6B5 and 10F7, two anti-human B7-H3 clones, are preclinical candidates suitable for different modalities of B7-H3-targeted therapies. 6B5 is a high affinity, highly B7-H3-selective, fully human antibody with a distinct binding epitope. 6B5 binds selectively to B7-H3 positive tumor cells with clean normal tissue staining by IHC, unlike reference antibodies. 6B5-AF shows robust ADCC without the hook effect. It demonstrates modest anti-tumor activity in a syngeneic mouse model. 10F7 demonstrates superior internalization activity compared with reference antibodies, which is suitable for ADC discovery. Both 6B5 and 10F7 have excellent developability. CMC development is underway with cell lines generated.