A Study of a New Asthma Medicine in Asthmatics Whose Asthma Worsens With Exercise

Inclusion Criteria: * Outpatient male or female 12 to 50 years of age * Females of child-bearing potential must be willing to use birth control or commit to abstinence during the study * Diagnosis of persistent asthma for at least 6 months * Best pre-bronchodilator FEV1 of at least 70%. * Current use of a low- to moderate-dose inhaled corticosteroid * Ability to withhold albuterol 6 hours prior to visits. * Physically able to perform exercise testing on a treadmill when albuterol has been withheld Exclusion Criteria: * Intermittent asthma, seasonal asthma, or exercise-induced asthma only * Symptomatic allergic rhinitis and/or thrush * Abnormal, clinically significant electrocardigraph * Respiratory infection within 4 weeks of first visit leading to asthma medication change or could affect subjects's asthma status or participation * Asthma exacerbation within 12 weeks of first visit * Respiratory diseases or other concurrent disease that would put subject at risk or confound results interpretation * Investigational medicines within 30 days of first visit or less than five half-lives of medication in prior study * Allergy to study drugs or study drug excipients * Concomitant medications that could interact with study medications or affect the course of asthma * Tobacco use within last year and/or a 10 pack-years history * Inability to comply with requirements of the study * Affiliation with investigator's site (example: family member)