A Study to Evaluate the Efficacy and Safety of Different Doses of Bimekizumab in Subjects With Active Ankylosing Spondylitis (BE AGILE)

• ClinicalTrials.gov Identifier: NCT02963506
• Recruitment Status: Completed
• First Posted: November 15, 2016
• Results First Posted: November 16, 2020
• Last Update Posted: June 6, 2023
• Sponsor: UCB Biopharma S.P.R.L.
• Information provided by (Responsible Party): UCB Pharma ( UCB Biopharma S.P.R.L. )

• Study Type: Interventional
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor); Primary Purpose: Treatment
• Condition: Ankylosing Spondylitis
• Interventions: Other: Placebo; Drug: Bimekizumab
• Enrollment: 303

Participant Flow

Recruitment Details	The study started to enroll participants in October 2016 and concluded in August 2018.
Pre-assignment Details	The study included a 28-Day Screening Period, followed by a Double-Blind Period from Day 1 to Week 12, prior to treatment re-randomization, a Dose-blind Period, from Week 12 after the treatment re-randomization and up to Week 48 and a Safety Follow-Up (SFU) Period, post Week 48. The Participant Flow refers to the Randomized Set and Dose-Blind Set.

Arm/Group Title	Placebo	BKZ 16 mg	BKZ 64 mg	BKZ 160 mg	BKZ 320 mg	Placebo - BKZ 160 mg	Placebo - BKZ 320 mg	BKZ 16 mg - BKZ 160 mg	BKZ 16 mg - BKZ 320 mg	BKZ 64 mg - BKZ 160 mg	BKZ 64 mg - BKZ 320 mg	BKZ 160 mg - BKZ 160 mg	BKZ 320 mg - BKZ 320 mg
Arm/Group Description	Participants received placebo during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period.	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period.	After the 12 weeks Double-Blind Period participants randomized to placebo were re-randomized to receive bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) for 36 weeks in the Dose-Blind Period.	After the 12 weeks Double-Blind Period participants randomized to placebo were re-randomized to receive bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) for 36 weeks in the Dose-Blind Period	After the 12 weeks Double-Blind Period participants randomized to bimekizumab (BKZ) 16 mg every 4 weeks (Q4W) were re-randomized to receive BKZ 160 mg Q4W for 36 weeks in the Dose-Blind Period.	After the 12 weeks Double-Blind Period participants randomized to bimekizumab (BKZ) 16 mg every 4 weeks (Q4W) were re-randomized to receive BKZ 320 mg Q4W for 36 weeks in the Dose-Blind Period.	After the 12 weeks Double-Blind Period participants randomized to bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) were re-randomized to receive BKZ 160 mg Q4W for 36 weeks in the Dose-Blind Period.	After the 12 weeks Double-Blind Period participants randomized to bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) were re-randomized to receive BKZ 320 mg Q4W for 36 weeks in the Dose-Blind Period.	Participants randomized to bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) in the 12 weeks Double-Blind Period, continued to receive BKZ 160 mg Q4W in the 36 weeks Dose-Blind Period.	Participants randomized to bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) in the 12 weeks Double-Blind Period, continued to receive BKZ 320 mg Q4W in the 36 weeks Dose-Blind Period.
Period Title: Double-Blind Period
Started	60	61	61	60	61	0	0	0	0	0	0	0	0
Completed Double-Blind Period	60	59	59	58	61	0	0	0	0	0	0	0	0
Completed Week 12 - Started Dose-Blind	60	58	59	58	61	0	0	0	0	0	0	0	0
Completed	60	58	59	58	61	0	0	0	0	0	0	0	0
Not Completed	0	3	2	2	0	0	0	0	0	0	0	0	0
Reason Not Completed
Adverse Event	0	0	1	0	0	0	0	0	0	0	0	0	0
Death	0	0	0	1	0	0	0	0	0	0	0	0	0
Lost to Follow-up	0	1	0	0	0	0	0	0	0	0	0	0	0
Withdrawal by Subject	0	0	1	1	0	0	0	0	0	0	0	0	0
No compliance	0	1	0	0	0	0	0	0	0	0	0	0	0
Adverse event, non fatal after Wk12	0	1	0	0	0	0	0	0	0	0	0	0	0
Period Title: Dose-Blind Period
Started	0	0	0	0	0	24	36	31	27	34	25	58	61
Completed	0	0	0	0	0	20	31	26	24	30	24	56	54
Not Completed	0	0	0	0	0	4	5	5	3	4	1	2	7
Reason Not Completed
Adverse Event	0	0	0	0	0	1	3	2	2	2	1	1	6
Lack of Efficacy	0	0	0	0	0	0	0	1	0	1	0	0	0
Lost to Follow-up	0	0	0	0	0	1	0	0	1	0	0	1	0
Withdrawal by Subject	0	0	0	0	0	1	2	2	0	1	0	0	0
Sponsor decision	0	0	0	0	0	1	0	0	0	0	0	0	0
Meeting exclusion criteria 9	0	0	0	0	0	0	0	0	0	0	0	0	1

Baseline Characteristics

Arm/Group Title		Placebo	BKZ 16 mg	BKZ 64 mg	BKZ 160 mg	BKZ 320 mg	Total Title
Arm/Group Description		Participants received placebo during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period.	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period.	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period.	[Not Specified]
Overall Number of Baseline Participants		60	61	61	60	61	303
Baseline Analysis Population Description		The Baseline Characteristics refer to the Full Analysis Set (FAS), which consisted all randomized study participants who received at least 1 dose of investigational medicinal product (IMP) and had a valid measurement of the primary efficacy variable at Baseline.
Age, Categorical; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	60 participants	61 participants	61 participants	60 participants	61 participants	303 participants
	<=18 years	0 0.0%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	0 0.0%
	Between 18 and 65 years	60 100.0%	56 91.8%	59 96.7%	56 93.3%	60 98.4%	291 96.0%
	>=65 years	0 0.0%	5 8.2%	2 3.3%	4 6.7%	1 1.6%	12 4.0%
Age, Continuous; Mean (Standard Deviation); Unit of measure: Years
	Number Analyzed	60 participants	61 participants	61 participants	60 participants	61 participants	303 participants
		39.65 (10.30)	43.31 (12.59)	40.41 (10.93)	42.38 (13.11)	45.02 (11.39)	42.16 (11.80)
Sex: Female, Male; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	60 participants	61 participants	61 participants	60 participants	61 participants	303 participants
	Female	11 18.3%	8 13.1%	9 14.8%	8 13.3%	11 18.0%	47 15.5%
	Male	49 81.7%	53 86.9%	52 85.2%	52 86.7%	50 82.0%	256 84.5%
Race/Ethnicity, Customized; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	60 participants	61 participants	61 participants	60 participants	61 participants	303 participants
	American Indian/Alaskan Native	0 0.0%	0 0.0%	1 1.6%	0 0.0%	0 0.0%	1 0.3%
	White	60 100.0%	58 95.1%	60 98.4%	59 98.3%	61 100.0%	298 98.3%
	Other/Mixed	0 0.0%	3 4.9%	0 0.0%	1 1.7%	0 0.0%	4 1.3%

Outcome Measures

1. Primary Outcome

Title	Percentage of Participants With Axial Spondyloarthritis International Society 40% Response Criteria (ASAS40) at Week 12
Description	The ASAS40 response was defined as relative improvements of at least 40% and absolute improvement of at least 2 units on a 0 to 10 Numeric Rating Scale (NRS), where 0 is "not active" and 10 is "very active" in at least 3 of the 4 domains: Patient's Global Assessment of Disease Activity (PGADA), Pain assessment (total spinal pain NRS score), Function (Bath Ankylosing Spondylitis Functional Index (BASFI)), Inflammation (mean of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) questions 5 and 6 concerning morning stiffness intensity and duration) and no worsening at all in the remaining domain. Note: Participants with missing data or who discontinue study treatment prior to Week 12 were counted as non-responders.
Time Frame	Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of investigational medicinal product (IMP) and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Measure Type: Number; Unit of Measure: percentage of participants
	13.3	29.5	42.6	46.7	45.9

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS), BKZ 64 mg (FAS), BKZ 160 mg (FAS), BKZ 320 mg (FAS)
	Comments	Statistic and p-value were calculated using a Cochran-Mantel-Haenszel test (test for non-zero correlation statistic) based on modified ridit scores and including geographic region and prior Tumor Necrosis Factor (TNF) inhibitor exposure as stratification factors.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Cochran-Mantel-Haenszel
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Correlation statistic
	Estimated Value	17.9
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior tumor necrosis factor (TNF) inhibitor exposure.
	Type of Statistical Test	Other
	Comments	The pairwise testing of each bimekizumab dose versus placebo accounted for multiplicity by using a fixed sequence testing procedure with each bimekizumab dose being tested sequentially from the highest dose to the lowest dose. If the sequential testing failed to reach significance at a significance level of alpha=0.05, then the pairwise testing continued and the comparison was seen as non-significant.
Statistical Test of Hypothesis	P-Value	=0.040
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	2.6
	Confidence Interval	(2-Sided) 95%; 1.04 to 6.48
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	The pairwise testing of each bimekizumab dose versus placebo accounted for multiplicity by using a fixed sequence testing procedure with each bimekizumab dose being tested sequentially from the highest dose to the lowest dose. If the sequential testing failed to reach significance at a significance level of alpha=0.05, then the pairwise testing continued and the comparison was seen as non-significant.
Statistical Test of Hypothesis	P-Value	=0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.5
	Confidence Interval	(2-Sided) 95%; 1.83 to 10.86
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	The pairwise testing of each bimekizumab dose versus placebo accounted for multiplicity by using a fixed sequence testing procedure with each bimekizumab dose being tested sequentially from the highest dose to the lowest dose. If the sequential testing failed to reach significance at a significance level of alpha=0.05, then the pairwise testing continued and the comparison was seen as non-significant.
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.5
	Confidence Interval	(2-Sided) 95%; 2.27 to 13.48
	Estimation Comments	[Not Specified]

Statistical Analysis 5

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	The pairwise testing of each bimekizumab dose versus placebo accounted for multiplicity by using a fixed sequence testing procedure with each bimekizumab dose being tested sequentially from the highest dose to the lowest dose. If the sequential testing failed to reach significance at a significance level of alpha=0.05, then the pairwise testing continued and the comparison was seen as non-significant.
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.3
	Confidence Interval	(2-Sided) 95%; 2.19 to 12.92
	Estimation Comments	[Not Specified]

2. Secondary Outcome

Title	Change From Baseline in Ankylosing Spondylitis Disease Activity Score - C-Reactive Protein (ASDAS [CRP]) at Week 12
Description	The ASDAS was calculated as the sum of the following components: 0.121 x Back pain (BASDAI question 2 result) 0.058 x Duration of morning stiffness (BASDAI question 6 result) 0.110 x PGADA 0.073 x Peripheral pain/swelling (BASDAI question 3 result) 0.579 x (natural logarithm of the (hs-CRP [mg/L] + 1)) Back pain, PGADA, duration of morning stiffness, peripheral pain/swelling and fatigue are all assessed on a numerical scale (0 to 10 units). The change from Baseline is calculated, a negative value indicating improvement and a positive value worsening. There is a minimum score of 0.636 for the total ASDAS score, but no defined upper score since CRP does not have a set upper limit. If one component for the ASDAS-CRP was missing at a given visit, that component was imputed by carrying the last observation forward, and the ASDAS-CRP was calculated accordingly. If the hs-CRP value was below 2 mg/L, then it was imputed as the constant value of 2 mg/L.
Time Frame	From Baseline to Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of IMP and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Least Squares Mean (Standard Error); Unit of Measure: scores on a scale
	-0.3 (0.17)	-0.8 (0.17)	-1.4 (0.17)	-1.3 (0.17)	-1.4 (0.17)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	Least squares (LS) Mean, standard error, confidence interval and p-value were derived using the analysis of covariance (ANCOVA) model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-0.5
	Confidence Interval	(2-Sided) 95%; -0.86 to -0.24
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.16
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.2
	Confidence Interval	(2-Sided) 95%; -1.47 to -0.83
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.16
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.0
	Confidence Interval	(2-Sided) 95%; -1.35 to -0.72
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.16
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.1
	Confidence Interval	(2-Sided) 95%; -1.45 to -0.82
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.16
	Estimation Comments	[Not Specified]

3. Secondary Outcome

Title	Percentage of Participants With Axial Spondyloarthritis International Society 20% Response Criteria (ASAS20) at Week 12
Description	The ASAS20 response was defined as an improvement of at least 20% and absolute improvement of at least 1 unit on a 0 to 10 NRS, where 0 is "not active" and 10 is "very active" in at least 3 of the 4 domains: PGADA, Pain assessment (total spinal pain NRS scores), Function (BASFI), Inflammation (mean of BASDAI questions 5 and 6 concerning morning stiffness intensity and duration) and absence of deterioration in the potential remaining domain [deterioration was defined as a relative worsening of at least 20% and an absolute worsening of at least 1 unit]. Note: Participants with missing data or who discontinue study treatment prior to Week 12 were counted as non-responders.
Time Frame	Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of IMP and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Measure Type: Number; Unit of Measure: percentage of participants
	28.3	41.0	62.3	58.3	72.1

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.163
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	1.7
	Confidence Interval	(2-Sided) 95%; 0.80 to 3.67
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	3.9
	Confidence Interval	(2-Sided) 95%; 1.84 to 8.48
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	3.5
	Confidence Interval	(2-Sided) 95%; 1.66 to 7.61
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	6.5
	Confidence Interval	(2-Sided) 95%; 2.92 to 14.28
	Estimation Comments	[Not Specified]

4. Secondary Outcome

Title	Percentage of Participants With Axial Spondyloarthritis International Society (ASAS) 5/6 Response at Week 12
Description	The ASAS 5/6 response was defined as at least 20% improvement in at least 5 of the 6 domains: PGADA, Pain assessment (total spinal pain NRS scores), Function (BASFI), Inflammation (mean of BASDAI questions 5 and 6 concerning morning stiffness intensity and duration), spinal mobility (lateral spinal flexion) and high sensitivity C-reactive protein (hs-CRP). Note: Participants with missing data or who discontinue study treatment prior to Week 12 were counted as non-responders.
Time Frame	Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of IMP and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Measure Type: Number; Unit of Measure: percentage of participants
	6.7	29.5	49.2	53.3	54.1

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.003
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.3
	Confidence Interval	(2-Sided) 95%; 1.74 to 15.96
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	11.9
	Confidence Interval	(2-Sided) 95%; 4.03 to 35.38
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	14.3
	Confidence Interval	(2-Sided) 95%; 4.81 to 42.46
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	For differences in relation to placebo: Odds Ratio, confidence interval and p-value were derived from a logistic regression model including fixed effects for treatment, geographic region and prior TNF inhibitor exposure.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	The p-values were displayed as nominal p-values.
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	14.9
	Confidence Interval	(2-Sided) 95%; 5.02 to 44.27
	Estimation Comments	[Not Specified]

5. Secondary Outcome

Title	Change From Baseline to Week 12 in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)
Description	The BASDAI is a validated self-reported instrument, which consists of six 10-unit horizontal Numeric Rating Scales (NRS) to measure severity of fatigue, spinal and peripheral joint pain and swelling, enthesitis, and morning stiffness (both severity and duration, respectively) over the last week. The final BASDAI score ranges from 0 to 10, with lower scores indicating lower disease activity. The change from Baseline is calculated, a negative value indicating improvement and a positive value worsening. Note: Missing data was imputed using multiple imputation based on the Markov-Chain Monte Carlo method for the intermittent missing data, followed by monotone regression for the monotone missing data assuming missing at random.
Time Frame	From Baseline to Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of IMP and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Least Squares Mean (Standard Error); Unit of Measure: scores on a scale
	-1.0 (0.38)	-1.6 (0.38)	-2.6 (0.38)	-2.6 (0.38)	-2.9 (0.38)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.094
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-0.6
	Confidence Interval	(2-Sided) 95%; -1.31 to 0.10
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.6
	Confidence Interval	(2-Sided) 95%; -2.34 to -0.91
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.37
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.6
	Confidence Interval	(2-Sided) 95%; -2.35 to -0.91
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.37
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.9
	Confidence Interval	(2-Sided) 95%; -2.60 to -1.18
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

6. Secondary Outcome

Title	Change From Baseline to Week 12 in the Bath Ankylosing Spondylitis Functional Index (BASFI)
Description	The BASFI is a validated disease-specific instrument for assessing physical function. The BASFI comprises 10 items relating to the past week. The BASFI is the mean of the 10 scores such that the total score ranges from 0 (Easy) to 10 (Impossible), with lower scores indicating better physical function. The change from Baseline is calculated, a negative value indicating improvement and a positive value worsening. Note: Missing data was imputed using multiple imputation based on the Markov-Chain Monte Carlo method for the intermittent missing data, followed by monotone regression for the monotone missing data assuming missing at random.
Time Frame	From Baseline to Week 12

Outcome Measure Data

Analysis Population Description

The FAS consisted of all randomized participants who received at least 1 dose of IMP and had a valid measurement of the primary efficacy variable at Baseline.

Arm/Group Title	Placebo (FAS)	BKZ 16 mg (FAS)	BKZ 64 mg (FAS)	BKZ 160 mg (FAS)	BKZ 320 mg (FAS)
Arm/Group Description:	Participants received placebo during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).	Participants received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) during the 12 weeks Double-Blind Period followed by the same dose during the 36 weeks Dose-Blind Period, forming the Full Analysis Set (FAS).
Overall Number of Participants Analyzed	60	61	61	60	61
Least Squares Mean (Standard Error); Unit of Measure: scores on a scale
	-0.7 (0.39)	-1.4 (0.38)	-1.8 (0.38)	-1.9 (0.38)	-2.2 (0.38)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 16 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.075
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-0.6
	Confidence Interval	(2-Sided) 95%; -1.35 to 0.07
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 64 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.003
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.1
	Confidence Interval	(2-Sided) 95%; -1.79 to -0.37
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 160 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	=0.002
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.1
	Confidence Interval	(2-Sided) 95%; -1.84 to -0.42
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	Placebo (FAS), BKZ 320 mg (FAS)
	Comments	LS Mean, standard error, confidence interval and p-value were derived using the ANCOVA model with treatment, geographic region and prior TNF inhibitor exposure as fixed effects and the Baseline value as covariate.
	Type of Statistical Test	Other
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference vs placebo
	Estimated Value	-1.5
	Confidence Interval	(2-Sided) 95%; -2.22 to -0.81
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.36
	Estimation Comments	[Not Specified]

7. Secondary Outcome

Title	Percentage of Participants With at Least One Adverse Event (AE) During the Study
Description	An adverse event (AE) is any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.
Time Frame	From Screening until Safety Follow-Up Visit (up to Week 77)

Outcome Measure Data

Analysis Population Description

The SS consisted of all randomized participants who received at least 1 dose of IMP.

Arm/Group Title	Placebo (SS) - up to Wk 12	BKZ 16 mg (SS) - up to Wk 12	BKZ 64 mg (SS) - up to Wk 12	BKZ 160 mg (SS) - up to Wk 73	BKZ 320 mg (SS) - up to Wk 73
Arm/Group Description:	This arm consisted of all participants who received placebo at any time in the study (up to Week 12). Participants formed the Safety Set (SS).	This arm consisted of all participants who received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.
Overall Number of Participants Analyzed	60	61	58	149	150
Measure Type: Number; Unit of Measure: percentage of participants
	45.0	44.3	34.5	69.8	82.0

8. Secondary Outcome

Title	Percentage of Participants With at Least One Serious Adverse Event (SAE) During the Study
Description	A serious adverse event (SAE) is any untoward medical occurrence that at any dose: Results in death; Is life-threatening; Requires in patient hospitalisation or prolongation of existing hospitalisation; Is a congenital anomaly or birth defect; Is an infection that requires treatment parenteral antibiotics; Other important medical events which based on medical or scientific judgement may jeopardise the patients, or may require medical or surgical intervention to prevent any of the above.
Time Frame	From Screening until Safety Follow-Up Visit (up to Week 77)

Outcome Measure Data

Analysis Population Description

The SS consisted of all randomized participants who received at least 1 dose of IMP.

Arm/Group Title	Placebo (SS) - up to Wk 12	BKZ 16 mg (SS) - up to Wk 12	BKZ 64 mg (SS) - up to Wk 12	BKZ 160 mg (SS) - up to Wk 73	BKZ 320 mg (SS) - up to Wk 73
Arm/Group Description:	This arm consisted of all participants who received placebo at any time in the study (up to Week 12). Participants formed the Safety Set (SS).	This arm consisted of all participants who received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.
Overall Number of Participants Analyzed	60	61	58	149	150
Measure Type: Number; Unit of Measure: percentage of participants
	3.3	0	3.4	3.4	4.0

9. Secondary Outcome

Title	Percentage of Participants Who Withdrew Due to an Adverse Event (AE) During the Study
Description	An AE is any untoward medical occurrence in a participant or trial subject that is administered a drug or biologic (medicinal product) or that is using a medical device. The event does not necessarily have a causal relationship with that treatment or usage. The results of this Secondary Outcome Measure were summarized from the adverse event pages of the Case Report Forms.
Time Frame	From Screening until Safety Follow-Up Visit (up to Week 77)

Outcome Measure Data

Analysis Population Description

The SS consisted of all randomized participants who received at least 1 dose of IMP.

Arm/Group Title	Placebo (SS) - up to Wk 12	BKZ 16 mg (SS) - up to Wk 12	BKZ 64 mg (SS) - up to Wk 12	BKZ 160 mg (SS) - up to Wk 73	BKZ 320 mg (SS) - up to Wk 73
Arm/Group Description:	This arm consisted of all participants who received placebo at any time in the study (up to Week 12). Participants formed the Safety Set (SS).	This arm consisted of all participants who received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.	This arm consisted of all participants who received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.
Overall Number of Participants Analyzed	60	61	58	149	150
Measure Type: Number; Unit of Measure: percentage of participants
	1.7	3.3	1.7	4.7	6.7

Adverse Events

Time Frame	Treatment-emergent adverse events (TEAEs) were collected from Baseline until the Safety Follow-Up Visit (up to Week 73)
Adverse Event Reporting Description	At Week 12, placebo, BKZ 16 mg and BKZ 64 mg subjects were re-randomized to either BKZ 160 mg or BKZ 320 mg. Subjects randomized to BKZ 160 mg group or BKZ 320 mg at Baseline were not re-randomized at Week 12 and remained on their original treatment. The Safety Set is based on actual treatment, other populations are based on planned treatment.
Arm/Group Title	Placebo (SS) - up to Wk 12		BKZ 16 mg (SS) - up to Wk 12		BKZ 64 mg (SS) - up to Wk 12		BKZ 160 mg (SS) - up to Wk 73		BKZ 320 mg (SS) - up to Wk 73
Arm/Group Description	This arm consisted of all participants who received placebo at any time in the study (up to Week 12). Participants formed the Safety Set (SS).		This arm consisted of all participants who received bimekizumab (BKZ) 16 milligrams (mg) every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.		This arm consisted of all participants who received bimekizumab (BKZ) 64 mg every 4 weeks (Q4W) at any time in the study (up to Week 12). Participants formed the SS.		This arm consisted of all participants who received bimekizumab (BKZ) 160 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.		This arm consisted of all participants who received bimekizumab (BKZ) 320 mg every 4 weeks (Q4W) at any time in the study (up to Week 73). Participants formed the SS.
All-Cause Mortality
	Placebo (SS) - up to Wk 12		BKZ 16 mg (SS) - up to Wk 12		BKZ 64 mg (SS) - up to Wk 12		BKZ 160 mg (SS) - up to Wk 73		BKZ 320 mg (SS) - up to Wk 73
	Affected / at Risk (%)		Affected / at Risk (%)		Affected / at Risk (%)		Affected / at Risk (%)		Affected / at Risk (%)
Total	0/60 (0.00%)		0/61 (0.00%)		0/58 (0.00%)		1/149 (0.67%)		0/150 (0.00%)
Serious Adverse Events
	Placebo (SS) - up to Wk 12		BKZ 16 mg (SS) - up to Wk 12		BKZ 64 mg (SS) - up to Wk 12		BKZ 160 mg (SS) - up to Wk 73		BKZ 320 mg (SS) - up to Wk 73
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	2/60 (3.33%)		0/61 (0.00%)		2/58 (3.45%)		5/149 (3.36%)		6/150 (4.00%)
Blood and lymphatic system disorders
Anaemia * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	1/58 (1.72%)	1	0/149 (0.00%)	0	0/150 (0.00%)	0
Cardiac disorders
Acute myocardial infarction * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
Cardiac arrest * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
Ear and labyrinth disorders
Inner ear disorder * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Gastrointestinal disorders
Pancreatitis acute * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Crohn's disease * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Haemorrhoids * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	1/58 (1.72%)	1	0/149 (0.00%)	0	0/150 (0.00%)	0
Intestinal haemorrhage * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	1/58 (1.72%)	1	0/149 (0.00%)	0	0/150 (0.00%)	0
Abdominal pain * 1	1/60 (1.67%)	1	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	0/150 (0.00%)	0
Infections and infestations
Bursitis infective * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Abscess limb * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
Pilonidal cyst * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
Erysipelas * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	2	0/150 (0.00%)	0
Urinary tract infection * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
Postoperative wound infection * 1	1/60 (1.67%)	1	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	0/150 (0.00%)	0
Injury, poisoning and procedural complications
Foot fracture * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	1/58 (1.72%)	1	0/149 (0.00%)	0	0/150 (0.00%)	0
Laceration * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Musculoskeletal and connective tissue disorders
Osteoarthritis * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Colon adenoma * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	1/58 (1.72%)	1	0/149 (0.00%)	0	0/150 (0.00%)	0
Nervous system disorders
Dizziness * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	0/149 (0.00%)	0	1/150 (0.67%)	1
Respiratory, thoracic and mediastinal disorders
Pneumonia aspiration * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	1/149 (0.67%)	1	0/150 (0.00%)	0
1 Term from vocabulary, MedDRA19.0; * Indicates events were collected by non-systematic assessment
Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events	5%
	Placebo (SS) - up to Wk 12		BKZ 16 mg (SS) - up to Wk 12		BKZ 64 mg (SS) - up to Wk 12		BKZ 160 mg (SS) - up to Wk 73		BKZ 320 mg (SS) - up to Wk 73
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	2/60 (3.33%)		2/61 (3.28%)		4/58 (6.90%)		42/149 (28.19%)		56/150 (37.33%)
Infections and infestations
Oral candidiasis * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	8/149 (5.37%)	10	8/150 (5.33%)	11
Oral fungal infection * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	8/149 (5.37%)	8	6/150 (4.00%)	8
Bronchitis * 1	1/60 (1.67%)	1	0/61 (0.00%)	0	2/58 (3.45%)	2	4/149 (2.68%)	4	12/150 (8.00%)	12
Nasopharyngitis * 1	0/60 (0.00%)	0	2/61 (3.28%)	2	1/58 (1.72%)	1	13/149 (8.72%)	19	19/150 (12.67%)	22
Pharyngitis * 1	0/60 (0.00%)	0	0/61 (0.00%)	0	0/58 (0.00%)	0	11/149 (7.38%)	11	7/150 (4.67%)	7
Upper respiratory tract infection * 1	1/60 (1.67%)	1	0/61 (0.00%)	0	1/58 (1.72%)	1	5/149 (3.36%)	7	11/150 (7.33%)	11
1 Term from vocabulary, MedDRA19.0; * Indicates events were collected by non-systematic assessment

Limitations and Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There IS an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact

• Name/Title: UCB
• Organization: Cares
• Phone: +1844 599 ext 2273
• EMail: UCBCares@ucb.com

Publications of Results:

van der Heijde D, Gensler LS, Deodhar A, Baraliakos X, Poddubnyy D, Kivitz A, Farmer MK, Baeten D, Goldammer N, Coarse J, Oortgiesen M, Dougados M. Dual neutralisation of interleukin-17A and interleukin-17F with bimekizumab in patients with active ankylosing spondylitis: results from a 48-week phase IIb, randomised, double-blind, placebo-controlled, dose-ranging study. Ann Rheum Dis. 2020 May;79(5):595-604. doi: 10.1136/annrheumdis-2020-216980. Epub 2020 Apr 6. Erratum In: Ann Rheum Dis. 2020 Sep;79(9):e121. Ann Rheum Dis. 2021 Nov;80(11):e186.

Robinson PC, Machado PM, Haroon N, Gensler LS, Reveille JD, Taieb V, Vaux T, Fleurinck C, Oortgiesen M, de Peyrecave N, Deodhar A. Minimal Impact of the COVID-19 Pandemic on Disease Activity and Health-Related Quality of Life in Patients With Ankylosing Spondylitis Receiving Bimekizumab: Exploratory Analyses From a Phase 2b Open-Label Extension Study. ACR Open Rheumatol. 2022 Sep;4(9):819-824. doi: 10.1002/acr2.11486. Epub 2022 Jul 14.

• Responsible Party: UCB Pharma ( UCB Biopharma S.P.R.L. )
• ClinicalTrials.gov Identifier: NCT02963506
• Other Study ID Numbers: AS0008; 2016-001102-42 ( EudraCT Number )
• First Submitted: November 10, 2016
• First Posted: November 15, 2016
• Results First Submitted: October 21, 2020
• Results First Posted: November 16, 2020
• Last Update Posted: June 6, 2023