Allogeneic hematopoietic stem cell transplantation (HSCT) has been shown to improve the outcome of poor-risk AML and MDS in both younger and older patients. Reduced-intensity conditioning (RIC) regimen have partially abrogated the problem of regimen-related toxicity. However, graft-versus-host disease (GvHD) remains a major cause of non-relapse morbidity and mortality. Despite a strong graft versus leukemia (GvL) effect after allogeneic HSCT, the relapse rate after transplantation in poor-risk leukemia patients is still too high, necessitating new approaches to exploit GvL in a more optimized way. In addition, minimizing the GvHD reaction remains an important goal. One attractive strategy may be the administration of epigenetic therapy early after HSCT in order to optimize the GvL effect, to provide a direct anti-leukemic effect, and to control GvHD. Two preceding phase I/II studies have suggested that post-transplant administration of the histone deacetylase (HDAC) inhibitor panobinostat may be associated with a reduced relapse rate, while allowing for control of GvHD. Based on these two studies, the hypothesis of the present trial is that panobinostat can be an effective drug in preventing relapse by optimizing GvL in MDS and AML patients with high-risk features after HSCT, while at the same time reducing GvHD. It has been designed to test this hypothesis in a prospective randomized trial comparing maintenance with panobinostat interspersed with donor lymphocyte infusions (DLI) versus the standard approach of pre-emptive DLI alone in patients with poor-risk AML/MDS having favorably received an allogeneic HSCT followed by engraftment, donor chimerism and hematopoietic reconstitution.
Aim of this prospective randomized trial is to compare maintenance treatment with panobinostat interspersed with donor lymphocyte infusions (DLI) versus the standard approach of pre-emptive DLI alone in patients with poor-risk AML/MDS having favorably received an allogeneic HSCT followed by engraftment, donor chimerism and hematopoietic reconstitution.