Despite advances in treatments, multiple myeloma (MM) remains an incurable cancer where relapse is common. We developed a circulating tumor DNA (ctDNA) approach in order to characterize tumor genomics, monitor treatment response, and detect early relapse in MM. By sequencing 412 specimens from 64 patients with newly diagnosed or relapsed/refractory disease, we demonstrate the correlation between ctDNA and key clinical biomarkers, as well as patient outcomes. We further extend our approach …