A Study of KT-621 Administered Orally to Adult Participants with Moderate to Severe Eosinophilic Asthma

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Kymera Therapeutics Inc.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Immune System Diseases [C20]

Trial duration

21 May 2026 → ongoing

Decision date (initial)

2026-04-19

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

Kymera Therapeutics, Inc.

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Pharmacokinetic, Safety, Others, Efficacy

To evaluate the efficacy of multiple doses of KT-621 compared to placebo in participants with uncontrolled moderate to severe eosinophilic asthma

Secondary objectives 2

1. To evaluate the safety and tolerability of multiple doses of KT-621 compared to placebo in participants with uncontrolled moderate to severe eosinophilic asthma
2. To characterize the PK of KT-621 in participants with uncontrolled moderate to severe eosinophilic asthma

Conditions and MedDRA coding

Uncontrolled Moderate to Severe Eosinophilic Asthma

Study design 1 period

Regulatory references

Scientific advice from competent authorities

Federal Institute For Drugs And Medical Devices, Food And Drug Administration, Danish Medicines Agency

Plan to share IPD

No

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 10

1. 9. 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 (V1).
2. 10. Male or female assigned at birth, inclusive of all gender identities. Contraceptive use by participants or participant partners should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
3. 1. 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.
4. 2. Must have a physician diagnosis of asthma for ≥ 52 weeks prior to the Screening visit (V1), based on the Global Initiative for Asthma (GINA) 2024 guidelines.
5. 3. Must be on a stable regimen of medium- to high- 500 µg fluticasone propionate dry powder formulation or an equivalent total daily dose, in combination with a LABA. The regimen may include additional controller medication such as an LTRA and/or LAMA 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 (V1) and between the Screening and Baseline visits (V2).
6. 4. Morning pre-bronchodilator FEV1 40 to 80% of predicted normal at the Screening visit (V1) and the Baseline visit (V2), prior to randomization; up to 2 repeat assessments (3 total) are allowed during the Screening period up to the Baseline visit.
7. 5. ACQ-5 score ≥ 1.5 at the Screening visit (V1) and at the Baseline visit (V2), prior to randomization.
8. 6. A FeNO level of ≥ 25 ppb at the Screening visit (v1) and the Baseline visit (V2); up to 2 repeat assessments (3 total) are allowed during the Screening period up to the Baseline visit.
9. 7. Demonstrated evidence of reversible airway obstruction by post-bronchodilator (albuterol/salbutamol) reversibility of FEV1 at Screening (15-30 min after administration of 2 to 4 puffs of albuterol/salbutamol); up to 2 repeat assessments (3 total) are allowed during the screening period up to the Baseline visit (V2).
10. 8. Absolute blood eosinophil count must be ≥0.30 x 10^9/L at Screening; up to 2 repeat assessments (3 total) are allowed during the screening period up to the Baseline visit (V2).

Exclusion criteria 13

1. 1. The presence of any clinically significant pulmonary disease other than asthma, including, but not limited to, active lung infection, chronic obstructive pulmonary disease (COPD), bronchiectasis, pulmonary fibrosis, cystic fibrosis, obesity associated hypoventilation syndrome, lung cancer, alpha 1 antitrypsin deficiency, or primary ciliary dyskinesia. Additionally, any pulmonary or systemic condition other than asthma that is associated with elevated peripheral eosinophil counts, such as allergic bronchopulmonary aspergillosis/mycosis, Churg Strauss syndrome, or hypereosinophilic syndrome.
2. 2. 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 (V1) up to and including the Baseline visit (V2).
3. 3. Has had any of the following at Screening: a. Positive human immunodeficiency virus (HIV) antibody b. Positive hepatitis B (HBV) surface antigen (HBsAg) c. Positive total hepatitis B core antibody (HBcAb) d. Positive hepatitis C virus (HCV) antibody e. Have evidence of active or latent or inadequately treated infection with mycobacterium tuberculosis (TB)
4. 4. Has any of the following findings at the Screening visit (V1): a. Inadequate hematological function, as follows: i. Platelet count < 100 × 10^9/L (< 100,000/µL) ii. Hemoglobin < 9 g/dL iii. Absolute neutrophil count < 1.5 × 10^9/L (< 1,500/µL) b. Inadequate liver function, as follows: i. Aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) > 2 × upper limit of normal (ULN) ii. Total bilirubin > 1.5 x ULN (participants with Gilbert's syndrome can be included with total bilirubin > 1.5 × ULN) as long as direct bilirubin is ≤ 1.5 x ULN)
5. 5, Known or suspected history of immunodeficiency disorder, including history of invasive opportunistic infections (eg, histoplasmosis, listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis), despite infection resolution; or unusually frequent, recurrent or prolonged infections, per Investigator's judgment.
6. 6. Has a clinically significant history or evidence of any active or suspected parasitic infection within 4 weeks of the Baseline visit (V2) or has travelled within the 3 months before Baseline to areas of high parasitic exposure, as determined by local or international health guidelines or epidemiological data.
7. 7. Has had any major surgery within 8 weeks prior to the Screening visit (V1) or has any planned surgical or medical procedure planned during the study
8. 8. Has a chronic or acute infection, including upper or lower respiratory tract infection, requiring treatment with systemic antibiotics, antiparasitics, antifungals, or antivirals that were completed within 4 weeks of Baseline or during the Screening period.
9. 9. Has 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. Examples include, but are not limited to, participants with short life expectancy, participants with uncontrolled diabetes (hemoglobin A1c ≥9%), partecipants with cardiovascular conditions (eg, heart failure, uncontrolled hypertension), severe renal conditions (eg, participants on dialysis), hepatobiliary conditions (eg, Child Pugh class B or C), neurological conditions (eg, demyelinating diseases), active major autoimmune diseases (such as, but not limited to, lupus, inflammatory bowel disease, rheumatoid arthritis), and other severe endocrinological, gastrointestinal, metabolic, pulmonary, or lymphatic diseases.
10. 10. Has any medical or psychiatric condition which, in the opinion of the Investigator or the Sponsor's Medical Monitor, would place the participant at risk, interfere with participation in the study, or interfere with the interpretation of study results.
11. 11. Has a history of alcohol or drug abuse within 2 years of the Screening visit (V1).
12. 12. Current smokers of nicotine/tobacco as well as non-nicotine products, participants with smoking history of ≥10 pack years, and participants using 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 (V1).
13. 13. Has any cancer or a history of cancers within the last 5 years (except curatively treated with surgical excised squamous cell carcinoma, basal cell carcinoma, or carcinoma in situ of the skin or cervix).

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Change from baseline to Week 12 in pre-bronchodilator FEV1.

Secondary endpoints 6

1. Change from baseline to Week 12 in post-bronchodilator FEV1.
2. Change from baseline to Week 12 in ACQ-5 score
3. Change from baseline to Week 12 in the AQLQ(S) Global Score
4. Incidence of TEAEs
5. Incidence of treatment-emergent SAEs
6. Plasma PK parameter estimates of KT-621 derived from plasma concentration time data

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 3

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Kymera Therapeutics Inc.

Sponsor organisation

Kymera Therapeutics Inc.

Address

500 North Beacon Street Floor 4

City

Watertown

Postcode

02472-5801

Country

United States

Scientific contact point

Organisation

Kymera Therapeutics Inc.

Contact name

Samyuktha Manne

Public contact point

Organisation

Kymera Therapeutics Inc.

Contact name

Samyuktha Manne

Third parties 9

Locations

8 EU/EEA countries · 45 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 175 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications