Celldex reports dual Phase 3 successes for barzolvolimab in refractory chronic spontaneous urticaria

Celldex Therapeutics announced that its monoclonal antibody barzolvolimab achieved positive results in two Phase 3 studies of patients with treatment-refractory chronic spontaneous urticaria. The Embarq CSU1 and CSU2 trials met both primary and secondary endpoints, indicating the drug reduced hives and swelling in this difficult-to-treat condition.

Barzolvolimab works by binding to the KIT receptor tyrosine kinase on mast cells, blocking the signals that trigger mast-cell activation and the ensuing inflammatory response. By inhibiting KIT, the antibody aims to curb the release of mediators that cause the itchy welts characteristic of chronic spontaneous urticaria.

The combined studies enrolled 1,939 participants and will continue for a total of 52 weeks to assess longer-term safety and efficacy. Celldex plans to submit a New Drug Application to the FDA in 2027, positioning the product for potential commercial launch to address the high unmet need in this patient population.