A Study to Evaluate the Efficacy and Safety of Bimekizumab in Adult Subjects With Moderate to Severe Chronic Plaque Psoriasis

The 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 \[0\] or almost clear \[1\] with at least a two-category improvement from Baseline at Week 16.

Time frame: Week 16

Population: The Randomized Set (RS) consisted of all randomized study participants. Both BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms are identical in terms of treatment received until Week 16 and therefore they are combined for analyses.

The PASI90 response assessments are based on at least 90% improvement in PASI score from Baseline. Body divided into 4 areas: head, arms, trunk to groin, and legs to top of buttocks. Assignment of an average score for redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear) to 4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0 to 6 scale. Final PASI= average redness, thickness, and scaliness of the psoriatic skin lesions, multiplied by the involved psoriasis area score of respective section, and weighted by the percentage of the person's affected skin for respective section. The minimum possible PASI score is 0= no disease, the maximum score is 72= maximal disease.

Time frame: Week 16

Population: The Randomized Set (RS) consisted of all randomized study participants. Both BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms are identical in terms of treatment received until Week 16 and therefore they are combined for analyses.

The number of SAEs adjusted by duration of exposure to study treatment was scaled such that it provided 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.

Time frame: From Baseline to Safety Follow-Up Visit (up to Week 72)

Population: The Bimekizumab Set (BKZ Set) consisted of all study participants who received at least 1 dose of bimekizumab in this study.

The number of SAEs adjusted by duration of exposure to study treatment was scaled such that it provided 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.

Time frame: From Baseline to Week 24

Population: The Safety Set (SS) consisted of all study participants that received at least 1 dose of IMP.

The number of TEAEs adjusted by duration of exposure to study treatment was scaled such that it provided 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.

Time frame: From Baseline to Safety Follow-Up Visit (up to Week 72)

Population: The Bimekizumab Set (BKZ Set) consisted of all study participants who received at least 1 dose of bimekizumab in this study.

The number of TEAEs adjusted by duration of exposure to study treatment was scaled such that provided 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.

Time frame: From Baseline to Week 24

Population: The Safety Set (SS) consisted of all study participants who received at least 1 dose of IMP.

The number of TEAEs leading to discontinuation adjusted by duration of exposure to study treatment was scaled such that it provided 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.

Time frame: From Baseline to Safety Follow-Up Visit (up to Week 72)

Population: The Bimekizumab Set (BKZ Set) consisted of all study participants who received at least 1 dose of bimekizumab in this study.

The number of TEAEs leading to discontinuation adjusted by duration of exposure to study treatment was scaled such that it provided 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.

Time frame: From Baseline to Week 24

Population: The Safety Set (SS) consisted of all study participants that received at least 1 dose of IMP.

The 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 \[0\] with at least a two-category improvement from Baseline at Week 24.

Time frame: Week 24

Population: The Randomized Set (RS) consisted of all randomized study participants. BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms were also combined for analyses purposes at Week 24 since they differ only one dose (Week 20).

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 \[0\]/almost clear \[1\] with at least a 2-category improvement from Baseline at Wk56.

Time frame: Week 56

Population: The RS consisted of all randomized study participants. ADA participants were not included as they did not start BKZ treatment at Baseline, thus did not have a year of BKZ treatment. The purpose of this table is to look at response after one year of BKZ.

The PASI100 response assessments are based on a 100% improvement in PASI score from Baseline. Body divided into 4 areas: head, arms, trunk to groin, and 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) to 4 (very marked). Determining the percentage of skin covered with PSO for each of body areas and converting to a 0 to 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 minimum possible PASI score is 0= no disease, the maximum score is 72= maximal disease.

Time frame: Week 16

Population: The Randomized Set (RS) consisted of all randomized study participants. Both BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms are identical in terms of treatment received until Week 16 and therefore they are combined for analyses.

The PASI100 response assessments are based on a 100% improvement in the PASI score from Baseline. Body divided into 4 areas: head, arms, trunk to groin, and 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) to 4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0 to 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 minimum possible PASI score is 0= no disease, the maximum score is 72= maximal disease.

Time frame: Week 24

Population: The Randomized Set (RS) consisted of all randomized study participants. BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms were also combined for analyses purposes at Week 24 since they differ only one dose (Week 20).

The PASI75 response assessments are based on at least 75% improvement in PASI score from Baseline. Body divided into 4 areas: head, arms, trunk to groin, and legs to top of buttocks. Assignment of an average score for redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear) to 4 (very marked). Determining the percentage of skin covered with PSO for each of body areas and converting to a 0 to 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 minimum possible PASI score is 0= no disease, the maximum score is 72= maximal disease.

Time frame: Week 4

Population: The Randomized Set (RS) consisted of all randomized study participants. Both BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms are identical in terms of treatment received until Week 16 and therefore they are combined for analyses.

The PASI90 response assessments are based on at least 90% improvement in the PASI score from Baseline. Body divided into 4 areas: head, arms, trunk to groin, and 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) to 4 (very marked). Determining the percentage of skin covered with PSO for each of the body areas and converting to a 0 to 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 minimum possible PASI score is 0= no disease, the maximum score is 72= maximal disease.

Time frame: Week 24

Population: The Randomized Set (RS) consisted of all randomized study participants. BKZ 320 mg Q4W and BKZ 320 mg Q4W/Q8W arms were also combined for analyses purposes at Week 24 since they differ only one dose (Week 20).

PASI90 response assessments are based on at least 90% improvement in the PASI score from Baseline. Body divided into 4 areas: head/arms/trunk to groin/and legs to top of buttocks. Assignment of an average score for the redness/thickness/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/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, max score is 72=maximal disease.

Time frame: Week 56

Population: The RS consisted of all randomized study participants. ADA participants were not included as they did not start BKZ treatment at Baseline, thus did not have a year of BKZ treatment. The purpose of this table is to look at response after one year of BKZ.