• area under the FEV1 percent change curve from visit pre-dose and from study baseline curves averaged over the double-blind period [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• peak percent change in FEV1 from study baseline [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• peak change in FEV1 from visit predose [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• peak percent of predicted FEV1 [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• area under the FEV1 curve (AUC) [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• peak change and peak percent change in FEF25-75% from visit predose [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]
• peak change and peak percent change in FVC from visit predose [ Time Frame: Weeks 0, 4, 8 ] [ Designated as safety issue: No ]

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.

• Drug: levalbuterol tartrate MDI
• Drug: racemic albuterol MDI
• Drug: Placebo

• Experimental: levalbuterol MDI 90 mcg QID
• Active Comparator: racemic albuterol MDI 180 mcg QID
• Placebo Comparator: Placebo MDI QID

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