Alopecia areata (AA) is a disease that happens when the immune system attacks hair follicles and causes hair loss. AA usually affects the head and face, but hair loss can happen on any part of the body. The purpose of this study is to assess how safe, effective, and tolerable upadacitinib is in adolescent and adult participants in Japan with severe AA.

Upadacitinib is an approved drug being investigated for the treatment of AA. In Period A, participants are placed in 1 of 3 groups, called treatment arms. Each group receives a different treatment. There is a 1 in 3 chance that participants will be assigned to placebo. In Period B, participants originally randomized to a upadacitinib dose group in Period A will continue their same treatment in Period B. Participants originally randomized to Placebo in Period A will be re-randomized in 1 of 2 groups receiving upadacitinib. Participants who complete Period B can join Period C and will receive 1 of 2 doses of upadacitinib for up to 52 weeks based on their SALT score. Around 123 adolescent and adult participants with severe AA will be enrolled in the study at approximately 20 sites in Japan.

Participants will receive oral tablets of either upadacitinib or placebo once daily for up to 104 weeks with the potential of being re-randomized into a different treatment group at Weeks 24 and 52. Participants will be followed up for up to 30 days after their last study drug dose.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.

Inclusion Criteria:

• Participant is judged to be in good health as determined by the Principal Investigator, based upon the results of the Screening assessments and medical history.
• Diagnosis of severe alopecia areata (AA) with Severity of Alopecia Tool (SALT) score >= 25 (>= 25% scalp hair loss) at Screening and Baseline.
• Current episode of AA of less than 8 years.

Exclusion Criteria:

• Current diagnosis of primarily diffuse type of AA.
• Current diagnosis of other types of alopecia that would interfere with evaluation of AA, including but not limited to female pattern hair loss, male pattern hair loss (androgenetic alopecia) Stage III or greater based on Hamilton-Norwood classification, traction alopecia, lichen planopilaris (LPP), discoid lupus, frontal fibrosing alopecia (FFA), central centrifugal cicatricial alopecia (CCCA), folliculitis decalvans, trichotillomania, and telogen effluvium.
• Diagnosis of other types of inflammatory scalp, eyebrow, or eyelash disorders that would interfere with evaluation of AA as determined by the investigator, including but not limited to seborrheic dermatitis, scalp psoriasis, atopic dermatitis (AD), and tinea capitis.
• Active infection(s) requiring treatment with intravenous anti-infectives within 30 days, or oral/intramuscular anti-infectives within 14 days prior to the Baseline Visit.
• Chronic recurring infection and/or active viral infection that, based on the investigator's clinical assessment, makes the participant an unsuitable candidate for the study.

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To learn more about the process, or to submit a request, visit the following link https://www.abbvieclinicaltrials.com/hcp/data-sharing/