A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study to Evaluate the Efficacy and Safety of Bimekizumab in Chinese Adult Study Participants With Moderate to Severe Plaque Psoriasis
Phase: PHASE3
Conditions: Chronic Plaque Psoriasis, Moderate to Severe Chronic Plaque Psoriasis
Sponsor: UCB Biopharma SRL

UCB 
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Clinical Study Protocol 
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PS0041 
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A PHASE 3, MULTICENTER, RANDOMIZED, DOUBLE-BLIND, 
PLACEBO-CONTROLLED, PARALLEL GROUP STUDY TO 
EVALUATE THE EFFICACY AND SAFETY OF BIMEKIZUMAB 
IN CHINESE ADULT STUDY PARTICIPANTS WITH MODERATE 
TO SEVERE PLAQUE PSORIASIS 
PROTOCOL PS0041 AMENDMENT 2 
PHASE 3 
SHORT TITLE: 
A randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of 
bimekizumab in Chinese adult study participants with moderate to severe plaque psoriasis 
Sponsor: 
UCB Biopharma SRL 
Allée de la Recherche 60 
1070 Brussels 
BELGIUM 
Regulatory agency identifying number: 
NCT Number: 
Not applicable. 
Confidential Material 
Confidential 
This document is the property of UCB and may not – in full or in part – be passed on, 
reproduced, published, or otherwise used without the express permission of UCB. 
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PROTOCOL AMENDMENT SUMMARY OF CHANGES TABLE 
Document history 
Document 
Date 
Type of amendment 
Protocol amendment 2 
19 Apr 2023 
Not substantial 
Protocol amendment 1 
08 Feb 2023 
Substantial 
Original Protocol 
10 Oct 2022 
Not applicable 
 
Amendment 2 (19 Apr 2023) 
Overall Rationale for the Amendment 
The purpose of this amendment is to provide further clarification on the inclusion criteria and to 
be fully aligned with the pivotal global studies. 
Section # and Name 
Description of Change 
Brief Rationale 
5.1  Inclusion criteria 
 
Revised inclusion criterion #4 
Revised to align with global 
pivotal studies in psoriasis 
 
 
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SAFETY REPORTING OF ADVERSE EVENTS (SERIOUS AND 
NONSERIOUS) AND DEVICE DEFICIENCIES 
Safety reporting of adverse events (24h) 
Email 
Global: DS_ICT@ucb.com 
Fax 
+32 2 386 24 21 
 
Reporting of device deficiencies (24h) 
Email 
Global: qactscomplaints@ucb.com 
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TABLE OF CONTENTS 
PROTOCOL AMENDMENT SUMMARY OF CHANGES TABLE ...................................... 2 
1 
PROTOCOL SUMMARY ................................................................................................. 9 
1.1 
Synopsis ......................................................................................................................... 9 
1.2 
Schema ......................................................................................................................... 13 
1.3 
Schedule of Activities .................................................................................................. 14 
2 
INTRODUCTION ........................................................................................................... 18 
2.1 
Study rationale ............................................................................................................. 18 
2.2 
Background .................................................................................................................. 18 
2.2.1 
Current situation in China .................................................................................... 19 
2.3 
Benefit/risk assessment ................................................................................................ 20 
3 
OBJECTIVES AND ENDPOINTS ................................................................................. 21 
4 
STUDY DESIGN ............................................................................................................. 23 
4.1 
Overall design .............................................................................................................. 23 
4.2 
Scientific rationale for study design ............................................................................ 24 
4.3 
Justification for dose .................................................................................................... 25 
4.4 
End of study definition................................................................................................. 25 
5 
STUDY POPULATION .................................................................................................. 25 
5.1 
Inclusion criteria .......................................................................................................... 25 
5.2 
Exclusion criteria ......................................................................................................... 26 
5.3 
Screen failures .............................................................................................................. 29 
6 
STUDY TREATMENTS ................................................................................................. 30 
6.1 
Treatments administered .............................................................................................. 30 
6.1.1 
Medical devices ................................................................................................... 31 
6.2 
Preparation, handling, storage, and accountability requirements ................................ 31 
6.2.1 
Drug accountability ............................................................................................. 32 
6.3 
Measures to minimize bias: randomization and blinding ............................................ 32 
6.3.1 
Procedures for maintaining and breaking the treatment blind ............................. 33 
6.3.1.1 
Maintenance of study treatment blind ....................................................... 33 
6.3.1.2 
Breaking the treatment blind in an emergency situation ........................... 33 
6.4 
Treatment compliance .................................................................................................. 33 
6.5 
Concomitant medication(s)/treatment(s) ..................................................................... 34 
6.5.1 
Permitted concomitant treatments (medications and therapies) .......................... 34 
6.5.1.1 
Topical medications .................................................................................. 34 
6.5.1.2 
Other medications ...................................................................................... 34 
6.5.2 
Prohibited concomitant treatments (medications and therapies) ......................... 34 
6.5.3 
Vaccines ............................................................................................................... 36 
6.5.4 
Rescue medication ............................................................................................... 36 
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6.6 
Dose modification ........................................................................................................ 36 
6.7 
Criteria for study hold or dosing stoppage ................................................................... 36 
6.8 
Treatment after the end of the study ............................................................................ 36 
7 
DISCONTINUATION OF IMP AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL ........................................................................ 36 
7.1 
Discontinuation of IMP................................................................................................ 36 
7.1.1 
Potential drug-induced liver injury IMP discontinuation criteria ........................ 38 
7.1.1.1 
Follow-up evaluation ................................................................................. 39 
7.1.2 
Clinical laboratory criteria ................................................................................... 39 
7.1.3 
Temporary discontinuation of IMP ..................................................................... 39 
7.1.4 
IMP restart/rechallenge ........................................................................................ 39 
7.2 
Participant discontinuation/withdrawal from the study ............................................... 39 
7.3 
Lost to follow up .......................................................................................................... 40 
8 
STUDY ASSESSMENTS AND PROCEDURES ........................................................... 40 
8.1 
Efficacy assessments .................................................................................................... 41 
8.1.1 
PASI ..................................................................................................................... 41 
8.1.2 
IGA 42 
8.1.3 
Patient Symptom Diary (Psoriasis-Symptom and Impact Measure) ................... 42 
8.1.4 
Scalp IGA ............................................................................................................ 43 
8.1.5 
Dermatology Life Quality Index ......................................................................... 43 
8.2 
Safety assessments ....................................................................................................... 44 
8.2.1 
Clinical safety laboratory assessments ................................................................ 44 
8.2.2 
Vital signs ............................................................................................................ 44 
8.2.3 
Physical examination ........................................................................................... 44 
8.2.4 
12-lead electrocardiogram ................................................................................... 45 
8.2.5 
Assessment and management of TB and TB risk factors .................................... 45 
8.2.5.1 
Definitions ................................................................................................. 45 
8.2.5.2 
Assessments at Screening .......................................................................... 46 
8.2.5.3 
Assessment and reporting of TB and TB risk factors during the study..... 48 
8.3 
Adverse events and SAEs ............................................................................................ 50 
8.3.1 
Time period and frequency for collecting AE and SAE information .................. 50 
8.3.2 
Method of detecting AEs and SAEs .................................................................... 50 
8.3.3 
Follow up of AEs and SAEs ................................................................................ 51 
8.3.4 
Regulatory reporting requirements for SAEs ...................................................... 51 
8.3.5 
Pregnancy ............................................................................................................ 51 
8.3.6 
AEs of special interest ......................................................................................... 51 
8.3.7 
Other safety topics of interest .............................................................................. 52 
8.3.8 
Anticipated SAEs ................................................................................................. 52 
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8.3.9 
Medical device AEs and device deficiencies ....................................................... 53 
8.3.9.1 
Time period for detecting medical device deficiencies ............................. 53 
8.3.9.2 
Follow up of ADEs and device deficiencies ............................................. 53 
8.3.9.3 
Prompt reporting of ADEs and device deficiencies to Sponsor ................ 54 
8.3.9.4 
Regulatory reporting requirements for ADEs and device deficiencies ..... 54 
8.4 
Safety signal detection ................................................................................................. 54 
8.5 
Treatment of overdose ................................................................................................. 54 
8.6 
Pharmacokinetics ......................................................................................................... 55 
8.7 
Biomarkers ................................................................................................................... 55 
8.8 
Immunogenicity assessments ....................................................................................... 55 
8.9 
Medical resource utilization and health economics ..................................................... 56 
9 
STATISTICAL CONSIDERATIONS ............................................................................. 56 
9.1 
Definition of analysis sets ............................................................................................ 56 
9.2 
General statistical considerations ................................................................................. 56 
9.2.1 
Multiplicity .......................................................................................................... 56 
9.3 
Planned efficacy/outcome analyses ............................................................................. 57 
9.3.1 
Analysis of the primary efficacy/primary endpoints ........................................... 57 
9.3.1.1 
Sensitivity analyses ................................................................................... 58 
9.3.2 
Secondary efficacy endpoint analyses ................................................................. 58 
9.3.2.1 
Key secondary efficacy endpoint analyses ................................................ 58 
9.3.2.2 
Additional secondary efficacy endpoint analyses ..................................... 58 
9.3.3 
Tertiary efficacy endpoint analyses ..................................................................... 59 
9.4 
Planned safety and other analyses................................................................................ 59 
9.4.1 
Safety analyses ..................................................................................................... 59 
9.4.1.1 
AEs 59 
9.4.1.2 
Hematology/biochemistry ......................................................................... 60 
9.4.1.3 
Vital signs .................................................................................................. 60 
9.4.1.4 
Physical examination ................................................................................. 60 
9.4.2 
PK and ADAb analyses ....................................................................................... 60 
9.5 
Handling of protocol deviations................................................................................... 61 
9.6 
Handling of dropouts or missing data .......................................................................... 61 
9.7 
Planned analysis and data monitoring.......................................................................... 62 
9.8 
Determination of sample size ....................................................................................... 62 
10 SUPPORTING DOCUMENTATION AND OPERATIONAL CONSIDERATIONS... 63 
10.1 
Appendix 1: Regulatory, ethical, and study oversight considerations ......................... 63 
10.1.1 
Regulatory and ethical considerations ................................................................. 63 
10.1.2 
Financial disclosure ............................................................................................. 63 
10.1.3 
Informed consent process .................................................................................... 64 
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10.1.4 
Data protection ..................................................................................................... 64 
10.1.5 
Data quality assurance ......................................................................................... 65 
10.1.5.1 
eCRF completion ....................................................................................... 65 
10.1.6 
Source documents ................................................................................................ 65 
10.1.7 
Study and site closure .......................................................................................... 66 
10.1.8 
Publication policy ................................................................................................ 66 
10.2 
Appendix 2: Clinical laboratory tests .......................................................................... 67 
10.3 
Appendix 3: Adverse events – Definitions and procedures for recording, evaluating, 
follow up, and reporting ............................................................................................... 70 
10.4 
Appendix 4: Contraceptive guidance and collection of pregnancy information ......... 75 
10.5 
Appendix 5: Genetics ................................................................................................... 78 
10.6 
Appendix 6: Liver safety – suggested actions and follow-up assessments and IMP 
rechallenge guidelines .................................................................................................. 79 
10.6.1 
Consultation with Medical Monitor and local hepatologist................................. 83 
10.6.2 
Immediate action: determination of IMP discontinuation ................................... 83 
10.6.2.1 
IMP restart/rechallenge ............................................................................. 83 
10.6.3 
Testing: identification/exclusion of alternative etiology ..................................... 84 
10.7 
Appendix 7: Medical device AEs, ADEs, SAEs, and device deficiencies: definition 
and procedures for recording, evaluating, follow up, and reporting ............................ 87 
10.7.1 
Definition of AE and adverse device effect ......................................................... 87 
10.7.2 
Definition of SAE, SADE, and USADE ............................................................. 88 
10.7.3 
Definition of device deficiency ........................................................................... 88 
10.7.4 
Recording and follow up of AE and/or SAE and device deficiencies ................. 89 
10.8 
Appendix 8: Rapid alert procedures ............................................................................ 91 
10.9 
Appendix 9: Country-specific requirements ................................................................ 92 
10.10 Appendix 10: Abbreviations and trademarks .............................................................. 93 
10.11 Appendix 11: Protocol amendment history ................................................................. 96 
11 REFERENCES ................................................................................................................ 97 
SPONSOR DECLARATION .................................................................................................. 99 
 
LIST OF TABLES 
Table 1-1: 
Schedule of Activities ...................................................................................... 14 
Table 6-1: 
Treatments administered .................................................................................. 30 
Table 6-2: 
Dosing scheme ................................................................................................. 31 
Table 6-3: 
Prohibited concomitant treatments (medications and therapies) ..................... 35 
Table 8-1: 
Body areas for calculation of percent BSA for PASI ...................................... 42 
Table 8-2: 
Five-point IGA ................................................................................................. 42 
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Table 8-3: 
Scalp IGA......................................................................................................... 43 
Table 8-4: 
Anticipated SAEs for study participants with moderate to severe plaque 
PSO .................................................................................................................. 53 
Table 9-1: 
Sequence of hypothesis testing ........................................................................ 57 
Table 10-1: 
Protocol-required safety laboratory assessments ............................................. 68 
Table 10-2: 
Highly effective contraceptive methods .......................................................... 76 
Table 10-3: 
Required investigations and follow up for PDILI............................................ 80 
Table 10-4: 
PDILI laboratory measurements ...................................................................... 85 
Table 10-5: 
PDILI information to be collected ................................................................... 86 
 
LIST OF FIGURES 
Figure 1-1: 
Study schematic ............................................................................................... 13 
Figure 8-1: 
Decision tree for IGRA TB results at Screening ............................................. 47 
 
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1 
PROTOCOL SUMMARY 
1.1 
Synopsis 
Protocol title: A Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel 
group study to evaluate the efficacy and safety of bimekizumab in Chinese adult study 
participants with moderate to severe plaque psoriasis 
Short title: A randomized, double-blind, placebo-controlled study to evaluate the efficacy and 
safety of bimekizumab in Chinese adult study participants with moderate to severe plaque 
psoriasis 
Rationale: The purpose of this study is to evaluate the efficacy and safety of bimekizumab in 
Chinese adult study participants with moderate to severe plaque psoriasis (PSO) who are 
candidates for systemic PSO therapy and/or phototherapy. Following the completion of the 
global pivotal Phase 3 program of bimekizumab in moderate to severe plaque PSO, the aim of 
this study is to demonstrate the efficacy and safety of bimekizumab in adult Chinese study 
participants with moderate to severe plaque PSO. 
Objectives and endpoints 
Objectives 
Endpoints 
Primary 
Compare the efficacy of 
bimekizumab administered sc for 
16 weeks versus placebo in the 
treatment of study participants with 
moderate to severe plaque PSO 
Co-primary endpoint 1: 
• 
Participant-level outcome: PASI90 response at Week 16 
Co-primary endpoint 2: 
• 
Participant-level outcome: IGA 0/1 response at Week 16 
Secondary 
Key secondary 
Evaluate the efficacy of bimekizumab 
compared with placebo at achieving 
response (PASI75) at 4 weeks of 
treatment 
• 
Participant-level outcome: PASI75 response at Week 4 
Evaluate the efficacy of bimekizumab 
compared with placebo at achieving 
complete clearance (PASI100) at 
16 weeks of treatment 
• 
Participant-level outcome: PASI100 response at Week 16 
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Objectives 
Endpoints 
Additional secondary 
Evaluate the effect of bimekizumab 
compared with placebo on itch, pain, 
and scaling, as assessed by the 
PSD (P-SIM) response, at 16 weeks 
of treatment 
Reported by study participants using the PSD (also published 
as P-SIM [Gottlieb et al, 2020]): 
• 
Participant-level outcome: PSD (P-SIM) response for itch 
at Week 16 
• 
Participant-level outcome: PSD (P-SIM) response for pain 
at Week 16 
• 
Participant-level outcome: PSD (P-SIM) response for 
scaling at Week 16 
Assess the safety of bimekizumab 
through 16 weeks of treatment 
• 
Incidence of TEAEs through Week 16 
• 
Incidence of serious TEAEs through Week 16 
• 
Incidence of TEAEs leading to permanent discontinuation 
of IMP through Week 16 
Tertiary 
Assess the efficacy of bimekizumab 
in the treatment of study participants 
with moderate to severe plaque PSO 
over time 
• 
IGA 0 response over time 
• 
IGA 0/1 response over time 
• 
PASI75 response over time 
• 
PASI90 response over time 
• 
PASI100 response over time 
• 
Percentage of study participants with absolute PASI score 
≤1, ≤2, ≤3, and ≤5 over time 
• 
Time to PASI75, PASI90, and PASI100 response 
Assess the effect of bimekizumab on 
scalp PSO over time in study 
participants with scalp PSO at 
Baseline 
• 
Scalp IGA 0/1 response over time 
Evaluate the effect of bimekizumab 
over time on itch, pain, and scaling, 
and other items assessed by the 
PSD (P-SIM) 
• For each PSD (P-SIM) item score: change from 
Baseline over time 
Assess the effect of bimekizumab on 
health-related QoL over time 
• 
DLQI 0/1 response over time 
Assess the PK of bimekizumab over 
time 
• 
Plasma bimekizumab concentrations over time 
Assess the immunogenicity of 
bimekizumab prior to and following 
IMP administration 
• 
Anti-bimekizumab antibody levels prior to and following 
IMP administration 
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Objectives 
Endpoints 
Assess the safety and tolerability of 
bimekizumab throughout the study 
• 
Severity and frequency of TEAEs 
• 
Selected safety topics of interest TEAEs 
• 
Change from Baseline in clinical laboratory values 
(chemistry, hematology) 
• 
Change from Baseline in vital signs 
• 
Clinically significant changes in physical examination 
findings 
DLQI=Dermatology Life Quality Index; IGA=Investigator’s Global Assessment; IMP=investigational medicinal 
product; P-SIM=Psoriasis Symptom and Impact Measure; PASI=Psoriasis Area and Severity Index; 
PK=pharmacokinetic(s); PSD=Patient Symptom Diary; PSO=psoriasis; Q4W=every 4 weeks; QoL=quality of 
life; sc=subcutaneous(ly); scalp IGA=scalp-specific IGA; TEAE=treatment-emergent adverse event 
Note: During the 16-week Initial Treatment Period, study participants will receive either 
bimekizumab 320mg Q4W sc or placebo Q4W sc. During the Maintenance Treatment Period, study participants 
will receive treatment as described in Section 4.1. 
Note: The PASI75/90/100 response is defined as a 75% or greater/90% or greater/100% improvement from 
Baseline in the PASI score. 
Note: The IGA 0/1 response is defined as an IGA response of clear (0) or almost clear (1) with ≥2-category 
improvement relative to Baseline. 
Note: The PSD (P-SIM) response for itch/pain/scaling is defined as a score that has improved (decreased) 
by ≥4 points from Baseline (using weekly averages), and the study participant has not discontinued IMP. 
Note: The IGA 0 response is defined as an IGA response of clear (0) with ≥2-category improvement relative to 
Baseline. 
Note: The scalp IGA 0/1 response is defined as a scalp IGA response of clear (0) or almost clear (1) with a 
≥2-category improvement from Baseline. 
Note: The DLQI 0/1 response is defined as a DQLI total score equal to 0 or 1. 
Overall design 
PS0041 is a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group 
study to evaluate the efficacy and safety of bimekizumab in Chinese adult study participants with 
moderate to severe plaque PSO. 
The study population consists of Chinese adult study participants (≥18 years of age) with a 
diagnosis of moderate to severe plaque PSO (Baseline Psoriasis Area and Severity 
Index [PASI] ≥12 and body surface area [BSA] affected by PSO ≥10% and Investigator’s Global 
Assessment [IGA] score ≥3 on a 5-point scale) who are candidates for systemic PSO therapy 
and/or phototherapy. 
During the 16-week Initial Treatment Period, approximately 120 Chinese adult study participants 
will be randomized 3:1 to receive the following blinded investigational medicinal product (IMP) 
regimens: 
• Bimekizumab 320mg administered subcutaneously (sc) every 4 weeks (Q4W) (90 study 
participants) 
• Placebo administered sc Q4W (30 study participants) 
After completion of the 16-week Initial Treatment Period, study participants will enter the 
16-week Maintenance Treatment Period and study participants will return to the clinic Q4W. 
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The treatment during the Maintenance Treatment Period (Week 16 to Week 32) will be based on 
the following rules: 
• Study participants in the bimekizumab 320mg Q4W arm will receive 
bimekizumab 320mg every 8 weeks (Q8W). These study participants will also receive 
placebo injections at visits in between dosing with bimekizumab to maintain blinding 
procedures. 
• Study participants in the placebo arm will receive bimekizumab 320mg Q4W. 
Investigational medicinal product will be administered in the clinic by sc injection. 
After completion of the 16-week Maintenance Treatment Period, study participants will enter the 
Safety Follow-Up (SFU) Period after the final dose of IMP.  
Study participants withdrawing early from the study will undergo the Premature End of 
Treatment (PEOT) Visit assessments and will enter the 17-week SFU Period.  
All study participants, including those withdrawn from IMP, will have a SFU Visit 17 weeks 
after the final dose of IMP. 
A study participant will be considered to have completed the study if he/she completes all 
scheduled visits, up to and including Week 32 (regardless of completion of the SFU Visit). 
The end of the study is defined as the date of the final study participant's final visit in the study 
(including the SFU Visit). 
Number of participants 
Approximately 120 Chinese adult study participants will be randomly assigned to IMP for an 
estimated total of 90 evaluable study participants in the bimekizumab 320mg group and 30 study 
participants in the placebo group. 
Treatment groups and duration 
Study participants will be randomized 3:1 to 2 dose groups: bimekizumab 320mg or placebo. 
This study will include 4 periods: Screening Period (up to 5 weeks), Initial Treatment 
Period (16 weeks), Maintenance Treatment Period (16 weeks), and SFU Period (17 weeks after 
the final dose of IMP). 
 
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1.2 
Schema 
The study schematic is shown in Figure 1-1. 
Figure 1-1: Study schematic 
 
IGA 0/1=Investigator’s Global Assessment response clear (0) or almost clear (1) with ≥2-category improvement relative to Baseline; PASI90=90% or greater 
improvement from Baseline in the Psoriasis Area and Severity Index score; Q4W=every 4 weeks; Q8W=every 8 weeks; w=week 
 
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1.3 
Schedule of Activities 
Table 1-1: 
Schedule of Activities 
Visita/ 
Week 
 
Protocol activity 
Screening 
Initial Treatment Period 
(weeks after first dose) 
Maintenance Treatment Period 
(weeks after first dose) 
SFUb 
Baseline 
(first dose) 
1 
2 
4 
8 
12 
16 
20 
24 
28 
32/ 
PEOT 
Informed consent 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Inclusion/exclusion 
X 
X 
 
 
 
 
 
 
 
 
 
 
 
Urine drug screen 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Demographic data 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Psoriasis history 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Significant past medical 
history and concomitant 
diseases 
X 
Xc,d 
 
 
 
 
 
 
 
 
 
 
 
DLQI 
 
X 
 
 
X 
 
 
X 
X 
X 
 
X 
 
PSD (P-SIM) 
Physical exame  
X 
X 
 
 
 
 
 
X 
 
 
 
X 
X 
Height 
 
X 
 
 
 
 
 
 
 
 
 
 
 
Body weight 
X 
X 
 
 
 
 
 
  
 
 
 
X  
 
Vital signsf 
X 
X 
 
 
X 
 
 
X 
X 
 
 
X 
X 
Hematology and 
biochemistry 
X 
X 
 
 
X 
 
 
X 
X 
X 
 
X 
X 
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Table 1-1: 
Schedule of Activities 
Visita/ 
Week 
 
Protocol activity 
Screening 
Initial Treatment Period 
(weeks after first dose) 
Maintenance Treatment Period 
(weeks after first dose) 
SFUb 
Baseline 
(first dose) 
1 
2 
4 
8 
12 
16 
20 
24 
28 
32/ 
PEOT 
Urinalysis 
X 
X 
 
 
 
 
 
X 
 
 
 
X  
X 
ECG 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Pregnancy testingg 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Hepatitis B and C 
testingh 
X 
 
 
 
 
 
 
 
 
 
 
 
 
HIV testingi 
X 
 
 
 
 
 
 
 
 
 
 
 
 
Chest x-ray/CT scan j 
X 
 
 
 
 
 
 
 
 
 
 
 
 
IGRA TB test 
X 
 
 
 
 
 
 
 
 
 
X 
 
 
TB questionnaire 
X 
X 
 
 
 
 
 
X 
 
 
X 
X 
 
Blood sample for BKZ 
plasma concentration 
 
X 
X 
 
 
X 
 
X 
 
X 
 
X 
 
Blood sample for 
anti-BKZ antibodies 
 
X 
 
 
 
X 
 
X 
 
X 
 
X 
X 
PASI 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
IGA 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
Percentage of BSA 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
Scalp IGAk 
 
X 
X 
X 
X 
X 
X 
X 
 
 
 
X 
 
Concomitant 
medication 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
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Table 1-1: 
Schedule of Activities 
Visita/ 
Week 
 
Protocol activity 
Screening 
Initial Treatment Period 
(weeks after first dose) 
Maintenance Treatment Period 
(weeks after first dose) 
SFUb 
Baseline 
(first dose) 
1 
2 
4 
8 
12 
16 
20 
24 
28 
32/ 
PEOT 
AEs/ADE and device 
deficiency assessment 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
IRT
l  
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
BKZ or placebo 
administration
m,n 
 
X 
 
 
X 
X 
X 
X 
X 
X 
X 
 
 
Ab=antibody; ADE=adverse device effect; AE=adverse event; BKZ=bimekizumab; BSA=body surface area; CT=computed axial tomography; 
DLQI=Dermatology Life Quality Index; ECG=electrocardiogram; eCRF=electronic Case Report Form; HBcAb=anti-hepatitis B core antibody; 
HBsAg=hepatitis B surface antigen; HBV=hepatitis B virus; HCV=hepatitis C virus; HIV=human immunodeficiency virus; IGA=Investigator’s Global 
Assessment; IGRA=interferon-gamma release assay; IMP=investigational medicinal product; IRT=interactive response technology; P-SIM=Psoriasis 
Symptom and Impact Measure; PASI=Psoriasis Area and Severity Index; PEOT=Premature End of Treatment; PSD=Patient Symptom Diary; Q4W=every 
4 weeks; Q8W=every 8 weeks; scalp IGA=scalp-specific IGA; SFU=Safety Follow-Up; TB=tuberculosis 
Note: All assessments should be performed prior to IMP administration. The IMP administration is the starting point for the next administration period. Thus, 
the assessments in Week 16 and Week 32 belong to the previous treatment period. 
a For visits from the first dose of IMP through Week 32, the visit window is ±4 days from the scheduled visit. For the SFU Visit, the visit window is ±7 days 
from the scheduled visit. 
b The SFU Visit will occur 17 weeks after the final dose of IMP. 
c Ensure no significant changes in medical history. 
d Includes evaluation of signs and symptoms of active TB and risk for exposure to TB. 
e The physical examination will be performed as described in Section 8.2.3. 
f Vital signs (sitting systolic and diastolic blood pressure, pulse rate, and body temperature) are to be measured prior to blood sampling and prior to dosing, 
where applicable. 
g Pregnancy testing will consist of serum testing at Screening. A urine pregnancy test will be administered at all other visits. 
h Study participants who have evidence of or test positive for hepatitis B or C are excluded from the study, per Exclusion Criterion #9 (Section 5.2). A positive 
test for HBV is defined as: 1) positive for HBsAg or 2) positive for HBcAb. A positive test for HCV is defined as: 1) positive for anti-HCV Ab and 
2) positive via a confirmatory test for HCV (eg, HCV polymerase chain reaction). 
i The HIV test results will not be recorded in the eCRF. 
j Screening chest x-ray/CT scan must occur within 3 months prior to Screening Visit. 
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Table 1-1: 
Schedule of Activities 
Visita/ 
Week 
 
Protocol activity 
Screening 
Initial Treatment Period 
(weeks after first dose) 
Maintenance Treatment Period 
(weeks after first dose) 
SFUb 
Baseline 
(first dose) 
1 
2 
4 
8 
12 
16 
20 
24 
28 
32/ 
PEOT 
k The scalp IGA will be assessed for all study participants at Baseline. The scalp IGA will only be assessed at post-Baseline visits for those study participants 
with scalp involvement (scalp IGA score >0) at Baseline. 
l Investigational medicinal product administration is based on randomization. 
m To protect the blinding of the dosing regimen during the Maintenance Treatment Period, study participants receiving bimekizumab 320mg Q8W will also 
receive placebo injections at visits in between dosing so that all participants receive injections Q4W. 
n After a study participant completes the Week 16 assessments, which are the last assessments of the Initial Treatment Period, the dose of IMP for the 
Maintenance Treatment Period will be administered according to the randomization scheme. The final assessments of the Maintenance Treatment Period will 
be performed at Week 32. No IMP will be administered at Week 32. 
 
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2 
INTRODUCTION 
2.1 
Study rationale 
Psoriasis is a common, chronic inflammatory disease characterized by a series of linked cellular 
changes in the skin: hyperplasia of epidermal keratinocytes, vascular hyperplasia and ectasia, and 
infiltration of T lymphocytes, neutrophils, and other types of leukocytes in affected skin. 
Therapy for patients with PSO varies according to the severity of disease. Limited or mild 
disease is often treated with topical therapies such as corticosteroids and vitamin D analogs. 
Patients with more severe disease are often treated with phototherapy, methotrexate, 
cyclosporine, or biologic agents, such as tumor necrosis factor (TNF) antagonists, 
interleukin (IL)-12/23 inhibitors, IL-23p19 inhibitors, and IL-17A inhibitors. 
Bimekizumab is a humanized, full-length monoclonal antibody (mAb) of the 
immunoglobulin G1 (IgG1) subclass with 2 identical antigen-binding regions that potently and 
selectively bind and neutralize IL-17A, IL-17F, and IL-17AF cytokines. This property makes 
bimekizumab distinct from the other IL-17-targeting agents, like secukinumab and ixekizumab 
(selective anti-IL-17A cytokine targeting mAb) or brodalumab (anti-IL-17 receptor targeting 
mAb). Interleukin-17A and IL-17F are key proinflammatory cytokines believed to play 
important roles in autoimmune and inflammatory diseases. Therefore, bimekizumab permits an 
evaluation of the potential for additional efficacy, which may be conferred by dual inhibition of 
both cytokines, in patients suffering from diseases in which both cytokines are active. 
Bimekizumab was granted marketing authorization in the European Union and was approved in 
Great Britain, Canada, Saudi Arabia, and Australia for the treatment of moderate to severe 
plaque PSO in adults who are candidates for systemic therapy. In Japan, bimekizumab was 
approved for the treatment of plaque PSO, generalized pustular PSO, and psoriatic erythroderma. 
Bimekizumab is currently under review in other regions for moderate to severe plaque PSO. The 
completed Phase 3 bimekizumab plaque PSO studies provided 
 evidence of efficacy and 
an acceptable safety profile. UCB is also developing bimekizumab for the treatment of adults 
with psoriatic arthritis (PsA), axial spondyloarthritis, and hidradenitis suppurativa. Additionally, 
UCB has initiated the pediatric PSO program with a Phase 2 pharmacokinetics (PK) and safety 
study. 
The purpose of this study is to evaluate the efficacy and safety of bimekizumab in Chinese adult 
study participants with moderate to severe plaque PSO who are candidates for systemic PSO 
therapy and/or phototherapy. Following the completion of the global pivotal Phase 3 program of 
bimekizumab in moderate to severe plaque PSO, the aim of this study is to demonstrate the 
efficacy and safety of bimekizumab in adult Chinese study participants with moderate to severe 
plaque PSO. 
2.2 
Background 
Psoriasis is a common, chronic inflammatory disease characterized by inflammation and 
keratinocyte proliferation. Plaque PSO, the most common form of the disease, is typified by 
areas of red, inflamed skin, often covered with thick, micaceous, silver-colored scales on 
extensor surfaces. Plaques may be pruritic and painful as the skin cracks and bleeds. In severe 
cases, plaques grow and merge into one another, covering large areas. 
In addition to the impact on skin, PSO has a multitude of psychosocial and emotional effects on 
patients, including increased self-consciousness, frustration, fatigue, depression, and suicidal 
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ideation. As a result, patients frequently report sleeping problems, difficulties at work, problems 
interacting with family members, disrupted leisure activities, and sexual difficulties 
(Dowlatshahi et al, 2014; Gottlieb, 2005; Mukhtar et al, 2004; Ortonne, 2004; 
Krueger et al, 2001). 
A number of comorbidities have been associated with PSO, especially with more severe PSO. 
Psoriatic arthritis, cardiovascular (CV) disease, metabolic syndrome, chronic pulmonary disease, 
peptic ulcer disease, renal disease, and diabetes have all been demonstrated to have an increased 
prevalence in PSO patients (Yeung et al, 2013; Christophers et al, 2010; Gisondi et al, 2007; 
Gelfand et al, 2006). 
The reported prevalence of PSO in countries ranges between 0.09% and 11.43%, with 
≥100 million individuals affected worldwide (WHO report on psoriasis, 2016). There are a 
variety of forms of PSO, including plaque, guttate, inverse, pustular, and erythrodermic. Plaque 
PSO (PSO vulgaris) is the most common, comprising approximately 80% to 90% of all cases. It 
is estimated that approximately 80% of patients with plaque PSO have mild to moderate disease, 
while 20% of patients have more severe disease, which affects either greater than 5% of BSA or 
is located on high impact areas including the scalp, genitals, hands, and nails 
(Boehncke and Schön, 2015; Menter et al, 2008). 
Descriptions of nonclinical and clinical bimekizumab data, including the status of ongoing 
studies, are provided in the current version of the Investigator’s Brochure (IB). 
2.2.1 
Current situation in China 
A nationwide survey of mainland China in 1984 revealed that the prevalence of PSO was 0.16%, 
meaning there could be about 2 million patients with PSO in China, given its population of 
1.33 billion people as reported in the 2010 census (Shao et al, 1987). Since then, some 
epidemiological studies have been conducted in single cities or regions of China, mostly without 
statistically appropriate sampling design and data analysis (Li et al, 2013; Ding et al, 2012; 
Wang et al, 2012; Xu et al, 2001). The most recent study, conducted in 6 preselected cities in 
2008, found that the prevalence of PSO was 0.47%, meaning there could be about 6 million 
patients with PSO in China, a slight increase compared with the prevalence in 1984 
(Ding et al, 2012). 
In China, the treatment options are similar to options available globally. Limited or mild disease 
is often treated with corticosteroids, vitamin D analogs, and retinoids. Patients with more severe 
disease are often treated with photochemotherapy, immunosuppressants, or biologic agents. 
Biologics available in China include TNFα inhibitors (adalimumab) and IL inhibitors 
(ixekizumab, secukinumab, brodalumab, guselkumab, and ustekinumab). Some traditional 
Chinese medicines are also used to treat PSO, but there is a lack evidence for their efficacy and 
safety in this indication. 
The unmet needs in Chinese PSO patients are largely the same as unmet needs globally. These 
include therapy cessation due to an increased risk of developing serious infections, risk of 
malignancies, lack of response to therapy, or loss of response over time. 
Descriptions of nonclinical and clinical bimekizumab data, including the status of ongoing 
studies, are provided in the current version of the IB. 
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2.3 
Benefit/risk assessment 
Across the 3 pivotal Phase 3 studies (PS0008, PS0009, and PS0013; comparison against 
adalimumab or ustekinumab or placebo) and the Phase 3b study PS0015 (comparison against 
secukinumab), bimekizumab 320mg Q4W was effective for the PASI90, PASI100, and 
IGA 0/1 response endpoints in all prespecified subgroups, including, but not limited to, age, 
gender, race, body weight, Baseline disease severity, antidrug antibody (ADAb) status, 
neutralizing antibody status, prior biologic exposure (including prior anti-TNF and anti-IL-17 
exposure), and geographic region. There were no meaningful differences observed between 
subgroups of bimekizumab-treated study participants at Week 16 or at later time points, 
indicating that the safety profile of bimekizumab does not differ based on age, gender, race, or 
body weight. Therefore, although data were not collected from Chinese study participants in the 
completed global pivotal Phase 3 program, the benefits and risks of bimekizumab administration 
in Chinese adult study participants are expected to be similar to results in adult study participants 
with plaque PSO to date. 
In all studies of bimekizumab in moderate to severe plaque PSO mentioned above, study 
participants achieved and maintained skin clearance across multiple efficacy endpoints, as 
assessed by PASI (change from Baseline and by various levels of response) and IGA responses, 
after up to 56 weeks of bimekizumab 320mg sc treatment administered Q4W or 
bimekizumab 320mg sc treatment administered Q4W for an initial 16 weeks followed by 
Q8W maintenance treatment. The observed safety data were as expected considering the 
mechanism of action of bimekizumab and the population under investigation. The vast majority 
of adverse events (AEs) were nonserious, mild to moderate, and did not lead to IMP 
discontinuation. The most commonly reported treatment-emergent AEs (TEAEs) in 
bimekizumab-treated study participants were nasopharyngitis, oral candidiasis, and upper 
respiratory tract infection. 
Prespecified safety topics of interest for the study are as follows: infections (serious, 
opportunistic, fungal, and tuberculosis [TB]), neutropenia, hypersensitivity, injection site 
reactions, neuropsychiatric AEs (including suicidal ideation and behavior [SIB]), major CV 
events, liver function test (LFT) changes/enzyme elevations, malignancies, and inflammatory 
bowel disease (IBD). 
These are based on findings from the bimekizumab clinical program to date, potential risks 
generally associated with biologic immunomodulators, or findings from other medicines with a 
related mechanism of action. There are no specific AE reporting requirements for these topics; 
however, special monitoring, additional data collection activities, and/or enhanced signal 
detection activities (within UCB) are in place. 
More detailed information about the known and expected benefits and risks and reasonably 
expected AEs of bimekizumab may be found in the current version of the IB. 
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3 
OBJECTIVES AND ENDPOINTS 
Objectives 
Endpoints 
Primary 
Compare the efficacy of 
bimekizumab administered sc for 
16 weeks versus placebo in the 
treatment of study participants with 
moderate to severe plaque PSO 
Co-primary endpoint 1: 
• 
Participant-level outcome: PASI90 response at Week 16 
Co-primary endpoint 2: 
• 
Participant-level outcome: IGA 0/1 response at Week 16 
Secondary 
Key secondary 
Evaluate the efficacy of bimekizumab 
compared with placebo at achieving 
response (PASI75) at 4 weeks of 
treatment 
• 
Participant-level outcome: PASI75 response at Week 4 
Evaluate the efficacy of bimekizumab 
compared with placebo at achieving 
complete clearance (PASI100) at 
16 weeks of treatment 
• 
Participant-level outcome: PASI100 response at Week 16 
Additional secondary 
Evaluate the effect of bimekizumab 
compared with placebo on itch, pain, 
and scaling, as assessed by the 
PSD (P-SIM) response, at 16 weeks 
of treatment 
Reported by study participants using the PSD (also published 
as P-SIM [Gottlieb et al, 2020]): 
• 
Participant-level outcome: PSD (P-SIM) response for itch 
at Week 16 
• 
Participant-level outcome: PSD (P-SIM) response for pain 
at Week 16 
• 
Participant-level outcome: PSD (P-SIM) response for 
scaling at Week 16 
Assess the safety of bimekizumab 
through 16 weeks of treatment 
• 
Incidence of TEAEs through Week 16 
• 
Incidence of serious TEAEs through Week 16 
• 
Incidence of TEAEs leading to permanent discontinuation 
of IMP through Week 16 
Tertiary 
Assess the efficacy of bimekizumab 
in the treatment of study participants 
with moderate to severe plaque PSO 
over time 
• 
IGA 0 response over time 
• 
IGA 0/1 response over time 
• 
PASI75 response over time 
• 
PASI90 response over time 
• 
PASI100 response over time 
• 
Percentage of study participants with absolute PASI score 
≤1, ≤2, ≤3, and ≤5 over time 
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Objectives 
Endpoints 
• 
Time to PASI75, PASI90, and PASI100 response 
Assess the effect of bimekizumab on 
scalp PSO over time in study 
participants with scalp PSO at 
Baseline 
• 
Scalp IGA 0/1 response over time 
Evaluate the effect of bimekizumab 
over time on itch, pain, and scaling, 
and other items assessed by the 
PSD (P-SIM) 
• For each PSD (P-SIM) item score: change from 
Baseline over time 
Assess the effect of bimekizumab on 
health-related QoL over time 
• 
DLQI 0/1 response over time 
Assess the PK of bimekizumab over 
time 
• 
Plasma bimekizumab concentrations over time 
Assess the immunogenicity of 
bimekizumab prior to and following 
IMP administration 
• 
Anti-bimekizumab antibody levels prior to and following 
IMP administration 
Assess the safety and tolerability of 
bimekizumab throughout the study 
• 
Severity and frequency of TEAEs 
• 
Selected safety topics of interest TEAEs 
• 
Change from Baseline in clinical laboratory values 
(chemistry, hematology) 
• 
Change from Baseline in vital signs 
• 
Clinically significant changes in physical examination 
findings 
DLQI=Dermatology Life Quality Index; IGA=Investigator’s Global Assessment; IMP=investigational medicinal 
product; P-SIM=Psoriasis Symptom and Impact Measure; PASI=Psoriasis Area and Severity Index; 
PK=pharmacokinetic(s); PSD=Patient Symptom Diary; PSO=psoriasis; Q4W=every 4 weeks; QoL=quality of 
life; sc=subcutaneous(ly); scalp IGA=scalp-specific IGA; TEAE=treatment-emergent adverse event 
Note: During the 16-week Initial Treatment Period, study participants will receive either 
bimekizumab 320mg Q4W sc or placebo Q4W sc. During the Maintenance Treatment Period, study participants 
will receive treatment as described in Section 4.1. 
Note: The PASI75/90/100 response is defined as a 75% or greater/90% or greater/100% improvement from 
Baseline in the PASI score. 
Note: The IGA 0/1 response is defined as an IGA response of clear (0) or almost clear (1) with ≥2-category 
improvement relative to Baseline. 
Note: The PSD (P-SIM) response for itch/pain/scaling is defined as a score that has improved (decreased) 
by ≥4 points from Baseline (using weekly averages), and the study participant has not discontinued IMP. 
Note: The IGA 0 response is defined as an IGA response of clear (0) with ≥2-category improvement relative to 
Baseline. 
Note: The scalp IGA 0/1 response is defined as a scalp IGA response of clear (0) or almost clear (1) with a 
≥2-category improvement from Baseline. 
Note: The DLQI 0/1 response is defined as a DQLI total score equal to 0 or 1. 
 
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4 
STUDY DESIGN 
4.1 
Overall design 
PS0041 is a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group 
study to evaluate the efficacy and safety of bimekizumab in Chinese adult study participants with 
moderate to severe plaque PSO. 
The study population consists of Chinese adult study participants (≥18 years of age) with a 
diagnosis of moderate to severe plaque PSO (Baseline PASI ≥12 and BSA affected 
by PSO ≥10% and IGA score ≥3 on a 5-point scale) who are candidates for systemic PSO 
therapy and/or phototherapy. 
This study will include 4 periods: Screening Period (up to 5 weeks), Initial Treatment Period 
(16 weeks), Maintenance Treatment Period (16 weeks), and SFU Period (17 weeks after the final 
dose of IMP [Figure 1-1]). 
Screening Period 
The Screening Period will last up to a total of 5 weeks (for example, in cases where a laboratory 
assessment needs to be repeated or to allow washout of prohibited medications). During the 
Screening Period, eligible study participants will be informed about the study and sign the 
Informed Consent Form (ICF). Following signed informed consent, all screening procedures and 
laboratory tests (hematology, urine, and biochemistry) will be performed per the Schedule of 
Activities (SoA) (Table 1-1). A study participant newly diagnosed with a latent TB infection 
(LTBI) as a result of a positive IGRA screening test, may be rescreened once and enrolled after 
receiving ≥4 weeks of appropriate LTBI therapy and after consultation with the Medical 
Monitor. Further details of rescreening are provided in the exclusion criteria (Section 5.2). 
After completion of the Screening Period, eligible study participants will be allowed to enroll 
into the study. 
Initial Treatment Period 
During the 16-week Initial Treatment Period, approximately 120 Chinese adult study participants 
will be randomized 3:1 to receive the following blinded IMP regimens: 
• Bimekizumab 320mg administered sc Q4W (90 study participants) 
• Placebo administered sc Q4W (30 study participants) 
Investigational medicinal product will be administered in the clinic by sc injection at the visits 
specified in the SoA (Table 1-1). Study participants withdrawing early from the study will 
undergo the PEOT Visit assessments and will enter the SFU Period. 
Maintenance Treatment Period 
After completion of the Week 16 assessments, which are the last assessments in the 16-week 
Initial Treatment Period, study participants will enter the 16-week 
Maintenance Treatment Period. The first dose of IMP will be administered at Week 16 after all 
assessments are performed.  During the Maintenance Treatment Period, study participants will 
return to the clinic Q4W up to Week 32 to maintain the study blind. 
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The treatment during the Maintenance Treatment Period (Week 16 to Week 32) will be based on 
the following rules: 
• Study participants in the bimekizumab 320mg Q4W arm will receive 
bimekizumab 320mg Q8W. These study participants will also receive placebo injections at 
visits between dosing with bimekizumab to maintain blinding procedures. 
• Study participants in the placebo arm will receive bimekizumab 320mg Q4W. 
Safety Follow-Up Period 
After completion of the 16-week Maintenance Treatment Period, study participants will enter the 
SFU Period after the final dose of IMP.  
Study participants withdrawing early from the study will undergo the PEOT Visit assessments 
and will enter the SFU Period.  
All study participants, including those withdrawn from IMP, will have a SFU Visit 17 weeks 
after the final dose of IMP. 
4.2 
Scientific rationale for study design 
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4.3 
Justification for dose 
4.4 
End of study definition 
A study participant will be considered to have completed the study if he/she completes all 
scheduled visits, up to and including Week 32 (regardless of completion of the SFU Visit). 
The end of the study is defined as the date of the final study participant's final visit in the study 
(including the SFU Visit). 
5 
STUDY POPULATION 
Prospective approval of protocol deviations to recruitment and enrollment criteria, also known as 
protocol waivers or exemptions, is not permitted. 
5.1 
Inclusion criteria 
To be eligible to participate in this study, all of the following criteria must be met at Screening 
and at the Baseline Visit: 
1. Study participant has provided informed consent. 
2. Study participant is considered reliable and capable of adhering to the protocol (eg, able to 
understand and complete diaries), visit schedule, or IMP intake according to the judgment of 
the Investigator. 
3. Study participant is Chinese male or female ≥18 years of age. 
4. Study participant has plaque PSO for ≥6 months prior to the Screening Visit. 
5. Study participant has PASI ≥12 and BSA affected by PSO ≥10% and IGA score ≥3 on a 
5-point scale. 
6. Study participant is a candidate for systemic PSO therapy and/or phototherapy. 
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7. Female study participants must be: 
− Postmenopausal: Menopause is defined as 12 consecutive months of amenorrhea, for 
which there is no other obvious pathological or physiological cause. 
− Permanently sterilized (eg, tubal occlusion, hysterectomy, bilateral salpingectomy). 
− Or, if of childbearing potential (and engaged in sexual activity that could result in 
procreation), must be willing to use a highly effective method of contraception 
throughout the duration of the study until 17 weeks after last administration of IMP and 
have a negative pregnancy test at Visit 1 (Screening) and prior to first dose. The 
following methods are considered highly effective when used consistently and correctly: 
◦ 
Combined (estrogen and progestogen) hormonal contraception associated with 
inhibition of ovulation (oral, intravaginal, or transdermal). 
◦ 
Progestogen-only hormonal contraception associated with inhibition of ovulation 
(oral, injectable, implantable). 
◦ 
Intrauterine device. 
◦ 
Intrauterine hormone-releasing system. 
◦ 
Vasectomized partner. 
◦ 
Abstinence as a form of birth control is generally not allowed in the study unless 
abstinence is in accordance with a study participant’s preferred and common lifestyle. 
Study personnel must confirm the continued use of abstinence is in accordance with 
the study participant’s lifestyle at regular intervals during the study. 
Refer to Section 10.4 (Appendix 4) for further information about contraceptive guidance. 
8. Study participant agrees not to change their usual sun exposure during the course of the study 
and to use ultraviolet A/ultraviolet B sunscreens if unavoidable exposure occurs. 
5.2 
Exclusion criteria 
Study participants are not permitted to enroll in the study if any of the following criteria are met: 
1. Female study participant who is breastfeeding, pregnant, or plans to become pregnant during 
the study or within 17 weeks following the final dose of IMP. 
2. Study participant previously participated in a bimekizumab clinical study and received ≥1 
dose of the IMP (including placebo). 
3. Study participant previously participated in another study of a medication (systemic) under 
investigation within the last 12 weeks or at least 5 half-lives relative to Baseline, whichever 
is greater, or is currently participating in another study of a medication (systemic) under 
investigation. 
4. Study participant previously participated in another study of a topical medication under 
investigation within the last 4 weeks relative to Baseline or is currently participating in 
another study of a topical medication under investigation. 
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5. Study participant previously participated in another study of a medical device under 
investigation within the last 4 weeks relative to Baseline or is currently participating in 
another study of a medical device under investigation. 
6. Study participant has a known hypersensitivity to any excipients of bimekizumab. 
7. Study participant has a form of PSO other than chronic plaque-type (eg, pustular, 
erythrodermic, guttate, or drug-induced PSO). 
8. Study participant has an active infection or history of infection(s) as follows: 
− Any active systemic infection (except common cold) within 14 days prior to Baseline. 
− A serious infection, defined as requiring hospitalization or intravenous anti-infectives 
within 2 months prior to the first dose of IMP. 
− Recurrent or chronic infections that, in the opinion of the Investigator, might cause this 
study to be detrimental to the study participant. 
− Known history of opportunistic infections. Opportunistic infections are infections caused 
by uncommon pathogens (eg, pneumocystis carinii, cryptococcosis) or unusually severe 
infections caused by common pathogens (eg, cytomegalovirus, herpes zoster, candida). 
9. Study participant has concurrent acute or chronic viral hepatitis B or C or human 
immunodeficiency virus (HIV) infection. Study participants who have evidence of, or tested 
positive for, hepatitis B or hepatitis C are excluded. 
− A positive test for the hepatitis B virus (HBV) is defined as: 1) positive for hepatitis B 
surface antigen (HBsAg+), or 2) positive for anti-hepatitis B core antibody (HBcAb+). 
− A positive test for the hepatitis C virus (HCV) is defined as: 1) positive for hepatitis C 
antibody (anti-HCV Ab), and 2) positive via a confirmatory test for HCV (for example, 
HCV polymerase chain reaction). 
10. Study participant has received any live (includes attenuated) vaccination within the 8 weeks 
prior to Baseline (eg, inactivated influenza and pneumococcal vaccines are allowed, but nasal 
influenza vaccination is not permitted). 
11. Study participant has received Bacillus Calmette-Guerin vaccinations within 1 year prior to 
IMP administration. 
12. Study participant has known TB infection, is at high risk of acquiring TB infection, or has 
current or history of nontuberculous mycobacterium (NTMB) infection. A study participant 
newly diagnosed with LTBI as a result of a positive IGRA screening test may be rescreened 
once and enrolled after receiving ≥4 weeks of appropriate LTBI therapy, after consultation 
with the Medical Monitor, and if no evidence of therapy-related hepatotoxicity has occurred 
prior to the first injection (alanine aminotransferase [ALT]/aspartate aminotransferase [AST] 
remain ≤2 times upper limit of normal [ULN]). 
Study participant has a past history of active TB involving any organ system unless 
adequately treated according to World Health Organization/Center for Disease Control and 
Prevention therapeutic guidance and is proven to be fully recovered upon consult with a 
TB specialist. 
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Refer to Section 8.2.5.2 for details on TB assessments to be performed at Screening. 
13. Study participant has a history of a lymphoproliferative disorder, including lymphoma or 
current signs and symptoms suggestive of lymphoproliferative disease. 
14. Study participant has any active malignancy or history of malignancy within 5 years prior to 
the Screening Visit EXCEPT treated and considered cured cutaneous squamous or basal cell 
carcinoma, in situ cervical cancer, or ductal carcinoma in situ of the breast. 
15. Study participant has a diagnosis of inflammatory conditions other than PSO vulgaris or PsA, 
including, but not limited to, rheumatoid arthritis, sarcoidosis, inflammatory bowel disease, 
or systemic lupus erythematosus. 
16. Study participant has had major surgery (including joint surgery) within the 6 months prior to 
Screening or has planned major surgery within 6 months after entering the study. 
17. Study participant has any systemic disease (eg, renal failure, heart failure, hypertension, liver 
disease, diabetes, anemia) considered by the Investigator to be uncontrolled, unstable, or 
likely to progress to a clinically significant degree during the course of the study. 
18. Study participant has had myocardial infarction or stroke within the 3 months prior to the 
first dose of IMP. 
19. Study participant has laboratory abnormalities at Screening, including any of the following: 
− ≥3.0×ULN of any of the following: ALT, AST, alkaline phosphatase (ALP); or 
>ULN total bilirubin (≥1.5×ULN total bilirubin if known Gilbert’s syndrome) 
− White blood cell count <3.00×103/μL 
− Absolute neutrophil count <1.5×103/μL 
− Lymphocyte count <0.5×109/L 
− Hemoglobin <8.5g/dL 
− Any other laboratory abnormality, which, in the opinion of the Investigator, will prevent 
the study participant from completing the study or will interfere with the interpretation of 
the study results 
Individual screening tests for which the results are in error, borderline, or indeterminate for 
inclusion in the study can be repeated once. 
20. Study participant has any other condition, including medical or psychiatric, which, in the 
Investigator's judgment, would make the study participant unsuitable for inclusion in the 
study. 
21. Study participant has experienced primary failure to an IL-17 response modifier. Primary 
failure is defined as a study participant who did not respond to a biologic agent within 
12 weeks. 
22. Study participant has a history of chronic alcohol or drug abuse within 6 months prior to 
Screening as evaluated by the Investigator based on medical history, site interview, and/or 
results of the specified urine drug screen. 
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23. Study participant has presence of significant uncontrolled neuropsychiatric disorder, 
including major severe depression, active suicidal ideation, or positive suicide behavior, 
diagnosed by physicians. Study participants with history of suicide attempt within the 5 years 
prior to the Screening Visit must be excluded. Study participants with history of suicide 
attempt more than 5 years prior to the Screening Visit must be evaluated by a mental health 
care practitioner before enrollment. 
24. Study participant is a member of Investigator site personnel directly affiliated with this study 
and/or their immediate families. Immediate family is defined as a spouse, parent, child, or 
sibling, whether biological or legally adopted. 
25. Study participant is a UCB employee or employee of third-party organizations involved in 
the study. 
5.3 
Screen failures 
Screen failures are defined as study participants who consent to participate in the clinical study 
but are not subsequently randomized to study treatment. A minimal set of screen failure 
information is required to ensure transparent reporting of screen failure study participants to 
meet the Consolidated Standards of Reporting Trials publishing requirements and to respond to 
queries from regulatory authorities. Minimal information includes demography, screen failure 
details, eligibility criteria, and any SAE. 
For individuals who do not meet the criteria for participation in this study (ie, screen failures), 
1 rescreening may be allowed following consultation with and approval by the Medical Monitor. 
Rescreened study participants should be assigned a new study participant number. Reasons for 
rescreening include, but are not limited to, the following: 
• Study participant needs to complete a full course of therapy for LTBI and can be rescreened 
after completion of 4 weeks of prophylaxis prior to the first dose of IMP, as described in the 
exclusion criteria (Section 5.2). 
• Individual laboratory screening tests for which the results are exclusionary can be retested 
following consultation with and approval by the Medical Monitor. 
• Eligibility assessments could not be completed as planned (eg, for technical reasons) within 
the defined Screening Period without consultation with and approval by the Medical 
Monitor. 
• Study participant does not meet the required washout period for concomitant medications 
without consultation with and approval by the Medical Monitor (Section 6.5.2). 
For randomized study participants with a Baseline result >ULN for ALT, AST, ALP, or 
total bilirubin, a Baseline diagnosis and/or the cause of any clinically meaningful elevation must 
be understood and recorded in the electronic Case Report Form (eCRF). 
If a study participant has >ULN ALT, AST, or ALP that does not meet the exclusion limit 
at Screening, repeat the tests, if possible, prior to dosing to ensure there is no further ongoing 
clinically relevant increase. In case of a clinically relevant increase, inclusion of the study 
participant must be discussed with the Medical Monitor. 
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6 
STUDY TREATMENTS 
Investigational medicinal product is defined as any investigational treatment(s), marketed 
product(s), placebo, or medical device(s) intended to be administered to a study participant 
according to the study protocol. 
6.1 
Treatments administered 
During the 16-week Initial Treatment Period, eligible study participants will be randomized in a 
3:1 ratio to receive the following blinded IMP regimens: bimekizumab 320mg Q4W or placebo 
(Table 6-1). For bimekizumab treatment assignments during the Maintenance Treatment Period, 
see Section 4.1. 
Suitable areas for sc injections are the lateral abdominal wall, upper arm, and upper outer thigh. 
Study participants will receive 2 injections of IMP per dosing visit, and each of the injections 
should be administered at a separate injection site (eg, 1 injection in each arm or 1 in arm and 
1 in thigh). Injection sites should be rotated at each visit, and injections should not be given into 
a PSO plaque or areas where the skin is tender, bruised, erythematous, or indurated. The 
injection should last approximately 10 to 15 seconds. 
Further details of the IMPs and their specifications are provided in the IMP Handling Manual. 
Table 6-1: 
Treatments administered 
Arm name 
Bimekizumab 
Placebo 
IMP name 
Bimekizumab 320mg Q4W/Q8W 
Placebo 
Type 
Biologic 
N/A 
Dose formulation 
1mL PFS 
1mL PFS 
Unit dose strength(s) 
160mg/mL (55mM sodium acetate, 
220mM glycine, 0.04% polysorbate 
80 at pH 5.0) 
0.9% sodium chloride aqueous 
solution (physiological saline, 
preservative-free) of pharmacopoeia 
(USP/Ph.Eur) quality 
Dosage levels 
320mg Q4W/Q8W 
Placebo Q4W 
Route of administration 
sc injection 
sc injection 
Use 
Active 
Placebo comparator 
IMP  
IMP 
IMP 
Sourcing 
Provided centrally by the Sponsor 
Provided centrally by the Sponsor 
Packaging and labeling 
Each PFS will be labeled as 
required by China. 
Each PFS will be labeled as 
required by China. 
Former name 
UCB4940 
N/A 
IMP=investigational medicinal product; N/A=not applicable; PFS=prefilled syringe; Ph.Eur=European 
Pharmacopoeia; Q4W=every 4 weeks; Q8W=every 8 weeks; sc=subcutaneous; USP=United States 
Pharmacopoeia 
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The dosing scheme is presented in Table 6-2. 
Table 6-2: 
Dosing scheme 
Dose assignment 
Baseline  
(first dose) 
Initial Treatment Period 
(weeks after first dose) 
Maintenance Treatment Period 
(weeks after first dose) 
4 
8 
12 
16 
20 
24 
28 
32 
Bimekizumab 
320mg 
Q4W/Q8W 
●● 
●● 
●● 
●● 
●● 
○○ 
●● 
○○ 
NA 
Placebo/ 
bimekizumab 
320mg Q4W 
○○ 
○○ 
○○ 
○○ 
●● 
●● 
●● 
●● 
NA 
●=bimekizumab; IMP=investigational medicinal product; ○=placebo; NA=not applicable; Q4W=every 4 
weeks; Q8W=every 8 weeks 
Note: After a study participant completes the Week 16 assessments, which are the last assessments of the Initial 
Treatment Period, the dose of IMP for the Maintenance Treatment Period will be administered according to the 
randomization scheme. The final assessments of the Maintenance Treatment Period will be performed at 
Week 32. No IMP will be administered at Week 32. 
6.1.1 
Medical devices 
The UCB-manufactured medical device provided for use in this study is the 1mL PFS. 
Instructions for medical device use are provided in the IMP Handling Manual. 
All adverse device effects (ADEs) and device deficiency (including malfunction use error and 
inadequate labeling) shall be documented and reported by the Investigator throughout the study 
(see Section 8.3.9) and appropriately managed by the Sponsor. 
6.2 
Preparation, handling, storage, and accountability requirements 
Unblinded study staff will be responsible for preparation of the clinical study material, including 
recording the administration information on source documents and administration of the IMP as 
sc injections. The unblinded personnel will not be involved in the study in any way other than 
assuring the medication is taken from the correct kit and administering the IMP to the study 
participants. 
Only study participants enrolled in the study may receive IMP, and only authorized site staff may 
supply or administer IMP. All IMP must be stored in a secure, environmentally controlled, and 
monitored (manual or automated) area in accordance with the labeled storage conditions, with 
access limited to the Investigator and authorized site staff. 
The Investigator, institution, or the head of the medical institution (where applicable) is 
responsible for IMP accountability, reconciliation, and record maintenance (ie, receipt, 
reconciliation, and final disposition records). 
The Investigator or designee must confirm appropriate temperature conditions have been 
maintained during transit for all IMP received and any discrepancies are reported and resolved 
before use of the IMP. 
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In case an out-of-range temperature is noted, it must be immediately reported as per instructions 
contained in the IMP Handling Manual. 
Further guidance and information for the final disposition of unused IMP are provided in the 
IMP Handling Manual. 
6.2.1 
Drug accountability 
During the Initial Treatment Period and Maintenance Treatment Period of this study, the IMP 
will be administered in the clinic, and compliance will be determined at the visit by study 
personnel. 
The Drug Accountability Form will be used to record IMP dispensing and return information on 
a by-participant basis and will serve as source documentation during the course of the study. 
Details of any IMP lost, damaged (due to breakage or wastage), not used, partially used, 
disposed of at the study site, or returned to the Sponsor or designee must also be recorded on the 
appropriate forms. All supplies and pharmacy documentation must be made available throughout 
the study for UCB (or designee) to review. 
In order to maintain the blind, all IMP documentation (eg, shipping receipts, drug accountability 
logs, interactive response technology [IRT] randomization materials) must be maintained and 
accessed by unblinded, trained site personnel only. Designated, unblinded site personnel must be 
appropriately trained and licensed (per country guidelines) to administer injections. 
Unblinded study staff will be delegated the responsibility to receive, inventory, and destroy the 
used kits. The packaging identifies each kit by a unique number, but due to the open-label 
packaging, the unblinded study staff will be responsible in order to maintain the blind. Unblinded 
study staff will be responsible for preparation (breaking tamper proof sticker on kit, etc) of the 
clinical study material, including recording the administration information on source documents. 
The Investigator (or designee) is responsible for retaining all used, unused, and partially used 
containers of IMP until returned or destroyed. 
The Investigator may assign some of the Investigator’s duties for IMP accountability at the study 
site to an appropriate pharmacist/designee. 
The Investigator must ensure that the IMP is used only in accordance with the protocol. 
Periodically, and/or after completion of the clinical phase of the study, all used (including empty 
containers)/partially used, unused, damaged, and/or expired IMP must be reconciled and either 
destroyed at the site according to local laws, regulations, and UCB standard operating 
procedures, or returned to UCB (or designee). Investigational medicinal product intended for the 
study cannot be used for any other purpose than that described in this protocol. 
6.3 
Measures to minimize bias: randomization and blinding 
An IRT will be used for assigning eligible study participants to a treatment regimen 
(as applicable) based on a predetermined production randomization and/or packaging schedule 
provided by UCB (or designee). The randomization schedule will be produced by the IRT 
vendor. The IRT will generate individual assignments for kits of IMP, as appropriate, according 
to the visit schedule. 
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At the Screening Visit, each study participant will be assigned a 5-digit number that serves as the 
study participant identifier throughout the study. The study participant number will be required 
in all communication between the Investigator or designee and the IRT regarding a particular 
study participant. Once a study participant number has been assigned, it must not be reassigned. 
At the Baseline Visit, a study participant will be randomized into the study. The Investigator or 
designee will use the IRT for randomization. The IRT will automatically inform the Investigator 
or designee of the study participant’s randomization number. The IRT will allocate kit numbers 
to the study participant based on the randomization number during the course of the study. 
Study participant numbers, randomization numbers, and kit numbers will be tracked via the IRT. 
6.3.1 
Procedures for maintaining and breaking the treatment blind 
6.3.1.1 
Maintenance of study treatment blind 
All study participant treatment details (bimekizumab or placebo) will be allocated and 
maintained by the IRT system. 
In order to maintain the blind, all IMP documentation (eg, shipping receipts, drug accountability 
logs, IRT randomization materials) must be maintained and accessed by unblinded, trained site 
personnel only. Designated, unblinded site personnel must be appropriately trained and licensed 
(per China guidelines) to administer injections. 
Unblinded study staff will be delegated the responsibility to receive, inventory, and destroy the 
used IMP. The packaging identifies each kit by a unique number. Unblinded study staff will be 
responsible for preparation (breaking tamper proof sticker on kit, etc) of the IMP, including 
recording the administration information on source documents. To protect the blinding of the 
dosing regimen during the Maintenance Treatment Period, study participants receiving 
bimekizumab 320mg Q8W will also receive placebo injections at visits in between dosing so that 
all participants receive injections Q4W. 
6.3.1.2 
Breaking the treatment blind in an emergency situation 
The integrity of this clinical study must be maintained by observing the treatment blind. In the 
event of an emergency for which the appropriate treatment for a study participant cannot be 
made without knowing the treatment assignment, it will be possible to determine to which 
treatment arm and dose the study participant has been allocated by contacting the IRT. All sites 
will be provided with details of how to contact the system for code breaking at the start of the 
study. The Medical Monitor should be consulted prior to unblinding. 
The Clinical Project Manager (CPM) will be informed immediately via the IRT when a code is 
broken but will remain blinded to specific treatment information. Any unblinding of the IMP 
performed by the Investigator must be recorded in the source documents and on the 
Study Termination eCRF page. 
6.4 
Treatment compliance 
During the Initial Treatment Period and Maintenance Treatment Period of this study, the IMP 
will be administered in the clinic, and compliance will be determined at the visit by study 
personnel. Drug accountability must be recorded on the Drug Accountability Form 
(Section 6.2.1). 
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If a study participant is noncompliant with the study procedures or medications, in the opinion of 
the Investigator, then the study participant should be withdrawn as described in Section 7.2. 
6.5 
Concomitant medication(s)/treatment(s) 
Any medications/treatment administered from the time of informed consent to the final study 
visit will be considered concomitant medication/treatment. This includes medications/treatments 
that were started before the study and are ongoing during the study. 
6.5.1 
Permitted concomitant treatments (medications and therapies) 
6.5.1.1 
Topical medications 
The following concomitant topical medications are permitted during the study: 
• Study participants may continue to use topical moisturizers or emollients, bath oils, or 
oatmeal bath preparations for skin conditions during the study, as needed (PRN). 
Over-the-counter shampoos for the treatment of scalp PSO are also permitted. 
• Mild and low potency topical steroids will be permitted for use limited to the face, axilla, 
and/or genitalia, PRN. These topical medications should not be used within approximately 
24 hours prior to study visits requiring IGA and PASI measures. 
6.5.1.2 
Other medications 
Study participants who are receiving an established regimen for depression should remain on 
stable dosing prior to Baseline and throughout the study. Medication used to treat depression 
should be stable for 4 weeks prior to Baseline. 
6.5.2 
Prohibited concomitant treatments (medications and therapies) 
For prohibited prior medications, refer to the exclusion criteria (Section 5.2). 
Prohibited concomitant medications and therapies are outlined in Table 6-3. 
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Table 6-3: 
Prohibited concomitant treatments (medications and therapies) 
Drug 
Washout period relative to Baseline Visit 
Topicals, except for those permitted 
2 weeks 
Systemic retinoids 
1 month 
Systemic treatment (nonbiological): 
systemic immunosuppressant agents 
(eg, methotrexate, cyclosporine, azathioprine, 
thioguanine) 
fumaric acid esters specifically used for the 
treatment of PSO 
systemic corticosteroids 
phototherapy 
1 month 
Anti-TNFs: 
 
etanercept (including biosimilar) 
1 month 
infliximab (including biosimilar) 
golimumab 
certolizumab pegol 
adalimumab (including biosimilar) 
3 months 
Other biologics and other systemic therapies, eg: 
 
ustekinumab 
3 months 
apremilast, tofacitinib 
2 weeks 
guselkumab 
3 months 
rituximab 
3 months 
Anti-IL-17 therapya: 
secukinumab  
ixekizumab 
brodalumab 
3 months 
Any other antipsoriatic agent (systemic) under 
investigation (or approved after the protocol is 
approved) 
3 months or 5 half-lives, whichever is greater 
Any other antipsoriatic agent (systemic) not listed 
above 
3 months or 5 half-lives, whichever is greater 
Any other antipsoriatic agent (topical) under 
investigation 
1 month 
Traditional systemic Chinese medicine treatments for 
PSO and/or PsA 
1 month 
IL-17=interleukin 17; PsA=psoriatic arthritis; PSO=psoriasis; TNF=tumor necrosis factor 
a Bimekizumab is prohibited per exclusion criteria (Section 5.2). 
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Study participants who take prohibited medications may be withdrawn from IMP but followed 
until the SFU Visit. The decision to withdraw a study participant for taking prohibited 
medications should be made in consultation with the Medical Monitor. 
6.5.3 
Vaccines 
Administration of live (including attenuated) vaccines is not allowed during the conduct of the 
study and for 17 weeks after the final dose of IMP. Administration of inactivated vaccines is 
allowed during the study at the discretion of the Investigator in consultation with the Medical 
Monitor. 
Administration of any other type of vaccine that is not a live or inactivated vaccine must be 
discussed with the Medical Monitor. 
6.5.4 
Rescue medication 
No rescue medication is planned. 
6.6 
Dose modification 
No dose modifications are allowed during the Initial Treatment Period or Maintenance Treatment 
Period. 
6.7 
Criteria for study hold or dosing stoppage 
UCB reserves the right to temporarily suspend or prematurely discontinue this study either at a 
single site, multiple sites, or at all sites at any time for reasons, including, but not limited to, 
safety or ethical issues, inaccurate or incomplete data recording, noncompliance, or 
unsatisfactory enrollment with respect to quality or quantity. 
If the study is prematurely terminated or suspended, UCB (or its representative) will inform the 
Investigators/institutions and the regulatory authority(ies) of the termination or suspension and 
the reason(s) for the termination or suspension, in accordance with applicable regulatory 
requirement(s). The Institutional Review Board (IRB)/Independent Ethics Committee (IEC) 
should also be informed and provided with the reason(s) for the termination or suspension by the 
Sponsor or by the Investigator/institution, as specified by the applicable regulatory 
requirement(s). In addition, arrangements will be made for the return or destruction of all unused 
IMP and other material in accordance with UCB procedures for the study. 
6.8 
Treatment after the end of the study 
After the end of PS0041, study participants can switch to alternative treatments. 
7 
DISCONTINUATION OF IMP AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL 
7.1 
Discontinuation of IMP 
A study participant should be withdrawn from IMP and will be asked to come back for the 
SFU Visit 17 weeks after the final dose of IMP if any of the following events occur: 
1. Study participant develops an illness that, in the opinion of the Investigator, would interfere 
with his/her continued participation if the risk of continuing participation outweighs the 
potential benefit. 
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2. Study participant develops erythrodermic, guttate, or pustular form of PSO. 
3. Study participant is noncompliant with the study procedures or medications in the opinion of 
the Investigator. 
4. Study participant uses prohibited concomitant medications (as defined in Section 6.5.2) that 
may present a risk to the safety of the study participant or the integrity of the study data, in 
the opinion of the Investigator and/or the Medical Monitor. 
5. Study participant has a clinical laboratory value meeting any of the following criteria: 
− Hepatotoxicity as described in Section 7.1.1. 
− A laboratory value meeting any of the following criteria: 
◦ 
Absolute neutrophil count <1.0×103/μL 
◦ 
Absolute lymphocyte count <0.5×103/μL 
A study participant may remain in the study if the result is transient. A retest is required 
within 1 to 2 weeks at a scheduled or unscheduled visit. If the repeat absolute neutrophil 
count or absolute lymphocyte count is still below the allowable values, the study participant 
must be withdrawn. If the repeat absolute neutrophil count or absolute lymphocyte count is 
above the allowable values, the study participant may continue in the study. 
6. There is confirmation of a pregnancy during the study, as evidenced by a positive pregnancy 
test. See Section 10.4 (Appendix 4) for more information regarding pregnancies. 
7. Study participant experiences a severe AE, an SAE, or a clinically significant change in a 
laboratory value that, in the opinion of the Investigator, merits the discontinuation of IMP 
and appropriate measures being taken. 
8. Study participant considered as having either a suspected new LTBI or who develops an 
active TB or NTMB infection during the study must be immediately discontinued from IMP, 
and a PEOT Visit must be scheduled as soon as possible, but not later than the next regular 
visit. 
The study participant must be permanently withdrawn if further examinations result in a 
diagnosis of active TB or if the study participant is diagnosed with LTBI with no initiation of 
prophylactic treatment, prematurely discontinues prophylactic treatment, or, in the opinion of 
the Investigator or Sponsor, is noncompliant with prophylactic TB therapy. 
Confirmed active TB is an SAE and must be captured on an SAE Report Form and provided 
to the Sponsor in accordance with SAE reporting requirements. As with all SAEs, periodic 
follow-up reports should be completed as described in Section 10.3 (Appendix 3) until such 
time as the TB infection resolves. 
Additional information on TB policies is provided in (Section 8.2.5). 
9. Study participants with newly diagnosed IBD during the study must discontinue IMP. 
10. Study participant has SIB and/or any evidence of major depression. Study participants must 
be referred immediately to a mental health care professional for further assessment of any 
SIB and/or any evidence of major depression. Withdrawal is mandatory for suicidal behavior 
and/or a confirmed diagnosis of severe major depression. Otherwise, a withdrawal decision 
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will be based on the Investigator’s assessment of benefit/risk in consultation with the 
Medical Monitor. 
Investigators should attempt to obtain information on study participants in the case of withdrawal 
or discontinuation. For study participants considered as lost to follow up, the Investigator should 
make an effort (≥1 phone call and 1 written message to the study participant) and document 
his/her effort (date and summary of the phone call and copy of the written message in the source 
documents) to complete the final evaluation. All results of these evaluations and observations, 
together with a narrative description of the reason(s) for removing the study participant, must be 
recorded in the source documents. The eCRF must document the primary reason for withdrawal 
or discontinuation. 
Investigators should contact the Medical Monitor, whenever possible, to discuss withdrawal of a 
study participant in advance. 
7.1.1 
Potential drug-induced liver injury IMP discontinuation criteria 
Study participants with potential drug-induced liver injury(PDILI) must be assessed to determine 
if IMP must be discontinued. In addition, all concomitant medications and herbal supplements 
that are not medically necessary should also be discontinued. 
Immediate and permanent discontinuation of IMP is required for study participants with either of 
the following PDILI criteria: 
• ALT or AST ≥8×ULN 
• ALT or AST ≥3×ULN and coexisting total bilirubin ≥2×ULN 
Immediate discontinuation of IMP is required for study participants with the following 
PDILI criterion: 
• Study participants with ALT or AST ≥3×ULN who exhibit temporally associated symptoms 
of hepatitis or hypersensitivity. Hepatitis symptoms include fatigue, nausea, vomiting, and 
right upper quadrant pain or tenderness. Hypersensitivity symptoms may include fever 
(without clear alternative cause), rash, or eosinophilia. 
If a nondrug-related cause for the symptoms can be confirmed, these study participants may 
resume IMP administration after discussion with the responsible UCB Study Physician, but 
only when the requirements for rechallenge with IMP (as provided in 
Section 10.6 [Appendix 6]) are met. 
Study participants with the PDILI criterion below may be allowed to continue on IMP at the 
discretion of the Investigator: 
• Study participants with ALT or AST ≥5×ULN and <8×ULN, total bilirubin <2×ULN, and no 
eosinophilia, with no fever, rash, or symptoms of hepatitis (eg, fatigue, nausea, vomiting, 
right upper quadrant pain or tenderness). 
Evaluation of PDILI must be initiated (as described in Section 10.6 [Appendix 6]), with 
repeat tests performed in 2 weeks. Upon retest, if ALT or AST values have reduced 
to <5×ULN, the study participant can continue with the study. However, if ALT or AST 
values remain ≥5×ULN and <8×ULN after retest, IMP should be temporarily withheld, and 
study participant should undergo a repeat test in 2 weeks. If ALT or AST values remain 
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≥5×ULN even after the second retest, then the study participant should be permanently 
withdrawn from the study and should be followed for PDILI. 
If a study participant is unable to comply with the applicable monitoring schedule, IMP must 
be discontinued immediately. 
Investigators should attempt to obtain information on study participants in the case of IMP 
discontinuation to complete the final evaluation. Study participants with PDILI should not be 
withdrawn from the study until investigation and monitoring are complete. All results of these 
evaluations and observations, as well as the reason(s) for IMP discontinuation and study 
participant withdrawal (if applicable), must be recorded in the source documents. The eCRF 
must document the primary reason for IMP discontinuation. 
Specific assessments and follow-up actions for PDILI are provided in Section 10.6 (Appendix 6). 
7.1.1.1 
Follow-up evaluation 
Potential drug-induced liver injury events require follow-up monitoring as described in 
Table 10-3. Monitoring should continue until liver chemistry values normalize, stabilize, or 
return to Baseline. Determination of stabilization is at the discretion of the Investigator in 
consultation with the hepatologist (as applicable) and Medical Monitor and UCB Study 
Physician, as needed. 
7.1.2 
Clinical laboratory criteria 
Study participants should be monitored for absolute neutrophil count and/or absolute lymphocyte 
count as described in Section 7.1. 
7.1.3 
Temporary discontinuation of IMP 
The Investigator should not deviate from the protocol. However, the Investigator should take any 
measure necessary in deviation from, or not defined by, the protocol in order to protect clinical 
study participants from any immediate hazard to their health and safety. In this case, this action 
should be taken immediately, without prior notification of the regulatory authority, IRB/IEC, or 
Sponsor. 
After implementation of such measure, the Investigator must notify the CPM of the Sponsor 
within 24 hours and follow any local regulatory requirements. 
Any study participant who develops a clinically important infection or recurrent infection not 
responsive to standard therapy during the study must discontinue IMP until resolution of the 
infection. The Investigator should use clinical judgement in deciding whether the study 
participant should restart IMP and should contact the Medical Monitor and UCB Study Physician 
to confirm the study participant’s suitability for continued participation in the study. 
7.1.4 
IMP restart/rechallenge 
The criteria for IMP restart/rechallenge are described in Section 10.6.2.1. 
7.2 
Participant discontinuation/withdrawal from the study 
If a study participant is unable to attend a visit due to the coronavirus disease 2019 (COVID-19) 
pandemic, study-specific contingencies will be followed (Section 9.5), and the study participant 
should not be withdrawn. 
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Study participants are free to withdraw from the study at any time, without prejudice to their 
continued care. 
A study participant should be withdrawn from the study and will be encouraged to come back for 
the SFU Visit 17 weeks after final dose of IMP if the study participant withdraws his/her consent 
or the Sponsor or a regulatory agency requests withdrawal of the study participant. 
A study participant may withdraw from the study at any time at his/her own request or may be 
withdrawn at any time at the discretion of the Investigator for safety, behavioral, compliance, or 
administrative reasons. 
If a study participant withdraws consent for disclosure of future information, the Sponsor may 
retain and continue to use any data collected before such a withdrawal of consent. 
If a study participant withdraws from the study, he/she may request destruction of any samples 
taken and not tested, and the Investigator must document this in the site study records. 
See the SoA (Table 1-1) for data to be collected at the time of study discontinuation and 
follow-up and for any further evaluations that need to be completed. 
Refer to Section 7.1 for additional study participant discontinuation/withdrawal criteria. 
7.3 
Lost to follow up 
A study participant will be considered lost to follow up if he/she repeatedly fails to return for 
scheduled visits and is unable to be contacted by the study site. 
The following actions must be taken if a study participant fails to return to the clinic for a 
required study visit: 
• The site must attempt to contact the study participant and reschedule the missed visit as soon 
as possible, counsel the study participant on the importance of maintaining the assigned visit 
schedule, and ascertain whether or not the study participant wishes to and/or should continue 
in the study. 
• Before a study participant is deemed lost to follow up, the Investigator or designee must 
make every effort to regain contact with the study participant (≥1 phone call and 1 written 
message to the study participant) and document his/her effort (date and summary of the 
phone call and copy of the written message in the source documents) to complete the final 
evaluation. All results of these evaluations and observations, together with a narrative 
description of the reason(s) for removing the study participant, must be recorded in the 
source documents. The eCRF must document the primary reason for withdrawal. 
Should the study participant continue to be unreachable, he/she will be considered to have 
withdrawn from the study with a primary reason of lost to follow up documented in the eCRF. 
8 
STUDY ASSESSMENTS AND PROCEDURES 
Study procedures and their timing are summarized in the SoA (Table 1-1). 
Protocol waivers or exemptions are not allowed. 
Immediate safety concerns should be discussed with the Sponsor immediately upon occurrence 
or awareness to determine if the study participant should continue or discontinue IMP. 
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Adherence to the study design requirements, including those specified in the SoA (Table 1-1), is 
essential and required for study conduct. 
All screening evaluations must be completed and reviewed to confirm that potential study 
participants meet all eligibility criteria at the Baseline Visit for randomization. The Investigator 
will maintain a screening log to record details of all study participants screened and to confirm 
eligibility or record reasons for screening failure, as applicable. 
Procedures conducted as part of the study participant’s routine clinical management (eg, chest 
x-ray and computed axial tomography [CT] scan) and obtained before signing of the ICF may be 
utilized for Screening or Baseline purposes provided the procedures meet the protocol-specified 
criteria and were performed within the time frame defined in the SoA (Table 1-1). 
Repeat or unscheduled samples may be taken for safety reasons or for technical issues with the 
samples. 
Some study-specific investigations may not be possible to conduct according to the study 
protocol during a pandemic or other exceptional circumstances (eg, hurricanes) due to the need 
to implement safety measures and guidance from regulatory authorities. In such a situation, 
which may be accompanied by local or global containment or other measures, sites may need to 
prohibit access to study participants and study-related personnel. Study participants’ visits to the 
study site may be replaced by contingency measures. These measures are primarily established to 
ensure the continued safety of study participants during the course of the study and to maintain 
the study participants’ treatment schedules, if the Investigator considers it appropriate. The 
contingency measures will be described in a contingency plan which will be maintained by UCB 
for the respective study. The contingency measures are shared with the Investigator and the 
respective study-related personnel as soon as there are indications that it is necessary to 
implement any of the measures. 
8.1 
Efficacy assessments 
8.1.1 
PASI 
The PASI is the most commonly used and validated assessment for grading the severity of PSO 
in clinical studies (Feldman, 2004). The PASI quantifies the severity and extent of the disease 
and weighs these with the percentage of BSA involvement. The PASI will be completed by the 
Investigator electronically at the visits specified in the SoA (Table 1-1). 
The percent area of involvement (BSA%) will be estimated across 4 body areas: head, upper 
extremities, trunk, and lower extremities. Assessors will enter the degree of involvement for a 
given region on a scale of 0 to 6 (0=none; 1=1% to <10% affected; 2=10% to <30% affected; 
3=30% to <50% affected; 4=50% to <70% affected; 5=70% to <90% affected; 6=90% to 100% 
affected) (Table 8-1). 
The Investigator will assess the average redness, thickness, and scaliness of lesions in each body 
area (each on a 5-point scale: 0=none, 1=slight, 2=moderate, 3=marked, and 4=very marked). 
The PASI score ranges from 0 to 72, with a higher score indicating increased disease severity. 
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Table 8-1: 
Body areas for calculation of percent BSA for PASI 
Body area 
Details of area 
BSA 
Degree of 
involvement of 
body areaa 
Head 
Face, back of head 
10% 
0 to 6 
Upper extremities 
Left, right, upper lower, flexor 
surface, extensor surface 
20% 
0 to 6 
Trunk 
Front, back, groin 
30% 
0 to 6 
Lower extremities 
Left, right, upper lower, flexor 
surface, extensor surface, including 
buttocks 
40% 
0 to 6 
Total 
 
100% 
 
BSA=body surface area; PASI=Psoriasis Area and Severity Index 
a Where 0=none; 1=1% to <10% affected; 2=10% to <30% affected; 3=30% to <50% affected; 4=50% to <70% 
affected; 5=70% to <90% affected; 6=90% to 100% affected. 
The PASI75, PASI90, and PASI100 responses are based on ≥75%, ≥90%, and 
100% improvement in the PASI score, respectively. The total BSA affected by PSO will be 
entered as a percentage from 0 to 100. 
8.1.2 
IGA 
A static IGA for PSO will be used to assess disease severity in all study participants during the 
study. The IGA will be completed at the visits specified in the SoA (Table 1-1). 
The Investigator will assess the overall severity of PSO using the 5-point scale presented in 
Table 8-2. 
Table 8-2: 
Five-point IGA 
Score 
Short descriptor 
Detailed descriptor 
0 
Clear 
No signs of PSO; post-inflammatory hyperpigmentation may be present 
1 
Almost clear 
No thickening; normal to pink coloration; no to minimal focal scaling 
2 
Mild 
Just detectable to mild thickening; pink to light red coloration; 
predominately fine scaling 
3 
Moderate 
Clearly distinguishable to moderate thickening; dull to bright red, 
moderate scaling 
4 
Severe 
Severe thickening with hard edges; bright to deep dark red coloration; 
severe/coarse scaling covering almost all or all lesions 
IGA=Investigator’s Global Assessment; PSO=psoriasis 
8.1.3 
Patient Symptom Diary (Psoriasis-Symptom and Impact Measure)  
UCB developed a new electronic patient-reported outcome (ePRO) measure that will be used to 
assess key symptoms relevant to study participants with moderate to severe plaque PSO. 
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The Patient Symptom Diary (PSD) (Psoriasis-Symptom and Impact Measure [P-SIM]) consists 
of 14 items, measuring the following PSO-related signs, symptoms, and functional impacts: 
 
. Each item is assessed for severity/impact level 
on a 0 to 10 scale, where 0 means no symptoms or impact and 10 means very severe symptoms 
or worst impact. The PSD (P-SIM) will be assessed at the clinic during scheduled study visits as 
specified in the SoA (Table 1-1). 
8.1.4 
Scalp IGA 
A static IGA for scalp PSO will be used to assess disease severity on the scalp. Scalp lesions will 
be assessed in terms of clinical signs of redness, thickness, and scaliness using the 5-point scale 
presented in Table 8-3. 
The scalp IGA will be assessed for all study participants at Baseline. The scalp IGA will be 
completed by the Investigator electronically. Only study participants with a scalp IGA score >0 
at Baseline will have the scalp IGA assessed at later visits as specified in the SoA (Table 1-1). 
Table 8-3: 
Scalp IGA 
Score 
Short descriptor 
Detailed descriptor 
0 
Clear 
Scalp has no signs of PSO; post-inflammatory hyperpigmentation may 
be present 
1 
Almost Clear 
Scalp has no thickening; normal to pink coloration; no to minimal focal 
scaling 
2 
Mild 
Scalp has just detectable to mild thickening; pink to light red 
coloration; predominately fine scaling 
3 
Moderate 
Scalp has clearly distinguishable to moderate thickening; dull to bright 
red, moderate scaling 
4 
Severe 
Scalp has severe thickening with hard edges; bright to deep dark red 
coloration; severe/coarse scaling covering almost all or all lesions 
IGA=Investigator’s Global Assessment; PSO=psoriasis; scalp IGA=scalp-specific IGA 
8.1.5 
Dermatology Life Quality Index 
The Dermatology Life Quality Index (DLQI) is a questionnaire designed for use in adult study 
participants with PSO. The DLQI is a skin disease-specific questionnaire aimed at the evaluation 
of how symptoms and treatment affect study participants’ health-related quality of life (QoL). 
This instrument asks study participants about symptoms and feelings, daily activities, leisure, 
work and school, personal relationships, and treatment. It has been shown to be valid and 
reproducible in study participants with PSO. The DLQI score ranges from 0 to 30, with higher 
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scores indicating lower health-related QoL. A 4-point change in the DLQI score (DLQI 
response) has been reported to be meaningful for the study participant (within-participant 
minimal important difference), while a DLQI absolute score of 0 or 1 indicates no or small 
impact of the disease on health-related QoL (Basra et al, 2015; Hongbo et al, 2005). 
Study participants will be asked to complete the DLQI at the visits specified in the 
SoA (Table 1-1). 
The DLQI should be completed in a quiet place prior to any discussion regarding study-related 
issues, disease status, or treatment effect with the Investigator/site staff, and prior to any 
procedures. 
8.2 
Safety assessments 
8.2.1 
Clinical safety laboratory assessments 
All protocol-required laboratory assessments, as defined in Section 10.2 (Appendix 2) must be 
conducted in accordance with the laboratory manual and the SoA (Table 1-1). See Section 10.2 
and the SoA for the list, timing, and frequency of clinical laboratory tests to be performed. Blood 
samples will be collected prior to dosing for measurement of hematology and biochemistry 
laboratory measurements as well as interferon-gamma release assay (IGRA) assessments 
(see Section 8.2.5.3.4) as specified in the SoA (Table 1-1). 
The Investigator must review the laboratory report, document this review, and record any 
clinically significant changes occurring during the study in the AE section of the eCRF. The 
laboratory reports must be filed with the source documents. Clinically significant abnormal 
laboratory findings are those which are not associated with the underlying disease, unless judged 
by the Investigator to be more severe than expected for the study participant's condition. 
All laboratory tests with values considered clinically significantly abnormal during participation 
in the study or within 17 weeks after the final dose of IMP should be repeated until the values 
return to normal or Baseline or are no longer considered clinically significant by the Investigator 
or Medical Monitor. If such values do not return to normal/Baseline within a period of time 
judged reasonable by the Investigator, the etiology should be identified and the Sponsor notified. 
If laboratory values from nonprotocol-specified laboratory assessments performed at the 
institution’s local laboratory require a change in study participant management or are considered 
clinically significant by the Investigator (eg, SAE or AE or dose modification), then the results 
must be recorded in the eCRF. 
8.2.2 
Vital signs 
Vital signs will be collected at every visit and will include systolic and diastolic blood 
pressure (BP), pulse rate, and body temperature (oral, axillary, or otic). Study participants should 
be sitting for 5 minutes before and during vital signs assessments. 
Vital signs should be assessed prior to IMP administration and prior to any blood collection. 
8.2.3 
Physical examination 
The physical examination will include general appearance; ear, nose, and throat; eyes, hair, and 
skin; and assessments of the respiratory, CV, gastrointestinal (GI), musculoskeletal, hepatic, and 
neurological (including limb reflexes) systems; and mental status. All physical examinations will 
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also include evaluation of signs and symptoms of active TB and risk for exposure to TB 
(Section 8.2.5.3). Findings considered clinically significant changes since the physical 
examination at the Screening Visit will be recorded as AEs. 
Investigators should pay special attention to clinical signs related to previous serious illnesses. 
8.2.4 
12-lead electrocardiogram 
Twelve-lead standard electrocardiograms (ECGs) will be recorded at the Screening Visit. Full 
details of ECG recording will be provided in the ECG Manual. 
8.2.5 
Assessment and management of TB and TB risk factors 
All study participants will be assessed for TB through physical examination for signs and 
symptoms of TB (Section 8.2.5.3.1), laboratory testing (Section 8.2.1), chest x-ray/CT scan 
(Section 8.2.5.3.2), and TB questionnaire (Section 8.2.5.3.3). 
8.2.5.1 
Definitions 
Study participants with known active TB disease, at high risk of acquiring TB infection, or with 
untreated LTBI (ie, pending anti-TB prophylactic course) or current or history of NTMB 
infection are excluded from the study. 
a. Known TB infection whether present or past is defined as: 
• Active TB disease or clinical signs and symptoms strongly suggestive of TB (pulmonary 
or extrapulmonary) 
• History of active TB disease involving any organ system or findings in other organ 
systems consistent with TB, unless adequately treated and proven to be fully recovered 
upon consult with a TB specialist 
• Any evidence by radiography or other imaging modalities consistent with previously 
active TB disease that is not reported in the study participant's medical history 
b. High risk of acquiring TB infection is defined as: 
• Known close exposure (eg, sleeping in the same room) to another person with active TB 
infection within 3 months prior to Screening 
• Time spent within 3 months prior to Screening in a health care delivery setting or 
institution where individuals infected with TB are housed or where the risk of 
transmission of infection is high 
c. Latent TB infection is defined as an infection by Mycobacterium tuberculosis with: 
• A positive IGRA (or 2 indeterminate IGRAs), AND 
• Chest imaging (or other imaging) negative for TB infection, AND 
• Absence of signs, symptoms (eg, evidence of organ-specific involvement), or physical 
findings suggestive of TB infection. 
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d. Pulmonary NTMB infection is defined as a group of lung or extrapulmonary infections 
caused by mycobacteria different from Mycobacterium tuberculosis (M. tuberculosis) 
infections. 
8.2.5.2 
Assessments at Screening 
At Screening, all study participants will have an IGRA test (QuantiFERON Gold Plus TB test is 
recommended), a chest x-ray (unless already performed within 3 months of Screening; CT scan 
of the chest at Screening or within 3 months prior to Screening is acceptable, if available), and 
examination for signs and symptoms of TB. In addition, each study participant will complete a 
TB questionnaire directed at potential exposure to TB and symptoms of TB. 
Study participants diagnosed with active TB during Screening will be excluded from the study. 
Study participants with LTBI diagnosed during Screening must complete a full course of 
prophylaxis and can be rescreened after completion of 4 weeks of prophylaxis prior to the first 
dose of IMP, as described in the exclusion criteria (Section 5.2). 
A decision tree for IGRA TB results at Screening, including study participant eligibility, 
retesting requirements, and treatment requirements at Screening, is shown in Figure 8-1. 
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Figure 8-1: Decision tree for IGRA TB results at Screening 
 
IGRA=interferon-gamma release assay; IMP=investigational medicinal product; LTBI=latent tuberculosis infection; 
TB=tuberculosis 
a Interferon-gamma release assay retest must be done during the protocol-defined Screening window. 
b Study participants with LTBI diagnosed during Screening must complete a course of prophylaxis. Study 
participants can be rescreened after completion of 4 weeks of prophylaxis prior to the first dose of IMP. 
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8.2.5.3 
Assessment and reporting of TB and TB risk factors during the study 
8.2.5.3.1 
Physical examination 
The Investigator should consider all potential sites of infection when assessing for TB during the 
physical examination and other evaluations, and based on the study participant’s medical or 
social history. 
The most common primary focus of TB is the lung. Other sites may include the GI system, 
bone/joints, lymph glands, and meninges. However, in immune-compromised patients, study 
participants, and/or patients treated with biologics, especially TNF inhibitors, extrapulmonary 
manifestations of TB are common compared to the normal population. 
Some common symptoms that the study participant may present are dependent on the primary 
focus of infection and may include cough, blood in sputum, night sweats, lymphadenitis, joint 
pain/swelling, spinal deformity, headache/confusion, and abdominal pain (mimicking IBD). 
Unusual presentations should always be considered. 
8.2.5.3.2 
Chest x-ray/CT scan for TB 
Chest radiographic imaging is performed at Screening, and results must be available at Baseline 
before first IMP administration unless a chest x-ray or CT scan is available within 3 months prior 
to Screening. 
Additional chest x-rays or other imaging tests should be performed when positive signs and 
symptoms indicate pulmonary infection, including potential TB infection, or when close 
exposure to persons with TB is documented. 
8.2.5.3.3 
Tuberculosis questionnaire 
The questionnaire “Evaluation of signs and symptoms of tuberculosis” should be used as a 
source document. The questionnaire will be completed as described in the SoA (Table 1-1). The 
questionnaire will assist with the identification of study participants who may require therapy for 
TB. 
A study participant who answers “Yes” at Screening to the question 
 
 
 should not be 
allowed into the study pending further assessments (including TB specialist consult). A “Yes” 
response to any of the questions in the TB questionnaire during the study may trigger further 
assessment to determine if the study participant has either LTBI and must receive 
TB prophylactic therapy prior to continuing IMP, or active TB infection and must be withdrawn 
from the study. 
8.2.5.3.4 
Interferon-gamma release assay test conversion 
The IGRA is a whole blood testing methodology for diagnosing M. tuberculosis infection. It has 
become the gold standard, but it does not help in differentiating LTBI from active TB disease. 
Tuberculosis test conversion is defined as a positive or indeterminate (and confirmed 
indeterminate on repeat) IGRA result for the current test when previous IGRA test results were 
negative. All study participants with positive or indeterminate IGRA test results must 
immediately stop IMP administration. In case of an IGRA test conversion, the study participant 
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must be considered as having either a suspected new latent or an active TB infection and be 
promptly referred to an appropriate specialist (eg, pulmonologist, infectious disease specialist) 
for further evaluation. Where medically relevant, additional assessments (eg, blood tests or 
IGRA, chest x-rays, or other imaging) should be performed and documented. Such conversions 
should be reported as AEs as described in the protocol. The AE term should be updated with the 
final diagnosis once available. 
8.2.5.3.5 
Latent TB 
If evaluation by the appropriate specialist diagnoses a new LTBI, a TB prophylactic therapy in 
accordance with applicable clinical guidelines should be immediately initiated. 
Study participants who initiate treatment for LTBI during the Screening Period must repeat 
initial screening laboratory parameters, all physical examinations, and questionnaires prior to 
randomization in the study and must continue the full course of TB prophylactic therapy. Study 
participants can be rescreened after completion of 4 weeks of prophylaxis prior to the first dose 
of IMP. 
If no TB prophylactic therapy is initiated for the newly diagnosed LTBI during Screening, the 
study participant must not be enrolled into the study. Every related action should be discussed in 
advance with the Medical Monitor. 
Any study participant who develops LTBI during the study must discontinue further 
administration of IMP, and a PEOT Visit must be scheduled as soon as possible, but not later 
than the next regular visit. The study participant must be permanently withdrawn if the study 
participant is diagnosed with LTBI with no initiation of prophylactic treatment, prematurely 
discontinues prophylactic treatment, or, in the opinion of the Investigator or Sponsor, is 
noncompliant with prophylactic TB therapy. Once withdrawn, the PEOT Visit must be scheduled 
as soon as possible, and the study participant should be encouraged to keep the SFU Visit. Latent 
TB infection must be reported as an AE. Follow-up reports should be completed as described in 
Section 10.3 (Appendix 3) until the LTBI resolves. 
8.2.5.3.6 
Active TB or NTMB infection 
Study participants who develop active TB or NTMB infection during the study must be 
withdrawn from the study. The study participant must be immediately permanently discontinued 
from IMP, and a PEOT Visit must be scheduled as soon as possible, but no later than the next 
scheduled visit. The study participant should be encouraged to keep the SFU Visit as specified 
by the protocol. Treatment for active TB or NTMB should be started immediately. 
Confirmed active TB is always considered an SAE. UCB’s process requires that these must be 
captured on an SAE Report Form and provided to the Sponsor in accordance with SAE reporting 
requirements (Section 10.3 [Appendix 3]). Follow-up reports should be completed 
as per protocol requirement until the TB infection resolves. 
8.2.5.3.7 
Tuberculosis management of LTBI, active TB, or other NTMB 
infection identified during study 
During the study, study participants who develop evidence of LTBI, active TB, or NTMB 
infection must immediately stop further administration of IMP and will be referred to a 
TB specialist (pulmonologist or infectious disease specialist) for further evaluation. Study 
participants diagnosed with active TB or LTBI should receive appropriate TB or prophylaxis 
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therapy. The study participant should be transferred to the care of his/her physician and managed 
according to the standard of care. 
Study participants identified as having active TB during the study must be withdrawn and 
scheduled to return for the PEOT Visit as soon as possible, but no later than the next scheduled 
study visit, and complete all PEOT assessments. The study participant should be encouraged to 
complete a SFU Visit after the final dose of IMP. 
If infection with NTMB is identified during the study, the same procedure as for active TB 
acquired during the study and compliant TB treatment shall be followed. 
Additional details on TB detection and management are provided in the UCB TB Detection 
Procedure Guideline. 
8.3 
Adverse events and SAEs 
Adverse events will be reported by the study participant. 
The Investigator and any designees are responsible for detecting, documenting, and recording 
events that meet the definition of an AE or SAE and remain responsible for following up AEs 
that are serious, considered related to the IMP or study procedures, or that caused the study 
participant to discontinue the IMP or the study (Section 7). 
8.3.1 
Time period and frequency for collecting AE and SAE information 
All AEs and SAEs will be collected from the signing of the ICF until the SFU Visit at the visits 
specified in the SoA (Table 1-1). 
In order to ensure complete safety data collection, all AEs occurring during the study (ie, after 
the signing of the ICF), including any pretreatment and posttreatment periods required by the 
protocol, must be reported in the eCRF even if no IMP was taken but specific study procedures 
were conducted. This includes all AEs not present prior to the Screening Visit and all AEs that 
recurred or worsened after the Screening Visit. 
All SAEs will be recorded and reported to the Sponsor or designee within 24 hours, as indicated 
in Section 10.3 (Appendix 3). The Investigator will submit any updated SAE data to the Sponsor 
within 24 hours of it being available. 
The Investigator is specifically requested to collect and report to UCB (or its representative) any 
SAEs (even if the Investigator is certain that they are in no way associated with the IMP), up to 
17 weeks from the final dose of IMP for each study participant and to also inform study 
participants of the need to inform the Investigator of any SAE within this period. Serious AEs 
that the Investigator thinks may be associated with the IMP must be reported to UCB regardless 
of the time between the event and the end of the study. 
The method of recording, evaluating, and assessing causality of AEs and SAEs and the 
procedures for completing and transmitting SAE reports are provided in Section 10.3 
(Appendix 3). 
8.3.2 
Method of detecting AEs and SAEs 
Care will be taken not to introduce bias when detecting AEs and/or SAEs. Open-ended and 
non-leading verbal questioning of the study participant is the preferred method to inquire about 
AE occurrences. 
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8.3.3 
Follow up of AEs and SAEs 
After the initial AE/SAE report, the Investigator is required to proactively follow each study 
participant at subsequent visits/contacts. All SAEs will be followed until resolution, stabilization, 
the Investigator determines that it is no longer clinically significant, the event is otherwise 
explained, or the study participant is lost to follow up (as defined in Section 7.3). Further details 
of follow-up procedures are provided in Section 10.3 (Appendix 3). 
8.3.4 
Regulatory reporting requirements for SAEs 
Prompt notification by the Investigator to the Sponsor of a SAE is essential so that legal 
obligations and ethical responsibilities towards the safety of study participants and the safety of 
an IMP under clinical investigation are met. 
The Sponsor has a legal responsibility to notify both the local regulatory authority and other 
regulatory agencies about the safety of IMP under clinical investigation. The Sponsor will 
comply with Chinese regulatory requirements relating to safety reporting to the regulatory 
authority, IRB/IEC, and Investigator. 
Investigator safety reports must be prepared for suspected unexpected serious adverse reactions 
according to local regulatory requirements and Sponsor policy and forwarded to Investigators as 
necessary. 
An Investigator who receives an Investigator safety report describing a SAE or other specific 
safety information (eg, summary or listing of SAEs) from the Sponsor will review and then file it 
along with the IB and will notify the IRB/IEC, if appropriate according to local requirements. 
8.3.5 
Pregnancy 
Details of all pregnancies in female study participants and female partners of male study 
participants will be collected after the start of IMP and until the SFU Visit. 
If a pregnancy is reported, the Investigator must immediately inform the Sponsor within 24 hours 
of receipt of the information and should follow the procedures outlined in 
Section 10.4 (Appendix 4). 
The female study participant should be discontinued from the IMP as soon as pregnancy is 
known (by positive pregnancy test), and the following should be completed: 
• The study participant should return for a PEOT visit. 
• The study participant should immediately stop the intake of IMP. 
• A SFU Visit should be scheduled 17 weeks after the study participant has discontinued IMP. 
Abnormal pregnancy outcomes (eg, spontaneous abortion, fetal death, stillbirth, congenital 
anomalies, ectopic pregnancy) are considered SAEs. 
8.3.6 
AEs of special interest 
An AE of special interest (AESI) is any AE that a regulatory authority has mandated be reported 
on an expedited basis, regardless of the seriousness, expectedness, or relatedness of the AE to the 
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administration of a UCB product/compound. For bimekizumab, the following event requires 
immediate reporting (within 24 hours regardless of seriousness) to UCB: 
• Hy’s Law 
− Potential Hy’s Law, defined as ALT or AST ≥3×ULN with coexisting total bilirubin 
≥2×ULN in the absence of ALP ≥2×ULN, with no alternative explanation for the 
biochemical abnormality (ie, without waiting for any additional etiologic investigations 
to have been concluded). Follow-up information should be reported if an alternative 
etiology is identified during investigation and monitoring of the study participant. 
8.3.7 
Other safety topics of interest 
Prespecified safety topics of interest for this study are as follows: infections (serious, 
opportunistic, fungal, and TB), neutropenia, hypersensitivity, injection site reactions, 
neuropsychiatric AEs (including SIB), major CV events, LFT changes/enzyme elevations, 
malignancies, and IBD. 
These safety topics of interest are based on findings from the bimekizumab clinical program to 
date, potential risks generally associated with biologic immunomodulators, or findings from 
other medicines with a related mechanism of action. There are no specific AE reporting 
requirements for these topics, however, special monitoring, additional data collection activities, 
and/or enhanced signal detection activities within UCB are in place. 
The reporting requirements for events relating to TB are as follows: 
• Interferon-gamma release assay test conversion, defined as a positive or indeterminate (and 
confirmed indeterminate on repeat) IGRA result for the current test when previous IGRA test 
results were negative, should be reported as an AE (Section 8.2.5.3.4). The AE term would 
need to be updated with final diagnosis once available. 
• Latent TB infection must be reported as an AE (Section 8.2.5.3.5). Follow-up reports should 
be completed as described in Section 10.3 (Appendix 3) until the LTBI resolves. 
• Confirmed active TB is always considered an SAE and must be captured on an SAE Report 
Form and provided to the Sponsor in accordance with SAE reporting requirements 
(Section 10.3 [Appendix 3]). Follow-up reports should be completed as described in 
Section 10.3 (Appendix 3) until the TB infection resolves (Section 8.2.5.3.6). 
8.3.8 
Anticipated SAEs 
Anticipated SAEs (ie, serious AEs that are anticipated to occur in the study population at some 
frequency that is independent of drug exposure) for this study are presented in Table 8-4. 
This list does not change the Investigator’s obligation to report all SAEs (including anticipated 
SAEs) as detailed in Section 10.3 (Appendix 3). 
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Table 8-4: 
Anticipated SAEs for study participants with moderate to severe 
plaque PSO 
MedDRA system organ class 
MedDRA preferred term 
Skin and subcutaneous tissue disorders 
Any psoriatic condition HLT 
Musculoskeletal and connective tissue disorders 
Psoriatic arthropathy 
HLT=high level term; MedDRA=Medical Dictionary for Regulatory Activities; PSO=psoriasis; SAE=serious 
adverse event 
Note: Exception: Listed events will not be regarded as anticipated SAEs if they are life threatening or if they 
result in the death of the study participant. 
8.3.9 
Medical device AEs and device deficiencies 
The device is used in this study for the purposes of IMP administration (Section 6.1.1). In order 
to fulfill regulatory reporting obligations worldwide, the Investigator is responsible for the 
detection and documentation of events meeting the definitions of incident or malfunction that 
occur during the study with such devices. 
Adverse events will be reported according to the ISO 14155:2020, while recognizing and 
following requirements, including reporting timelines specified in other specific laws, 
regulations, directives, standards and/or guidelines. 
The definition of an ADE, serious adverse device effect (SADE), and medical device deficiency 
can be found in Section 10.7 (Appendix 7). 
NOTE: Events fulfilling the definition of an AE/SAE will also follow the processes outlined in 
Section 8.3.3 and Section 10.3 (Appendix 3). 
8.3.9.1 
Time period for detecting medical device deficiencies 
Adverse device effects and device deficiencies will be detected, documented, and reported 
during all periods of the study in which the device is used. 
If the Investigator learns of any deficiency at any time after a study participant has been 
discharged from the study and such event(s) is considered reasonably related to a device 
provided for the study, the Investigator will promptly notify the Sponsor. 
The method of documenting device deficiency is provided in Section 10.7 (Appendix 7). 
8.3.9.2 
Follow up of ADEs and device deficiencies 
Follow up applies to all study participants, including those who discontinue IMP and/or the 
study. 
The Investigator is responsible for ensuring that follow up includes any supplemental 
investigations as indicated to elucidate the nature and/or causality of the deficiency. 
New or updated information will be recorded on the originally completed form with all changes 
signed and dated by the Investigator. 
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8.3.9.3 
Prompt reporting of ADEs and device deficiencies to Sponsor 
Adverse device effects and device deficiencies will be reported to the Sponsor within 24 hours 
after the Investigator determines that the event meets the protocol definition of an ADE or device 
deficiency. 
The Sponsor will be the contact for the receipt of ADE and device deficiency reports. The 
Adverse Event and Device Deficiency Report Form will be sent to the Sponsor. 
8.3.9.4 
Regulatory reporting requirements for ADEs and device deficiencies 
The Investigator will promptly report all ADEs and device deficiencies occurring with any 
medical device provided for use in the study to the Sponsor to fulfill the legal responsibility to 
notify appropriate regulatory authorities and other entities about certain safety information 
relating to devices being used in clinical studies. 
The Investigator, or responsible person according to local requirements (eg, the head of the 
medical institution), will comply with the applicable local regulatory requirements relating to the 
reporting of ADEs and device deficiencies to the IRB/IEC. 
8.4 
Safety signal detection 
Selected data from this study will be reviewed periodically to detect as early as possible any 
safety concern(s) related to the IMP so that Investigators, study participants, regulatory 
authorities, and IRBs/IECs will be informed appropriately and as early as possible. 
The UCB Study Physician or medically qualified designee/equivalent will conduct an ongoing 
review of SAEs and perform ongoing SAE reconciliations in collaboration with the Patient 
Safety (PS) representative. 
As appropriate for the stage of development and accumulated experience with the IMP, 
medically qualified personnel at UCB may identify additional safety measures (eg, AEs, vital 
signs, laboratory results) for which data will be periodically reviewed during the course of the 
study. 
8.5 
Treatment of overdose 
For this study, any dose of bimekizumab greater than that prescribed in the protocol (ie, 320mg) 
will be considered an overdose. Overdose events are only considered AEs or SAEs if there are 
associated clinical signs and symptoms or if the act of taking the excess IMP itself is an AE or 
SAE (eg, suicide attempt). 
UCB does not recommend specific treatment for an overdose. Any signs or symptoms of adverse 
reactions should be treated symptomatically as per standard care by the Investigator. 
In the event of an overdose, the Investigator should: 
1. Contact the Medical Monitor immediately 
2. Closely monitor the study participant for any AE/SAE and laboratory abnormalities until 
bimekizumab can no longer be detected systemically (≥90 days) 
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3. Obtain a plasma sample for PK analysis as soon as possible after the final dose of IMP if 
requested by the Medical Monitor (determined on a case-by-case basis) 
4. Document the quantity of the excess dose as well as the duration of the overdose in the eCRF 
Decisions regarding dose interruptions or modifications will be made by the Investigator in 
consultation with the Medical Monitor based on the clinical evaluation of the study participant. 
8.6 
Pharmacokinetics 
Blood samples will be collected prior to dosing for measurement of plasma concentrations of 
bimekizumab at the visits specified in the SoA (Table 1-1). 
Instructions for the collection and handling of biological samples will be provided by the 
Sponsor. The actual date and time (24-hour clock time) of each sample will be recorded. 
Samples will be used to evaluate the PK of bimekizumab. Samples collected for analyses of 
bimekizumab plasma concentration may also be used to evaluate safety or efficacy aspects 
related to concerns arising during or after the study. 
Study participant confidentiality will be maintained. At visits during which blood samples for the 
determination of plasma concentrations of bimekizumab will be taken, 1 sample of sufficient 
volume can be used. 
Drug concentration information that may unblind the study will not be reported to any blinded 
study personnel as long as the study remains blinded. 
8.7 
Biomarkers 
Biomarkers are not evaluated in this study. 
8.8 
Immunogenicity assessments 
Antibodies to bimekizumab will be evaluated in plasma samples collected from all study 
participants at the visits specified in the SoA (Table 1-1). Additionally, plasma samples should 
also be collected at the final visit from study participants who discontinue IMP or withdraw from 
the study. These samples will be tested by the Sponsor or Sponsor's designee. 
A tier-based approach will be used, consisting of consecutive screening, confirmatory, and 
titration methods. Plasma samples will be screened for antibodies binding to bimekizumab, and 
the titer of confirmed positive samples will be reported. Other analyses may be performed to 
verify the stability of antibodies to bimekizumab and/or further characterize the immunogenicity 
of bimekizumab. 
The detection and characterization of antibodies to bimekizumab will be performed using 
validated assay methods by or under the supervision of the Sponsor. The procedures for sample 
analysis and the relevant validation results will be described in a separate bioanalytical report. 
All samples collected for detection of antibodies to IMP will also be evaluated for bimekizumab 
plasma concentration to enable interpretation of the antibody data. Confirmed positive antibody 
samples will be further characterized for their ability to neutralize the activity of 
bimekizumab. Samples may be stored for a maximum of 20 years (or according to local 
regulations) following the last study participant’s last visit for the study at a facility selected by 
the Sponsor, to enable further analysis of immune responses to bimekizumab. 
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8.9 
Medical resource utilization and health economics 
Health economics/medical resource utilization and health economics parameters are not 
evaluated in this study. 
9 
STATISTICAL CONSIDERATIONS 
A description of statistical methods is provided below. Statistical methods will be described in 
more detail in the Statistical Analysis Plan (SAP). 
9.1 
Definition of analysis sets 
The Enrolled Set (ES) will consist of all study participants who have given informed consent. 
The Randomized Set (RS) will consist of all randomized study participants. 
The Safety Set (SS) will consist of all study participants who receive ≥1 dose of IMP. 
The Full Analysis Set (FAS) will consist of all randomized study participants who receive 
≥1 dose of IMP and have a valid measurement for each of the co-primary efficacy endpoints at 
Baseline. 
The Active Medication Set (AMS) will consist of all study participants who receive ≥1 dose of 
active IMP (bimekizumab). 
The Per-Protocol Set (PPS) will consist of all study participants in the RS who have no important 
protocol deviations affecting the co-primary efficacy endpoints. Important protocol deviations 
will be predefined, and study participants with important protocol deviations will be evaluated 
during ongoing data cleaning meetings prior to unblinding of the data. 
The Pharmacokinetics Per-Protocol Set (PK-PPS) will consist of all randomized study 
participants who receive ≥1 dose of IMP and provide ≥1 quantifiable plasma concentration 
postdose without important protocol deviations that would affect the concentration. 
9.2 
General statistical considerations 
Summary statistics will consist of frequency tables for categorical variables. For continuous 
variables, summary statistics will consist of the number of available observations, arithmetic 
mean, standard deviation, median, minimum, and maximum, unless stated otherwise. 
All analyses will be performed using SAS® version 9.3 or later (SAS Institute, Cary, NC, US). 
The statistical analysis of the co-primary efficacy endpoints will be performed using a 
Type I error rate at a 2-sided alpha level of 0.05. 
9.2.1 
Multiplicity 
The statistical analysis of the co-primary efficacy endpoints and key secondary endpoints will 
account for multiplicity and control the familywise Type I error rate at a 2-sided alpha level 
of 0.05 by using a fixed sequence testing procedure. 
The hypotheses (H1, H2, H3, H4) comparing bimekizumab versus placebo will be tested 
at a 2-sided alpha level of 0.05. 
The first 2 hypotheses (H1 and H2) will separately test whether bimekizumab is superior to 
placebo for PASI90 response and IGA 0/1 response at Week 16. These are the hypothesis tests 
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corresponding to the co-primary endpoints. If both null hypotheses are rejected at a 2-sided alpha 
level of 0.05, that alpha will be passed to the next test in the sequence, allowing the testing 
procedure to proceed. 
The hypotheses associated with the subsequent tests (H3 and H4) are for the 2 key secondary 
efficacy endpoints and are based on testing for superiority relative to placebo. See Table 9-1 for 
details on this procedure. 
Table 9-1: 
Sequence of hypothesis testing 
Hypothesis 
Test 
H1 and H2 
PASI90 and IGA 0/1 response at Week 16 
H3 
PASI75 response at Week 4 
H4 
PASI100 response at Week 16 
H=hypothesis; IGA 0/1=Investigator’s Global Assessment response clear (0) or almost clear (1) with ≥2-category 
improvement relative to Baseline; PASI=Psoriasis Area and Severity Index; PASI75/90/100=75% or 
greater/90% or greater/100% improvement from Baseline in the PASI score 
9.3 
Planned efficacy/outcome analyses 
9.3.1 
Analysis of the primary efficacy/primary endpoints 
The co-primary efficacy endpoints for this study will be PASI90 response and IGA 0/1 response 
at Week 16. 
The co-primary efficacy endpoints will be analyzed for all study participants in the RS. 
The co-primary efficacy endpoints will be derived as follows: 
• PASI90 responder at Week 16: PASI score at Week 16 has improved by ≥90% from 
Baseline, and the study participant has not discontinued IMP prior to Week 16. 
• IGA 0/1 responder at Week 16: IGA score at Week 16 is 0 or 1 (clear or almost clear) with 
≥2-category improvement from Baseline in the IGA score, and the study participant has not 
discontinued IMP prior to Week 16. 
The evaluation of superiority (bimekizumab versus placebo treatment comparison) will be based 
on the Cochran-Mantel-Haenszel (CMH) test. Treatment comparisons will be made based on the 
CMH test using the p-value for the general association. Odds ratios and 95% confidence 
intervals (CIs) based on the CMH method will also be presented. 
Nonresponder imputation (NRI) will be used to account for missing data in the primary analysis. 
Specifically, any study participant who withdraws from IMP prior to Week 16 or who has 
missing data for the co-primary efficacy variables at the Week 16 time point will be considered a 
nonresponder. Based on previous studies of biologics in study participants with moderate to 
severe chronic plaque PSO, it is expected that the number of study participants who discontinue 
prior to Week 16 will be low. For the small percentage of study participants for whom primary 
endpoint data are unavailable at Week 16, this lack of data is suggestive of an ineffective IMP, 
thereby supporting the imputation of nonresponse. Therefore, NRI is considered an appropriate 
method for handling missing data since achieving the clinical response and making it through 
16 weeks of IMP are both critical components of the primary outcome. 
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9.3.1.1 
Sensitivity analyses 
The primary efficacy analysis described in Section 9.3.1 will be repeated using the FAS and PPS 
with the NRI method similar to the primary analysis (Section 9.3.1). Observed case summaries 
(excluding study participants with missing PASI/IGA data at Week 16) will also be provided as a 
sensitivity analysis to the primary analysis method. 
Additional sensitivity analyses of the co-primary endpoints for handling missing data will also be 
performed and are described in detail in Section 9.6. 
9.3.2 
Secondary efficacy endpoint analyses 
The secondary efficacy endpoints will be analyzed for all study participants in the RS using the 
NRI method similar to the primary analysis (Section 9.3.1). 
For the binary secondary efficacy endpoints assessing the superiority of bimekizumab versus 
placebo, the CMH test as specified for the primary analysis will be implemented (Section 9.3.1). 
For all secondary efficacy endpoints, observed case summaries will also be presented. 
9.3.2.1 
Key secondary efficacy endpoint analyses 
The binary key secondary efficacy endpoints will be derived as follows: 
• PASI75 responder at Week 4: PASI score at Week 4 has improved by ≥75% from Baseline, 
and the study participant has not discontinued IMP prior to Week 4. 
• PASI100 responder at Week 16: PASI score at Week 16 has improved by 100% from 
Baseline (ie, PASI complete response), and the study participant has not discontinued IMP 
prior to Week 16. 
The key secondary efficacy endpoints (PASI75 response at Week 4 and PASI100 response at 
Week 16) will be analyzed using the same method as for the co-primary endpoints by using RS 
and NRI method (Section 9.3.1). In addition, analyses will be repeated using the FAS and the 
NRI method. Observed case summaries will also be provided as a sensitivity analysis. Missing 
data for these variables will also be imputed using multiple imputation (MI) similar to the 
sensitivity analyses for the co-primary endpoints. Further details on multiple imputation are 
described in Section 9.6.  
9.3.2.2 
Additional secondary efficacy endpoint analyses 
The additional secondary efficacy endpoints will be derived as follows: 
• PSD (P-SIM) responder for itch at Week 16: Itch score has improved (decreased) by 
≥4 points from Baseline to Week 16, and the study participant has not discontinued IMP 
prior to Week 16. This will be assessed only in study participants with a Baseline itch score 
≥4. 
• PSD (P-SIM) responder for pain at Week 16: Pain score has improved (decreased) by 
≥4 points from Baseline to Week 16, and the study participant has not discontinued IMP 
prior to Week 16. This will be assessed only in study participants with a Baseline pain score 
≥4. 
• PSD (P-SIM) responder for scaling at Week 16: Scaling score has improved (decreased) by 
≥4 points from Baseline to Week 16, and the study participant has not discontinued IMP 
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prior to Week 16. This will be assessed only in study participants with a Baseline scaling 
score ≥4. 
9.3.3 
Tertiary efficacy endpoint analyses 
The tertiary efficacy endpoints in the Initial Treatment Period and the Overall Treatment Period 
(Initial Treatment Period+Maintenance Treatment Period) will be analyzed for all study 
participants in the RS. 
Binary (responder) endpoints will be summarized using frequency tables by treatment group for 
each visit. Continuous endpoints will be summarized using descriptive statistics by treatment 
group for each visit. 
Time to PASI75/90/100 response during the Initial Treatment Period will be estimated and 
presented using the Kaplan-Meier product-limit method for each treatment group. Time to a 
given response will be defined as the length in days from the first dose of IMP until the first date 
when the response is achieved. Study participants who discontinue IMP prior to achieving a 
response will be censored at the date of IMP discontinuation. Study participants who reach the 
Week 16 visit without achieving the given PASI response will be censored at the date of the 
Week 16 visit. Study participants will be censored at Baseline (Day 0) if there is no Baseline 
PASI assessment or no post-Baseline PASI assessment. The median time to response, including 
the 2-sided 95% CI, will be calculated for each treatment group. Comparisons of bimekizumab 
versus placebo will be analyzed using a log-rank test. 
All binary tertiary efficacy endpoints will be summarized based on imputed data (NRI), unless 
otherwise stated in the SAP. In some cases, endpoints may also be summarized based on 
observed case data (ie, study participants with missing data or who have prematurely 
discontinued IMP are treated as missing). Should there be no missing data for a study endpoint, 
then only observed case data will be presented. Continuous variables will be summarized using 
descriptive statistics by treatment group for each visit based on observed case. 
9.4 
Planned safety and other analyses 
9.4.1 
Safety analyses 
Safety endpoints will be analyzed for all study participants in the SS. The AMS will be used for 
summaries of safety that include data from the Initial Treatment Period and/or 
Maintenance Treatment Period. Further details will be specified in the SAP. 
9.4.1.1 
AEs 
Adverse events will be coded according to the most recent Medical Dictionary for Regulatory 
Activities. Treatment-emergent AEs are defined as those AEs that have a start date on or 
following the first dose of IMP. 
The frequency of all TEAEs will be presented for each treatment group separately by SOC, 
high level term (HLT), and preferred term. The data will be displayed as number of study 
participants experiencing the TEAE, percentage of study participants, and number of TEAEs. 
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Additional tables will summarize TEAEs by severity and relationship to IMP, TEAEs leading to 
study discontinuation, serious TEAEs, deaths, and TEAEs categorized as safety topics of interest 
and AESIs. Definitions for categorizing TEAEs as safety topics of interest and AESIs will be 
provided in the SAP. 
If a TEAE occurs on the date of a study treatment switch, the event will be attributed to the 
original study treatment (the “preswitch” treatment). The only exceptions are for the following 
types of events, which will be attributed to the new study treatment: 
• Events that fulfill the anaphylaxis criteria for acute events (the criteria for acute anaphylaxis 
events will be provided in the SAP) 
• Events that fulfill the hypersensitivity reaction criteria (the algorithm for defining a 
hypersensitivity reaction will be provided in the SAP) 
• Events with an HLT of “Administration site reactions NEC” 
• Events with an HLT of “Injection site reactions” 
Further details of TEAE summaries will be provided in the SAP. 
Extent of exposure will be presented descriptively by treatment group. 
9.4.1.2 
Hematology/biochemistry 
Treatment-emergent markedly abnormal (TEMA) laboratory values are those that have an 
assessment date on or following first dose of IMP. 
Laboratory assessments will be analyzed by visit. Absolute values and changes from Baseline in 
each laboratory parameter will be presented descriptively for each treatment group. The 
incidence rate of TEMA laboratory values at the parameter level will also be presented 
descriptively for each treatment group. Definitions for markedly abnormal laboratory values will 
be provided in the SAP. 
9.4.1.3 
Vital signs 
Vital signs will be summarized by visit. Absolute values and change from Baseline in systolic 
and diastolic BP and pulse rate will be presented descriptively by visit for each treatment group. 
Markedly abnormal vital signs will be summarized. Definitions of markedly abnormal vital signs 
will be provided in the SAP. 
9.4.1.4 
Physical examination 
Clinically significant changes from Baseline in physical examination findings will be reported as 
AEs and included in the TEAE summarization described in Section 9.4.1.1. 
9.4.2 
PK and ADAb analyses 
Plasma bimekizumab concentrations will be summarized for the PK-PPS at each time point 
using descriptive statistics. In addition, PK model-based analyses may be performed and reported 
separately. 
Antidrug antibody data will be evaluated for each study participant in the SS, and rates of 
ADAb-positive study participants will be calculated. Neutralizing ADAb data will also be 
evaluated. Further details will be provided in the SAP. 
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9.5 
Handling of protocol deviations 
Important protocol deviations are deviations from the protocol which potentially could have a 
meaningful impact on study conduct or on the primary efficacy, key safety, or PK outcomes for 
an individual study participant. The criteria for identifying important protocol deviations will be 
defined within the appropriate protocol-specific document at study start. Important protocol 
deviations will be reviewed as part of the ongoing data cleaning process, and all important 
deviations will be identified and documented prior to unblinding to confirm exclusion from 
analysis sets. 
Important protocol deviations may lead to exclusion from the PPS or PK-PPS (Section 9.1). 
Summaries of all important protocol deviations will be produced. 
9.6 
Handling of dropouts or missing data 
The analysis of the co-primary efficacy variables will use NRI for handling of missing data. That 
is, study participants with missing data or who have discontinued IMP prior to Week 16 will be 
considered as nonresponders for the primary analysis. 
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There may be cases where the multiple imputation model fails to converge. In such situations, 
the last observation carried forward (LOCF) approach will instead be used to impute the missing 
data. If LOCF is used instead of multiple imputation for this reason, this will be clearly specified 
in the corresponding table summary. Note that for LOCF imputation, any missing data or data 
collected following discontinuation of IMP will be imputed with the most recent previous value.  
Further details on the MI and LOCF procedures will be provided in the SAP. 
Pharmacokinetic analyses will be based on observed data; no imputation will be used. However, 
if plasma concentration measurements are below the lower level of quantification (LLOQ), then 
for calculation of the derived statistics the result will be set to half of the LLOQ. 
9.7 
Planned analysis and data monitoring 
A primary analysis will be performed after all randomized study participants have completed the 
Week 32 assessments, and a final analysis and clinical study report (CSR) will be prepared once 
all data (through the SFU Visit) have been collected after study completion and database lock. 
9.8 
Determination of sample size 
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10 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS 
10.1 
Appendix 1: Regulatory, ethical, and study oversight 
considerations 
10.1.1 
Regulatory and ethical considerations 
The study will be conducted under the auspices of an IRB/IEC, as defined in local regulations, 
International Council for Harmonisation (ICH)-GCP, and in accordance with the ethical 
principles that have their origin in the Declaration of Helsinki. 
The Investigator/UCB will ensure that an appropriately constituted IRB/IEC that complies with 
the requirements of the current ICH-GCP version or applicable country-specific regulations will 
be responsible for the initial and continuing review and approval of the clinical study. Prior to 
initiation of the study, the Investigator/UCB will forward copies of the protocol, ICF, IB, 
Investigator’s curriculum vitae (if applicable), advertisement (if applicable), and all other study 
participant-related documents to be used for the study to the IRB/IEC for its review and 
approval. 
Before initiating a study, the Investigator will have written and dated full approval from the 
responsible IRB/IEC for the protocol. 
The Investigator will also promptly report to the IRB/IEC all changes in the study, all 
unanticipated problems involving risks to study participants or others, and any protocol 
deviations, to eliminate immediate hazards to study participants. 
The Investigator will not make any changes in the study or study conduct without IRB/IEC 
approval, except where necessary to eliminate apparent immediate hazards to the study 
participants. For minor changes to a previously approved protocol during the period covered by 
the original approval, it may be possible for the Investigator to obtain an expedited review by the 
IRB/IEC as allowed. 
As part of the IRB/IEC requirements for continuing review of approved studies, the Investigator 
will be responsible for submitting periodic progress reports to the IRB/IEC (based on IRB/IEC 
requirements) at intervals appropriate to the degree of study participant risk involved, but no less 
than once per year. The Investigator should provide a final report to the IRB/IEC following study 
completion. 
UCB (or its representative) will communicate safety information to the appropriate regulatory 
authorities and all active Investigators in accordance with applicable regulatory requirements. 
The appropriate IRB/IEC will also be informed by the Investigator or the Sponsor, as specified 
by the applicable regulatory requirements in China. Where applicable, Investigators are to 
provide the Sponsor (or its representative) with evidence of such IRB/IEC notification. 
10.1.2 
Financial disclosure 
Insurance coverage will be handled according to local requirements. 
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Finance and insurance are addressed in the Investigator and/or contract research 
organization (CRO) agreements, as applicable. 
10.1.3 
Informed consent process 
Study participant’s informed consent must be obtained and documented in accordance with local 
regulations, ICH-GCP requirements, and the ethical principles that have their origin in the 
principles of the Declaration of Helsinki. 
Prior to obtaining informed consent, information should be given in a language and at a level of 
complexity understandable to the study participant in both oral and written form by the 
Investigator (or designee). Each study participant will have the opportunity to discuss the study 
and its alternatives with the Investigator. 
Prior to participation in the study, the ICF should be signed and personally dated by the study 
participant and by the person who conducted the informed consent discussion (Investigator or 
designee). The study participant must receive a copy of the signed and dated ICF. As part of the 
consent process, each study participant must consent to direct access to his/her medical records 
for study-related monitoring, auditing, IRB/IEC review, and regulatory inspection. 
If the ICF is amended during the study, the Investigator (or the Sponsor, if applicable) must 
follow all applicable regulatory requirements pertaining to the approval of the amended ICF by 
the IRB/IEC and use of the amended form. 
The study participant may withdraw consent to participate in the study at any time. A study 
participant is considered as enrolled in the study when he/she has signed the ICF. An eCRF must 
not be started, nor may any study-specific procedure be performed for a given study participant, 
without having obtained written consent to participate in the study. 
10.1.4 
Data protection 
UCB staff (or designee) will affirm and uphold the study participant’s confidentiality. 
Throughout this study, all data forwarded to UCB (or designee) will be identified only by the 
study participant number assigned at Screening. 
The Investigator agrees that representatives of UCB, its designee, representatives of the relevant 
IRB/IEC, or representatives of regulatory authorities will be allowed to review that portion of the 
study participant’s primary medical records that directly concerns this study (including, but not 
limited to, laboratory test result reports, ECG reports, admission/discharge summaries for 
hospital admissions occurring during a study participant’s study participation, and autopsy 
reports for deaths occurring during the study). 
The study participant must be informed that personal study-related data will be used by the 
Sponsor in accordance with local data protection law. The level of disclosure must also be 
explained to the study participant. 
The study participant must be informed that his/her medical records may be examined by 
Clinical Quality Assurance auditors or other authorized personnel appointed by the Sponsor, 
by appropriate IRB/IEC members, and by inspectors from regulatory authorities. 
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10.1.5 
Data quality assurance 
All study participant data relating to the study will be recorded in the eCRF unless transmitted 
to the Sponsor or designee electronically (eg, laboratory data). The Investigator is responsible for 
verifying that data entries are accurate and correct by physically or electronically signing the 
eCRF. 
The Investigator must maintain accurate documentation (source data) that supports the 
information entered in the eCRF. 
The Investigator must permit study-related monitoring, audits, IRB/IEC review, and regulatory 
agency inspections and provide direct access to source data documents. 
The Sponsor or designee is responsible for the data management of this study, including quality 
checking of the data. 
Study monitors will perform ongoing source data verification to confirm that data entered into 
the eCRF by authorized site personnel are accurate, contemporaneous, original, and attributable 
from source documents; that the safety and rights of study participants are being protected; and 
that the study is being conducted in accordance with the currently approved protocol and any 
other study agreements, ICH-GCP, and all applicable regulatory requirements. 
All essential documents must be retained by the Investigator for the minimum retention period 
mandatory under the applicable local laws and regulations. The Investigator will contact UCB 
for authorization prior to the destruction of any study records or in the event of accidental loss or 
destruction of any study records. The Investigator will also notify UCB should he/she relocate or 
move the study-related files to a location other than that specified in the Sponsor’s trial master 
file. 
10.1.5.1 
eCRF completion 
The Investigator is responsible for prompt reporting of accurate and complete data in the eCRFs 
and in all required reports. 
Any change or correction to the eCRF after saving must be accompanied by a reason for the 
change. 
Corrections made after the Investigator’s review and approval (by means of a 
password/electronic signature) will be reapproved by the Investigator. 
The Investigator should maintain a list of personnel authorized to enter data into the eCRF. 
Detailed instructions will be provided in the eCRF Completion Guidelines. 
10.1.6 
Source documents 
All source documents must be accurate, clear, unambiguous, permanent, and capable of being 
audited. They should be made using some permanent form of recording (ink, typing, printing, 
optical disc). They should not be obscured by correction fluid or have temporary attachments 
(such as removable self-stick notes). Photocopies and/or printouts of eCRFs are not considered 
acceptable source documents. 
Source documents are original records in which raw data are first recorded. These may include 
hospital/clinic/general practitioner records, charts, diaries, x-rays/CT scans, laboratory results, 
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printouts, pharmacy records, care records, ECG or other printouts, completed scales, QoL 
questionnaires, or video, for example. Source documents should be kept in a secure, limited 
access area. 
Electronic PRO measures and the TB questionnaire will be completed by each study participant 
and will be collected via electronic device. 
Source documents that are computer generated and stored electronically must be printed for 
review by the monitor. Once printed, these copies should be signed and dated by the Investigator 
and become a permanent part of the study participant’s source documents. The Investigator will 
facilitate the process for enabling the monitor to compare the content of the printout and the data 
stored in the computer to ensure all data are consistent. 
Electronic data records must be saved and stored as instructed by UCB (or designee). 
10.1.7 
Study and site closure 
The Sponsor or designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the Sponsor. Study sites will be closed upon study 
completion. A study site is considered closed when all required documents and study supplies 
have been collected and a study-site closure visit has been performed. 
The Investigator may initiate study-site closure at any time, provided there is reasonable cause 
and sufficient notice is given in advance of the intended termination. 
Reasons for the early closure of a study site by the Sponsor or Investigator may include, but are 
not limited to: 
• Failure of the Investigator to comply with the protocol, the requirements of the IRB/IEC or 
local health authorities, the Sponsor's procedures, or GCP guidelines 
• Inadequate recruitment of study participants by the Investigator 
• Discontinuation of further bimekizumab development 
10.1.8 
Publication policy 
The results of this study may be published or presented at scientific meetings. If this is foreseen, 
the Investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. 
This allows the Sponsor to protect proprietary information and to provide comments. 
The Sponsor will comply with the requirements for publication of study results. In accordance 
with standard editorial and ethical practice, the Sponsor will generally support publication of 
multicenter studies only in their entirety and not as individual site data. In this case, a 
coordinating Investigator will be designated by mutual agreement. 
Authorship will be determined by mutual agreement and in line with International Committee 
of Medical Journal Editors authorship requirements. 
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10.2 
Appendix 2: Clinical laboratory tests 
• The tests detailed in Table 10-1 will be performed by the central laboratory, with the 
exception of urine dipsticks and urine pregnancy tests, which will be performed locally at the 
site. 
• Local laboratory results are only required in the event that the central laboratory results are 
not available in time for either IMP administration and/or response evaluation. If a local 
sample is required, it is important that the sample for central analysis is obtained at the same 
time. Additionally, if the local laboratory results are used to make either an IMP decision or 
response evaluation, the results must be entered into the eCRF. 
• Protocol-specific requirements for inclusion or exclusion of study participants are detailed in 
Section 5.1 and Section 5.2, respectively. 
• Additional tests may be performed at any time during the study as determined necessary 
by the Investigator or required by local regulations. 
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Table 10-1: Protocol-required safety laboratory assessments 
Laboratory 
assessments 
Parameters 
Hematology 
Platelet count  
RBC indices: 
MCV 
MCH 
MCHC 
WBC count with 
differential: 
Neutrophils 
Lymphocytes 
Monocytes 
Eosinophils 
Basophils 
RBC count 
Hemoglobin 
Hematocrit 
Clinical chemistrya 
BUN 
Potassium 
AST 
Total bilirubin 
Creatinine 
Sodium 
ALT 
Glucose (nonfasting) 
 
Calcium 
Alkaline 
phosphatase 
Lipid panel 
Chloride 
GGT 
LDH 
Routine urinalysis 
• 
Specific gravity 
• 
pH, glucose, protein, blood, ketones, bilirubin, urobilinogen, nitrite, 
leukocyte esterase by dipstick 
• 
Microscopic examination (if protein, blood, nitrite, or leukocyte esterase 
is abnormal) 
Other Screening tests 
• 
Serum hCG pregnancy test (as needed for WOCBP) by central laboratory 
at Screening and urine pregnancy test locally for all assessments after 
Screening 
• 
IGRA testing 
• 
Urine drug screen 
• 
Serology (HIV antibody, HBsAg, and hepatitis C virus antibody) 
Specific details regarding the handling and processing of serum chemistry, 
hematology, and urinalysis samples are provided in the study laboratory 
manuals. 
All study-required laboratory assessments will be performed by the central 
laboratory, with the exception of urine dipsticks and urine pregnancy tests, 
which will be performed locally at the site. 
The results of each test must be entered into the eCRF. 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; BUN=blood urea nitrogen; eCRF=electronic 
Case Report Form; GGT=gamma glutamyltransferase; HBsAg=hepatitis B surface antigen; hCG=human 
chorionic gonadotropin; HIV=human immunodeficiency virus; IGRA=interferon-gamma release assay; 
INR=international normalized ratio; LDH=lactate dehydrogenase; MCH=mean corpuscular hemoglobin; 
MCHC=mean corpuscular hemoglobin concentration; MCV=mean corpuscular volume; RBC=red blood cell 
count; ULN=upper limit of normal; WBC=white blood cell count; WOCBP=woman of childbearing potential 
a Details of liver chemistry stopping criteria and required actions and follow-up assessments after liver stopping 
or monitoring event are provided in Section 7.1.1 and Appendix 6 (Section 10.6). All events of ALT ≥3×ULN 
and bilirubin ≥2×ULN (>35% direct bilirubin) or ALT ≥3×ULN and INR >1.5, if INR measured, may indicate 
severe liver injury (potential Hy’s Law) and must be reported as an SAE. 
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Investigators must document their review of each laboratory safety report. 
Laboratory/analyte results that could unblind the study will not be reported to investigative sites 
or other blinded personnel until the study has been unblinded. 
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10.3 
Appendix 3: Adverse events – Definitions and procedures for 
recording, evaluating, follow up, and reporting 
Definition of AE 
AE definition 
• 
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally 
associated with the use of IMP, whether or not considered related to the IMP. 
• 
NOTE: An AE can therefore be any unfavorable and unintended sign (including an abnormal 
laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the 
use of IMP. 
 
Events meeting the AE definition 
• 
Any abnormal laboratory test results (hematology, clinical chemistry, or urinalysis) or other 
safety assessments (eg, ECG, radiological scans, vital signs measurements), including those 
that worsen from Baseline, considered clinically significant in the medical and scientific 
judgment of the Investigator (ie, not related to progression of underlying disease). 
• 
Exacerbation of a chronic or intermittent pre-existing condition, including either an increase in 
frequency and/or intensity of the condition. 
• 
New conditions detected or diagnosed after IMP administration even though they may have 
been present before the start of the study. 
• 
Signs, symptoms, or the clinical sequelae of a suspected drug-drug interaction. 
• 
Signs, symptoms, or the clinical sequelae of a suspected overdose of either IMP or a 
concomitant medication. Overdose per se will not be reported as an AE/SAE unless it is an 
intentional overdose taken with possible suicidal/self-harming intent. Such overdoses should be 
reported regardless of sequelae. 
• 
"Lack of efficacy" or "failure of expected pharmacological action" per se will not be reported 
as an AE or SAE. Such instances will be captured in the efficacy assessments. However, the 
signs, symptoms, and/or clinical sequelae resulting from lack of efficacy will be reported as 
AE or SAE if they fulfill the definition of an AE or SAE. 
 
Events NOT meeting the AE definition 
• 
Any clinically significant abnormal laboratory findings or other abnormal safety assessments 
which are associated with the underlying disease, unless judged by the Investigator to be more 
severe than expected for the study participant’s condition. 
• 
The disease/disorder being studied or expected progression, signs, or symptoms of the 
disease/disorder being studied, unless more severe than expected for the study participant’s 
condition. 
• 
Medical or surgical procedure (eg, endoscopy, appendectomy): the condition that leads to the 
procedure is the AE. 
• 
Situations in which an untoward medical occurrence did not occur (social and/or convenience 
admission to a hospital). 
• 
Anticipated day-to-day fluctuations of pre-existing disease(s) or condition(s) present or 
detected at the start of the study that do not worsen. 
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Definition of SAE 
If an event is not an AE per definition above, then it cannot be a SAE even if serious conditions 
are met (eg, hospitalization for signs/symptoms of the disease under study, death due to 
progression of disease). 
A SAE is defined as any untoward medical occurrence that, at any dose: 
a. Results in death 
b. Is life-threatening 
The term 'life-threatening' in the definition of 'serious' refers to an event in which the study participant 
was at risk of death at the time of the event. It does not refer to an event which hypothetically might 
have caused death if it were more severe. 
c. Requires inpatient hospitalization or prolongation of existing hospitalization 
In general, hospitalization signifies that the study participant has been detained (usually involving at 
least an overnight stay) at the hospital or emergency ward for observation and/or treatment that would 
not have been appropriate in the physician’s office or outpatient setting. Complications that occur 
during hospitalization are AEs. If a complication prolongs hospitalization or fulfills any other serious 
criteria, the event is serious. When in doubt as to whether “hospitalization” occurred or was necessary, 
the AE should be considered serious. 
Hospitalization for elective treatment of a pre-existing condition that did not worsen from Baseline is 
not considered an AE. 
d. Results in persistent disability/incapacity 
• 
The term disability means a substantial disruption of a person’s ability to conduct normal life 
functions. 
• 
This definition is not intended to include experiences of relatively minor medical significance, 
such as uncomplicated headache, nausea, vomiting, diarrhea, influenza, and accidental trauma 
(eg, sprained ankle) which may interfere with or prevent everyday life functions but do not 
constitute a substantial disruption. 
e. Is a congenital anomaly/birth defect 
f. Important medical events: 
• 
Medical or scientific judgment should be exercised in deciding whether SAE reporting is 
appropriate in other situations, such as important medical events that may not be immediately 
life-threatening or result in death or hospitalization but may jeopardize the study participant or 
may require medical or surgical intervention to prevent one of the other outcomes listed in the 
above definition. These events should usually be considered serious. 
• 
Examples of such events include, but are not limited to, potential Hy’s law, invasive or 
malignant cancers, intensive treatment in an emergency room or at home for allergic 
bronchospasm, blood dyscrasias or convulsions that do not result in hospitalization, or 
development of drug dependency or drug abuse. 
 
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Recording and follow up of AE and/or SAE 
AE and SAE recording 
• 
When an AE/SAE occurs, it is the responsibility of the Investigator to review all 
documentation (eg, hospital progress notes, laboratory reports, and diagnostics reports) related 
to the event. 
• 
The Investigator will then record all relevant AE/SAE information in the eCRF. 
• 
It is not acceptable for the Investigator to send photocopies of the study participant’s medical 
records to UCB in lieu of completion of the AE/SAE eCRF page. 
• 
There may be instances when copies of medical records for certain cases are requested by 
UCB. In this case, all study participant identifiers, with the exception of the study participant 
number, will be redacted on the copies of the medical records before submission to UCB. 
• 
The Investigator will attempt to establish a diagnosis of the event based on signs, symptoms, 
and/or other clinical information. Whenever possible, the diagnosis (not the individual 
signs/symptoms) will be documented as the AE/SAE. 
Assessment of intensity 
The Investigator will make an assessment of intensity for each AE and SAE reported during the study 
and assign it to 1 of the following categories:  
• 
Mild: An event that is easily tolerated by the study participant, causing minimal discomfort and 
not interfering with everyday activities. 
• 
Moderate: An event that causes sufficient discomfort and interferes with normal everyday 
activities. 
• 
Severe: An event that prevents normal everyday activities. An AE that is assessed as severe 
should not be confused with a SAE. Severe is a category utilized for rating the intensity of an 
event; and both AEs and SAEs can be assessed as severe. 
• 
An event is defined as ‘serious’ when it meets ≥1 of the predefined outcomes as described in 
the definition of a SAE, NOT when it is rated as severe (eg, a severe AE may be either serious 
or not serious, depending on whether these criteria are also met). 
The National Cancer Institute Common Terminology Criteria for Adverse Events should be used as a 
supportive standardization instrument to evaluate AEs and SAEs, but the final intensity grading by the 
Investigator must be mild, moderate, or severe. 
 
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Assessment of causality 
• 
The Investigator is obligated to assess the relationship between IMP and each occurrence of 
each AE/SAE. 
• 
A "reasonable possibility" of a relationship conveys that there are facts, evidence, and/or 
arguments to suggest a causal relationship, rather than a relationship cannot be ruled out. 
• 
The Investigator will use clinical judgment to determine the relationship. 
• 
Alternative causes, such as underlying disease(s), concomitant therapy, and other risk factors, 
as well as the temporal relationship of the event to IMP administration will be considered and 
investigated. 
• 
The Investigator will also consult the IB and/or Product Information, for marketed products, in 
his/her assessment. 
• 
For each AE/SAE, the Investigator must document in the medical notes that he/she has 
reviewed the AE/SAE and has provided an assessment of causality. 
• 
There may be situations in which a SAE has occurred and the Investigator has minimal 
information to include in the initial report to UCB. However, it is very important that the 
Investigator always make an assessment of causality for every event before the initial 
transmission of the SAE data to UCB. 
• 
The Investigator may change his/her opinion of causality in light of follow-up information and 
send a SAE follow-up report with the updated causality assessment. 
• 
The causality assessment is one of the criteria used when determining regulatory reporting 
requirements. 
 
Follow up of AEs and SAEs 
• 
The Investigator is obligated to perform or arrange for the conduct of supplemental 
measurements and/or evaluations as medically indicated or as requested by UCB to elucidate 
the nature and/or causality of the AE or SAE as fully as possible. This may include additional 
laboratory tests or investigations, histopathological examinations, or consultation with other 
health care professionals. 
• 
An AE should be followed until it has resolved, has a stable sequelae, the Investigator 
determines that it is no longer clinically significant, or the study participant is lost to follow up. 
This follow-up requirement applies to AEs, SAEs, and AEs of special interest. 
• 
If a study participant dies during participation in the study or during a recognized follow-up 
period, the Investigator will provide UCB with a copy of any postmortem findings, including 
histopathology. 
• 
New or updated information will be recorded in the originally completed eCRF. 
• 
The Investigator will submit any updated SAE data to UCB within 24 hours of receipt of the 
information. 
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Reporting of SAE 
SAE reporting to UCB via an electronic data collection tool 
• 
The primary mechanism for reporting a SAE to UCB will be the electronic data collection tool. 
• 
If the electronic system is unavailable for more than 24 hours, then the site will use the paper 
SAE data collection tool (see next section). 
• 
The site will enter the SAE data into the electronic system as soon as it becomes available. 
• 
After the study is completed at a given site, the electronic data collection tool will be taken off-
line to prevent the entry of new data or changes to existing data. 
• 
If a site receives a report of a new SAE from a study participant or receives updated data on a 
previously reported SAE after the electronic data collection tool has been taken off-line, then 
the site can report this information on a paper SAE form (see next section) or to the UCB 
Study Physician by telephone. 
• 
Contacts for SAE reporting can be found in SAFETY REPORTING OF ADVERSE EVENTS 
(SERIOUS AND NONSERIOUS) AND DEVICE DEFICIENCIES. 
 
SAE reporting to UCB via paper CRF 
• 
Facsimile transmission of the SAE paper CRF is the preferred method to transmit this 
information to the UCB Study Physician. 
• 
In rare circumstances and in the absence of facsimile equipment, notification by telephone is 
acceptable with a copy of the SAE data collection tool sent by overnight mail or courier 
service. 
• 
Initial notification via telephone does not replace the need for the Investigator to complete and 
sign the SAE CRF pages within the designated reporting time frames. 
• 
Contacts for SAE reporting can be found in SAFETY REPORTING OF ADVERSE EVENTS 
(SERIOUS AND NONSERIOUS) AND DEVICE DEFICIENCIES. 
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10.4 
Appendix 4: Contraceptive guidance and collection of 
pregnancy information 
Definitions 
Woman of childbearing potential (WOCBP): A woman is considered fertile following 
menarche and until becoming postmenopausal unless permanently sterile (see below). 
Women in the following categories are not considered WOCBP: 
1. Premenarchal 
2. Premenopausal female with 1 of the following: 
− Documented hysterectomy 
− Documented bilateral salpingectomy 
− Documented bilateral oophorectomy 
Note: Documentation can come from the site personnel’s review of the study participant’s 
medical records, medical examination, or medical history interview. 
3. Postmenopausal female 
− A postmenopausal state is defined as no menses for 12 months without an alternative 
medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal 
range may be used to confirm a postmenopausal state in women not using hormonal 
contraception or hormonal replacement therapy (HRT). However, in the absence of 
12 months of amenorrhea, a single FSH measurement is insufficient. 
− Females on HRT and whose menopausal status is in doubt will be required to use one of 
the nonestrogen hormonal highly effective contraception methods if they wish to 
continue their HRT during the study. Otherwise, they must discontinue HRT to allow 
confirmation of postmenopausal status before study enrollment. 
Contraception guidance 
Female study participants 
Female study participants of childbearing potential are eligible to participate if they agree to use 
a highly effective method of contraception consistently and correctly as described in Table 10-2. 
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Table 10-2: Highly effective contraceptive methods 
Highly effective contraceptive methods that are user dependenta 
Failure rate of <1% per year when used consistently and correctly. 
Combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of 
ovulation 
• 
Oral 
• 
Intravaginal 
• 
Transdermal 
Progestogen only hormonal contraception associated with inhibition of ovulation 
• 
Oral 
• 
Injectable 
Highly effective methods that are user independent 
Implantable progestogen-only hormonal contraception associated with inhibition of ovulation 
• 
IUD 
• 
IUS 
• 
Bilateral tubal occlusion 
Vasectomized partner 
A vasectomized partner is a highly effective contraception method provided that the partner is the sole 
male sexual partner of the WOCBP and the absence of sperm has been confirmed. If not, an additional 
highly effective method of contraception should be used. 
Sexual abstinence 
Sexual abstinence is considered a highly effective method only if defined as refraining from heterosexual 
intercourse during the entire period of risk associated with the IMP. The reliability of sexual abstinence 
needs to be evaluated in relation to the duration of the study and the preferred and usual lifestyle of the 
study participant. 
IMP=investigational medicinal product; IUD=intrauterine device; IUS=intrauterine hormone-releasing system; 
WOCBP=woman of childbearing potential 
Note: In case of newly started contraception pills/IUDs, Investigator should consider the correct timing of 
starting/applying such methods in relation to the menstrual cycle and the manufacturing instruction as to when 
these newly started methods would become effective. 
a Typical use failure rates may differ from those when used consistently and correctly. Use should be consistent 
with local regulations regarding the use of contraceptive methods for study participants participating in clinical 
studies. 
Pregnancy testing 
• Woman of childbearing potential should only be included after a confirmed menstrual period 
and a negative highly sensitive serum pregnancy test. 
• Additional pregnancy testing should be performed as indicated in the SoA (Table 1-1) and as 
required locally. 
• Pregnancy testing will be performed whenever a menstrual cycle is missed or when 
pregnancy is otherwise suspected. 
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Male study participants with partners who become pregnant 
• The Investigator will attempt to collect pregnancy information on any male study 
participant’s female partner who becomes pregnant while the male study participant is in this 
study. This applies only to male study participants who receive bimekizumab. If the study 
participant is later found to be on placebo, then pregnancy data collection can stop. 
• In cases where the partner of a male study participant enrolled in a clinical study becomes 
pregnant, the Investigator or designee is asked to contact the study participant to request 
consent of the partner via the Partner Pregnancy Consent Form that has been approved by the 
responsible IRB/IEC and should be available in the Investigator site file. In case of questions 
about the consent process, the Investigator may contact the UCB/CRO contract monitor for 
the study. The Investigator will complete the information in the eCRF only after the partner 
has agreed that additional information can be captured and has provided the signed Partner 
Pregnancy Consent Form. UCB’s PS department is also the primary contact for any questions 
related to the data collection for the partner pregnancy, eventual birth, and follow up. 
• After obtaining the necessary signed informed consent from the pregnant female partner 
(and/or parent/legal representative), the Investigator will record pregnancy information on 
the appropriate form and submit it to the Sponsor within 24 hours of receipt of the 
information. The female partner will also be followed to determine the outcome of the 
pregnancy. Information on the status of the mother and child will be forwarded to the 
Sponsor. Generally, the follow up will be ≥30 days after the delivery date. Any termination 
of the pregnancy will be reported regardless of fetal status (presence or absence of 
anomalies) or indication for the procedure. 
Female study participants who become pregnant 
• Any female study participant who becomes pregnant while participating in the study will 
discontinue IMP (see Section 8.3.5). 
• The Investigator will collect pregnancy information on any female study participant who 
becomes pregnant while participating in this study. Information will be recorded on the 
appropriate form and submitted to the Sponsor within 24 hours of receipt of the information. 
The study participant will be followed to determine the outcome of the pregnancy. The 
Investigator will collect follow-up information on the study participant and the neonate, and 
the information will be forwarded to the Sponsor. Generally, the follow up will be ≥30 days 
after the delivery date. Any termination of pregnancy will be reported, regardless of fetal 
status (presence or absence of anomalies) or indication for the procedure. 
• While pregnancy itself is not considered to be an AE or SAE, any pregnancy complication or 
elective termination of a pregnancy will be reported as an AE or SAE. A spontaneous 
abortion is always considered to be an SAE and will be reported as such. Any poststudy 
pregnancy-related SAE considered reasonably related to the IMP by the Investigator will be 
reported to the Sponsor as described in Section 8.3.5. While the Investigator is not obligated 
to actively seek this information in former study participants, he or she may learn of an SAE 
through spontaneous reporting. 
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10.5 
Appendix 5: Genetics 
Not applicable. 
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10.6 
Appendix 6: Liver safety – suggested actions and follow-up 
assessments and IMP rechallenge guidelines 
The PDILI IMP discontinuation criteria for this study are provided in Section 7.1.1, with the 
accompanying required follow-up investigation and monitoring detailed below. All PDILI events 
must be reported as an AE and reported to the study site and Sponsor within 24 hours of receipt 
of the information. Any PDILI event that meets the criterion for potential Hy’s Law must be 
reported as an AE of special interest (see Section 8.3.6), and, if applicable, also reported as an 
SAE (see Section 8.3.4). 
Evaluation of PDILI consists of the diagnostic testing and continued monitoring included in 
Table 10-4 (specific tests dependent on laboratory results and corresponding symptoms) and 
consultation with a local hepatologist (if applicable; discussed in Section 10.6.1). The local 
hepatologist is the expert usually consulted by the treating physician for assessment and 
management of potential hepatic disease. This would usually be a hepatologist but may be a 
gastroenterologist. Additional investigation and monitoring may be required and adapted based 
on the diagnosis after the cause of the liver injury/abnormality is confirmed (details in 
Section 7.1.1.1). 
The results of all monitoring, including laboratory testing and other testing, should be made 
available to the study site and Sponsor. 
All initial tests resulting in abnormal hepatic laboratory values need to be repeated, but 
appropriate medical action must not be delayed waiting for the repeat result. 
If tests are done locally for more rapid results, a concurrent sample should also be sent to the 
central laboratory whenever possible. Medical care decisions are to be made initially using the 
most rapidly available results, and a conservative approach must be taken if the results from the 
2 laboratory tests are significantly different. Data from the local and central laboratory are to be 
recorded on the applicable eCRF pages. 
When IMP is discontinued, all concomitant medications and herbal supplements that are not 
medically necessary should also be discontinued. In these cases, the Investigator should also 
consider dose reduction for medically necessary concomitant medication and consider changing 
any medically required concomitant medication known to be hepatotoxic to a suitable 
alternative. 
When IMP is stopped due to PDILI (as described in Section 7.1.1), IMP must be permanently 
discontinued unless a subsequent alternative diagnosis fully explains the hepatic findings. If a 
subsequent alternative diagnosis fully explains the hepatic findings, and the requirements 
provided in Section 10.6.2.1 are met, rechallenge with IMP may be appropriate. 
The approach to investigate PDILI is summarized in Table 10-3. 
 
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Table 10-3: Required investigations and follow up for PDILI 
Laboratory value 
 
Immediate 
Follow up 
ALT or AST 
Total 
bilirubin 
Symptomsa of 
hepatitis or 
hypersensitivity 
Consultation 
requirements 
Actions 
Testing 
Evaluation 
≥3×ULN 
≥2×ULNb 
N/A 
Hepatology consultc 
Medical Monitor 
must be notified 
within 24 hours 
(eg, by laboratory 
alert) and study 
participant discussed 
with Medical 
Monitor ASAP. 
Immediate IMP 
discontinuationd 
Essential: Must have 
repeat liver chemistry 
values and additional 
testing completed 
ASAP (see 
Section 10.6.3); 
recommended to 
occur at the site with 
HCP. 
Monitoring of liver 
chemistry values at least 
twice per week until 
values normalize, 
stabilize, or return to 
within Baseline values.e 
≥3×ULN 
N/A 
Yes 
≥8×ULN 
N/A 
N/A 
Need for hepatology 
consult to be 
discussed (required if 
ALT or AST 
≥8×ULN) 
Medical Monitor 
must be notified 
within 24 hours 
(eg, by laboratory 
alert) and study 
participant discussed 
with Medical 
Monitor ASAP. 
≥5×ULN 
(and ≥2× 
Baseline) and 
<8×ULN 
<2×ULN 
No 
Discussion with 
Medical Monitor 
required. 
Consider need for 
hepatology consult if 
there is no evidence 
of resolution (see 
Further investigation – 
immediate IMP 
discontinuation not 
Essential: Every 
attempt must be made 
to have repeat liver 
chemistry values and 
additional testing 
completed within 
48 hours at the site 
with HCP (see 
Section 10.6.3). 
Monitoring of liver 
chemistry values at least 
twice per week for 
2 weeks.e 
• Immediate IMP 
discontinuation 
required if liver 
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Table 10-3: Required investigations and follow up for PDILI 
Laboratory value 
 
Immediate 
Follow up 
ALT or AST 
Total 
bilirubin 
Symptomsa of 
hepatitis or 
hypersensitivity 
Consultation 
requirements 
Actions 
Testing 
Evaluation 
follow-up 
requirements).c 
required (see 
Section 10.6.2). 
 
IMP discontinuation 
required if any of the 
following occur: 
• Study participant 
cannot comply with 
monitoring schedule. 
• Liver chemistry 
values continue to 
increase. 
• Liver chemistry 
values remain 
≥5×ULN (and 
≥2× Baseline) after 
4 weeks of 
monitoring without 
evidence of 
resolution. 
chemistry values 
continue to increase. 
After 2 weeks of 
monitoring liver 
chemistry values: 
• ALT or AST remains 
≥5×ULN to <8×ULN, 
IMP should be 
temporarily withheld, 
and study participant 
should undergo repeat 
test in 2 weeks. 
• Continue IMP if ALT 
or AST values 
<5×ULN; continue to 
monitor at least twice 
per week until values 
normalize, stabilize, or 
return to within 
Baseline values. 
• If ALT or AST remains 
≥5×ULN after second 
retest, immediate IMP 
discontinuation 
required. 
• Continue to monitor 
until values normalize, 
stabilize, or return to 
within Baseline values.e 
ALP=alkaline phosphatase; ALT=alanine aminotransferase; ASAP=as soon as possible; AST=aspartate aminotransferase; HCP=health care practitioner; 
IMP=investigational medicinal product; N/A=not applicable; PDILI=potential drug-induced liver injury; ULN=upper limit of normal 
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Table 10-3: Required investigations and follow up for PDILI 
Laboratory value 
 
Immediate 
Follow up 
ALT or AST 
Total 
bilirubin 
Symptomsa of 
hepatitis or 
hypersensitivity 
Consultation 
requirements 
Actions 
Testing 
Evaluation 
a Hepatitis symptoms include fatigue, nausea, vomiting, and right upper quadrant pain or tenderness; hypersensitivity symptoms include eosinophilia, rash, 
and fever (without clear alternative cause). 
b If the study participant also has ≥2×ULN ALP, the possibility of an indication of biliary obstruction should be discussed with the Medical Monitor. 
c Details provided in Section 10.6.1. The local hepatologist is the expert usually consulted by the treating physician for assessment and management of 
potential hepatic disease. This would usually be a hepatologist but may be a gastroenterologist. 
d Details are provided in Section 10.6.2. 
e Unless an alternative monitoring schedule is agreed by the Investigator and responsible UCB Study Physician. Determination of stabilization is at the 
discretion of the Investigator in consultation with the hepatologist (as applicable) and responsible UCB Study Physician, as needed. 
 
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10.6.1 
Consultation with Medical Monitor and local hepatologist 
Potential drug-induced liver injury events require notification of the Medical Monitor or 
UCB Study Physician within 24 hours (eg, by laboratory alert), and the study participant must be 
discussed with the Medical Monitor or UCB Study Physician as soon as possible. If required, the 
study participant must also be discussed with the local hepatologist. The local hepatologist is the 
expert usually consulted by the treating physician for assessment and management of potential 
hepatic disease. This would usually be a hepatologist but may be a gastroenterologist. If 
determined necessary, this discussion should be followed by a full hepatology assessment 
(see Section 10.6.3) and SAE report (if applicable). 
10.6.2 
Immediate action: determination of IMP discontinuation 
All PDILI events require immediate action, testing, and monitoring. 
The immediate action is dependent on the laboratory values and symptoms of hepatitis or 
hypersensitivity and ranges from continuation of IMP (followed by immediate investigation) 
to immediate and permanent discontinuation (see Section 7.1.1 and Table 10-3 for details). 
When IMP is discontinued, all concomitant medications and herbal supplements that are not 
medically necessary should also be discontinued. The Investigator should also consider dose 
reduction for medically necessary concomitant medication and consider changing any medically 
required concomitant medication known to be hepatotoxic to a suitable alternative. 
10.6.2.1 
IMP restart/rechallenge 
Study participants who are immediately discontinued from IMP due to having met certain 
criteria for PDILI (as described in Section 7.1.1 and Table 10-3), but for whom an alternative 
diagnosis is confirmed, ie, drug-induced liver injury is excluded, can rarely restart IMP. 
Rechallenge with IMP can occur only if ALL of the following requirements are met: 
• The results of additional testing and monitoring described in Section 10.6.3 and 
Section 7.1.1.1 confirm a nondrug-related cause for the abnormal hepatic laboratory 
parameters and any associated symptoms (ie, a subsequent alternative diagnosis fully 
explains the hepatic findings). 
• No alternative treatment options are available to the study participant. 
• The study participant has shown clear therapeutic benefit from the IMP. 
• Study participant’s ALT or AST elevations do not exceed ≥5×ULN. 
• Study participant’s total bilirubin is <2×ULN. 
• Study participant has no signs or symptoms of hypersensitivity or hepatitis. 
• The rechallenge is approved by the UCB Study Physician and a hepatologist. The 
hepatologist must be external to UCB. It is recommended that the hepatologist be a local 
hepatology expert or the hepatologist treating the study participant. 
• Study participant agrees to the Investigator-recommended monitoring plan and understands 
his/her individual benefit/risk for restarting IMP and this is adequately documented. 
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10.6.3 
Testing: identification/exclusion of alternative etiology 
The measurements and additional information required for the assessment of PDILI events when 
there is a reasonable possibility that they may have been caused by the IMP are detailed in 
Table 10-4 (laboratory measurements) and Table 10-5 (additional information). Results of the 
laboratory measurements and information collected are to be submitted to the Sponsor on the 
corresponding eCRF. If the medical history of the study participant indicates a requirement for 
other assessments not included below, these additional assessments should be completed and 
submitted, as applicable. 
All blood samples should be stored, if possible. If tests are done locally for more rapid results, a 
concurrent sample must also be sent to the central laboratory. 
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Table 10-4: PDILI laboratory measurements 
Virology-  
related 
Hepatitis A IgM antibody 
HBsAg 
Hepatitis E IgM antibody 
HBcAb-IgM 
Hepatitis C RNA 
Cytomegalovirus IgM antibody 
Epstein-Barr viral capsid antigen IgM antibody (if unavailable, obtain heterophile 
antibody or monospot testing) 
Immunology 
Anti-nuclear antibody (qualitative and quantitative) 
Anti-smooth muscle antibody (qualitative and quantitative) 
Type 1 anti-liver kidney microsomal antibodies (qualitative and quantitative) 
Hematology 
Eosinophil count 
Urinalysis 
Urine drug screena 
Chemistry 
Amylase 
Sodium, potassium, chloride, glucose, blood urea nitrogen, creatinine 
Total bilirubin, ALP, AST, ALT, gamma-glutamyltransferase, total cholesterol, 
albumin 
If total bilirubin ≥1.5×ULN, obtain fractionated bilirubin to obtain % direct bilirubin 
Serum creatine phosphokinase and lactate dehydrogenase to evaluate possible muscle 
injury causing transaminase elevation 
Additional 
Prothrombin time/INRb 
Serum pregnancy testc 
PK sample 
ALP=alkaline phosphatase; ALT=alanine aminotransferase; AST=aspartate aminotransferase; 
HBcAb-IgM=anti-hepatitis B core antibody-IgM; HBsAg=hepatitis B surface antigen; IgM=immunoglobulin 
M; INR=international normalized ratio; PDILI=potential drug-induced liver injury; PK=pharmacokinetics; 
RNA=ribonucleic acid; ULN=upper limit of normal; WOCBP=woman of childbearing potential 
a Tests in addition to the specified analytes may be performed based on the Investigator’s medical judgment and 
study participant history. 
b Measured only for study participants with ALT >8×ULN, elevations in total bilirubin, and symptoms of 
hepatitis or hypersensitivity. Hepatitis symptoms include fatigue, nausea, vomiting, and right upper quadrant 
pain or tenderness; hypersensitivity symptoms include eosinophilia, rash, and fever (without clear alternative 
cause). 
c For WOCBP. 
 
 
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Table 10-5: PDILI information to be collected 
New or updated information 
• Concomitant prescriptions and over-the-counter medications (eg, acetaminophen, herbal 
remedies, vitamins); dosages and dates should be included. 
• Pertinent medical history, including the following: 
− History of liver disease (eg, autoimmune hepatitis, nonalcoholic steatohepatitis, or 
other “fatty liver disease”) 
− Adverse reactions to drugs 
− Allergies 
− Relevant family history or inheritable disorders (eg, Gilbert’s syndrome, 
alpha-1 antitrypsin deficiency) 
− Recent travel 
− Progression of malignancy involving the liver (Note: Metastatic disease to the liver, by 
itself, should not be used as an explanation for significant AST and/or ALT elevations.) 
• The appearance or worsening of clinical symptoms of hepatitis or hypersensitivity 
(eg, fatigue, nausea, vomiting, right upper quadrant pain or tenderness, decreased appetite, 
abdominal pain, jaundice, fever, or rash) 
• Recent clinically significant hypotension or hypoxemia with compromised 
cardiopulmonary function 
• Alcohol and illicit drug use 
• Results of liver imaging or liver biopsy, if done 
• Results of any specialist or hepatology consult, if done 
• Any postmortem/pathology reports 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; PDILI=potential drug-induced liver injury 
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10.7 
Appendix 7: Medical device AEs, ADEs, SAEs, and device 
deficiencies: definition and procedures for recording, 
evaluating, follow up, and reporting 
The definitions and procedures detailed in this appendix are in accordance with ISO 14155. 
Both the Investigator and the Sponsor will comply with all local medical device reporting 
requirements. 
The detection and documentation procedures described in this protocol apply to all Sponsor 
medical devices provided for use in the study. See Section 6.1.1 for the list of Sponsor medical 
devices. 
10.7.1 
Definition of AE and adverse device effect 
AE and ADE Definition 
• 
An AE is defined as any untoward medical occurrence, unintended disease or injury, or 
untoward clinical signs (including abnormal laboratory finding) in study participants, users, or 
other persons, whether or not related to the investigational medical device. This definition 
includes events related to the investigational medical device or comparator and events related 
to the procedures involved except for events in users or other persons, which only include 
events related to investigational devices. 
• 
An ADE is defined as an AE related to the use of an investigational medical device. This 
definition includes any AEs resulting from insufficient or inadequate instructions for use, 
deployment, implantation, installation, or operation, or any malfunction of the investigational 
medical device as well as any event resulting from use error or from intentional misuse of the 
investigational medical device. 
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10.7.2 
Definition of SAE, SADE, and USADE 
If an event is not an AE per definition above, then it cannot be a SAE even if serious conditions 
are met (eg, hospitalization for signs/symptoms of the disease under study, death due to 
progression of disease). 
A SAE is an AE that: 
a. Led to death 
b. Led to serious deterioration in the health of the participant, that either resulted in: 
1. A life-threatening illness or injury. The term life-threatening in the definition of serious refers to an 
event in which the participant was at risk of death at the time of the event. It does not refer to an 
event which hypothetically might have caused death if it were more severe. 
2. A permanent impairment of a body structure or a body function. 
3. Inpatient or prolonged hospitalization, planned hospitalization for a pre-existing condition, or a 
procedure required by the protocol, without serious deterioration in health, is not considered a 
SAE. 
4. Medical or surgical intervention to prevent life-threatening illness or injury or permanent 
impairment to a body structure or a body function. 
c. Led to fetal distress, fetal death, or a congenital abnormality or birth defect 
SADE definition 
• 
A SADE is defined as an ADE that has resulted in any of the consequences characteristic of a 
SAE. 
USADE definition 
• 
An unanticipated serious adverse device effect (USADE) is a SADE which by its nature, 
incidence, severity, or outcome has not been identified in the current version of the risk 
analysis report (see Section 8.3.9). 
10.7.3 
Definition of device deficiency 
Device deficiency definition 
• 
A device deficiency is an inadequacy of a medical device with respect to its identity, quality, 
durability, reliability, safety, or performance. Device deficiencies include malfunctions, use 
errors, and inadequate labeling. 
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10.7.4 
Recording and follow up of AE and/or SAE and device deficiencies 
AE, SAE, and device deficiency recording 
• 
When an AE/SAE/device deficiency occurs, it is the responsibility of the Investigator to review 
all documentation (eg, hospital progress notes, laboratory reports, and diagnostics reports) 
related to the event. 
• 
The Investigator will then record all relevant AE/SAE/device deficiency information in the 
participant’s medical records, in accordance with the Investigator’s normal clinical practice, 
and on the appropriate form of the eCRF. 
• 
It is not acceptable for the Investigator to send photocopies of the participant’s medical records 
to UCB in lieu of completion of the AE/SAE/device deficiency eCRF page. 
• 
There may be instances when copies of medical records for certain cases are requested by 
UCB. In this case, all participant identifiers, with the exception of the participant number, will 
be redacted on the copies of the medical records before submission to UCB. 
• 
The Investigator will attempt to establish a diagnosis of the event based on signs, symptoms, 
and/or other clinical information. Whenever possible, the diagnosis (not the individual 
signs/symptoms) will be documented as the AE/SAE. 
• 
For device deficiencies, it is very important that the Investigator describes any corrective or 
remedial actions taken to prevent recurrence of the deficiency. 
o A remedial action is any action other than routine maintenance or servicing of a 
medical device where such action is necessary to prevent recurrence of a device 
deficiency. This includes any amendment to the device design to prevent recurrence. 
The Investigator should complete a Product Complaint Form for all reported device 
deficiencies. 
Assessment of intensity 
The Investigator will make an assessment of intensity for each AE/SAE/device deficiency reported 
during the study and assign it to 1 of the following categories: 
• 
Mild: An event that is easily tolerated by the participant, causing minimal discomfort and not 
interfering with everyday activities. 
• 
Moderate: An event that causes sufficient discomfort and interferes with normal everyday 
activities. 
• 
Severe: An event that prevents normal everyday activities. An AE that is assessed as severe 
should not be confused with a SAE. Severe is a category utilized for rating the intensity of an 
event, and both AEs and SAEs can be assessed as severe. 
• 
An event is defined as serious when it meets ≥1 of the predefined outcomes as described in the 
definition of a SAE, NOT when it is rated as severe. 
 
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Assessment of causality 
• 
The Investigator is obligated to assess the relationship between study intervention and each 
occurrence of each AE/SAE/device deficiency. 
• 
A “reasonable possibility” of a relationship conveys that there are facts, evidence, and/or 
arguments to suggest a causal relationship, rather than a relationship cannot be ruled out. 
• 
The Investigator will use clinical judgment to determine the relationship. 
• 
Alternative causes, such as underlying disease(s), concomitant therapy, and other risk factors, 
as well as the temporal relationship of the event to study intervention administration, will be 
considered and investigated. 
• 
The Investigator will also consult the IB in his/her assessment. 
• 
For each AE/SAE/device deficiency, the Investigator must document in the medical notes that 
he/she has reviewed the AE/SAE/device deficiency and has provided an assessment of 
causality. 
• 
There may be situations in which a SAE has occurred and the Investigator has minimal 
information to include in the initial report to UCB. However, it is very important that the 
Investigator always make an assessment of causality for every event before the initial 
transmission of the SAE data to UCB. 
• 
The Investigator may change his/her opinion of causality in light of follow-up information and 
send a SAE follow-up report with the updated causality assessment. 
• 
The causality assessment is one of the criteria used when determining regulatory reporting 
requirements. 
 
Follow up of AE/SAE/device deficiency 
• 
The Investigator is obligated to perform or arrange for the conduct of supplemental 
measurements and/or evaluations as medically indicated or as requested by UCB to elucidate 
the nature and/or causality of the AE/SAE/device deficiency as fully as possible. This may 
include additional laboratory tests or investigations, histopathological examinations, or 
consultation with other health care professionals. 
• 
If a participant dies during participation in the study or during a recognized follow-up period, 
the Investigator will provide UCB with a copy of any post-mortem findings, including 
histopathology. 
• 
New or updated information will be recorded in the originally completed CRF. 
• 
The Investigator will submit any updated SAE data to UCB within 24 hours of receipt of the 
information. 
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10.8 
Appendix 8: Rapid alert procedures 
Not applicable. 
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10.9 
Appendix 9: Country-specific requirements 
Not applicable. 
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10.10 
Appendix 10: Abbreviations and trademarks 
ADAb 
antidrug antibody 
ADE 
adverse device effect 
AE 
adverse event 
AESI 
adverse event of special interest 
ALP 
alkaline phosphatase 
ALT 
alanine aminotransferase 
AMS 
Active Medication Set 
AST 
aspartate aminotransferase 
BP 
blood pressure 
BSA 
body surface area 
CT 
computed axial tomography 
CI 
confidence interval 
CMH 
Cochran-Mantel-Haenszel 
COVID-19 
coronavirus disease 2019 
CPM 
Clinical Project Manager 
CRO 
contract research organization 
CSR 
clinical study report 
CV 
cardiovascular 
DLQI 
Dermatology Life Quality Index 
ECG 
electrocardiogram 
eCRF 
electronic Case Report Form 
ePRO 
electronic patient-reported outcome 
ES 
Enrolled Set 
FAS 
Full Analysis Set 
FSH 
follicle stimulating hormone 
GCP 
Good Clinical Practice 
GI 
gastrointestinal 
HBcAb 
anti-hepatitis B core antibody 
HBsAg 
hepatitis B surface antigen 
HBV 
hepatitis B virus 
HCV 
hepatitis C virus 
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HIV 
human immunodeficiency virus 
HLT 
high level term 
HRT 
hormonal replacement therapy 
IB 
Investigator’s Brochure 
IBD 
inflammatory bowel disease 
ICF 
Informed Consent Form 
ICH 
International Council for Harmonisation 
IEC 
Independent Ethics Committee 
IGA 
Investigator’s Global Assessment 
IGA 0 
Investigator’s Global Assessment response clear (0) with a ≥2-category 
improvement relative to Baseline 
IGA 0/1 
Investigator’s Global Assessment response clear (0) or almost clear (1) 
with a ≥2-category improvement relative to Baseline 
IgG1 
immunoglobulin G1 
IGRA 
interferon-gamma release assay  
IL 
interleukin 
IMP 
investigational medicinal product 
IRB 
Institutional Review Board 
IRT 
interactive response technology 
LFT 
liver function test 
LLOQ 
lower level of quantification 
LTBI 
latent tuberculosis infection 
LOCF 
last observation carried forward 
mAb 
monoclonal antibody 
MAR 
missing at random 
MCMC 
Markov-Chain Monte Carlo 
MI 
multiple imputation 
M. tuberculosis 
Mycobacterium tuberculosis 
NRI 
nonresponder imputation 
NTMB 
nontuberculous mycobacterium 
P-SIM 
Psoriasis-Symptom and Impact Measure 
PASI 
Psoriasis Area and Severity Index 
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PASI75/90/100 
75% or greater/90% or greater/100% improvement from Baseline in the 
Psoriasis Area and Severity Index score 
PD 
pharmacodynamic(s) 
PDILI 
potential drug-induced liver injury 
PEOT 
Premature End of Treatment 
PK 
pharmacokinetic(s) 
PK-PPS 
Pharmacokinetics Per-Protocol Set 
PPS 
Per-Protocol Set 
PRN 
as needed, pro re nata 
PS 
Patient Safety 
PsA 
psoriatic arthritis 
PSD 
Patient Symptom Diary 
PSO 
psoriasis 
Q4W 
every 4 weeks 
Q8W 
every 8 weeks 
QoL 
quality of life 
RS 
Randomized Set 
SADE 
serious adverse device effect 
SAE 
serious adverse event 
SAP 
Statistical Analysis Plan 
sc 
subcutaneous 
SFU 
Safety Follow-Up 
SIB 
suicidal ideation and behavior 
SoA 
Schedule of Activities 
SOC 
system organ class 
SS 
Safety Set 
TB 
tuberculosis 
TEAE 
treatment-emergent adverse event 
TEMA 
treatment-emergent markedly abnormal 
TNF 
tumor necrosis factor 
ULN 
upper limit of normal 
USADE 
unanticipated serious adverse device effect 
WOCBP 
woman of childbearing potential 
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10.11 
Appendix 11: Protocol amendment history 
The Protocol Amendment Summary of Changes Table for the current amendment is located 
directly before the Table of Contents. 
Amendment 1 (08 Feb 2023) 
Overall Rationale for the Amendment 
The original protocol dated 10 Oct 2022 was only distributed to vendors for study setup 
purposes; it was not shared with any regulatory agency. 
Section # and Name 
Description of Change 
Brief Rationale 
1.1 Synopsis 
1.2 Schema 
4.1 Overall design 
9.8 Determination of sample size 
Increased number of study 
participants to be enrolled 
Updated following discussions 
with CDE to provide sufficient 
safety exposures 
9.3 Planned efficacy/outcome 
analyses 
Deleted protocol subsection 9.3.1 
“efficacy estimands” from the 
document; subsequent subsections 
were renumbered 
Updated to be consistent with 
terminology in global pivotal 
studies 
9.3.2.1 Sensitivity analyses 
9.3.3.1 Key secondary efficacy 
endpoint analyses 
9.6 Handling of dropouts or missing 
data 
Added an additional sensitivity 
analysis for missing data 
Added additional analyses 
applicable for the increased 
sample size 
9.6 Handling of dropouts or missing 
data 
Added text to clarify planned 
sensitivity analyses 
Updated to be consistent with 
terminology in global pivotal 
studies 
5.2 Exclusion Criteria (exclusion 
criteria #7) 
Removed the term vulgaris  
Clarified the exclusion criteria 
1.1 Synopsis 
1.3 Schedule of activities 
3 Objectives and endpoints 
Added PSD (P-SIM) assessment to 
visit Week 32 and added PSD (P-
SIM) assessment over time to tertiary 
objectives and endpoints 
Updated to assess efficacy of 
bimekizumab after Q8W 
dosing 
9.7 Planned analysis and data 
monitoring 
Changed the 16-week data analysis 
and respective CSR to a 32-week 
data analysis and CSR 
Updated following discussions 
with CDE to assess efficacy of 
bimekizumab Q4W and Q8W 
dosing up to Week 32 
1.1 Synopsis 
1.2 Schema 
1.3 Schedule of activities 
4 Study design 
6.1 Treatments administered 
Replaced the 2-stage, 40-week 
Maintenance Treatment Period with a 
16-week Maintenance Treatment 
Period 
Bimekizumab treatment for 16 
weeks in the Maintenance 
Treatment Period is sufficient 
to provide evidence for 
maintained efficacy and safety  
CDE=Center for Drug Evaluation; CSR=clinical study report; PSD=patient symptom diary; P-SIM=Psoriasis 
Symptom and Impact Measure; Q4W=every 4 weeks; Q8W=every 8 weeks 
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11 
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SPONSOR DECLARATION 
I confirm that I have carefully read and understand this protocol and agree to conduct this 
clinical study as outlined in this protocol, according to Clinical Trial Regulation EU 536/2014, 
and according to current Good Clinical Practice. 
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Approval Signatures
Name:
ps0041-protocol-amend-2
Version:
1. 0
Document Number:
CLIN-000223425
Title:
PS0041 Protocol Amendment  2
Approved Date:
20 Apr 2023
Document Approvals
Approval
Verdict: Approved
Name: 
Capacity: Clinical
Date of Signature: 20-Apr-2023 00:51:19 GMT+0000
Approval
Verdict: Approved
Name: 
Capacity: Clinical
Date of Signature: 20-Apr-2023 03:25:28 GMT+0000
Approval
Verdict: Approved
Name: 
Capacity: Clinical
Date of Signature: 20-Apr-2023 06:52:42 GMT+0000
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