To the Editor: In the study by Mateos et al. (Aug. 1 issue)1 involving patients with high-risk smoldering multiple myeloma, early treatment with lenalidomide plus dexamethasone, as compared with observation, resulted in a delay in progression to symptomatic disease and an increase in overall survival. Currently, the standard of care for patients with smoldering multiple myeloma has been observation until symptomatic disease occurs.2 Patients in the trial by Mateos et al. met at least one of two sets of inclusion criteria based on a definition of “high-risk” disease. The first set included plasma-cell bone marrow infiltration of 10% or more . . .