Asthma (Diagnosis)Phase 2BREADTH-EXTNCT07677059
A Long-term Study of KT-621 Administered Orally to Participants With Asthma Previously Enrolled in a KT-621 Asthma Study
A Phase 2 study testing KT-621 in people with Asthma (Diagnosis), run by Kymera Therapeutics, Inc. at 7 sites in 4 countries.
Trial summary
This Phase 2b open-label, long-term extension study is designed to evaluate the long-term safety and efficacy of KT-621 in participants with asthma who were previously enrolled in the parent study (KT621-AS-202) of KT-621 for asthma. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Asthma (Diagnosis)
- What is being tested?
- KT-621
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 264 participants
- Where
- 7 sitesin 4 countries
- Study dates
- 25 Jun 2026to Dec 2028
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Must have completed all visits of the parent study, per its protocol, up to the end of treatment (EoT) visit.
- 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.
- Must agree to contraceptive requirements in compliance with the clinical study and local requirements.
Who cannot join
- Must not have experienced any clinically significant change in health status during the parent study, which, in the opinion of the Investigator, would interfere with participant safety, study evaluations, or compliance with study procedures; or otherwise make the participant unsuitable for participation in this study.
- Must not have developed an AE during the parent study, that in the opinion of the Investigator or of the Sponsor's Medical Monitor, could indicate that continued treatment may present an unreasonable risk for the participant.
- Must not have met permanent discontinuation criteria and/or permanently discontinued study treatment for any reason during the parent study.
- Must not be a member of the Sponsor or site's investigational team or their immediate family.
- Must not be unsuitable to enter the study for any other reason, as judged by the Investigator, including potential risk of noncompliance to study procedures.
Trial locations and contacts
7 sites in 4 countries. Contact the study team or a site near you to ask about taking part.
7 sites in 4 countries
United States3 sites, 3 recruiting
- Recruiting
Kymera Investigative Site
Dallas, Texas, 75209
- Recruiting
Kymera Investigative Site
Miami, Florida, 33173
- Recruiting
Kymera Investigative Site
Tampa, Florida, 33607
Serbia2 sites, 2 recruiting
- Recruiting
Kymera Investigative Site
Kamenitz
- Recruiting
Kymera Investigative Site
Užice
About this study
Official title: A Multicenter, Open-Label, Long-Term Extension Study to Evaluate the Long-Term Safety and Tolerability of KT-621 in Participants With Asthma Previously Enrolled in a KT-621 Asthma Study
This Phase 2b open-label, long-term extension study is designed to evaluate the long-term safety and efficacy of KT-621 in participants with asthma who were previously enrolled in the parent study (KT621-AS-202) of KT-621 for asthma. The main goals of this study are to investigate the long-term safety and tolerability of KT-621, the long-term efficacy of KT-621 at treating asthma, and how KT-621 behaves in the body long-term.
- Conditions
- Asthma (Diagnosis)
- Being tested
- KT-621
- Keywords
- KT-621, STAT6, stat6 degrader, targeted protein degrader, Phase 2, phase 2b, OLE, LTE
- Medical subject headings
- Asthma, Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KT-621Drug
Oral drug
| Study group | Role | What they receive |
|---|---|---|
| KT-621 | Experimental | Not described Receives: Drug: KT-621 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of treatment-emergent adverse events (TEAEs)
Measured: From baseline through Week 52
Incidence of treatment-emergent serious adverse events (SAEs)
Measured: From baseline through Week 52
Secondary outcomes (5)
Change from baseline in pre-bronchodilator FEV1
Measured: From baseline (as assessed in the parent study) to Week 52
Change from baseline in post-bronchodilator FEV1
Measured: From baseline (as assessed in the parent study) to Week 52
Change from baseline in Asthma Control Questionnaire 5-question version (ACQ-5) score
Measured: From baseline (as assessed in the parent study) to Week 52
Change from baseline in Standardized Asthma Quality of Life Questionnaire [AQLQ(S)] global Score
Measured: From baseline (as assessed in the parent study) to Week 52
Plasma concentration of KT-621 derived from plasma concentration time data
Measured: From baseline to Week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jun 2026
- Study start25 Jun 2026
- Primary completionDec 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Asthma (Diagnosis)Studies 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- 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
- NCT07677059
- Sponsor's protocol ID
- KT621-AS-203
- Acronym
- BREADTH-EXT
- Status last verified
- Jun 2026
- First submitted
- 24 Jun 2026
- Last updated
- 7 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Open-Label, Long-Term Extension Study to Evaluate the Long-Term Safety and Tolerability of KT-621 in Participants With Asthma Previously Enrolled in a KT-621 Asthma Study
- ClinicalTrials.gov ID
- NCT07677059
- Acronym / sponsor ID
- BREADTH-EXT / KT621-AS-203
- Conditions
- Asthma (Diagnosis)
- Keywords
- KT-621, STAT6, stat6 degrader, targeted protein degrader, Phase 2, phase 2b, OLE, LTE
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 264 participants (estimated)
- Lead sponsor
- Kymera Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 25 Jun 2026 (actual)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 30 Jun 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 open-label, long-term extension study is designed to evaluate the long-term safety and efficacy of KT-621 in participants with asthma who were previously enrolled in the parent study (KT621-AS-202) of KT-621 for asthma. The main goals of this study are to investigate the long-term safety and tolerability of KT-621, the long-term efficacy of KT-621 at treating asthma, and how KT-621 behaves in the body long-term.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| KT-621 | Experimental | Drug: KT-621 |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Must have completed all visits of the parent study, per its protocol, up to the end of treatment (EoT) visit.
- 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.
- Must agree to contraceptive requirements in compliance with the clinical study and local requirements.
Key exclusion criteria (5 listed)
- Must not have experienced any clinically significant change in health status during the parent study, which, in the opinion of the Investigator, would interfere with participant safety, study evaluations, or compliance with study procedures; or otherwise make the participant unsuitable for participation in this study.
- Must not have developed an AE during the parent study, that in the opinion of the Investigator or of the Sponsor's Medical Monitor, could indicate that continued treatment may present an unreasonable risk for the participant.
- Must not have met permanent discontinuation criteria and/or permanently discontinued study treatment for any reason during the parent study.
- Must not be a member of the Sponsor or site's investigational team or their immediate family.
- Must not be unsuitable to enter the study for any other reason, as judged by the Investigator, including potential risk of noncompliance to study procedures.
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 | KT-621 |
Primary outcome
Incidence of treatment-emergent adverse events (TEAEs)
Time frame: From baseline through Week 52
Incidence of treatment-emergent serious adverse events (SAEs)
Time frame: From baseline through Week 52
5 secondary outcomes
Change from baseline in pre-bronchodilator FEV1
Time frame: From baseline (as assessed in the parent study) to Week 52
Change from baseline in post-bronchodilator FEV1
Time frame: From baseline (as assessed in the parent study) to Week 52
Change from baseline in Asthma Control Questionnaire 5-question version (ACQ-5) score
Time frame: From baseline (as assessed in the parent study) to Week 52
Change from baseline in Standardized Asthma Quality of Life Questionnaire [AQLQ(S)] global Score
Time frame: From baseline (as assessed in the parent study) to Week 52
Plasma concentration of KT-621 derived from plasma concentration time data
Time frame: From baseline to Week 52
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 7 Oct 2026.
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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.
7 sites in 4 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 Asthma (Diagnosis), run by Kymera Therapeutics, Inc. at 7 sites in 4 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 3 inclusion and 5 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 7 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 7 sites in United States, Serbia, Germany, Poland. 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. 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?
Incidence of treatment-emergent adverse events (TEAEs) (time frame: From baseline through Week 52). The study lists 2 primary outcomes in all. 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 7 Oct 2026.