An Early Phase 1 interventional study of Nucala in Chronic Spontaneous Urticaria, sponsored by Mayo Clinic. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-27.
Sponsored by Mayo Clinic · Early Phase 1, Interventional, and Treatment
Among 64 studies in Chronic Urticaria with a site in United States — 9 open to participants now, 17 under way, 6 of them phase 3. Chronic Urticaria · United States.
Among the 64 studies in Chronic Urticaria with a site in United States, this one is the 53rd largest by enrollment of the 58 interventional ones that give a count, is one of 6 that started in 2019, is one of 5 in phase 1, and was the 18th registered.
194 studies on the registry are indexed under Chronic Urticaria; 46 are open to participants now.
Browse Chronic Urticaria studies →9 of the 64 studies in Chronic Urticaria with a site in United States are open now. Recruiting first, the newest first:
Calixis Inc. · Sites in United States
Ages 18–85
Enanta Pharmaceuticals, Inc · Sites in United States
Ages 18–65 · Healthy volunteers
Novartis Pharmaceuticals · Sites in United States
Ages 18+
Novartis Pharmaceuticals · Sites in United States
Ages 18–100
Novartis Pharmaceuticals · Sites in United States
Ages 18–100
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 24 Chronic Urticaria studies recruiting now, 11 (46%) set no upper age limit and 9 (38%) stop at 75 or younger; 1 takes children under 18; 5 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
64 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 6 · Phase 2 25 · Phase 3 22 · Phase 4 4
First in 2008; this study’s year is marked. 6 started in 2019.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 10 is below the median of 80 across 145 interventional studies indexed under Chronic Urticaria.
Median enrollment 132 across the 58 interventional studies, 428 across the 6 observational. Of the 44 that completed or were terminated, 30 (68%) have results posted.
This tab as a report to print or save as PDF → With an account.
52 of 64 have an industry lead sponsor. The 10 most frequent:
Mayo Clinic is the lead sponsor of 3,269 studies on the registry; 672 are open to participants now.
Of its 452 completed or terminated interventional studies of FDA-regulated products, 321 (71%) have results posted.
Mayo Clinic has 1 study filed under Chronic Urticaria — fewer than ten, so there is no comparison to draw.
6 of the studies in Chronic Urticaria with a site in United States that are under way reach primary completion within a year, 1 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06868212Phase 3Novartis PharmaceuticalsA Study to Evaluate Efficacy of Remibrutinib Compared to Dupilumab at Early Timepoints in Adults With Chronic Spontaneous Urticaria Inadequately Controlled by Second Generation H1-antihistamines | 2027-02-22 |
| NCT07540910Enanta Pharmaceuticals, IncA Study to Investigate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single and Multiple Doses of EDP-978 in Healthy Adults | 2026-11 |
| NCT07219615PfizerA Study to Learn About Ritlecitinib for the Potential Treatment of Chronic Spontaneous Urticaria in Adults. | 2026-12-25 |
| NCT06931405Blueprint Medicines CorporationStudy of BLU-808 in Chronic Inducible Urticaria (CIndU) and Chronic Spontaneous Urticaria (CSU) | 2026-12-31 |
| NCT06927999ARS Pharmaceuticals, Inc.An Outpatient Study of the Efficacy of ARS-2 in Patients With Chronic Spontaneous Urticaria | 2027-06 |
Among the 64 studies in Chronic Urticaria with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This is an exploratory study designed to generate preliminary data in evaluating the efficacy of Nucala in the treatment of chronic spontaneous urticaria.
This is an open-label, single arm exploratory study of mepolizumab in the treatment of CSU. The primary endpoint will be the mean reduction in the seven day urticaria activity score (UAS7) before and after 10 weeks of treatment with mepolizumab. Secondary endpoints will be the mean reduction of the urticaria control test (UCT) score and the weekly itch severity score (ISS) before and after treatment. Enrollment examination will include a standardized history and examination, baseline UCT score, CBC with differential, serum IgE level, chronic urticaria index, IgE Fc receptor antibody functional assay, and a 4 mm punch biopsy of lesional skin to confirm the urticarial tissue reaction includes eosinophils and is not neutrophilic predominant. Patients will discontinue all anti-histamines and start cetirizine 10 mg PO BID which may be continued throughout the study duration. Patients will be provided with a log book to track daily urticaria signs and symptoms in a standardized manner for UAS scoring. At week 0 (enrollment visit +7 days), baseline UAS7 and ISS score will be assessed and skin biopsy results reviewed. Patients with a confirmatory skin biopsy will receive 200 mg SC of mepolizumab at week 0,2,4,6,and 8. UAS-7 and weekly ISS score will be calculated at week 0, 4, 8, and 10. UCT scoring will be calculated at week 0 and at week 10. Repeat CBC with differential, serum IgE level, and measures of basophil serum activation (chronic urticaria index, IgE FC Receptor antibody functional assay) will be assessed at week 10. Attached to this document is a protocol summary.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This is an open-label pilot investigation and all study participants are assigned to active treatment. There is no placebo arm in this study.
Drug: Nucala
All study participants will receive Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Also known as: Mepolizumab
Reduction in Urticaria Activity Score (UAS7)
Study participants documented their chronic spontaneous urticaria (CSU) symptoms using a diary, daily scoring for a) the number of wheals \[none (=0 points), \<10 (=1 point), 10-50 (=2 points), or \>50 per day (=3 points)\], and b) the intensity of pruritus \[none (=0 points), mild (=1 point), moderate (=2 points), severe (=3 points)\]. The daily UAS score is summed over a week to calculate the UAS7 score (range: 0-42). Participants were considered responders if they had ≥ 95% reduction in baseline UAS7 score and non-responders if they had \<95% reduction in baseline UAS7 score.
Time frame: Baseline to 10 Weeks
Change in Short Form Urticaria Control Test Score (S-UCT)
The short form urticaria control test (S-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The S-UCT consists of 4 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum S-UCT scores are 0-16 with 16 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline S-UCT score and non-responders if they had \<95% reduction in baseline S-UCT score.
Time frame: Baseline to 10 weeks
Change in Long Form Urticaria Control Test (L-UCT) Score
The long form urticaria control test (L-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The L-UCT consists of 8 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum L-UCT scores are 0-32 with 32 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline L-UCT score and non-responders if they had \<95% reduction in baseline L-UCT score.
Time frame: Baseline to 10 Weeks
Change in Itch Severity Score (ISS)
The weekly itch severity score measures the intensity and impact of itching (pruritus). It is calculated using the pruritus score of the daily Urticaria Activity Score (UAS) score summed over a week. Scores range from 0 to 21 with higher scores indicating worse itching. Participants were considered responders if they had ≥ 95% reduction in baseline ISS score and non-responders if they had \<95% reduction in baseline ISS score.
Time frame: Baseline to 10 weeks
| Milestone | Treatment Arm |
|---|---|
| Started | 10 |
| Completed | 10 |
| Not completed | 0 |
Study participants documented their chronic spontaneous urticaria (CSU) symptoms using a diary, daily scoring for a) the number of wheals \[none (=0 points), \<10 (=1 point), 10-50 (=2 points), or \>50 per day (=3 points)\], and b) the intensity of pruritus \[none (=0 points), mild (=1 point), moderate (=2 points), severe (=3 points)\]. The daily UAS score is summed over a week to calculate the UAS7 score (range: 0-42). Participants were considered responders if they had ≥ 95% reduction in baseline UAS7 score and non-responders if they had \<95% reduction in baseline UAS7 score.
| Participants | Treatment Arm |
|---|---|
| Responders | 3 |
| Non-Responders | 7 |
The short form urticaria control test (S-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The S-UCT consists of 4 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum S-UCT scores are 0-16 with 16 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline S-UCT score and non-responders if they had \<95% reduction in baseline S-UCT score.
| score on a scale | Treatment Arm |
|---|---|
| Responders | 12.3 (0 to 16) |
| Non-responders | 0.71 (0 to 16) |
The long form urticaria control test (L-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The L-UCT consists of 8 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum L-UCT scores are 0-32 with 32 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline L-UCT score and non-responders if they had \<95% reduction in baseline L-UCT score.
| score on a scale | Treatment Arm |
|---|---|
| Responders | 21.3 (0 to 32) |
| Non-Responders | 1.6 (0 to 32) |
The weekly itch severity score measures the intensity and impact of itching (pruritus). It is calculated using the pruritus score of the daily Urticaria Activity Score (UAS) score summed over a week. Scores range from 0 to 21 with higher scores indicating worse itching. Participants were considered responders if they had ≥ 95% reduction in baseline ISS score and non-responders if they had \<95% reduction in baseline ISS score.
| score on a scale | Treatment Arm |
|---|---|
| Responders | 13 (0 to 21) |
| Non-Responders | 1 (0 to 21) |
Collected over Adverse events were collected from baseline through end of study participation, approximately 10 weeks.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Treatment Arm | 0/10 (0%) | 0/10 (0%) | 1/10 (10%) |
| Event | Treatment Arm |
|---|---|
| Facial SwellingGeneral disorders | 1/10 |
| Age, Categorical(Participants) | Treatment Arm |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 9 |
| >=65 years | 1 |
| Sex: Female, Male(Participants) | Treatment Arm |
|---|---|
| Female | 8 |
| Male | 2 |
| Ethnicity (NIH/OMB)(Participants) | Treatment Arm |
|---|---|
| Hispanic or Latino | 0 |
| Not Hispanic or Latino | 10 |
| Unknown or Not Reported | 0 |
| Race (NIH/OMB)(Participants) | Treatment Arm |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 1 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 0 |
| White | 9 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(participants) | Treatment Arm |
|---|---|
| United States | 10 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Jul 2019 to primary completion in Nov 2023, 51 months.
Results were first posted in Aug 2025, 1 year 9 months after primary completion.
Of 15 phase 1 interventional studies under Chronic Urticaria, half reached primary completion within 15 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 21. This study's 51 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Aug 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Mepolizumab