A Study With a Initial Treatment Period Followed by a Randomized-withdrawal Period to Evaluate the Efficacy and Safety of Bimekizumab in Adult Subjects With Moderate to Severe Chronic Plaque Psoriasis

A PASI90 responder was defined as a participant that achieved 90% reduction from Baseline in the PASI score. Body divided into 4 areas: head/arms/trunk to groin/legs to top of buttocks. Assignment of an average score for the redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear)-4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0-6 scale. Final PASI=average redness, thickness, and scaliness of the psoriatic skin lesions, multiplied by the involved psoriasis area score of the respective section, and weighted by the percentage of the person's affected skin for the respective section. The min possible PASI score is 0=no disease, the max score is 72=maximal disease. Study participants with missing score at Week 16 were counted as nonresponders (NRI).

The Investigator's Global Assessment (IGA) measures the overall psoriasis severity following a 5-point scale (0-4), where scale 0= clear, no signs of psoriasis; presence of post-Inflammatory hyperpigmentation, scale 1= almost clear, no thickening; normal to pink coloration; no to minimal focal scaling, scale 2= mild thickening, pink to light red coloration and predominately fine scaling, 3= moderate, clearly distinguishable to moderate thickening; dull to bright red, clearly distinguishable to moderate thickening; moderate scaling and 4= severe thickening with hard edges; bright to deep dark red coloration; severe/coarse scaling covering almost all or all lesions. IGA response was defined as Clear or Almost Clear with at least a 2-category improvement relative to Baseline. Study participants with missing score at Week 16 were counted as nonresponders (NRI).

A PASI100 responder was defined as a participant that achieved 100% reduction from Baseline in the PASI score. Body divided into 4 areas: head/arms/trunk to groin/legs to top of buttocks. Assignment of an average score for the redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear)-4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0-6 scale. Final PASI= average redness, thickness, and scaliness of the psoriatic skin lesions, multiplied by the involved psoriasis area score of the respective section, and weighted by the percentage of the person's affected skin for the respective section. The min possible PASI score is 0=no disease, the max score is 72=maximal disease. Study participants with missing score at Week 16 were counted as nonresponders (NRI).

The Investigator's Global Assessment (IGA) measures the overall psoriasis severity following a 5-point scale (0-4), where scale 0= clear, no signs of psoriasis; presence of post-inflammatory hyperpigmentation, scale 1= almost clear, no thickening; normal to pink coloration; no to minimal focal scaling, scale 2= mild thickening, pink to light red coloration and predominately fine scaling, 3= moderate, clearly distinguishable to moderate thickening; dull to bright red, clearly distinguishable to moderate thickening; moderate scaling and 4= severe thickening with hard edges; bright to deep dark red coloration; severe/coarse scaling covering almost all or all lesions. IGA response was defined as Clear with at least >= 2 category improvement relative to Baseline. Study participants with missing score at Week 16 were counted as nonresponders (NRI).

A PASI75 responder was defined as a participant that achieved 75% reduction from Baseline in the PASI score. Body divided into 4 areas: head/arms/trunk to groin/legs to top of buttocks. Assignment of an average score for the redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear)-4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0-6 scale. Final PASI= average redness, thickness, and scaliness of the psoriatic skin lesions, multiplied by the involved psoriasis area score of the respective section, and weighted by the percentage of the person's affected skin for the respective section. The min possible PASI score is 0=no disease, the max score is 72=maximal disease. Study participants with missing score at a given week were counted as nonresponders.

As PRO measure, the PSD (further published as P-SIM) was used to assess key symptoms relevant to patients with moderate to severe plaque psoriasis. Site staff trained participants on the use of the electronic device used to collect ePRO diary data at Screening, device was then dispensed to the participant for home use until Week 16 Visit. The ePRO diary was completed on daily basis from Screening to Week 16 Visit.

PSD pain item was assessed daily on a numeric rating scale (NRS) from 0 (no pain) to 10 (very severe pain). PSD score for pain at a given visit was an average of daily values over the week prior to the visit. The response was defined as an improvement (decrease) in pain score higher than the prespecified 1.98 response threshold at Week 16. The endpoint was characterized as percentage of participants with PSD pain response.

A PRO measure, the PSD (further published as P-SIM) was used to assess key symptoms relevant to patients with moderate to severe plaque psoriasis. Site staff trained participants on the use of the electronic device used to collect ePRO diary data at Screening, device was then dispensed to participant for home use until Week 16 Visit. The ePRO diary was completed on daily basis from Screening to Week 16 Visit.

PSD itch item was assessed daily on a NRS from 0 (no itch) to 10 (very severe itch). PSD score for itch was an average of daily values over the week prior to the visit. The response was defined as an improvement (decrease) in itch score higher than the prespecified 2.39 response threshold at Week 16. The endpoint was characterized as percentage of participants with a PSD itch response.

As PRO measure, the PSD (further published as P-SIM) was used to assess key symptoms relevant to patients with moderate to severe plaque psoriasis. Site staff trained participants on the use of the electronic device used to collect ePRO diary data at Screening, device was then dispensed to the participant for home use until Week 16 Visit. The ePRO diary was completed on daily basis from Screening to Week 16 Visit. PSD scaling item was assessed daily on a NRS from 0 (no scaling) to 10 (very severe scaling). PSD score for scaling was an average of daily values over the week prior to the visit. The response was defined as an improvement (decrease) in scaling score higher than the prespecified 2.86 response threshold at Week 16. The endpoint was characterized as percentage of participants with a PSD scaling response.

Only participants with scalp involvement at Baseline completed the scalp IGA. Participants with scalp involvement at Baseline were defined as those with a scalp IGA score >0 at Baseline. Scalp lesions were assessed in terms of clinical signs of redness, thickness, and scaliness using a 5-point scale (0=Clear, 1=Almost Clear, 2=Mild, 3=Moderate, 4= Severe). Scalp IGA 0/1 response at Week 16 was defined as clear (0) or almost clear (1) with at least a 2-category improvement from Baseline to Week 16.

A PASI90 responder was defined as a participant that achieved 90% reduction from Baseline in the PASI score. Study participants with missing score at Week 56 or who met the criterion for relapse were counted as nonresponders (NRI).

The number of TEAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the adverse event (AE) being considered. If a participant had no events, the total time at risk was used.

The number of SAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.

The number of TEAEs leading to discontinuation adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.

The number of TEAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the adverse event (AE) being considered. If a participant had no events, the total time at risk was used.

The number of SAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.

The number of TEAEs leading to discontinuation adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.

The number of TEAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the adverse event (AE) being considered. If a participant had no events, the total time at risk was used.

The number of SAEs adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.

The number of TEAEs leading to discontinuation adjusted by duration of exposure to study treatment was scaled such that it provides an incidence rate per 100 patient-years. If a participant had multiple events, the time of exposure was calculated to the first occurrence of the AE being considered. If a participant had no events, the total time at risk was used.