FIGURE 2 from Discovery and Preclinical Activity of BMS-986351, an Antibody to SIRPα That Enhances Macrophage-mediated Tumor Phagocytosis When Combined with Opsonizing Antibodies

Binding affinity of BMS-986351 to SIRPα (A), SIRPβ (B), and SIRPγ (C) as determined by SPR and inhibition of CD47-SIRPα binding (D). E, Cocrystallization of BMS-986351 with SIRPα (structure available in the Protein Data Bank, entry 7ST5) indicates that the site of interaction between the Fab epitope (the CDR H3 loop) of BMS-986351 (blue) and the SIRPα IgV domain overlaps considerably with the CD47-SIRPα binding domain. The positions of the DLN motif haplotype residues, away from the site of interaction, are highlighted in magenta.