Phase 2a, AMP Challenge, Dose Escalation Study to Assess the Dose Response for Topical Efficacy and Systemic Activity in Asthmatic Subjects

This is a randomized, placebo-controlled, 2-period crossover, escalating repeat dose study, aiming to investigate whether higher potency of different inhaled corticosteroid confers an improvement in the topical efficacy to systemic activity ratio in asthmatic subjects. It will compare the dose response for topical efficacy via airway responsiveness (to adenosine-5'-monophosphate [AMP] challenge), and the dose response for systemic activity via 24 hour plasma cortisol suppression, and thereby compare the relative therapeutic index, for the following inhaled corticosteroids: fluticasone furoate (FF), fluticasone propionate (FP) and budesonide (BUD). There will be a screening visit 4 - 42 days before the first dose of study treatment, and AMP challenge Provocative concentration 20 (PC20) of <=80 milligrams per milliliter (mg/mL) at screening visit 2 i.e. at 4 - 14 days before the first dose of study treatment. Subjects will be randomized to one of 5 or 12 treatment sequences, and will have one or two treatment periods, each comprising 5 consecutive 7-day phases of escalating doses of either FF, FP, BUD or placebo. There will be a 25- to 42-day washout period between treatment periods. The study duration for each subject will be approximately 13 or 24 weeks including the follow-up period.

Inclusion Criteria - Subjects must be 18 to 65 years of age inclusive, at the time of signing the informed Consent. - Documented history of bronchial asthma, first diagnosed at least 6 months prior to the screening visit - Pre-bronchodilator FEV1 >=65% of predicted at screening; the pre-dose baseline FEV1 should not have changed significantly in the opinion of the investigator from the screening baseline value and should be >=65% predicted for the subject to continue - Documented sensitivity to AMP with a provocative concentration of AMP resulting in a fall of >=20% FEV1 with a PC20 AMP =12 inhalations/day of salbutamol were used; or no severe asthma exacerbations requiring use of systemic corticosteroids (tablets, suspension, or injection) or an in-patient hospitalization or emergency department visit due to asthma that required systemic corticosteroids; or no clinical asthma worsening which in the opinion of the investigator requires additional asthma treatment other than study medication or salbutamol; subjects taking Long-acting beta2-agonist (LABA), long-acting muscarinic antagonist (LAMA), leukotriene receptor antagonist (LTRA) therapy within three months prior to the start of the study are not eligible; subjects taking biological therapies within 6 months prior to start of the study are not eligible. - Bodyweight >=50 Kilogram (kg) and BMI within the range 18.0-35.0 kg/meter (m)^2 (inclusive) - Male and female. Females: A female subject is eligible to participate if she is not pregnant (as confirmed by a negative urine human chorionic gonadotrophin [HCG] test), not lactating, and at least one of the following conditions applies prior to randomization: • Non-reproductive potential defined as pre-menopausal females with one of the following: Documented tubal ligation; Documented hysteroscopic tubal occlusion procedure with follow-up confirmation of bilateral tubal occlusion; Hysterectomy; Documented Bilateral Oophorectomy; Postmenopausal defined as 12 months of spontaneous amenorrhea, in questionable cases a blood sample with simultaneous follicle stimulating hormone (FSH) and estradiol levels consistent with menopause. Females on hormone replacement therapy (HRT) and whose menopausal status is in doubt will be required to use one of the highly effective contraception methods if they wish to continue their HRT during the study. Otherwise, they must discontinue HRT to allow confirmation of post-menopausal status prior to study enrolment. • Reproductive potential and agrees to follow one of the highly effective methods for avoiding pregnancy in females of reproductive potential from 30 days prior to the first dose of study medication and until at least five terminal half-lives after the last dose of study medication. The investigator is responsible for ensuring that subjects understand how to properly use these methods of contraception. - Aspartate aminotransferase and Alanine transaminase 1.5xULN is acceptable if bilirubin is fractionated and direct bilirubin 20 cigarettes per week or the equivalent unit dose of other tobacco products or e-cigarettes, or smokers with a smoking history of >=10 pack years. - History of regular alcohol consumption exceeding 21 units per week for men and 14 units per week for females (1 unit =5 ounces [150 mL] of wine or 12 ounces [360 mL] of beer or 1.5 ounces [45 mL] of spirits) within 6 months of screening. - All subjects who are currently or in the last month have worked night-shifts are excluded from the study - Exposure to more than four new chemical entities within 12 months prior to the first dosing day or received an investigational product within 30 days of study start, or 5 half-lives of study drug if that is longer. - A subject has any clinically significant, uncontrolled condition or disease state that, in the opinion of the investigator, would put the safety of the subject at risk through study participation or would confound the interpretation of the study results if the conditi