busulfan + cyclophosphamide + fludarabine + mycophenolate mofetil + rituximab + tacrolimus + thymoglobulin

This is a multi-agent combination regimen consisting of seven drugs—busulfan, cyclophosphamide, fludarabine, mycophenolate mofetil, rituximab, tacrolimus, and thymoglobulin. It is used as a conditioning and immunosuppressive protocol primarily in the context of hematopoietic stem cell transplantation (HSCT) for hematologic malignancies such as leukemia and lymphoma. The regimen combines alkylating agents (busulfan and cyclophosphamide), an antimetabolite (fludarabine), an immunosuppressant/antiproliferative agent (mycophenolate mofetil), a monoclonal antibody targeting CD20-positive B cells (rituximab), a calcineurin inhibitor (tacrolimus), and anti-thymocyte globulin for T-cell depletion. The combined mechanisms aim to eradicate malignant cells, suppress the immune system to prevent graft rejection or graft-versus-host disease (GVHD), and reduce relapse risk.