Long-term Efficacy and Safety Extension (LTE) Study of Barzolvolimab in Participants With Chronic Spontaneous Urticaria

August 25, 2026 updated by: Celldex Therapeutics

A Phase 3b Long-term Efficacy and Safety Extension Study of Barzolvolimab in Participants With Chronic Spontaneous Urticaria Who Have Completed CDX0159-12 or CDX0159-13

The purpose of this extension study is to collect long-term efficacy and safety data on barzolvolimab in adult participants with Chronic Spontaneous Urticaria (CSU) who completed the treatment and follow-up periods of the Phase 3 clinical trials.

This study will also fulfill the Celldex commitment to provide post-trial access to participants who have completed the phase 3 studies, where applicable.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

This is a global, multicenter, long-term extension phase 3b study to determine the time to disease worsening or treatment failure in adult participants with Chronic Spontaneous Urticaria (CSU) who completed the treatment and follow-up periods the phase 3 clinical trials.

The study will consist of 2 Groups: Group 1 (Observation Group), comprising participants whose UAS7 score is less than 16 at entry and Group 2 (Barzolvolimab Retreatment Group) comprising participants whose UAS7 score is 16 or greater.

Participation in this trial will last for approximately 52 weeks for participants assigned to Group 1 (Observation Group) and who do not receive barzolvolimab during the trial. Participants assigned to Group 1 who require barzolvolimab rescue during the trial will be in the trial for up to 68 weeks. Participants assigned to Group 2 (Barzolvolimab Retreatment Group), trial participation will last for approximately 68 weeks from the start of treatment (Day 1).

Study Type

Interventional

Enrollment (Estimated)

1370

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Argentina
    • Buenos Aires F.D.
      • CABA, Buenos Aires F.D., Argentina, 1012
        • CONEXA Investigacion Clinica S.A.
      • CABA, Buenos Aires F.D., Argentina, 1406
        • Aprillus Asistencia e Investigacion de Arcis Salud SRL
    • Sante Fe
      • Rosario, Sante Fe, Argentina, 2000
        • Centro respiratorio Infantil
      • Rosario, Sante Fe, Argentina, S2000DEJ
        • Instituto Medico de la Fundacion Estudios Clinicos
      • Rosario, Sante Fe, Argentina, 2000
        • Instituto de Especialidades de la Salud Rosario - Clínica del Tórax
    • Tucumán Province
      • San Miguel de Tucumán, Tucumán Province, Argentina, 4000
        • Clinica Mayo de Urgencias
  • Australia
    • QSL
      • Coorparoo, QSL, Australia, 4151
        • Cornerstone Dermatology
    • Victoria
      • Melbourne, Victoria, Australia, 3004
        • The Alfred Hospital - Kern
  • Belgium
      • Brussels, Belgium, 1200
        • Cliniques universitaires Saint-Luc
  • Bulgaria
      • Dupnitsa, Bulgaria, 2600
        • Medical Centre Asklepii OOD
      • Haskovo, Bulgaria, 6304
        • Medical Center Medtech Services EOOD
      • Razgrad, Bulgaria, 7200
        • Outpatient Clinic for IP for Specialized Outpatient Medical Care in Allergology-Dr.Cholak
      • Sofia, Bulgaria, 1510
        • Medical Center Hera EOOD
      • Sofia, Bulgaria, 1431
        • Diagnostic and Consulting Center Aleksandrovska EOOD
      • Sofia, Bulgaria, 1606
        • University Multiprofile Hospital for Active Treatment and Emergency Medicine N. I. Pirogov EAD
      • Sofia, Bulgaria, 1000
        • Medical Center Iskar EOOD
      • Sofia, Bulgaria, 1756
        • Medical Center Pulmovision
      • Sofia, Bulgaria, 1202
        • The Diagnostic-Consultative Centre Ascendent EOOD
      • Sofia, Bulgaria, 1463
        • Diagnostic Consultative Centre - Focus-5 - LZIP EOOD
  • Canada
      • Québec, Canada, G1W4R4
        • Centre de Recherche Saint-Louis
    • Alberta
      • Edmonton, Alberta, Canada, T6H 4J8
        • VIDA Dermatology
    • Ontario
      • Hamilton, Ontario, Canada, L8L 3C3
        • Lima's Excellence In Allergy And Dermatology Research (Leader) Inc.
      • Markham, Ontario, Canada, L3P 1X3
        • Lynderm Research Inc
      • North Bay, Ontario, Canada, P1B 3Z7
        • North Bay Dermatology Center
      • Toronto, Ontario, Canada, M5G1E2
        • Evidence Based Medical Educator Inc.
      • Windsor, Ontario, Canada, N8X 2G1
        • Joel Liem Medicine Professional Corporation
  • Chile
      • Providencia, Chile, 7500000
        • Enroll SpA - Dr. Manuel Barros Borgono
      • Recoleta, Chile, 8420383
        • Centro Internacional de Estudios Clinicos (CIEC)
      • Santiago, Chile, 8350595
        • Centro de Estudios Clinicos e Investigaciones Medicas CeCim
      • Vitacura, Chile, 7630000
        • Dermacross Clinica Dermatologica
  • Denmark
      • Hellerup, Denmark, 2900
        • Gentofte Hospital
  • France
      • Nantes, France, 44093
        • CHRU Nantes Hôtel Dieu
      • Nice, France, 06202
        • CHU de Nice-Hôpital L'Archet
  • Germany
    • Hesse
      • Darmstadt, Hesse, Germany, 64283
        • Rosenpark Research
    • North Rhine-Westphalia
      • Dülmen, North Rhine-Westphalia, Germany, 48249
        • ProDerma
    • Schleswig-Holstein
      • Kiel, Schleswig-Holstein, Germany, 24148
        • Medizinisches Versorgungszentrum DermaKiel GmbH
  • Greece
      • Athens, Greece, 16121
        • Hospital A. Syggros
    • Attica
      • Chaïdári, Attica, Greece, 12462
        • University General Hospital ''ATTIKON'' - General Hospital of West Attica H AGIA VARVARA
  • India
    • Maharashtra
      • Nagpur, Maharashtra, India, 440009
        • Shree Hospital & Critical Care Centre
      • Nashik, Maharashtra, India, 422101
        • G.S.V.M. Medical College
      • Pune, Maharashtra, India, 411005
        • Oyster & Pearl Hospitals
  • Italy
      • Torino, Italy, 20128
        • Azienda Ospedaliera Ordine Mauriziano Di Torino
  • Lithuania
      • Kaunas, Lithuania, LT-44192
        • CD8 Klinika
  • Malaysia
      • Ipoh, Malaysia, 30450
        • Hospital Raja Permaisuri Bainun
      • Johor Bahru, Malaysia, 81100
        • Hospital Sultan Ismail
      • Kuala Lumpur, Malaysia, 50586
        • Hospital Kuala Lumpur
      • Kuching, Malaysia, 93586
        • Hospital Umum Sarawak
  • Poland
      • Bialystok, Poland, 15-453
        • NZOZ Specjalistyczny Ośrodek Dermatologiczny "DERMAL"
      • Częstochowa, Poland, 42-217
        • Centrum Medyczne Pratia Częstochowa
      • Gdansk, Poland, 80-546
        • Centrum Badan Klinicznych PI-House sp. z o.o.
      • Katowice, Poland, 40-040
        • Synexus Polska Sp. Z O.O. Oddzial W Katowicach
      • Katowice, Poland, 40-081
        • Centrum Medyczne Katowice - PRATIA
      • Krakow, Poland, 30-033
        • Centrum Medyczne ALL-MED Badania Kliniczne
      • Krakow, Poland, 31-011
        • Centrum Nowoczesnych Terapii Dobry Lekarz Sp. z o.o.
      • Lublin, Poland, 20-753
        • Luxderm Specjalistyczny Gabinet Dermatologiczny Dorota Krasowska
      • Oświęcim, Poland, 32-600
        • Medicome Sp. z o.o.
      • Poznan, Poland, 60-185
        • Centrum Medyczne Pratia Poznan
      • Skarżysko-Kamienna, Poland, 26-110
        • Niepubliczny Specjalistyczny ZOZ Puls-Med s.c.
      • Tarnów, Poland, 33-100
        • Alergo-med Ośrodek Badań Klinicznych Spólka z ograniczoną odpowiedzialnością
      • Torun, Poland, 87-100
        • MICS Centrum Medyczne Toruń
      • Warsaw, Poland, 02-953
        • Klinika Ambroziak Dermatologia
      • Warsaw, Poland, 02-677
        • ETG Warszawa Sp. z o.o.
      • Wroclaw, Poland, 50-566
        • Cityclinic Przychodnia Lekarsko Psychologiczna Matusiak Spółka Partnerska
      • Wroclaw, Poland, 54-144
        • EuroMediCare Szpital Specjalistyczny z Przychodnia we Wroclawiu
      • Wroclaw, Poland, 50-414
        • Ginemedica Sp. z o.o.
  • Portugal
      • Aveiro, Portugal, 3814-501
        • ULS da Região de Aveiro, EPE - Hospital Infante D. Pedro
      • Coimbra, Portugal, 3004-561
        • ULS de Coimbra, EPE - Hospitais da Universidade de Coimbra
      • Lisbon, Portugal, 1649-035
        • ULS de Santa Maria,EPE - Hospital de Santa Maria
      • Setúbal, Portugal, 2910-548
        • ULS da Arrábida, EPE - Hospital de São Bernardo
  • South Africa
    • Gauteng
      • Benoni, Gauteng, South Africa, 1501
        • Worthwhile Clinical Trials
      • Newtown, Gauteng, South Africa, 2001
        • Newtown Clinical Research Centre
      • Pretoria, Gauteng, South Africa, 0181
        • About Allergy
      • Pretoria, Gauteng, South Africa, 0157
        • Global Clinical Trials (Pty) Ltd - Pretoria
    • KwaZulu-Natal
      • Durban, KwaZulu-Natal, South Africa, 4001
        • Synapta Clinical Research Centre
    • Western Cape
      • Mowbray, Western Cape, South Africa, 7700
        • University of Cape Town Lung Institute (UCTLI)
  • South Korea
      • Seoul, South Korea, 3080
        • Seoul National University Hospital
      • Seoul, South Korea, 4763
        • Hanyang University Seoul Hospital
      • Suwon, South Korea, 16499
        • Ajou University Hospital
  • Spain
      • Alicante, Spain, 03010
        • Hospital General Universitario Dr. Balmis
      • Barcelona, Spain, 8036
        • Hospital Clinic de Barcelona
      • Barcelona, Spain, 8003
        • Hospital Del Mar
      • Barcelona, Spain, 8035
        • Hospital Universitario Vall d'Hebron
      • Madrid, Spain, 28040
        • Hospital Clinico San Carlos - Lopez Bran
      • Villarreal de Huerva, Spain, 12540
        • Hospital Universitario de La Plana
  • Taiwan
      • Hsinchu, Taiwan, 300
        • National Taiwan University Hospital - Hsin-Chu Branch
      • Kaohsiung City, Taiwan, 833
        • Chang Gung Medical Foundation Kaohsiung Chang Gung Memorial Hospital
      • Kaohsiung City, Taiwan, 813414
        • Kaohsiung Veterans General Hospital
      • Taichung, Taiwan, 404
        • China Medical University Hospital
      • Taipei, Taiwan, 10449
        • Mackay Memorial Hospital
      • Taipei, Taiwan, 10048
        • National Taiwan University Hospital
  • Thailand
      • Khlong Luang, Thailand, 12120
        • Thammasat University Hospital
  • United Kingdom
      • North Finchley, United Kingdom, N12 8BU
        • Velocity Clinical Research, North London
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35244
        • Cahaba Dermatology & Skin Health Center, LLC
    • Arizona
      • Scottsdale, Arizona, United States, 85251
        • Medical Research of Arizona
      • Scottsdale, Arizona, United States, 85260
        • Center for Dermatology & Plastic Surgery - Avacare
    • California
      • Bakersfield, California, United States, 93301
        • Kern Research
      • Laguna Niguel, California, United States, 92677
        • Allergy and Asthma Associates of Southern California - Laguna Niguel - CRN
      • Los Angeles, California, United States, 90045
        • Dermatology Research Associates
      • Los Angeles, California, United States, 90057
        • LA Universal Research Center, Inc.
    • Colorado
      • Colorado Springs, Colorado, United States, 80907
        • Asthma and Allergy Associates
    • Florida
      • Boynton Beach, Florida, United States, 33436
        • Encore Medical Research of Boynton Beach LLC
      • Doral, Florida, United States, 33172
        • Dolphin Medical Research
      • Hialeah, Florida, United States, 33012
        • Direct Helpers Research Center
      • Miami, Florida, United States, 33176
        • Miami Dade Medical Research Institute, LLC
      • Miami Lakes, Florida, United States, 33014
        • Deluxe Health Center
      • Sarasota, Florida, United States, 34239
        • Sarasota Clinical Research
      • St. Petersburg, Florida, United States, 33705
        • GCP, Global Clinical Professionals
      • Tampa, Florida, United States, 33607
        • Advanced Clinical Research Institute (ACRI) - Florida
    • Georgia
      • Columbus, Georgia, United States, 31904
        • Centricity Research Columbus Dermatology
    • Illinois
      • Skokie, Illinois, United States, 60026
        • Endeavor Health
    • Indiana
      • South Bend, Indiana, United States, 46617
        • The South Bend Clinic - Avacare
    • Kentucky
      • Owensboro, Kentucky, United States, 42301
        • Allergy and Asthma Specialists PSC
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • John Hopkins University
      • Wheaton, Maryland, United States, 20902
        • Institute for Asthma and Allergy
    • Michigan
      • Clarkston, Michigan, United States, 48346
        • Michigan Center for Research Co., LLC
      • Ypsilanti, Michigan, United States, 48197
        • Respiratory Medicine Research Institute of Michigan PLC
    • Missouri
      • St Louis, Missouri, United States, 63141
        • Washington University School of Medicine
      • St Louis, Missouri, United States, 63141
        • Midwest Clinical Research
    • Montana
      • Missoula, Montana, United States, 59808
        • Montana Medical Research, Inc.
    • New York
      • New York, New York, United States, 10128
        • Markowitz Medical PLLC dba OptiSkin Medical
    • Ohio
      • Bexley, Ohio, United States, 43209
        • Bexley Dermatology Research
      • Findlay, Ohio, United States, 45840
        • Auni Allergy
      • Toledo, Ohio, United States, 43617
        • Toledo Institute of Clinical Research
      • Toledo, Ohio, United States, 43617
        • Toledo Institute for Clinical Research
    • Oregon
      • Clackamas, Oregon, United States, 97015
        • Portland Allergy and Asthma
    • Rhode Island
      • Johnston, Rhode Island, United States, 02919
        • Clinical Partners LLC
    • Texas
      • Dallas, Texas, United States, 75225
        • Alina Clinical Trials LLC
      • El Paso, Texas, United States, 79912
        • Western Sky Medical Research
      • San Antonio, Texas, United States, 78213
        • Rainey & Finklea San Antonio (RFSA) Dermatology
      • Waco, Texas, United States, 76712
        • Allergy and Asthma Care of Waco
    • Utah
      • Sandy City, Utah, United States, 84093
        • Allergy Associates of Utah

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Written informed consent
  2. Must have successfully completed the preceding phase 3 clinical trials (CDX0159-12 or CDX0159-13).
  3. Both males and females of child-bearing potential must agree to use highly effective contraceptives when receiving barzolvolimab treatment and for 150 days after treatment.
  4. Willing and able to comply with all study requirements and procedures, including completion of a daily symptom electronic diary.

Key Exclusion Criteria:

  1. Active pruritic skin condition in addition to CSU.
  2. Medical condition that would cause additional risk or interfere with study procedures.
  3. Participants without at least one documented UAS7 score from Weeks 64-68 of the CDX0159-12 or CDX0159-13 trials.

There are additional criteria that your study doctor will review with you to confirm you are eligible for the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group 1 Observation Group

Standard of care treatment (at least 2nd generation Type 1 antihistamines [H1AH] with or without other permitted background medications) for 52 weeks.

For participants with worsening disease (UAS7 score of 16 or greater at any time between Weeks 0-24), barzolvolimab will be administered once as a 300 mg subcutaneous injection followed by 150 mg every 4 weeks for up to 52 weeks.
Biological: barzolvolimab
Subcutaneous Administration
Other: Standard of Care
Observational/Standard of Care
Experimental: Group 2 Barzolvolimab Retreatment Group
Barzolvolimab given once as a 300 mg subcutaneous injection followed by 150 mg administered every 4 weeks for 52 weeks
Biological: barzolvolimab
Subcutaneous Administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to disease worsening or treatment failure through Week 52 based on the occurrence of UAS7 (Urticaria Activity Score) of 16 or greater.
Time Frame: From Day 1 (baseline) to Week 52.
The UAS7 is a simple scoring system to evaluate urticaria signs and symptoms. It is based on scoring wheals (hive severity score) and itch (itch severity score) separately on a scale of 0 (no signs/symptoms) to 3 (intense signs/symptoms) over 7 days. The final score is calculated by adding together the daily scores, which can range from 0 to 6, for 7 days. This results in a maximum total score of 42, and a minimum possible score of 0.
From Day 1 (baseline) to Week 52.
Time to disease worsening or treatment failure through Week 52 based on the occurrence of the discontinuation of barzolvolimab in Group 2 due to lack of efficacy or to a treatment related adverse event.
Time Frame: From Day 1 (baseline) to Week 52.
Evaluate duration of efficacy of barzolvolimab on urticaria activity or to a treatment related adverse event.
From Day 1 (baseline) to Week 52.
Time to disease worsening or treatment failure through Week 52 based on the occurrence of first use of strongly confounding prohibited medication (Group 1 or 2) or use of barzolvolimab in Group 1.
Time Frame: From Day 1 (baseline) to Week 52.
Evaluate duration of efficacy of barzolvolimab on urticaria activity leading to initiation of either a confounding prohibited medication (Group 1 or 2) or barzolvolimab in Group 1.
From Day 1 (baseline) to Week 52.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Group 1: Change from baseline in Urticaria Activity Score (UAS7) at Week 26.
Time Frame: From Day 1 (baseline) in phase 3 trial to Week 26.

Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS7).

The UAS7 is a simple scoring system to evaluate urticaria signs and symptoms. It is based on scoring wheals (hive severity score) and itch (itch severity score) separately on a scale of 0 (no signs/symptoms) to 3 (intense signs/symptoms) over 7 days. The final score is calculated by adding together the daily scores, which can range from 0 to 6, for 7 days. This results in a maximum total score of 42, and a minimum possible score of 0.
From Day 1 (baseline) in phase 3 trial to Week 26.
Group 1: Change from baseline in UAS7 at Week 52/End of Study.
Time Frame: From Day 1 (baseline) in phase 3 trial to Week 52/End of Study.

Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS)

The UAS7 is a simple scoring system to evaluate urticaria signs and symptoms. It is based on scoring wheals (hive severity score) and itch (itch severity score) separately on a scale of 0 (no signs/symptoms) to 3 (intense signs/symptoms) over 7 days. The final score is calculated by adding together the daily scores, which can range from 0 to 6, for 7 days. This results in a maximum total score of 42, and a minimum possible score of 0.
From Day 1 (baseline) in phase 3 trial to Week 52/End of Study.
Percentage of Group 1 participants with UAS7 ≤ 6 at week 26.
Time Frame: From Day 1 (baseline) to Week 26.
Group 1: Proportion of participants who maintained at least well-controlled disease (UAS7 ≤ 6) at Week 26.
From Day 1 (baseline) to Week 26.
Percentage of Group 1 participants with UAS7 ≤ 6 at week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Study.
Group 1: Proportion of participants who maintained at least well-controlled disease (UAS7 ≤ 6) at Week 52.
From Day 1 (baseline) to Week 52/End of Study.
Percentage of Group 1 participants with UAS7 = 0 at Day 1 who have UAS7 ≤ 6 at Week 26.
Time Frame: From Day 1 (baseline) to Week 26.
Group 1: Proportion of participants with complete absence of hives and itch (UAS7 = 0) at Day 1 who have well controlled CSU (UAS7 ≤ 6) at Week 26.
From Day 1 (baseline) to Week 26.
Percentage of Group 1 participants with UAS7 = 0 at Day 1 who have UAS7 ≤ 6 at Week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Treatment.
Group 1: Proportion of participants with complete absence of hives and itch (UAS7 = 0) at Day 1 who have well-controlled disease (UAS7 ≤ 6) at Week 52.
From Day 1 (baseline) to Week 52/End of Treatment.
Group 1: Proportion of participants with complete absence of hives and itch (UAS7 = 0 AAS7 = 0) at Day 1 who maintained complete control at Week 26.
Time Frame: From Day 1 (baseline) to Week 26.
Angioedema Activity Score over 7 days [AAS7] describes the effect of angioedema on five categories with 0 being none and 3 being most severe. The final score is calculated by adding together daily scores which can range from 0-15 for 7 days. The resulting maximum score is then 105.
From Day 1 (baseline) to Week 26.
Group 1: Proportion of participants with complete absence of hives and itch (UAS7 = 0 AAS7 = 0) at Day 1 who maintained complete control at Week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Study.
Angioedema Activity Score over 7 days [AAS7] describes the effect of angioedema on five categories with 0 being none and 3 being most severe. The final score is calculated by adding together daily scores which can range from 0-15 for 7 days. The resulting maximum score is then 105.
From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with UAS7 ≤ 6 at Day 1, time to loss of well-controlled disease through Week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with at least well-controlled disease (UAS7 ≤ 6) at Day 1, time to loss of well-controlled disease through Week 52.
From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with UAS7 = 0 at Day 1, time to loss of complete controlled disease through Week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with complete absence of hives and itch (UAS7 = 0) at Day 1, time to loss of complete controlled disease through Week 52.
From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with UAS7 = 0 and AAS7 = 0 at Day 1, time to loss of CSU completely controlled through Week 52.
Time Frame: From Day 1 (baseline) to Week 52/End of Study.
Group 1: Participants with complete controlled CSU (UAS7 = 0 and AAS7 = 0) at Day 1, time to loss of CSU completely controlled through Week 52.
From Day 1 (baseline) to Week 52/End of Study.
Group 2: Change from baseline in UAS7 at Week 12.
Time Frame: From Day 1 (baseline) to Week 12.
Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS7).
From Day 1 (baseline) to Week 12.
Group 2: Change from baseline in UAS7 at Week 24.
Time Frame: From Day 1 (baseline) to Week 24.
Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS7).
From Day 1 (baseline) to Week 24.
Group 2: Change from baseline in UAS7 at Week 52.
Time Frame: From Day 1 (baseline) to Week 52.
Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS7).
From Day 1 (baseline) to Week 52.
Group 2: Change from baseline in UAS7 at Week 68.
Time Frame: From Day 1 (baseline) to Week 68.
Evaluate efficacy of barzolvolimab on urticaria activity as measured by urticaria activity score (UAS7).
From Day 1 (baseline) to Week 68.
Group 2: Percentage of participants with UAS7 ≤ 6 at Week 12.
Time Frame: From Day 1 (baseline) to Week 12.
Group 2: Proportion of participants with at least well-controlled disease (UAS7 ≤ 6) at Week 12.
From Day 1 (baseline) to Week 12.
Group 2: Percentage of participants with UAS7 ≤ 6 at Week 24.
Time Frame: From Day 1 (baseline) to Week 24.
Group 2: Proportion of participants with at least well-controlled disease (UAS7 ≤ 6) at Week 24.
From Day 1 (baseline) to Week 24.
Group 2: Percentage of participants with UAS7 ≤ 6 at Week 52.
Time Frame: From Day 1 (baseline) to Week 52.
Group 2: Proportion of participants with at least well-controlled disease (UAS7 ≤ 6) at Week 52.
From Day 1 (baseline) to Week 52.
Group 2: Percentage of participants with UAS7 ≤ 6 at Week 68.
Time Frame: From Day 1 (baseline) to Week 68.
Group 2: Proportion of participants with at least well-controlled disease (UAS7 ≤ 6) at Week 68.
From Day 1 (baseline) to Week 68.
From Day 1 (baseline) to Week 68.
Time Frame: From Day 1 (baseline) to Week 12.
Group 2: Proportion of participants who achieve complete absence of hives and itch (UAS7 = 0) at Week 12.
From Day 1 (baseline) to Week 12.
Group 2: Percentage of participants with UAS7 = 0 at Week 24.
Time Frame: From Day 1 (baseline) to Week 24.
Group 2: Proportion of participants who achieve complete absence of hives and itch (UAS7 = 0) at Week 24.
From Day 1 (baseline) to Week 24.
Group 2: Percentage of participants with UAS7 = 0 at Week 52.
Time Frame: From Day 1 (baseline) to Week 52.
Group 2: Proportion of participants who achieve complete absence of hives and itch (UAS7 = 0) at Week 52.
From Day 1 (baseline) to Week 52.
Group 2: Percentage of participants with UAS7 = 0 at Week 68.
Time Frame: From Day 1 (baseline) to Week 68.
Group 2: Proportion of participants who achieve complete absence of hives and itch (UAS7 = 0) at Week 68.
From Day 1 (baseline) to Week 68.
Group 1 Incidence of adverse events.
Time Frame: From Day 1 to Week 52.
Group 1: Proportion of participants experiencing adverse events during the study.
From Day 1 to Week 52.
Group 1 Incidence of non-treatment emergent adverse events.
Time Frame: From Day 1 to Week 52.
Group 1: Proportion of participants who never receive barzolvolimab retreatment experiencing non-treatment emergent adverse events.
From Day 1 to Week 52.
Group 1 Incidence of treatment emergent adverse events in participants receiving barzolvolimab retreatment.
Time Frame: From Day 1 to Week 68.
Group 1: Proportion of participants who receive barzolvolimab retreatment experiencing treatment emergent adverse events.
From Day 1 to Week 68.
Group 1 Incidence of treatment emergent adverse events leading to treatment discontinuation.
Time Frame: From Day 1 to Week 68.
Group 1: Proportion of participants who receive barzolvolimab retreatment experiencing treatment emergent adverse events leading to treatment discontinuation during the study.
From Day 1 to Week 68.
Group 2 Incidence of treatment emergent adverse events.
Time Frame: Time Frame: From Day 1 to Week 68.
Group 2: Proportion of participants experiencing treatment emergent adverse events during the study.
Time Frame: From Day 1 to Week 68.
Group 2 Incidence of treatment emergent adverse events leading to treatment discontinuation.
Time Frame: From Day 1 to Week 68.
Group 2: Proportion of participants experiencing treatment emergent adverse events leading to treatment discontinuation during the study.
From Day 1 to Week 68.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Celldex Therapeutics

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 25, 2025

Primary Completion (Estimated)

September 1, 2028

Study Completion (Estimated)

September 1, 2028

Study Registration Dates

First Submitted

November 20, 2025

First Submitted That Met QC Criteria

November 20, 2025

First Posted (Actual)

December 1, 2025

Study Record Updates

Last Update Posted (Actual)

August 27, 2026

Last Update Submitted That Met QC Criteria

August 25, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CDX0159-17

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

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