[Conditioning regimen containing fludarabine instead of cyclophosphamide for haploidentical hematopoietic stem cell...

To explore the feasibility and safety of conditioning regimen containing fludarabine (Flud) for haploidentical hematopoietic stem cell transplantation (HSCT).

Preparative regimen containing Flud 40 mgxm(-2)xd(-1) on day -7 to -3 in place of cyclophosphamide (CTX) for haploidentical HSCT was given to 35 patients with hematologic malignancies (4 standard risk, 16 high risk, 15 relapse with no remission). All donors received rhG-CSF followed by HSC harvest. One patient received peripheral blood HSCT (PBSCT), one bone marrow transplantation (BMT), and the others BM combination with PBSCT. The regimen-associated side effect, engraftment, incidence of graft-versus-host disease (GVHD) and disease-free survival (DFS) probabilities were observed.

All patients achieved sustained, full donor-type engraftment. Thirty-four patients obtained primary durable engraftment, and 1 who rejected graft from his mother obtained successful durable engraftment after the second graft from his father. The cumulative incidence of grade III-IV acute GVHD and chronic GVHD was 12.1% and 31.7%, respectively. With a follow-up duration of 8-25 months, 6 patients were dead, in which 3 died of relapse, 2 of acute GVHD, 1 of fungal infection, none died of regimen-associated side effect. The other 29 patients remained alive and DFS probability was 79.7%.

Flud based conditioning regimens for haploidentical HSCT is safe and feasible, which reduces regimen-associated side effect, with no increasing the rate of relapse and infection, and decreases the incidence of aGVHD.