Randomized, Placebo-controlled Study Comparing Efficacy of Fluticasone/Salmeterol Combination to Advair in Asthmatics

Inclusion Criteria: * Adult male or female subjects of non-childbearing or of childbearing potential committed to consistent and correct use of an acceptable method of birth control * Diagnosed with asthma, as defined by the National Asthma Education and Prevention Program (NAEPP),5 at least 6 months prior to screening * Moderate-to-severe asthma with a pre-bronchodilator FEV1 of \>45% and \<85% of predicted normal, measured at least 6 hours after short-acting β agonist (SABA)and at least 24 hours after the last dose of long-acting β agonist (LABA), at the screening visit and on the day of treatment * \>15% and \>0.20 L reversibility of FEV1 within 30 minutes following 360 mcg of albuterol inhalation (pMDI) * Patients should be stable on their chronic asthma treatment regimen for at least 4 weeks prior to enrollment * Currently non-smoking; having not used tobacco products (i.e., cigarettes, cigars, pipe tobacco) within the past year, and having \< 10 pack-years of historical use * Able to replace current regularly scheduled short-acting β agonists (SABAs) with salbutamol/albuterol inhaler for use only on an as-needed basis for the duration of the study (subjects should be able to withhold all inhaled SABAs for at least 6 hours prior to lung function assessments on study visits) * Willing to discontinue their asthma medications (inhaled corticosteroids and long-acting β agonists) during the run-in period and for the remainder of the study * Willingness to give their written informed consent to participate in the study Exclusion Criteria: * Life-threatening asthma, defined as a history of asthma episodes(s) requiring intubation, and/or associated with hypercapnia, respiratory arrest or hypoxic seizures, asthma-related syncopal episodes(s), or hospitalizations within the past year or during the run-in period * Significant respiratory disease other than asthma (chronic obstructive pulmonary disease (COPD), interstitial lung disease, etc.) * Evidence or history of clinically significant disease or abnormality including congestive heart failure, uncontrolled hypertension, uncontrolled coronary artery disease, myocardial infarction, or cardiac dysrhythmia. In addition,historical or current evidence of significant hematologic, hepatic, neurologic, psychiatric, renal, or other diseases that, in the opinion of the investigator, would put the patient at risk through study participation, or would affect the study analyses if the disease exacerbated during the study * Patients who required systemic corticosteroids (for any reason) within the past 4 weeks * Hypersensitivity to any sympathomimetic drug (e.g., formoterol or albuterol) or any inhaled, intranasal, or systemic corticosteroid therapy * Patients currently receiving β-blockers