Folate receptor alpha (FOLR1) and MUC1 are overexpressed in various cancers, suggesting potential as therapeutic targets. A bispecific antibody (BCG023 bsAb) targeting both FOLR1 and MUC1 was developed from monoclonal antibodies using RenLite® technology. BCG023 demonstrated binding to ovarian, breast, and NSCLC cell lines, with enhanced internalization observed in specific cell lines. Conjugated to vcMMAE, BCG023 exhibited superior tumor growth inhibition in a low FOLR1-expressing NSCLC PDX model compared to benchmark ADCs. These findings suggest that dual targeting of FOLR1 and MUC1 with a bispecific ADC holds promise for ovarian and other cancers, warranting further preclinical development.