A Phase 2 interventional study of ARS-1 in Urticaria, sponsored by ARS Pharmaceuticals, Inc.. Completed at 2 sites in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-04-07.
Sponsored by ARS Pharmaceuticals, Inc. · Phase 2, Interventional, and Treatment
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Among 47 studies in Urticaria with a site in United States — 4 open to participants now, 4 under way, none of them phase 3. Urticaria · United States.
Among the 47 studies in Urticaria with a site in United States, this one is the 26th largest by enrollment of the 37 interventional ones that give a count, is one of 3 that started in 2022, is one of 16 in phase 2, and was the 38th registered.
147 studies on the registry are indexed under Urticaria; 19 are open to participants now.
Browse Urticaria studies →4 of the 47 studies in Urticaria with a site in United States are open now. Recruiting first, the newest first:
Calixis Inc. · Sites in United States
Ages 18–85
Pfizer · Sites in United States, Bulgaria, Canada and 7 more countries
Ages 18+
Foundation For Rare Disease Research · Sites in United States
Ages 12–75 · Healthy volunteers
Columbia University · Sites in United States
Ages up to 99 · Healthy volunteers
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 12 Urticaria studies recruiting now, 3 (25%) set no upper age limit and 6 (50%) stop at 75 or younger; 6 take children under 18; 6 take healthy volunteers.
This study: 18 Years to 65 Years · 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.
47 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 8 · Phase 2 21 · Phase 3 6 · Phase 4 3
First in 1976; this study’s year is marked. 3 started in 2022.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 21 is below the median of 51 across 104 interventional studies indexed under Urticaria.
Median enrollment 39 across the 37 interventional studies, 83 across the 10 observational. Of the 39 that completed or were terminated, 21 (54%) have results posted.
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22 of 47 have an industry lead sponsor. The 10 most frequent:
ARS Pharmaceuticals, Inc. is the lead sponsor of 5 studies on the registry; 2 are open to participants now.
ARS Pharmaceuticals, Inc. has 1 study filed under Urticaria — fewer than ten, so there is no comparison to draw.
3 of the studies in Urticaria with a site in United States that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07219615PfizerA Study to Learn About Ritlecitinib for the Potential Treatment of Chronic Spontaneous Urticaria in Adults. | 2026-12-25 |
| NCT05584488Columbia UniversityAllergy and Immunology Natural History Study | 2027-01 |
| NCT06210698Foundation For Rare Disease ResearchAngioedema Biomarker Research Study | 2027-07-31 |
Add all 3 to your calendar (.ics) → With an account.
Among the 47 studies in Urticaria with a site in United States, from their registry updates:
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Determine the effect of ARS-1 on a patient reported pruritus/hive score
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.
7. If male (with or without vasectomy), agree to the use of highly effective methods at screening until 7 days after the last day of study drug.
8. Is able to communicate clearly with the Investigator and staff. 9. Provide written prior to participating in the study.
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
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.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
1 mg ARS-1 IN: placebo: 2 mg ARS-1 IN
Drug: ARS-1
2 mg ARS-1 IN: placebo: 1 mg ARS-1
Drug: ARS-1
A single treatment of ARS-1 1mg, 2 mg or placebo
Effect of ARS-1 Versus Placebo Based on a Patient Reported Pruritus/Hive Score
Assess time to effect and duration of effect on acute flares associated with urticaria based on a patient reported pruritus/hive score, from 0 (none) to 3 (severe) for itch and hive using Uniform Assessment System (UAS) as below: Severity Score Amount of Itch Itch Severity 0 None None 1. Mild Easily tolerated 2. Moderate Bothersome but tolerable 3. Intense Difficult to tolerate Hive Severity Score Number of Hives 0 None 1. 1-6 2. 7-12 3. \>12
Time frame: UAS score at 120 (± 10 min) minutes after dosing.
| Milestone | Sequence 1 | Sequence 2 |
|---|---|---|
| Started | 10 | 11 |
| Completed | 8 | 10 |
| Not completed | 2 | 1 |
Assess time to effect and duration of effect on acute flares associated with urticaria based on a patient reported pruritus/hive score, from 0 (none) to 3 (severe) for itch and hive using Uniform Assessment System (UAS) as below: Severity Score Amount of Itch Itch Severity 0 None None 1. Mild Easily tolerated 2. Moderate Bothersome but tolerable 3. Intense Difficult to tolerate Hive Severity Score Number of Hives 0 None 1. 1-6 2. 7-12 3. \>12
| UAS score 0 to 3 | 1 mg | 2 mg | Placebo |
|---|---|---|---|
| Hives | 1.1 ± 0.3 | 0.8 ± 0.3 | 1.8 ± 0.3 |
| Itch | 0.4 ± 0.1 | 0.3 ± 0.1 | 1.5 ± 0.2 |
Collected over AEs were collected for two hours after dosing.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| ARS-1 1mg | 0/21 (0%) | 0/21 (0%) | 6/21 (28.6%) |
| ARS-1 2mg | 0/21 (0%) | 0/21 (0%) | 7/21 (33.3%) |
| Placebo | 0/21 (0%) | 0/21 (0%) | 0/21 (0%) |
| Event | ARS-1 1mg | ARS-1 2mg | Placebo |
|---|---|---|---|
| Nasal discomfortGeneral disorders | 6/21 | 7/21 | 0/21 |
| Age, Categorical(Participants) | Interventional Treatment |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 21 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | Interventional Treatment |
|---|---|
| Female | 17 |
| Male | 4 |
| Ethnicity (NIH/OMB)(Participants) | Interventional Treatment |
|---|---|
| Hispanic or Latino | 0 |
| Not Hispanic or Latino | 0 |
| Unknown or Not Reported | 21 |
| Race (NIH/OMB)(Participants) | Interventional Treatment |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 0 |
| White | 0 |
| More than one race | 0 |
| Unknown or Not Reported | 21 |
| Region of Enrollment(participants) | Interventional Treatment |
|---|---|
| United States | 21 |
PDFs hosted by the registry, ClinicalTrials.gov.
Ran from Jul 2022 to primary completion in Feb 2024, 19 months.
Results were first posted in Apr 2026, 2 years 1 month after primary completion.
Of 13 phase 2 interventional studies under Urticaria, half reached primary completion within 28 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 32. This study's 19 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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ARS Pharmaceuticals, Inc.