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Enrolling by invitationPhase 3

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

Key facts

Who runs it
Celldex Therapeutics
Where
Bakersfield, Baltimore, Bexley, Birmingham, Boynton Beach, Caledonia, Clackamas, Clarkston, Colorado Springs, Columbus, Dallas, Doral, El Paso, Findlay, Hialeah, Johnston, Laguna Niguel, Los Angeles, Margate, Miami, Miami Lakes, Missoula, Murray, New York, Ocean City, Omaha, Owensboro, Rockville, San Antonio, Sandy City, Sarasota, Scottsdale, Skokie, South Bend, St Louis, St. Petersburg, Tampa, Toledo, Waco, West Valley City, Wheaton, and Ypsilanti, United StatesSee the 45 sitesAlso in 29 other countries, 156 sites
Trial code
Status
Enrolling by invitation
Phase
Phase 3
People taking part
1,370 people, planned
Started
25 Nov 2025
Expected to end
Sept 2028
Type of study
Interventional, 2 groups
Treatments tested
  • barzolvolimab
  • Standard of Care
Record updated
2 November 2026

Who can take part

Age
18 years and older
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 7 criteriaShow less

Who can take part

  • Written informed consent
  • Must have successfully completed the preceding phase 3 clinical trials (CDX0159-12 or CDX0159-13)
  • 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
  • Willing and able to comply with all study requirements and procedures, including completion of a daily symptom electronic diary

Who cannot take part

  • Active pruritic skin condition in addition to CSU
  • Medical condition that would cause additional risk or interfere with study procedures
  • 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

Where in United States

Also in 29 other countries, 156 sites

  • Kern ResearchBakersfield, United StatesEnrolling by invitation
  • John Hopkins UniversityBaltimore, United StatesEnrolling by invitation
  • Bexley Dermatology ResearchBexley, United StatesEnrolling by invitation
  • Cahaba Dermatology & Skin Health Center, LLCBirmingham, United StatesEnrolling by invitation
  • Encore Medical Research of Boynton Beach LLCBoynton Beach, United StatesEnrolling by invitation
  • The Derm Institute of West MichiganCaledonia, United StatesEnrolling by invitation
  • Portland Allergy and AsthmaClackamas, United StatesEnrolling by invitation
  • Michigan Center for Research Co., LLCClarkston, United StatesEnrolling by invitation
  • Asthma and Allergy AssociatesColorado Springs, United StatesEnrolling by invitation
  • Centricity Research Columbus DermatologyColumbus, United StatesEnrolling by invitation
  • Alina Clinical Trials, LLC.Dallas, United StatesEnrolling by invitation
  • Dolphin Medical ResearchDoral, United StatesEnrolling by invitation
  • Western Sky Medical ResearchEl Paso, United StatesEnrolling by invitation
  • Auni AllergyFindlay, United StatesEnrolling by invitation
  • Direct Helpers Research CenterHialeah, United StatesEnrolling by invitation
  • Clinical Partners LLCJohnston, United StatesEnrolling by invitation
  • Allergy and Asthma Associates of Southern California - Laguna Niguel - CRNLaguna Niguel, United StatesEnrolling by invitation
  • Dermatology Research AssociatesLos Angeles, United StatesEnrolling by invitation
  • LA Universal Research Center, Inc.Los Angeles, United StatesEnrolling by invitation
  • Gsi Clinical ResearchMargate, United StatesEnrolling by invitation
  • Miami Dade Medical Research Institute, LLCMiami, United StatesEnrolling by invitation
  • Deluxe Health CenterMiami Lakes, United StatesEnrolling by invitation
  • Montana Medical Research, IncMissoula, United StatesEnrolling by invitation
  • University of Utah Midvalley DermatologyMurray, United StatesEnrolling by invitation
  • Markowitz Medical PLLC dba OptiSkin MedicalNew York, United StatesEnrolling by invitation
  • Allergy Partners of NJ, PCOcean City, United StatesEnrolling by invitation
  • Skin Specialists, PC dba Schlessinger MDOmaha, United StatesEnrolling by invitation
  • Allergy and Asthma Specialists PSCOwensboro, United StatesEnrolling by invitation
  • DermAssociates, LLCRockville, United StatesEnrolling by invitation
  • Rainey & Finklea San Antonio (RFSA) DermatologySan Antonio, United StatesEnrolling by invitation
  • Allergy Associates of UtahSandy City, United StatesEnrolling by invitation
  • Sarasota Clinical ResearchSarasota, United StatesEnrolling by invitation
  • Center for Dermatology & Plastic Surgery - AvacareScottsdale, United StatesEnrolling by invitation
  • Medical Research of ArizonaScottsdale, United StatesEnrolling by invitation
  • Endeavor HealthSkokie, United StatesEnrolling by invitation
  • The South Bend Clinic - AvacareSouth Bend, United StatesEnrolling by invitation
  • Midwest Clinical ResearchSt Louis, United StatesEnrolling by invitation
  • Washington University School of MedicineSt Louis, United StatesEnrolling by invitation
  • GCP, Global Clinical ProfessionalsSt. Petersburg, United StatesEnrolling by invitation
  • Advanced Clinical Research Institute (ACRI) - FloridaTampa, United StatesEnrolling by invitation
  • Toledo Institute for Clinical ResearchToledo, United StatesEnrolling by invitation
  • Allergy and Asthma Care of WacoWaco, United StatesEnrolling by invitation
  • Kalo Clinical ResearchWest Valley City, United StatesEnrolling by invitation
  • Institute for Asthma and AllergyWheaton, United StatesEnrolling by invitation
  • Respiratory Medicine Research Institute of Michigan, PLCYpsilanti, United StatesEnrolling by invitation

About the trial

What the trial wants to find out

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.

Read full original descriptionShow less

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

The 2 groups in the trial

  • Group 1 Observation GroupTreatment being tested

    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.

    Treatment: barzolvolimab and Standard of Care

  • Group 2 Barzolvolimab Retreatment GroupTreatment being tested

    Barzolvolimab given once as a 300 mg subcutaneous injection followed by 150 mg administered every 4 weeks for 52 weeks

    Treatment: barzolvolimab

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
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
Record updated
2 November 2026