Early response to bortezomib combined chemotherapy can help predict survival in patients with multiple myeloma who are ineligible for stem cell transplantation.

Novel agents to treat multiple myeloma (MM) have increased complete respone (CR) rates compared with conventional chemotherapy, and the quality of the response to treatment has been correlated with survival. The purpose of our study was to show how of early response to bortezomib combined chemotherapy influences survival in patients with newly diagnosed MM who are ineligible for stem cell transplantation. We assessed patient responses to at least four cycles of bortezomib using the International Myeloma Working Group response criteria. The endpoints were comparisons of progression free survival (PFS) and overall survival (OS) between early good response group (A group) and poor response group (B group). We retrospectively analyzed data from 129 patients registered by the Korean Multiple Myeloma Working Party, a nationwide registration of MM patients. The 3 yr PFS for the A and B groups was 55.6% and 18.4%, respectively (P < 0.001). The 3 yr OS for the A and B groups was 65.3% and 52.9%, respectively (P = 0.078). The early response to at least four cycle of bortezomib before next chemotherapy may help predict PFS in patients with MM who are ineligible stem cell transplantation.