EMBARQ-CSU LTE
Research type
Research Study
Full 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 (EMBARQ-CSU LTE)
IRAS ID
1013451
Contact name
Science Department
Contact email
Sponsor organisation
Celldex Therapeutics, Inc.
Clinicaltrials.gov Identifier
Research summary
This study is a long-term extension for people with chronic spontaneous urticaria (CSU) who have already completed one of Celldex’s previous studies (CDX0159-12 or CDX0159-13). CSU causes repeated hives, itching and sometimes swelling without a clear trigger. Many people continue to have symptoms even after standard treatments such as antihistamines.
The medicine being studied is barzolvolimab, an antibody designed to block the activity of mast cells, which are involved in causing hives. The purpose of this extension study is to understand how long symptom control lasts, how symptoms may change over time, and how safe long-term treatment is.
Participants will be assigned to one of two groups based on their symptom score at the end of their previous study.
• Group 1 (Observation Group): Participants whose CSU is well controlled will not receive barzolvolimab at the start. They will continue their usual standard care. If their symptoms worsen, they may restart barzolvolimab as rescue treatment.
• Group 2 (Retreatment Group): Participants whose symptoms have returned or worsened will restart barzolvolimab (a loading dose followed by dosing every 4 weeks).The study will look at how many participants keep their symptoms under control, how quickly symptoms return if they do, and how participants respond if barzolvolimab is restarted. Safety will be monitored closely, and an independent committee will periodically review the data.
This study aims to provide important information about the long-term safety and effectiveness of barzolvolimab for people with CSU who previously took part in earlier trials.
REC name
London - West London & GTAC Research Ethics Committee
REC reference
26/LO/0212
Date of REC Opinion
8 May 2026
REC opinion
Further Information Favourable Opinion