Long-term outcomes of adults with acute lymphoblastic leukemia after autologous or unrelated donor bone marrow transplantation: a comparative analysis by the National Marrow Donor Program and Center for International Blood and Marrow Transplant Research.

For adults with high-risk or recurrent ALL who lack a suitable sibling donor, the decision between autologous (Auto) and unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) is difficult due to variable risks of relapse and treatment-related mortality (TRM). We analysed data from two transplant registries to determine outcomes between Auto and URD HSCT for 260 adult ALL patients in first (CR1) or second (CR2) CR. All patients received a myeloablative conditioning regimen. The median follow-up was 77 (range 12-170) months. TRM at 1 year post transplant was significantly higher with URD HSCT; however, there were minimal differences in TRM according to disease status. Relapse was higher with Auto HSCT and was increased in patients transplanted in CR2. Five-year leukemia-free (37 vs 39%) and overall survival (OS) rates (38 vs 39%) were similar for Auto HSCT vs URD HSCT in CR1. There were trends favoring URD HSCT in CR2. The long-term follow-up in this analysis demonstrated that either Auto or URD HSCT could result in long-term leukaemia-free survival and OS for adult ALL patients. The optimal time (CR1 vs CR2) and technique to perform HSCT remains an important clinical question for adult ALL patients.

Comparison of non-myeloablative conditioning regimens for lymphoproliferative disorders.

Hematopoietic cell transplantation (HCT) with non-myeloablative (NMA) conditioning for lymphoproliferative diseases (LD) includes fludarabine with and without low-dose TBI. Transplant outcomes were compared among patients aged ⩾40 years with LD who received a HCT with TBI (N=382) or no-TBI (N=515) NMA from 2001 to 2011. The groups were comparable except for donor, graft, prophylaxis for GVHD, disease status and year of HCT. Cumulative incidences of grades II-IV GVHD at 100 days were 29% and 20% (P=0.001) and of chronic GVHD at 1 year were 54% and 44% (P=0.004) for TBI and no-TBI, respectively. Multivariate analysis of progression/relapse, treatment failure and mortality showed no outcome differences by conditioning. Full donor chimerism at day 100 was observed in 82% vs 64% in the TBI and no-TBI groups, respectively (P=0.006). Subsets of the four most common conditioning/GVHD prophylaxis combinations demonstrated higher rates of grades II-IV acute (P<0.001) and chronic GVHD (P<0.001) among recipients of TBI-mycophenolate mofetil (MMF) compared with other combinations. TBI-based NMA conditioning induces faster full donor chimerism, but overall survival outcomes are comparable to no-TBI regimens. Combinations of TBI and MMF are associated with higher rates of GVHD without impact on survival outcomes in patients with LD.

Primary graft failure after myeloablative allogeneic hematopoietic cell transplantation for hematologic malignancies.

Clinical outcomes after primary graft failure (PGF) remain poor. Here we present a large retrospective analysis (n=23,272) which investigates means to prevent PGF and early detection of patients at high risk. In patients with hematologic malignancies, who underwent their first myeloablative allogeneic hematopoietic cell transplantation, PGF was reported in 1278 (5.5%), and there was a marked difference in PGFs using peripheral blood stem cell compared with bone marrow grafts (2.5 vs 7.3%; P<0.001). A fourfold increase of PGF was observed in myeloproliferative disorders compared with acute leukemia (P<0.001). Other risk factors for PGF included recipient age <30, HLA mismatch, male recipients of female donor grafts, ABO incompatibility, busulfan/cyclophosphamide conditioning and cryopreservation. In bone marrow transplants, total nucleated cell doses ⩽2.4 × 10(8) per kg were associated with PGF (odds ratio 1.39; P<0.001). The use of tacrolimus-based immunosuppression and granulocyte colony-stimulating factor were associated with decreased PGF risk. These data, allow clinicians to do more informed choices with respect to graft source, donor selection, conditioning and immunosuppressive regimens to reduce the risk of PGF. Moreover, a novel risk score determined on day 21 post transplant may provide the rationale for an early request for additional hematopoietic stem cells.