rituximab + methotrexate + vincristine + procarbazine + lenalidomide

This is a multi-agent combination chemotherapy and immunotherapy regimen composed of five drugs: - **Rituximab** is a monoclonal antibody targeting CD20 on B cells, leading to their depletion. - **Methotrexate** is an antimetabolite that inhibits dihydrofolate reductase, blocking DNA synthesis. - **Vincristine** is a vinca alkaloid that disrupts microtubule formation, inhibiting mitosis. - **Procarbazine** is an alkylating agent causing DNA damage and cell death. - **Lenalidomide** is an immunomodulatory drug with antiangiogenic and direct antineoplastic effects. This combination has been explored in the treatment of primary central nervous system lymphoma (PCNSL) and related lymphomas. The R-MPV backbone (rituximab, methotrexate, procarbazine, vincristine) has established efficacy in PCNSL[1][2][3][5]. Lenalidomide has been investigated as an adjunct to enhance response rates or as maintenance therapy[6][8]. The regimen leverages multiple mechanisms—targeted B-cell depletion, cytotoxicity via DNA damage or mitotic arrest, and immune modulation—to maximize anti-tumor activity.