PD-1 antibody + chidamide + lenalidomide + etoposide

This is a combination regimen consisting of a PD-1 antibody (commonly tislelizumab), chidamide, lenalidomide, and etoposide. It is being investigated primarily for the treatment of relapsed or refractory extranodal natural killer/T-cell lymphoma, nasal type (r/r-ENKTL). The regimen leverages multiple mechanisms: - **PD-1 antibody** (e.g., tislelizumab) acts as an immune checkpoint inhibitor by blocking the programmed death 1 receptor on T cells, thereby enhancing anti-tumor immune responses. - **Chidamide** is a selective histone deacetylase inhibitor that modulates gene expression and can induce tumor cell apoptosis while also enhancing cytotoxic T cell and NK cell activity. - **Lenalidomide** is an immunomodulatory agent that augments immune-mediated anti-tumor effects and has direct anti-proliferative properties. - **Etoposide** is a chemotherapeutic agent that inhibits topoisomerase II, leading to DNA damage in rapidly dividing cells. Clinical studies have shown promising response rates with this combination in r/r ENKTL patients who have failed prior therapies. The safety profile includes manageable hematologic toxicities such as leukopenia and anemia[6][9][2].