Bortezomib and Thalidomide Treatment Results in Newly Diagnosed Transplant-Ineligible Multiple Myeloma Patients are Comparable in Long-Term Follow-Up.

Abstract

Thalidomide-and bortezomib-containing regimens are widely used for transplant-ineligible newly diagnosed multiple myeloma patients. The aim of this study was to analyse the efficiency of thalidomide-or bortezomib-based regimens in long-term follow-up. From 2008 to 2012, 142 transplant-ineligible newly diagnosed multiple myeloma patients were analysed retrospectively. Bortezomib was administered at the standard dosing of 1.3mg/m2 weekly, and thalidomide was administered at a daily dose of 100mg. Both drugs were combined with cyclophosphamide and dexamethasone. A total of 95 patients were treated with thalidomide and 47 with bortezomib. A median four cycles of treatment were administered in both groups. In the thalidomide group, the overall response rate was 60.6%, the median progression-free survival (PFS) was 10.3 months (95% CI 7.4-13.2) and the median overall survival (OS) was 35.1 months (95% CI 23.9-46.3). In the bortezomib group, the overall response rate was 51.1%, the median PFS was 11.9 months (95% CI 8.8-15) and the median OS was 25.4 months (95% CI 9.3-41.6). There was a statistically significant difference in OS (p = 0.027), favouring the cyclophosphamide/thalidomide/dexamethasone group, but the response rates and PFS intervals were not significantly different between both groups. The median follow-up in the thalidomide group was 35.1 months (95% CI 0.2-95.9) compared to 25.1 months (95% CI 0.4-60.6) in the bortezomib group (p = 0.004). The incidence of serious adverse events was comparable in both groups. In conclusion, the results of bortezomib treatment are comparable to thalidomide treatment under conditions of short administration. According to other clinical trials, long-term bortezomib treatment provides an additional advantage for PFS and OS.