Evaluating the Efficacy and Safety of Fluticasone Furoate/Vilanterol Trifenatate in the Treatment of Asthma in Adolescent and Adult Subjects of Asian Ancestry.

This will be a randomised, double-blind, placebo controlled, parallel group, multi-centre study. At Visit 1 (Screening Visit) subjects who meet all of the inclusion criteria and none of the exclusion criteria will enter a two week run-in period. Subjects will remain on their current ICS therapy throughout the run-in period. At the end of the run-in period (Visit 2) subjects meeting the Randomisation criteria will enter a 12 week treatment period and receive one of the two following treatments: 1) FF/VI (100/25mcg) administered once daily in the evening via a Novel Dry Powder Inhaler (NDPI) 2) Placebo administered once daily in the evening via a NDPI In addition, all subjects will be supplied with albuterol/salbutamol inhalation aerosol to be used as required to treat asthma symptoms. Subjects who have not met the randomisation criteria at Visit 2 will be withdrawn from the study. Subjects meeting the randomisation criteria will be randomized to one of the two treatment groups and will attend the clinic for 3 on-treatment visits at Week 4 (Visit 3), Week 8 (Visit 4) and Week 12 (Visit 5). Subjects will receive treatment for 12 weeks. A Follow-up Visit or phone call (Visit 6) will take place 1 week after completing study medication. All clinic visits will take place in the morning. Subjects will participate in the study for a maximum of 15 weeks (Screening to Follow-up inclusive). A subject is regarded to have completed the study if they complete all phases of the study (Screening, treatment, Follow-up).