Bortezomib-Based Salvage Chemotherapy in Refractory/Relapsed Multiple Myeloma Patients: A Single Center Experience in Real Clinical Practice

Kim, Dong Hyun; Lee, Ji Hyun; Kim, Sung Hyun; Oh, Sung Yong; Lee, Suee; Moon, Sang Yi; Kim, Hyo Jin

Abstract

BACKGROUND/AIMS
Bortezomib-based chemotherapy has proven to be an effective salvage regimen for refractory/relapsed multiple myeloma patients in many clinical trials. However, few reports have shown the outcomes and adverse events of bortezomib-based salvage chemotherapy in clinical practice.
METHODS
From April 2006 to September 2011, 37 patients were retrospectively analyzed. A total of 19 patients received bortezomib therapy and 18 patients received bortezomib plus dexamethasone therapy.
RESULTS
The median follow-up duration was 18.13 months (range, 0.97-87.20 months). The median number of cycles administered was four (range, 1-13). The overall response rate by International Myeloma Working Group (IMWG) 2006 criteria was 64.9%, including six complete responses (16.2%). The median number of cycles to best response was three (95% confidence interval [CI], 1.36-4.64). Six patients achieved their best responses after four cycles of bortezomib therapy. The median time to progression and overall survival were 5.10 (95% CI 4.03-6.17), and 23.10 (95% CI, 9.24-36.96) months, respectively. The incidence of grade 3/4 neutropenia and thrombocytopenia was 29.7% and 64.9%, respectively. A total of 27.0% patients experienced grade 3 peripheral neuropathy. Herpes zoster developed in 11 patients (29.7%). Treatment was stopped in 22 patients (59.5%) due to adverse events after bortezomib-based therapy, and treatment-related mortality occurred in 4 of 25 deaths in total.
CONCLUSIONS
Bortezomib-based therapy is a very effective salvage regimen in real clinical practice, although patients relapse after multiple chemotherapies. Despite intolerable in some patients, management of toxicities and extended cycles of therapy could benefit more patients, resulting in higher response rates.