BC283

BC283 is a humanized control T-cell engaging bispecific antibody (T-BsAb) utilized in preclinical research for acute myeloid leukemia (AML). It serves as the non-functional control for BC282, an active bispecific antibody designed to target IL1RL1 (ST2) on leukemia stem cells and CD3 on T cells. BC283 is built on the IgG[L]-scFv 2+2 'da vinci' platform, which features a silenced Fc domain through N297A and K322A mutations to eliminate non-specific FcγR binding and C1q complement activation. In experimental models, including humanized xenografts and patient-derived xenograft (PDX) models, BC283 is used to validate the specific therapeutic efficacy of IL1RL1-targeted T-cell engagement by providing a structurally identical but non-targeting comparator.