Co-expression of EGFR and MUC1 in multiple solid tumors suggests that simultaneous targeting of EGFR and MUC1 with bsADC has the potential to enhance efficacy and improve safety. BSA01 is an EGFR- and MUC1-targeting bsADC derived from the proprietary, RenLite® common light chain, fully human antibody technology. BSA01 binding to MUC1-C* remains membrane-bound after cleavage and exhibits excellent affinity and internalization activity. The EGFR arm of BSA01 was selected to have reduced binding and internalization capability, designed to reduce the known skin toxicity of EGFR targeting. BSA01 demonstrated potent anti-tumor activity in multiple CDX and PDX models, with improved efficacy over parental mAb ADCs and benchmark ADCs in certain models.