05:03 PM EDT, 08/19/2025 (MT Newswires) -- Celldex Therapeutics ( CLDX ) said Tuesday it will not advance development of barzolvolimab in eosinophilic esophagitis after topline results from a phase 2 study showed the drug met its primary endpoint, but the mast cell depletion observed did not result in clinical improvement.

The trial met the primary endpoint of absolute change in peak esophageal intraepithelial mast cell count at week 12, with barzolvolimab producing profound mast cell depletion compared to placebo.

However, the company said the reduction did not result in an improvement in eosinophilic esophagitis symptoms or endoscopic assessment of disease activity versus placebo.

Celldex said barzolvolimab maintained a favorable safety profile, consistent with previous studies. The company said it will not pursue the therapy in eosinophilic esophagitis but continues to advance development in other indications, including spontaneous urticaria, atopic dermatitis, and prurigo nodularis.

The company's shares were down more than 15% in after-hours activity.