PURPOSE: We studied the efficacy and safety of bortezomib (BOR) for treatment of 
multiple myeloma in comparison with thalidomide (THAL) by reference to adverse 
events, and searched for laboratory markers that could be used for 
prognostication of patients.
METHODS: Biochemical data of patients receiving BOR and THAL for treatment of 
multiple myeloma at the Japanese Red Cross Narita Hospital were investigated 
retrospectively, after obtaining Institutional Review Board approval. Judgment 
of curative effects complied with the effects criteria of the International 
Myeloma Working Group (IMWG).
RESULTS: BOR showed a higher rate of effectiveness than THAL for refractory 
multiple myeloma, and its effects were rapid. BOR treatment prolonged the 
survival time of THAL-resistant patients. The efficacy of BOR was unrelated to 
patient age, the number of previous therapeutic regimens, or the disease period. 
After medication with BOR, patients in whom it had been effective tended to show 
an increase of the serum alkaline phosphatase (ALP) level. Thrombocytopenia 
(86.2%) and leucopenia (69.0%) were observed at high frequencies, but no 
previously unreported adverse events or fatalities were associated with BOR 
therapy.
CONCLUSION: It is suggested that BOR has therapeutic efficacy for multiple 
myeloma as a first-line medical treatment and/or for patients with THAL 
resistance, and can improve prognosis and survival. Since serum ALP elevation 
was observed in many patients for whom BOR was effective, this may be a 
predictor of BOR efficacy.