Study to Assess the Efficacy and Safety of Budesonide (PT008) 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)