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.

Inclusion Criteria:

1. Provision of signed and dated written informed consent prior to any study-specific procedures.

2. Adults aged 18-75, inclusive when signing the informed consent.

3. Documented physician-diagnosis of asthma for at least 12 months.

4. Treated with medium or high dose ICS in combination with LABA.

5. Demonstration of uncontrolled asthma through ACQ-6 score ≥ 1.5 .

6. Pre-bronchodilator FEV1 ≥ 40% to ≤ 90% of predicted normal.

7. Documented exacerbation history in the last 12 months and biomarker requirements of:

   1. 2 severe exacerbations OR
   2. 1 severe exacerbation and:

   (i) Eosinophils ≥ 150 cells/µl or (ii) FeNo ≥ 25 ppb

8. Participants need to demonstrate a ≥70% compliance for Asthma Daily Diary.

9. Women of Child Bearing Potential (WOCBP) must have a negative pregnancy test.

10. Contraceptive use by males and females should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

Exclusion Criteria:

1. Completed treatment for respiratory infection with antibiotics in the 4 weeks prior to Visit 1.
2. Clinically significant pulmonary disease other than asthma .
3. Current smokers, former smokers with >10 pack-years history.
4. Clinically significant aortic stenosis or pulmonary arterial hypertension.
5. Active tuberculosis, hepatitis, HIV, or current diagnosis of cancer or immune complex disease.
6. Unstable cardiovascular disorders.

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.

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.

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.