Anti-CD79b Bispecific Antibody LTZ-301

**Semantic type:** Amino Acid, Peptide, or Protein|Immunologic Factor|Pharmacologic Substance

**Definition:** An Fc-engineered bispecific antibody targeting both the tumor-associated antigen (TAA) B-cell antigen receptor complex-associated protein beta chain (CD79b; B-cell-specific glycoprotein B29) and an as of yet undisclosed innate receptor expressed on myeloid cells, with potential immunomodulating and antineoplastic activities. Upon administration, anti-CD79b bispecific antibody LTZ-301 simultaneously targets and binds to both the undisclosed innate receptor expressed on myeloid cells and to CD79b on CD79b-expressing tumor B-cells, thereby selectively cross-linking CD79b-expressing tumor B-cells with myeloid cells. This may induce antibody-dependent cellular phagocytosis (ADCP) of the tumor B-cells, and may also reprogram myeloid cells to the M1-like macrophage phenotype and activate dendritic cells (DCs), thereby increasing cytokine release and inducing a T-cell-mediated immune response against the tumor B-cells. In addition, Fc-engineering of LTZ-301 allows for enhanced Fc-gamma receptor binding on effector cells, such as natural killer (NK) cells, thereby activating NK cells and antibody-dependent cellular cytotoxicity (ADCC) and further killing tumor cells. CD79b, a critical receptor for successful B-cell development and part of the B-cell receptor (BCR) signaling complex, is widely expressed in certain subtypes of B-cell lymphomas.

**Synonyms:** - CD79b-targeting Myeloid Cell Engager LTZ-301 - LTZ 301 - LTZ-301 - LTZ301