Double Reduced-Intensity Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Study from the SFGM-TC

The purpose of this paper is to describe the outcome of patients who underwent double allogeneic hematopoietic stem cell transplantation (AHSCT) with reduced-intensity conditioning regimens (RIC). Forty-five patients who received double RIC-AHSCT between 1997 and 2006 were retrospectively studied. The predominant diagnosis was acute myeloid leukemia (AML) (n = 17). Other diagnoses were aplasic anemia (AA) (n = 5), myelodysplasic disorder (n = 5), acute lymphoblastic leukemia (ALL) (n = 4), chronic myelomonocytic leukemia (CML) (n = 3), myeloma (n = 3), non-Hodgkin lymphoma (NHL) (n = 3), chronic lymphocytic leukemia (CLL) (n = 2), Hodgkin's disease (HD) (n = 2), and chronic myelomonocytic leukemia (n = 1). Main indications for RIC-AHSCT 2 were relapse (n = 25, 56%) and early (n = 8, 18%) or late (n = 12, 26%) graft failure. Median delays to reach a neutrophil count of 0.5 × 109 /L and platelet counts of 50 × 109 /L were significantly smaller after the second AHSCT. Among 25 patients who relapsed after RIC-AHSCT 1, 14 patients (56%) presented a response improvement after RIC-AHSCT 2. In this group, 9 patients sustained a complete response and 5 patients a partial response. Moreover, among the 20 patients who had early or late graft failure following RIC-AHSCT 1, 9 (45%) finally reached an engraftment. Disease-free survival (DFS) was significantly improved after RIC-AHSCT 2. Thirteen patients (28%) died of transplant-related mortality (TRM) at a median delay of 69 days (range: 0-451) after RIC-AHSCT 2. Double RIC-AHSCT is a feasible procedure that allows a response or engraftment not observed after RIC-AHSCT 1. The main indication is relapse. However, TRM remains high.