Measurable residual disease (MRD) status is a critical prognostic indicator in both newly diagnosed and relapsed multiple myeloma (MM), with persistent MRD linked to poorer survival outcomes. However, there is limited data on the clinical value of MRD monitoring during maintenance or observation, though MRD status is believed to be crucial for tailoring treatment duration. Serial MRD assessments, as opposed to evaluations at single points in time, may offer better risk stratification and guide decisions on treatment intensification or cessation.

In a pooled analysis of two phase 3 trials (TOURMALINE-MM3 and MM4), researchers evaluated the impact of MRD dynamics in patients receiving ixazomib maintenance therapy versus placebo. The findings demonstrated that ixazomib significantly improved progression-free survival (PFS) in patients with detectable MRD at randomization. Those converting from MRD-positive to MRD-negative status had similar PFS to patients with sustained MRD negativity. Additionally, MRD status and its changes over time were found to be more prognostic than single-point MRD measurements, underscoring the importance of regular MRD monitoring to optimize treatment strategies.

Reference: Bruno Paiva, Irene Manrique, Meletios A. Dimopoulos, et al. MRD dynamics during maintenance for improved prognostication of 1280 patients with myeloma in the TOURMALINE-MM3 and -MM4 trials. Blood. 2023; 141 (6): 579–591. doi: https://doi.org/10.1182/blood.2022016782