HFB100204

**HFB100204** is an afucosylated, Fc-enhanced human monoclonal antibody developed by HiFiBiO Therapeutics that targets **CXCR5**, a chemokine receptor on B cells and T follicular helper (Tfh) cells. It depletes pathogenic CXCR5+ immune cells via **antibody-dependent cell cytotoxicity (ADCC)** while antagonizing CXCR5 to block CXCL13-dependent signaling, disrupting ectopic germinal center formation and autoantibody production central to autoimmune diseases like Sjögren's syndrome (SjD), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). Preclinical data demonstrate superior potency over rituximab and ianalumab in depleting CXCR5+ B cells from human PBMCs and in hCXCR5-knockin mice, with selective enrichment of autoreactive CXCR5+ cells correlating to SjD disease progression identified via HiFiBiO's DIS® single-cell platform. It is also explored for oncology applications targeting cancers.[1][2][3][5][11]