A Study of LY4005130 in Adult Participants With Severe Alopecia Areata (Hair Loss)

This study is looking for adults aged between 18 and 50 years old. To join, you must have severe alopecia areata, meaning you've lost hair on at least half, but not more than 90%, of your scalp. Your current hair loss episode must have lasted for at least 6 months but no longer than 4 years, and your hair shouldn't have grown back much on its own in the last six months.

You cannot join this study if you have a different type of hair loss, or if you are currently using other alopecia areata treatments or planning to use them during the study. It's also not suitable for you if you've had certain other treatments in the past, like specific 'JAK inhibitors' medicines, or if you've had major surgery recently or need one soon.

Also, if you have other serious health conditions that need frequent hospital visits or strong medicines, or specific heart, lung, stomach, or other disorders, this study might not be safe for you. The study team will review your full medical history to make sure it's safe for you to take part.

If you decide to take part in this study, the study medicine, LY4005130, will be given to you directly into a vein in your arm (this is called an intravenous or IV infusion). You will receive either the active medicine or a placebo (a dummy medicine) – you won't know which one you are getting. During the study, you will have several appointments at the study clinic. These visits will involve various checks, such as measuring your hair loss, physical examinations, and taking blood samples. These blood tests help us understand how the medicine is working and how your body is reacting to it. The entire study, including the initial checks to see if you can join, will last for about 48 weeks, which is nearly a year.