Definition

A differentiated human monoclonal antibody targeting the complement component fragment 5a receptor (C5aR1, CD88), with potential immunomodulating and antineoplastic activities. Upon administration, the anti-C5aR1 monoclonal antibody TJ210 specifically targets and binds to the N-terminus of C5aR1 expressed on subsets of tumor-promoting cells, such as myeloid-derived suppressor cells (MDSCs), neutrophils and M2 macrophages. This prevents the binding of its ligand complement factor 5a (C5a) to C5aR1 and prevents the C5aR1-mediated activation, migration and accumulation of the C5aR1-expressing cells in the tumor microenvironment (TME). This abrogates the secretion of inflammatory and angiogenic factors by these cells and restores the activation of T and natural killer (NK) cells. This results in the induction of anti-tumor immune responses and inhibits tumor cell proliferation. C5a, a factor in the complement cascade, is often overexpressed in the TME, where it attracts and activates C5aR1-expressing tumor-promoting immune cells, and contributes to tumor immune suppression.