Abstract
The aim of this study is to analyze the efficacy and safety of sequential therapy with bortezomib-based triplet regimens without lenalidomide (PXD, including VTD, PAD, and VCD) followed by continuous lenalidomide and dexamethasone (Rd) or bortezomib and dexamethasone (Vd) treatment. The main objective is to evaluate the advantages of PXD followed by Rd compared to the combinations of bortezomib-lenalidomide-dexamethasone (VRd) in newly diagnosed multiple myeloma (NDMM). Fifty-eight nontransplant NDMM patients who were admitted to our department from 2017 to 2019 were included in this study. Bortezomib-based triplet regimens were initially selected and followed by Rd or Vd as continuous treatment once the patients achieved partial remission (PR) or better response. The efficacy and safety of the patients were observed. The Rd continuous treatment cohort was compared with historical data from the EVOLUTION trial on continuous VRd treatment. In our cohort, the overall survival rate was 100%, and progression-free survival (PFS) was 38.5% after a median of 19 (4-36) cycles of Rd continuous therapy was applied. During the follow-up period, the best outcome assessments achieved were 53.8% complete response (CR) and 84.6% excellent partial response (VGPR). A total of 23.1% had grade 3-4 or higher drug-related adverse reactions, mainly hematological toxicity, and no patients died of adverse reactions. Compared with the Vd group, the Rd group had a better PFS and VGPR rate (2-year PFS: 92.3% vs. 56.3%, P = 0.002; 3-year PFS: 69.2% vs. 8.0%, P < 0.001; VGPR: 84.6% vs. 69.2%, P = 0.02). No significant differences were found in ORR (100% vs. 92.3%) or CR (53.8% vs. 35.7%, P = 0.082). Compared with the EVOLUTION study, patients in the Rd group had a more advanced disease stage (stage III rate of 40% vs. 19%, P = 0.039) and worse physical status (KPS 50-60 rate of 25.0% vs. 2.0%, P = 0.000). However, a higher proportion of ORR (100% vs. 73.0%, P < 0.001), VGPR or better (75.0% vs. 32.0%, P < 0.001), and PFS at 12 months (90.0% vs. 68%, P = 0.011) were achieved. Sequential administration of bortezomib-based triplet regimens without lenalidomide as an initial therapy followed by Rd as a continuous treatment may not be inferior to VRd for first-line treatment in NDMM patients.