We are advancing a balanced global portfolio of First- and Best-in-Class autoimmune therapeutics in areas of high unmet medical need while meeting the value requirements of the dynamic global healthcare environment.

CompoundPreclinicalPhase 1Phase 2Phase 3
Global Programs
Obexelimab (ZB012; XmAb5871) CD19xFcγRIIB Bifunctional mAb
ZB002 anti-TNFα mAb1
ZB004 CTLA4-lg fusion1
Regional Programs
ZB001 / 011 anti-IGF-1R mAb3
Thyroid Eye Disease
ZB005 anti-active C1s mAb4

1. Differentiated with extended half-life/increased potency

2. Indication selection ongoing

3. Partner: Viridian Therapeutics; 001 Phase 3 ongoing; 011 Phase 1 ongoing; Greater China Rights

4. Partner: Dianthus Therapeutics; Greater China Rights


Obexelimab (ZB012), is a phase III, novel bifunctional antibody with first-in-class potential that inhibits B-cell lineages that express CD19. Simultaneous binding to CD19 and FcγRIIB by obexelimab mimics a natural antigen-antibody complex and down-regulates B-cell activity. In early-stage clinical studies, obexelimab effectively demonstrated inhibition of B-cell function without depleting the cells and generated an encouraging treatment effect in patients with multiple autoimmune diseases. Zenas acquired exclusive worldwide rights to obexelimab from Xencor, Inc.

IgG4-related disease (IgG4-RD)

IgG4-RD is a chronic and serious, fibroinflammatory disease typically affecting multiple organs and sites (e.g., pancreas, liver, kidney, bile duct, salivary and lacrimal glands). ~20K people are diagnosed with IgG4-RD in the US, with similar prevalence rates across geographies. Many patients have some degree of irreversible organ damage at the time of diagnosis. Although nearly all patients initially respond to first line glucocorticoid (GC) therapy, Chronic GC therapy is associated with toxicity and relapse is common as patients are tapered off or tapered to low doses.

More information regarding Zenas’ phase 3 trial evaluating Obexelimab for the prevention of flare in patients with IgG4-RD can be found here.

Warm autoimmune hemolytic anemia (wAIHA)

wAIHA is a type of autoimmune hemolytic anemia driven by IgG autoantibody binding to red blood cells causing the premature destruction of healthy red blood cells (hemolysis). wAIHA is the most common subtype of autoimmune hemolytic anemias (70 – 80% of cases). Over 40K people in the US and another 40K in the EU are impacted by the disease. While response to initial treatment is relatively high, ~75% become refractory. 

More information regarding Zenas’ phase 3 trial to evaluate the efficacy and safety of Obexelimab in patients with wAIHA can be found here.

ZB002 and ZB004

In addition to Obexelimab, Zenas owns exclusive worldwide rights to ZB002 and ZB004. ZB002 is a potential Best-in-Class anti-TNFα therapy with an extended half-life and less ADCC off-target activity as compared to existing anti-TNFα therapies. ZB004 is a potential Best-in-Class CTLA4-Ig fusion protein with an extended half-life and increased potency versus existing CTLA4-Ig fusion protein therapies. Zenas acquired exclusive worldwide rights to ZB002 and ZB004 from Xencor, Inc.


ZB001, is an insulin-like growth factor-1 receptor (IGF1R) monoclonal antibody (mAb) that we are developing for the potential treatment of patients with thyroid eye disease (TED). TED is a debilitating condition that significantly impacts quality of life and can cause proptosis (“bulging eyes”), double vision and vision loss. Zenas exclusively licensed China rights to develop and commercialize ZB001 from Viridian Therapeutics, Inc. ZB001 has First-in-Class potential in China and the program is advancing rapidly.