Patient description: A 39-year-old man came to the clinic with cough and shortness of breath that was not relieved by his inhaler. He had these symptoms for 5 days during the past 2 weeks. He doubled his oral corticosteroids in the past week. He is a chef with a history of asthma for 3 years, suffering from frequent cough, wheezing, and shortness of breath and chest tightness. The symptoms become more bothersome within 1-2 hours of starting work every day and worsen throughout the work week. His symptoms improve within 1-2 hours outside the workplace. Spirometry was performed revealing a forced expiratory volume in the first second (FEV1) of 63% of the predicted. His past medical history is significant for seasonal allergic rhinitis in the summer. He doesn't smoke or use illicit drugs. His family history is significant for asthma in his father and sister. He currently uses inhaled corticosteroid (ICS) and fluticasone 500 mcg/salmeterol 50 mcg, one puff twice daily.

Clinical trial eligibility criteria: eligible ages (years): 12.0-999.0,  Asthma Willingness to participate and comply with procedures by signing a written informed consent years of age or older of either gender and any race Women of childbearing potential (includes women who are less than 1 year postmenopausal and currently are or will become sexually active during the study) must be using or agree to use an acceptable method of birth control unless they are surgically sterilized Must understand and be able to adhere to dosing and visit schedules, and agree to record symptom severity scores, PEFR values, medication times, and concomitant medications accurately and consistently in a daily diary Diagnosed history of mild-moderate persistent asthma for at least 12 months FEV1 must be >60% of predicted normal or personal best FEV1 during the last 12 months Using daily inhaled corticosteroids for at least 30 days prior to Screening. In the Screening Visit patients FEV1 should be >= 65% to <= 90% predicted Asthma Symptom Total daily (AM+PM) severity score at Screening Visit should be <= 2 For two weeks prior to Screening, subjects must have been on a stable regimen of one of the following twice daily regimen: fluticasone propionate (FP) >= 100 <= 500 mcg/day; budesonide (BUD) >= 200  Females who are pregnant or breast-feeding Subjects who have not observed the designated washout periods for any of the prohibited medications Subjects who have used any investigational product within 30 days or any antibodies for asthma or allergic rhinitis in the past 90 days prior to enrollment Subjects who have any clinically significant deviation from normal in the physical examination that may interfere with the study evaluations or affect subject safety Subjects who have required systemic steroids within the previous month Subjects who are allergic or have an idiosyncratic reaction to corticosteroids Subjects who have required inpatient hospitalization for asthma control within the previous 3 months, or more than once in the previous 6 months Subjects with clinical evidence of chronic obstructive pulmonary disease or lung diseases other than asthma Subjects who have experienced an upper or lower respiratory tract infection within the previous 2 weeks prior to the Screening Visit Subjects with evidence of clinically significant oropharyngeal candidiasis