[Recent topics in smoldering multiple myeloma: early intervention or active monitoring?]

The current standard of care for smoldering multiple myeloma (SMM) is active surveillance. In Japan, daratumumab has been approved for the treatment of high-risk SMM. Identification of patients most likely to benefit from treatment is essential to prevent end organ damage through early intervention in patients with high-risk SMM while avoiding unnecessary toxicity by selecting active surveillance for lower-risk patients. Risk stratification models based on clinical biomarkers have been developed. Recently, understanding of disease biology has improved with the advent of comprehensive genetic analysis of tumors and the tumor immune microenvironment. Newer risk models integrating genetic biomarkers into clinical parameters are currently being developed. Clinical trials have also evaluated treatment efficacy and safety in patients with high-risk SMM based on each risk model. Recommendations for early intervention must be underpinned by robust evidence demonstrating not only delayed progression but also improved quality of life and/or overall survival.