Oral GW766944 (Oral CCR3 Antagonist)

This will be a multi-centre study. This is a randomized, double-blind, placebo-controlled, parallel-group study, in patients with asthma and eosinophilic bronchitis. Subjects with asthma will be atopic and not on oral prednisone. Inhaled corticosteroids are allowed if on stable dose. All subjects will receive a 5 day course of 30mg daily of oral prednisone after one week stopping study drug. All subjects will attend screening (Visit 1) at which their eligibility for inclusion will be assessed. Eligible subjects will be randomized to receive either 300 mg of GW766994 twice daily or matching placebo at Day 1 (Visit 2) and will be stratified according to the subject's sputum eosinophil count at Visit 1. Treatment will be 10 days of oral dosing, and subjects will participate in a Day 7 or 8 visit (Visit 3), Day 10 visit (Visit 4 - End of Treatment), followed by a 1 week wash out period (Visit 5 -Follow Up Visit). At Visit 5, all subjects will be given 30 mg oral daily prednisone for 5 days and subjects to return to clinic at a Post Oral Prednisone Visit (Visit 6) at Day 22. Pharmacodynamic assessments will include both sputum and blood biomarkers and spirometry. Safety will be assessed by vital sign measurement, electrocardiogram, clinical laboratory tests (hematology, chemistry \& urinalysis), clinical monitoring and adverse event reporting. Pharmacokinetic samples will be collected from each subject according to the sample schedule in the timing and events table. Study will involved sputum biology (progenitors, cell counts). Study will be conducted in Canada only.