fludarabine + amsacrine + cytarabine + busulfan

**Fludarabine + amsacrine + cytarabine + busulfan** (commonly known as **FLAMSA-Bu** or **FLAMSA-RIC**) is an academic, investigator-developed sequential chemotherapy conditioning regimen administered prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT). It is primarily utilized in patients with high-risk, relapsed, or refractory myeloid malignancies, such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The regimen is designed in two distinct phases: an initial intensive cytoreductive phase consisting of fludarabine, cytarabine, and amsacrine (the FLAMSA protocol) to rapidly reduce leukemic blast burden, followed by a reduced-intensity conditioning (RIC) phase utilizing the alkylating agent busulfan. Because all four components are widely available generic drugs, there is no single commercial developer or brand name associated with the combination. It has been evaluated in clinical trials such as the FIGARO trial and registry analyses by the European Society for Blood and Marrow Transplantation (EBMT).

Other names

FLAMSA-BuFLAMSA-Bu regimenFLAMSA-RICfludarabine/amsacrine/cytarabine-busulfan