Sequential Trial on Reduced Intensity Conditioning (RIC) Allogeneic Transplantation

The aim of the current study is to improve the outcome of patients with hematologic malignancies (in a phase I trial) and more specifically multiple myeloma (in a phase II trial) by 2 interventions: reduce the risk of graft-versus-host disease (GVHD) and improve the efficacy of the procedure decreasing the risk of relapses after transplant. Currently, the standard approach used in most centers to prevent graft-versus-host disease after allogeneic transplantation is based on the combination of a calcineurin inhibitor (cyclosporine or tacrolimus) plus a short course of methotrexate. Unfortunately, this strategy is far from ideal, since the risk of acute GVHD is in the range of 30-40% among patients receiving a matched related donor transplantation and even higher among patients receiving transplantation from an unrelated donor while the incidence of chronic GVHD is 60-70% among patients receiving peripheral blood progenitor cells from either a related or unrelated donor. As far as the patients with multiple myeloma (MM) is concerned, although the development of new drugs has markedly changed the outcome and management of these patients, allogeneic transplantation so far appears to be the only curative option, especially among those patients relapsing after first line treatment. Nevertheless, still new strategies within the allogeneic transplant setting are needed to improve its results. Relapses may occur either extramedullary (very common in this setting) or systemic. In order to reduce the risk of systemic relapses the investigators will use maintenance therapy with Lenalidomide (Len) which, together with bortezomib (Bz) should contribute to eradicate minimal residual disease (MRD). In case the patient do not obtain complete remission or near complete remission after transplant, in addition to the maintenance therapy, the investigators will use four intensification cycles with VRD (Bz-Len-Dexamethasone). In summary, the goal is to optimize the efficacy of alloge