Dose Adjustment Helps Obtain Better Outcomes in Multiple Myeloma Patients with Bortezomib, Melphalan, and Prednisolone (VMP) Treatment

Objective: Multiple myeloma (MM) has a better survival outcome because of the development of drugs. However, equivalent outcomes cannot be expected from the same drug. Therefore, how the treatment schedule is managed is important. We analyzed VMP (bortezomib, melphalan, and prednisolone) data to determine an effective treatment strategy. Materials and Methods: We collected the data of 59 patients who were newly diagnosed with MM from January 2012 to April 2017 using electronic medical records. We analyzed baseline characteristics, responses, dose reductions, and survival. Results: The overall response rate was 86.5% [complete response (CR): 32.2%, very good partial response (VGPR): 37.3%]. The median progression-free survival was 33.6 months and the 5-year overall survival rate was 70%. There were significant better progression-free survival outcomes between CR and non-CR for each of the 4 cycles. Of the four patients who achieved CR after the first cycle, none have had disease progression as of yet. We divided patients into two groups according to the median dose (52.1 mg/m(2)) and we found no differences between the high-dose and low-dose groups. About 78% of patients completed 9-cycle schedules and 84% patients experienced dose reduction, mostly for reasons of non-hematologic toxicities. Conclusion: Active dose reduction helped to continue treatment and it increased the opportunity to be exposed to drugs. In the end, it resulted in improved outcome.