Study to Evaluate the Efficacy and Safety of Filgotinib in Participants With Active Psoriatic Arthritis Who Are Naive to Biologic DMARD Therapy

Percentage of Participants Who Achieved Very Low Disease Activity (VLDA) Response at Weeks 4, 8, 12, and 16

VLDA is a measure to indicate disease remission, and is based on a composite score of 7 domains. A participant is considered as having achieved the VLDA if the participant fulfills all the seven criteria: TJC68 ≤1; SJC66 ≤1; PASI score ≤1 for participants with psoriasis covering BSA \<3% \[PASI evaluates the severity and extent of psoriasis. In PASI, body is divided into four parts, head and neck, upper limb, trunk and lower limbs. Each area is assessed for erythema, induration and scaling, each rated on a scale of 0 to 4. The total score ranges from 0 (no disease) to 72 (maximal disease)\]; PGAPI ≤15 \[using VAS on a scale of 0 (no pain) to (serious pain)\]; PGADA ≤20 \[using VAS on a scale of 0 (very well) to 100 (very poor)\]; HAQ-DI score ≤0.5; LEI score ≤1 with participants with enthesitis at baseline.

Time frame: Weeks 4, 8, 12, and 16

Change From Baseline in Disease Activity in Psoriatic Arthritis (DAPSA) at Weeks 2, 4, 8, 12, and 16

DAPSA is calculated by summing the following components: TJC68; SJC66; PGADA \[using VAS on a scale of 0 (very well) to 100 very poor)\]; PGAPI \[using a VAS on a scale of 0 (no pain) to 100 (serious pain)\] and CRP. DAPSA scores 0-4 = remission, 5-14 = low disease activity, 15-28 = moderate disease activity, and \>28 = high disease activity. The DAPSA score has a lower bound of 0 and has no upper bound. A higher DAPSA score indicated more active disease activity. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Physician's Global Assessment of Psoriasis (PhGAP) at Weeks 2, 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the Body Surface Area (BSA) at Baseline

The PhGAP is used to determine the participant's psoriasis lesions overall at a given time point. The participant's psoriasis disease activity is assessed by a physician according to the grades of induration, erythema, and scaling on a scale of 0 to 5. The sum of the three grades is used to obtain the total average score. PhGAP is based on the total average score on a scale of 0-5 where, 0 = cleared, 1 = minimal, 2 = mild, 3 = moderate, 4 = marked, and 5 = severe. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Modified Nail Psoriasis Severity Index (mNAPSI) at Weeks 4, 8, 12, and 16 in Participants With Psoriatic Nail Involvement at Baseline

mNAPSI is used to assess each nail abnormality for each of the participant's nails. Three features or groups of features (pitting, onycholysis together with oil-drop dyschromia, and crumbling) of each fingernail are graded on a scale from 0 (no onycholysis together with oil-drop dyschromia, no pitting, no crumbling) to 3 (\>30 onycholysis together with oil-drop dyschromia, \>50 pitting, \>50% crumbling). Four features (leukonychia, splinter, hemorrhages, hyperkeratosis, and red spots in the lunula) are graded with the score of 1 = present or 0 = absent for each fingernail. Each finger has a score between 0 and 13. The total mNAPSI score is the sum of all abnormalities individual score across all fingers, and the total mNAPSI score ranges from 0 to 130. Lower numbers indicate fewer nail abnormalities. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Change From Baseline in Leeds Enthesitis Index (LEI) at Weeks 4, 8, 12, and 16 in Participants With Enthesitis at Baseline

Enthesitis is assessed using LEI. The enthesitis examination by LEI evaluates the presence or absence of pain by applying local pressure on 6 anatomical sites: medial femoral condyle (left and right), lateral epicondyle (left and right), and the achilles tendon insertion (left and right). Enthesitis at each site is scored as 0 (enthesitis absent) and 1 (enthesitis present). LEI is derived as the sum of the enthesitis score over the 6 sites mentioned above. The total score ranges from 0 to 6, higher scores indicates greater degree of enthesitis. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Change From Baseline in 12-Item Psoriatic Arthritis Impact of Disease (PsAID-12) Score at Weeks 4 and 16

The PsAID questionnaire assesses the impact of PsA on people's lives. The PsAID is calculated based on 12 numerical rating scales (NRS) questions. Each NRS is assessed as a number between 0 and 10. Total score is calculated as the sum of the individual scores, (some of which were multiplied by a weighting factor) divided by 20 for a total possible score of 0 to 10, where higher score indicates worse impact of disease. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, and 16 weeks

Percentage of Participants With PASDAS Low Disease Activity (LDA) at Weeks 4 and 16

PASDAS is a composite disease activity measure for psoriatic arthritis. It includes components of PGADA \[using VAS on a scale of 0=very well to 100=very poor\]; PhGADA \[using VAS on a scale of 0=no disease activity to 100=maximum disease activity\]; 36-item short form survey (SF-36) \[a questionnaire which measures quality of life across eight domains to determine a physical component summary (PCS) with a score range of 0-100, higher scores indicates better health status\]; TJC68; SJC66; leeds enthesitis index(LEI) \[assessed at 6 sites with a score range of 0 to 6, higher scores indicates higher degree of enthesitis\]; Tender dactylitis count (TDC) \[with a score range of 0 to 60, higher score indicates higher degree of dactylitis\]; C-reactive protein (CRP). Total score is calculated as the sum of the individual scores (each score adjusted by weighting factors). The score of PASDAS ranges from 0 to 10, lower scores indicates better function. PASDAS LDA is defined as PASDAS ≤ 3.2.

Time frame: Weeks 4, and 16

Percentage of Participants Who Achieved PASDAS Remission at Weeks 4 and 16

PASDAS is a composite disease activity measure for psoriatic arthritis. It includes components of PGADA \[using VAS on a scale of 0=very well to 100=very poor\]; PhGADA \[using VAS on a scale of 0=no disease activity to 100=maximum disease activity\]; 36-item short form survey (SF-36) \[a questionnaire which measures quality of life across eight domains to determine a physical component summary (PCS) with a score range of 0-100, higher scores indicates better health status\];TJC68;SJC66; leeds enthesitis index(LEI) \[assessed at 6 sites with a score range of 0 to 6, higher scores indicates higher degree of enthesitis\]; Tender dactylitis count (TDC) \[with a score range of 0 to 60, higher score indicates higher degree of dactylitis\]; C-reactive protein (CRP). Total score is calculated as the sum of the individual scores (each score adjusted by weighting factors). The score of PASDAS ranges from 0 to 10, lower scores indicates better function. PASDAS remission is defined as PASDAS ≤ 1.9.

Time frame: Weeks 4, and 16

Percentage of Participants Who Achieved an American College of Rheumatology 20% Improvement Response at Weeks 2, 4, 8, 12, and 16

ACR20 response is achieved when the participant has: ≥ 20% improvement (reduction) from baseline in TJC68, SJC66 and in at least 3 of the following 5 items: PGADA using a VAS on a scale of 0 (very well) to 100 (very poor); PHGADA using a VAS on a scale of 0 (no disease activity) to 100 (maximum disease activity); HAQ-DI inclusive of activities scored on a scale of 0 (no disability) to 3 (completely disabled); HAQ-DI pain assessment using VAS on a scale of 0 (no pain) to 100 (serious pain); and hsCRP. Participants with missing outcomes were set as non-responders.

Time frame: Weeks 2, 4, 8, 12, and 16

Percentage of Participants Who Achieved an American College of Rheumatology 50% Improvement Response at Weeks 2, 4, 8, 12, and 16

ACR50 response is achieved when the participant has: ≥ 50% improvement (reduction) from baseline in TJC68, SJC66 and in at least 3 of the following 5 items: PGADA using a VAS on a scale of 0 (very well) to 100 (very poor); PHGADA using a VAS on a scale of 0 (no disease activity) to 100 (maximum disease activity); HAQ-DI inclusive of activities scored on a scale of 0 (no disability) to 3 (completely disabled); HAQ-DI pain assessment using VAS on a scale of 0 (no pain) to 100 (serious pain); and hsCRP. Participants with missing outcomes were set as non-responders.

Time frame: Weeks 2, 4, 8, 12, and 16

Percentage of Participants Who Achieved an American College of Rheumatology 70% Improvement Response at Weeks 2, 4, 8, 12, and 16

ACR70 response is achieved when the participant has: ≥ 70% improvement (reduction) from baseline in TJC68, SJC66 and in at least 3 of the following 5 items: PGADA using a VAS on a scale of 0 (very well) to 100 (very poor); PHGADA using a VAS on a scale of 0 (no disease activity) to 100 (maximum disease activity); HAQ-DI inclusive of activities scored on a scale of 0 (no disability) to 3 (completely disabled); HAQ-DI pain assessment using VAS on a scale of 0 (no pain) to 100 (serious pain); and hsCRP. Participants with missing outcomes were set as non-responders.

Time frame: Weeks 2, 4, 8, 12, and 16

Change From Baseline in Individual ACR Component: Tender Joint Count Based on 68 Joints (TJC68) at Weeks 2, 4, 8, 12, and 16

TJC68 is an assessment of 68 joints. Each joint is evaluated as 'normal', 'tender', 'tender and swollen', or 'not able to evaluate'. It is derived as the sum of all tender joints. The overall tender joint count ranged from 0 to 68, with a higher score indicating a greater degree of tenderness. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in ACR Component: Swollen Joint Count Based on 66 Joints (SJC66) at Weeks 2, 4, 8, 12, and 16

SJC66 is an assessment of 66 joints. Each joint was evaluated as 'normal', 'swollen', 'tender and swollen', or 'not able to evaluate'. It is derived as the sum of all swollen joints. The overall swollen joint count ranged from 0 to 66, with a higher score indicating a greater degree of swelling. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Individual ACR Component: Patient's Global Assessment of Disease Activity (PGADA) at Weeks 2, 4, 8, 12, and 16

PGADA is assessed by the participants using a VAS on a scale of 0 (very well) to 100 (very poor). A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Individual ACR Component: Physician's Global Assessment of Disease Activity (PhGADA) at Weeks 2, 4, 8, 12, and 16

PhGADA is assessed by the physician using a VAS on a scale of 0 (no disease activity) to 100 (maximum disease activity). A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Individual ACR Component: Health Assessment Questionnaire Disability Index (HAQ-DI)'s Pain Assessment at Weeks 2, 4, 8, 12, and 16

HAQ-DI's pain assessment is done using VAS on a scale of 0 (no pain) to 100 (serious pain). A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Individual ACR Component: High-Sensitivity C-Reactive Protein (hsCRP) at Weeks 2, 4, 8, 12, and 16

The hsCRP is the ACR core set measure of acute phase reactant. It was measured at the central laboratory to help assess the effect of filgotinib on the participant's psoriatic arthritis. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Disease Activity Score 28 (DAS28) C-Reactive Protein (CRP) at Weeks 2, 4, 8, 12, and 16

The DAS28 (CRP) is a measure of the participant's disease activity calculated using the tender joint count (28 joints), swollen joint count (28 joints), PGADA \[using a VAS on a scale of 0 (very well) to 100 (very poor)\] and hsCRP for a total possible score of 1 to 9.4. Higher values indicate higher disease activity. A negative change from baseline indicates improvement.

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Percentage of Participants Who Achieved DAS28(CRP) LDA at Weeks 2, 4, 8, 12, and 16

The DAS28 (CRP) is a measure of the participant's disease activity calculated using the tender joint count (28 joints), swollen joint count (28 joints), PGADA (VAS; 0 = very well to 100 = very poor), and hsCRP for a total possible score of 1 to 9.4. Higher values indicate higher disease activity. DAS28 (CRP) LDA is defined as DAS28(CRP) ≤ 3.2.

Time frame: Weeks 2, 4, 8, 12, and 16

Percentage of Participants Who Achieved DAS28 (CRP) Remission at Weeks 2, 4, 8, 12, and 16

The DAS28 (CRP) is a measure of the participant's disease activity calculated using the tender joint count (28 joints), swollen joint count (28 joints), PGADA (VAS; 0 = very well to 100 = very poor), and hsCRP for a total possible score of 1 to 9.4. Higher values indicate higher disease activity. DAS28 (CRP) remission is defined as DAS28 (CRP) \< 2.6.

Time frame: Weeks 2, 4, 8, 12, and 16

Time to Achieve DAS28 (CRP) LDA

The DAS28 (CRP) is a measure of the participant's disease activity calculated using the TJC (28 joints), SJC (28 joints), PGADA (VAS; 0 = very well to 100 = very poor), and hsCRP for a total possible score of 1 to 9.4. Higher values indicate higher disease activity. DAS28 (CRP) LDA is defined as DAS28 (CRP) ≤ 3.2. Time to achieve DAS28 (CRP) LDA is the number of days from the first dose date of study drug administration to the first time when a participant achieves DAS28 (CRP) LDA.

Time frame: Up to 19 weeks

Percentage of Participants Who Achieved DAPSA LDA at Weeks 2, 4, 8, 12, and 16

DAPSA is calculated by summing the following components: TJC68; SJC66; PGADA \[using VAS on a scale of 0 (very well) to 100 very poor)\]; PGAPI \[using a VAS on a scale of 0 (no pain) to 100 (serious pain)\] and CRP. DAPSA scores 0-4 = remission, 5-14 = low disease activity, 15-28 = moderate disease activity, and \>28 = high disease activity. The DAPSA score has a lower bound of 0 and has no upper bound. A higher DAPSA score indicated more active disease activity. DAPSA LDA is defined as DAPSA ≤ 14.

Time frame: Weeks 2, 4, 8, 12, and 16

Percentage of Participants Who Achieved DAPSA Remission at Weeks 2, 4, 8, 12, and 16

DAPSA is calculated by summing the following components: TJC68; SJC66; PGADA \[using VAS on a scale of 0 (very well) to 100 very poor)\]; PGAPI \[using a VAS on a scale of 0 (no pain) to 100 (serious pain)\] and CRP. DAPSA scores 0-4 = remission, 5-14 = low disease activity, 15-28 = moderate disease activity, and \>28 = high disease activity. The DAPSA score has a lower bound of 0 and has no upper bound. A higher DAPSA score indicated more active disease activity. DAPSA remission is defined as DAPSA ≤ 4.

Time frame: Weeks 2, 4, 8, 12, and 16

Time to Achieve DAPSA LDA

DAPSA is calculated by summing the following components: TJC68; SJC66; PGADA \[using VAS on a scale of 0 (very well) to 100 very poor)\]; PGAPI \[using a VAS on a scale of 0 (no pain) to 100 (serious pain)\] and CRP. DAPSA scores 0-4 = remission, 5-14 = low disease activity, 15-28 = moderate disease activity, and \>28 = high disease activity. The DAPSA score has a lower bound of 0 and has no upper bound. A higher DAPSA score indicated more active disease activity. Time to achieve DAPSA LDA is the number of days from the first dose date of study drug administration to the first time when a participant achieves DAPSA LDA. If the DAPSA LDA is not achieved during main study phase, the time to achieve DAPSA LDA will be censored at the last non-missing DAPSA LDA assessment date during main study phase. If the component scores of DAPSA LDA are at different dates for a visit, the latest date will be used for the derivation of time to achieve DAPSA LDA.

Time frame: Up to 19 weeks

Percentage of Participants Who Achieved Psoriatic Arthritis Response Criteria (PsARC) Response at Weeks 2, 4, 8, 12, and 16

The PsARC response is defined as improvement in at least 2 of the following 4 criteria; ≥ 30% decrease in SJC66, ≥ 30% decrease in TJC68, ≥ 20% decrease in PGADA (VAS; 0 = very well to 100 = very poor), ≥ 20% decrease in PhGADA (VAS; 0 = no disease activity to 100 = maximum disease activity), and with at least one of the 2 joint criteria, with no deterioration in any other criteria.

Time frame: Weeks 2, 4, 8, 12, and 16

Change From Baseline in Psoriasis Area and Severity Index (PASI) at Weeks 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the BSA at Baseline

PASI is assessed in participants with psoriasis covering ≥ 3% of the BSA at Baseline. PASI is a system used for assessing and grading the severity of psoriatic lesions and their response to therapy. In the PASI system, the body is divided into 4 regions: the head and neck, trunk, upper limbs, and lower limbs. Each of these areas are assessed separately for the percentage of the area involved and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4, where 0 = none, 1 = mild, 2 = moderate, 3 = severe and 4 = very severe, which translates to a numeric score that ranges from 0 (indicates no involvement) to 6 (90 percent \[%\] to 100% involvement). The PASI produces a numeric score that can range from 0 (no disease) to 72 (maximal disease). A higher score indicates more severe disease. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Percentage of Participants Who Achieved Psoriasis Area and Severity Index 50% Improvement (PASI50) Response at Weeks 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the BSA at Baseline

PASI is assessed in participants with psoriasis covering ≥ 3% of the BSA at Baseline. PASI is a system used for assessing and grading the severity of psoriatic lesions and their response to therapy. In the PASI system, the body is divided into 4 regions: the head and neck, trunk, upper limbs, and lower limbs. Each of these areas are assessed separately for the percentage of the area involved and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4, which translates to a numeric score that ranges from 0 (indicates no involvement) to 6 (90 percent \[%\] to 100% involvement). The PASI produces a numeric score that can range from 0 (no disease) to 72 (maximal disease). For PASI50, the improvement threshold from baseline in PASI score is 50%. A higher score indicates more severe disease.

Time frame: Weeks 4, 8, 12, and 16

Percentage of Participants Who Achieved Psoriasis Area and Severity Index 75% Improvement (PASI75) Response at Weeks 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the BSA at Baseline

PASI is assessed in participants with psoriasis covering ≥ 3% of the BSA at Baseline. PASI is a system used for assessing and grading the severity of psoriatic lesions and their response to therapy. In the PASI system, the body is divided into 4 regions: the head and neck, trunk, upper limbs, and lower limbs. Each of these areas are assessed separately for the percentage of the area involved and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4, which translates to a numeric score that ranges from 0 (indicates no involvement) to 6 (90% to 100% involvement). The PASI produces a numeric score that can range from 0 (no disease) to 72 (maximal disease). For PASI75, the improvement threshold from baseline in PASI score is 75%. A higher score indicates more severe disease.

Time frame: Weeks 4, 8, 12, and 16

Percentage of Participants Who Achieved Psoriasis Area and Severity Index 90% Improvement (PASI90) Response at Weeks 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the BSA at Baseline

PASI is assessed in participants with psoriasis covering ≥ 3% of the BSA at Baseline. PASI is a system used for assessing and grading the severity of psoriatic lesions and their response to therapy. In the PASI system, the body is divided into 4 regions: the head and neck, trunk, upper limbs, and lower limbs. Each of these areas are assessed separately for the percentage of the area involved and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4, which translates to a numeric score that ranges from 0 (indicates no involvement) to 6 (90 percent \[%\] to 100% involvement). The PASI produces a numeric score that can range from 0 (no disease) to 72 (maximal disease). For PASI90, the improvement threshold from baseline in PASI score is 90%. A higher score indicates more severe disease.

Time frame: Weeks 4, 8, 12, and 16

Percentage of Participants Who Achieved Psoriasis Area and Severity Index 100% Improvement (PASI100) Response at Weeks 4, 8, 12, and 16 in Participants With Psoriasis Covering ≥ 3% of the BSA at Baseline

PASI is assessed in participants with psoriasis covering ≥ 3% of the BSA at Baseline. PASI is a system used for assessing and grading the severity of psoriatic lesions and their response to therapy. In the PASI system, the body is divided into 4 regions: the head and neck, trunk, upper limbs, and lower limbs. Each of these areas are assessed separately for the percentage of the area involved and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4, which translates to a numeric score that ranges from 0 (indicates no involvement) to 6 (90 percent \[%\] to 100% involvement). The PASI produces a numeric score that can range from 0 (no disease) to 72 (maximal disease). For PASI100, the improvement threshold from baseline in PASI score is 100%. A higher score indicates more severe disease.

Time frame: Weeks 4, 8, 12, and 16

Change From Baseline in Spondyloarthritis Research Consortium of Canada (SPARCC) Enthesitis Index at Weeks 4, 8, 12, and 16 in Participants With Enthesitis at Baseline

The enthesitis examination is based on the 16 anatomical sites: the medial epicondyle (left and right), the lateral epicondyle (left and right), the supraspinatus insertion (left and right), the bilateral greater trochanter (left and right), the quadriceps tendon insertion into superior border of patella (left and right), the patellar ligament insertion into inferior pole of patella or tibial tuberosity (left and right), the achilles tendon insertion (left and right), and the plantar fascia insertion (left and right). Enthesitis at each site is scored as either 0 (enthesitis absent) and 1 (enthesitis present). SPARCC enthesitis index has an overall total score ranging from 0 to 16. Higher score indicates a greater number of sites that are affected by enthesitis. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Change From Baseline in Leeds Dactylitis Index (LDI) at Weeks 4, 8, 12, and 16 in Participants With Dactylitis at Baseline

LDI quantitatively measures dactylitis using the circumference of involved digits and control digits and tenderness of involved digits. Digits affected by dactylitis are defined as those with an at least 10% difference in the ratio of circumference of the affected digit to the contralateral digit (digit on opposite hand or foot), or if contralateral digit is also affected, values from a standard reference table. Total score= {{\[Circumference involved digit/ Circumference contralateral Digit (or Tables)\] - 1}x 100} x Tenderness score. Tenderness score (0 = no tenderness, and 1 = tender). The difference between circumference of affected finger and contralateral not affected digit cannot be defined for maximum value. Therefore, it is difficult to provide scale range for the final score. No theoretical range exists for the Leeds Dactylitis Index. Lower Leeds Dactylitis Index score represent better outcome. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Change From Baseline in Tender Dactylitis Count (TDC) at Weeks 4, 8, 12, and 16 in Participants With Dactylitis at Baseline

Tender score (0 = no tenderness, 1 = tender, 2 = tender and wince, 3 = tender and withdraw) is collected for Dactylitis Assessments on the Dactylitis Score Sheet that is used for calculation of LDI total score. Tender dactylitis count (TDC) equals the number of tender fingers and toes (tendor score \>0). For participants with dactylitis status absent for all the fingers and toes, the TDC is set as 0. The total score range of TDC is from 0 to 60, higher scores indicate greater presence of dactylitis. A negative change from baseline indicates improvement.

Time frame: Baseline, 4, 8, 12, and 16 weeks

Change From Baseline in Health Assessment Questionnaire - Disability Index (HAQ-DI) Score at Weeks 2, 4, 8, 12, and 16

The HAQ-DI score is defined as the average of the scores of eight functional categories (dressing and grooming, arising, eating, walking, hygiene, reach, grip, and other activities), usually completed by the participant. Responses in each functional category are collected as 0 (without any difficulty) to 3 (unable to do a task in that area), with or without aids or devices. The eight category scores are averaged into an overall HAQ-DI score on a scale from 0 (no disability) to 3 (completely disabled). When 6 or more categories are non-missing, total possible score is 3. If more than 2 categories are missing, the HAQ-DI score is set to missing. A negative change from baseline indicates improvement (less disability).

Time frame: Baseline, 2, 4, 8, 12, and 16 weeks

Change From Baseline in Functional Assessment of Chronic Illness Therapy - Fatigue Scale (FACIT-Fatigue) Score at Weeks 4 and 16

FACIT-Fatigue scale is a brief, 13-item, symptom-specific questionnaire that specifically assesses the self-reported severity of fatigue and its impact upon daily activities and functioning in the past 7 days. The FACIT-Fatigue uses 0 (not at all) to 4 (very much) numeric rating scales for a total possible score of 0 to 52. Higher scores indicate less fatigue. Positive change in value indicates improvement (no or less severity of fatigue).

Time frame: Baseline, 4, and 16 weeks

Change From Baseline in Mental Component Score (MCS) of the 36-Item Short-Form Version 2 (SF-36v2) at Weeks 4 and 16

The SF-36 is a health-related survey that assesses participant's quality of life and consists of 36 questions covering 8 health domains: physical functioning, bodily pain, role limitations due to physical problems and emotional problems, general health, mental health, social functioning, vitality, and 2 component scores (MCS and PCS). MCS consists of social functioning, vitality, mental health, and role-emotional scales. Each domain is scored by summing the individual items and transforming the scores into a 0 to 100 scale with higher scores indicating better health status or functioning. A positive change from baseline indicated improvement (better health status).

Time frame: Baseline, 4, and 16 weeks

Change From Baseline in Physical Component Score (PCS) of the SF-36v2 at Weeks 4 and 16

The SF-36 is a health-related survey that assesses participant's quality of life and consists of 36 questions covering 8 health domains: physical functioning, bodily pain, role limitations due to physical problems and emotional problems, general health, mental health, social functioning, vitality, and 2 component scores (MCS and PCS). PCS consists of physical functioning, bodily pain, role-physical, and general health scales. Each domain is scored by summing the individual items and transforming the scores into a 0 to 100 scale with higher scores indicating better health status or functioning. A positive change from baseline indicates improvement (better health status).

Time frame: Baseline, 4, and 16 weeks