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.