Fig. 4: Correlation of ctDNA with clinical characteristics and therapeutic response.

A–C Levels of ctDNA grouped by disease type. MGUS monoclonal gammopathy of undetermined significance, SMM smoldering myeloma, MM multiple myeloma, ND newly diagnosed, RR relapsed/refractory, EMD extramedullary disease, hGE/mL human genome equivalent per mL of plasma, ND in x-axes, non-detected. Data are presented as mean ± SD. p-values were calculated by a two-sided Wilcoxon rank-sum test. D, E Correlation of ctDNA levels and clinical biomarkers (M-spike and difference between involved and uninvolved free light chains) by linear regression based on secretory disease status. Correlation coefficients and p-values were calculated using a two-tailed Spearman’s rank-order test. F Waterfall plot of quantified molecular response (log10-transformed fold-change in ctDNA from day 0 to day 28 post-treatment). Cases are categorized and color-coded according to the best response as assessed by IMWG criteria. The p-value was calculated by a two-sided Wilcoxon rank-sum test. VGPR very good partial response, PR partial response, SD stable disease, MR minimal response, PD progressive disease.