The purpose of this study is to evaluate the effect of 2 different GP metered dose inhaler (MDI) doses relative to placebo MDI as add-on treatment to BFF MDI on lung function in participants 4 to less than 12 years of age with asthma.

This is a Phase II, multi-center, randomized, double-blind, 3-period, 6-sequence crossover study evaluating two doses of GP Metered-Dose Inhaler (MDI) compared with placebo MDI as add-on therapy to BFF MDI.

The study comprises a 3-week run-in period, followed by three 3-week treatment periods where participants will be randomized to one of six treatment sequences, and a safety follow-up visit 12 to 16 days after the last dose of study intervention.

The treatment periods are as follows:

• Treatment A: BFF MDI + GP MDI Dose A
• Treatment B: BFF MDI + GP MDI Dose B
• Treatment C: BFF MDI + Placebo MDI

Main Inclusion Criteria:

• Participants who have a documented history of physician-diagnosed asthma
• Participants who have been using a stable and regular inhaled corticosteroid plus one additional asthma controller medication.
• Participants must have a Childhood Asthma Control Test score ≥ 19.
• Participants must have a pre-bronchodilator FEV1 ≤ 95% of predicted normal value.
• Body mass index (BMI) ≤ 95 percentile for age and body weight of ≥ 14 kg or higher.
• Female participants who experience menarche must have a negative urine pregnancy test.
• Received no asthma medication other than run-in BFF MDI BID and albuterol/salbutamol as needed.

Main Exclusion Criteria:

• Life-threatening asthma defined as a history of significant asthma episode(s) requiring intubation associated with hypercapnia, respiratory arrest, hypoxic seizures, or asthma-related syncopal episode(s).
• Historical or current evidence of a clinically significant disease including, but not limited to cardiovascular, hepatic, renal, hematological, neurological, endocrine, gastrointestinal, or pulmonary.
• Any clinically relevant abnormal findings in physical examination, clinical chemistry, hematology, vital signs, or ECG.
• Hospitalization for asthma
• Narrow-angle glaucoma not adequately treated and/or change in vision, bladder dysfunction, bladder outlet obstruction/urinary retention or any other conditions where anticholinergic treatment is contraindicated and may be relevant.
• Use of Long-acting muscarinic antagonist (LAMA), either alone or as part of an inhaled combination therapy.
• Current use of any systemic beta-blockers.
• Respiratory infection involving antibiotic treatment.
• Systemic corticosteroid use for any reason (including asthma exacerbations).
• Participants with a known hypersensitivity to beta 2-agonists, corticosteroids, anticholinergics, or any component of the MDI.
• Participants who are medically unable to withhold their short-acting bronchodilators and other asthma medications.
• Any use of marketed (eg, omalizumab, mepolizumab, benralizumab, reslizumab) or investigational biologic.
• Regular use of a nebulizer or a home nebulizer for receiving asthma medications.
• Use of any immunomodulators or immunosuppressive medication.

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 athttps://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.