FluTreo, FluMel, or BuCy conditioning for older AML or MDS patients
Beelen DW, Iacobelli S, Koster L, et al. Fludarabine-Treosulfan Versus Fludarabine-Melphalan or Busulfan-Cyclophosphamide Conditioning in Older AML or MDS Patients — A Clinical Trial to Registry Data Comparison. Bone Marrow Transplantation. 2024; (doi: 10.1038/s41409-024-02241-2).
The combination of fludarabine and treosulfan 30 g/m2 (FluTreo) is gaining acceptance as reduced-toxicity conditioning (RTC) for older adults with acute myeloid leukemia or myelodysplastic syndrome (MDS) who are preparing for allogeneic hematopoietic cell transplantation. RTC regimens pair the lower organ toxicities of reduced-intensity conditioning with the powerful anti-tumor properties of myeloablative conditioning. A recent retrospective analysis focused on 252 patients aged 50-70 years who received FluTreo. Outcomes were compared with those of propensity-score matched patients whose conditioning consisted of fludarabine plus melphalan 140 mg/m2 IV (FluMel), an intermediate conditioning protocol, or busulfan 12.8 mg/kg IV plus cyclophosphamide 120 mg/kg (BuCy), a high-intensity option. At 2-year follow-up, researchers documented no significant difference in the rate of relapse between the three exposures, although non-relapse mortality (NRM) over that period was lower with FluTreo than with the comparator regimens. FluTreo and FluMel achieved similar levels of antileukemic efficacy, but FluTreo achieved better tolerability in older AML patients in complete remission. Both FluTreo and FluMel generated comparable outcomes in older MDS patients. Compared with BuCy, FluTreo correlated to better 2-year overall survival, primarily due to the lower rate of NRM. The study data demonstrate FluTreo as an appropriate RTC regimen, with similar efficacy as intermediate or even high-intensity conditioning in older AML and MDS patients.