Bortezomib-Dexamethasone Re-Treatment At Biochemical Relapse Vs Observation In Relapsed/Refractory Multiple Myeloma Patients: Results Of A Phase Ii Multi-Center, Randomized Study

Background: The pattern of multiple myeloma (MM) relapses includes both biochemical relapses, characterized by the increase of monoclonal paraprotein in absence of organ dysfunction and CRAB symptoms, and clinical relapses, when the increase of monoclonal protein is associated with organ dysfunction. The International Myeloma Working Group (IMWG) recommends starting the subsequent treatment when either clinical relapse or a significant paraprotein increase occur (Rajkumar S. V. et al., Blood 2011 Feb 3; 1st ed.). To date, no data are available about the benefit of treatment at biochemical relapse rather than waiting for clinical relapse. Data from the RETRIEVE study suggested that re-treatment with bortezomib is safe and effective (Petrucci M. T. et al., Haematologica 2010; 95 (s2):152). Here we report the results of a phase II multi-center, randomized study that investigated the efficacy and safety of bortezomib re-treatment at biochemical relapse compared to observation until clinical relapse.