SDC1 and Miyoshi myopathy: In a first-in-human phase 1 trial of an anti-CD138 DM4 (a derivative of the cytotoxic agent maytansine)-antibody conjugate in R/R MM patients, patients suffered from common epithelial-related AEs (e.g., hand-foot syndrome, xerophthalmia, stomatitis, and blurred vision) (148).