Camrelizumab for Patients with Recurrent Primary Central Nervous System Lymphoma (PCNSL)

This study is testing camrelizumab — an immunotherapy drug that helps the immune system fight cancer — in patients whose primary central nervous system (CNS) lymphoma has come back after initial treatment. CNS lymphoma is a rare cancer that starts in the brain or spinal cord. **You may be eligible if...** - You were originally diagnosed with primary large B-cell lymphoma of the brain or central nervous system, confirmed by biopsy - Your cancer has returned (relapsed) after first-line treatment with methotrexate-based chemotherapy - A brain MRI shows measurable disease - You are over 18 years old - Your organs (blood, heart, liver, kidney) are functioning adequately - You have a Karnofsky performance score of at least 50% (able to manage some self-care) **You may NOT be eligible if...** - You have not had prior treatment with methotrexate - Your organs are not functioning at adequate levels - Your general health status is too poor to participate Talk to your doctor to see if this trial is right for you.