HMBD-009

**HMBD-009** is a next-generation, dual-specific T cell engager developed by Hummingbird Bioscience using its Rational Antibody Discovery platform. It targets both **B-cell maturation antigen (BCMA)** and **transmembrane activator and CAML interactor (TACI)**, proteins commonly co-expressed and overexpressed on malignant plasma cells in **multiple myeloma (MM)**, the second most common hematologic malignancy. By binding a conserved epitope on BCMA and TACI with sub-nanomolar affinity, HMBD-009 redirects T cells via CD3 engagement to induce potent cytotoxicity against MM cells expressing either or both targets, addressing resistance to BCMA-only therapies due to antigen loss; preclinical data show superior tumor control over BCMA monotherapy in MM models, with efficient ADCC and no cross-reactivity to other TNFR family members.[1][3][5]