A Study of Baricitinib (LY3009104) in Children From 6 Years to Less Than 18 Years of Age With Alopecia Areata

Percent Change from Baseline in SALT Score

Time frame: Baseline, Week 36

Percentage of Participants Achieving At Least 90% Improvement from Baseline (SALT90)

Time frame: Week 36

Percentage of Participants Achieving an Absolute SALT ≤10

Time frame: Week 36

Percentage of Participants with Patient Reported Outcome (PRO) for Scalp Hair Assessment Score of 0 or 1 Among Participants 12 Years and Older with PRO for Scalp Hair Assessment Score ≥3 at Baseline

Time frame: Week 36

Mean Change from Baseline in SALT Score

Time frame: Baseline, Week 36

Percentage of Participants Achieving At Least 50% Improvement from Baseline (SALT50)

Time frame: Week 36

Percentage of Participants Achieving At Least 75% Improvement from Baseline (SALT75)

Time frame: Week 36

Percentage of Participants Achieving At Least 100% Improvement from Baseline (SALT100)

Time frame: Week 36

Percentage of Participants Achieving Clinician-Reported Outcome (ClinRO) Measure for Eyebrow (EB) Hair Loss 0 or 1 Among Participants with CLinRO Measure for EB Hair Loss ≥2 at Baseline

Time frame: Week 36

Percentage of Participants Achieving ClinRO Measure for Eyelash (EL) Hair Loss 0 or 1 Among Participants with CLinRO Measure for EL Hair Loss ≥2 at Baseline

Time frame: Week 36

Percentage of Participants Achieving PRO Measure for EB 0 or 1 (Among Participants 12 Years or Older with PRO Measure for EB ≥2 at Baseline)

Time frame: Week 36

Percentage of Participants Achieving PRO Measure for EL 0 or 1 (Among Participants 12 Years or Older with PRO Measure for EL ≥2 at Baseline)

Time frame: Week 36

Mean Change from Baseline in Hospital Anxiety Depression Scale (HADS)

The HADS is a participant-rated instrument used to assess both anxiety and depression and is available in a pediatric self-report for participants ≥12 years old. This instrument consists of 14 item questionnaires, each item is rated on a 4-point scale. Scores for each domain (anxiety and depression) can range from 0 to 21, with higher scores indicating greater anxiety or depression.

Time frame: Week 36

Mean Change from Baseline in Patient-Reported Outcome Measurement Information System (PROMIS) Anxiety Score

The PROMIS Anxiety Short Form (8 questions, 8a v2.0) is available in a pediatric self-report (ages 8 to \<18 years) and for parents/caregivers serving as proxy reporters for their children (youth ages ≥5 years). Both pediatric self-report and proxy-report versions assess anxiety "in the past seven days". Response options range from 1 = Never; 2 = Rarely; 3 = Sometimes; 4 = Often; to 5 = Almost always. Total raw scores are converted to T-Scores with higher scores representing greater anxiety.

Time frame: Baseline, Week 36

Mean Change from Baseline in PROMIS Depression Score

The PROMIS Depression Short Form (8a v2.0 and 6a v2.0) is available in a pediatric self-report (ages 8 to \<18 years) and for parents/caregivers serving as proxy reporters for their children (youth ages ≥5 years). Both pediatric self-report and proxy-report versions assess depression "in the past seven days." Response options range from 1 = Never; 2 = Rarely; 3 = Sometimes; 4 = Often; to 5 = Almost always. Total raw scores are converted to T-Scores with higher scores representing greater depression.

Time frame: Baseline, Week 36

Mean Change from Baseline in PROMIS Peer Relationship Score

The PROMIS Peer Relationships Short Form planned to be used in the study measures 2 aspects of social functioning, friendship quality and peer acceptance, and is available in a pediatric self-report (ages 8 to \<18 years) and for parents/caregivers serving as proxy reporters for their children (youth ages 5 to \<8 years).

Time frame: Baseline, Week 36

Mean Change from Baseline in Family Dermatology Life Quality Index (FDLQI)

The FDLQI is a 10-item validated questionnaire designed for adult (\>16 years old) family members of participants. The questionnaire is completed by family members of the AA participants (for example, parents/caregivers) and measures the secondary impact of the participant's skin disease on family QoL. Response categories include "not at all/not relevant," "only a little," "quite a lot," and "very much," with corresponding scores of 0, 1, 2, and 3, respectively, with unanswered ("not relevant") responses scored as 0.

Time frame: Baseline, Week 36

Pharmacokinetics (PK): Maximum Concentration (Cmax)

Time frame: Baseline through Week 36

PK: Area Under the Concentration Curve (AUC)

Time frame: Baseline through Week 36

Change of Immunoglobulin G (IgG) Titers

Time frame: Pre-Vaccination to 4 Weeks and 12 Weeks Post-Vaccination