[Bortezomib plus dexamethasone treatment followed by reduced-intensity allogeneic stem cell transplantation for multiple myeloma refractory to high-dose chemotherapy with autologous transplantation].

We present two long-term survivors after allogeneic transplantation with reduced-intensity conditioning regimen following relapse after autologous stem cell transplantation (ASCT) for multiple myeloma (MM). The first case was a 47-year-old male with IgG MM treated with 2 courses of high-dose melphalan along with ASCT and thalidomide, resulting in a minimal response. He then received 2 courses of bortezomib plus dexamethasone (BD) regimen, which was discontinued due to peripheral neuropathy. Allogeneic peripheral stem cell transplantation (PBSCT) from a sibling donor was performed after pretreatment with fludarabin (125 mg/m(2)) and melphalan (100 mg/m(2)). Engraftment was observed on day 11 and monoclonal IgG had disappeared 5 months after transplantation. The patient has been in complete remission for more than two and a half years with moderate chronic graft-versus-host disease (GVHD). The second case was a 51-year-old male who relapsed after ASCT for IgA MM. After 3 courses of BD treatment, irradiation to lumbar plasmacytoma, and thalidomide therapy, he received allogeneic PBSCT from a related donor after the same reduced intensity conditioning as performed in case 1. A complete response was observed 6 months after PBSCT. The patient has remained relapse-free for two years without GVHD. BD treatment followed by allogeneic stem cell transplantation with reduced intensity conditioning is supposed to be one of the most powerful strategies for patients showing relapse after ASCT.