Kinetics Of Response To Bortezomib/Thalidomide/Dexamethasone (Vtd) In Multiple Myeloma: Implications For The Choice And Design Of Pretransplantation Induction Regimens

Background: Autologous stem-cell transplantation (ASCT) is the standard of care for younger patients with multiple myeloma (MM). The degree of tumor reduction after ASCT is the crucial factor associated with a prolonged PFS and OS, being the M-protein decrease at the time of transplant the most important predictor of residual disease after ASCT. While there is an agreement that bortezomib and dexamethasone associated to a third drug is the induction of choice, which should be the third drug (thalidomide, lenalidomide, doxorubicin or cyclophosphamide) and the optimal number of cycles remain unknown. The results of phase 3 PETHEMA study GEM05menos65 showing a CR rate of 35% increasing overtime during the 6 induction cycles of VTD (Rosiñol et al, Blood 2012) prompted us to study the kinetics of response to VTD and TD in this study and in similar historic data with the VD regimen in phase 2 PETHEMA VELCA/DEXA trial (Rosiñol et al, JCO 2007).