This study is seeking participants age 6 to less than 12 years who have:
The purpose of this study is to learn about the safety and effects of the study medicine (called ritlecitinib) for the possible treatment of severe alopecia areata. Alopecia areata is a condition that causes hair loss.
All participants in this study will receive either study medicine (ritlecitinib) or placebo. A placebo does not have any medicine in it but looks just like the medicine being studied.
One-third of participants will receive ritlecitinib higher dose, one-third participants will receive ritlecitinib lower dose, and one-third participants will receive placebo.
The study medicine is a capsule that is taken by mouth. It is taken once each day at home.
The study will compare the experiences of participants receiving ritlecitinib to participants receiving placebo. This will help see if ritlecitinib is safe and effective.
Participants will take part in this study for 6 months. During this time, they will have 8 study visits at the study clinic. The study team will also call participants about 8 times over the phone.
For more information, visit the Pfizer Clinical Trials site.