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. 

Our lead I&I (immunology and inflammation) 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. 

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 planned Phase 2, double-blind, randomized, placebo-controlled trials each of which we plan to commence 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.

We estimate that the commercial opportunity across these four indications is approximately $50 billion in the aggregate in the U.S. alone.

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.

Note: Net loss and collaboration revenue are for the 12 months that ended Dec. 31, 2023. The company has no revenue from product sales.

(Note: Zenas BioPharma upsized its IPO at pricing to 13.24 million shares (13,235,294 shares) – up from 11.76 million shares in the prospectus – and priced its IPO at $17.00 – the mid-point of its $16.00-to-$18.00 range – to raise $225.0 million on Thursday night, Sept. 12, 2024.)

(Note: Zenas BioPharma filed its S-1/A on Sept. 6, 2024, and disclosed the terms for its IPO: The company is offering 11.76 million shares at a price range of $16.00 to $18.00 to raise $199.92 million, if priced at the $17.00 mid-point. Background: Zenas BioPharma Inc. filed its S-1 on Aug. 22, 2022, without disclosing the terms for its IPO. Estimated IPO proceeds are $100 million, a placeholder figure.)