Male or female asthmatics, any racial group. Females of childbearing potential must practise two forms of contraception

Non smokers

Mild to moderate asthmatics according to GINA guidelines for at least 12 months.

History of asthma symptoms increasing in response to external allergens.

Testing positive on skin prick test to an allergen associated with the subject's asthma

Safety and Efficacy Study of OC000459 Dosed Twice Daily for 28 Days in Asthmatic Subjects