Participants initially randomized to receive placebo twice daily during the 16 week placebo controlled phase are re-randomized to 30 mg apremilast BID during the 8 week active treatment phase

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score at Week 16. The improvement in PASI score was used as a measure of efficacy The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score at Week 24. The improvement in PASI score was used as a measure of efficacy. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 16. The improvement in PASI score was used as a measure of efficacy. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 24. The improvement in PASI score was used as a measure of efficacy..The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was scored on a scale of 0 (no involvement) to 6 (90% to 100% involvement).

A participant was classified as having achieved a PASI-100 response if the PASI score was reduced by at least 100% from baseline. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

A participant was classified as having achieved a PASI-100 response if the PASI score was reduced by at least 100% from baseline. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

For PASI-100 responders in the placebo-controlled period weeks 0-16, time to achieve PASI-100 was the time interval, inclusive, between the date of randomization (day 1) and the date of the first assessment where PASI-90 was achieved.

The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score.

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

Area under the concentration versus time curve from time 0 (pre-dose) to 8 hours, calculated using the linear trapezoid rule.

Area under the concentration versus time curve from time 0 (pre-dose) to 8 hours, calculate using the linear trapezoid rule.

The maximum observed plasma concentration of apremilast observed at Week 14 (steady-state Cmax)

The maximum observed plasma concentration of apremilast observed at Week 24 (steady-state Cmax)

Time to achieve maximum plasma concentration (Cmax) observed at Week 14 (Time to achieve steady-state Tmax)

Time to achieve maximum plasma concentration (tmax) observed at Week 24 (Time to achieve steady-state Tmax)

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score at Week 52. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score at Week 32 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score at Week 40 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score at Week 32 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score at Week 16 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score at Week 52 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 32 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 40 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 52 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

A participant was classified as having achieved a PASI-100 response if the PASI score was reduced by at least 100% from baseline. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

A participant was classified as having achieved a PASI-100 response if the PASI score was reduced by at least 100% from baseline. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

A participant was classified as having achieved a PASI-100 response if the PASI score was reduced by at least 100% from baseline. The PASI score was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

For PASI-75 responders in the extension study, time to achieve PASI-75 was defined as the time interval, inclusive between the date of randomization (Day 1) and the date of the first assessment where PASI-75 was achieved.

For PASI-50 responders in the extension study, time to achieve PASI-50 was defined as the time interval, inclusive between the date of randomization (Day 1) and the date of the first assessment where PASI-50 was achieved.

For PASI-90 responders in the extension study, time to achieve PASI-90 was defined as the time interval, inclusive between the date of randomization (Day 1) and the date of the first assessment where PASI-90 was achieved.

For PASI-100 responders in the extension study, time to achieve PASI-100 was defined as the time interval, inclusive between the date of randomization (Day 1) and the date of the first assessment where PASI-100 was achieved.

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the subject and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the subject and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the subject and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value..

Dose response relationship using percent reduction in PASI scores across dose groups at Week 52 compared to Week 0

Time to 50% loss of the maximal improvement (achieved in either the core study or the extension study) during the treatment phase of the extension study, in participants who achieved ≥ PASI-50 in either the core study or during the treatment phase of the extension study

Time to loss of response was modified to be 50% loss in the PASI response observed at the end of treatment for participants who achieved at least a PASI-50 at the end of treatment. This definition was changed since participants may have already lost their maximal PASI response prior to enrollment into the Observation Follow-up Phase. Included all participants that enrolled into the observational follow-up phase after the treatment phase.

An AE was any noxious, unintended, or untoward medical occurrence, that may appear or worsen in a participant during the course of study. It may be a new intercurrent illness, a worsening concomitant illness, an injury, or any concomitant impairment of the participant's health, including laboratory test values regardless of etiology. Any worsening (ie, any clinically significant adverse change in the frequency or intensity of a preexisting condition) was considered an AE. A serious AE (SAE) is any untoward adverse event that is fatal, life-threatening, results in persistent or significant disability or incapacity, requires or prolongs existing in-patient hospitalization, is a congenital anomaly/birth defect, or is a condition that may jeopardize the patient or may require intervention to prevent one of the outcomes listed above. An AE is a treatment emergent AE if the AE start date is on or after the date of the first dose of study drug and no later than 28 days after the last dose.

An AE was any noxious, unintended, or untoward medical occurrence, that may appear or worsen in a participant during the course of study. It may be a new intercurrent illness, a worsening concomitant illness, an injury, or any concomitant impairment of the participant's health, including laboratory test values regardless of etiology. Any worsening (ie, any clinically significant adverse change in the frequency or intensity of a preexisting condition) was considered an AE. A serious AE (SAE) is any untoward adverse event that is fatal, life-threatening, results in persistent or significant disability or incapacity, requires or prolongs existing in-patient hospitalization, is a congenital anomaly/birth defect, or is a condition that may jeopardize the patient or may require intervention to prevent one of the outcomes listed above. An AE is a treatment emergent AE if the AE start date is on or after the date of the first dose of study drug and no later than 28 days after the last dose.

For PASI-50 responders in the placebo-controlled period weeks 0-16, time to achieve PASI-50 was defined as the time interval, inclusive between the date of randomization (day 1) and the date of the first assessment where PASI-50 was achieved.

For PASI-75 responders in the placebo-controlled period Weeks 0-16, time to achieve PASI-75 was defined as the time interval, inclusive between the date of randomization (day 1) and the date of the first assessment where PASI-75 is achieved.

For PASI-90 responders in the placebo-controlled period weeks 0-16, time to achieve PASI-90 was the time interval, inclusive, between the date of randomization (day 1) and the date of the first assessment where PASI-90 was achieved.

An AE was any noxious, unintended, or untoward medical occurrence, that may appear or worsen in a participant during the course of study. It may be a new intercurrent illness, a worsening concomitant illness, an injury, or any concomitant impairment of the participant's health, including laboratory test values regardless of etiology. Any worsening (ie, any clinically significant adverse change in the frequency or intensity of a preexisting condition) was considered an AE. A serious AE (SAE) is any untoward adverse event that is fatal, life-threatening, results in persistent or significant disability or incapacity, requires or prolongs existing in-patient hospitalization, is a congenital anomaly/birth defect, or is a condition that may jeopardize the patient or may require intervention to prevent one of the outcomes listed above. An AE is a treatment emergent AE if the AE start date is on or after the date of the first dose of study drug and no later than 28 days after the last dose.

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-75 response is the percentage of participants who achieved at least a 75% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-50 response is the percentage of participants who achieved at least a 50% reduction (improvement) from baseline in PASI score. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 76 of the long-term extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 100 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 148 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-90 response is the percentage of participants who achieved at least a 90% reduction (improvement) from baseline in PASI score at Week 196 of the extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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).

PASI-100 response is the percentage of participants who achieved at a 100% reduction (improvement) from baseline in PASI score of the long-term extension study. The improvement in PASI score was used as a measure of efficacy. The PASI was a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, 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 PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

The PASI is a measure of psoriatic disease severity taking into account qualitative lesion characteristics (erythema, thickness, and scaling) and degree of skin surface area involvement on defined anatomical regions. PASI scores range from 0 to 72, with higher scores reflecting greater disease severity. Erythema, thickness, and scaling were 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 was 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) was multiplied by the degree of involvement for each anatomic region and then multiplied by a constant. The values for each anatomic region were summed to yield the PASI score

Physician Global Assessment (sPGA) was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA is a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling. Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3).

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The overall BSA affected by psoriasis was estimated by comparison of the size of the affected area to the palm area of the participant's hand (entire palmar surface or "handprint"), which equates to approximately 1% of total BSA.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The DLQI was a validated, self-administered, 10-item questionnaire that measures the impact of skin disease on subjects' quality of life, based on recall over the past week. Domains include symptoms, feelings, daily activities, social, leisure, work or studying, personal relationships and treatment. Each question on the extent of the impact of skin disease was answered on a scale of 0 (not at all) to 3 (very much); the total DLQI score ranged from 0 to 30. A DLQI score greater than 10 is indicative of severe psoriasis.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The SF-36 was a 36-item general health status instrument and consists of 8 scales: physical function (PF), role limitations-physical (RP), vitality (VT), general health perceptions (GH), bodily pain (BP), social function (SF), role limitations-emotional (RE), and mental health (MH). Scale scores range from 0 to 100, with higher scores indicating better health. Two overall summary scores were obtained - a Physical Component Summary score (PCS) and a Mental Component Summary score (MCS). Scores from the 8 scales, PCS and MCS were transformed to the norm-based scores using weights from U.S. general population, with 50 as the average and 10 as the standard deviation, higher scores indicating better health. For norm based scores, change from baseline were calculated for the 8 scales and the two summary scales, where change = visit value - baseline value.

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease.

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less disease.

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease.

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease

The sPGA was a measure of psoriasis disease severity at the time of evaluation by the investigator. It does not compare assessments across visits or rely on investigator recall of prior disease severity. The sPGA was a 6-point scale ranging from 0 (clear, except for residual discoloration) to 5 (severe; majority of plaques have severe thickness, erythema, and scaling). The investigator examined all of the lesions on the participant and assigned a score ranging from 0 to 5 for thickness, erythema and degree of scaling . Scores for thickness, erythema and scaling are then summed and the mean of these 3 scores equaled the overall sPGA score. Fractional values for the sPGA were rounded to the next highest integer (eg, a score of 3.5 was rounded to 4, 3.4 was rounded to 3). A lower sPGA score was associated with less severe disease

Participants were initially randomized to apremilast (APR) 20 mg PO BID during the Placebo-controlled Phase (Weeks 0-16). Also includes those originally randomized to placebo that were re-randomized at Week 16 to APR 20 mg.

Participants were initially randomized to apremilast (APR) 30 mg PO BID during the Placebo-controlled Phase (Weeks 0-16). Also includes participants originally randomized to placebo that were re-randomized at Week 16 to APR 30 mg.

Participants who were initially randomized to placebo BID during the Placebo-controlled Phase (Weeks 0-16) were re-randomized at Week 16 to apremilast 20 mg PO BID and continued dosing with apremilast 20 mg BID during the active treatment phase (Weeks 16-24). At Week 24 (End of core study and beginning of extension study), participants were given the option to enroll into an extension study (PSOR-005E NCT00953875) and continued on the same apremilast dosage they had received at the end of the core study (Weeks 24-52). Participants who elected not to enter into the treatment extension study, completed a 4-week observational follow-up phase of the core study.

Participants who were initially randomized to placebo BID during the Placebo-controlled Phase (Weeks 0-16) were re-randomized at Week 16 to apremilast 30 mg PO BID and continued dosing with apremilast 30 mg PO BID during the active treatment phase (Weeks 16-24). At Week 24 (End of core study and beginning of extension study), participants were given the option to enroll into the extension study (PSOR-005E NCT00953875) and continued on the same apremilast dosage they had received at the end of the core study (Weeks 24-52). Participants who elected not to enter into the treatment extension study, completed a 4-week observational follow-up phase of the core study.