This study is testing a medicine called erenumab to see if it helps kids and teens who get bad headaches called chronic migraines. Chronic migraines are headaches that happen a lot, usually more than 15 days a month. The study will compare erenumab to a placebo, which is a fake treatment, to check if it really works. Children aged 6 to 12 and teens aged 12 to 18 can join if they have had migraines for over a year.

The study lasts for several months and has different phases. Some participants get erenumab injections, and some get the placebo. The study will track how many headache days they have each month. Participants will need to use an eDiary to record their headaches, which helps researchers understand the medicine's effect.

• The study involves visits over about 24 to 40 weeks, including safety checks.
• Involves taking monthly injections, either erenumab or placebo.
• Participants will be closely monitored for safety and side effects.

To join, a parent or guardian must agree, and the child must not have other severe health issues or certain types of headaches. The study needs 286 participants to learn if erenumab can help reduce migraine days for young people.