Bortezomib, cyclophosphamide, dexamethasone versus lenalidomide, cyclophosphamide, dexamethasone in multiple myeloma patients at first relapse.

Bortezomib- and lenalidomide-containing regimens are well-established therapies in multiple myeloma (MM). However, despite their extensive use, head-to-head comparisons have never been performed. Therefore, we compared bortezomib and lenalidomide in fixed-duration therapies. In this open-label, phase III study, we randomized MM patients at first relapse to receive either nine cycles of bortezomib plus cyclophosphamide plus dexamethasone (VCD) or lenalidomide plus cyclophosphamide plus dexamethasone (RCD). The primary endpoint was achievement of a very good partial response (VGPR) or better at six weeks after nine treatment cycles. From March 2011 to February 2015, 155 patients were randomized. VGPR or better was achieved by 12 patients (15%) in the VCD arm and 14 patients (18%) in the RCD arm (P = 0·70). Median progression-free survival (PFS) was 16·3 (95% CI: 12·1-22·4) with VCD and 18·6 months (95% CI: 14·7-25·5) with RCD, and the two-year overall survival (OS) was 75% (95% CI: 66-86%) and 74% (95% CI: 64-85%) respectively. In subgroup analyses, no differences in PFS were observed in bortezomib- and lenalidomide-naïve patients, nor in patients who received a bortezomib-based regimen in first line. Adverse events were consistent with the well-established safety profiles of both drugs. Bortezomib and lenalidomide treatments were equally effective in terms of depth of response, PFS, and OS in MM patients at first relapse.