[Effective combination therapy of bortezomib and dexamethasone for two patients with refractory multiple myeloma].

We describe 2 cases of conventional therapy-resistant multiple myeloma (MM) that responded to bortezomib and dexamethasone therapy. Case 1: A 62-year-old woman with MM (IgG, kappa-type, stage IIIA) resistant to DMVM-IFN (dexamethasone, ranimustine, vincristine, melphalan, interferon-a), VAD (vincristine, doxorubicin, dexamethasone), high-dose melphalan with autologous peripheral blood stem cell transplantation (PBSCT) and thalidomide, received 2 courses of bortezomib treatment. In the first course, bortezomib alone was administered and then in the second course bortezomib was given in combination with dexamethasone. The patient's serum IgG level decreased from 8040 to 1020 mg/dl and the level of plasma cells in bone marrow was 1.2% after the treatments. Adverse reactions including rash, anemia, and thrombocytopenia occurred in the first course; however, they were milder in the second course combined with dexamethasone. Case 2: A 43-year-old man with MM (IgD, gamma-type, stage IIA) resistant to conventional and high-dose chemotherapy with PBSCT as well as thalidomide therapy, received treatment with bortezomib alone and then in combination with dexamethasone. His serum IgD level decreased from 2140 to 623 mg/dl. He suffered adverse reactions such as fatigue, anemia, and thrombocytopenia in the first course, which were relieved in the second course. These results indicate that the combination of bortezomib and dexamethasone is effective in the treatment of refractory MM and that dexamethasone can reduce the adverse reactions of bortezomib.