Celldex has announced the presentation of long-term results from the phase 2 study of barzolvolimab in a flash talk session at the European Academy of Allergy and Clinical Immunology (EAACI) Annual Meeting in Istanbul, Türkiye. The data presented demonstrated that barzolvolimab treatment results in rapid, significant, and durable improvements in angioedema in patients with Chronic Spontaneous Urticaria (CSU) refractory to antihistamines. These results were sustained off-treatment, 7 months after completion of barzolvolimab dosing (week 76). The data continue to demonstrate barzolvolimab’s potential to shift the goal of CSU treatment from symptom control to disease modification and further support the ongoing phase 3 trials of barzolvolimab in CSU.

Diane C Young, MD, Senior Vice President (SVP) and Chief Medical Officer (CMO), Celldex Therapeutics, said, “Angioedema plays a major role in the physical and mental health of the majority of people living with CSU, causing extremely painful swelling and disfigurement that dramatically impacts quality of life. Barzolvolimab has consistently shown profound, lasting results including high rates of complete response, defined as complete absence of itch and hives, and dramatic improvements in quality of life and angioedema control through 52 weeks of therapy and now 7 months after the last dose, demonstrating its potential for disease modification and the ability to change how CSU patients live their lives.”

Angioedema occurs in 55 percent of people with CSU and patients report a mean of 7.7 angioedema episodes annually. Patients with CSU-related angioedema report significantly worse physical and mental health outcomes, lower health-related quality of life, a higher percentage of anxiety and depression, along with significantly increased emergency room visits and hospitalisations compared to patients without angioedema in the US. Similarly, these patients report significantly higher work and activity impairment than those without angioedema. Both patients and physicians report being free of angioedema as an important treatment goal in CSU.

As previously reported, data from the phase 2b trial showed that treatment with barzolvolimab resulted in rapid, significant, and durable improvements in angioedema. Relief from angioedema symptoms began as early as week 1 and deepened over 52 weeks of treatment. Furthermore, newly presented data show that barzolvolimab treatment led to robust and sustained reductions in angioedema symptoms at week 76, demonstrating prolonged off-treatment benefits. Up to 64 percent of patients who had angioedema at baseline were angioedema-free 7 months after the last dose.

Two phase 3 trials of barzolvolimab in CSU are ongoing and enrollment is complete. 1,939 patients were enrolled, the largest program conducted in antihistamine-refractory CSU, including patients with advanced therapy experienced/refractory CSU. The studies included 43 countries across 500 sites. Topline data are anticipated in Q4 2026, supporting a planned BLA submission in 2027.