Inclusion Criteria:

• Must be ³6 to £65 years of age, of either sex, and of any race, with a diagnosis of asthma at least 2 years prior to the Screening Visit.

• Must have a history of two or more upper respiratory infection-induced asthma exacerbations in the past 24 months.

  • For subjects 6 to 17 years of age, exacerbations for the purpose of the inclusion criteria, will be defined as:
  • An increase of four or more puffs of a short-acting beta-agonist (SABA) per day for at least 3 consecutive days, or
  • An increase of two or more nebulizations of a SABA per day for at least 3 consecutive days, or
  • Documentation of AM peak flow drops >20% per day for at least 2 consecutive days, or
  • Documentation of AM peak flow drops of >=50% for at least 1 day.
• Must have been on a stable dose of any asthma medication (including immunotherapy) for at least 1 month prior to the Screening Visit.
• Must have a pre-bronchodilator FEV1 ³50% predicted at the Screening Visit, when all prohibited medications have been withheld for the specified interval.
• If a reversibility test has not been performed within the previous 24 months, a subject, ³17 years of age, must demonstrate an increase in absolute FEV1 of ³12%, with an absolute volume increase of at least 200 mL. A subject <17 years of age, must demonstrate an increase in absolute FEV1 ³12%.
• Must cohabit with at least one other person (family member, roommate).
• A subject (or the subject’s legal representation) must be willing to give written informed consent and be able to adhere to dose and visit schedules.
• Must be free of any clinically significant disease, other than asthma, which would interfere with study evaluation.
• Must be in general good health, as confirmed by routine clinical and laboratory testing. All laboratory tests (CBC, blood chemistries, and urinalysis) and ECGs must be within normal limits or clinically acceptable to the investigator/sponsor.
• Female of childbearing potential must be using a medically acceptable, adequate form of birth control.

Exclusion Criteria:

• Had an upper or lower respiratory illness or exhibits signs and/or symptoms of a respiratory illness in the 4 weeks prior to the Screening Visit.
• Received any treatment more recently than the indicated washout period prior to Screening or who must continue to receive treatment that is prohibited.
• Smoker or ex-smoker and has smoked within the previous 5 years of Screening or has had a cumulative smoking history >10 pack years.
• Allergy/sensitivity to the study drug or its excipients.
• Female who is breast-feeding, pregnant, or intends to become pregnant.
• Used any investigational drugs within 30 days of Screening.
• Participating in any other clinical study.
• Part of the staff personnel directly involved with this study.
• Family member of the investigational study staff.