Celldex Therapeutics, Inc.

Celldex Therapeutics, Inc. is a biopharmaceutical company focused on mast cell biology and developing therapeutic antibodies. The company aims to improve the lives of patients with severe inflammatory, allergic, autoimmune, and other devastating diseases by developing drug candidates, including monoclonal and bispecific antibodies, designed to address mast cell mediated diseases where current treatments are insufficient. Celldex is concentrating its resources on the research and development of Barzolvolimab (also known as CDX-0159). This is a monoclonal antibody that specifically binds and potently inhibits the KIT receptor. Barzolvolimab is currently being studied across multiple mast cell driven diseases. For Chronic Spontaneous Urticaria (CSU), enrollment in Phase 3 studies was completed in February 2026, with topline data expected in the fourth quarter of 2026. In November 2023, a Phase 2 study in CSU achieved its primary efficacy endpoint and was well tolerated. Data from 52 weeks of treatment, reported in September 2024, demonstrated sustained and deepening disease efficacy and a well-tolerated long-term safety profile. In June 2025, longer-term follow-up data at 76 weeks showed that 7 months after completing barzolvolimab dosing, over 40% of patients (150 mg Q4W) continued to experience profound, sustained complete response and improved quality of life. For Cold Urticaria (ColdU) and Symptomatic Dermographism (SD), a Phase 3 study was initiated in December 2025, and enrollment is ongoing.