High response rate and improved graft-versus-host disease following bortezomib as salvage therapy after reduced intensity conditioning allogeneic stem cell transplantation for multiple myeloma.

We describe the results of 37 myeloma patients who received bortezomib following reduced intensity allogeneic stem cell transplantation (RIC-allo-SCT). Grade 1-2 peripheral neuropathy (35%), mild thrombocytopenia (24%) and fatigue (19%) were the most frequent adverse events, while there was no worsening of graft-vs-host disease symptoms. Twenty-seven patients (73%; 95% CI, 59-87%) achieved an objective response. With a median follow-up of 9 months from bortezomib initiation, the estimate of overall survival was 65% at 18 months while this was significantly higher (p=0.002) in the 27 patients achieving an objective response, suggesting that bortezomib is a safe and efficient option for myeloma patients after RIC-allo-SCT.