• Change in Forced Expiratory volume in 1 s (FEV-1) over 12 weeks recorded in electronic diary
  

• Other pulmonary function tests including forced vital capacity (FVC) and peak expiratory flow rate (PEFR).
  
• Clinical endpoints (frequency of asthma exacerbations and patient data captured in diary including daily morning and evening PEFR).
  
• Safety variables include adverse events, ECGs, clinical laboratory tests and vital signs.
  

• Ages eligible for study: 12 years and above
• Genders eligible for study: both
• Prior steriod use: steroid-requiring or steroid-free

Inclusion Criteria:

• History of asthma for at least 12 months
• For steriod-requiring patients, documented use of inhaled corticosteroid for at least 4 weeks prior to Screening Visit
• For steroid-free patients, no history of inhaled steroid asthma medication for at least 12 weeks prior to Screening Visit
• Demonstrate FEV-1 of 60-85% of predicted normal values at Screening and Baseline Visit
• Documented reversibility of 15% within 12 months of Screening or at Screening Visit (15% increase from pre-FEV-1 levels following albuterol inhalation or neubulized albuterol administration)
• Symptoms of asthma during Run-in
• Females of childbearing potential must have a negative urine pregnancy test at Screening and Baseline Visits. Females are eligible only if they are not pregnant or lactating, and are either sterile, or using acceptable methods of contraception.
• Must otherwise be healthy
• Provide written informed consent. Wishes of minors must be respected.

Exclusion Criteria:

Patients will not be eligible for the study if they meet any of the following criteria:

• Life-threatening asthma within the past year or during the Run-In Period.
• History of systemic corticosteroid medication within 3 months before the Screening Visit.
• History of omalizumab use within past 6 months.
• History of leukotriene receptor antagonist use, e.g., montelukast, within past week.
• Current evidence or history of any clinically significant disease or abnormality including uncontrolled hypertension, uncontrolled coronary artery disease, congestive heart failure, myocardial infarction, or cardiac dysrhythmia.
• Upper or lower respiratory infection within 4 weeks prior to Screening Visit or during Run-In Period.
• Significant, non-reversible, pulmonary disease (e.g., chronic obstructive pulmonary disease [COPD], cystic fibrosis, bronchiectasis).
• Known Human Immunodeficiency Virus (HIV)-positive status.
• Smoking history equivalent to "10 pack years".
• Current smoking history within 12 months prior to Screening Visit.
• Current evidence or history of alcohol and/or substance abuse within 12 months prior to Screening Visit.
• Patients who are confined in institution.