Efficacy and Safety Study of GSK3772847 in Subjects With Moderately Severe Asthma

Inclusion Criteria

• Age: At least 18 years of age at the time of signing the informed consent.
• Males and females: A female subject is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies: Not a woman of childbearing potential (WOCBP) OR A WOCBP who agrees to follow highly effective contraceptive methods from 4 weeks prior to the first dose of study medication and until at least 16 weeks after the last dose of study medication and completion of the follow-up visit.
• Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the consent form and in this protocol.
• A subject with a documented diagnosis of moderate severe asthma based on Global Initiative for Asthma (GINA) 2016 Guidelines, whose asthma has been managed with regular treatment of high dose ICS defined as FP 500 mcg twice daily (i.e. 1000 mcg total daily dose) or equivalent, and LABA for at least 4 months. Additional therapy with a leukotriene receptor antagonist (LTRA) is permissible.
• Airway reversibility of at least 12 percent and 200 milliliter (mL) in FEV1 at Screening (Visit 1), or documented reversibility prior to Screening (Visit 1), or documented history of bronchial hyper reactivity (e.g. fall in FEV1 from baseline of more than or equal to 20percent with standard doses of methacholine or histamine, or more than or equal to 15 percent with standardized hyperventilation, hypertonic saline or mannitol challenge) from a bronchoprovocation study [e.g. methacholine challenge prior to Screening (Visit 1)].
• ACQ-5 score more than or equal to 1.0 and less than 4.0 at Screening (Visit 1).
• Had at least one asthma exacerbation within 12 months prior to screening that required treatment with systemic corticosteroid and/or hospitalization.
• All subjects must be able to replace their current Short-Acting Beta2-Agonists (SABA) treatment with albuterol/salbutamol aerosol inhaler at Visit 1 for use as needed, per product label, for the duration of the study.

Randomization inclusion criteria:

• ACQ-5 score more than or equal to 1.0 and less than 4.0 at Visit 2.
• Compliance with completion of the Daily eDiary reporting defined as completion of all questions/assessments on more than or equal to 4 of the last 7 days during the run-in period.

Exclusion Criteria

• Current smokers or former smokers with a smoking history more than or equal to 10 pack years.
• Presence of a known pre-existing, clinically important respiratory conditions (e.g. pneumonia, pneumothorax, atelectasis segmental or larger, pulmonary fibrotic disease, bronchopulmonary dysplasia, chronic bronchitis, emphysema, chronic obstructive pulmonary disease, or other respiratory abnormalities) other than asthma.
• A pre-bronchodilator FEV1 less than 50 percent predicted of normal value at Screening (Visit 1).
• Subjects with a diagnosis of malignancy or in the process of investigation for a malignancy. Subjects with carcinoma that have not been in complete remission for at least 5 years. Subjects who have had carcinoma in situ of the cervix, squamous cell carcinoma and basal cell carcinoma of the skin would not be excluded based on the 5 year waiting period if the subject has been considered cured by treatment.
• Presence of hepatitis B surface antigen (HBsAg), positive hepatitis C antibody test result at Screening (Visit 1) or within 3 months prior to first dose of study treatment.
• Site investigators will be provided with ECG over-read conducted by a centralized independent cardiologist, to assist in evaluation of subject eligibility.
• Weight: less than 50 kilograms (kg) and more than 150 kg.
• Regular use of systemic corticosteroids for conditions including asthma within 3 months prior to Screening (Visit 1).
• Subjects with high parasympathetic tone (e.g. trained athletes with baseline bradycardia) or chronic conditions associated with parasympathetic surges (e.g. migrain