**A Study to Assess the Effect of Dexpramipexole in Adolescents and Adults With Eosinophilic Asthma** This study is testing a new medicine called dexpramipexole to help people with eosinophilic asthma. Eosinophilic asthma is a type of asthma where the body has too many special white blood cells called eosinophils, making breathing hard. Dexpramipexole is being added to the usual asthma treatments to see if it improves lung function, asthma control, and overall quality of life. It will also check if the medicine is safe and if people can tolerate it well. **Key Points:** - **Participation:** Teens and adults (12+ years) with asthma who are already taking specific asthma medicines can join. - **Study Duration:** Participants will be involved in the study for several visits, starting with a screening to see if they qualify and continuing with regular check-ins. - **Safety Measures:** Women of childbearing age must use birth control. Participants must not have certain health conditions or be using specific medications. Participants might be compensated for their time and travel. It's important to discuss with doctors before joining to understand all risks and benefits.