The antibody-drug conjugate BT062 (Biotest AG, Dreieich, Germany), comprising an anti-CD138 chimerized antibody conjugated to the cytotoxic compound, maytansinoid, has been evaluated both as monotherapy, and in combination with either lenalidomide or pomalidomide and low-dose dexamethasone, and was shown to have an acceptable safety profile with preliminary evidence of activity in patients with relapsed/refractory MM [17–19]. Here, SDC1 is linked to Miyoshi myopathy.