The psoriasis area and severity index (PASI) combines the assessment of the severity of lesions (scaling, redness and plaque thickness) and the area affected into a single score in the range of 0.0 (no disease) to 72.0 (maximal disease). The body is divided into four sections: (1) Head and neck; (2) Upper limbs; (3) Trunk (including axillae and groin); and (4) Lower limbs (including buttocks).

The PASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of psoriasis.

The PASI-75 response rate is defined as at least 75 percent (%) reduction in PASI score at EOT (up to 16 weeks) relative to Baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The PASI combines the assessment of the severity of lesions (scaling, redness and plaque thickness) and the area affected into a single score in the range of 0.0 (no disease) to 72.0 (maximal disease). The body is divided into four sections: (1) Head and neck; (2) Upper limbs; (3) Trunk (including axillae and groin); and (4) Lower limbs (including buttocks).

The PASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of psoriasis.

The PASI-50 response rate is defined as at least 50 percent (%) reduction in PASI score at EOT (up to 16 weeks) relative to Baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The PASI combines the assessment of the severity of lesions (scaling, redness and plaque thickness) and the area affected into a single score in the range of 0.0 (no disease) to 72.0 (maximal disease). The body is divided into four sections: (1) Head and neck; (2) Upper limbs; (3) Trunk (including axillae and groin); and (4) Lower limbs (including buttocks).

The PASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of psoriasis.

The PASI-90 response rate is defined as at least 90 percent (%) reduction in PASI score at EOT (up to 16 weeks) relative to Baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The PASI combines the assessment of the severity of lesions (scaling, redness and plaque thickness) and the area affected into a single score in the range of 0.0 (no disease) to 72.0 (maximal disease). The body is divided into four sections: (1) Head and neck; (2) Upper limbs; (3) Trunk (including axillae and groin); and (4) Lower limbs (including buttocks).

The PASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of psoriasis.

Percent change from baseline to EOT (up to 16 weeks) in PASI score was calculated by taking the PASI score at EOT and subtracting the baseline PASI score, then dividing by the baseline PASI score and multiplying by 100.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The sPGA of psoriasis is scored on a 5-point scale, reflecting a global consideration of the redness, thickness and scaling across all psoriatic lesions. Average redness, thickness and scaling are scored separately over the whole body according to a 5-point severity scale (0 [no symptoms] to 4 [severe symptoms]). The total score is calculated as average of the 3 severity (redness, thickness and scaling) scores and rounded to the nearest whole number score to determine the sPGA score (0=cleared; 1=minimal; 2=mild; 3=moderate; and 4=severe).

For this outcome measure, at EOT (up to 16 weeks), a score of 0 means no symptoms of psoriasis and a score of 1 means minimal symptoms of psoriasis.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The sPGA of psoriasis is scored on a 5-point scale, reflecting a global consideration of the redness, thickness and scaling across all psoriatic lesions. Average redness, thickness and scaling are scored separately over the whole body according to a 5-point severity scale (0 [no symptoms] to 4 [severe symptoms]). The total score is calculated as average of the 3 severity (redness, thickness and scaling) scores and rounded to the nearest whole number score to determine the sPGA score (0=cleared; 1=minimal; 2=mild; 3=moderate; and 4=severe).

Change from baseline to EOT (up to 16 weeks) in sPGA score was calculated by taking the sPGA score at EOT and subtracting the baseline sPGA score.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The total body surface area (BSA) affected by plaque-type psoriasis was obtained from the percentages of areas affected, including head, trunk, upper limbs and lower limbs. Each reported percentage was multiplied by its respective body region corresponding factor (head=0.1, upper limbs=0.2, trunk=0.3, lower limbs=0.4) and the resulting 4 values were added up to obtain the total psoriasis BSA (Range: 0 to 100).

BSA (%)=0.1Sh+0.2Su+0.3St+0.4Sl, where S=body region surface area with psoriasis: h=head; u=upper limbs; t=trunk; l=lower limbs.

Percent change from baseline to EOT (up to 16 weeks) in BSA was calculated by taking the EOT BSA and subtracting the baseline BSA, then dividing by the baseline BSA and multiplying by 100.

A negative change from baseline at EOT indicates a reduction in the Psoriasis BSA compared to the baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

Skindex-16 questionnaire contains 16 questions related to quality of life in subjects with skin disease. It consists of a short 16-item assessment completed by the subject, with each item rated on a 7-point Likert scale (0=never bothered to 6=always bothered). Each raw score is multiplied by 16.667 to transform all responses to a linear scale from 0 (no effect) to 100 (effect experienced all the time). Responses to the Skindex-16 are categorized into 3 subscales: symptom, emotional & functional; their respective scores are expressed in a linear scale from 0 to 100. Overall scale score is an average of 16 items expressed in a linear scale from 0 to 100.

Change from baseline to EOT (up to 16 weeks) in the Skindex-16 Overall Score was calculated by taking the EOT Skindex-16 Overall Score and subtracting the baseline Skindex-16 Overall Score.

A negative change from baseline at EOT indicates an improvement in the subject's condition compared to the baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

Skindex-16 questionnaire contains 16 questions related to quality of life in subjects with skin disease. It consists of a short 16-item assessment completed by the subject, with each item rated on a 7-point Likert scale (0=never bothered to 6=always bothered). Each raw score is multiplied by 16.667 to transform all responses to a linear scale from 0 (no effect) to 100 (effect experienced all the time). Responses to the Skindex-16 are categorized into 3 subscales: symptom, emotional & functional; their respective scores are expressed in a linear scale from 0 to 100. Symptoms scale score is an average of items 1 to 4 expressed in a linear scale from 0 to 100.

Change from baseline to EOT (up to 16 weeks) in the Skindex-16 Symptoms Scale Score was calculated by taking the EOT Skindex-16 Symptoms Scale Score and subtracting the baseline Skindex-16 Symptoms Scale Score.

A negative change from baseline at EOT indicates an improvement in the subject's condition compared to the baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

Skindex-16 questionnaire contains 16 questions related to quality of life in subjects with skin disease. It consists of a short 16-item assessment completed by the subject, with each item rated on a 7-point Likert scale (0=never bothered to 6=always bothered). Each raw score is multiplied by 16.667 to transform all responses to a linear scale from 0 (no effect) to 100 (effect experienced all the time). Responses to the Skindex-16 are categorized into 3 subscales: symptom, emotional & functional; their respective scores are expressed in a linear scale from 0 to 100. Emotions scale score is an average of items 5 to 11 expressed in a linear scale from 0 to 100.

Change from baseline to EOT (up to 16 weeks) in the Skindex-16 Emotions Scale Score was calculated by taking the EOT Skindex-16 Emotions Scale Score and subtracting the baseline Skindex-16 Emotions Scale Score.

A negative change from baseline at EOT indicates an improvement in the subject's condition compared to the baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

Skindex-16 questionnaire contains 16 questions related to quality of life in subjects with skin disease. It consists of a short 16-item assessment completed by the subject, with each item rated on a 7-point Likert scale (0=never bothered to 6=always bothered). Each raw score is multiplied by 16.667 to transform all responses to a linear scale from 0 (no effect) to 100 (effect experienced all the time). Responses are categorized into 3 subscales: symptom, emotional & functional; their respective scores are expressed in a linear scale from 0 to 100. Functioning scale score is an average of items 12 to 16 expressed in a linear scale from 0 to 100.

Change from baseline to EOT (up to 16 weeks) in the Skindex-16 Functioning Scale Score was calculated by taking the EOT Skindex-16 Functioning Scale Score and subtracting the baseline Skindex-16 Functioning Scale Score.

A negative change from baseline at EOT indicates an improvement in the subject's condition compared to the baseline.

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

The Itch NRS is a validated, self-reported, instrument for measurement of itch intensity and subjects were asked to rate the intensity of their itch on an 11-point scale ranging from 0 (no itch) to 10 (worst itch imaginable); higher scores indicated greater itch intensity. The Itch NRS scores were recorded by the subject using the e-diary once daily from screening through the last visit.

Change from baseline to EOT (up to 16 weeks) in the Itch NRS Score was calculated by taking the Itch NRS Score (weekly average) at EOT and subtracting the baseline Itch NRS Score (weekly average).

Subjects in the ITT Population at the EOT. The EOT value is defined as the last assessment during the treatment period (from the first dose of study drug to the last dose of study drug).

Subjects in the Safety Population (151, randomized subjects who received at least one dose of study drug).

The treatment-emergent adverse event (TEAE) is defined as one of the following:

1. An adverse event (AE) that occurred during the treatment period or the follow-up period. In the process of collecting the onset dates of AEs, an AE that occurs after the initiation of trial medication on Day 1 (the first day of the treatment period) should be treated as a TEAE. All AEs occurring on the day of first dose will be considered as TEAE if the time of AE occurrence relative to the dosing is unknown.
2. An AE present prior to the treatment period that worsened in severity during the treatment period or the follow-up period.
3. Any events that are present prior to the treatment period and have recovered, but recurred during the treatment period or the follow-up period should be considered as new TEAEs.

Safety Population (151, randomized subjects who received at least one dose of study drug).

Trough plasma concentration is the measured concentration at the end of a dosing interval at steady state (taken directly before next administration). Blood samples were collected at specific timepoints to measure trough plasma concentration of JTE-451 in the pharmacokinetic (PK) population.

Subjects (75 subjects) in the PK population at Week 16 with available trough plasma concentrations of JTE-451 (subjects who received at least one dose of JTE-451 and have at least one usable JTE-451 plasma concentration measurement at Week 16).