Celldex presents 52 week results from barzolvolimab Phase 2 study

Celldex Therapeutics announced new data demonstrating sustained and deepening disease efficacy and a well tolerated safety profile over a 52 week treatment period for barzolvolimab in chronic spontaneous urticaria, an immune-related condition driven by mast cell activation. Barzolvolimab specifically targets mast cells by binding the receptor tyrosine kinase KIT with high specificity and potently inhibiting its activity, which is required for mast cell function and survival. The data are bring presented today by Dr. Martin Metz, Professor of Dermatology and Allergy at Charite – Universitatsmedizin in Berlin in a late breaking oral presentation at the EADV Congress 2024. The Company previously announced that this Phase 2 study of barzolvolimab in patients with moderate to severe CSU refractory to antihistamines, including patients with biologic-refractory disease, met its primary endpoint-a significant improvement in UAS7 compared to placebo at 12 weeks-across all dose groups tested. New long-term data from the Phase 2 study of barzolvolimab assessed at 52 weeks: Improvements in UAS7, previously shown to be statistically significantly vs placebo at Week 12, were noted as early as week 1 and were sustained or deepened at Week 52. At Week 16, patients receiving low dose barzolvolimab or placebo were transitioned to barzolvolimab 150 mg or 300 mg; after crossover, these patients experienced similar clinically meaningful disease response as the rest of the study population. 71% of patients treated with barzolvolimab 150 mg Q4W and 52% of patients treated with 300 mg Q8W had a complete response at Week 52. These responses were observed early and sustained through 52 weeks. 74% of patients treated with barzolvolimab 150 mg Q4W and 68% of patients treated with 300 mg Q8W had well controlled disease at Week 52. These robust responses were observed regardless of prior omalizumab experience. Barzolvolimab was well tolerated with a favorable safety profile through 52 weeks of treatment. Most adverse events were grade 1, mechanism related and expected to be reversible. The most common treatment emergent adverse events occurring in greater than 10% of barzolvolimab treated patients were hair color changes, neutropenia, urticaria, skin hypopigmentation and nasopharyngitis. Neutrophil counts did not decline further with continued dosing and there was no association between infections and neutropenia. The hypopigmentation was observed with longer term exposure and did not lead to treatment discontinuation. Adverse events were not dose dependent. An e-Poster entitled “Barzolvolimab treatment improves quality of life and urticaria control in patients with chronic spontaneous urticaria: Results from a Phase 2 trial” is available at EADV in the e-poster area. These data are from the 12 week analysis. 67% and 57% of patients treated with 150 mg Q4W or 300 mg Q8W, respectively, reported improvement of CSU and their quality of life. The majority of patients treated with 150 mg Q4W or 300 mg Q8W achieved well-controlled urticaria. Findings were similar for patients with prior omalizumab experience.