A Study of Ixekizumab (LY2439821) in Children With Juvenile Idiopathic Arthritis Categories of Enthesitis-related Arthritis (Including Juvenile Onset Ankylosing Spondylitis) and Juvenile Psoriatic Arthritis

Percentage of Participants Achieving JIA ACR 30 (Adalimumab - OLT Period)

JIA ACR, is comprised of 6 variables: number of active joints, number of joints with limited range of motion, Physician's Global Assessment of Disease Activity, Parent's Global Assessment of Well-Being, physical function (measured by the Childhood Health Assessment Questionnaire \[CHAQ\]), and acute-phase reactants (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]). A JIA ACR30 response is defined as at least 30% improvement from baseline in at least 3 of any 6 variables in the core set, with no more than 1 of the remaining variables worsening by more than 30%.

Time frame: Week 16

Percentage of Participants Achieving JIA ACR 50/70/90/100 (OLT Period)

JIA ACR, is comprised of 6 core set variables: number of active joints, number of joints with limited range of motion, Physician's Global Assessment of Disease Activity, Parent's Global Assessment of Well-Being, physical function (measured by the Childhood Health Assessment Questionnaire \[CHAQ\]), and acute-phase reactants (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]). A JIA ACR 50/70/90 response is defined as a greater than or equal to (≥) 50/70/90/100% improvement from baseline in at least 3 of any 6 variables in the core set, with no more than 1 of the remaining variables worsening by more than 30%.

Time frame: Week 16

Percentage of Participants Achieving JIA ACR 30/50/70/90/100 (OLE Period)

JIA ACR, is comprised of 6 core set variables: number of active joints, number of joints with limited range of motion, Physician's Global Assessment of Disease Activity, Parent's Global Assessment of Well-Being, physical function (measured by the Childhood Health Assessment Questionnaire \[CHAQ\]), and acute-phase reactants (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]). A JIA ACR 30/50/70/90 response is defined as a greater than or equal to (≥) 30/50/70/90/100% improvement from baseline in at least 3 of any 6 variables in the core set, with no more than 1 of the remaining variables worsening by more than 30%.

Time frame: Week 104

Change From Baseline in Psoriasis Area and Severity Index (PASI) for Juvenile Psoriatic Arthritis (JPsA) Participants With at Least 3% Body Surface Area (BSA) at Baseline (OLT Period)

The PASI is an index that combines assessments of the extent of body-surface involvement in 4 anatomical regions (head, trunk, arms, and legs) and the severity of scaling (S), redness (R), and plaque induration/infiltration thickness (T) in each region, yielding an overall score of 0 for no psoriasis to 72 for the most severe disease. Severity is rated for each index (R, S, T) on a 0 to 4 scale (0 for no involvement up to 4 for severe involvement): 0 = none 1. = slight 2. = moderate 3. = severe 4. = very severe The various body regions are weighted to reflect their respective proportion of BSA.

Time frame: Baseline, Week 16

Change From Baseline in Psoriasis Area and Severity Index (PASI) for Juvenile Psoriatic Arthritis (JPsA) Participants With at Least 3% Body Surface Area (BSA) at Baseline (OLE Period)

The PASI is an index that combines assessments of the extent of body-surface involvement in 4 anatomical regions (head, trunk, arms, and legs) and the severity of scaling (S), redness (R), and plaque induration/infiltration thickness (T) in each region, yielding an overall score of 0 for no psoriasis to 72 for the most severe disease. Severity is rated for each index (R, S, T) on a 0 to 4 scale (0 for no involvement up to 4 for severe involvement): 0 = none 1. = slight 2. = moderate 3. = severe 4. = very severe The various body regions are weighted to reflect their respective proportion of BSA.

Time frame: Baseline, Week 104

Change From Baseline in Leeds Enthesitis Index (LEI) for Participants With Enthesitis Related Arthritis (ERA) at Baseline (OLT Period)

The LEI was developed specifically for use in psoriatic arthritis (PsA). It measures enthesitis at 6 sites (lateral epicondyle of humerus, right/left (R/L); medial femoral condyle, (R/L); Achilles tendon insertion, (R/L)). Each site is assigned a score of 0 (absent) or 1 (present); the results from each site are then added to produce a total score (range 0 to 6) with the higher scores indicating more severe enthesitis.

Time frame: Baseline, Week 16

Change From Baseline in Leeds Enthesitis Index (LEI) for Participants With Enthesitis Related Arthritis (ERA) at Baseline (OLE Period)

The LEI was developed specifically for use in psoriatic arthritis (PsA). It measures enthesitis at 6 sites (lateral epicondyle of humerus, right/left (R/L); medial femoral condyle, (R/L); Achilles tendon insertion, (R/L)). Each site is assigned a score of 0 (absent) or 1 (present); the results from each site are then added to produce a total score (range 0 to 6) with the higher scores indicating more severe enthesitis.

Time frame: Baseline, Week 104

Percentage of Participants With Disease Flare (OLT Period)

Disease flare is defined as worsening of ≥30% from baseline in at least 3 of the 6 JIA ACR core set criteria and an improvement of ≥30% in no more than one of the criteria. The JIA ACR, is comprised of 6 core set variables: number of active joints, number of joints with limited range of motion, Physician's Global Assessment of Disease Activity, Parent's Global Assessment of Well-Being, physical function (measured by the Childhood Health Assessment Questionnaire \[CHAQ\]), and acute-phase reactants (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]).

Time frame: Week 2 through Week 16

Percentage of Participants With Disease Flare (OLE Period)

Disease flare is defined as worsening of ≥30% from baseline in at least 3 of the 6 JIA ACR core set criteria and an improvement of ≥30% in no more than one of the criteria. The JIA ACR, is comprised of 6 core set variables: number of active joints, number of joints with limited range of motion, Physician's Global Assessment of Disease Activity, Parent's Global Assessment of Well-Being, physical function (measured by the Childhood Health Assessment Questionnaire \[CHAQ\]), and acute-phase reactants (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]).

Time frame: Baseline through Week 104

Pharmacokinetics (PK): Trough Concentrations (C-trough) of Ixekizumab (Ixekizumab - OLT Period)

C-trough were measured at specified time points to assess the minimum concentration of ixekizumab in the blood before the next dose was administered.

Time frame: Week 4, 12 and 16 : Pre-dose

Pharmacokinetics (PK): Trough Concentrations (C-trough) of Ixekizumab (Ixekizumab - OLE Period)

C-trough were measured at specified time points to assess the minimum concentration of ixekizumab in the blood before the next dose was administered.

Time frame: Week 20, 32, 56, 80 and 104 : Pre-dose

Percentage of Participants With Treatment-emergent Positive Anti-ixekizumab Antibodies (Ixekizumab - OLT Period)

Percentage of participants with treatment-emergent positive anti-ixekizumab antibodies was summarized by treatment group. Percentage was calculated based on the number of evaluable participants and was calculated by number of participants with treatment-emergent positive anti-ixekizumab antibodies / number of evaluable participants \* 100%.

Time frame: Baseline through Week 16

Percentage of Participants With Treatment-emergent Positive Anti-ixekizumab Antibodies (Ixekizumab - OLE Period)

Percentage of participants with treatment-emergent positive anti-ixekizumab antibodies was summarized by treatment group. Percentage was calculated based on the number of evaluable participants and was calculated by number of participants with treatment-emergent positive anti-ixekizumab antibodies / number of evaluable participants \* 100%.

Time frame: Baseline through Week 104