A comparison of bortezomib, cyclophosphamide, and dexamethasone (Vel-CD) chemotherapy without and with thalidomide (Vel-CTD) for the treatment of relapsed or refractory multiple myeloma

We compared the clinical responses and toxicities between bortezomib-based salvage chemotherapy combined with cyclophosphamide, thalidomide, and dexamethasone (Vel-CTD) and without thalidomide (Vel-CD) in patients with relapsed or refractory MM. Eighty-six patients received at least two cycles of treatment with Vel-CTD (bortezomib 1.3 mg/m² i.v. on days 1, 4, 8, and 11; cyclophosphamide 150 mg/m² orally on days 1–4; thalidomide 50–100 mg/day orally every day; and dexamethasone 20 mg/m² i.v. on days 1, 4, 8, and 11 every 3 weeks), and 67 patients were given at least two cycles of Vel-CD, which is the same regimen as Vel-CTD except without thalidomide. The overall response rates of the Vel-CD and Vel-CTD groups were 88% and 90% (p > 0.05), respectively. There was no difference in the progression free survival (p = 0.69) and overall survival rates (p = 0.49) between the two groups. Grade 3 or more adverse hematologic events occurred in the same proportion of patients in both groups. In terms of non-hematologic toxicities, the Vel-CTD group showed a higher proportion of autonomic neuropathy, motor neuropathy, and sensory neuropathy compared to the Vel-CD group (each, p < 0.05). Only three patients in the Vel-CTD group showed thrombotic events despite aspirin prophylaxis. The Vel-CD regimen in patients with relapsed or refractory MM is an effective and more tolerable salvage therapy compared to Vel-CTD in terms of its comparable response rate and less severe of non-hematologic toxicities.