Phase 2a Study to Assess the Efficacy and Safety of AZD4604 in Adult Patients With Moderate-to-Severe Asthma Uncontrolled on Medium-High Dose ICS-LABA (AJAX)

November 12, 2025 updated by: AstraZeneca

A Phase 2a Randomised, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of AZD4604 Twice Daily for Twelve Weeks in Adult Patients With Moderate-to-Severe Asthma Uncontrolled on Medium-High Dose ICS-LABA

This is a Phase 2a, multicentre, randomised, placebo-controlled, double-blind, parallel-group study to evaluate the efficacy, safety and PK of AZD4604 administered BID using a dry-powder inhaler at one dose level over a 12-week Treatment period in adult participants with uncontrolled moderate-to-severe asthma.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

339

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Argentina
      • Buenos Aires, Argentina, C1425BEN
        • Research Site
      • Buenos Aires, Argentina, C1012AAR
        • Research Site
      • Ciudad de Buenos Aires, Argentina, 1425
        • Research Site
      • Ciudad de Buenos Aires, Argentina, C1414AIF
        • Research Site
      • Florida, Argentina, B1602DQD
        • Research Site
      • La Plata, Argentina, B1900AVG
        • Research Site
      • Ranelagh, Argentina, 1886
        • Research Site
  • Brazil
      • Barretos, Brazil, 14784-400
        • Research Site
      • Blumenau, Brazil, 89030-101
        • Research Site
      • Campinas, Brazil, 13060-080
        • Research Site
      • Campinas, Brazil, 13060-904
        • Research Site
      • Porto Alegre, Brazil, 90160-093
        • Research Site
      • Porto Alegre, Brazil, 90035074
        • Research Site
      • São Bernardo do Campo, Brazil, 09715090
        • Research Site
      • São Bernardo do Campo, Brazil, 09750-420
        • Research Site
      • São José do Rio Preto, Brazil, 15090-000
        • Research Site
  • Bulgaria
      • Pazardzhik, Bulgaria, 4400
        • Research Site
  • Denmark
      • Aalborg, Denmark, 9000
        • Research Site
      • Aarhus, Denmark, 8200
        • Research Site
      • Hvidovre, Denmark, 2650
        • Research Site
      • København NV, Denmark, 2400
        • Research Site
      • København Ø, Denmark, 2100
        • Research Site
      • Vejle, Denmark, 7100
        • Research Site
  • France
      • Lyon, France, 69317
        • Research Site
      • Strasbourg, France, 67091
        • Research Site
  • Germany
      • Berlin, Germany, 10367
        • Research Site
      • Berlin, Germany, 12203
        • Research Site
      • Berlin, Germany, 13187
        • Research Site
      • Berlin, Germany, 12159
        • Research Site
      • Cottbus, Germany, 03050
        • Research Site
      • Frankfurt am Main, Germany, 60596
        • Research Site
      • Koblenz, Germany, 56068
        • Research Site
      • Mainz, Germany, 55128
        • Research Site
      • Peine, Germany, 31224
        • Research Site
  • India
      • Ajmer, India, 305001
        • Research Site
      • Belagavi, India, 590010
        • Research Site
      • Coimbatore, India, 641028
        • Research Site
      • Hyderabad, India, 500068
        • Research Site
      • Kolkata, India, 700014
        • Research Site
      • Kozhikode, India, 673008
        • Research Site
      • New Delhi, India, 110029
        • Research Site
  • Malaysia
      • Kajang, Malaysia, 43000
        • Research Site
      • Kota Bharu, Malaysia, 15586
        • Research Site
      • Kuala Lumpur, Malaysia, 59100
        • Research Site
      • Kuantan, Malaysia, 25100
        • Research Site
      • Malacca, Malaysia, 75400
        • Research Site
      • Sarawak Miri, Malaysia, 98000
        • Research Site
      • Sungai Buloh, Malaysia, 47000
        • Research Site
  • Philippines
      • Dagupan, Philippines, 2400
        • Research Site
      • Davao City, Philippines, PH-8000
        • Research Site
      • Mabalacat, Philippines, 2023
        • Research Site
      • Manadaluyong City, Philippines, 1552
        • Research Site
      • Quezon City, Philippines, 0870
        • Research Site
      • Roxas City, Philippines, 5800
        • Research Site
  • South Africa
      • Cape Town, South Africa, 7764
        • Research Site
      • Durban, South Africa, 4001
        • Research Site
      • Durban, South Africa, 4091
        • Research Site
      • Newton, South Africa, 2113
        • Research Site
      • Observatory, South Africa, 7925
        • Research Site
      • eMkhomazi, South Africa, 4170
        • Research Site
  • South Korea
      • Daegu, South Korea, 42415
        • Research Site
      • Gyeonggi-do, South Korea, 13620
        • Research Site
      • Incheon, South Korea, 21565
        • Research Site
      • Seoul, South Korea, 03722
        • Research Site
      • Seoul, South Korea, 04763
        • Research Site
  • Spain
      • Barcelona, Spain, 8035
        • Research Site
      • Madrid, Spain, 28041
        • Research Site
      • Majadahonda, Spain, 28222
        • Research Site
      • Palma de Mallorca, Spain, 07010
        • Research Site
  • Sweden
      • Linköping, Sweden, 587 58
        • Research Site
      • Lund, Sweden, 22185
        • Research Site
      • Örebro, Sweden, 70185
        • Research Site
  • Taiwan
      • Kaohsiung City, Taiwan, 80756
        • Research Site
      • Taichung, Taiwan, 40705
        • Research Site
      • Taipei, Taiwan, 100
        • Research Site
      • Taipei, Taiwan, 10449
        • Research Site
      • Taipei, Taiwan, 112
        • Research Site
      • Taipei, Taiwan, 110
        • Research Site
      • Taipei, Taiwan, 11696
        • Research Site
      • Taoyuan, Taiwan, 330
        • Research Site
      • Yunlin, Taiwan, 640
        • Research Site
  • Thailand
      • Bangkok, Thailand, 10400
        • Research Site
      • Chiang Mai, Thailand, 50200
        • Research Site
      • Hat Yai, Thailand, 90110
        • Research Site
      • Khlong Luang, Thailand, 12120
        • Research Site
      • Khon Kaen, Thailand, 40002
        • Research Site
  • United Kingdom
      • Birmingham, United Kingdom, B9 5SS
        • Research Site
      • Bradford, United Kingdom, BD9 6RJ
        • Research Site
      • Chesterfield, United Kingdom, S40 4AA
        • Research Site
      • Leeds, United Kingdom, LS9 7TF
        • Research Site
      • Liverpool, United Kingdom, L7 8YE
        • Research Site
      • London, United Kingdom, W6 7HY
        • Research Site
      • Penzance, United Kingdom, TR18 3DX
        • Research Site
      • Thetford, United Kingdom, IP24 1JD
        • Research Site
      • Wellingborough, United Kingdom, NN8 4RW
        • Research Site
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35209
        • Research Site
    • Arizona
      • Chandler, Arizona, United States, 85224
        • Research Site
    • California
      • Newport Beach, California, United States, 92663
        • Research Site
      • Sacramento, California, United States, 95817
        • Research Site
    • Florida
      • Lakeland, Florida, United States, 33813
        • Research Site
      • Miami, Florida, United States, 33126
        • Research Site
    • Georgia
      • Atlanta, Georgia, United States, 30344
        • Research Site
    • Indiana
      • Hammond, Indiana, United States, 46324
        • Research Site
    • Massachusetts
      • New Bedford, Massachusetts, United States, 02740
        • Research Site
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • Research Site
      • Southfield, Michigan, United States, 48075
        • Research Site
    • Missouri
      • Saint Charles, Missouri, United States, 63301
        • Research Site
    • Nevada
      • Las Vegas, Nevada, United States, 89106
        • Research Site
    • New Jersey
      • Union City, New Jersey, United States, 07087
        • Research Site
    • North Carolina
      • Charlotte, North Carolina, United States, 28207
        • Research Site
      • New Bern, North Carolina, United States, 28562
        • Research Site
      • Salisbury, North Carolina, United States, 28144
        • Research Site
      • Winston-Salem, North Carolina, United States, 27104
        • Research Site
    • Ohio
      • Columbus, Ohio, United States, 43207
        • Research Site
    • Texas
      • Boerne, Texas, United States, 78006
        • Research Site
      • El Paso, Texas, United States, 79902
        • Research Site
      • Houston, Texas, United States, 77074
        • Research Site
  • Vietnam
      • Da Nang, Vietnam, 55000
        • Research Site
      • Hanoi, Vietnam, 100000
        • Research Site
      • Ho Chi Minh City, Vietnam, 700000
        • Research Site
      • Hochiminh, Vietnam, 70000
        • Research Site
      • Huế, Vietnam, 530000
        • Research Site
      • Hà Nội, Vietnam, 100000
        • Research Site
      • Hồ Chí Minh, Vietnam, 700000
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. 18 to 80 years of age inclusive, at the time of signing the informed consent.

  2. Treated with medium-high dose ICS in combination with LABA at a stable dose for at least 28 days prior to Visit 1.

    Note: EU participants must be treated with high dose ICS in combination with LABA at a stable dose for at least 28 days prior to V1.

  3. Documented history of ≥ 1 severe asthma exacerbation within 1 year prior to Visit 1.
  4. Morning pre-BD FEV1 ≥ 40% predicted at Visit 1 and Visit 3.
  5. Able to perform acceptable lung function testing for FEV1 according to ATS/ERS 2019 acceptability criteria.
  6. Documented evidence of asthma in the 10 years up to or including Visit 1. A clinical diagnosis of asthma must be documented at least 12 months prior to Screening (Visit 1).
  7. An ACQ-6 score ≥ 1.5 at Visit 1 and at Visit 3.

9. Body weight of ≥ 40 kg and body mass index of < 35 kg/m2. 10. Contraceptive use by females should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. There are no restrictions on male participants or their female partners

At the end of the Run-in period (Visit 3), participants must fulfil the following additional criteria in order to be randomised into the study and enter the Treatment period:

  1. Pre-BD FEV1 ≥ 40%.
  2. A pre-BD/pre-IMP dose FEV1 at Visit 3 that has not increased or decreased by 20% or more from the pre-BD FEV1 recorded at Visit 1 and at Visit 2.
  3. An ACQ-6 score of ≥ 1.5.
  4. At least 80% compliance with usual asthma background medication during Run-in period (from Visit 2 to Visit 3) based on the daily asthma ePROs.
  5. Minimum 80% compliance with daily eCOAs (electronic Clinical Outcome Assessments) during the 14 days preceding Visit 3.
  6. For female of child bearing potential participants, a negative urine pregnancy test prior to administration of IMP.

Exclusion Criteria:

  1. A severe asthma exacerbation within 8 weeks prior to randomisation.
  2. History of herpes zoster reactivation.
  3. Participants with a significant COVID-19 illness within 6 months of enrolment.
  4. Clinically important pulmonary disease other than asthma.

  5. Any disorder, including, but not limited to, cardiovascular, gastrointestinal, hepatic, renal, neurological, musculoskeletal, infectious, endocrine, metabolic, haematological, psychiatric, or major physical impairment that is not stable in the opinion of the investigator and could:

    • affect the safety of the participant throughout the study,
    • influence the findings of the study or the interpretation, or
    • impede the participant's ability to complete the entire duration of study.
  6. Any clinically significant cardiac or cerebrovascular disease.
  7. History of venous thromboembolism.
  8. Participants who, as judged by the investigator, have evidence of active TB, or latent TB without completion of an appropriate course of treatment or appropriate ongoing prophylactic treatment.
  9. Participants with a recent history of, or who have a positive test for, infective hepatitis or unexplained jaundice, or participants who have been treated for HIV.
  10. Current or prior history of alcohol or drug abuse (including marijuana and marijuana containing valid prescriptions), as judged by the investigator.
  11. History of malignancy other than superficial basal cell carcinoma.
  12. Treatment with systemic corticosteroid within 4 weeks (oral) or 8 weeks (intramuscular) before Visit 1.
  13. Any immunosuppressive therapy within 12 weeks prior to Visit 1.
  14. Treatment with marketed biologics within 6 months of Visit 1 or 5 half-lives, whichever is longer.
  15. Inhaled corticosteroid plus fast-acting β2 agonist as a reliever is not allowed 15 days prior to Visit 1, during Screening/Run-in and throughout the Treatment period and preferably 1 week after the last dose of IMP.
  16. Live, attenuated, or mRNA vaccines within 4 weeks of Visit 1.
  17. Immunoglobulin or blood products within 4 weeks of Visit 1.
  18. Any immunotherapy within 6 months of Visit 1, except for stable maintenance dose allergen-specific immunotherapy started at least 4 weeks prior to Visit 1 and expected to continue through to the end of the Follow-up period.
  19. Concurrent enrolment in another interventional clinical study
  20. Participant treated with any investigational drug within 4 months or 5 half-lives, whichever is longer, prior to Visit 1.
  21. Participants with a known hypersensitivity to AZD4604 or any of the excipients of the product.
  22. Abnormal findings identified on physical examination, ECG, or laboratory testing.
  23. For female participants only - currently pregnant (confirmed with positive pregnancy test) or breast-feeding.
  24. Current smokers or participants with smoking history ≥ 10 pack-years.
  25. Participants with a known long-term exposure to occupational asbestos, silica, radon, heavy metals, and polycyclic aromatic hydrocarbons.
  26. Positive family history of primary lung cancer in first degree relatives (mother, father, sisters, brothers and children).
  27. Positive urine cotinine test or exhaled carbon monoxide test at Visit 1 and at any timepoint throughout the study.
  28. Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site).
  29. Judgement by the investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions, and requirements.
  30. Donation of blood (≥ 450 mL) within 3 months or donation of plasma within 14 days before Visit 1.
  31. Major surgery within 8 weeks prior to Visit 1, or planned inpatient surgery, major dental procedure or hospitalisation during Screening, Treatment, or Follow-up periods.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Arm 2
Placebo
Other: Placebo
Placebo
Experimental: Arm 1
AZD4604
Drug: AZD4604
AZD4604

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to first CompEx Asthma event
Time Frame: 12 weeks
CompEx Asthma is a composite surrogate endpoint for exacerbations that captures: - acute worsening events based on a combination of events based on ePRO data (asthma symptoms and rescue medication use), PEF data, and severe asthma exacerbation events.
12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pre-BD FEV1
Time Frame: 12 weeks
Change from baseline in pre-bronchodilator forced expiratory volume in 1 second.
12 weeks
CAAT
Time Frame: 12 weeks
Change from baseline in the Chronic Airways Assessment Test (CAAT). The CAAT is an 8-item patient-reported outcome measure developed to measure health status in patients with asthma and COPD.
12 weeks
ACQ-6
Time Frame: 12 weeks
Change from baseline in the Asthma Control Questionnaire 6 (ACQ-6). The ACQ-6 has 6 questions (regarding asthma symptoms and rescue bronchodilator use). Answering the questions results in a score out of 6. A Score of 0 indicates complete control and 6 reflects severely uncontrolled disease.
12 weeks
Time to first CompEx acute worsening event
Time Frame: 12 weeks
Time to first CompEx Asthma acute worsening event.
12 weeks
CompEx event rate
Time Frame: 12 weeks
The number of CompEx Asthma events recorded in the 12-week period.
12 weeks
CompEx acute worsening event rate
Time Frame: 12 weeks
The number of CompEx Asthma acute worsening events recorded in the 12-week period.
12 weeks
Average morning and average evening PEF
Time Frame: 12 weeks
Change from baseline in 2-weekly average morning and evening Peak Expiratory Flow (PEF).
12 weeks
Daily asthma symptom score (total, daytime, and night-time)
Time Frame: 12 weeks
Change from baseline in 2-weekly average Daily asthma symptom score. Asthma symptoms are assessed (0 to 3 scale) twice daily, once in the morning and once in the evening.
12 weeks
FeNO
Time Frame: 12 weeks
Change from baseline in FeNO at Week 4 and Week 12.
12 weeks
Cough
Time Frame: 12 weeks
Change from baseline in cough severity at Week 4 and Week 12. This will be measured by Cough Severity Item Visual Analogue Scale, a 100-point linear scale marked with a horizontal or vertical line by the participant between the 2 extremes. Zero represents no cough while 100 represents worst cough imaginable.
12 weeks
PK
Time Frame: 12 weeks
AZD4604 plasma concentration pre- and post-dose at Week 4, pre-dose at Week 12.
12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

AstraZeneca

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 16, 2023

Primary Completion (Actual)

October 28, 2025

Study Completion (Actual)

October 28, 2025

Study Registration Dates

First Submitted

August 25, 2023

First Submitted That Met QC Criteria

August 25, 2023

First Posted (Actual)

August 31, 2023

Study Record Updates

Last Update Posted (Estimated)

November 13, 2025

Last Update Submitted That Met QC Criteria

November 12, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • D8210C00003

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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