A PROSPECTIVE study presented new evidence supporting the use of dual measurable residual disease (MRD) assessment, using both bone marrow flow cytometry and 18F-FDG PET/CT imaging, in evaluating treatment response in multiple myeloma patients following autologous stem cell transplantation (ASCT). It was recently presented at the 2025 COMy (Controversies in Multiple Myeloma) Congress.
Conducted between November 2022 and December 2024, the study followed 37 consecutive patients with multiple myeloma who underwent high-dose chemotherapy and ASCT. MRD was evaluated on day +100 post-transplant using flow cytometry and 18F-FDG PET/CT imaging.
Post-transplant results showed that 91.9% of patients achieved complete response (CR), and 67.6% were minimal residual disease (MRD) negative by bone marrow flow cytometry. On Day +100 after autologous stem cell transplantation (ASCT), 70.3% of patients were both flow MRD negative and PET negative. In contrast, 10.8% were flow MRD negative but PET positive, and 8.1% were positive for both flow MRD and PET. The likelihood of MRD negativity was linked to a better response to initial treatment and chemo-sensitive disease prior to transplant.
Patients who were MRD negative by flow cytometry showed significantly improved progression-free survival (PFS) compared to MRD-positive patients, with a mean PFS of 27.7 months (p < 0.05). At a median follow-up of 15.5 months, four patients relapsed, three of whom were MRD positive on Day +100. These findings highlight the predictive value of dual MRD testing (bone marrow flow cytometry and PET/CT) in identifying patients with superior long-term outcomes post-transplant.
The findings support the hypothesis that combining bone marrow MRD detection with PET/CT imaging offers a more robust method for identifying deep remission and predicting long-term outcomes. The study reinforces the role of MRD negativity as a critical treatment milestone in multiple myeloma care.
Reference
Shah I et al. Integrated assessment of measurable residual disease (MRD) by bone marrow flow cytometry and (18) F-FDG PET/CT scan in multiple myeloma post transplant: A prospective study. COMy 2025.
