Celldex Begins Phase 3 Trials for Barzolvolimab in Chronic Spontaneous Urticaria

Celldex Therapeutics, Inc. has announced the launch of its global Phase 3 program, consisting of two trials, EMBARQ-CSU1 and EMBARQ-CSU2. These trials aim to validate the efficacy and safety of barzolvolimab in adult patients with Chronic Spontaneous Urticaria (CSU), who continue to experience symptoms despite H1 antihistamine treatments. The studies also include patients who remain symptomatic after treatment with biologics.

CSU is characterized by episodes of itchy hives, swelling, and skin inflammation caused by the activation of mast cells. This condition can severely affect the quality of life of patients for extended periods. Current treatment options are limited, especially for those not adequately managed by omalizumab. Barzolvolimab, a novel monoclonal antibody, targets the root cause of the disease by blocking the receptor tyrosine kinase KIT, crucial for mast cell function and survival.

Dr. Marcus Maurer, Professor of Dermatology and Allergy at Charité – Universitätsmedizin in Berlin and a Principal Investigator in the Phase 3 barzolvolimab studies, highlighted the drug's potential. He stated that barzolvolimab has shown a unique and profound ability to offer rapid, durable, and complete disease control in patients with CSU, regardless of their previous treatment history. He emphasized that advancing this promising agent into late-stage studies is significant for patients and physicians needing better treatment options.

The EMBARQ-CSU1 and EMBARQ-CSU2 trials are randomized, double-blind, placebo-controlled, parallel-group global studies involving approximately 915 patients. These patients will be equally divided to receive either 150 mg of barzolvolimab every four weeks (following a 300 mg loading dose), 300 mg every eight weeks (following a 450 mg loading dose), or a placebo for 52 weeks. After 24 weeks, patients on placebo will be re-randomized to active treatment groups. The primary endpoint of the study is to evaluate the clinical effectiveness of barzolvolimab in reducing urticaria activity (weekly urticaria activity score; UAS7) at Week 12. The study aims to detect a meaningful difference between the active treatment arms and placebo in the overall population and in the subpopulation of patients refractory to omalizumab.

Anthony Marucci, Co-founder, President, and CEO of Celldex Therapeutics, stressed the importance of advancing barzolvolimab into registrational studies to meet the needs of CSU patients. He highlighted the company's commitment to executing these trials seamlessly and providing barzolvolimab for patients, while also exploring its potential in other indications.

Results from a placebo-controlled Phase 2 study in CSU showed that barzolvolimab met the primary endpoint, demonstrating a statistically significant mean change from baseline to week 12 in UAS7 across all dose levels. Secondary and exploratory endpoints, including changes in ISS7 (weekly itch severity score) and HSS7 (weekly hives severity score), were also achieved at week 12, strongly supporting the primary endpoint results. Barzolvolimab provided rapid, durable, and clinically meaningful responses in patients with moderate to severe CSU refractory to antihistamines, including those previously treated with omalizumab. The drug was well tolerated and had a favorable safety profile.

Barzolvolimab is currently being studied in CSU, chronic inducible urticaria (CIndU), prurigo nodularis (PN), and eosinophilic esophagitis (EOE), with additional indications planned for the future, including atopic dermatitis (AD).

Celldex Therapeutics is a clinical-stage biotechnology company focused on developing transformative therapeutics for severe inflammatory, allergic, autoimmune, and other debilitating diseases.