Study of Daratumumab in Multiple Myeloma (MM) Patients in >VGPR/MRD-positive

Aim of this study is to evaluate Daratumumab effect on MRD-positive patients with Multiple Myeloma (MM) who achieved \>VGPR after any therapy (ASCT, VMP, Rev-Dex). Daratumumab 16 mg/kg administered at weekly intervals for 8 weeks, then every 2 weeks for an additional 16 weeks, will be given to 50 MM patients who achieved a \>VGPR defined by monoclonal component disappearance in serum or urine, immunofixation positive/negative and MRD-positivity (by NGF). Free light chain (FLC) and CT/PET will be evaluated at time 0. NGF will be done on marrow aspirate at time 0, at 2 months and every 6 months for 2 years. If patients will be still MRD positive after 6 months of therapy , treatment will be continued up to 2 years. If MRD negative by NGF, the patients can stop the treatment.