Celldex Completes Enrollment in Global Phase 3 Studies (EMBARQ-CSU1 and EMBARQ-CSU2) of Barzolvolimab in Chronic Spontaneous Urticaria

Core Insights - Celldex has completed enrollment in its global Phase 3 program for barzolvolimab in chronic spontaneous urticaria (CSU), consisting of two trials with a total of 1,939 patients, marking it as the largest program for antihistamine refractory CSU [1][2][3] - The completion of enrollment six months ahead of schedule underscores the significant unmet need for effective treatments in CSU, with topline results expected later in 2026 and a BLA submission planned for 2027 [2][6] Study Design and Objectives - The Phase 3 program aims to establish the efficacy and safety of barzolvolimab in adult patients with CSU who remain symptomatic despite H1 antihistamine treatment, involving randomized, double-blind, placebo-controlled trials [3] - Patients were randomized to receive either barzolvolimab 150 mg every 4 weeks, 300 mg every 8 weeks, or placebo for 52 weeks, with the primary endpoint focusing on reducing urticaria activity at Week 12 [3] Clinical Efficacy - Barzolvolimab targets mast cells, potentially transforming the treatment landscape for CSU by providing rapid and durable efficacy, with up to 51% of patients achieving complete response at 12 weeks, increasing to 71% at 52 weeks [2][5] - Significant improvements were reported in angioedema control and quality of life, with up to 65% of patients being angioedema-free at 12 weeks, rising to 77% at Week 52 [2][5] Patient Impact - CSU is characterized by spontaneous hives and angioedema, leading to a substantial mental health burden and a 1.7-fold increase in all-cause mortality over five years, highlighting the critical need for effective treatments [8] - The goal of CSU treatment is complete symptom absence, yet many patients continue to experience significant distress despite current therapies [8] Future Directions - Barzolvolimab is being studied not only in CSU but also in other conditions such as cold urticaria and symptomatic dermographism, with additional indications planned for the future [7] - A global Phase 3b long-term extension study is ongoing, allowing patients to continue treatment after the Phase 3 trials [3]