Zenas BioPharma

Zenas BioPharma is advancing obexelimab—a bifunctional monoclonal antibody targeting CD19 and FcγRIIb—through global clinical trials for several autoimmune diseases. The INDIGO trial in IgG4-RD has completed enrollment for its pivotal Phase 3 study, with topline results expected by year-end 2025. The MoonStone trial in relapsing MS and the SunStone trial in SLE are both ongoing at the Phase 2 stage. Early data suggest that obexelimab’s mechanism may broadly suppress pathogenic B cell activity without depleting cells, potentially offering advantages over existing therapies. Additional pipeline programs include early-stage assets such as ZB002 and ZB004 targeting other autoimmune conditions.