This study looks at how well a combination of medicines, **Fluticasone Furoate (FF)**, **Umeclidinium (UMEC)**, and **Vilanterol (VI)**, helps kids aged 12-17 with asthma. Asthma is a condition that makes it hard to breathe. The study compares this combination to just **FF/VI**. The goal is to see if the combination improves lung function after 24 weeks of treatment.

To join, participants must be 12-17 years old and have had asthma for at least a year. They should be using inhaled medicines every day for at least 12 weeks before starting. However, those who have had serious asthma attacks recently or other lung problems can't join.

• The study lasts around 6 months.
• Participants may need regular check-ins with doctors.
• There could be risks from the new medicine combination.

This study could help find better ways to treat asthma in teenagers. Participants might receive medical exams and asthma care during the study. It's important to talk to a doctor to see if joining is a good idea.