Once-Weekly 1.6 mg/m² Bortezomib BCD Regimen in Elderly Patients with Newly Diagnosed Multiple Myeloma Who are Unfit for Standard Dose Chemotherapy

Bortezomib has shown anti-myeloma effects in combination with alkylating agents, but clinical benefits can be limited by neurotoxicity. There is less information on the efficacy and tolerability of once-weekly 1.6 mg/m² bortezomib combined with cyclophosphamide and dexamethasone (BCD) regimen in elderly patients with newly diagnosed multiple myeloma who are unfit for standard dose chemotherapy. Here, we report our experience of weekly 1.6 mg/m² intravenous bortezomib in this group of patients. Between March 2010 and February 2015, we treated 34 newly diagnosed elderly patients with the combination of bortezomib 1.6 mg/m² intravenously on days 1 and 8; cyclophosphamide 200 mg/m² intravenously on days 1–4; dexamethasone 20 mg intravenously on days 1–4, and 8–11. Among the 34 patients, 14 (41 %) responded with complete response (CR), 6 (18 %) with very good partial response (VGPR) and 10 (29 %) with partial response (PR). The overall response rates were 88 %. After 2 cycles of treatments, the survival of patients who attained a response of VGPR or CR was significantly longer than those with PR or resistance to BCD, for both progression-free survival (PFS) (21.4 vs. 10.6 months, p = 0.002) and overall survival (OS) (23.0 vs. 16.8 months, p = 0.043). The 2-year PFS and OS were 26.5 and 64.7 % respectively in these elderly multiple myeloma patients in our study. Grade 1/2 neuropathy was observed in 20 % of the cycles while grade 3/4 neuropathy was not observed. No patients withdrew due to neuropathy or other side effects. Once-weekly bortezomib at 1.6 mg/m² BCD regimen is both effective and safe in elderly patients with newly diagnosed multiple myeloma who are unfit for standard dose chemotherapy.