Mild asthma

This is a pharmacodynamic bioequivalence bronchoprovocation study using single-dose, double-blind, double-dummy, randomized, study consisting of four study treatments (zero dose [Placebo], E.Q. 90 mcg Base dose of R inhalation aerosol, E.Q. 180 mcg Base dose of R inhalation aerosol, E.Q. 90 mcg Base dose of T inhalation aerosol) and four Periods (Period 1 to Period 4). Randomization procedure at Period 1 will assign any one study treatment to be administered in each Period in a cross-over manner. By the end of Period 4, a subject who completes dosing in all four Periods would have administered all four treatments in the study.
The efficacy variable, post-dose PC20 obtained during each Period is the provocative concentration of the methacholine challenge agent required to reduce the FEV1 by 20% following administration of differing doses of albuterol (or placebo) by inhalation. The 20% reduction in FEV1 is determined as compared to post-saline FEV1 measured before the Placebo or Albuterol administration.
The pharmacodynamic equivalence will be based on the dose-scale method of analysis of the post-dose PC20 If the 90% confidence interval for the relative bioavailability (F) falls within 67.00% -150.00% then it will be considered that pharmacodynamic equivalence is established.

The purpose of this study is to compare the efficacy and safety of albuterol/budesonide to albuterol in changes in airway inflammation, asthma symptoms, and rescue therapy utilization in adults with mild asthma.
Study details include:
* The study duration will be up to 15 weeks.
* The treatment duration will be 12 weeks.
* The visit frequency will be once every 4 weeks, with 3 clinic visits and 2 video calls in total.

This study will measure lung function tests and examine biological samples collected before and after inhaled allergen challenges and diluent (control) challenges in participants with mild allergic asthma.