obutinib + decitabine + rituximab + compound cyclophosphamide + prednisone

This is a combination regimen consisting of five agents: - **Obutinib** is a Bruton's tyrosine kinase (BTK) inhibitor, similar in class to ibrutinib, and is used as an antineoplastic agent primarily for B-cell malignancies. It inhibits BTK, thereby blocking B-cell receptor signaling and reducing proliferation and survival of malignant B cells. - **Decitabine** is a hypomethylating agent that incorporates into DNA and inhibits DNA methyltransferase, leading to hypomethylation of DNA and reactivation of silenced genes. It is mainly used in the treatment of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). - **Rituximab** is a monoclonal antibody targeting CD20 on B lymphocytes, resulting in cell lysis through complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity, and direct apoptosis. - **Compound cyclophosphamide** refers to cyclophosphamide or its formulations; it acts as an alkylating agent that crosslinks DNA strands leading to inhibition of DNA replication and cell death. Cyclophosphamide is widely used in various chemotherapy regimens for hematologic malignancies. - **Prednisone** is a synthetic glucocorticoid with anti-inflammatory and immunosuppressive properties; it induces apoptosis in certain cancerous lymphoid cells. This combination targets multiple pathways involved in the growth, survival, epigenetic regulation, immune evasion, and proliferation of malignant hematopoietic cells. Such regimens are typically investigated or utilized for aggressive lymphomas or leukemias where multi-agent therapy may improve outcomes by attacking cancer through different mechanisms.