Healthy SubjectsPhase 1CHILL-MCNCT07181369
A Phase 1 Study of GTX-B001 in Healthy Subjects and Patients With Chronic Inducible Urticaria
A Phase 1 study testing GTX-B001 and Normal Saline in people with Healthy Subjects and Cold Urticaria, run by Granular Therapeutics Limited at 3 sites in Germany.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Subjects, Cold Urticaria, Symptomatic Dermographism
- What is being tested?
- GTX-B001 and Normal Saline
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 72 participants
- Where
- 3 sitesGermany
- Study dates
- 6 Oct 2025to Aug 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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:
Show all 9Show fewer
- 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).
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Germany3 sites, 2 recruiting
- Active, not recruiting
Charité Research Organization gmbh
Berlin
- Recruiting
Fraunhofer Institute For Translational Medicine And Pharmacology
Berlin
Principal Investigator, +49 30 450 518 219, hautsache-ifa@charite.de
- Recruiting
Dermatologische Praxis
Halle
Principal Investigator, +493452082056, info@hautarzthalle.de
About this study
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)
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.
Read the 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.
- Being tested
- GTX-B001, Normal Saline
- Keywords
- Urticaria, Skin diseases, Mast cells, Bispecific antibody, GTX-B001, Infusion, Single Ascending Dose, Healthy subjects, Safety, Pharmacokinetics, Pharmacodynamics, Cold urticaria, Intravenous, symptomatic dermographism
- Medical subject headings
- Cold Urticaria, Familial dermographism, Chronic Inducible Urticaria, Urticaria, Skin Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GTX-B001Drug
Also called ALY-301
Single infusion of one of up to five dosages of GTX-B001
Normal SalineDrug
Single infusion of normal saline
| Study group | Role | What they receive |
|---|---|---|
| Part A (HV) - GTX-B001 | Experimental | Healthy participants will receive a single dose of GTX-B001 Receives: Drug: GTX-B001 |
| Part A (HV) - Normal Saline | Placebo comparator | Healthy participants assigned to receive placebo will receive a single dose of normal saline Receives: Drug: Normal Saline |
| Part B (ColdU/SD) - GTX-B001 | Experimental | Patients with cold urticaria or symptomatic dermographism will receive a single dose of GTX-B001 Receives: Drug: GTX-B001 |
| Part B (ColdU/SD) - Normal Saline | Placebo comparator | Patients with cold urticaria or symptomatic dermographism assigned to receive placebo will receive a single dose of normal saline Receives: Drug: Normal Saline |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety as assessed by the incidence and severity of adverse events (Parts A and B)
Safety and tolerability of a single intravenous infusion of GTX-B001 as assessed by the percentage of subjects at each dose level with Grade 2 or higher adverse events as assessed by the Common Terminology Criteria for Adverse Events (CTCAE).
Measured: Day 1 to Day 85
Secondary outcomes (1)
GTX-B001 pharmacokinetics (Parts A and B)
Serum concentrations of GTX-B001 at specified visits
Measured: Day 1 to Day 85
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Sep 2025
- Study start6 Oct 2025
- Primary completionAug 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy SubjectsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Single Ascending Dose
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 72 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Granular Therapeutics Limited
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07181369
- Sponsor's protocol ID
- GRN-GTXB001-001
- Other IDs
- 2025-522126-13-00, 2025
- Acronym
- CHILL-MC
- Status last verified
- Sep 2026
- First submitted
- 12 Sep 2025
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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)
- ClinicalTrials.gov ID
- NCT07181369
- Acronym / sponsor ID
- CHILL-MC / GRN-GTXB001-001
- Keywords
- Urticaria, Skin diseases, Mast cells, Bispecific antibody, GTX-B001, Infusion, Single Ascending Dose, Healthy subjects
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 72 participants (estimated)
- Lead sponsor
- Granular Therapeutics LimitedIndustry (pharma, biotech, devices)
- Study start
- 6 Oct 2025 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 18 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
- Model description
- Single Ascending Dose
| Arm | Type | Receives |
|---|---|---|
| Part A (HV) - GTX-B001 | Experimental | Drug: GTX-B001Healthy participants will receive a single dose of GTX-B001 |
| Part A (HV) - Normal Saline | Placebo comparator | Drug: Normal SalineHealthy participants assigned to receive placebo will receive a single dose of normal saline |
| Part B (ColdU/SD) - GTX-B001 | Experimental | Drug: GTX-B001Patients with cold urticaria or symptomatic dermographism will receive a single dose of GTX-B001 |
| Part B (ColdU/SD) - Normal Saline | Placebo comparator | Drug: Normal SalinePatients with cold urticaria or symptomatic dermographism assigned to receive placebo will receive a single dose of normal saline |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- 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.
Key exclusion criteria (9 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GTX-B001Also: ALY-301Single infusion of one of up to five dosages of GTX-B001 | Drug | Part A (HV) - GTX-B001, Part B (ColdU/SD) - GTX-B001 |
| Normal SalineSingle infusion of normal saline | Drug | Part A (HV) - Normal Saline, Part B (ColdU/SD) - Normal Saline |
Primary outcome
Safety as assessed by the incidence and severity of adverse events (Parts A and B)
Time frame: Day 1 to Day 85
Safety and tolerability of a single intravenous infusion of GTX-B001 as assessed by the percentage of subjects at each dose level with Grade 2 or higher adverse events as assessed by the Common Terminology Criteria for Adverse Events (CTCAE).
1 secondary outcome
GTX-B001 pharmacokinetics (Parts A and B)
Time frame: Day 1 to Day 85
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Fraunhofer Institute For Translational Medicine And Pharmacology
Berlin, Germany
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing GTX-B001 and Normal Saline in people with Healthy Subjects and Cold Urticaria, run by Granular Therapeutics Limited at 3 sites in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety as assessed by the incidence and severity of adverse events (Parts A and B) (time frame: Day 1 to Day 85). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2026.