MRD in multiple myeloma: the clinical perspective

Minimal residual disease (MRD) has emerged as a key prognostic factor in multiple myeloma (MM), allowing a more accurate evaluation of treatment efficacy beyond conventional complete remission. High-sensitivity techniques, including next-generation flow cytometry (NGF), next-generation sequencing (NGS), and allele-specific oligonucleotide quantitative PCR, enable detection of residual disease at levels of 10^-5-10^-6. Achieving MRD negativity is consistently associated with prolonged progression-free survival (PFS) and overall survival (OS) across different disease settings. In 2024, the U.S. Food and Drug Administration Oncologic Drugs Advisory Committee unanimously recognized MRD negativity as a primary endpoint in MM clinical trials, reinforcing its role as a validated surrogate of clinical benefit. This review summarizes current MRD detection methods and discusses how MRD assessment, interpreted in the context of recent pivotal clinical trials, may provide a practical framework to guide future treatment strategies in MM.