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Study on Barzolvolimab for Patients with Chronic Spontaneous Urticaria Unresponsive to H1 Antihistamines

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a medication called Barzolvolimab in patients with a condition known as Chronic Spontaneous Urticaria. Chronic Spontaneous Urticaria is a skin condition characterized by the sudden appearance of itchy hives or welts on the skin, which can occur without a known cause. The study aims to evaluate how well Barzolvolimab works in reducing the symptoms of this condition compared to a placebo. Barzolvolimab is a type of medication known as a monoclonal antibody, which is designed to target specific proteins in the body that may be involved in causing the symptoms of urticaria.

Participants in the study will receive either Barzolvolimab or a placebo, which is a substance that looks like the medication but does not contain any active ingredients. The study will last for several weeks, during which participants will receive regular doses of the medication or placebo. Throughout the study, participants will be monitored to assess changes in their urticaria symptoms, particularly focusing on the reduction of hives and itching. The main goal is to see if Barzolvolimab can significantly improve the condition compared to the placebo by the end of the study period.

The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving the actual medication and who is receiving the placebo. This helps ensure that the results are unbiased and reliable. The trial will also involve regular check-ups and assessments to track the progress and any potential side effects. The findings from this study could provide valuable insights into the effectiveness of Barzolvolimab as a treatment option for those suffering from Chronic Spontaneous Urticaria.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes verifying a diagnosis of chronic spontaneous urticaria (CSU) for at least 6 months and ensuring symptoms persist despite treatment with H1 antihistamines.

    Participants must have a UAS7 score of 16 or higher and an ISS7 score of 8 or higher during the week before randomization.

  2. Step 2

    Randomization

    Participants are randomly assigned to receive either barzolvolimab or a placebo. The placebo is identical in appearance but contains no active medication.

    The study is double-blind, meaning neither participants nor researchers know who receives the active medication or placebo.

  3. Step 3

    Treatment administration

    The treatment involves subcutaneous injections. Participants receive either barzolvolimab or placebo injections according to the study schedule.

    The frequency and dosage of the injections are determined by the study protocol and are administered by healthcare professionals.

  4. Step 4

    Symptom monitoring

    Participants are required to maintain a daily symptom diary throughout the study. This includes recording any changes in symptoms and overall health.

    Regular assessments are conducted to monitor the effectiveness of the treatment, focusing on changes in the UAS7 score.

  5. Step 5

    Evaluation at week 12

    At week 12, a primary evaluation is conducted to assess the change in the UAS7 score from baseline.

    Secondary evaluations include changes in ISS7 and HSS7 scores, and the percentage of participants achieving a UAS7 score of 0.

  6. Step 6

    Long-term follow-up

    Participants continue to be monitored for changes in symptoms at weeks 4, 12, and 24.

    The study aims to determine the long-term efficacy and safety of barzolvolimab in treating CSU.

Who can join the trial?

5 criteria

  • Read, understood, and provided written informed consent. This means you agree to participate after the study has been explained to you. If applicable, you also need to authorize the Health Insurance Portability and Accountability Act (HIPAA), which is a law that protects your health information.
  • Be a male or female who is 18 years of age or older at the time of signing the informed consent.
  • Have a diagnosis of **Chronic Spontaneous Urticaria (CSU)** for at least 6 months before the screening. CSU is a condition where you have hives that appear without a known cause.
  • Have CSU that does not respond to a stable dose of a second-generation **H1 antihistamine (H1AH)**. This means you have had itchy hives with or without swelling for at least 6 weeks before the screening, even while taking H1AH. You must have been on a stable dose of this medication for at least 4 weeks before joining the study, and it should remain stable during the study. Your **Urticaria Activity Score (UAS7)**, which measures the severity of your hives, should be 16 or higher, and your **Itch Severity Score (ISS7)** should be 8 or higher during the week before joining the study.
  • Be willing and able to follow all study requirements and procedures, including keeping a daily symptom diary during the screening and throughout the study.

Who cannot join the trial?

4 criteria

  • Having other medical conditions that cause symptoms similar to hives, such as urticarial vasculitis (inflammation of the blood vessels that causes hives), erythema multiforme (a skin reaction that causes red or purple spots), cutaneous mastocytosis (a condition where too many specialized immune cells build up in the skin), autoimmune syndromes like Schnitzler Syndrome (a rare disease where the immune system attacks the body, causing hives and fever), or angioedema (deep swelling under the skin, which can be inherited or caused by a lack of certain proteins in the blood).
  • Having chronic hives that are primarily triggered by specific external factors, such as dermographism (hives caused by skin scratching or pressure), or hives triggered by cold, heat, sunlight, pressure, water, sweat, or contact with certain substances.
  • Having any other active skin diseases that cause pruritus (severe itching) which might make it difficult for doctors to accurately measure your hives, such as atopic dermatitis (eczema), psoriasis (a condition causing red, scaly patches), bullous pemphigoid (a condition that causes large blisters), dermatitis herpetiformis (an itchy, blistering skin rash), prurigo nodularis (a condition causing very itchy bumps), or chronic pruritus (long-term itching with no known cause).
  • Having previously taken barzolvolimab or any other anti-KIT therapy (medicines that target a specific protein called KIT to control immune cell activity).
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Investigated drugs

Barzolvolimab is a medication being studied for its potential to help patients with chronic spontaneous urticaria, a condition characterized by persistent hives and itching. This trial aims to determine if barzolvolimab can effectively reduce the symptoms of urticaria in patients who continue to experience symptoms despite treatment with H1 antihistamines. The study will assess the improvement in urticaria activity over a 12-week period.

What is already known about the treatment

Barzolvolimab – Barzolvolimab is administered via injection and is currently being studied in clinical trials for its effectiveness in treating chronic spontaneous urticaria, a condition characterized by persistent hives. The medication is in the phase 3 stage of clinical trials, indicating it is being tested for safety and efficacy in a larger group of patients. It is designed to reduce urticaria activity, as measured by a weekly urticaria activity score. Barzolvolimab works by targeting specific pathways involved in the inflammatory response, helping to alleviate symptoms in patients who do not respond to standard H1 antihistamine treatments. It is classified as an investigational drug within the field of immunology.

Investigated diseases

Chronic Spontaneous Urticaria – This is a skin condition characterized by the sudden appearance of itchy hives or welts on the skin, which can occur without an obvious trigger. The hives can vary in size and may appear anywhere on the body. They often come and go, sometimes disappearing within a few hours only to reappear later. The condition is considered chronic when the hives persist for six weeks or longer. It is not associated with any specific allergen and can be unpredictable in its occurrence. The exact cause is often unknown, but it may involve the immune system reacting inappropriately.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-513208-32-00Protocol codeCDX0159-12Estimated enrolment1 203 patientsSponsorCelldex Therapeutics Inc.

sourced from the EU Clinical Trials Register and site verification

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