[Prediction of treatment efficacy by the M-protein reduction rate after the first cycle of VAD therapy for multiple myeloma].

In recent years, novel drugs for multiple myeloma such as bortezomib and thalidomide have been shown to be effective. However, in Japan, these drugs are indicated only for patients with relapsed or refractory multiple myeloma. There are no established criteria for the definition of refractory cases, and it is often difficult to determine when treatment methods should be changed for those cases.