Bioequivalence Study to Compare Fluticasone Furoate (FF) 1-strip Inhaler With FF 2-strip Inhaler and With FF/Vilanterol Combination

Fluticasone furoate (FF; GW685698), a novel corticosteroid, is being developed both as a monotherapy for the treatment of asthma and in combination with vilanterol (VI; GW642444) for the treatment of asthma and COPD. The novel dry powder inhaler (NDPI) will be used to deliver both FF monotherapy and the FF/VI combination. The NDPI can be used with either a single strip or two strips, the single strip being used for FF monotherapy and two strips being used to deliver the FF/VI combination. In some previous FF monotherapy studies, including the phase IIB programme, conducted using the NDPI, the inhaler contained two strips (FF in the first strip and matched VI placebo in the second strip). This two strip configuration has been used for the majority of FF monotherapy treatment arms in previous and ongoing studies. The aim of this study is to determine the bioequivalence of FF monotherapy (single strip) compared with FF monotherapy (two strip), and to determine the bioequivalence of FF monotherapy (single strip) compared with FF/VI, administered via the NDPI. This data will facilitate the inclusion of FF monotherapy (two strip) data and FF/VI combination data to support the FF monotherapy product development. This will be a randomised, open-label, replicate, six-way crossover, single dose study in healthy male and female subjects. Thirty healthy male and female subjects will be enrolled in this study to ensure twenty-four evaluable subjects. Pharmacokinetic samples will be taken over 36 hours. Safety will be assessed by adverse event (AE) monitoring throughout the study.