busulfan + cyclophosphamide + horse anti-thymocyte globulin

This is a combination conditioning regimen used primarily before allogeneic hematopoietic stem cell transplantation (HSCT), especially in patients with severe aplastic anemia or certain hematologic malignancies. The regimen consists of three agents: - **Busulfan** is an alkylating agent that causes DNA cross-linking and cell death, particularly affecting rapidly dividing cells such as hematopoietic progenitors. - **Cyclophosphamide** is another alkylating agent that suppresses the immune system and further ablates bone marrow. - **Horse anti-thymocyte globulin (ATG)** is a polyclonal antibody preparation derived from horses immunized with human thymocytes; it depletes T lymphocytes by targeting multiple surface antigens, providing additional immunosuppression to prevent graft rejection and reduce the risk of graft-versus-host disease (GVHD). This combination aims to eradicate host hematopoiesis, provide sufficient immunosuppression for engraftment of donor cells, and minimize the risk of both rejection and GVHD. It is most commonly used in matched sibling donor transplants for severe aplastic anemia but may also be considered in other settings where intensive myeloablation and immunosuppression are required[4][5][1].

Brand names

AtgamBusulfexCytoxan

Other names

busulfan + cyclophosphamide + horse ATGBuCy + horse ATGBuCy-ATG (horse)busulfan/cyclophosphamide/horse antithymocyte globulin