Comparison of mycophenolate mofetil and calcineurin inhibitor versus calcineurin inhibitor-based graft-versus-host-disease prophylaxis for matched unrelated donor transplant in acute myeloid leukemia. A study from the ALWP of the EBMT.

The association of Cyclosporine A (CsA) and mycophenolate mofetil (MMF) has increased in the setting of reduced intensity conditioning (RIC). Nevertheless, the use of CsA or CsA+MMF has not been reported in a large and uniform cohort. We analyzed 497 patients with acute myeloid leukemia in complete remission (CR) who underwent matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT). All patients received a fludarabine busulfan RIC regimen and anti-thymocyte globulin (ATG) with either CsA alone or in combination with MMF. The cumulative incidence (CI) of grade II-IV acute GvHD was 27% (95% CI 21-33%) for CsA and 33% (95% CI 27-38%) for CsA+MMF (p = 0.25). The 2-year CI of chronic GvHD was 38% (95% CI 31-45%) and 33% (95% CI 28-39%) for the CsA and the CsA+MMF group, respectively (p = 0.26). On multivariate analysis, no statistically significant differences with respect to relapse incidence (RI), non-relapse mortality (NRM), leukemia-free survival (LFS), overall survival (OS), acute and chronic GvHD were found between the two groups, also when conducting a subgroup analysis in peripheral blood stem cells (PBSC) recipients. Our results support the importance of randomized trial to identify patients who could benefit from the addition of MMF in MUD HSCT.