Effect of PUR003 on Asthma

Inclusion Criteria: 1. Signed written informed consent. 2. Ability and willingness to return to the outpatient clinic for repeated clinic visits and complete all assessments. 3. Adult male or female subject, 18-60 years of age. 4. Stable, mild asthma not requiring any medical treatment other than short acting inhaled bronchodilators, as needed. 5. No smoking within six months prior to entry 6. Must be medically stable. 7. Female subjects must have a negative pregnancy test 8. Subjects of child bearing potential should be sexually inactive (abstinent) for 14 days prior to the first dose of study medication or using an acceptable form of birth control methods. Exclusion Criteria: 1. History or presence of significant co-existing chronic diseases. 2. History of asthma exacerbations or upper or lower respiratory illness (viral respiratory syndrome, bronchitis, pneumonia) within four weeks of first visit. 3. Pregnancy, breastfeeding. 4. Abused alcohol or illicit drugs that required treatment. 5. Participated in any other investigational drug evaluation within last 30 days. 6. Scheduled to have elective or invasive medical intervention, procedure, or surgery within 6 months.