Celldex Halts Barzolvolimab Development in Eosinophilic Esophagitis After Phase II Setback

Celldex Therapeutics will discontinue development of its monoclonal antibody barzolvolimab in eosinophilic esophagitis (EoE) following disappointing Phase II data, though the drug will continue in other indications.

In the EvolvE trial (NCT05774184), barzolvolimab achieved its primary endpoint, reducing peak mast cell counts by 72%. However, it failed to improve Endoscopic Reference Scores (EREFS), a key marker of disease severity (p=0.95), or alleviate symptoms such as swallowing difficulties, as measured by the Dysphagia Symptom Questionnaire (DSQ). Reductions in eosinophil counts were also not statistically significant.

The decision cements Sanofi and Regeneron’s Dupixent (dupilumab) as the leading therapy in EoE. Since its first U.S. approval in 2022, Dupixent has expanded into pediatric use and generated $14.1bn in 2024, with sales projected to hit $25.3bn by 2031. Future competitors include AstraZeneca and Amgen’s Tezspire, now in Phase III trials, and Takeda’s Eohilia, FDA-approved in 2024.

23-08-2025