ABBV-519

ABBV-519 is an investigational, afucosylated monoclonal antibody targeting CD19, developed by AbbVie for the treatment of autoimmune diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). It is the unconjugated version of ABBV-319, a CD19-targeted antibody-drug conjugate (ADC) that carries a glucocorticoid receptor modulator (GRM) payload. ABBV-519 is designed to deplete B cells and inhibit B-cell hyperactivity, which are central to the pathogenesis of SLE and RA. The antibody's afucosylation enhances its affinity for Fcγ receptors (particularly FcγRIIIa), thereby increasing its ability to induce antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Additionally, it acts as an antagonist by inhibiting CD19-mediated signaling pathways. ABBV-519 is currently being evaluated in Phase 1 clinical trials to assess its safety, pharmacokinetics, and pharmacodynamics in adult participants with moderate SLE or RA.