Zenas Announces Obexelimab Data at Rheumatology Conferences

WALTHAM, Mass., Sept. 22, 2026 /CourierPR/ -- Zenas BioPharma, a clinical-stage global biopharmaceutical company focused on the development and commercialization of therapies for autoimmune diseases and inflammatory conditions, announced new data from the Phase 3 INDIGO trial evaluating obexelimab in immunoglobulin G4-related disease (IgG4-RD) at two upcoming scientific meetings. The presentations will be held at the 6th International Symposium on IgG4-Related Disease, taking place October 8-10, in Cambridge, Massachusetts, and American College of Rheumatology (ACR) Convergence 2026, taking place November 6-11, 2026, in Orlando, Florida.

Longer-term flare protection and safety data from the INDIGO open-label extension will be presented on October 10 at the 6th International Symposium on IgG4-Related Disease. Additional analyses will include assessments of glucocorticoid-associated toxicity and vaccine responses among patients with IgG4-RD treated with obexelimab.

Obexelimab is a bifunctional monoclonal antibody designed to bind both CD19 and FcγRIIb, which are broadly present across B cell lineage, to inhibit the activity of cells that are implicated in many autoimmune diseases without depleting them. The antibody has been evaluated in nine clinical trials in a total of 667 subjects, including INDIGO. Obexelimab has been well tolerated and demonstrated clinical activity across these clinical trials. The Phase 2 SunStone trial in Systemic Lupus Erythematosus (SLE) topline results are expected in the fourth quarter of 2026.

IgG4-related disease (IgG4-RD) is a rare, chronic immune-mediated disease that can cause inflammation and fibrosis in multiple organs throughout the body. Because symptoms can appear suddenly or develop gradually, and may be mistaken for other conditions, many people face a 5- to 7-year journey to diagnosis. IgG4-RD can worsen and cause irreversible damage if it is not diagnosed and managed properly. About 20,000 people in the United States have been diagnosed with IgG4-RD, but the true number of people living with the disease may be closer to 40,000 because some individuals remain undiagnosed.

Zenas is committed to advancing the scientific understanding of IgG4-RD and the potential role of obexelimab in addressing the needs of people living with this rare, chronic, immune-mediated disease. The upcoming presentations at the 6th International Symposium on IgG4-Related Disease and ACR Convergence 2026 build on the Phase 3 INDIGO results presented earlier this year and reflect the company's continued focus on advancing therapies that may help people living with IgG4-RD.

Obexelimab may broadly and effectively modulate the pathogenic role of the B cell lineage in chronic autoimmune disease. The company's earlier stage programs include ZB021, a novel, clinical-stage, potentially best-in-class, oral, IL-17AA/AF inhibitor, ZB022, a preclinical, potentially best-in-class, oral, brain-penetrant, TYK2 inhibitor, and ZB014, a preclinical, half-life extended anti-CD19 and FcγRIIb monoclonal antibody.

Zenas BioPharma, Inc. ("Zenas" or the "Company") (Nasdaq: ZBIO)