This study will evaluate efficacy (FEV1), safety, tolerability, pharmacodynamics and pharmacokinetics of single and repeat inhaled doses of GW642444. This will be a multi-centre, double-blind, placebo controlled, dose ascending, four way cross-over study in approximately 28 mild to moderate asthmatic subjects.

Key assessments: Efficacy, safety, tolerability, pharmacodynamics and pharmacokinetics will be assessed by measurement of FEV1, blood pressure, heart rate, 12-lead ECGs, clinical laboratory tests, collection of adverse events (AE) information and blood samples.

Inclusion criteria:

• Female subjects must be non-childbearing (i.e., surgically sterilised or post-menopausal).
• Non-smokers for at least 6 months.
• Stable asthma.

Exclusion criteria:

• Abnormal findings on heart monitoring assessment.
• Lower respiratory tract infection within 4 weeks, upper respiratory tract within 2 weeks of study.
• Currently taking doses of fluticasone propionate over 500mcg/day.
• Unstable asthma medication.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.