Daizo Yokoyama, Daisuke Minakata, Shin-Ichiro Fujiwara, Seina Honda, Ryutaro Tominaga, Atsuto Noguchi, Shuka Furuki, Shunsuke Koyama, Rui Murahashi, Hirotomo Nakashima, Kazuki Hyodo, Shin-Ichiro Kawaguchi, Yumiko Toda, Kento Umino, Masuzu Ueda, Masahiro Ashizawa, Chihiro Yamamoto, Kaoru Hatano, Kazuya Sato, Ken Ohmine, Yoshinobu Kanda
This single-institution retrospective study evaluated a measurable residual disease (MRD)-guided induction intensification strategy in transplant-eligible patients with newly diagnosed multiple myeloma treated in the anti-CD38 antibody era. Sixty patients undergoing autologous stem cell transplantation (ASCT) between 2020 and 2025 were included. Most received bortezomib, lenalidomide, and dexamethasone as initial therapy. Patients with persistent MRD by multiparameter flow cytometry underwent treatment intensification, commonly with daratumumab, carfilzomib, and dexamethasone before ASCT. Among 52 evaluable patients, 35 (67.3%) achieved MRD negativity before ASCT, and 30 of 32 (93.8%) were MRD-negative after ASCT. Stem cell mobilization and engraftment were successful. After median follow-up of 28.5 months, 2-year progression-free and overall survival were 87.3% and 98.0%. R-ISS stage III and extramedullary disease were associated with inferior progression-free survival. High-risk cytogenetics showed poorer outcomes. This MRD-adapted strategy was feasible, achieved deep responses, and preserved mobilization, but high-risk disease remained prone to relapse, supporting post-transplant intensification.