busulfan + cyclosporine + fludarabine + mycophenolate mofetil

This is a combination drug regimen used in hematopoietic stem cell transplantation (HSCT). The combination includes busulfan (an alkylating agent), cyclosporine (a calcineurin inhibitor), fludarabine (a purine nucleoside analog), and mycophenolate mofetil (an immunosuppressant). This regimen is primarily used as a reduced-intensity conditioning (RIC) regimen before stem cell transplantation, with cyclosporine and mycophenolate mofetil specifically serving as prophylaxis against graft-versus-host disease (GVHD). The combination is used in patients with various hematologic malignancies receiving allogeneic transplantation, particularly from unrelated donors.