Clinical trial Recruiting at 4 sites Phase 1 Interventional Ages 18 to 75

GTX-B001 in healthy people and adults with chronic inducible urticaria

Official title: A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose Tolerability, Pharmacokinetic, Pharmacodynamic, and Preliminary Efficacy Trial of GTX-B001 in Healthy Volunteers (Part A) and Patients With Chronic Inducible Urticaria (Part B)

Run by Granular Therapeutics Limited · NCT07181369 · Data updated 2026-11-12

This will test a single intravenous dose of GTX-B001, a bispecific antibody, in healthy volunteers and in adults with chronic inducible urticaria (cold urticaria or symptomatic dermographism) who still have symptoms despite antihistamines.

More Healthy Subjects (HS) trials

Quick facts

PhasePhase 1
Study typeInterventional
Ages18 Years to 75 Years
SexAll
Enrollment72 (estimated)
SponsorGranular Therapeutics Limited
Industry-sponsored
Drugs / interventionsinfliximab, adalimumab, omalizumab, dupilumab, ligelizumab, methotrexate, cyclophosphamide
Locations5 sites (Berlin and 4 other locations)
StatusRecruiting
StartedOctober 6, 2025
Main results expectedAugust 2027
Study endsAugust 2027
Registry record updatedOctober 30, 2026
Trial IDNCT07181369 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are adults (18–55 for healthy volunteers; 18–75 for patients) with confirmed cold urticaria or symptomatic dermographism who remain symptomatic despite second‑generation H1 antihistamines.

Probably not a fit

People with other types of urticaria, well-controlled symptoms on current therapy, serious uncontrolled medical conditions, or who cannot attend in-person visits are unlikely to benefit or be eligible.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

GTX-B001 is a humanized bispecific antibody designed to bind c-Kit and CD203c on mast cells to limit their activation. This randomized, double-blind, placebo-controlled, first-in-human Phase 1 study administers a single IV dose and follows participants for 12 weeks to characterize safety, pharmacokinetics, and pharmacodynamics. Part A will enroll about 48 healthy adults across five ascending dose cohorts, while Part B will enroll about 24 symptomatic patients across two ascending cohorts to also explore preliminary efficacy. Patients in Part B must have positive provocation tests (TempTest for cold urticaria or FricTest for symptomatic dermographism) and inadequate control on second‑generation H1 antihistamines.

Why it matters

Potential benefit: If successful, GTX-B001 could offer a new targeted treatment that reduces mast-cell–driven hives and itching in people with chronic inducible urticaria.

How similar studies have gone: Mast-cell–directed and anti-IgE therapies have helped some urticaria patients, but this c-Kit/CD203c bispecific antibody is a novel first-in-human approach and has not yet been tested in people.

Who can join: the full rules

Show full inclusion / exclusion criteria
Key inclusion Criteria (Part A):

* The subject is between 18 and 55 years of age (both inclusive) at the date of screening.
* The subject is in good general health based on the medical history, physical examination and the results of vital signs, electrocardiogram and clinical laboratory, as judged by the investigator.

Key inclusion Criteria (Part B):

* The subject is between 18 and 75 years of age (both inclusive) at the date of screening
* A history of signs and/or symptoms of ColdU or SD experienced ≥ 3 months prior to screening.
* For ColdU patients, a positive provocation test during screening and baseline, using the TempTest® device.
* For SD patients, a positive provocation test with at least 3 pins during screening and baseline, using the FricTest® device.
* Inadequate control of ColdU or SD by second generation H1-antihistamine (sgAH) as defined as the presence of itch and hives following a trigger (e.g. cold or scratching, respectively) within the last 6 weeks prior to screening in spite of use of a sgAH.
* A Urticaria Control Test (UCT) score of \< 12 at screening.

Key exclusion Criteria (Parts A \& B):

* Presence of any clinically significant illness, such as cardiovascular, neurologic, pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, or endocrine disease or disorder that would interfere with the patient's safety or the interpretation of trial results in the judgment of the investigator.
* Treatment with an investigational drug or intervention for any condition within three months of screening, or concurrent participation in another clinical trial in which an investigational drug is administered.
* Treatment with immunomodulating therapy (e.g., intravenous or intramuscular immunoglobulins, systemic corticosteroids, cyclosporine, methotrexate, dapsone, cyclophosphamide, tacrolimus, mycophenolate mofetil, hydroxychloroquine, infliximab, adalimumab, etanercept, etc.) within 4 weeks (or 5 half-lives, whichever is longer) prior to screening.
* Use of any monoclonal antibody or therapeutic protein within 4 weeks (or 5 half-lives, whichever is longer) prior to screening.
* History of anaphylaxis, autoimmune disorders requiring more than topical medication, or asthma requiring regular use of inhaled medication within the past 5 years, unless, in the opinion of the Investigator, the condition is not considered clinically significant and is unlikely to affect subject safety or study outcomes.

Additionally for Part B:

* Disease with symptoms of urticaria or angioedema other than Chronic Urticaria (CU), for example urticaria vasculitis, erythema multiforme, mastocytosis, or drug-induced urticaria. Patients with concomitant Chronic Spontaneous Urticaria (CSU) or other forms of Chronic Inducible Urticaria (CIndU) are eligible provided that symptoms at screening are consistent with ColdU or SD and that ColdU or SD is the dominant form of CU.
* Any other skin disease associated with chronic itching that might influence in the investigators' opinion of the study evaluations and results, e.g., atopic dermatitis, bullous pemphigoid, dermatitis herpetiformis, or psoriasis.
* Receipt of any biologic therapy for urticaria control (e.g. omalizumab, dupilumab, ligelizumab, etc.) within three months of screening (whether on-label or off-label).

Where it's running

  • Charite Universitaetsmedizin Berlin
    Berlin, Germany
    Recruiting
  • Dermatologische Praxis
    Halle, Germany
    Recruiting
  • Universitaetsklinikum Giessen und Marburg GmbH
    Marburg, Germany
    Recruiting
  • Universitatsklinikum Münster
    Münster, Germany
    Recruiting
  • Charité Research Organization gmbh
    Berlin, Germany
    Active not recruiting

Similar studies

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How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.