Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruiting

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

Verified siteRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

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

This clinical trial is focused on studying a condition known as Chronic Spontaneous Urticaria, which is a type of hives that appear without a known cause and can persist for a long time. The study is testing a treatment called Barzolvolimab, also known by its code name CDX-0159. This treatment is being compared to a placebo to see if it can help reduce the symptoms of urticaria, such as itchy welts on the skin, in patients who have not found relief with standard antihistamine treatments.

The purpose of the study is to evaluate how effective and safe Barzolvolimab is in reducing the activity of urticaria. Participants in the study will receive either the treatment or a placebo and will be monitored over a period of time to assess changes in their symptoms. The study will involve regular check-ups and assessments to track the progress of the condition and the effects of the treatment.

Throughout the study, participants will be asked to keep a daily diary of their symptoms and attend scheduled visits to monitor their health and the impact of the treatment. The main goal is to see if Barzolvolimab can significantly reduce the severity of urticaria symptoms by the end of the study period, which is set at 12 weeks. This research aims to provide new insights into managing Chronic Spontaneous Urticaria for those who have not responded well to existing treatments.

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

    Joining the study

    Upon joining the study, the participant provides written informed consent after understanding the study's nature.

    Eligibility is confirmed based on criteria such as age (18 years or older), diagnosis of chronic spontaneous urticaria (CSU) for at least 6 months, and symptoms despite antihistamine treatment.

  2. Step 2

    Screening period

    During the screening period, the participant maintains a stable dose of a second-generation H1 antihistamine for at least 4 weeks.

    A daily symptom diary is completed to record urticaria activity and other symptoms.

  3. Step 3

    Randomization

    Participants are randomly assigned to receive either barzolvolimab or a placebo.

    The study is double-blind, meaning neither the participant nor the researchers know which treatment is being administered.

  4. Step 4

    Treatment phase

    The treatment involves subcutaneous injections of barzolvolimab or placebo.

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

  5. Step 5

    Assessment period

    The primary goal is to evaluate the change in urticaria activity score (UAS7) at Week 12.

    Secondary assessments include changes in other symptom scores and the percentage of participants achieving specific symptom reductions.

  6. Step 6

    Follow-up

    Participants continue to be monitored for changes in symptoms and any side effects.

    The study is expected to conclude by July 2027, with ongoing assessments throughout the trial duration.

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 the study starts, and it should remain stable during the study. Your **Urticaria Activity Score (UAS7)**, which measures the severity of your hives over a week, should be 16 or higher, and your **Itch Severity Score (ISS7)** should be 8 or higher during the week before the study starts.
  • 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?

10 criteria

  • Patients who have a history of severe allergic reactions to any of the study medications.
  • Patients who are currently participating in another clinical trial.
  • Patients who have a significant medical condition that could interfere with the study, such as uncontrolled diabetes or heart disease.
  • Patients who are pregnant or breastfeeding.
  • Patients who have used certain medications that could affect the study results within a specific time frame before the study starts.
  • Patients who have a history of drug or alcohol abuse.
  • Patients who have a mental health condition that could affect their ability to participate in the study.
  • Patients who have had a recent surgery or are planning to have surgery during the study period.
  • Patients who have an active infection that requires treatment.
  • Patients who have been diagnosed with cancer within the past five years, except for certain types of skin cancer.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

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 medication is being tested to see if it can reduce the symptoms of urticaria in patients who have not found relief with standard H1 antihistamine treatments. The goal is to determine if barzolvolimab can effectively decrease the activity of urticaria, as measured by a specific scoring system over a 12-week period.

What is already known about the treatment

Barzolvolimab – Barzolvolimab is administered through an injection, typically under the skin. It is currently being studied in clinical trials for its effectiveness in treating chronic spontaneous urticaria, a condition characterized by persistent hives. The medication works by targeting specific molecules in the immune system to reduce inflammation and alleviate symptoms. It is classified as a monoclonal antibody, which is a type of protein designed to interact with specific targets in the body.

Investigated diseases

Chronic Spontaneous Urticaria – This is a skin condition characterized by the sudden appearance of itchy hives or welts that persist for six weeks or longer without an identifiable cause. The hives can vary in size and may appear anywhere on the body, often changing shape and location. The condition is called "spontaneous" because the hives occur without a known trigger. It can cause significant discomfort due to itching and swelling. The symptoms may fluctuate in intensity and can sometimes be accompanied by angioedema, which is swelling beneath the skin. The exact cause is often unknown, but it may involve an immune system response.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-513210-36-00Protocol codeCDX0159-13Estimated enrolment1 389 patientsSponsorCelldex Therapeutics Inc.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.