Evaluating the Efficacy and Safety of Fluticasone Furoate in the Treatment of Asthma in Adults and Adolescents

This will be a multi-centre, randomised, double-blind, parallel-group study. Subjects meeting all the inclusion criteria and none of the exclusion criteria during Visit 1 (screening visit) will enter a four week Run-In period during which they will remain on their baseline ICS medication. In addition, all subjects will be provided with albuterol/salbutamol for relief of asthma symptoms. Subjects failing screening will not be eligible for re-screening. During the Run-In and double-blind treatment periods subjects will maintain an electronic daily diary to record morning and evening Peak Expiratory Flow (PEF), asthma symptom score and rescue albuterol/salbutamol use. Subjects will receive a contact (Phone Contact 1/optional office visit (1b)) during Run-In to reinforce compliance with Run-In medication and diary monitoring. Those subjects who meet the eligibility criteria at the end of the Run-In period will be stratified in an approximately 1:1 ratio according to their baseline FEV1 as a percentage of predicted normal - one stratum for those with FEV1 percent predicted ≥40% to ≤65% and one for those with FEV1 percent predicted \>65% to ≤90%. Once stratified, subjects will be randomised to one of the following treatments and enter into a 24 week double-blind treatment period:1) Fluticasone furoate 100mcg once daily in the evening or 2) Fluticasone furoate 200mcg once daily in the evening. Subjects will then attend 6 on-treatment visits at Visits 3, 4, 5, 6, 7 and 8 (Weeks 2, 4, 8, 12, 18 and 24 respectively). All visits including Visit 1 must be conducted in the evening between 5 PM and 11 PM. Subjects will receive treatment for 24 weeks. Twenty four hour urinary cortisol assessments will be collected at the end of Run-In (Visit 2) and at end of treatment (Visit 8) visits. A follow-up contact will be performed 1-week after completing study medication (Visit 9). Subjects will participate in the study for up to a maximum of 29 weeks (including screening, treatment and follow-up contact). In addition, partially used NDPIs will be collected in a subset of subjects. For subjects who have consented for pharmacogenetics, a blood sample will also be taken for pharmacogenetic analysis.