Study to assess the efficacy and safety of four doses of budesonide inhalation aerosol (BD MDI, PT008) relative to placebo MDI in adult subjects with mild to moderate persistent asthma.

This is a randomized, double-blind, chronic dosing (4 weeks), four-period, five-treatment, incomplete block, cross-over, multicenter study to assess the efficacy and safety of four doses of budesonide inhalation aerosol (BD MDI, PT008) relative to placebo MDI in adult subjects with mild to moderate persistent asthma.

Inclusion Criteria:

• ≥ 18 - 65 years of age
• Diagnosis of mild to moderate persistent asthma, diagnosed at least 6 months prior to screening
• Currently receiving treatment with a low to medium dose of an inhaled corticosteroid (ICS) OR a combination of controller medications for at least 4 weeks preceding screening
• Pre-albuterol FEV1 of > 60% and < 85% of predicted normal value
• Reversibility: Increase in FEV1 of ≥ 12% and ≥ 200 mL over the pre-albuterol FEV1 within 30 - 60 minutes after the inhalation of 4 puffs of Ventolin hydrofluoroalkane (HFA)
• Asthma Symptom Criteria: Have required albuterol use on at least two of the last seven days and have an Asthma Control Questionnaire (ACQ) total score ≥ 1.5 prior to Randomization

Exclusion Criteria:

• Life-Threatening Asthma: A subject must not have life-threatening asthma defined as a history of significant asthma episode(s) requiring intubation associated with hypercapnia, respiratory arrest, hypoxic seizures, or asthma-related syncopal episode(s) within the 12 months prior to screening
• Worsening of Asthma: A subject must not have experienced a worsening of asthma which involved an emergency department visit, hospitalization or use of oral/parenteral corticosteroids within 6 weeks of screening
• Intermittent, Seasonal, or Exercise-Induced Asthma Alone: Subjects with only intermittent, seasonal or exercise-induced asthma are excluded from participation in this study
• Concurrent Respiratory Disease
• Pregnant women or nursing mothers
• A current diagnosis of Chronic Obstructive Pulmonary Disease (COPD
• Current smokers or subjects with a > 10 pack year history of cigarettes, cigars, or pipe smoking
• Respiratory tract infection within 6 weeks prior to Visit 1
• Subjects with documented myocardial infarction within a year from screening visit
• Clinically significant abnormal ECG
• Abnormal liver function tests defined as aspartate aminotransferase (AST), alanine aminotransferace (ALT), alkaline phosphatase or total bilirubin ≥ 1.5 times upper limit of normal on repeat testing
• Subjects who have cancer that has not been in complete remission for at least 5 years
• Drug Allergy: Subjects who have a history of hypersensitivity to any component of the metered-dose inhaler (MDI)

Double Blind