The primary purpose of this study was to investigate the efficacy of levalbuterol compared to a placebo and compared to albuterol in the treatment and prevention of bronchoconstriction in adolescent and adult subjects with asthma, with all treatments administered 4 times a day (QID).

This was a Phase III, multicenter, randomized, double-blind, placebo- and active-controlled, parallel-group study of up to 9 weeks in duration. Seven days of QID single-blind placebo administration (via MDI) was followed by 56 days of QID double-blind active treatment. Following the run-in period, each subject was randomized to one of the following three treatments: levalbuterol HFA MDI 90 mcg (2 actuations of 45 mcg), racemic albuterol HFA MDI 180 mcg (2 actuations of 90 mcg), or placebo (2 actuations). Subjects were randomized in a 2:1:1 ratio of levalbuterol to racemic albuterol to placebo. In order to maintain blinding of the device, a placebo dose was administered with each treatment. This study was previously posted by Sepracor Inc. In October 2009, Sepracor Inc. was acquired by Dainippon Sumitomo Pharma., and in October 2010, Sepracor Inc's name was changed to Sunovion Pharmaceuticals Inc.

Inclusion Criteria

• Willing and able to comply with the study procedures and visit schedules
• Male or female, at least 12 years of age
• Female subjects 12-60 years of age must have a negative serum pregnancy test at study start.
• Women of child bearing potential must be using an acceptable method of birth control
• Have a documented diagnosis of asthma for a minimum of 6 months prior to study start
• Must have stable baseline asthma and have been using a B-adrenergic agonist, and/or anti-asthma anti-inflammatory medication, and/or OTC asthma medication for at least 6 months prior to study start
• Must be in good health with the exception of their reversible airways disease and not suffering from any chronic condition that might affect their respiratory function
• Must have a chest X-ray that is not diagnostic of pneumonia, atelectasis, pulmonary fibrotic disease, pneumothorax, chronic obstructive pulmonary disease, etc.
• Must be able to complete the diary cards and medical event calendars reliably on a daily basis, understand dosing instructions, and demonstrate how to use the MiniWright PEF meter.

Exclusion Criteria

• Female subject who is pregnant or lactating
• Have participated in an investigational drug study within 30 days prior to study start, or who is currently participating in another clinical trial
• Subject whose schedule prevents him or her from taking the first daily dose of study medication and/or starting study visits before 9 AM
• Subject who has travel commitments during the study that would interfere with trial measurements or compliance
• Have a history of hospitalization for asthma within 45 days prior to study start, or who is scheduled for in-patient hospitalization, including elective surgery
• Have a known sensitivity to levalbuterol or racemic albuterol, or any excipients in any of these formulations
• Subject using any prescription drug with which albuterol sulfate administration is contraindicated
• Subject with currently diagnosed life-threatening asthma
• History of cancer (exception: basal cell carcinoma in remission).
• Subject with hyperthyroidism, diabetes, hypertension, cardiac diseases or seizure disorders that currently are not well controlled by medication
• History of substance abuse or drug abuse within 12 months preceding study start
• Subject with greater than 10 pack year history of cigarette smoking or use of any tobacco products within 6 months of study start
• Documented history of bronchopulmonary aspergillosis or any form of allergic alveolitis
• Have suffered from a clinically significant upper or lower respiratory tract infection in the 2 weeks prior to study start
• Subject who is a staff member or relative of a staff member