Evaluation of Efficacy and Safety for Single Dose of E004 in Children With Asthma

This is a randomized, double-blinded, placebo-controlled, crossover, single dose study to be conducted in pediatric patients (4 - 11 years) with asthma. The main features of the study design are: The entire study consists of a Screening Visit, and a Study Period consisting of two (2) crossover Study Visits separated by a 2 to 14-day interval. All study subjects must be properly consented, under adult supervision, and screened against the inclusion and exclusion criteria at the Screening Visit and confirmed for enrollment on Visit 1. Efficacy and safety evaluations of E004 are conducted at each Study Visit. This study employs two (2) double-blinded treatment arms as outlined in Table 2. A double-blinded design will be applied to E004 (Arm T) and Placebo-HFA (Arm P) since they are identical in all physical attributes and share a comparable formulation. The enrolled subjects will be randomized into two sequences (as follows) to participate in two (2) crossover Study Visits with a 2 - 14 day interval between visits. Randomization is achieved using a ratio of 1:1. Use E004 (T) and Placebo (P) in Visits 1 and 2, respectively or use Placebo (P) and E004 (T) in Visits 1 and 2, respectively Subjects will be trained at the screening visit and each Study Visit for the correct dosing and spirometry methods. Under the supervision of dosing monitor, subjects will self-administer two (2) inhalations of the randomized study treatment, with a \~1 min interval at each Study Visit. For the Screening and Study Visits, the subjects will be required to be at the site for a 30 minute "resting period". This resting period is designed to maintain a stable and consistent physical status of the subjects prior to the start of the baseline FEV1 procedures. For the Screening Visit, this period will begin upon subject arrival. For the Study Visits, the period will begin at the end of the option breakfast (or upon arrival if the breakfast is declined). For each Study Visit, subjects will need to arrive at the study site early enough to complete all necessary baseline evaluations. The study site will provide an optional breakfast but it must be eaten at least 30 minutes prior to the pre-dose baseline FEV1 measurements. The optional breakfast will be light, and contain no added sugar. If the subjects decline the breakfast (i.e. they have already eaten a light breakfast prior to arriving), they are required to remain at the site for at least 30 minutes prior to the start of the Baseline FEV1 measurements, in order to maintain a stable physical status. Baseline vital signs and safety evaluations will be taken prior to the pre-dose baseline FEV1 measurement. These can be performed during the 30 minute "resting period". Efficacy of the treatments at each visit will be evaluated based on spirometric measurements of serial FEV1 determined at the Pre-dose Baseline, and the seven (7) serial Post-dose FEV1 responses at 5, 30, 60, 120, 150, 180) and 240 minutes. This study will be conducted with a double-blinded technique. This means neither the subject nor the site staff will be aware of the identity of the treatment arm since both study treatments are in identical looking containers.