The study aims to see how well two inhalers work for asthma in kids aged 12 to less than 18. It compares the budesonide/albuterol inhaler (BDA MDI) with the albuterol sulfate inhaler (AS MDI), both used when needed. Asthma is a condition where the airways in the lungs become narrow, making it hard to breathe. This study is for kids who have had a severe asthma attack in the last year.

There are three periods in the study: a screening period lasting 7 to 28 days, a treatment period of 52 weeks, and a safety follow-up period of 7 to 14 days. Participants will be randomly assigned to one of the inhalers and will continue their usual asthma treatment. There's also a special test (pharmacokinetic sub-study) after the main study to see how the medicine moves in the body.

• Study lasts one year with regular check-ups.
• Participants must have had at least one severe asthma attack in the past year.
• Participants will receive free study inhalers.