A Phase 2 interventional study of Tozorakimab and Placebo in Asthma, sponsored by AstraZeneca. Recruiting at 223 sites in 21 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-30.
Sponsored by AstraZeneca · Phase 2, Interventional, and Treatment
This is a dose-range finding, double-blind, placebo-controlled, phase IIb study designed to assess efficacy and safety of tozorakimab administered subcutaneously in adult participants with uncontrolled asthma receiving medium-to-high dose inhaled corticosteroids.
4,841 studies on the registry are indexed under Asthma; 600 are open to participants now.
This study's planned enrollment of 540 is above the median of 78 across 3,341 interventional studies indexed under Asthma.
Browse Asthma studies →AstraZeneca is the lead sponsor of 3,499 studies on the registry; 270 are open to participants now.
Of its 368 completed or terminated interventional studies of FDA-regulated products, 178 (48%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Sep 25, 2026. See what changed
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.
Documented exacerbation history in the last 12 months and biomarker requirements of:
(i) Eosinophils ≥ 150 cells/µl or (ii) FeNo ≥ 25 ppb
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.
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.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
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.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
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.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dosing subcutaneously tozorakimab Dose 1
Drug: Tozorakimab
Dosing subcutaneously tozorakimab Dose 2 and placebo
Drug: Tozorakimab
Dosing subcutaneously with equivalent volume to tozorakimab
Drug: Placebo
The drug will be administered subcutaneously.
Placebo will be administered subcutaneously.
Annualised rate of severe asthma exacerbations
The rate ratio of severe asthma exacerbations will be assessed in the participants with uncontrolled moderate-to-severe asthma and ≥ 1 severe exacerbation within 12 months prior to screening.
Time frame: Over 26 to 52 weeks
Annualised rate of severe asthma exacerbations
The rate ratio of severe asthma exacerbations will be assessed in the participants with uncontrolled moderate-to-severe asthma and baseline eosinophils \< 300 cells/µL and history of ≥2 severe exacerbations within 12 months prior to screening.
Time frame: Over 26 to 52 weeks
Time to first severe asthma exacerbation
To evaluate the effect of two dose levels of tozorakimab compared to placebo on time to first severe asthma exacerbations.
Time frame: Over 26 to 52 weeks
Change from baseline in pre-bronchodilator forced expiratory volume in 1 second (FEV1)
Difference in mean change from baseline between tozorakimab and placebo.
Time frame: Over weeks 20 to 26
Change from baseline in post-bronchodilator FEV1
Difference in mean change from baseline between tozorakimab and placebo.
Time frame: At week 26
Change from baseline in the Asthma Control Questionnaire 6 (ACQ-6)
Difference in mean change from baseline between tozorakimab and placebo. 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.
Time frame: At week 26
Change from baseline in the Asthma Quality of Life Questionnaire for 12 Years and Older (AQLQ12+)
Difference in mean change from baseline between tozorakimab and placebo. The AQLQ12+ includes 32 questions grouped into four domains: symptoms; activity limitations; emotional function; and, environmental stimuli. Each question is scored on a seven-point Likert scale, which ranges from 7 (no impairment) to 1 (severe impairment). The overall score is calculated as the mean of all questions, and the four domain scores are the means of the scores for the questions in the respective domains.
Time frame: At week 26
Trough serum concentrations of tozorakimab
Pharmacokinetics: concentrations of tozorakimab in trough serum.
Time frame: Over 52 weeks
Anti-drug antibody incidence
Immunogenicity: Number of Participants With Positive Antibodies to tozorakimab
Time frame: Over 52 weeks
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Showing the first 100 of 223 sites across 21 countries. Choose a country and city above to see the rest.
Plan to share: Yes — Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.
Supporting information: Study protocol, Statistical analysis plan
Time frame: AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA PhRMA Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.
Access criteria: When a request has been approved AstraZeneca will provide access to the anonymized individual patient-level data via secure research environment Vivli.org. Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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Studies of the drug tested here: Tozorakimab