We are a clinical-stage global biopharmaceutical company committed to being a leader in the development and commercialization of transformative immunology-based therapies for patients in need. With the evolving understanding of the pathogenesis of autoimmune diseases, along with the expansion of promising immunology-based pharmacologic targets, we are building an immunology and inflammation (“I&I”) focused biopharmaceutical company. Our core business strategy combines disciplined product candidate acquisition with strategic deployment of internal expertise and effective use of external resources. We leverage our experienced executive management team and our established networks throughout the biopharmaceutical industry to identify, acquire and develop product candidates that we believe can provide superior clinical benefits to patients living with autoimmune diseases. Our lead I&I product candidate, obexelimab, is a bifunctional monoclonal antibody designed to bind both CD19 and Fcγ receptor IIb (“FcγRIIb”), which are broadly present across B cell lineage, in order to inhibit the activity of cells that are implicated in many autoimmune diseases without depleting them. Based on existing clinical data generated to date, we believe that targeting B cell lineage via CD19 and FcγRIIb can inhibit B cells and has been shown to be well-tolerated. While anti-CD20 or other anti-CD19 targeting agents effectively deplete B cells in systemic circulation, these agents do not fully impact B cells in relevant tissue, and the intermittent dosing regimens of these agents may not provide optimal benefits for all patients. In addition, anti-CD20 and other anti-CD19 targeting agents may cause prolonged depletion of circulating B cells for six months or longer, placing patients at higher risk of opportunistic infections and potentially reducing their ability to respond to, and receive full benefit from, vaccines. We believe obexelimab’s mechanism of action and chronic dosing regimen may broadly and effectively address the pathogenic role of B cell lineage in chronic autoimmune disease. Across five clinical trials, in which 198 subjects were dosed, obexelimab was well-tolerated and demonstrated clinical activity that we believe provides proof-of-concept (“POC”) for obexelimab as a B cell inhibitor for the treatment of patients living with certain autoimmune diseases and, together with its mechanism of action, positions obexelimab to be a potentially differentiated B cell therapy for the treatment of such patients. We are developing obexelimab as a potential I&I franchise for patients in several autoimmune diseases, representing substantial commercial opportunities individually and in the aggregate. The first four indications we are pursuing include immunoglobulin G4-related disease (“IgG4-RD”) through an ongoing registration-directed Phase 3 trial; multiple sclerosis (“MS”) and systemic lupus erythematosus (“SLE”) through Phase 2, double-blind, randomized, placebo-controlled trials each of which we initiated in the third quarter of 2024; and warm autoimmune hemolytic anemia (“wAIHA”) through an ongoing Phase 2/3 trial, currently in the Phase 2 open label portion. IgG4-RD is a chronic fibro-inflammatory condition that can affect virtually all organ systems, including the pancreas, biliary tract, salivary and lacrimal glands, lungs and kidneys. IgG4-RD is a relatively recently described disease that incorporates groups of manifestations that were diagnosed as separate disease entities prior to 2003. We estimate that the currently diagnosed population of IgG4-RD patients in the United States is approximately 20,000, with comparable prevalence rates globally. MS is the most common immune- mediated, chronic inflammatory demyelinating disease of the central nervous system (“CNS”), affecting over two million people worldwide including as many as 1,000,000 in the United States. We estimate a diagnosed prevalence of approximately 650,000 patients in the United States with MS. SLE, the most common form of lupus, is a complex, chronic autoimmune disease characterized most notably by unpredictable flares in joints, skin, kidneys and other vital organs that cause progressive organ damage. According to the Lupus Foundation of America, at least 1.5 million Americans are afflicted by lupus and more than 16,000 new cases are reported annually. It is estimated that five million people throughout the world suffer from some form of lupus, of which 70% suffer from the most common form, SLE. We estimate a diagnosed prevalence of approximately 245,000 patients in the United States having lupus, with approximately 172,000 having SLE. Autoimmune hemolytic anemia (“AIHA”) is an acquired disorder in which autoantibodies directed against a patient’s own red blood cell (“RBC”) membrane antigens lead to their accelerated destruction, and the rate of production of new cells in the bone marrow can no longer compensate for their loss. We estimate that the currently diagnosed population of wAIHA patients in the United States is approximately 40,000, with similar prevalence rates in other countries. We estimate that the commercial opportunity across these four indications is approximately $50 billion in the aggregate in the U.S. alone. To date, we have no product candidates approved for commercial sale in any country and have not generated any revenue from product sales. Zenas BioPharma, Inc. was originally incorporated on November 12, 2019, as Zenas BioPharma (Cayman) Limited as an exempted company organized under the laws of the Cayman Islands. On August 2, 2023, the Company was domesticated as a Delaware corporation and, concurrent therewith, we changed our name from Zenas BioPharma (Cayman) Limited to Zenas BioPharma, Inc. Our principal executive offices are located at 1000 Winter Street, Suite 1200, Waltham, MA 02451.
