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

NCT07256392 | Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: CDX0159-17
• Study Type: interventional
• Target: 1,370
• Locations: 3 countries
• Sites: 20

Brief Summary

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.

Conditions

Chronic Spontaneous Urticaria

Keywords

CDX-0159; barzolvolimab; chronic spontaneous urticaria; CSU; urticaria activity score; itch severity score

Outcome Measures

Primary Outcomes (3)

• Time to disease worsening or treatment failure through Week 52 based on the occurrence of UAS7 (Urticaria Activity Score) of 16 or greater.

  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.

  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.

  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 Outcomes (29)

• Group 1: Change from baseline in Urticaria Activity Score (UAS7) at Week 26.

  From Day 1 (baseline) in phase 3 trial to Week 26.

• Group 1: Change from baseline in UAS7 at Week 52/End of Study.

  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.

  From Day 1 (baseline) to Week 26.

• Percentage of Group 1 participants with 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.

  From Day 1 (baseline) to Week 26.

Study Arms (2)

Group 1 Observation Group

EXPERIMENTAL

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; Other: Standard of Care

Group 2 Barzolvolimab Retreatment Group

EXPERIMENTAL

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

Biological: barzolvolimab

Interventions

barzolvolimab BIOLOGICAL

Subcutaneous Administration

Group 1 Observation Group; Group 2 Barzolvolimab Retreatment Group

Standard of Care OTHER

Observational/Standard of Care

Group 1 Observation Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Celldex Therapeutics: lead

Study Sites (20)

Cahaba Dermatology & Skin Health Center, LLC

Birmingham, Alabama, 35244, United States

RECRUITING

Center for Dermatology & Plastic Surgery - Avacare

Scottsdale, Arizona, 85260, United States

RECRUITING

Dermatology Research Associates

Los Angeles, California, 90045, United States

RECRUITING

LA Universal Research Center, Inc.

Los Angeles, California, 90057, United States

RECRUITING

Encore Medical Research of Boynton Beach LLC

Boynton Beach, Florida, 33436, United States

RECRUITING

Direct Helpers Research Center

Hialeah, Florida, 33012, United States

RECRUITING

Deluxe Health Center

Miami Lakes, Florida, 33014, United States

RECRUITING

Sarasota Clinical Research

Sarasota, Florida, 34239, United States

RECRUITING

Advanced Clinical Research Institute (ACRI) - Florida

Tampa, Florida, 33607, United States

RECRUITING

Centricity Research Columbus Dermatology

Columbus, Georgia, 31904, United States

RECRUITING

Endeavor Health

Skokie, Illinois, 60026, United States

RECRUITING

The South Bend Clinic - Avacare

South Bend, Indiana, 46617, United States

RECRUITING

Institute for Asthma and Allergy

Wheaton, Maryland, 20902, United States

RECRUITING

Respiratory Medicine Research Institute of Michigan PLC

Ypsilanti, Michigan, 48197, United States

RECRUITING

Michigan Center for Research Co., LLC (or Profound Research LLC at Clarkson Medical Group as listed in Suvoda)

Clarkson, Missouri, 48346, United States

RECRUITING

Montana Medical Research, Inc.

Missoula, Montana, 59808, United States

RECRUITING

Bexley Dermatology Research

Bexley, Ohio, 43209, United States

RECRUITING

Toledo Institute for Clinical Research

Toledo, Ohio, 43617, United States

RECRUITING

Cornerstone Dermatology

Coorparoo, QSL, 4151, Australia

RECRUITING

EuroMediCare Szpital Specjalistyczny z Przychodnia we Wroclawiu

Wroclaw, 54-144, Poland

RECRUITING

MeSH Terms

Conditions

Chronic Urticaria

Interventions

Standard of Care

Condition Hierarchy (Ancestors)

Urticaria; Skin Diseases, Vascular; Skin Diseases; Skin and Connective Tissue Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Quality Indicators, Health Care; Quality of Health Care; Health Services Administration; Health Care Quality, Access, and Evaluation

Central Study Contacts

Celldex Therapeutics

CONTACT

844-723-9363; clinicaltrials@celldex.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 20, 2025
• First Posted: December 1, 2025
• Study Start: November 25, 2025
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028
• Last Updated: May 1, 2026

Record last verified: 2026-04

Locations

AU (1); PL (1); US (18)