Eosinophilic AsthmaPhase 2BREADTHNCT07323654
A Study of KT-621 Administered Orally to Adult Participants With Moderate to Severe Eosinophilic Asthma
A Phase 2 study testing KT-621 in people with Eosinophilic Asthma, run by Kymera Therapeutics, Inc. at 81 sites in 13 countries.
Trial summary
This Phase 2b study is designed to evaluate the safety and efficacy of KT-621 in participants with uncontrolled moderate to severe eosinophilic asthma. The main goals of this study are to investigate how effective KT-621 is at treating uncontrolled moderate to severe eosinophilic asthma, the safety and tolerability of… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Eosinophilic Asthma
- What is being tested?
- KT-621
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 264 participants
- Where
- 81 sitesin 13 countries
- Study dates
- 28 Jan 2026to Dec 2027
- Phase
- Phase 2
- 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
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Must be 18 years old (or the legal age of consent in the jurisdiction in which the study is taking place) to 75 years of age, inclusive, at the time of signing the ICF.
- Must have a physician diagnosis of asthma for at least 1 year prior to the Screening visit.
- Must be on a stable regimen of medium- to high- dose inhaled corticosteroid (ICS), in combination with a long-acting β2-agonist (LABA). The regimen may include additional controller medications used for at least 12 weeks, at a stable dose and regimen, with no change in the dose or frequency of administration for at least 4 weeks prior to the Screening visit and between the Screening and Baseline visits.
- Must have a pre-bronchodilator FEV1 40 to 80% of predicted normal at the Screening and Baseline visits, prior to randomization.
- Must have an ACQ-5 score ≥ 1.5 at the Screening and Baseline visits, prior to randomization.
- Must have a FeNO level of ≥ 25 ppb at the Screening and Baseline visits.
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- Must have a demonstrated evidence of reversible airway obstruction by post-bronchodilator (albuterol/salbutamol) reversibility of FEV1 ≥12% and ≥200 mL at Screening.
- Must have an absolute blood eosinophil count must be ≥ 0.30 × 10^9/L at Screening.
- Must have a documented history of at least 1 asthma exacerbation requiring either treatment with systemic corticosteroids (intramuscular, intravenous, or oral) and/or hospitalization or an emergency/urgent medical care visit for acute asthma worsening within the past 52 weeks prior to Screening.
- Must agree to contraceptive requirements in compliance with the clinical study and local requirements.
- Must be willing and able to comply with scheduled visits, treatment plan, laboratory tests, other study-related procedures, and questionnaires, including completing the electronic diary (e-diary), for the duration of the study as required by the study protocol.
Who cannot join
- Must not have any clinically significant pulmonary disease other than asthma.
- Must not have had an asthma exacerbation, requiring either treatment with systemic corticosteroids (intramuscular, intravenous, or oral) and/or hospitalization or an emergency/urgent medical care visit for acute asthma worsening, at any time from 4 weeks prior to the Screening visit up to and including the Baseline visit.
- Must not have any other clinically significant disease, condition, or medical history that, in the opinion of the Investigator, would interfere with participant safety, study evaluations, and/or study procedures.
- Must not be pregnant or breastfeeding; must not be a woman planning to become pregnant or breastfeed during the study.
- Must not have results from clinical laboratory safety tests that are outside the local reference range at Screening.
- Must not have been dosed with any investigational drug or device in a clinical study within 8 weeks or 5 half-lives (whichever is longer) of KT-621 administration.
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- Must not have any known factor, condition, or disease that might interfere with treatment compliance, study conduct or interpretation of the results.
- Must not be a current smoker of nicotine/tobacco as well as non-nicotine products, have a smoking history of ≥ 10 pack years, or use vaping products, including electronic cigarettes. Former smokers with a smoking history of < 10 pack years and users of vaping or e-cigarette products must have stopped for at least 26 weeks prior to the Screening visit.
- Must not have a known sensitivity to any of the components of KT-621.
- Must not be a member of the investigational team or his/her immediate family.
Trial locations and contacts
81 sites in 13 countries. Contact the study team or a site near you to ask about taking part.
81 sites in 13 countries
United States34 sites, 34 recruiting
- Recruiting
Kymera Investigative Site
Aurora, Colorado, 80045
- Recruiting
Kymera Investigative Site
Boston, Massachusetts, 02114
- Recruiting
Kymera Investigative Site
Chapel Hill, North Carolina, 27517
- Recruiting
Kymera Investigative Site
Chattanooga, Tennessee, 37403
- Recruiting
Kymera Investigative Site
Clackamas, Oregon, 97015
- Recruiting
Kymera Investigative Site
Dallas, Texas, 75209
- Recruiting
Kymera Investigative Site
Dallas, Texas, 75246
- Recruiting
Kymera Investigative Site
Durham, North Carolina, 27705
- Recruiting
Kymera Investigative Site
East Point, Georgia, 30344
- Recruiting
Kymera Investigative Site
Edmond, Oklahoma, 73034
- Recruiting
Kymera Investigative Site
Iowa City, Iowa, 52242
- Recruiting
Kymera Investigative Site
Kansas City, Kansas, 66160
- Recruiting
Kymera Investigative Site
Lancaster, California, 93534
- Recruiting
Kymera Investigative Site
Long Beach, California, 90815
- Recruiting
Kymera Investigative Site
Louisville, Kentucky, 40217
- Recruiting
Kymera Investigative Site
Loxahatchee Groves, Florida, 33470
- Recruiting
Kymera Investigative Site
Madison, Wisconsin, 53792
- Recruiting
Kymera Investigative Site
McKinney, Texas, 75069
- Recruiting
Kymera Investigative Site
Miami, Florida, 33126
- Recruiting
Kymera Investigative Site
Miami, Florida, 33173
- Recruiting
Kymera Investigative Site
Miami Lakes, Florida, 33014
- Recruiting
Kymera Investigative Site
New Haven, Connecticut, 06519
- Recruiting
Kymera Investigative Site
North Charleston, South Carolina, 29406
- Recruiting
Kymera Investigative Site
Northridge, California, 91324
- Recruiting
Kymera Investigative Site
Orlando, Florida, 32819
- Recruiting
Kymera Investigative Site
Philadelphia, Pennsylvania, 19140
- Recruiting
Kymera Investigative Site
Pittsburgh, Pennsylvania, 15213
- Recruiting
Kymera Investigative Site
Pittsburgh, Pennsylvania, 15241
- Recruiting
Kymera Investigative Site
Redding, California, 96001
- Recruiting
Kymera Investigative Site
Rock Hill, South Carolina, 29732
- Recruiting
Kymera Investigative Site
San Francisco, California, 94112
- Recruiting
Kymera Investigative Site
Tampa, Florida, 33607
- Recruiting
Kymera Investigative Site
Toledo, Ohio, 43617
- Recruiting
Kymera Investigative Site
Upland, California, 91786
Poland9 sites, 9 recruiting
- Recruiting
Kymera Investigative Site
Bialystok
- Recruiting
Kymera Investigative Site
Gdansk
- Recruiting
Kymera Investigative Site
Lodz
- Recruiting
Kymera Investigative Site
Poznan
- Recruiting
Kymera Investigative Site
Sosnowiec
- Recruiting
Kymera Investigative Site
Tarnów
- Recruiting
Kymera Investigative Site
Trzebnica
- Recruiting
Kymera Investigative Site
Wroclaw
- Recruiting
Kymera Investigative Site
Zawadzkie
Argentina7 sites, 7 recruiting
- Recruiting
Kymera Investigative Site
Buenos Aires
- Recruiting
Kymera Investigative Site
Concepción del Uruguay
- Recruiting
Kymera Investigative Site
Lobos
- Recruiting
Kymera Investigative Site
Mar del Plata
- Recruiting
Kymera Investigative Site
Quilmes
- Recruiting
Kymera Investigative Site
Rosario
- Recruiting
Kymera Investigative Site
San Miguel de Tucumán
United Kingdom6 sites, 6 recruiting
- Recruiting
Kymera Investigative Site
Bedford, MK40 2FG
- Recruiting
Kymera Investigative Site
Birmingham
- Recruiting
Kymera Investigative Site
Bristol
- Recruiting
Kymera Investigative Site
Leicester
- Recruiting
Kymera Investigative Site
London
- Recruiting
Kymera Investigative Site
Wythenshawe
Spain5 sites, 5 recruiting
- Recruiting
Kymera Investigative Site
Cadiz
- Recruiting
Kymera Investigative Site
Jerez de la Frontera
- Recruiting
Kymera Investigative Site
Madrid
- Recruiting
Kymera Investigative Site
Mataró
- Recruiting
Kymera Investigative Site
Santander
Belgium4 sites, 4 recruiting
- Recruiting
Kymera Investigative Site
Brussels
- Recruiting
Kymera Investigative Site
Erpent
- Recruiting
Kymera Investigative Site
Ghent
- Recruiting
Kymera Investigative Site
Liège
Serbia4 sites, 4 recruiting
- Recruiting
Kymera Investigative Site
Belgrade, 11000
- Recruiting
Kymera Investigative Site
Belgrade
- Recruiting
Kymera Investigative Site
Kamenitz, 21204
- Recruiting
Kymera Investigative Site
Užice, 31000
Romania3 sites, 3 recruiting
- Recruiting
Kymera Investigative Site
Brasov
- Recruiting
Kymera Investigative Site
Craiova
- Recruiting
Kymera Investigative Site
Timișoara
Slovakia3 sites, 3 recruiting
- Recruiting
Kymera Investigative Site
Bardejov
- Recruiting
Kymera Investigative Site
Košice
- Recruiting
Kymera Investigative Site
Spišská Nová Ves
Germany2 sites, 2 recruiting
- Recruiting
Kymera Investigative Site
Berlin
- Recruiting
Kymera Investigative Site
Leipzig
South Korea2 sites, 2 recruiting
- Recruiting
Kymera Investigative Site
Gyeonggi-do
- Recruiting
Kymera Investigative Site
Seoul
About this study
Official title: A Phase 2b, Randomized, Double-blind, Placebo-controlled, Parallel-group, Multicenter, Dose-ranging Study Investigating the Efficacy and Safety Profile of KT-621 Administered Orally to Adult Participants With Uncontrolled Moderate to Severe Eosinophilic Asthma
This Phase 2b study is designed to evaluate the safety and efficacy of KT-621 in participants with uncontrolled moderate to severe eosinophilic asthma.
The main goals of this study are to investigate how effective KT-621 is at treating uncontrolled moderate to severe eosinophilic asthma, the safety and tolerability of KT-621, and how KT-621 behaves in the body.
- Conditions
- Eosinophilic Asthma
- Being tested
- KT-621, Placebo
- Keywords
- kt-621, stat6 degrader, stat6, targeted protein degrader, Phase 2, phase 2b
- Medical subject headings
- Pulmonary Eosinophilia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KT-621Drug
Oral drug
PlaceboOther
Oral placebo matched to KT-621
| Study group | Role | What they receive |
|---|---|---|
| Group 1: KT-621 Dose 1 | Experimental | Not described Receives: Drug: KT-621 |
| Group 2: KT-621 Dose 2 | Experimental | Not described Receives: Drug: KT-621 |
| Group 3: KT-621 Dose 3 | Experimental | Not described Receives: Drug: KT-621 |
| Group 4: Placebo | Placebo comparator | Not described Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in pre-bronchodilator FEV1
Measured: From baseline to Week 12
Secondary outcomes (6)
Change from baseline in post-bronchodilator FEV1
Measured: From baseline to Week 12
Change from baseline in Asthma Control Questionnaire 5-question version (ACQ-5) score
Measured: From baseline to Week 12
Change from baseline in Standardized Asthma Quality of Life Questionnaire [AQLQ(S)] Global Score
Measured: From baseline to Week 12
Incidence of treatment-emergent adverse events (TEAEs)
Measured: From baseline through Week 16
Incidence of treatment-emergent serious adverse events (SAEs)
Measured: From baseline through Week 16
Plasma concentration of KT-621 derived from plasma concentration time data
Measured: From baseline to Week 16
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jan 2026
- Study start28 Jan 2026
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Eosinophilic AsthmaStudies 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 264 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kymera Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07323654
- Sponsor's protocol ID
- KT621-AS-202
- Acronym
- BREADTH
- Status last verified
- Jan 2026
- First submitted
- 6 Jan 2026
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2b, Randomized, Double-blind, Placebo-controlled, Parallel-group, Multicenter, Dose-ranging Study Investigating the Efficacy and Safety Profile of KT-621 Administered Orally to Adult Participants With Uncontrolled Moderate to Severe Eosinophilic Asthma
- ClinicalTrials.gov ID
- NCT07323654
- Acronym / sponsor ID
- BREADTH / KT621-AS-202
- Conditions
- Eosinophilic Asthma
- Keywords
- kt-621, stat6 degrader, stat6, targeted protein degrader, Phase 2, phase 2b
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 264 participants (estimated)
- Lead sponsor
- Kymera Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 28 Jan 2026 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 7 Jan 2026 (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 Phase 2b study is designed to evaluate the safety and efficacy of KT-621 in participants with uncontrolled moderate to severe eosinophilic asthma.
The main goals of this study are to investigate how effective KT-621 is at treating uncontrolled moderate to severe eosinophilic asthma, the safety and tolerability of KT-621, and how KT-621 behaves in the body.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Group 1: KT-621 Dose 1 | Experimental | Drug: KT-621 |
| Group 2: KT-621 Dose 2 | Experimental | Drug: KT-621 |
| Group 3: KT-621 Dose 3 | Experimental | Drug: KT-621 |
| Group 4: Placebo | Placebo comparator | Other: Placebo |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- Must be 18 years old (or the legal age of consent in the jurisdiction in which the study is taking place) to 75 years of age, inclusive, at the time of signing the ICF.
- Must have a physician diagnosis of asthma for at least 1 year prior to the Screening visit.
- Must be on a stable regimen of medium- to high- dose inhaled corticosteroid (ICS), in combination with a long-acting β2-agonist (LABA). The regimen may include additional controller medications used for at least 12 weeks, at a stable dose and regimen, with no change in the dose or frequency of administration for at least 4 weeks prior to the Screening visit and between the Screening and Baseline visits.
- Must have a pre-bronchodilator FEV1 40 to 80% of predicted normal at the Screening and Baseline visits, prior to randomization.
- Must have an ACQ-5 score ≥ 1.5 at the Screening and Baseline visits, prior to randomization.
Key exclusion criteria (10 listed)
- Must not have any clinically significant pulmonary disease other than asthma.
- Must not have had an asthma exacerbation, requiring either treatment with systemic corticosteroids (intramuscular, intravenous, or oral) and/or hospitalization or an emergency/urgent medical care visit for acute asthma worsening, at any time from 4 weeks prior to the Screening visit up to and including the Baseline visit.
- Must not have any other clinically significant disease, condition, or medical history that, in the opinion of the Investigator, would interfere with participant safety, study evaluations, and/or study procedures.
- Must not be pregnant or breastfeeding; must not be a woman planning to become pregnant or breastfeed during the study.
- Must not have results from clinical laboratory safety tests that are outside the local reference range at Screening.
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 |
|---|---|---|
| KT-621Oral drug | Drug | Group 1: KT-621 Dose 1, Group 2: KT-621 Dose 2, Group 3: KT-621 Dose 3 |
| PlaceboOral placebo matched to KT-621 | Other | Group 4: Placebo |
Primary outcome
Change from baseline in pre-bronchodilator FEV1
Time frame: From baseline to Week 12
6 secondary outcomes
Change from baseline in post-bronchodilator FEV1
Time frame: From baseline to Week 12
Change from baseline in Asthma Control Questionnaire 5-question version (ACQ-5) score
Time frame: From baseline to Week 12
Change from baseline in Standardized Asthma Quality of Life Questionnaire [AQLQ(S)] Global Score
Time frame: From baseline to Week 12
Incidence of treatment-emergent adverse events (TEAEs)
Time frame: From baseline through Week 16
Incidence of treatment-emergent serious adverse events (SAEs)
Time frame: From baseline through Week 16
Plasma concentration of KT-621 derived from plasma concentration time data
Time frame: From baseline to Week 16
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 6 Oct 2026.
- BREADTH Trial WebsiteLink provided by the sponsor.
- 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.
81 sites in 13 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing KT-621 in people with Eosinophilic Asthma, run by Kymera Therapeutics, Inc. at 81 sites in 13 countries.
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 11 inclusion and 10 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 6 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 81 sites in United States, Poland, Argentina, United Kingdom, Spain and 8 more countries. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Contact Kymera Medical Director (857-285-5300, clinicaltrials@kymeratx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline in pre-bronchodilator FEV1 (time frame: From baseline to Week 12). 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 6 Oct 2026.