This study evaluated the performance of mass spectrometry (MS), serum protein electrophoresis /immunofixation electrophoresis (IFE), and next-generation flow cytometry (NGF) for detecting minimal residual disease (MRD) in patients with high-risk smoldering multiple myeloma. The treatment protocol included induction with KRd, autologous stem cell transplant (ASCT), consolidation, and maintenance. The primary endpoint was MRD negativity at three months post-ASCT, with results showing MS had the highest sensitivity for detecting residual disease, particularly during intensive treatment phases. Both MS and NGF performed similarly during maintenance, with MS detecting more cases during the early stages of treatment. The study highlighted the potential of MS as a clinical monitoring tool due to its high sensitivity compared to IFE and its ability to complement MRD detection through NGF.

Furthermore, the dynamics of MRD and peripheral residual disease (PRD) were found to be important prognostic indicators. Sustained MRD or PRD negativity was associated with favorable progression-free survival, while sustained positivity or conversions from negative to positive were linked to a higher risk of disease progression. The study also revealed that MS and NGF, both with high negative predictive values, could be used to determine the optimal timing for bone marrow aspiration to confirm MRD negativity in patients.

Reference: Puig N, Agulló C, Contreras T, et al. Single-point and kinetics of peripheral residual disease by mass spectrometry to predict outcome in patients with high-risk smoldering multiple myeloma included in the GEM-CESAR trial. Haematologica. 2024;109(12):4056-4066. doi: 10.3324/haematol.2024.285742.