Testing the Addition of Lenalidomide and Nivolumab to the Usual Treatment for Primary CNS Lymphoma

This phase I trial tests the safety, side effects, best dose and effectiveness of lenalidomide when added to nivolumab and the usual drugs (rituximab and methotrexate) in patients with primary central nervous system (CNS) lymphoma. Lenalidomide may stop or slow primary CNS lymphoma by blocking the growth of new blood vessels necessary for tumor growth. Immunotherapy with monoclonal antibodies, such as nivolumab, may help the body's immune system attack the cancer, and may interfere with the ability of cancer cells to grow and spread. Rituximab is a monoclonal antibody that may interfere with the ability of cancer cells to grow and spread. Methotrexate is frequently combined with other chemotherapy agents to improve response. This study may help increase the understanding of lenalidomide and nivolumab use in primary CNS lymphoma treatment. In addition, it may help researchers see whether the control of CNS lymphoma can be extended by using these study drugs as maintenance (prolonged therapy) after control is achieved with the initial chemotherapy regimen (induction).