Rosiglitazone Versus Theophylline in Asthmatic Smokers

Inclusion Criteria: * Males or females between 18 and 60 years of age (inclusive). * Clinical diagnosis of mild or moderate persistent asthma in accordance with the Global Initiative for Asthma (GINA) criteria * Have had a history of asthma for a minimum of 6 months prior to entry into the study * Subjects must be current cigarette smokers with a minimum five-pack-year smoking history * Baseline FEV1 that is greater than 50% predicted; and reversibility of 12% or more at screening, washout or randomisation. * Capable of providing signed written informed consent and complying with all the specified study procedures. Exclusion Criteria: * Asthma exacerbation or a respiratory tract infection within four weeks of screening. * Type 1 or type 2 diabetes mellitus. * Women who are lactating, pregnant, or planning to become pregnant. * Clinically significant renal or hepatic laboratory values (e.g. AST/ALT/total bilirubin/AP \> 2.5 times normal values). * Anaemia (\< 11 g/dL for males or \< 10 g/dL for females) * Contraindications to treatment as outlined in any of the product labels * Prior history of severe oedema or serious fluid related event (e.g., heart failure) associated with any TZD * The subject has a history of significant hypersensitivity to study drugs * Presence of unstable or severe angina or congestive heart failure (NYHA class III/IV) or evidence or history of known congestive heart failure (NYHA class I-IV) or an abnormal electrocardiogram (ECG), as determined by the Investigator, or subjects who have had new cardiac events (such as MI, new CHF, PTCA, CABG) within 6 months of screening. * History or suspicion of current drug abuse or alcohol abuse within the last 6 months. * History suggestive of active infection or non-asthma lung pathology * Clinically significant renal disease, metabolic syndrome, cirrhosis (Child-Pugh Class B/C), hypertension or any other clinically significant cardiovascular, neurological, endocrine, or haematological abnormalities that are uncontrolled on permitted therapy. * Risk factors for human immunodeficiency virus (HIV), hepatitis B or hepatitis C infection at Screening (Visit 1) * Subjects who are morbidly obese, defined as having a body mass index (BMI) \> 40 kg/m2 * Unable to perform spirometry * Subjects who require treatment with any of the following asthma medications from Screening (Visit 1) until study completion: * Inhaled cromolyn sodium or nedocromil; * Ipratropium bromide; * Xanthines (theophylline preparations); * Leukotriene modifiers; * Long-acting inhaled beta2-agonists (salmeterol, formoterol); * Oral beta2-agonists. * Treatment with oral, intravenous or intra-articular corticosteroids within 6 weeks of Screening or thereafter. * Subjects who have been taking in excess of 1000 μg daily of beclomethasone (or equivalent) within 6 weeks of Screening