Zenas BioPharma is a clinical-stage biopharmaceutical company developing treatments for autoimmune and inflammatory diseases. Zenas has no approved products or revenue yet, and funds operations through equity raises, licensing payments, and partnerships. Zenas' lead asset is obexelimab, a bifunctional monoclonal antibody that inhibits B cell activity by targeting two receptors (CD19 and FcγRIIb) without destroying B cells outright — a key distinction from competing B cell-depleting therapies like rituximab, which can suppress B cells for six months or longer. Obexelimab's B cell levels recover within about six weeks of stopping treatment, which may offer a more favorable infection and vaccination profile. Zenas is pursuing obexelimab across three indications: IgG4-related disease (IgG4-RD), where a Phase 3 trial showed a 56% reduction in disease flare risk vs. placebo and a BLA filing with the FDA is planned for Q2 2026; relapsing MS, where a Phase 2 trial showed a 95% reduction in new brain lesions vs. placebo; and lupus, where a Phase 2 trial is ongoing with data expected in Q4 2026. Zenas' second key asset is orelabrutinib, an oral BTK inhibitor in-licensed from InnoCare that crosses the blood-brain barrier to target neuroinflammation, and is in Phase 3 trials for progressive MS. Earlier-stage pipeline assets include oral small molecules targeting IL-17 and TYK2. Zenas in-licensed obexelimab from Xencor and has partnered with Bristol-Myers Squibb, which holds commercialization rights in select Asia-Pacific markets and paid Zenas $50M upfront. Zenas plans to commercialize directly in the U.S. and Europe if products are approved.