A Phase 1 Study of GTX-B001 in Healthy Subjects and Patients With Chronic Inducible Urticaria

NCT ID: NCT07181369

Last Updated: 2026-01-30

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE1
• Total Enrollment: 72 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-10-06
• Study Completion Date: 2027-08-31

Brief Summary

This is a first-in-human study aimed at determining the safety of a single dose of GTX-B001 in healthy participants and in people with chronic inducible urticaria.

Detailed Description

GTX-B001 is a humanized bispecific antibody than binds with one arm to a protein called c-Kit and with the second arm to a protein called CD203c, both expressed on mast cells.

This study is a randomized, double-bind, placebo-controlled phase 1 study evaluating the safety, pharmacokinetics and pharmacodynamics of a single dose of GTX-B001 in healthy participants (Part A) and in patients with chronic inducible urticaria (cold urticaria and symptomatic dermographism) who remain symptomatic despite treatment with antihistamines (Part B). In part B, the preliminary efficacy of GTX-B001 on the signs and symptoms of chronic inducible urticaria will also be evaluated.

48 healthy participants are estimated to be enrolled in part A in five ascending cohorts, while 24 patients with chronic inducible urticaria are estimated to be enrolled in Part B in two ascending cohorts.

Potential participants will be screened for up to 4 weeks prior to enrollment. GTX-B001 will be administered intravenously on Day 1 to randomized participants who will be followed for 12 weeks post-treatment.

Participants will be required to attend a total of 9 visits including the screening visit.

Conditions

Healthy Subjects; Cold Urticaria; Symptomatic Dermographism; Chronic Inducible Urticaria

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SEQUENTIAL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Part A (HV) - GTX-B001

Healthy participants will receive a single dose of GTX-B001

Group Type: EXPERIMENTAL

GTX-B001

Intervention Type: DRUG

Single infusion of one of up to five dosages of GTX-B001

Part A (HV) - Normal Saline

Healthy participants assigned to receive placebo will receive a single dose of normal saline

Group Type: PLACEBO_COMPARATOR

Normal Saline

Intervention Type: DRUG

Single infusion of normal saline

Part B (ColdU/SD) - GTX-B001

Patients with cold urticaria or symptomatic dermographism will receive a single dose of GTX-B001

Group Type: EXPERIMENTAL

GTX-B001

Intervention Type: DRUG

Single infusion of one of up to five dosages of GTX-B001

Part B (ColdU/SD) - Normal Saline

Patients with cold urticaria or symptomatic dermographism assigned to receive placebo will receive a single dose of normal saline

Group Type: PLACEBO_COMPARATOR

Normal Saline

Intervention Type: DRUG

Single infusion of normal saline

Interventions

GTX-B001

Single infusion of one of up to five dosages of GTX-B001

Intervention Type: DRUG

Normal Saline

Single infusion of normal saline

Intervention Type: DRUG

Other Intervention Names

ALY-301

Eligibility Criteria

Inclusion Criteria

• 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.

• 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.

Exclusion Criteria

• 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).

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Granular Therapeutics Limited

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Charité Research Organization gmbh

Berlin, , Germany

Site Status: RECRUITING

Fraunhofer Institute For Translational Medicine And Pharmacology

Berlin, , Germany

Site Status: NOT_YET_RECRUITING

Countries

Germany

Facility Contacts

Principal Investigator

Role: primary

info@charite-research.org

+49 30 450 539 200

Principal Investigator

Role: primary

study-coordination-berlin@itmp.fraunhofer.de

+49 30 450 518 219

Other Identifiers

2025-522126-13-00

Identifier Type: CTIS

Identifier Source: secondary_id

GRN-GTXB001-001

Identifier Type: -

Identifier Source: org_study_id