This study is looking at AZD4604, a new medicine for adults with asthma that isn't controlled well even with regular treatment. Asthma is a condition where your airways get narrow and swollen, making it hard to breathe. In this study, participants will use a dry-powder inhaler to take the medicine twice a day for 12 weeks. The study is double-blind, meaning neither the participants nor the doctors know who is receiving the actual medicine or a placebo (a fake treatment). Participants must be between 18 and 80 years old and have a history of severe asthma attacks. They should also have been on certain asthma medicines for at least 3 months and have specific lung function test results. The study will last for a few months, including screening and treatment periods.

• Study lasts around 3 months, with 12 weeks of treatment.
• Participants need regular visits and tests.
• No compensation mentioned; participation is voluntary.

Before joining, make sure you meet all the eligibility criteria and understand the risks and commitments involved.