Study to Assess the Efficacy and Safety of Orismilast in Psoriasis

The Psoriasis Activity and Severity Index (PASI) is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI.

The PASI is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI. PASI75 is 75% reduction from Baseline in PASI score.

The IGA is a measure used by physicians to determine the patient's overall severity of disease. The static version is used in this trial for measurement at a single point in time as indicated in the schedule of assessments. The investigator will rate the severity of patient's psoriasis on a 5-point scale ranging from 0 (clear) to 4 (severe).

The IGA is a measure used by physicians to determine the patient's overall severity of disease. The static version is used in this trial for measurement at a single point in time as indicated in the schedule of assessments. The investigator will rate the severity of patient's psoriasis on a 5-point scale ranging from 0 (clear) to 4 (severe).

The PASI is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI. PASI75 is 75% reduction from Baseline in PASI score.

The PASI is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI. PASI 50, 90, and 100 is 50%, 90%, and 100% reduction from Baseline in PASI score, respectively.

The Psoriasis Activity and Severity Index (PASI) is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI.

The DLQI is a 10-item validated questionnaire completed by the patient used to assess the impact of skin disease on the patient's quality of life (QoL) during the previous week. The 10 questions cover the following topics: symptoms, embarrassment, shopping and home care, clothes, social and leisure, sport, work or study, close relationships, sex, and treatment. Each question is scored from 0 to 3 ("not at all," "a little," "a lot," and "very much," respectively), giving a total score ranging from 0 to 30. A high score is indicative of a poor QoL.

The BSA assessment estimates the extent of disease or skin affected by psoriasis and is expressed as a percentage of total body surface. BSA was determined by the Investigator or designee using the patient palm = 1% BSA rule. The patient's palm is measured from the wrist to the proximal interphalangeal and thumb.

The PSS is a 4-item patient-completed questionnaire (Rentz 2017). It is patient relevant, its domains are reliable and valid, and it takes few minutes to complete. The PSS assesses severity of pain, itching, redness, and burning during the past 24 hours using a 5-point severity scale from 0 = none to 4 = very severe.

The PSS is a 4-item patient-completed questionnaire (Rentz 2017). It is patient relevant, its domains are reliable and valid, and it takes few minutes to complete. The PSS assesses severity of pain, itching, redness, and burning during the past 24 hours using a 5-point severity scale from 0 = none to 4 = very severe.

The Psoriasis Activity and Severity Index (PASI) is a measure of psoriatic disease severity, taking into account qualitative lesion characteristics (erythema, induration, and desquamation) and percentage of affected skin surface area on defined anatomical regions. PASI score ranges from 0 to 72, with higher scores reflecting greater disease severity. Erythema, induration/thickness, and scaling are scored on a scale of 0 (none) to 4 (very severe) on 4 anatomic regions of the body: head, trunk, upper limbs, and lower limbs. Degree of involvement on each of the 4 anatomic regions is scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement). The total qualitative score (sum of erythema, thickness, and scaling scores) is multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The scores for each anatomic region are combined to yield the final PASI.