Transplant-Related Mortality in Patients ≥50 Years of Age Is No Lower after Transplantation from Young Fully Matched Unrelated Donors (MUD) Than from Matched Siblings When All Patients Are Given the FLUBUP Regimen with Thymoglobulin.

Abstract

There are reports indicating that older patients (pts) may have better outcomes after stem cell transplantation (SCT) from young fully matched unrelated donors (MUD) than from matched siblings (MRD) perhaps because of donor age. In some of these studies MUD and MRD recipients may have been treated differently, for example with more intense GVHD prophyaxis for MUD SCT such as antithymocyte globulin (ATG). We have compared outcomes of SCT pts receiving myeloablative fludarabine & busulfan based conditioning (FLUBUP) between 05/99 and 05/05. Only 10/10 (HLA–A, −B, C, DR & DQ) matched SCT were considered. Recipients of MRD SCT were ≥50 years old, MUD SCT recipients were unselected for age but their donors were ≤30 years old. All pts received fludarabine 50mg/m2 on days −6 to −2 and IV busulfan (Busulfex, PDL Pharma) at a myeloablative dose of 3.2 mg/kg once daily days −5 to −2 inclusive (FLUBUP) +/− TBI 200cGy x 2 on day −1 or 0. Prophylaxis for GVHD was cyclosporine A, methotrexate with folinic acid and Thymoglobulin (Genzyme) 4.5 mg/kg in divided doses over 3 consecutive days pretransplant finishing D0.[table 1]These data demonstrate that TRM for older SCT pts given the FLUBUP regimen with ATG is similar to that for adults in general transplanted from young MUD. When using these protocols in older pts there is usually no justification for the expense and inconvenience of using a young MUD in preference to a matched sibling.Patient, donor & SCT characteristics and outcomesUnrelatedRelatedpNumber4163Patient age median (range)44 (16–61)55 (50–65)<0.0001Donor age median (range)24 (19–30)52 (37–71)<0.0001Low risk (Acute leukemia CR1/2, CML CP1)22 (54%)14 (22%)0.0015CMV+ve recipient or donor31 (76%)53 (84%)nsFemale to male SCT8 (20%)18 (29%)nsBlood cells20 (49%)56 (89%)<0.0001CD 34+ cell dose x 10e6 median (range)5.35 (0.91–15.47)4.23 (0.83–13.52)0.08TBI (not TRM risk factor)19 (46%)10 (16%)0.0014Acute GVHD II–IV21±7%16±5%nsAcute GVHD III–IV10±5%5±3%nsChronic GVHD64±7%61±9%nsPts≥50 TRM *26±15% (n = 12)16±5%nsLow risk TRM5±5%0%nsHigh risk TRM31±12%23±7%nsBCT TRM10±7%19±6%nsAll pts TRM16±6%16±5%ns* at 5 years