Period 1: Participants receive matching placebo to upadacitinib orally once a day for 24 weeks then upadacitinib 30 mg once daily for 32 weeks, and matching placebo to adalimumab by subcutaneous injection EOW for the entire 56 weeks.

Period 2: Participants will continue to receive upadacitinib 30 mg once daily.

Oral tablet

Oral tablet

Administered by subcutaneous injection

The sIGA is a 5 point scale ranging from 0 to 4, based on the investigator's assessment of the average elevation, erythema, and scaling of all psoriatic lesions at the current visit. A lower score indicates less severe psoriasis (0 = clear, 1 = almost clear, 2 = mild, 3 = moderate and 4 = severe).

PASI is a composite score based on the percentage of the body surface area (BSA) affected by psoriasis and the intensity of erythema (reddening), induration (thickening or hardening of the skin), and desquamation (peeling of the skin) of lesions assessed at 4 anatomic sites (head, upper extremities, trunk, and lower extremities). At each location, the percentage of BSA involvement is assigned a score from 0 (no involvement) to 6 (90% to 100% involvement), and erythema, induration, and desquamation are scored on a scale from 0 (no symptoms) to 4 (very marked).

The PASI score ranges from 0 (no psoriasis) to 72 (very severe psoriasis). A PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from Baseline in PASI score, and was assessed in participants with Baseline psoriasis BSA involvement ≥ 3%.

The Sharp-van der Heijde modified scoring method for PsA measures the level of joint damage from radiographs of the hands and feet, and was assessed by 2 independent, blinded readers.

Joint erosion severity was assessed in 20 joints in each hand and wrist and 6 joints in each foot. Each joint was scored from 0 (no erosion) to 5 for hands/wrists or to 10 for feet (complete collapse). The total erosion score ranges from 0 to 320 (worst).

Joint space narrowing (JSN) was assessed in 20 joints of each hand and wrist, and 6 joints of each foot, from 0 (normal) to 4 (complete loss of joint space, bony ankylosis, or luxation). The total JSN score ranges from 0 to 208 (worst).

Joints with gross osteolysis or pencil in cup were assigned the maximum score for both erosions and JSN.

The total mTSS score is the sum of the joint erosion and JSN scores and ranges from 0 (normal) to 528 (worst). A negative change from Baseline indicates improvement in joint damage.

A participant was classified as achieving MDA if 5 of the following 7 criteria were met:

• Tender joint count (out of 68 joints) ≤ 1
• Swollen joint count (out of 66 joints) ≤ 1
• PASI score ≤ 1 (score ranges from 0 - 72) or percent BSA involved with psoriasis ≤ 3%
• Patient's assessment of pain ≤ 1.5 (NRS from 0 to 10)
• Patient's Global Assessment of disease activity ≤ 2 (NRS from 0 to 10)
• HAQ-DI score ≤ 0.5 (index score ranges from 0 to 3)
• Leeds Enthesitis Index ≤ 1 (assesses the presence or absence of enthesitis at 3 bilateral sites, with an overall score range from 0 to 6)

Resolution of enthesitis is defined as a Leeds Enthesitis Index (LEI) score = 0.

LEI is an enthesitis measure developed specifically for PsA and assesses the presence or absence of tenderness at the following 3 bilateral enthesial sites: medial femoral condyles, lateral epicondyles of the humerus, and Achilles tendon insertions. Tenderness on examination is recorded as either present (coded as 1), absent (coded as 0), or not assessed for each of the 6 sites. The LEI is calculated by taking the sum of the scores from the 6 sites. The LEI ranges from 0 to 6 (worst).

Participants who met the following 3 conditions for improvement from Baseline were classified as meeting the ACR20 response criteria:

1. ≥ 20% improvement in 68-tender joint count;

2. ≥ 20% improvement in 66-swollen joint count; and

3. ≥ 20% improvement in at least 3 of the 5 following parameters:

   • Physician global assessment of disease activity
   • Patient global assessment of disease activity
   • Patient assessment of pain
   • Health Assessment Questionnaire - Disability Index (HAQ-DI)
   • High-sensitivity C-reactive protein (hsCRP).

The Short Form 36-Item Health Survey (SF-36) Version 2 is a self-administered questionnaire that measures the impact of disease on overall quality of life during the past 4 weeks. The SF-36 consists of 36 questions in eight domains (physical function, pain, general and mental health, vitality, social function, physical and emotional health).

The physical component score is a weighted combination of the 8 subscales with positive weighting for physical functioning, role-physical, bodily pain, and general health. The PCS was calculated using norm-based scoring so that 50 is the average score and the standard deviation equals 10. Higher scores are associated with better functioning/quality of life; a positive change from Baseline score indicates an improvement.

The FACIT-Fatigue questionnaire is a self-administered patient questionnaire that consists of 13 questions designed to measure the degree of fatigue experienced by participants in the previous 7 days, including physical fatigue (e.g., I feel tired), functional fatigue (e.g., trouble finishing things), emotional fatigue (e.g., frustration), and social consequences of fatigue (e.g., limits social activity). Participants respond to the questions on a scale from 0 'not at all' to 4 'very much'. The FACIT Fatigue score is computed by summing the item scores, after reversing those items that are worded in the negative direction. The FACIT-Fatigue subscale score ranges from 0 to 52, where higher scores represent less fatigue. A positive change from Baseline indicates improvement.

Participants who met the following 3 conditions for improvement from Baseline were classified as meeting the ACR20 response criteria:

1. ≥ 20% improvement in 68-tender joint count;

2. ≥ 20% improvement in 66-swollen joint count; and

3. ≥ 20% improvement in at least 3 of the 5 following parameters:

   • Physician global assessment of disease activity
   • Patient global assessment of disease activity
   • Patient assessment of pain
   • Health Assessment Questionnaire - Disability Index (HAQ-DI)
   • High-sensitivity C-reactive protein (hsCRP).

Resolution of dactylitis is defined as a Leeds Dactylitis Index (LDI) score = 0.

The Leeds Dactylitis Index (LDI) is a score based on finger circumference and tenderness, assessed and summed across all dactylitic digits (fingers and toes). The presence of a dactylitic digit is defined as at least one affected AND tender digit with circumference increase over reference digit ≥ 10%. The reference digit circumference is either the contralateral digit (unaffected digit on opposite hand or foot) if available, or from a standard reference table if otherwise. Tenderness of affected digits is assessed on a scale from 0 [none] to 3 [worst].

The ratio of circumference between an affected digit and reference digit is multiplied by the tenderness score for each affected digit. The results from each involved digit are summed to provide the final LDI. A higher LDI indicates worse dactylitis.

Participants were asked to indicate the severity of their arthritis pain within the previous week on a numerical rating scale (NRS) from 0 to 10. A score of 0 indicates "no pain" and a score of 10 indicates "worst possible pain." A negative change from Baseline indicates improvement.

The Health Assessment Questionnaire - Disability Index is a patient-reported questionnaire that measures the degree of difficulty a person has in accomplishing tasks in 8 functional areas (dressing, arising, eating, walking, hygiene, reaching, gripping, and errands and chores) over the past week. Participants assessed their ability to do each task on a scale from 0 (without any difficulty) to 3 (unable to do). Scores were averaged to provide an overall score ranging from 0 to 3, where 0 represents no disability and 3 represents very severe, high-dependency disability.

A negative change from Baseline in the overall score indicates improvement.

The SAPS is an 11-item self-assessment of psoriasis symptoms that includes questions on: pain, itching, redness, scaling, flaking, bleeding, burning, stinging, tenderness, pain due to skin cracking, and joint pain. Each item is scored from 0 to 10, with 0 being least severe and 10 being most severe. The total score is generated by summing the 11 items and ranges from 0 to 110 (worst). A negative change from Baseline in the total score indicates improvement.

Participants who met the following 3 conditions for improvement from Baseline were classified as meeting the ACR50 response criteria:

1. ≥ 50% improvement in 68-tender joint count;

2. ≥ 50% improvement in 66-swollen joint count; and

3. ≥ 50% improvement in at least 3 of the 5 following parameters:

   • Physician global assessment of disease activity
   • Patient global assessment of disease activity
   • Patient assessment of pain
   • Health Assessment Questionnaire - Disability Index (HAQ-DI)
   • High-sensitivity C-reactive protein (hsCRP).

Participants who met the following 3 conditions for improvement from baseline were classified as meeting the ACR70 response criteria:

1. ≥ 70% improvement in 68-tender joint count;

2. ≥ 70% improvement in 66-swollen joint count; and

3. ≥ 70% improvement in at least 3 of the 5 following parameters:

   • Physician global assessment of disease activity
   • Patient global assessment of disease activity
   • Patient assessment of pain
   • Health Assessment Questionnaire - Disability Index (HAQ-DI)
   • High-sensitivity C-reactive protein (hsCRP).

Participants who met the following 3 conditions for improvement from baseline were classified as meeting the ACR20 response criteria:

1. ≥ 20% improvement in 68-tender joint count;

2. ≥ 20% improvement in 66-swollen joint count; and

3. ≥ 20% improvement in at least 3 of the 5 following parameters:

   • Physician global assessment of disease activity
   • Patient global assessment of disease activity
   • Patient assessment of pain
   • Health Assessment Questionnaire - Disability Index (HAQ-DI)
   • High-sensitivity C-reactive protein (hsCRP).

Participants randomized to receive adalimumab 40 mg by subcutaneous injection EOW and matching placebo to upadacitinib orally QD for 56 weeks.

Participants randomized to receive upadacitinib 15 mg orally QD and matching placebo to adalimumab by subcutaneous injection EOW for 56 weeks.

Participants randomized to receive upadacitinib 30 mg orally QD and matching placebo to adalimumab by subcutaneous injection EOW for 56 weeks.

Participants randomized to receive matching placebo to upadacitinib orally once a day (QD) for 24 weeks followed by upadacitinib 15 mg orally once a day (QD) for 32 weeks (Weeks 24 to 56), as well as matching placebo to adalimumab administered by subcutaneous injection every other week (EOW) from Weeks 1 to 56 in Period 1. During Period 2 (Weeks 56 to 260) participants continued to receive upadacitinib 15 mg orally once a day (QD).

Participants randomized to receive matching placebo to upadacitinib orally once a day (QD) for 24 weeks followed by upadacitinib 30 mg orally once a day (QD) for 32 weeks (Weeks 24 to 56), as well as matching placebo to adalimumab administered by subcutaneous injection every other week (EOW) from Weeks 1 to 56 in Period 1. During Period 2 (Weeks 56 to 260) participants continued to receive upadacitinib 30 mg orally once a day (QD).

Participants randomized to receive adalimumab 40 mg by subcutaneous injection every other week (EOW) and matching placebo to upadacitinib orally once a day (QD) for 56 weeks in Period 1 who continued to receive 40 mg adalimumab EOW in Period 2 (Weeks 56 to 260).

Participants randomized to receive upadacitinib 15 mg orally once a day (QD) and matching placebo to adalimumab by subcutaneous injection EOW for 56 weeks in Period 1 who continued to receive 15 mg upadacitinib QD in Period 2 (Weeks 56 to 260).

Participants randomized to receive upadacitinib 30 mg orally once a day (QD) and matching placebo to adalimumab by subcutaneous injection every other week (EOW) for 56 weeks in Period 1 who continued to receive 30 mg upadacitinib QD in Period 2 (Weeks 56 to 260).

Completed Week 56 (Period 1)