Study of Epcoritamab in R/R Primary Diffuse Large B-cell Lymphoma of the CNS Treated With Lenalidomide and Rituximab

This study tests a drug called epcoritamab combined with lenalidomide and rituximab for people with a rare type of brain lymphoma called primary CNS diffuse large B-cell lymphoma (PCNSL) or primary vitreoretinal lymphoma (PVRL) — lymphomas that occur in the brain/spinal cord or in the eye — that have come back after prior treatment. **You may be eligible if...** - You are 18 years or older - You have confirmed PCNSL or PVRL that has relapsed or is refractory (not responding to treatment) - You have previously received high-dose methotrexate (a standard first-line treatment) - You have measurable disease visible on brain MRI - You are in adequate health (ECOG performance status 0–2) - You can swallow capsules **You may NOT be eligible if...** - You have severe blood count problems - You have significant liver or kidney dysfunction - You are pregnant or breastfeeding - You have active infections such as HIV, hepatitis B, or hepatitis C Talk to your doctor to see if this trial is right for you.