one measurable tumor in the brain visible on MRI - Your overall health, kidney, liver, and bone marrow function are adequate **You may NOT be eligible if...** - Your lymphoma is not confirmed as B-cell type in the central nervous system - You have severe organ problems preventing treatment - You require systemic corticosteroids at high doses Talk to your doctor to see if this trial is right for you.