To evaluate the prognostic value of minimal residual disease (MRD) status before and after autologous stem cell transplantation (ASCT) and MRD dynamic changes in patients with newly diagnosed multiple myeloma (NDMM). This retrospective cohort study included 301 consecutive NDMM patients who underwent upfront ASCT between 2016 and 2023 and had paired pre-ASCT and post-ASCT (approximately day + 100) MRD assessments using a single institutional next-generation flow cytometry assay with a target sensitivity of at least 1 × 10 −5 . The primary endpoints were progression-free survival (PFS) and OS. Multivariable Cox analyses were performed in the 142-patient complete-case subset with available cytogenetic risk data. Pre-ASCT and post-ASCT MRD negativity rates were 45.2% and 62.5%, respectively. Post-ASCT MRD negativity was associated with superior PFS (not reached 95% CI 56.8-NR vs 28.4 months 95% CI 23.1–35.7, log-rank P < 0.001) and OS (not reached 95% CI 68.9-NR vs 52.1 months 95% CI 43.6–63.8, log-rank P < 0.001). In the complete-case multivariable Cox analysis, post-ASCT MRD positivity remained independently associated with inferior PFS (HR 2.45, 95% CI 1.45–4.12; P = 0.001) and OS (HR 2.17, 95% CI 1.18–3.99; P = 0.013). Patients who converted from MRD positive to MRD negative after ASCT had outcomes approximating the sustained MRD-negative group. Serial MRD assessment before and after ASCT provides clinically relevant prognostic information for posttransplant risk stratification in NDMM. These findings are prognostic and support prospective evaluation of MRD-informed management rather than immediate treatment modification.
Jin et al. (Wed,) studied this question.