Celldex is a clinical-stage biopharmaceutical company developing antibody therapies for mast cell-driven inflammatory, allergic, and autoimmune diseases. Celldex has no approved products or commercial revenue. Its lead asset is barzolvolimab, a monoclonal antibody that blocks KIT, a receptor on mast cells, thereby suppressing mast cell activity and depleting mast cell numbers. Celldex's thesis is that mast cells are a root driver of many inflammatory and allergic diseases, and that depleting them can produce durable disease control—including in patients who have failed existing therapies like omalizumab. Barzolvolimab is in late-stage development across multiple indications, including chronic spontaneous urticaria (CSU), cold urticaria, symptomatic dermographism, prurigo nodularis, and atopic dermatitis. CSU is the most advanced and largest opportunity, with two global Phase 3 trials enrolling nearly 2,000 patients and topline data expected Q4 2026. Celldex also has an early-stage bispecific antibody, CDX-622, which targets both TSLP and SCF to suppress Type 2 inflammation and mast cell activity, currently in Phase 1. Celldex is pre-revenue and funds operations through capital markets. R&D spend has grown rapidly as barzolvolimab has moved into Phase 3. Celldex plans to either self-commercialize—targeting dermatologists and allergists—or partner for certain geographies and indications. Manufacturing is outsourced to CDMOs, and barzolvolimab is administered via subcutaneous pre-filled syringe, enabling potential self-administration.