Baseline and on-treatment MC CD30 expression and BM MC burden. CD30⁺ BM MCs (A), assessed by multiparameter flow cytometry on the aspirate specimen, as well as BM MC burden (B), BM MC burden, assessed by immunohistochemistry on the core biopsy specimen, did not show significant reductions when compared with pretreatment baseline by Wilcoxon matched pairs signed rank test (i). Pre- and posttherapy assessments are represented for individual patients (i) and for the entire cohort (ii) with each biomarker. Box plot boundaries represent the 75th and 25th percentiles; whiskers denote maximum and minimum values, (+) denotes the cohort’s mean, and symbols represent individual patient values. EOT, end of treatment; FCM, multiparametric flow cytometry; IHC, immunohistochemistry.