Positive 12-Week Barzolvolimab Phase 2 Results in CSU Treatment

Celldex Therapeutics has reported positive outcomes from a Phase 2 clinical trial of barzolvolimab, a monoclonal antibody targeting the receptor tyrosine kinase KIT, which is crucial for mast cell function and survival. The drug is being tested on patients with moderate to severe chronic spontaneous urticaria (CSU) who have not responded to antihistamines, including those with biologic-refractory conditions. The study, which will continue until week 52, has shown significant improvements in urticaria disease activity across various dosages, with rapid onset within two weeks.

Barzolvolimab has demonstrated similar efficacy in patients who have previously received omalizumab and those who have not, highlighting its unique mechanism of action. The drug has also shown a favorable safety profile, with most adverse events being mild to moderate. The most common side effects included urticaria/CSU, hair color changes, and neutropenia/ANC decrease. The rate of infections was comparable between the treatment and placebo groups.

The Phase 2 trial is a randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of multiple dosing regimens of barzolvolimab in CSU patients who continue to experience symptoms despite antihistamine therapy. The study's primary endpoint is the mean change in the weekly urticaria activity score (UAS7) from baseline to week 12. Secondary endpoints encompass assessments of safety, clinical activity, itch severity, and hives severity.

The positive results were presented by Dr. Marcus Maurer at the American Academy of Allergy, Asthma & Immunology Annual Meeting 2024. Dr. Maurer emphasized the potential of barzolvolimab to provide significant relief to patients suffering from CSU, a condition characterized by persistent hives or wheals without identifiable triggers. Currently, there are limited treatment options for CSU patients, especially those not adequately controlled by omalizumab.

Anthony S. Marucci, President and CEO of Celldex Therapeutics, expressed excitement about the results and the company's plans to initiate a Phase 3 program for CSU in the coming summer. The company is also looking forward to sharing the 52-week data later in the year.

The study involved 208 patients who were randomly assigned to receive subcutaneous injections of barzolvolimab at varying doses or placebo. The results showed that barzolvolimab achieved the primary efficacy endpoint with a statistically significant mean change from baseline to week 12 in UAS7 compared to placebo at all dose levels. Secondary and exploratory endpoints also supported the primary results, indicating rapid, durable, and clinically meaningful responses in patients with moderate to severe CSU.

Celldex Therapeutics is a clinical-stage biotechnology company focused on developing transformative therapeutics for severe inflammatory, allergic, autoimmune, and other devastating diseases. The company's pipeline includes antibody-based therapeutics that engage the human immune system or directly affect critical pathways to improve patient outcomes.