Zenas BioPharma Submits BLA for Obexelimab to FDA

Zenas BioPharma announced the submission of its biologics license application, or BLA, to the FDA for obexelimab in Immunoglobulin G4-Related Disease. IgG4-RD is a debilitating chronic fibro-inflammatory disease affecting multiple organ systems, often resulting in irreversible tissue damage and organ failure. Obexelimab, an investigational therapy, is a bifunctional monoclonal antibody designed to bind both CD19 and FcgRIIb to inhibit B cell function. The BLA submission is supported by the results of the Phase 3 INDIGO registrational trial of obexelimab for the treatment of IgG4-RD. In INDIGO, obexelimab met the primary endpoint, demonstrating a highly statistically significant and clinically meaningful 56% reduction in the risk of IgG4-RD flare compared to placebo during the 52-week randomized placebo-controlled period. Obexelimab also met and demonstrated highly statistically significant activity compared to placebo on all four key secondary endpoints and was generally well tolerated. Data from the INDIGO trial will be presented during an oral session at the European Alliance of Associations for Rheumatology 2026 Congress in London, UK, on June 4.