Impact of Dara-VTD induction therapy on stem cell mobilization outcomes in newly diagnosed multiple myeloma patients undergoing autologous stem cell transplantation: a multicenter study.

Daratumumab combined with bortezomib, thalidomide, and dexamethasone (Dara-VTD) is a highly effective induction therapy for newly diagnosed multiple myeloma (NDMM) patients eligible for autologous stem cell transplantation (ASCT). However, its impact on stem cell mobilization requires a critical evaluation. This study examines the effects of Dara-VTD on stem cell mobilization and collection outcomes. A multicenter retrospective study included 81 consecutive NDMM patients treated with Dara-VTD (from November 2021 to June 2023). Data on stem cell mobilization and collection were compared with 93 historical VTD patients. Mobilization regimens included cyclophosphamide (CTX), vinorelbine + CTX, and chemotherapy-free approaches, with plerixafor used as rescue therapy. Mobilization success was evaluated by CD34 + cell yield, additional agent use, and leukapheresis sessions required. The median CD34 + yield in the Dara-VTD group was 5.1 million cells/kg, with 96.3% of patients achieving > 2 × 10^6 cells/kg of body weight. Plerixafor use was significantly higher in the Dara-VTD group (56.2%) compared to VTD (4.3%), and CTX-based regimens showed superior mobilization efficacy (p = 0.01). Engraftment was faster in the Dara-VTD group, with median neutrophil and platelet recovery at 11 and 13 days, compared to 12 and 17 days in the VTD group (p < 0.05). Dara-VTD maintains the feasibility of ASCT, with comparable stem cell mobilization and collection outcomes to VTD. Mobilization success is influenced by individualized strategies, with CTX and plerixafor playing key roles in optimizing stem cell yield. Despite the challenges posed by daratumumab, stem cell mobilization remains effective, and Dara-VTD does not compromise the transplant process.