BC281

BC281 is a murine bispecific T-cell engager (T-BsAb) designed to simultaneously target the Interleukin-33 receptor (Il1rl1, also known as ST2) and the CD3 epsilon subunit of the T-cell receptor complex. Developed using the "da vinci" IgG[L]-scFv 2 + 2 platform, it features two anti-CD3 arms attached to the carboxyl end of each light chain of an Il1rl1-specific IgG. The antibody incorporates a silenced Fc domain to eliminate non-specific FcγR binding and complement activation, thereby improving T-cell trafficking and reducing off-target toxicity. BC281 is primarily investigated for the treatment of acute myeloid leukemia (AML), where it functions by redirecting cytotoxic T cells to eliminate both leukemia stem cells (LSCs) and immunosuppressive cells within the bone marrow niche, such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). By disrupting the stress-induced IL-33/Il1rl1 autocrine loop, BC281 inhibits leukemia initiation and maintenance while reversing tumor-mediated immune tolerance.

Other names

anti-Il1rl1 T-BsAbanti-Il-1rl1 T-BsAbanti-Il 1rl1 T-BsAbanti-ST2 T-BsAbanti-ST-2 T-BsAbanti-ST 2 T-BsAbmIl1rl1 T-BsAbmIl-1rl1 T-BsAbmIl 1rl1 T-BsAb