A Multicenter, Open-Label, Follow-Up Study to Evaluate the Long-Term Safety and Efficacy of Bimekizumab in Subjects With Psoriatic Arthritis
Phase: PHASE2
Conditions: Psoriatic Arthritis
Sponsor: UCB Biopharma SRL

UCB 
 
11 Dec 2019 
Clinical Study Protocol 
Bimekizumab 
 
PA0009 
 
 
 
Confidential 
Page 1 of 116 
PROTOCOL PA0009 AMENDMENT 3 
A MULTICENTER, OPEN-LABEL, FOLLOW-UP STUDY TO 
EVALUATE THE LONG-TERM SAFETY AND EFFICACY OF 
BIMEKIZUMAB IN SUBJECTS WITH PSORIATIC ARTHRITIS  
PHASE 2B 
 
EudraCT Number: 2017-001003-74 
IND Number: 128708 
Sponsor: 
UCB Biopharma SRL 
Allée de la Recherche 60 
1070 Brussels 
BELGIUM 
Protocol/Amendment number 
Date 
Type of 
amendment 
Final protocol 
15 May 2017 
Not applicable 
Protocol amendment 1 
27 June 2017 
Not applicable 
Protocol amendment 2 
09 Mar 2018 
Substantial 
Protocol amendment 2.1 (Czech Republic) 
11 Jun 2018 
Substantial 
Protocol amendment 3 
11 Dec 2019 
Nonsubstantial 
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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Clinical Study Protocol 
Bimekizumab 
 
PA0009 
 
 
 
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STUDY CONTACT INFORMATION 
Sponsor 
UCB BIOPHARMA SRL 
Allée de la Recherche 60 
1070 Brussels 
BELGIUM 
Sponsor Study Physician 
Name: 
, MD  
Address: 
UCB  
208 Bath Road  
Slough, SL1 3WE 
UNITED KINGDOM  
Phone: 
 
Clinical Project Manager 
Name: 
 
Address: 
UCB  
208 Bath Road 
Slough SL1 3WE 
UNITED KINGDOM 
Phone: 
 
Clinical Trial Biostatistician 
Name: 
 
Address: 
UCB  
208 Bath Road 
Slough SL1 3WE 
UNITED KINGDOM 
Phone: 
 
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Clinical Study Protocol 
Bimekizumab 
 
PA0009 
 
 
 
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Clinical Monitoring Contract Research Organization 
Name: 
PRA Health Sciences 
Address: 
4130 Park Lake Avenue, Suite 400 
Raleigh, NC 27612 
UNITED STATES 
Phone: 
+1-919-786-8200 
Fax: 
+1-919-786-8201 
SERIOUS ADVERSE EVENT REPORTING 
Serious adverse event reporting (24h) 
Fax 
Europe and Rest of the World: +32 2 386 24 21 
USA and Canada: +1 800 880 6949 or +1 866 890 3175 
Email 
Global: DS_ICT@ucb.com  
 
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Clinical Study Protocol 
Bimekizumab 
 
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TABLE OF CONTENTS 
LIST OF ABBREVIATIONS .................................................................................................... 9 
1 
SUMMARY ..................................................................................................................... 13 
2 
INTRODUCTION ........................................................................................................... 13 
2.1 Psoriatic arthritis .............................................................................................................. 13 
2.1.1 
Clinical studies ..................................................................................................... 14 
2.1.2 
Nonclinical studies ............................................................................................... 16 
3 
STUDY OBJECTIVES .................................................................................................... 16 
3.1 Primary objective ............................................................................................................. 16 
3.2 Secondary objectives ....................................................................................................... 17 
3.3 Other objectives ............................................................................................................... 17 
4 
STUDY VARIABLES ..................................................................................................... 17 
4.1 Primary variables ............................................................................................................. 17 
4.1.1 
Primary safety variables ...................................................................................... 17 
4.2 Secondary variables ......................................................................................................... 17 
4.2.1 
Secondary safety variable .................................................................................... 17 
4.2.2 
Secondary efficacy variables ............................................................................... 17 
4.3 Other variables ................................................................................................................. 17 
4.3.1 
Safety variables .................................................................................................... 17 
4.3.2 
Efficacy variables ................................................................................................ 18 
4.3.3 
PK variable .......................................................................................................... 18 
4.3.4 
Immunological variable ....................................................................................... 18 
5 
STUDY DESIGN ............................................................................................................. 18 
5.1 Study description ............................................................................................................. 18 
5.1.1 
Rescue therapy ..................................................................................................... 19 
5.1.2 
Study duration per subject ................................................................................... 19 
5.1.3 
Planned number of subjects and sites .................................................................. 19 
5.1.4 
Anticipated regions and countries ....................................................................... 19 
5.2 Schedule of study assessments ......................................................................................... 19 
5.3 Schematic diagram ........................................................................................................... 23 
5.4 Rationale for study design and selection of dose ............................................................. 23 
6 
SELECTION AND WITHDRAWAL OF SUBJECTS ................................................... 24 
6.1 Inclusion criteria .............................................................................................................. 24 
6.2 Exclusion criteria ............................................................................................................. 25 
6.3 Withdrawal criteria .......................................................................................................... 25 
6.3.1 
Potential drug-induced liver injury investigational medicinal product 
discontinuation criteria ........................................................................................ 27 
7 
STUDY TREATMENT ................................................................................................... 27 
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7.1 Description of investigational medicinal product ............................................................ 27 
7.2 Treatment to be administered ........................................................................................... 28 
7.3 Packaging ......................................................................................................................... 28 
7.4 Labeling ........................................................................................................................... 28 
7.5 Handling and storage requirements.................................................................................. 29 
7.6 Drug accountability .......................................................................................................... 29 
7.7 Procedures for monitoring subject compliance ................................................................ 30 
7.8 Concomitant medications/treatments ............................................................................... 30 
7.8.1 
Permitted concomitant treatments (medications and therapies) .......................... 30 
7.8.2 
Prohibited concomitant treatments (medications and therapies) ......................... 32 
7.9 Blinding ............................................................................................................................ 33 
7.10 Randomization and numbering of subjects ...................................................................... 33 
8 
STUDY PROCEDURES BY VISIT ............................................................................... 33 
8.1 Visit 1 ............................................................................................................................... 33 
8.2 Week 4 (Visit 2) and Week 8 (Visit 3) ............................................................................ 34 
8.3 Week 12 (Visit 4), Week 24 (Visit 5), Week 36 (Visit 6), and Week 72 (Visit 9) .......... 35 
8.4 Week 16, Week 20, Week 28, Week 32, Week 40, Week 44, Week 52, Week 56, Week 
64, Week 68, Week 76, Week 80, Week 88, and Week 92 ............................................. 36 
8.5 Week 48 (Visit 7) and Week 96 (Visit 11) ...................................................................... 36 
8.6 Week 60 (Visit 8) and Week 84 (Visit 10) ...................................................................... 37 
8.7 Week 100 (Visit 12) ......................................................................................................... 38 
8.8 Week 104 (Visit 13) or Early Termination Visit ............................................................. 39 
8.9 SFU Visit (20 weeks after the final dose of IMP) ........................................................... 40 
8.10 Early Termination Visit ................................................................................................... 40 
8.11 Unscheduled Visit ............................................................................................................ 40 
9 
ASSESSMENT OF SAFETY .......................................................................................... 41 
9.1 Adverse events ................................................................................................................. 41 
9.1.1 
Definition of AE .................................................................................................. 41 
9.1.2 
AEs of special interest ......................................................................................... 41 
9.1.3 
Other safety topics of interest .............................................................................. 42 
9.1.4 
Procedures for reporting and recording AEs ....................................................... 42 
9.1.5 
Description of AEs .............................................................................................. 42 
9.1.6 
Follow-up of AEs ................................................................................................ 43 
9.1.7 
Rule for repetition of an AE ................................................................................ 43 
9.1.8 
Pregnancy ............................................................................................................ 43 
9.1.9 
Suspected transmission of an infectious agent via a medicinal product .............. 44 
9.1.10 
Overdose of investigational medicinal product ................................................... 44 
9.1.11 
Safety signal detection ......................................................................................... 44 
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9.2 Serious AEs ...................................................................................................................... 45 
9.2.1 
Definition of SAEs .............................................................................................. 45 
9.2.2 
Procedures for reporting serious adverse events ................................................. 46 
9.2.3 
Follow-up of SAEs .............................................................................................. 46 
9.3 Immediate reporting of AEs ............................................................................................. 46 
9.4 Anticipated SAEs ............................................................................................................. 47 
9.5 Laboratory measurements ................................................................................................ 47 
9.5.1 
Evaluation of PDILI ............................................................................................ 48 
9.5.1.1 
Consultation with Medical Monitor and local hepatologist ...................... 52 
9.5.1.2 
Immediate action: determination of IMP discontinuation ......................... 52 
9.5.1.3 
IMP restart/rechallenge ............................................................................. 52 
9.5.1.4 
Testing: identification/exclusion of alternative etiology ........................... 52 
9.5.1.5 
Follow-up evaluation ................................................................................. 54 
9.6 Other safety measurements .............................................................................................. 54 
9.6.1 
Vital signs ............................................................................................................ 54 
9.6.2 
Body weight ......................................................................................................... 55 
9.6.3 
Physical examination ........................................................................................... 55 
9.6.4 
12-lead ECG ........................................................................................................ 55 
9.6.5 
Tuberculosis and TB risk factor assessment and management ........................... 55 
9.6.5.1 
Tuberculosis assessment by IGRA ............................................................ 56 
9.6.5.2 
Tuberculosis questionnaire ........................................................................ 56 
9.6.5.3 
Tuberculosis management ......................................................................... 56 
9.6.6 
Pregnancy testing ................................................................................................. 57 
9.6.7 
Assessment of suicidal ideation and behavior ..................................................... 57 
10 ASSESSMENT OF EFFICACY ...................................................................................... 57 
10.1 78/76 joint evaluation for ACR response ......................................................................... 57 
10.2 28 joint evaluation for determination of DAS28(CRP) ................................................... 58 
10.3 Patient’s Global Assessment of Disease Activity ............................................................ 58 
10.4 Physician’s Global Assessment of Disease Activity ....................................................... 58 
10.5 Patient’s Assessment of Arthritis Pain ............................................................................. 58 
10.6 Health Assessment Questionnaire-Disability Index score ............................................... 59 
10.7 CRP levels ........................................................................................................................ 59 
10.8 ACR20, ACR50, and ACR70 response ........................................................................... 59 
10.9 BSA-PSO ......................................................................................................................... 59 
10.10 
Psoriasis Area and Severity Index (PASI) ............................................................. 60 
10.11 
MDA ...................................................................................................................... 60 
10.12 
DAS28(CRP) ......................................................................................................... 61 
10.13 
MASES .................................................................................................................. 61 
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10.14 
LDI ......................................................................................................................... 61 
10.15 
Hospital Anxiety and Depression Scale ................................................................. 61 
10.16 
PsAID-9 ................................................................................................................. 62 
10.17 
SF-36 ...................................................................................................................... 62 
11 ASSESSMENT OF IMMUNOGENICITY ..................................................................... 62 
12 STUDY MANAGEMENT AND ADMINISTRATION ................................................. 62 
12.1 Adherence to protocol ...................................................................................................... 62 
12.2 Monitoring ....................................................................................................................... 63 
12.2.1 
Definition of source data ..................................................................................... 63 
12.2.2 
Source data verification ....................................................................................... 63 
12.3 Data handling ................................................................................................................... 64 
12.3.1 
Case Report form completion .............................................................................. 64 
12.3.2 
Database entry and reconciliation ........................................................................ 64 
12.3.3 
Subject Screening and Enrollment log/Subject Identification Code list.............. 64 
12.4 Termination of the study .................................................................................................. 65 
12.5 Archiving and data retention ............................................................................................ 65 
12.6 Audit and inspection ........................................................................................................ 65 
12.7 Good Clinical Practice ..................................................................................................... 66 
13 STATISTICS ................................................................................................................... 66 
13.1 Definition of analysis sets ................................................................................................ 66 
13.2 General statistical considerations ..................................................................................... 66 
13.3 Planned safety analyses .................................................................................................... 66 
13.3.1 
Safety analyses ..................................................................................................... 66 
13.4 Planned efficacy analyses ................................................................................................ 67 
13.4.1 
Subgroup analysis ................................................................................................ 67 
13.5 Planned immunogenicity analyses ................................................................................... 67 
13.6 Other analyses .................................................................................................................. 68 
13.7 Handling of protocol deviations ....................................................................................... 68 
13.8 Handling of dropouts or missing data .............................................................................. 68 
13.9 Planned interim analysis and data monitoring ................................................................. 68 
13.10 
Determination of sample size ................................................................................. 68 
14 ETHICS AND REGULATORY REQUIREMENTS ...................................................... 68 
14.1 Informed consent ............................................................................................................. 68 
14.2 Subject identification cards .............................................................................................. 69 
14.3 Institutional Review Boards and Independent Ethics Committees .................................. 69 
14.4 Subject privacy ................................................................................................................. 70 
14.5 Protocol amendments ....................................................................................................... 70 
15 FINANCE, INSURANCE, AND PUBLICATION ......................................................... 70 
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16 REFERENCES ................................................................................................................ 71 
17 APPENDICES ................................................................................................................. 75 
17.1 Markedly abnormal laboratory values ............................................................................. 75 
17.2 Protocol Amendment 1 .................................................................................................... 76 
17.3 Protocol Amendment 2 .................................................................................................... 79 
17.4 Protocol Amendment 3 .................................................................................................... 96 
18 DECLARATION AND SIGNATURE OF INVESTIGATOR ..................................... 115 
19 SPONSOR DECLARATION ........................................................................................ 116 
 
LIST OF TABLES 
Table 5‒1: 
Schedule of study assessments......................................................................... 20 
Table 7-1: 
Prohibited or restricted medications ................................................................ 32 
Table 7-2: 
Additional prohibited psoriasis treatments ...................................................... 32 
Table 9‒1: 
Anticipated SAEs for the population of subjects with psoriatic arthritis ......... 47 
Table 9-2: 
Laboratory measurements ................................................................................ 48 
Table 9-3: 
Required investigations and follow-up for PDILI ........................................... 50 
Table 9‒4: 
PDILI laboratory measurements ...................................................................... 53 
Table 9‒5: 
PDILI information to be collected ................................................................... 54 
Table 10‒1: 
Swelling and tenderness grading ..................................................................... 58 
Table 10‒2: 
Body areas for calculation of percent BSA for PASI ...................................... 60 
Table 10‒3: 
MDA criteria in PsA ........................................................................................ 61 
Table 17-1: 
Definitions of markedly abnormal hematology values .................................... 75 
Table 17‒2: 
Definitions of markedly abnormal biochemistry values .................................. 75 
 
LIST OF FIGURES 
Figure 5‒1: 
Schematic diagram ........................................................................................... 23 
 
 
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LIST OF ABBREVIATIONS 
ACR 
American College of Rheumatology 
ACR20, 50, 70 
American College of Rheumatology 20, 50, 70% response criteria 
AE  
adverse event 
AESI 
adverse event of special interest 
ALP 
alkaline phosphatase 
ALT 
alanine aminotransferase 
AS 
ankylosing spondylitis 
AST 
aspartate aminotransferase 
axSpA 
axial spondyloarthritis 
BP 
blood pressure 
BSA 
body surface area 
CD 
cluster of differentiation 
CDMS 
clinical data management system 
CHO 
Chinese Hamster Ovarian 
CI 
confidence interval 
COX-2 
cyclooxygenase-2 
CPM 
Clinical Project Manager 
CRO 
Contract Research Organization 
CRP 
C-reactive protein 
DAS28(CRP) 
Disease Activity Score-28 joint count C-reactive protein 
DMARD 
disease-modifying antirheumatic drug 
EAER 
exposure-adjusted event rate 
EAIR 
exposure-adjusted incidence rate 
ECG 
electrocardiogram 
eCRF 
electronic Case Report form 
eC-SSRS 
electronic Columbia-Suicide Severity Rating Scale 
EDC 
electronic data capture 
ES 
Enrolled Set 
ET 
Early Termination 
FAS 
Full Analysis Set 
FDA 
Food and Drug Administration 
GCP 
Good Clinical Practice 
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GI 
gastrointestinal 
GMP 
Good Manufacturing Practice 
HADS 
Hospital Anxiety and Depression Scale 
HADS-A 
Hospital Anxiety and Depression Scale—Anxiety  
HADS-D 
Hospital Anxiety and Depression Scale—Depression  
HAQ-DI 
Health Assessment Questionnaire—Disability Index 
HRQoL 
Health-Related Quality of Life 
IB 
Investigator’s Brochure 
IBD 
Inflammatory Bowel Disease 
ICH 
International Council for Harmonisation 
IEC 
Independent Ethics Committee 
IgG 
Immunoglobulin G 
IGRA 
interferon-gamma release assay 
IL 
interleukin 
IL-17-RA 
interleukin-17 receptor A 
IMP 
investigational medicinal product 
IP 
interphalangeal 
IRB 
Institutional Review Board 
IUD 
intrauterine device  
IUS 
intrauterine hormone-releasing system 
iv 
intravenous 
IXRS 
interactive web or voice response system  
LDI 
Leeds Dactylitis Index 
LTB 
latent tuberculosis 
MAb 
monoclonal antibody 
MASES 
Maastricht Ankylosing Spondylitis Enthesitis Index 
MCMC 
Markov Chain Monte Carlo 
MCP 
metacarpophalangeal 
MDA 
Minimal Disease Activity 
MedDRA 
Medical Dictionary for Regulatory Activities 
MI 
multiple imputation 
NOAEL 
no adverse effect level 
NRI 
nonresponder imputation 
NSAID 
nonsteroidal anti-inflammatory drug 
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NTMB 
nontuberculous mycobacteria 
OLE 
open-label extension 
PASI 
Psoriasis Area and Severity Index 
PASI75, PASI90, 
PASI100 
Psoriasis Area and Severity Index 75%, 90%, 100% 
PD 
pharmacodynamics 
PDILI 
potential drug-induced liver injury 
PFS 
prefilled syringe 
PGADA 
Patient’s Global Assessment of Disease Activity 
PhGADA 
Physician’s Global Assessment of Disease Activity 
PIP 
proximal interphalangeal 
PK 
pharmacokinetics 
PS 
Patient Safety 
PsA 
psoriatic arthritis 
PsAID-9 
Psoriatic Arthritis Impact of Disease-9 
PSO 
psoriasis 
PtAAP 
Patient’s Assessment of Arthritis Pain 
PUVA 
psoralen plus ultraviolet A light therapy 
Q4W 
every 4 weeks (monthly) 
RA 
rheumatoid arthritis 
RCTC 
Rheumatology Common Toxicity Criteria 
SAE 
serious adverse event 
sc 
subcutaneous(ly) 
SF-36 
Short-Form 36-item Health Survey 
SFU 
Safety Follow-up 
SJC 
swollen joint count 
SOP 
Standard Operating Procedure 
SS 
Safety Set 
t1/2 
half-life 
TEAE 
treatment-emergent adverse event 
TB 
tuberculosis 
Th17 
T helper 17 
TJC 
tender joint count 
TNF 
tumor necrosis factor 
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TNFα 
tumor necrosis factor-alpha 
ULN 
upper limit of normal 
UVA 
ultraviolet A 
VAS 
visual analog scale 
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1 
SUMMARY 
PA0009 is a multicenter, open-label extension (OLE) study evaluating the long-term safety, 
tolerability, and efficacy of bimekizumab in subjects with psoriatic arthritis (PsA). Only subjects 
who complete PA0008, a Phase 2b study are eligible for enrollment into PA0009. At Week 48 of 
PA0008, all subjects continuing into PA0009 will undergo the final PA0008 study assessments 
and any nonoverlapping PA0009 entry assessments and will then receive their first open-label 
dose of bimekizumab. 
PA0008 is a multicenter, Phase 2b, randomized, double-blind, placebo-controlled, 
parallel-group, dose-ranging study to evaluate the efficacy and safety of bimekizumab in 
200 subjects with active PsA.  
In the PA0009 OLE study, bimekizumab will be administered at a dose of 160mg every 4 weeks 
(Q4W) subcutaneously (sc) for all subjects regardless of treatment received in PA0008. 
Up to 200 subjects from PA0008 may be enrolled into this study at any of the sites participating 
in PA0008. 
The primary objective of PA0009 is to assess the long-term safety and tolerability of 
bimekizumab administered over a period of up to 100 weeks (~2 years). The primary safety 
variables are the incidences of treatment-emergent adverse events (TEAEs) and 
treatment-emergent serious adverse events (SAEs). 
The secondary objective is to assess the long-term efficacy of bimekizumab over a period of up 
to 104 weeks (~2 years). The secondary efficacy variables include the American College of 
Rheumatology 20% (ACR20) response at Week 48 (with a responder defined as a subject with 
an improvement from PA0008 Baseline of ≥20% in the swollen and tender joint counts and at 
least 3 of the other 5 components of the core set of American College of Rheumatology [ACR] 
response measures), American College of Rheumatology 50% (ACR50) response at Week 48; 
American College of Rheumatology 70% (ACR70) response at Week 48, change from PA0008 
Baseline in the Maastricht Ankylosing Spondylitis Enthesitis Index (MASES) at Week 48, 
change from PA0008 Baseline in the Leeds Dactylitis Index (LDI) at Week 48, the Psoriasis 
Area and Severity Index 75 (PASI75) response, and the Psoriasis Area and Severity Index 90 
(PASI90) response at Week 48. The secondary safety variable is the withdrawal due to TEAEs.  
Other objectives are to evaluate the impact on dactylitis, enthesitis, and patient-reported quality 
of life, and to assess the plasma concentrations and immunogenicity of bimekizumab.  
The study duration for each subject is estimated to be up to a maximum of 120 weeks: an 
Open-Label Treatment Period of up to 100 weeks (~2 years), followed by a Safety Follow-up 
(SFU) Visit 20 weeks after the final dose of bimekizumab. 
2 
INTRODUCTION 
2.1 
Psoriatic arthritis 
Psoriatic arthritis, a chronic inflammatory musculoskeletal disorder, occurs in approximately 6% 
to 41% of people affected by psoriasis (PSO) (Ogdie and Weiss, 2015). A substantial proportion 
of subjects have polyarthritis (McHugh et al, 2003). Disease-modifying antirheumatic drugs 
(DMARDs) and biological agents targeting tumor necrosis factor-alpha (TNFα), 
interleukin (IL)-17, and IL-12/23 are effective in PsA (Kavanaugh et al, 2012; 
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Kavanaugh et al, 2009; Gottlieb et al, 2009; Gladman et al, 2007; Genovese et al, 2007; 
Kavanaugh et al, 2006; Antoni et al, 2005a; Antoni et al, 2005b; Mease et al, 2005; 
Mease et al, 2004, McInnes et al, 2015; Mease et al, 2015). However, some subjects are not 
responsive to these treatments, do not maintain a clinical response (defined as achieving ACR20 
response criteria), or have contraindications or intolerance to these agents. 
Recent work has implicated various isoforms comprising the IL-17 cytokine family in the 
pathophysiology of PSO and of PsA (Raychaudhuri et al, 2012; Fujishima et al, 2010; 
Watanabe et al, 2009; Harper et al, 2009; Johansen et al, 2009). Numbers of IL-17A positive 
cells are increased and localized in psoriatic skin lesions (Fujishima et al, 2010; 
Watanabe et al, 2009; Harper et al, 2009; Johansen et al, 2009), and IL-17A and IL-17F are 
overexpressed in the serum and skin lesions of subjects with PSO (Johansen et al, 2009), while 
IL-17F in particular is a key inflammatory cytokine contributing to PSO pathology 
(Fujishima et al, 2010; Watanabe et al, 2009). Cluster of differentiation (CD) 4 + T helper 
17 (Th17) cells, IL-17A, and IL-17 receptor A (IL-17-RA) have recently been shown to play a 
role in PsA (Raychaudhuri et al, 2012). Anti-IL-17 antibodies have been shown to be effective 
treatments for PSO (Papp et al, 2012; Leonardi et al, 2012; Hueber et al, 2010) and have also 
shown activity in subjects with rheumatoid arthritis (RA), PsA, and ankylosing spondylitis (AS) 
(McInnes et al, 2014; Mease et al, 2015; Hueber et al, 2010; Genovese et al, 2010). Taken 
together these data suggest that inhibition of both IL-17A and IL-17F could be therapeutically 
effective in subjects with PSO, PsA, and axial spondyloarthritis (axSpA). 
Bimekizumab (UCB4940) is an engineered, humanized full-length monoclonal antibody (mAb) 
of immunoglobulin (IgG) 1 subclass of approximately 150,000 Dalton which is expressed in a 
genetically engineered Chinese Hamster Ovarian (CHO) cell line. Bimekizumab has high affinity 
for human IL-17A and human IL-17F and selectively and potently inhibits the activity of both 
isoforms in vitro. Therefore, it 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. 
2.1.1 
Clinical studies 
Four clinical studies of bimekizumab have been completed: UP0008 in 39 subjects with 
mild-to-moderate plaque PSO, RA0124 in 30 healthy volunteers, UP0031 in 12 healthy 
volunteers, and PA0007 in 53 subjects with PsA.  
UP0008 was a Phase 1, single ascending dose study in adults with mild-to-moderate PSO 
affecting ≤5% body surface area (BSA). In this blinded study, single doses of up to 640mg 
(approximately 8mg/kg in an 80kg adult) were evaluated. A total of 26 subjects with PSO with 
<5% of body surface involvement were treated with a range of single intravenous (iv) doses from 
8 to 640mg. The pharmacokinetics (PK) of bimekizumab was linear in the tested dose range. 
There were no clinically relevant safety findings identified at any dose and all doses were well 
tolerated. The prespecified exploratory assessment of disease activity showed clinically relevant 
and statistically significant improvements at the higher doses studied. 
RA0124 was a Phase 1, open-label, parallel-group, single-dose study in healthy subjects. The 
primary objective of this study was to determine the absolute bioavailability of single sc doses of 
bimekizumab (80 and 160mg). The secondary objectives were to evaluate the dose 
proportionality of bimekizumab 80 and 160mg sc and to evaluate the safety and tolerability of 
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these sc doses and 160mg given by iv infusion. In RA0124, the absolute bioavailability was 
similar for the 2 doses tested (0.656 and 0.631 for the bimekizumab 80mg and 160mg sc doses, 
respectively). The median half-life (t1/2) following sc administration was similar to that following 
iv administration (27.81 days and 28.25 days for bimekizumab 160mg sc and bimekizumab 
160mg iv, respectively). 
An additional Phase 1 study, UP0031, evaluated the relative bioavailability and safety and 
tolerability of 2 bimekizumab formulations (a 
-based formulation 2x80mg and an 
-based formulation 1x160mg) administered by sc injection to healthy volunteers. Results 
show similar geometric means for AUC between the 2 bimekizumab formulations 
(2x80mg=653.8day*μg/mL; 1x160mg=628.3day*μg/mL) and the relative bioavailability for the 
bimekizumab 1x160mg versus 2x80mg formulations was calculated as 96.1% with a 
95% confidence interval (CI): 72.7, 127.0. The wide 95% CI was expected due to the small 
sample size in UP0031. 
Bimekizumab has also been investigated in a Phase 1b, proof-of-concept, randomized, 
placebo-controlled, multiple-dose study (PA0007). A total of 53 subjects have been randomized. 
The primary objective of PA0007 was to assess the safety and PK of multiple dose 
administration of iv bimekizumab in subjects with PsA. Four active doses and a placebo were 
tested. Drug was administered as a loading dose of bimekizumab 80, 160, 240, or 560mg at 
Week 1, and 2 additional doses of bimekizumab 40, 80, 160, or 320mg at Week 4 and Week 7. 
In each treatment group, subjects received a total of 3 doses of bimekizumab, administered every 
3 weeks. There were no unexpected clinically relevant safety findings and all doses were well 
tolerated. The PK was linear across the tested dose range and no change in PK was observed 
following multiple doses. Observed changes in inflammatory biomarkers were consistent with 
expectations based on the IL-17A and IL-17F mechanism of action. The exploratory analysis 
showed clinically relevant improvement in activity of PsA and in skin involvement in those 
subjects with concomitant active psoriatic lesions. Data from the top 3 bimekizumab dose groups 
pooled showed that, by Week 9, 80% (95% confidence interval [CI]: 62.7, 90.5) of subjects 
achieved an ACR20 response (vs 16.7% [95% CI: 4.7, 44.8] in the placebo group) and 100% 
(95% CI: 79.6, 100.0) of 26 subjects with active psoriatic lesions had achieved a PASI75 
response (vs 0% [95% CI: 0.0, 43.4] in the placebo group). 
Infections (mostly nasopharyngitis) were the most commonly reported events in both the 
active-treatment and the placebo group. None of the infections were considered serious or 
required treatment with antibiotics. Two subjects in the active-treatment group experienced 
1 local candida infection each (oropharyngitis and vulvovaginitis) that were nonserious and 
resolved with topical therapy. There was a reduction in mean neutrophil count in the 
active-treatment group, although this drop was not clinically relevant and a clear relationship 
with dose or time was not evident. Some increases in liver function tests were reported, but none 
had a convincing relationship to exposure to study medication. 
In the bimekizumab clinical studies to date, the most commonly reported gastrointestinal (GI) 
adverse events (AEs) were abdominal distension, abdominal pain, diarrhea, flatulence, nausea, 
and vomiting. All of these events, except 1 event of vomiting, were mild or moderate in 
intensity. T helper-17 and other IL-17-producing cell types are present in a high frequency in the 
physiologic, healthy state of the intestinal mucosa. Interleukin-17 is recognized as an important 
player in the pathophysiology of infectious and immune-mediated GI diseases and has been 
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shown to contribute to the gut barrier function (Ivanov et al, 2008). Clinical data with 
secukinumab suggest that the drug may worsen symptoms of coexisting Crohn’s disease in 
patients with psoriasis and ankylosing spondylitis (Baeten et al, 2015). 
Several additional studies of bimekizumab are ongoing. RA0123 is a Phase 2a, double-blind, 
randomized, placebo-controlled, multiple dose study to evaluate the safety, PK, 
pharmacodynamics (PD), and efficacy of multiple doses of bimekizumab administered as add-on 
therapy to stable certolizumab pegol (Cimzia®) therapy in subjects with moderate to severe RA. 
UC0011 is a Phase 2 study, which will evaluate the efficacy, safety, tolerability, and PK of an iv 
loading dose and 2 sc maintenance doses of bimekizumab in subjects with moderate to severe 
active ulcerative colitis. PS0010, PS0011, PS0016, and PS0018 are Phase 2 studies, which will 
evaluate the PD, PK, safety, and/or efficacy of bimekizumab administered sc to subjects with 
PSO. AS0008 is a Phase 2, double-blind, randomized, placebo-controlled, multiple-dose study to 
evaluate the efficacy and safety of bimekizumab in subjects with active AS. 
A Phase 2b dose-ranging study (PA0008) was designed to investigate the dose-response 
relationship, efficacy and safety of various bimekizumab dose regimens in subjects with active 
PsA. The current Phase 2b OLE study (PA0009) will allow access to bimekizumab for subjects 
who completed the lead-in study PA0008, while allowing the collection of further data on the 
long-term safety and efficacy of bimekizumab in this subject population.  
Additional information on the clinical data for bimekizumab is available in the current version of 
the Investigator’s Brochure (IB). 
2.1.2 
Nonclinical studies 
Parallel inhibition of IL-17A and IL-17F has shown potent effects in a variety of animal models 
of inflammatory disease. Intravenously administered bimekizumab was well tolerated in repeat 
dose toxicology studies in Cynomolgus monkeys with a no adverse effect level (NOAEL) of 
200mg/kg/week. The findings of note in toxicity studies were diarrhea related to infectious 
enteritis (observed in the single dose study) and asymptomatic mild colonic ulceration in a 
proportion of animals (in the repeat-dose study); this latter finding was not associated with 
hematology abnormalities. Data suggest that bimekizumab has induced primary lesions to the 
mucosa-associated lymphoid tissue via a pharmacologically related mechanism. In a second 
repeat-dose study, none of the minor apoptosis/necrosis findings observed in gut associated 
lymph nodes were seen. In animals given the highest dose of bimekizumab in the study 
(20mg/kg/week), a slightly higher number of protozoa (Balantidium coli) was observed in the 
cecum and colon as compared to the control animals and low dose animals. Therefore, gut 
associated lymph node lesions observed in the first study are considered to be accidental and/or 
linked to exaggerated pharmacology and proliferation of Balantidium coli and are considered the 
result of a change in local mucosal immunity.  
Additional information on the nonclinical data for bimekizumab is available in the current 
version of the IB. 
3 
STUDY OBJECTIVES 
3.1 
Primary objective 
The primary objective of this open-label study is to assess the long-term safety and tolerability of 
bimekizumab administered over a period of up to 100 weeks (~2 years). 
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3.2 
Secondary objectives 
The secondary objectives of the study are as follows: 
 To assess the long-term efficacy of bimekizumab  
3.3 
Other objectives 
The other objectives are: 
 To assess the impact on dactylitis and enthesitis 
 To assess the impact on patient-reported quality of life  
 To assess plasma concentrations of bimekizumab 
 To assess the immunogenicity of bimekizumab 
4 
STUDY VARIABLES 
All efficacy variables will be analyzed relative to the Baseline Visit of PA0008. Safety variables 
measured at the start of PA0009 will be referred to as PA0009 entry values. 
4.1 
Primary variables 
4.1.1 
Primary safety variables 
The primary safety variables are the incidences of TEAEs and treatment-emergent SAEs. 
4.2 
Secondary variables 
4.2.1 
Secondary safety variable 
The secondary safety variable is the withdrawal due to TEAEs. 
4.2.2 
Secondary efficacy variables 
The secondary efficacy variables are:  
 ACR20, ACR50, and ACR70 response at Week 48 
 Change from Baseline of PA0008 in MASES at Week 48 
 Change from Baseline of PA0008 in the LDI at Week 48 
 PASI75 and PASI90 response at Week 48 
4.3 
Other variables 
4.3.1 
Safety variables 
Other safety variables are listed below. 
 
Change from PA0009 Laboratory Baseline (defined as the earliest date in PA0009 at or prior 
to PA0009 Week 12) for clinical laboratory variables (hematology and biochemistry, 
excepting high-sensitivity C-reactive protein [CRP]) at each visit)  
 
Change from Baseline of PA0008 in vital signs (pulse, temperature, and blood pressure) and 
body weight 
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4.3.2 
Efficacy variables 
Other efficacy variables are listed below and will be evaluated at scheduled visits in accordance 
with the schedule of study assessments in Table 5‒1. 
 ACR20, ACR50, and ACR70 response  
 PASI75, PASI90, and PASI100 response 
 Minimal Disease Activity (MDA) as defined in Table 10‒3 
 Change from Baseline of PA0008 in the Disease Activity Score-28 based on C-reactive 
protein (DAS28[CRP]) by visit 
 Change from Baseline of PA0008 in MASES 
 Change from Baseline of PA0008 in the LDI 
 Change from Baseline of PA0008 in Psoriatic Arthritis Impact of Disease (PsAID)-9 
 Change from Baseline of PA0008 in Short Form 36-item Health Survey (SF-36) 
 Change from Baseline of PA0008 in the Hospital Anxiety and Depression Scale (HADS): 
HADS-Anxiety (HADS-A) and HADS-Depression (HADS-D) scores 
 Depression and anxiety status “normal” as defined by HADS-D and HADS-A <8 
4.3.3 
PK variable 
The PK variable is the plasma concentration of bimekizumab evaluated at scheduled visits up to 
104 weeks (2 years) in accordance with the schedule of study assessments in Table 5‒1. 
4.3.4 
Immunological variable 
The immunological variable is the anti-bimekizumab antibody detection evaluated at scheduled 
visits up to 104 weeks (2 years) in accordance with the schedule of study assessments in 
Table 5‒1. 
5 
STUDY DESIGN 
5.1 
Study description 
PA0009 is a multicenter OLE study to assess the long-term safety, tolerability, and efficacy of 
bimekizumab in eligible adult subjects with PsA who completed the Phase 2b study PA0008. At 
Week 48 of PA0008, all eligible subjects continuing into PA0009 will undergo their final 
PA0008 study assessments and any nonoverlapping PA0009 entry assessments and will then 
receive their first open-label dose of bimekizumab. 
The OLE study will assess the safety, tolerability, and efficacy of bimekizumab for a period of 
up to 100 weeks (~2 years). Bimekizumab will be administered at a dose of 160mg Q4W upon 
entry into PA0009, regardless of the dose received in PA0008.  
Additionally, as described in (Section 5.1.1), other treatments may be used in addition to 
bimekizumab per Investigator discretion. Subjects not responding to treatment may be 
withdrawn from the treatment and study at the discretion of the Investigator. 
A schedule of study assessments is presented in Table 5‒1. 
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A study schematic diagram of PA0009 is presented in Figure 5‒1. 
5.1.1 
Rescue therapy 
In this OLE study, some subjects may require additional treatment in addition to medications 
received during PA0008 to control their PsA symptoms. The decision to implement such therapy 
will be at the discretion of the Investigator. Therapies that are permitted for their disease within 
the context of the study are provided in Section 7.8.1 (Permitted concomitant treatments). 
Concomitant medication that is currently not considered safe or best medical practice should be 
avoided. See Section 7.8.2 for medications that are specifically prohibited. 
5.1.2 
Study duration per subject 
The study duration for each subject is estimated to be up to a maximum of 120 weeks: 
 Open-Label Treatment Period: up to 100 weeks (~2 years) 
 SFU Visit: 20 weeks after the final dose of bimekizumab 
The subject may remain in the study until the study ends after 120 weeks, until the Sponsor 
decides to close the study, or until bimekizumab development is stopped by the Sponsor, 
whichever comes first. The Sponsor may consider transitioning the subject into another 
bimekizumab study or program. 
The end of the study is defined as the date of the last visit of the last subject in the study. 
5.1.3 
Planned number of subjects and sites 
Up to 200 subjects from the ongoing PA0008 Phase 2b study could be enrolled into this study at 
any of the sites participating in PA0008. 
5.1.4 
Anticipated regions and countries 
The regions planned for study conduct are the same as in PA0008 (Europe and North America).  
5.2 
Schedule of study assessments 
A schedule of study assessments is provided in Table 5‒1. 
 
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Table 5‒1: 
Schedule of study assessments 
Protocol activity 
Treatment Period 
 
SFU 
Weeksa 
EVb 
4 
12 
16 
24 
28 
36 
40 
48 
52 
60 
64 
72 
76 
84 
88 
96 
100 
W104/ 
- 
 
 
8 
 
20 
 
32 
 
44 
 
56 
 
68 
 
80 
 
92 
 
 
ET 
 
Visita 
1 
2/3 
4 
Hc 
5 
Hc 
6 
Hc 
7 
Hc 
8 
Hc 
9 
Hc 
10 
Hc 
11 
12 
13 
 
Informed consent 
Xd 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Inclusion/exclusion 
Xe 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Concomitant medications 
Xf 
X 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Adverse events 
Xf 
X 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
eC-SSRS 
Xe,f 
X 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
HADS 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
HAQ-DI 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
SF-36 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
PGADA 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
PtAAP 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
PsAID-9 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
TB questionnaire 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Vital signs (pulse, 
temperature, BP)g 
Xe 
X 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Body weight 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Physical examinationh 
Xe,f 
 
 
 
 
 
 
 
X 
 
 
 
 
 
 
 
X 
 
X 
X 
TJC (78) and SJC (76) 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
BSA affected by PSO (BSA 
palm method) 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
PASIi 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
MASES 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
 
 
X 
 
 
 
X 
 
X 
 
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Table 5‒1: 
Schedule of study assessments 
Protocol activity 
Treatment Period 
 
SFU 
Weeksa 
EVb 
4 
12 
16 
24 
28 
36 
40 
48 
52 
60 
64 
72 
76 
84 
88 
96 
100 
W104/ 
- 
 
 
8 
 
20 
 
32 
 
44 
 
56 
 
68 
 
80 
 
92 
 
 
ET 
 
Visita 
1 
2/3 
4 
Hc 
5 
Hc 
6 
Hc 
7 
Hc 
8 
Hc 
9 
Hc 
10 
Hc 
11 
12 
13 
 
LDI 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
PhGADA 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
 
ECG 
Xe,f 
 
 
 
 
 
 
 
X 
 
 
 
 
 
 
 
X 
 
X 
 
Hematology/biochemistry/ 
urine pregnancyj,k 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Blood Sample for CRPk 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Blood sample for 
bimekizumab plasma 
concentrationsk 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
 
 
X 
 
 
 
X 
 
X 
X 
Blood sample for anti-
bimekizumab antibodiesk 
Xe,f 
 
X 
 
X 
 
X 
 
X 
 
 
 
X 
 
 
 
X 
 
X 
X 
IGRA TB testl 
Xe 
 
 
 
 
 
 
 
X 
 
 
 
 
 
 
 
X 
 
 
X 
IXRS  
X 
X 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
 
X 
X 
X 
X 
Bimekizumab 
administration 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
 
 
BP=blood pressure; BSA=body surface area; CRP=C-reactive protein; eC-SSRS=electronic Columbia-Suicide Severity Rating Scale; 
ECG=electrocardiogram; ET=Early Termination; EV=Entry Visit; H=home; HADS=Hospital Anxiety and Depression Scale; HAQ-DI=Health Assessment 
Questionnaire—Disability Index; IGRA=interferon-gamma release assay; IXRS=interactive voice or web response system; LDI=Leeds Dactylitis Index; 
MASES= Maastricht Ankylosing Spondylitis Enthesitis Score; PASI=psoriasis area severity index; PGADA=Patient’s Global Assessment of Disease 
Activity; PhGADA=Physician’s Global Assessment of Disease Activity; PsAID=Psoriatic Arthritis Impact of Disease; PSO=psoriasis; PtAAP=Patient’s 
Assessment of Arthritis Pain; SF-36=Short Form 36-item Health Survey; SFU=Safety Follow-Up; SJC=swollen joint count; TB=tuberculosis; TJC=tender 
joint count 
Note: The SFU Visit will occur 20 weeks after the final dose of study medication. 
a Visit windows are ±7 days from the scheduled visit day (relative to the first dose) with a minimum of 21 days and a maximum of 35 days in between doses 
at all visits except the SFU Visit. For the SFU Visit (20 weeks after the final dose), the visit should occur no more than 3 days prior to the scheduled visit 
date and within 7 days after the scheduled visit date (-3 days/+7 days). 
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Table 5‒1: 
Schedule of study assessments 
Protocol activity 
Treatment Period 
 
SFU 
Weeksa 
EVb 
4 
12 
16 
24 
28 
36 
40 
48 
52 
60 
64 
72 
76 
84 
88 
96 
100 
W104/ 
- 
 
 
8 
 
20 
 
32 
 
44 
 
56 
 
68 
 
80 
 
92 
 
 
ET 
 
Visita 
1 
2/3 
4 
Hc 
5 
Hc 
6 
Hc 
7 
Hc 
8 
Hc 
9 
Hc 
10 
Hc 
11 
12 
13 
 
b PA0009 entry will occur at the end of the lead-study PA0008. At Week 48 of PA0008, all subjects continuing into PA0009 will undergo the final 
PA0008 study assessments and any nonoverlapping PA0009 entry assessments before receiving their first open-label dose of bimekizumab. 
c From the Entry Visit onwards, self-administration training will be provided to the subject/caregivers/appropriate designee by the study nurse. At Week 8 
and Week 12, the subject/caregiver/appropriate designee will perform administrations under the supervision of the site staff to ensure that study medication is 
being properly and safely injected. 
d Ensure that a separate Informed Consent form was completed by the subject for PA0009 prior to study entry. 
e To be performed prior to the first dose of open-label bimekizumab. 
f Assessment will be performed at Week 48 of the lead-in study PA0008 and will be used as the PA0009 entry value. 
g At PA0009 study entry collect pulse and BP prior to drug administration and then at 30 minutes and 1 hour after dosing. At all other visits collect pulse and 
BP prior to drug administration and once after dosing.  
h Includes evaluation of signs and symptoms of active TB and risk for exposure to TB. 
i If the BSA affected by PSO was ≥3% at Baseline of PA0008, determine the PASI. 
j If there has been a delay in menses, perform a urine pregnancy test. 
k All blood samples are to be taken prior to dosing. 
l It is recommended that the QuantiFERON TB Test be performed. This assessment will be performed at study entry, unless an IGRA negative result is 
available from less than 6 weeks prior to the first dose of open-label bimekizumab. 
 
 
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5.3 
Schematic diagram 
A study schematic diagram of PA0009 is provided in Figure 5‒1. 
Figure 5‒1: Schematic diagram 
 
IMP=investigational medicinal product; Q4W=every 4 weeks; sc=subcutaneous; SFU=Safety Follow-up 
Note: Self-administration will be allowed after 3 months of treatment (from Week 16 onwards) as described in 
Table 5‒1.  
Note: Additionally, as described in (Section 5.1.1 and Section 7.8.1), other treatments may be used in addition to 
bimekizumab per Investigator discretion. Subjects not responding to treatment may be withdrawn from the study at 
the discretion of the Investigator. 
a Subjects will receive their final dose of study drug on Week 100 and the SFU Visit will be conducted 20 weeks 
after the last dose of IMP. 
5.4 
Rationale for study design and selection of dose 
A dose of 160mg Q4W was selected based on the current understanding of PK/PD of 
bimekizumab in PsA (data from PA0007). Based on this analysis, a dose of 160mg Q4W is 
expected to provide an optimal response in most of the subjects. Based on the modeling 
outcome, UCB expects that the ACR50 response would maximize at 160mg Q4W, and hence, 
this dose was selected for PA0009.  
A bimekizumab dose of 160mg Q4W is currently being used in ongoing Phase 2b clinical 
studies.  
Doses greater than 160mg have been previously studied in the development of bimekizumab. In 
the single ascending dose study, UP0008, a single dose of bimekizumab 640mg was tested. In 
the multiple dose study, PA0007, a bimekizumab 560mg loading dose followed by 2 subsequent 
320mg doses every 3 weeks was tested. At exposure levels achieved at these doses, the 
compound had no significant safety concerns. In the previous clinical studies, bimekizumab was 
administered iv and in the current study bimekizumab will be administered sc (bioavailability of 
bimekizumab is 64%). Due to lower bioavailability, bimekizumab exposure is expected to be 
lower with sc administration compared with after iv administration, therefore, the dose regimens 
are expected to be 
  
As more data for bimekizumab become available in this indication, doses and dosing regimen 
may be modified accordingly. 
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6 
SELECTION AND WITHDRAWAL OF SUBJECTS 
6.1 
Inclusion criteria 
To be eligible to participate in this study, all of the following criteria must be met: 
1a. An Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved written 
Informed Consent form is signed and dated by the subject.  
2a. Subject is considered reliable and capable of adhering to the protocol (eg, able to understand 
and complete questionnaires), visit schedule, or medication intake according to the judgment 
of the Investigator. 
3. In the opinion of the Investigator, the subject is expected to benefit from participation in an 
OLE study. 
4. Subject completed PA0008 without meeting any withdrawal criteria. 
5. Female subjects must be postmenopausal (at least 1 year), 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 until 20 weeks after last administration of study 
medication, and have a negative pregnancy test at the last visit of PA0008. 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 (IUD) 
 intrauterine hormone-releasing system (IUS) 
 bilateral tubal occlusion 
 vasectomized partner  
 sexual abstinence if it is in accordance with a subject’s preferred and common lifestyle. 
Subjects who use abstinence as a form of birth control must agree to abstain from 
heterosexual intercourse until 20 weeks after the last dose of IMP. Study personnel must 
confirm the continued use of abstinence is still in accordance with the subject’s lifestyle 
at regular intervals during the study. 
Male subjects with a partner of childbearing potential must be willing to use a condom when 
sexually active, up until 20 weeks after the last administration of study medication 
(anticipated 5 half-lives). 
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6.2 
Exclusion criteria 
Subjects are not permitted to enroll in the study if any of the following criteria are met: 
1. Female subjects who plan to become pregnant during the study or within 20 weeks following 
last dose of study medication. Male subjects who are planning a partner pregnancy during the 
study or within 20 weeks following the last dose. 
2. Subjects with any current sign or symptom that may indicate a medically significant active 
infection (except for the common cold) or has had an infection requiring systemic antibiotics 
within 2 weeks of study entry. The medical monitor must be consulted prior to subject’s 
entry into PA0009 in such cases.  
3. Subjects who meet any withdrawal criteria in PA0008. For any subject with an ongoing SAE, 
or a history of serious infections (including hospitalizations) in the lead-in study, the Medical 
Monitor must be consulted prior to the subject’s entry into PA0009. 
6.3 
Withdrawal criteria 
Subjects are free to withdraw from the study at any time, without prejudice to their continued 
care. 
Subjects should be withdrawn from the study and will be asked to complete the Early 
Termination (ET) Visit and SFU Visit (20 weeks after the last received dose) if any of the 
following events occur: 
1. Subject withdraws his/her consent. 
2. There is confirmation of a pregnancy in a female subject during the study, as evidenced by a 
positive pregnancy test. 
3. The Sponsor or a regulatory agency requests withdrawal of the subject. 
4. Subject 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. 
5. Subject develops erythrodermic, guttate, or generalized pustular form of PSO. 
6. Subjects considered to have either a suspected new latent tuberculosis (LTB) infection or 
who develops an active tuberculosis (TB) or nontuberculosis mycobacterium infection during 
the study (including but not limited to, conversion demonstrated by interferon-gamma release 
assay (IGRA) or other diagnostic means) must be immediately discontinued from study 
medication and an unscheduled visit must be conducted as soon as possible, but not later than 
the next regular visit. 
The subject must be permanently withdrawn if further examinations result in a diagnosis of 
active TB, or if the subject is diagnosed with LTB infection 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 per protocol requirements until such time as the TB 
infection resolves.  
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7. Subject is noncompliant with the study procedures or medications that may present a risk to 
the safety of the subject in the opinion of the Investigator. 
8. Subject uses prohibited concomitant medications as defined in Section 7.8.2 that may present 
a risk to the safety of the subject in the opinion of the Investigator and/or the Medical 
Monitor. 
9. Subject develops laboratory abnormalities (with or without clinical symptoms) of alanine 
aminotransferase (ALT) or aspartate aminotransferase (AST) as defined in Section 6.3.1; 
neutrophils <0.5x109/L (neutropenia); lymphocytes <0.5x109/L (lymphopenia). Any 
laboratory value or change judged to be clinically significant by the Investigator should 
prompt consideration of whether the subject should continue on the investigational medicinal 
product (IMP). For clarification, laboratory values that are markedly abnormal as per 
Table 17-1 and Table 17‒2 will be flagged to the Investigator and to the medical monitor but 
do not trigger mandatory withdrawal unless listed above. (Refer to Section 6.3.1 for 
withdrawal criteria in relation to potential drug-induced liver injury [PDILI].) 
10. Subject has active suicidal ideation as indicated by a positive response (“Yes”) to 
Questions 4 or 5 or to the suicidal behavior questions of the “Since Last Visit” version of the 
self-rated electronic Columbia-Suicide Severity Rating Scale (eC-SSRS). The subject should 
be referred immediately to a Mental Healthcare Professional and must be withdrawn from the 
study. 
11. Subjects with a HADS-D score ≥15 must be withdrawn. Any subject who develops a 
HADS-D score of >10 during the study should be referred immediately to a Mental 
Healthcare Professional for further evaluation and potential withdrawal by the Investigator.  
12. Subjects with newly diagnosed inflammatory bowel disease (IBD) or with IBD flares during 
the study must: 
 Be referred, as appropriate, to a health care professional treating IBD, such as a 
gastroenterologist 
 Discontinue IMP and be followed-up until resolution of active IBD symptoms 
If IBD flares increase in severity or frequency during the study, the Investigator should use 
clinical judgment in deciding whether the subject should continue in the study and contact 
the Medical Monitor and UCB study physician to confirm the subject's suitability for 
continued participation in the study. 
All subjects who withdraw from the study due to an AE must be followed until resolution of the 
event or until the event is considered stable. All subjects who withdraw from the study due to 
development of a laboratory abnormality must be closely monitored. 
Investigators should attempt to obtain information on subjects in the case of withdrawal or 
discontinuation. For subjects considered lost to follow-up, the Investigator should make an effort 
(at least 1 phone call and 1 written message to the subject) 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 subject, must be recorded in the source 
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documents. The electronic Case Report Form (eCRF) must document the primary reason for 
withdrawal or discontinuation. 
Investigators should contact the Medical Monitor, whenever possible, to discuss the withdrawal 
of a subject in advance. 
6.3.1 
Potential drug-induced liver injury investigational medicinal product 
discontinuation criteria 
Subjects with 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.  
The PDILI criteria below require immediate discontinuation of IMP:   
Subjects with either of the following:  
 ALT or AST ≥5x upper limit of normal (ULN) 
 ALT or AST ≥3xULN and coexisting total bilirubin ≥2xULN  
 Subjects with ALT or AST ≥3xULN who exhibit temporally associated symptoms of 
hepatitis or hypersensitivity. Hepatitis symptoms include fatigue, nausea, vomiting, right 
upper quadrant pain or tenderness. Hypersensitivity symptoms include fever (without clear 
alternative cause), rash, or eosinophilia (ie, >5%).  
The PDILI criterion below allows for subjects to continue on IMP at the discretion of the 
Investigator.  
 Subjects with ALT or AST ≥3xULN (and ≥2x Baseline) and <5xULN, total bilirubin 
<2xULN, and no eosinophilia (ie, ≤5%), 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 9.5.1.  
If subjects are unable to comply with the applicable monitoring schedule, IMP must be 
discontinued immediately. 
Investigators should attempt to obtain information on subjects in the case of IMP discontinuation 
to complete the final evaluation. Subjects 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 subject withdrawal (if 
applicable), must be recorded in the source documents. The CRF must document the primary 
reason for IMP discontinuation. 
7 
STUDY TREATMENT 
7.1 
Description of investigational medicinal product 
Bimekizumab will be supplied by UCB Clinical Trial Supply Operations or designee. 
The IMP will consist of the following: 
 Bimekizumab will be supplied as a clear to opalescent, colorless to slightly brown, 
sterile, preservative-free solution in a 1mL prefilled syringe (PFS). 
 
 
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Further details of the IMP and specifications are provided in the Investigational Medicinal 
Product Handling Manual. 
7.2 
Treatment to be administered 
All subjects will receive bimekizumab 160mg Q4W sc (Section 5.1).  
The IMP (bimekizumab) will be administered at the visits indicated in Table 5‒1. The minimum 
time between doses should be no less than 21 days and no more than 35 days for Q4W dosing. 
The IMP is to be administered as 1 sc injection for the 160mg dose. Administration will occur at 
the study site for the first 3 months of PA0009.  
Thereafter and in between the quarterly study visits at the site, the subjects will have the option 
to perform self-administration at home. From the Entry Visit onwards, self-administration 
training will be provided to the subject/caregivers/appropriate designee by the study nurse. At 
Week 8 and Week 12, the subject/caregiver/appropriate designee will perform administration 
under the supervision of the site staff to ensure that study medication is being properly and safely 
injected.  
Once subjects/caregivers/appropriate designees as determined by the Investigator (or designee) 
have been trained, the study medication may be administered at home. The subject will receive 
the required number of injections at each visit needed to perform the monthly administrations at 
home. Subjects who are unable to or decide not to self‑administer or those without a family 
member/friend/caregiver (or appropriate designee) who can help will not be discontinued but 
may continue to visit the site for only study treatment administration. If administered at home, 
the subject/caregiver (or appropriate designee) will document the date, body location, and time 
point of administration of study medication.  
Suitable areas for sc injections are the lateral abdominal wall, upper outer thigh, and upper arm if 
the IMP is injected by a healthcare provider or a caregiver. Injection sites should be rotated and 
injections should not be given into areas where the skin is tender, bruised, red, or hard. It is also 
acceptable to inject in the upper arm if the preferred areas of the abdomen or thigh are covered in 
lesions, tender, or bruised. 
An IMP Handling Manual will be provided to each site containing instructions regarding drug 
preparation and dosing. 
7.3 
Packaging 
Bimekizumab will be packaged and labeled according to Good Manufacturing Practice (GMP) 
guidelines and applicable laws or regulations. It will be suitably packaged in such a way as to 
protect the product from deterioration during transport and storage. Further information 
regarding storage and transport conditions are provided in the IMP Handling Manual. 
7.4 
Labeling 
Clinical drug supplies will be labeled in accordance with the current International Council for 
Harmonisation (ICH) guidelines on Good Clinical Practice (GCP) and GMP and will include any 
locally required statements. If necessary, labels will be translated into the local language. 
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7.5 
Handling and storage requirements 
Investigational Medicinal Product must be stored under refrigerated conditions (2ºC to 8ºC) 
protected from light. The IMP must not be frozen.  
The investigator (or designee) is responsible for the safe and proper storage of IMP at the site. 
Investigational medicinal product stored by the investigator is to be kept in a secured area with 
limited access according to the storage conditions mentioned on the label. 
Appropriate storage conditions must be ensured either by controlling the temperature (eg, room, 
refrigeration unit) or by completion of a temperature log in accordance with local requirements 
on a regular basis (eg, once a week), showing actual and minimum/maximum temperatures 
reached over the time interval. 
In case an out-of-range temperature is noted, it must be immediately communicated to the 
Clinical Project Manager (CPM) (or designee) before further use of the IMP. 
Investigational medicinal product will be shipped to the study sites in temperature-controlled 
containers. Out-of-range shipping or storage conditions must be brought to the attention of the 
Sponsor or designee, immediately. Authorization to use any out-of-range IMP must be 
documented and received prior to dispensing or administering the IMP at the study site.  
The Investigator (or designee) will instruct the subject how to handle the IMP during the 
transport and how to store the IMP following the instruction guide. Cooler bags with freezer 
packs will be provided to the subjects. Specific attention will be put on the transport from site to 
home using cold bags; the subject will be instructed to put the IMP as quickly as possible into 
his/her refrigerator. In case of broken refrigerator or broken or lost syringes, the subject will 
inform the site immediately and new IMP will be prepared. All efforts should be made to follow 
the treatment schedule as per protocol. 
7.6 
Drug accountability 
A Drug Accountability form will be used to record IMP dispensing and return information on a 
by-subject 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. 
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 drug 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 (SOPs) or returned to UCB (or designee). Onsite destruction of used kits only may be 
allowed with prior approval from the Sponsor or designee after reconciliation. The 
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subjects/caregivers return the documentation together with any used/unused containers at the 
next scheduled clinic visit. 
Investigational medicinal product intended for the study cannot be used for any other purpose 
than that described in this protocol. 
7.7 
Procedures for monitoring subject compliance 
The IMP will be administered in the clinic during the first 3 months of treatment (Visit 1 [study 
entry] through Visit 4 [W12]) and compliance will be determined at the visit by study personnel. 
Thereafter, self-administration at home will be possible at Weeks 16, 20, 28, 32, 40, 44, 52, 56, 
64, 68, 76, 80, 88, and 92. Dates and time of self-administration will be captured using a subject 
diary. All used PFS will be disposed of by subjects/caregivers/appropriate designee as 
determined by the Investigator in an acceptable disposal (sharps) container directly after the 
administration. The subjects/caregivers return the documentation together with any used/unused 
containers at the next scheduled clinic visit. 
Drug accountability must be recorded on the Drug Accountability Form. If a subject is 
noncompliant with the study procedures or medications that may present a risk to the safety of 
the subject in the opinion of the Investigator, then the subject should be withdrawn as described 
in Section 6.3. 
7.8 
Concomitant medications/treatments 
All concomitant medications, including over the counter products, herbal, traditional remedies, 
vitamin/mineral supplements, other dietary supplements, “nutraceuticals,” and hormones must be 
recorded in the subject’s source documentation (eg, clinical chart) and on the eCRF. This record 
should include the name of the drug, the dose, the route and date(s) of administration, and the 
indication for use. 
The Investigator should examine the acceptability of all concomitant procedures, medications, 
topical preparations, and dietary supplements not explicitly prohibited in this study, and if 
necessary, discuss with the Medical Monitor. 
In order to ensure that appropriate concomitant therapy is administered, subjects will be 
instructed to consult with the Investigator prior to taking any medication (either 
self-administered nonprescription drugs or prescription therapy prescribed by another physician). 
7.8.1 
Permitted concomitant treatments (medications and therapies) 
Medication changes are permitted at any time after enrollment into this extension study. 
Medication changes and additions are permitted with the following guidelines: 
 Nonsteroidal anti-inflammatory drugs (NSAIDs), DMARDs (methotrexate, sulfasalazine, 
leflunomide, apremilast), and/or joint injections may be given if deemed appropriate by the 
Investigator as outlined below. Subjects may receive these add-on therapies while continuing 
to receive bimekizumab. Under no circumstances should subjects have a concomitant 
biologic agent while receiving bimekizumab. 
 For subjects taking NSAIDs/cyclooxygenase-2 (COX-2) inhibitors, a change can be 
made to a different NSAID/COX-2. Changes from an NSAID to a COX-2 inhibitor or 
from a COX-2 inhibitor to an NSAID are permitted up to the maximum approved or 
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tolerated dose, whichever is less. Only 1 NSAID/COX-2 inhibitor may be taken at a 
given time. 
 For subjects not taking NSAID/COX-2 inhibitors, either can be initiated, up to the 
maximum approved or tolerated dose, whichever is lower. Only 1 NSAID/COX-2 may be 
taken at a given time. 
 Methotrexate may be added or increased to a maximum dose of 25mg/week, or the 
maximum tolerated dose, whichever is lower. The route of administration may be 
changed from oral to sc or from sc to oral. It is strongly recommended that subjects 
taking MTX should also take folic acid supplementation. 
 Sulfasalazine may be given up to a maximum dose of 3g/day, or the maximum tolerated 
dose, whichever is lower, for peripheral arthritis symptoms.  
 Leflunomide may be given at a maximum dose of 20mg/day (or an average of 20mg/day 
if not dosed daily), or the maximum tolerated dose, whichever is lower, for peripheral 
arthritis symptoms. Leflunomide should not be used concomitantly with MTX. 
 Apremilast may be given at a maximum dose of 30mg twice daily, or the maximum 
tolerated dose, whichever is lower. 
 Combination DMARDs (optimally 2) are allowed except that leflunomide and MTX may 
not be given together. 
 No other oral DMARDs are permitted during this OLE study. 
 Steroid tapers for disease activity or disease-related reasons are allowed with an average 
daily dose of 20mg prednisone or prednisone equivalent per day for a maximum of 14 days.  
 Up to 1 injection per joint for up to 3 discrete joints is permitted per 12-month period. 
Investigators should follow the guidance in the CRF instructions for proper scoring of the 
injected joints. 
 Intra-articular hyaluronic acid injections are permitted into joints for which they are approved 
as per local labels.  
 Intra-bursal corticosteroid injections are also permitted at the discretion of the Investigator. 
 A decrease in dose or dosing frequency of any agent is permitted at any time. 
 Subjects with persistent active disease in spite of added concomitant therapy/therapies 
mentioned above should be withdrawn from the study at the discretion of the Investigator. 
Psoriasis treatments 
For treatment of PSO, subjects may continue to use topical moisturizers, emollients, salicylic 
acid preparations, bath oils, and oatmeal bath preparations for skin conditions during the study, 
as needed. Over-the-counter shampoos for the treatment of PSO of the scalp are also permitted. 
Mild topical steroids are permitted for use limited to the face, axillae, and/or genitalia, as needed. 
More potent topical steroids, topical retinoids, vitamin D analogues, and/or coal tar preparations 
may be used as medically required to treat a flare. Use of psoralen and ultraviolet A light 
(PUVA/UVA) therapy for the treatment of PSO is discouraged through the duration of the study. 
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7.8.2 
Prohibited concomitant treatments (medications and therapies) 
Prohibited and/or restricted medications are summarized in Table 7-1 and Table 7-2. 
Table 7-1: 
Prohibited or restricted medications 
Drug class 
Dose 
Comments 
Analgesics, including opioid 
analgesics 
(acetaminophen/paracetamol, etc) 
Any dose  
Any ad hoc use in the 24 hours prior to 
any study visit is prohibited.  
 
Stable doses of analgesics (including 
opioids) permitted. 
TNF inhibitor: 
-infliximab  
-adalimumab  
-etanercept  
-golimumab  
-certolizumab pegol  
Any dose 
This applies to biosimilar versions of any 
TNF inhibitors. 
Any non-TNF biologic medications 
Any dose 
Any exposure history is prohibited. 
All other DMARDs 
Any dose 
Only permitted medications as per 
Section 7.8.1. 
DMARD=disease-modifying antirheumatic drug; TNF=tumor necrosis factor 
 
Table 7-2: 
Additional prohibited psoriasis treatments 
Drug class 
Phototherapy 
High potency topical steroid, vitamin D analogues, topical retinoids, keratolytics, coal tar, fumaric acid 
esters use except as detailed in Section 7.8.1 
Systemic retinoids 
Subjects who take prohibited medications may be withdrawn from study treatment but followed 
until the SFU Visit. The decision to withdraw a subject for taking prohibited medications should 
be made in consultation with the Medical Monitor. 
Vaccines 
Administration of live, attenuated vaccines is not allowed during the conduct of the study or for 
20 weeks after the last dose of study drug. Administration of non-live, inactivated vaccines is 
allowed during the study at the discretion of the Investigator. 
Live vaccinations include, but are not limited to, the following: anthrax vaccine, intranasal 
influenza vaccine, measles-mumps-rubella vaccine, polio live oral vaccine, smallpox vaccine, 
TB Bacillus Calmette-Guérin vaccine, typhoid live oral vaccine, varicella vaccine, and yellow 
fever vaccine. 
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7.9 
Blinding 
This is an open label study. All subjects’ treatment assignments during the lead-in studies will 
remain blinded until final database lock of PA0008. 
7.10 
Randomization and numbering of subjects 
This is an OLE study and no randomization will be performed. All subjects will receive 
bimekizumab 160mg Q4W sc. 
Subjects will continue with the 5-digit subject numbers assigned by the interactive web or voice 
response system (IXRS) in the preceding study.  
8 
STUDY PROCEDURES BY VISIT  
The schedule of study assessments (Table 5‒1) provides a general overview of study 
assessments. A list of procedures to be completed at each visit is provided in the sections that 
follow.  
 
Visit windows of ±7 days on either side of the scheduled dosing are permitted for all visits 
other than the SFU Visit (see below); however, the Investigator should try to keep the 
subjects on the original dosing schedule. The window of ±7 days is relative to the first dose 
(PA0009 entry) and applicable for all subsequent visits. Changes to the dosing schedule 
outside of the 14-day window must be discussed with the Medical Monitor. 
 
The minimum time between doses should be no less than 21 days and no more than 35 days 
for Q4W dosing. 
 
For the SFU Visit (20 weeks after the last dose), the visit should occur no more than 3 days 
prior to the scheduled visit date and within 7 days after the scheduled visit date 
(-3 days/+7 days). 
The Investigator should make efforts to maintain the original visit schedule. Changes to the 
dosing schedule outside of the allowed windows must be discussed with the Medical Monitor 
and may result in subject withdrawal.  
8.1 
Visit 1 
The PA0009 entry assessments noted with an “*” will be obtained at the Week 48 Visit of 
PA0008 and do not need to be recorded on the eCRF for this study.  
The following procedures or assessments will be completed prior to administration of IMP: 
 Ensure that a separate ICF is completed by the subject for PA0009 (must be done prior to any 
PA0009 study procedures) 
 Assessment of inclusion/exclusion criteria 
 Record concomitant medications* 
 Record AEs* 
 eC-SSRS* 
 HADS* 
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 Administer the Health Assessment Questionnaire—Disability Index (HAQ-DI)* 
 Administer the SF-36* 
 Administer the Patient’s Global Assessment of Disease Activity (PGADA)* 
 Administer the Patient’s Assessment of Arthritis Pain (PtAAP)* 
 Administer the PsAID-9* 
 Administer the TB questionnaire* 
 Measure vital signs (temperature, pulse, and blood pressure [BP])* 
 Measure body weight* 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB* 
 Perform tender joint count (TJC)/swollen joint count (SJC)* 
 Determine BSA affected by PSO using the BSA palm method* 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the Psoriasis Area and 
Severity Index (PASI)* 
 Determine the MASES* 
 Determine the LDI* 
 Perform the Physician’s Global Assessment of Disease Activity (PhGADA)* 
 Perform an electrocardiogram (ECG)* 
 Collect samples for hematology/biochemistry/urine pregnancy* 
 Collect blood sample for CRP* 
 Collect blood sample for bimekizumab plasma concentrations and anti-bimekizumab 
antibody detection* 
 Perform an IGRA TB test if applicable 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP at 30 minutes and 1 hour after dosing 
 
8.2 
Week 4 (Visit 2) and Week 8 (Visit 3) 
The following procedures or assessments will be completed prior to administration of IMP: 
 Record concomitant medications 
 Record AEs 
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 eC-SSRS 
 Measure vital signs (temperature, pulse, and BP) 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP once after dosing at any time 
 
8.3 
Week 12 (Visit 4), Week 24 (Visit 5), Week 36 (Visit 6), and 
Week 72 (Visit 9) 
The following procedures or assessments will be completed prior to administration of IMP: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS 
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire 
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 Determine the MASES 
 Determine the LDI 
 Perform the PhGADA 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
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 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP once after dosing at any time  
 
8.4 
Week 16, Week 20, Week 28, Week 32, Week 40, Week 44, 
Week 52, Week 56, Week 64, Week 68, Week 76, Week 80, 
Week 88, and Week 92 
Subjects will be given the opportunity for self-administration of bimekizumab. Adverse events 
will be captured spontaneously if the subject decides to visit the site to receive the bimekizumab 
administration. 
 
8.5 
Week 48 (Visit 7) and Week 96 (Visit 11) 
The following procedures or assessments will be completed prior to administration of IMP: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS  
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
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 Determine the MASES 
 Determine the LDI 
 Perform the PhGADA 
 Perform an ECG 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Perform an IGRA TB test 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP once after dosing at any time 
 
8.6 
Week 60 (Visit 8) and Week 84 (Visit 10) 
The following procedures or assessments will be completed prior to administration of IMP: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS  
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
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 Determine the LDI 
 Perform the PhGADA 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP once after dosing at any time 
 
8.7 
Week 100 (Visit 12) 
The following procedures or assessments will be completed prior to administration of IMP: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS  
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 Determine the LDI 
 Perform the PhGADA 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
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 Collect blood sample for CRP 
 Record visit in the IXRS 
 Bimekizumab will be administered after all of the above assessments have been completed 
The following procedures or assessments will be completed following administration of IMP: 
 Collect pulse and BP once after dosing at any time 
 
8.8 
Week 104 (Visit 13) or Early Termination Visit 
The following procedures or assessments will be completed: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS  
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 Determine the MASES 
 Determine the LDI 
 Perform the PhGADA 
 Perform an ECG 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
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 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Record visit in the IXRS 
 
8.9 
SFU Visit (20 weeks after the final dose of IMP) 
The following procedures or assessments will be completed: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Perform an IGRA TB test 
 Record visit in the IXRS 
8.10 
Early Termination Visit 
Subjects withdrawing early from the study (see Section 6.3) will undergo the same assessments 
as the Week 104 Visit (see Section 8.8) and will enter the SFU Period. 
8.11 
Unscheduled Visit 
At the Investigator’s discretion, an Unscheduled Visit may be completed at any time during the 
study but prior to the SFU Visit, if deemed necessary for the subject’s safety and well-being. 
If an Unscheduled Visit is conducted due to safety or efficacy reasons, an eC-SSRS assessment 
will be performed with the subject during the visit. If an Unscheduled Visit is conducted for 
reasons other than safety or efficacy concerns (eg, replacement of lost medication, repeated 
collection of a laboratory specimen due to collection or analysis issues) an eC-SSRS will not be 
required at these visits. 
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At this visit, any of the following assessments may be performed, depending on the reason for 
the visit: 
 
Record concomitant medication 
 
Record AEs 
 
eC-SSRS 
 
Measure vital signs (temperature, pulse, and BP) 
 
Physical examination 
 
Record 12-lead ECG  
 
If medically indicated, obtain blood sample(s) for standard safety laboratory tests 
(hematology, serum chemistry)  
 
Obtain urine sample for standard safety laboratory tests (including urine pregnancy test in 
women of childbearing potential). 
9 
ASSESSMENT OF SAFETY 
9.1 
Adverse events 
9.1.1 
Definition of AE 
An AE is any untoward medical occurrence in a patient or clinical investigation subject 
administered a pharmaceutical product that does not necessarily have a causal relationship with 
this treatment. An AE can therefore be any unfavorable and unintended sign (including an 
abnormal laboratory finding), symptom, or disease temporally associated with the use of a 
medicinal (investigational) product, whether or not related to the medicinal (investigational) 
product. 
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 initial visit and all AEs that 
recurred or worsened after the initial visit. 
Signs or symptoms of the condition/disease for which the IMP is being studied should be 
recorded as AEs only if their nature changes considerably or their frequency or intensity 
increases in a clinically significant manner as compared to the clinical profile known to the 
investigator from the subject’s history or study entry. 
Adverse events that occurred during the PA0008 lead-in study and are still deemed ongoing at 
the time of enrolment (signed ICF) will be captured in the database and followed up, as 
described in Section 9.1.6. 
9.1.2 
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 
administration of a UCB product/compound. 
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Potential Hy’s Law, defined as ≥3xULN ALT or AST with coexisting ≥2xULN total bilirubin in 
the absence of ≥2xULN alkaline phosphatase (ALP), with no alternative explanation for the 
biochemical abnormality, must ALWAYS be reported to UCB as an AESI (ie, without waiting 
for any additional etiologic investigations to have been concluded). Follow-up information 
should then be reported if an alternative etiology is identified during investigation and 
monitoring of the subject.  
9.1.3 
Other safety topics of interest 
Pre-specified safety topics of interest for the study are: infections (serious, opportunistic, fungal 
and TB), neutropenia, hypersensitivity, suicidal ideation and behavior, depression, major 
cardiovascular events, liver function test changes/enzyme elevations, malignancies, and 
inflammatory bowel diseases (with gastroenterology referral, as appropriate). This is based on 
findings from the IMP 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. 
9.1.4 
Procedures for reporting and recording AEs 
The subject will be given the opportunity to report AEs spontaneously. A general prompt will 
also be given at each study visit to detect AEs. For example: 
“Did you notice anything unusual about your health (since your last visit)?” 
In addition, the Investigator should review any self-assessment procedures (eg, diary cards) 
employed in the study. 
9.1.5 
Description of AEs 
When recording an AE, the Investigator should use the overall diagnosis or syndrome using 
standard medical terminology, rather than recording individual symptoms or signs. The eCRF 
and source documents should be consistent. Any discrepancies between the subject’s own words 
on his/her own records (eg, diary card) and the corresponding medical terminology should be 
clarified in the source documentation. 
When recording the intensity of an AE in the CRF (ie, mild, moderate, or severe), the 
Investigator should use the following criteria: 
 Mild: the subject is aware of the sign or symptom (syndrome), but it does not interfere with 
his/her usual activities and/or is of no clinical consequence 
 Moderate: the AE interferes with the usual activities of the subject or it is of some clinical 
consequence 
 Severe: the subject is unable to work normally or to carry out his/her usual activities, or the 
AE is of definite clinical consequence 
Details for completion of the AE eCRF (including judgment of intensity and relationship to IMP) 
are described in the eCRF Completion Guidelines. 
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9.1.6 
Follow-up of AEs 
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 subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and other safety topics of interest; further 
details regarding follow-up of PDILI events are provided in Section 9.5.1.5. Information on 
SAEs obtained after clinical database lock will be captured through the Patient Safety (PS) 
database without limitation of time. 
If an AE is ongoing at the end of the study for a subject, follow-up should be provided until 
resolution/stable level of sequelae is achieved, or until the Investigator no longer deems that it is 
clinically significant, or until the subject is lost to follow-up. If no follow-up is provided, the 
Investigator must provide a justification. The follow-up will usually be continued for 20 weeks 
after the subject has discontinued his/her IMP. 
9.1.7 
Rule for repetition of an AE 
An increase in the intensity of an AE should lead to the repetition of the AE being reported with: 
 The outcome date of the first AE that is not related to the natural course of the disease being 
the same as the start date of the repeated AE, and the outcome of “worsening” 
 The AE verbatim term being the same for the first and repeated AE, so that the repeated AE 
can be easily identified as the worsening of the first one 
9.1.8 
Pregnancy 
If an Investigator is notified that a subject has become pregnant after the first intake of any IMP, 
the Investigator must immediately notify UCB’s PS department by providing the completed 
Pregnancy Report and Outcome Form (for contact details see SAE reporting information at the 
beginning of this protocol). The subject should be withdrawn from the study as soon as 
pregnancy is known (by positive pregnancy test), and the following should be completed: 
 The subject should return for the ET Visit. 
 The subject should immediately stop the intake of the IMP. 
 An SFU Visit should be scheduled 20 weeks after the subject has discontinued her IMP. 
The Investigator must inform the subject of information currently known about potential risks 
and about available treatment alternatives. 
The pregnancy will be documented on the Pregnancy Report and Outcome Form provided to the 
Investigator. The progression of the pregnancy and the eventual birth (if applicable) must be 
followed up using the Pregnancy Report and Outcome Form in which the Investigator has to 
report on the health of the mother and of the child. Every reasonable attempt should be made to 
follow the health of the child for 30 days after birth for any significant medical issues. In certain 
circumstances, UCB may request that follow-up is continued for a period longer than 30 days. If 
the subject is lost to follow-up and/or refuses to give information, written documentation of 
attempts to contact the subject needs to be provided by the Investigator and filed at the site. 
UCB’s PS department is the primary contact for any questions related to the data collection for 
the pregnancy, eventual birth, and follow-up. 
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In cases where the partner of a male subject enrolled in a clinical study becomes pregnant, the 
Investigator or designee is asked to contact the subject 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/Contract Research Organization (CRO) contract monitor for 
the study. The Investigator will complete the Pregnancy Report and Outcome Form and send it to 
UCB’s PS department (for contact details see SAE reporting information at the beginning of this 
protocol) 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. 
A pregnancy becomes an SAE in the following circumstances: miscarriage, elective abortion 
when medically indicated (e.g. when pregnancy is endangering life or health of woman or when 
fetus will be born with severe abnormalities), unintended pregnancy after hormonal 
contraceptive failure (if the hormonal contraceptive was correctly used), ectopic pregnancy, fetal 
demise, or any congenital anomaly/birth defect of the baby. Those SAEs must be additionally 
reported using the Investigator SAE Report form. 
9.1.9 
Suspected transmission of an infectious agent via a medicinal 
product 
For the purposes of reporting, any suspected transmission of an infectious agent via a medicinal 
product should be considered as an SAE; such cases must be reported immediately, recorded in 
the AE module of the eCRF, and followed as any other SAE. Any organism, virus, or infectious 
particle (eg, prion protein transmitting transmissible spongiform encephalopathy), pathogenic or 
nonpathogenic, is considered an infectious agent. 
9.1.10 
Overdose of investigational medicinal product 
Excessive dosing (beyond that prescribed in the protocol and including overdose) should be 
recorded in the eCRF. Any SAE or nonserious AE associated with excessive dosing must be 
followed as any other SAE or nonserious AE. These events are only considered AEs or SAEs if 
there are associated clinical signs and symptoms or if the act of taking the excess medicine itself 
is an AE or SAE (eg, suicide attempt). 
9.1.11 
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, clinical study subjects, regulatory 
authorities, and IRBs/IECs will be informed appropriately and as early as possible. 
The Study Physician or medically qualified designee/equivalent will conduct an ongoing review 
of SAEs and perform ongoing SAE reconciliations in collaboration with the 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 or ECG results) for which data will be periodically reviewed during the course 
of the study. 
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In addition, Cardiovascular and Neuropsychiatric Adjudication Committees will also periodically 
review and monitor the safety data from this study and advise UCB. Details are provided in the 
Adjudication Committee Charters. 
9.2 
Serious AEs 
9.2.1 
Definition of SAEs 
Once it is determined that a subject experienced an AE, the seriousness of the AE must be 
determined. An SAE must meet 1 or more of the following criteria: 
 Death 
 Life-threatening 
 (Life-threatening does not include a reaction that might have caused death had it occurred in 
a more severe form.) 
 Significant or persistent disability/incapacity 
 Congenital anomaly/birth defect (including that occurring in a fetus) 
 Important medical event that, based upon appropriate medical judgment, may jeopardize the 
patient or subject and may require medical or surgical intervention to prevent 1 of the other 
outcomes listed in the definition of serious. 
(Important medical events may include, but are not limited to, potential Hy’s Law [see 
Section 9.1.2], allergic bronchospasm requiring intensive treatment in an emergency room or 
at home, blood dyscrasias that do not result in inpatient hospitalization, or the development 
of drug dependency or drug abuse.) 
 Initial inpatient hospitalization or prolongation of hospitalization 
A patient admitted to a hospital, even if he/she is released on the same day, meets the criteria 
for the initial inpatient hospitalization. An emergency room visit that results in admission to 
the hospital would also qualify for the initial inpatient hospitalization criteria. However, 
emergency room visits that do not result in admission to the hospital would not qualify for 
this criteria and, instead, should be evaluated for 1 of the other criteria in the definition of 
serious (eg, life-threatening adverse experience, important medical event). 
Hospitalizations for reasons not associated with the occurrence of an AE (eg, preplanned 
surgery or elective surgery for a pre-existing condition that has not worsened or manifested 
in an unusual or uncharacteristic manner) do not qualify for reporting. For example, if a 
subject has a condition recorded on his/her medical history and later has a preplanned surgery 
for this condition, it is not appropriate to record the surgery or hospitalization as an SAE, 
since there is no AE upon which to assess the serious criteria. Please note that, if the 
pre-existing condition has worsened or manifested in an unusual or uncharacteristic manner, 
this would then qualify as an AE and, if necessary, the seriousness of the event would need to 
be determined. 
Note: Confirmed active TB is always to be considered as an SAE and must be captured on an 
SAE Report Form and provided to the Sponsor in accordance with SAE reporting requirements. 
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9.2.2 
Procedures for reporting serious adverse events 
If an SAE is reported, UCB must be informed within 24 hours of receipt of this information by 
the site (see contact information for SAE reporting listed in the SAE Reporting section at the 
front of the protocol). The Investigator must forward to UCB (or its representative) a duly 
completed “Investigator SAE Report Form for Development Drug” (SAE report Form) provided 
by UCB, even if the data are incomplete, or if it is obvious that more data will be needed in order 
to draw any conclusions. Information recorded on this form will be entered into the global PS 
database. 
An Investigator SAE report Form will be provided to the Investigator. The Investigator SAE 
Report Form must be completed in English. 
It is important for the Investigator, when completing the SAE report Form, to include the 
assessment as to a causal relationship between the SAE and the IMP administration. This insight 
from the Investigator is very important for UCB to consider in assessing the safety of the IMP 
and in determining whether the SAE requires reporting to the regulatory authorities in an 
expedited manner. 
Additional information (eg, autopsy or laboratory reports) received by the Investigator must be 
provided within 24 hours. All documents in the local language must be accompanied by a 
translation in English, or the relevant information included in the same document must be 
summarized in the Investigator SAE report Form. 
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 
30 days from the end of the study for each subject, and to also inform participating subjects 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. 
Upon receipt of the SAE report Form, UCB will perform an assessment of expectedness of the 
reported SAE. The assessment of the expectedness of the SAE is based on the IB. 
9.2.3 
Follow-up of SAEs 
An SAE should be followed until it has resolved, has a stable sequelae, the Investigator 
determines that it is no longer clinically significant, or the subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and other safety topics of interest; further 
details regarding follow-up of PDILI events are provided in Section 9.5.1.5. Information on 
SAEs obtained after clinical database lock will be captured through the PS database without 
limitation of time. 
9.3 
Immediate reporting of AEs 
The following AEs must be reported immediately: 
 SAE: AE that the Investigator classifies as serious by the above definitions regardless of 
causality 
 Suspected transmission of an infectious agent via a medicinal product 
 AEs of special interest as defined in Section 9.1.2  
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9.4 
Anticipated SAEs 
The following list of Anticipated SAEs (Table 9‒1) has been identified, as these events are 
anticipated to occur in the population studied in this protocol at some frequency that is 
independent of drug exposure. This original list will remain in effect for the duration of the 
protocol. Note that listed events will not be regarded as anticipated SAEs if they are life 
threatening or if they result in the death of the study subject. 
This list does not change the Investigator’s obligation to report all SAEs (including Anticipated 
SAEs) as detailed in Section 9.2.2. 
Table 9‒1: 
Anticipated SAEs for the population of subjects with psoriatic 
arthritis 
MedDRA system organ class 
MedDRA preferred term 
Eye disorders 
Uveitis 
Cardiac disorders 
Myocardial infarction 
Atrial fibrillation 
Gastrointestinal disorders 
Crohn's disease 
Hepatobiliary disorders 
Non-alcoholic steatohepatitis 
Metabolism and Nutrition disorders 
Metabolic syndrome 
Diabetes mellitus 
Musculoskeletal and connective tissue disorders 
Psoriatic arthropathy 
Neoplasms benign, malignant and unspecified 
(incl cysts and polyps) 
Basal cell carcinoma 
Squamous cell carcinoma 
Nervous system disorders 
Embolic Stroke 
Ischaemic Stroke 
Psychiatric disorders 
Anxiety 
Depression 
Skin and subcutaneous tissue disorders 
Psoriasis 
MedDRA=Medical Dictionary for Regulatory Activities 
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 subject.  
9.5 
Laboratory measurements 
Clinical laboratory assessments consist of serum chemistry, and hematology (Table 9-2). A 
centralized laboratory will be used to supply all laboratory test supplies and analyze all blood 
samples for hematology, and biochemistry measurements. Any unscheduled laboratory testing 
should also be collected using the central laboratory. 
Specific details regarding the handling and processing of serum chemistry, hematology, and 
urinalysis samples are provided in the study laboratory manuals. 
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Table 9-2: 
Laboratory measurements 
Hematology 
Chemistry 
Urinalysis 
Basophils 
Calcium 
Urine dipstick for pregnancy testing a 
Eosinophils 
Chloride 
Urinalysisb 
Lymphocytes 
Magnesium 
 
Atypical lymphocytes 
Potassium 
 
Monocytes 
Sodium 
 
Neutrophils 
Glucose (random) 
 
Hematocrit 
BUN 
 
Hemoglobin 
Creatinine 
 
MCH 
AST 
 
MCHC 
ALT 
 
MCV 
ALP 
 
Platelet count 
GGT 
 
RBC count  
Total bilirubin 
 
WBC count  
LDH 
 
 
Total cholesterol 
 
 
Uric acid 
 
 
CRP  
 
ALP=alkaline phosphatase; ALT=alanine aminotransferase; AST=aspartate aminotransferase; BUN=blood urea 
nitrogen; CRP=C-reactive protein; GGT=gamma glutamyltransferase; LDH=lactate dehydrogenase; 
MCH=mean corpuscular hemoglobin; MCHC=mean corpuscular hemoglobin concentration; MCV=mean 
corpuscular volume  
a A urine pregnancy test will be performed for women of childbearing potential if there is a suspicion of 
pregnancy or a delay in menses. A positive urine pregnancy test should always be confirmed with a serum 
pregnancy test. 
b These measurements will be performed only if a urinalysis is required for safety reasons. 
9.5.1 
Evaluation of PDILI 
The PDILI IMP discontinuation criteria for this study are provided in Section 6.3.1, 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 learning 
of their occurrence. Any PDILI event that meets the criterion for potential Hy’s Law must be 
reported as an AE of special interest (see Section 9.1.2), and, if applicable, also reported as an 
SAE (see Section 9.2.2).  
Evaluation of PDILI consists of the diagnostic testing and continued monitoring included in 
Table 9-3 (specific tests dependent on laboratory results and corresponding symptoms) and 
consultation with a local hepatologist (if applicable; discussed in Section 9.5.1.1). The local 
hepatologist is the expert usually consulted by the treating physician for assessment and 
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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 9.5.1.5).  
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. 
Rechallenge with a substance potentially causing drug-induced liver injury is dangerous, may be 
fatal, and must not occur. 
Table 9-3 summarizes the approach to investigate PDILI. 
 
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Table 9-3: 
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 
≥3xULN 
≥2xULNb 
NA 
 
 
Hepatology consult.c 
Medical Monitor must be 
notified within 24 hours 
(eg, by laboratory alert) 
and subject discussed with 
Medical Monitor ASAP. 
Immediate IMP 
discontinuation. 
 
Essential: Must have 
repeat liver chemistry 
values and additional 
testing completed 
ASAP (see 
Section 9.5.1.4); 
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.d 
 
 
 
 
 
 
 
 
 
≥3xULN 
NA 
Yes 
≥5xULN 
NA 
NA 
Need for hepatology 
consult to be discussed.     
(required if ALT or AST 
≥8xULN) Medical 
Monitor must be notified 
within 24hours (eg, by 
laboratory alert) and 
subject discussed with 
Medical Monitor ASAP. 
Immediate IMP 
discontinuation 
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Table 9-3: 
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 
≥3xULN 
(and ≥2x 
baseline) and 
<5xULN 
(and ≥2x 
baseline) 
<2xULN 
No 
Discussion with Medical 
Monitor required. 
Consider need for 
hepatology consult if there 
is no evidence of 
resolution (see Follow-up 
requirements) c 
Further investigation – 
immediate IMP 
discontinuation not 
required (see 
Section 9.5.1.2). 
IMP discontinuation 
required if any of the 
following occur: 
 Subject cannot comply 
with monitoring 
schedule.  
 
Liver chemistry 
values continue to 
increase  
 
Liver chemistry 
values remain 
≥3xULN (and 
≥2xbaseline) after 2 
weeks of monitoring 
without evidence of 
resolution  
Essential: Every 
attempt must be 
made to have repeat 
liver chemistry 
values and additional 
testing completed 
within 48hours at the 
site with HCP (see 
Section 9.5.1.4). 
Monitoring of liver chemistry values at 
least twice per week for 2 weeks.d 
 
Immediate IMP discontinuation 
required if liver chemistry values 
continue to increase.  
After 2 weeks of monitoring liver 
chemistry values:  
 
Discontinue IMP if levels remain 
≥3xULN (and ≥2x baseline) 
without evidence of resolutiond  
Continue to monitor until values 
normalize, stabilize, or return to within 
Baseline valuesd. 
 
ALP=alkaline phosphatase; ALT=alanine aminotransferase; ASAP=as soon as possible; AST=aspartate aminotransferase; HCP=healthcare practitioner; 
IMP=investigational medicinal product; NA=not applicable; PDILI=potential drug induced liver injury; ULN=upper limit of normal  
a Hepatitis symptoms include fatigue, nausea, vomiting, and right upper quadrant pain or tenderness; hypersensitivity symptoms include eosinophilia (>5%), 
rash, and fever (without clear alternative cause). 
b If the subject also has ≥2xULN ALP, the possibility of an indication of biliary obstruction should be discussed with the Medical Monitor. 
c Details provided in Section 9.5.1.1. 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 Unless an alternative monitoring schedule is agreed by the investigator and UCB responsible physician. Determination of stabilization is at the discretion of the 
investigator in consultation with the hepatologist (as applicable) and UCB responsible physician, as needed. 
 
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9.5.1.1 
Consultation with Medical Monitor and local hepatologist 
Potential drug-induced liver injury events require notification of the Medical Monitor within 
24 hours (eg, by laboratory alert), and the subject must be discussed with the Medical Monitor as 
soon as possible. If required, the subject 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 9.5.1.4) and SAE report (if applicable). 
9.5.1.2 
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 discontinuation (see Section 6.3.1 and Table 9-3 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. 
9.5.1.3 
IMP restart/rechallenge 
Rechallenge with a substance potentially causing drug-induced liver injury is dangerous, may be 
fatal, and must not occur. 
9.5.1.4 
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 included, but not 
limited to those listed in Table 9‒4 (laboratory measurements) and Table 9‒5 (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 subject 
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. 
The measurements to be assessed are detailed in Table 9‒4. 
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Table 9‒4: 
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 heterophil 
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 
Toxicology screen a 
Chemistry 
Amylase 
ALT, AST 
If total bilirubin ≥1.5xULN, obtain fractionated bilirubin to obtain % direct bilirubin 
Serum CPK and LDH to evaluate possible muscle injury causing transaminase elevation 
Additional 
Prothrombin time/INR b 
Serum pregnancy test 
PK sample 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; CPK=creatine phosphokinase; HBcAb-
IgM=hepatitis B core antibody-IgM; HBsAg=hepatitis B surface antigen; IgM=immunoglobulin M; 
INR=international normalized ratio; LDH=lactate dehydrogenase; PDILI=potential drug-induced liver injury; 
PK=pharmacokinetic; RNA=ribonucleic acid; ULN=upper limit of normal 
a For detecting substances (ie, amphetamines, benzodiazepines, opioids, marijuana, cocaine, phencyclidine, and 
tricyclic antidepressants), additional tests may be performed based on the Investigator’s medical judgment and 
patient’s history. 
b Measured only for subjects with ALT >8xULN, 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 (>5%), rash, and fever (without clear alternative 
cause). 
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The following additional PDILI information is to be collected (Table 9‒5): 
Table 9‒5: 
PDILI information to be collected 
New or updated information 
Concomitant prescription 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 
9.5.1.5 
Follow-up evaluation 
Potential drug-induced liver injury events require follow-up monitoring as described in 
Table 9-3. 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 UCB responsible physician, as needed. 
9.6 
Other safety measurements 
9.6.1 
Vital signs 
The Investigator or designee should measure all vital signs (systolic and diastolic BP, 
temperature [oral, axillary, or otic], pulse rate) after the subject has been sitting for at least 
5 minutes, and the subject should remain seated during the measurements. Body temperature 
should be obtained prior to dosing with IMP at study visits when IMP is administered. At 
PA0009 study entry, collect pulse and BP prior to drug administration and then at 30 minutes 
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and 1 hour after dosing. At all other visits collect pulse and BP prior to drug administration and 
once after dosing (any time). 
9.6.2 
Body weight 
The Investigator or designee will measure the weight of the subject in kilograms at the time 
points listed in Table 5‒1. The same scale should be utilized throughout the study where 
possible. 
9.6.3 
Physical examination 
The physical examination should be conducted by the Investigator or designee at the time points 
listed in Table 5‒1 and will include general appearance; ear, nose, and throat; eyes, hair, and 
skin; respiratory; cardiovascular; gastrointestinal; musculoskeletal; hepatic; neurological 
(including limb reflexes); and mental status. Findings considered clinically significant changes 
since the physical examination at the Baseline of PA0008 will be recorded as AEs. 
9.6.4 
12-lead ECG 
The Investigator or designee will perform the ECG at the time points listed in Table 5‒1. The 
ECGs will be read locally.  
9.6.5 
Tuberculosis and TB risk factor assessment and management 
All subjects will be assessed for TB at prior to administration of IMP in PA0009 and at the time 
points specified in the schedule of study assessments (Table 5‒1) through physical examination 
for signs and symptoms of TB, laboratory testing (Section 9.6.5.1), and subject questionnaire 
(Section 9.6.5.2). 
Prior to administration of IMP, subjects will have an IGRA test (QuantiFERON TB Test is 
recommended) and examination for signs and symptoms of TB unless an IGRA negative result is 
available less than 6 weeks prior to the first dose of open-label bimekizumab. In addition, each 
subject will complete a TB questionnaire with questions directed at symptoms of TB and 
potential exposure to TB.  
Test Conversion 
Tuberculosis test conversion is defined as a positive IGRA result for the current test, when 
previous IGRA test results were negative. All subjects with TB test conversion must immediately 
stop IMP administration. In case of a TB test conversion, the subject 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. If 
test conversion indicates LTB infection, active TB, or nontuberculous mycobacteria (NTMB) 
then, per UCB TB working instructions, TB test conversion (confirmed) should be classified 
adequately, either as due to LTB infection, active TB infection, or NTMB, respectively. 
Additional assessments (eg, blood tests or IGRA, chest x-rays, or other imaging) should be 
performed where medically relevant and documented. Such conversions should be reported to 
the UCB PS function. 
Latent TB 
In case the evaluation by the appropriate specialist indicates a new LTB infection during the 
study, a prophylactic TB treatment should be initiated, and the IMP can be continued no sooner 
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than 4 weeks after start of prophylactic TB treatment, if it is deemed likely by the Investigator 
that prophylactic TB treatment is continued to completion. 
If prophylaxis is not initiated, the subject must be withdrawn. 
Every related action should be discussed in advance with the Medical Monitor.  
Once withdrawn from study treatment, subjects should return for the ET Visit, complete all 
ET Visit assessments, and complete a SFU Visit (20 weeks after the last dose of IMP). 
Active TB or NTMB infection  
Subjects who develop active TB or NTMB infection during the study must be withdrawn from 
the study. The subject must be immediately discontinued from IMP and an ET Visit must be 
scheduled as soon as possible, but no later than the next scheduled visit. The subject should be 
encouraged to keep the SFU Visit as specified by the protocol. Treatment should be started 
immediately. 
Note that subjects with history of NTMB or active NTMB infection are excluded from the study 
regardless of prior or current therapy for this condition.  
9.6.5.1 
Tuberculosis assessment by IGRA 
During conduct of the study, the TB assessment by IGRA (QuantiFERON TB Test is 
recommended) will be performed at study entry (unless an IGRA negative result is available less 
than 4 weeks prior to the first dose of open-label bimekizumab) and should be repeated at 
Week 48, Week 96, and SFU Visits for all subjects. The test results will be reported as positive, 
negative, or indeterminate. UCB also recommends that a TB specialist be consulted where TB 
(latent or active) is suspected or if there are doubts regarding test results. If latent or active TB is 
identified, subject must undergo appropriate study-specified withdrawal procedures.  
9.6.5.2 
Tuberculosis questionnaire  
The questionnaire “Evaluation of signs and symptoms of tuberculosis” should be used as a 
source document. The questionnaire will be completed at PA0009 entry, every 12 weeks 
throughout the study, at Week 104, and at the SFU Visit (Table 5‒1). The questionnaire will 
assist with the identification of subjects who may require therapy for TB. A “Yes” response to 
any of the questions during the study should trigger further assessments to determine if the 
subject has either LTB or active TB infection. 
Subjects with a confirmed latent TB (where no prophylactic treatment is initiated) or active TB 
infection must be withdrawn from the study (as further detailed in Section 9.6.5). 
9.6.5.3 
Tuberculosis management 
LTB infection and active TB identified during study 
During the study, subjects who develop evidence of LTB infection or active TB must 
immediately stop further administration of IMP and will be referred to an appropriate TB 
specialist (pulmonologist or infectious disease specialist) for further evaluation. Evidence of 
LTB infection is defined as subject’s IGRA test converts to positive or indeterminate (and 
confirmed indeterminate on repeat), or the subject’s questionnaire or history and physical 
indicates that TB infection or exposure may have occurred. Evidence of active TB includes, in 
addition to the aforementioned tests, signs, and symptoms of organ involvement. In either 
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situation, the subject should be carefully assessed by a TB specialist for active TB. Subjects 
diagnosed with active TB or LTB infection should be withdrawn from the study and receive 
appropriate TB or prophylaxis therapy.  
If a TB specialist excludes an active TB infection the subject can proceed with the IMP no earlier 
than 4 weeks after the start of an appropriate prophylactic therapy. 
Any presumptive diagnosis or diagnosis of a TB infection is a reportable event. Confirmed active 
TB must be reported as an SAE. The Investigator is to complete and submit the TB follow-up 
form provided. 
The subject should be transferred to the care of his/her physician and managed according to the 
best available standard of care. Subjects identified as having converted to active TB during the 
study must be withdrawn and scheduled to return for the ET Visit as soon as possible, but no 
later than the next scheduled study visit and complete all ET Visit assessments.  
The subject should be encouraged to complete a SFU Visit (20 weeks after the last dose of IMP). 
If infection with NTMB is identified during the study, the same procedure as for active TB 
acquired during the study must be followed. 
9.6.6 
Pregnancy testing 
A urine pregnancy test will be performed at any scheduled or unscheduled visit if there is 
suspicion of pregnancy and will be confirmed with a serum pregnancy test if the urine test is 
positive. 
Pregnancy test results must be negative prior to administering IMP. 
9.6.7 
Assessment of suicidal ideation and behavior 
Suicidal ideation and behavior will be assessed by trained study personnel using the eC-SSRS. 
This scale will be used to assess suicidal ideation and behavior that may occur during the study. 
The visits at which the eC-SSRS assessments will be performed are specified in the schedule of 
study assessments (Table 5‒1). 
The eC-SSRS is a standardized and validated instrument developed for the assessment of the 
severity and frequency of suicidal ideation and behavior (Posner et al, 2011; Mundt et al, 2010). 
Subjects respond to standardized clinical questions that are presented in a uniform fashion. The 
eC-SSRS defines 5 subtypes of suicidal ideation and behavior in addition to self-injurious 
behavior with no suicidal intent. The eC-SSRS takes approximately 3 to 10 minutes to complete. 
10 
ASSESSMENT OF EFFICACY 
Several assessments must be completed in order to determine the ACR response. These include 
the TJC and SJC based on 78 and 76 joints, respectively, PGADA, PhGADA, PtAAP, HAQ-DI, 
and CRP. The methods for the component measures will be described first, followed by ACR 
response and assessments used in secondary and other efficacy variables.  
The timing for all assessments is specified in the schedule of study assessments (Table 5‒1).  
10.1 
78/76 joint evaluation for ACR response 
The Principal Investigator, another delegated physician, or an appropriately qualified medical 
professional (based on local requirements) who has had documented training on how to perform 
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these assessments correctly assesses the following joints for tenderness: the distal 
interphalangeal, proximal interphalangeal and metacarpophalangeal joints of the hands, and 
metatarsophalangeal joints of the feet, the carpometacarpal and wrist joints (counted separately), 
the elbows, shoulders, acromioclavicular, sternoclavicular, hip, knee, talo-tibial, and midtarsal 
joints. All of these except for the hips are assessed for swelling.  
Artificial and ankylosed joints, as well as missing joints (ie, amputated joints), are excluded from 
both tenderness and swelling assessments.  
One dactylitic digit is to be counted as 1 swollen joint (instead of counting as 3 in the finger or 
2 in the toe). 
Table 10‒1 summarizes the swelling and tenderness grading criteria. 
Table 10‒1: Swelling and tenderness grading 
Grade 
Swelling response (76) 
Tenderness response (78) 
0 
None 
Not tender 
1 
Detectable synovial thickening 
Tenderness present 
 
10.2 
28 joint evaluation for determination of DAS28(CRP) 
The following 28 joints will be used for calculation of the DAS28(CRP). 
 Upper extremity (26)-bilateral shoulders, elbows, wrists (includes radiocarpal, and carpal and 
carpometacarpal bones considered as a single unit), metacarpophalangeal (MCP) I, II, III, IV, 
and V, thumb interphalangeals (IP), proximal interphalangeal (PIP) II, III, IV, and V  
 Lower extremity (2)-knees 
10.3 
Patient’s Global Assessment of Disease Activity 
Subjects will score their Global Assessment of Disease Activity using a visual analog scale 
(VAS) where 0 is “very good, no symptoms” and 100 is “very poor, severe symptoms”. 
The subject should be asked to consider both joint and skin components in their response to this 
question. 
10.4 
Physician’s Global Assessment of Disease Activity 
The Investigator will assess the overall status of the subject with respect to their PsA signs and 
symptoms and functional capacity (considering both joint and skin components) using a VAS 
where 0 is “very good, asymptomatic and no limitation of normal activities” and 100 is “very 
poor, very severe symptoms which are intolerable and inability to carry out all normal activities”. 
This assessment by the Investigator should be made blind to the PGADA. 
10.5 
Patient’s Assessment of Arthritis Pain 
The Patient’s Assessment of Arthritis Pain VAS or ‘Pain VAS’ is part of the ACR core set of 
measures in arthritis (Felson et al, 1993). Subjects will assess their arthritis pain using a VAS 
where 0 is “no pain” and 100 is “most severe pain”.  
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10.6 
Health Assessment Questionnaire-Disability Index score  
The HAQ-DI contains 20 items divided into 8 domains that measure: dressing and grooming, 
arising, eating, walking, hygiene, reach, grip, and common daily activities. Subjects are required 
to indicate the degree of difficulty they have experienced in each domain in the past week on a 
4-point scale that ranges from 0 (without difficulty) to 3 (unable to do). Any individual score of 
less than 2 is adjusted to 2 if the activity requires assistance from another individual or the use of 
an assistive device. The highest score in each category is then summed (0 to 24) and divided by 
the number of categories scored to give a score that ranges from 0 to 3.  
10.7 
CRP levels 
C-reactive protein levels will be analyzed by the central laboratory. 
10.8 
ACR20, ACR50, and ACR70 response 
The ACR20, ACR50, and ACR70 response rates are based on a 20%, 50%, and 70% or greater 
improvement relative to Baseline of PA0008 in the following measures: 
 TJC based on 78 joints 
 SJC based on 76 joints 
 3 of the 5 remaining core set measures: 
 PGADA 
 PhGADA 
 PtAAP 
 HAQ-DI 
 CRP 
10.9 
BSA-PSO 
The BSA palm method will be used for the evaluation of BSA affected by PSO as follows: 
The subject’s hand, including the palm, fingers and thumb, is used as the reference point for 
measuring how much of their skin is affected by PSO, representing roughly 1% of the body’s 
surface.  
 Subject’s palm=1% 
 Head and neck=10% (10 palms) 
 Upper extremities=20 % (20 palms) 
 Trunk=30% (30 palms) 
 Lower extremities=40 % (40 palms)  
Total BSA=100% 
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10.10 
Psoriasis Area and Severity Index (PASI) 
Psoriasis Area and Severity Index will be assessed in all subjects with study entry BSA affected 
by PSO ≥3% at Baseline of PA0008 determined by the method described in Section 10.9 (ie, the 
BSA palm method).  
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 percent area of involvement (BSA%) is estimated across 4 body areas; head, upper limbs, 
trunk, and lower limbs and then transferred into a grade (Table 10‒2).  
The Investigator assesses 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.  
Table 10‒2: 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 limbs  
Left, right, upper lower, flexor 
surface, extensor surface 
20%  
0 to 6 
Trunk 
Front, back, groin 
30%  
0 to 6 
Lower limbs  
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 at least 75%, 90%, and 100% 
improvement in the PASI score compared to Baseline in PA0008. Thereafter PASI will be 
analyzed for the purposes of determining response only in subjects with PSO involving at least 
3% of BSA at Baseline of PA0008.  
10.11 
MDA 
Minimal Disease Activity is a state of disease activity deemed a useful derived target of 
treatment by both the patient and physician, given current treatment possibilities and limitations. 
Criteria shown in Table 10‒3 covering all of the domains of the disease have been developed to 
determine whether or not a patient has reached MDA based on key outcome measures in PsA. 
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A subject is considered as having MDA if 5 or more of the following 7 criteria in Table 10‒3 are 
fulfilled:  
Table 10‒3: MDA criteria in PsA 
A subject is classified as in MDA when they meet 5 of 7 of the following criteria: 
 
Tender joint count ≤1 
 
Swollen joint count ≤1 
 
PASI ≤1 or BSA ≤3 
 
Patient pain VAS ≤15 
 
Patient global activity VAS ≤20 
 
HAQ ≤0.5 
 
Tender enthesial points ≤1 
 
BSA=body surface area; HAQ=Health Assessment Questionnaire; MDA=minimal disease activity; PASI=Psoriasis 
Area and Severity Index; VAS=visual analog scale 
Data sources: Mease, 2011; Coates et al, 2010 
 
In addition, a modified MDA will be determined using the criteria in Table 10‒3 by fulfilling the 
criterion PASI ≤1 or BSA ≤3 and 4 out of the 6 remaining criteria.  
10.12 
DAS28(CRP) 
The components for DAS28(CRP) include the TJC and SJC based on 28 joints (Section 10.2), 
CRP (Section 10.7) and the PGADA (Section 10.3). DAS28(CRP) is calculated as follows: 
 
10.13 
MASES 
The MASES is an index that measures the severity (ie, intensity and extent) of enthesitis through 
the assessment of 13 entheses (bilateral costochondral 1, costochondral 7, anterior superior iliac 
spine, posterior iliac spine, iliac crest and proximal insertion of the Achilles tendon sites, and the 
fifth lumbar vertebral body spinous process) (Heuft-Dorenbosch et al, 2003) each scored as 
0 or 1 and then summed for a possible score of 0 to 13. 
10.14 
LDI 
Dactylitis, the swelling of an entire digit related to articular and peri-articular inflammation, is a 
characteristic of inflammatory spondyloarthropathies, including PsA. Presence of dactylitis will 
be assessed using the LDI basic which evaluates for a ≥10% difference in the circumference of 
the digit compared to the opposite digit (Healy and Helliwell, 2007; Helliwell et al, 2005). This 
is then multiplied by the tenderness score, using a simple grading system (0=absent, 1=present). 
The digits involved and the matching contralateral digit will also be recorded at the same visits. 
10.15 
Hospital Anxiety and Depression Scale 
The HADS was chosen for its well-established psychometric properties and its use in clinical 
research on biological therapy in subjects with chronic plaque PSO (Langley et al, 2010; 
Dauden et al, 2009). The HADS scores for anxiety and for depression range from 0 to 21 with 
higher scores indicating worse state. A score below 8 is considered to be normal whereas a score 
of 15 and above is considered severe (Snaith and Zigmond, 1994). 




96
.0
1
ln
36
.0
014
.0
28
.0
56
.0
28










CRP
PGADA
SJC
TJC
CRP
DAS
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10.16 
PsAID-9 
The PsAID-9 is a patient-reported outcome measure for assessing the impact of PsA in 
9 physical and psychological domains, including pain, fatigue, skin problems, work and/or 
leisure activities, functional capacity, discomfort, sleep disturbance, coping, and 
anxiety/fear/uncertainty. Each domain is assessed with a single question using a 0 to 
10 numerical rating scale. Each domain score is multiplied by a weighting factor and the results 
are then summed to provide the total score. The total score ranges from 0 to 10, with higher 
scores indicating a worse status. The PsAID-9 demonstrated satisfactory psychometric properties 
in an international validation study; however, further validation is needed (Gossec et al, 2014). A 
score below 4 out of 10 is considered a patient-acceptable status. A change of 3 or more points is 
considered relevant absolute change.  
10.17 
SF-36 
The SF-36 (Version 2, standard recall) is a 36-item generic Health-Related Quality of Life 
(HRQoL) instrument that uses a recall period of 4 weeks. Items are grouped into 8 domains as 
follows: Physical Functioning (10 items), Role Physical (4 items), Bodily Pain (2 items), General 
Health (5 items), Vitality (4 items), Social Functioning (2 items), Role Emotional (3 items), 
Mental Health (5 items), and 1 item for perceived stability or change in health (Health 
Transition) during the last year. The concepts represented by these domains contribute to 
physical, mental, and social aspects of HRQoL. 
In addition to domain scores, the Physical Component Summary and Mental Component 
Summary scores are calculated from the 8 domains (excluding the Health Transition item). 
Component scores appreciate the impact of each domain on physical and mental health status 
(Maruish, 2011). Each of the 8 domain scores and the component summary scores range from 
0 to 100, with a higher score indicating a better health status. The 2 component summary scores 
are standardized with a mean of 50 and a standard deviation of 10 in the general US population.  
11 
ASSESSMENT OF IMMUNOGENICITY 
The Investigator or designee will obtain blood samples for measurement of bimekizumab plasma 
concentrations and antibodies to bimekizumab at the time points specified in Table 5‒1. When 
these samples are required at a visit during which the subject is dosed with IMP, the blood 
samples will be drawn prior to dosing. Samples should be drawn at the same time of the 
sampling for clinical laboratory tests. The time and date of collection will be recorded in the 
eCRF. Instructions pertaining to sample collection, processing, storage, labeling, and shipping 
are provided in the laboratory manual for this study. Any characterization of the 
anti-bimekizumab antibody response will be done using validated assays. Detailed information 
on sample analysis will be provided in a bioanalytical report. 
12 
STUDY MANAGEMENT AND ADMINISTRATION 
12.1 
Adherence to protocol 
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 subjects from any immediate hazard to their health and safety. In this case, this action 
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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 Clinical Project Manager 
of the sponsor within 24 hours and follow any local regulatory requirements. 
12.2 
Monitoring 
UCB (or designee) will monitor the study to meet the sponsor’s monitoring Standard Operating 
Procedures (SOPs), ICH-GCP guideline, and applicable regulatory requirements, and to ensure 
that study initiation, conduct, and closure are adequate. Monitoring of the study may be 
delegated by UCB to a CRO or a contract monitor. 
The investigator and his/her staff are expected to cooperate with UCB (or designee) and to be 
available during the monitoring visits to answer questions sufficiently and to provide any 
missing information. The investigator(s)/institution(s) will permit direct access to source 
data/documents for study-related monitoring, audits, IRB/IEC review, and regulatory 
inspection(s). 
The investigator will allow UCB (or designee) to periodically review all eCRFs and 
corresponding source documents (eg, hospital and laboratory records for each study participant). 
Monitoring visits will provide UCB (or designee) with the opportunity to evaluate the progress 
of the study, verify the accuracy and completeness of eCRFs, ensure that all protocol 
requirements, applicable authorities’ regulations, and investigator’s obligations are being 
fulfilled, and resolve any inconsistencies in the study records. 
12.2.1 
Definition of source data  
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, laboratory results, printouts, 
pharmacy records, care records, ECG or other printouts, completed scales, or quality of life 
questionnaires, for example. Source documents should be kept in a secure, limited access area. 
Sponsor or designee will review to ensure that computerized source documents produced by the 
site are compliant with Food and Drug Administration (FDA) Part 11 requirements and 
document appropriately. Source documents that are computer generated and stored electronically 
must be printed for review by the monitor (eg, ECG reports). Once printed, these copies should 
be signed and dated by the Investigator and become a permanent part of the subject’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). 
12.2.2 
Source data verification 
Source data verification ensures accuracy and credibility of the data obtained. During monitoring 
visits, reported data are reviewed with regard to being accurate, complete, and verifiable from 
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source documents (eg, subject files, recordings from automated instruments, tracings [ECG], 
x-ray films, laboratory notes). All data reported on the eCRF should be supported by source 
documents, unless otherwise specified in Section 12.2.1. 
12.3 
Data handling 
12.3.1 
Case Report form completion 
This study will use electronic data capture (EDC); the Investigator is responsible for prompt 
reporting of accurate, complete, and legible data in the eCRF and in all required reports. 
This study will also use an electronic device (Site Tablet) to capture patient reported outcomes. 
Serious AE reporting will be done using the SAE Report Form (see Section 9.2.2) while also 
entering the event in the appropriate eCRF section. The safety database and the clinical database 
will be reconciled during the study and discrepancies will be corrected as needed. 
The Investigator should maintain a list of personnel authorized to enter data into the eCRF. 
Access to the EDC will be given after training has been received. A training certificate will be 
provided and filed. 
Detailed instructions on the use of the EDC will be provided in the eCRF Completion 
Guidelines. 
Corrections made after the Investigator’s review and approval (by means of a 
password/electronic signature) will be re-approved by the Investigator. Any change or correction 
to the eCRF after saving must be accompanied by a reason for the change. 
12.3.2 
Database entry and reconciliation 
Case Report forms/external electronic data will be entered/loaded into a validated electronic 
database using a clinical data management system (CDMS). Computerized data cleaning checks 
will be used in addition to manual review to check for discrepancies and to ensure consistency of 
the data. This study is performed using EDC: the data are entered into the eCRFs once and are 
subsequently verified. 
An electronic audit trail system will be maintained within the CDMS to track all data changes in 
the database once the data have been saved initially into the system or electronically loaded. 
Regular backups of the electronic data will be performed. 
12.3.3 
Subject Screening and Enrollment log/Subject Identification Code list 
The subject’s screening and enrollment will be recorded in the Subject Screening and Enrollment 
Log. 
The investigator will keep a Subject Identification Code list. This list remains with the 
investigator and is used for unambiguous identification of each subject. 
The subject’s consent and enrollment in the study must be recorded in the subject’s medical 
record. These data should identify the study and document the dates of the subject’s 
participation. 
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12.4 
Termination of the study 
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 IRB/IEC should also be informed and provided with 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 of all 
unused IMP and other material in accordance with UCB procedures for the study. 
12.5 
Archiving and data retention 
The investigator will maintain adequate records for the study, including eCRFs, medical records, 
laboratory results, Informed Consent documents, drug dispensing and disposition records, safety 
reports, information regarding participants who discontinued, and other pertinent data. 
All essential documents are to be retained by the investigator until at least 2 years after the last 
approval of a marketing application in an ICH region and until there are no pending or 
contemplated marketing applications in an ICH region, or at least 2 years have elapsed since the 
formal discontinuation of clinical development of the IMP. These documents should be retained 
for a longer period, however, if required by the applicable regulatory requirement(s) or by an 
agreement with UCB (CPMP/ICH/135/95, 2002 [Section 4.9.5]). 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. 
12.6 
Audit and inspection 
The investigator will permit study-related audits mandated by UCB, after reasonable notice, and 
inspections by domestic or foreign regulatory authorities. 
The main purposes of an audit or inspection are to confirm that the rights and well-being of the 
subjects enrolled have been protected, that enrolled subjects (ie, signing consent and undergoing 
study procedures) are appropriate for the study, and that all data relevant for the evaluation of the 
IMP have been processed and reported in compliance with the planned arrangements, the 
protocol, investigational site, and IRB/IEC SOPs, ICH GCP, and applicable regulatory 
requirements. 
The investigator will provide direct access to all study documents, source records, and source 
data. If an inspection by a regulatory authority is announced, the investigator will immediately 
inform UCB (or designee). 
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12.7 
Good Clinical Practice 
Noncompliance with the protocol, ICH-GCP, or local regulatory requirements by the 
investigator, institution, institution staff, or designees of the sponsor will lead to prompt action 
by UCB to secure compliance. Continued noncompliance may result in the termination of the 
site’s involvement in the study. 
13 
STATISTICS 
A description of statistical methods follows and will be described in more detail in the Statistical 
Analysis Plan. 
13.1 
Definition of analysis sets 
The Enrolled Set (ES) will consist of all subjects who have given informed consent for PA0009. 
The Safety Set (SS) will consist of all subjects who receive at least 1 dose of the IMP in PA0009. 
The Full Analysis Set (FAS) will consist of all enrolled subjects who receive at least 1 dose of 
the IMP and have a valid measurement for at least 1 efficacy variable after PA0009 entry visit.  
13.2 
General statistical considerations 
Summary statistics will consist of frequency tables for categorical variables. For continuous 
variables, summary statistics will consist of number of available observations, arithmetic mean, 
standard deviation, median, minimum, and maximum unless stated otherwise. 
In general, summary statistics will be done by randomized treatment group and by treatment 
group at completion of PA0008 (ie, bimekizumab 160mg Q4W or bimekizumab 320mg Q4W).  
Two subpopulations will be defined for this study. Subpopulation 1 will consist of all subjects 
who do not receive rescue therapy according to the criteria outlined in Section 5.1.1. 
Subpopulation 2 will consist of all subjects who receive rescue therapy according to the criteria 
outlined in Section 5.1.1. Analyses of the primary and secondary variables will also be done on 
both subpopulations. 
Changes from Baseline will be calculated relative to the Baseline of PA0008. Variables 
measured at the start of PA0009 will be referred to as PA0009 entry values. 
13.3 
Planned safety analyses 
13.3.1 
Safety analyses 
Safety variables will be analyzed for all subjects in the SS.  
Adverse events will be coded according to the Medical Dictionary for Regulatory Activities. 
Adverse events will be summarized descriptively by treatment group at completion of PA0008, 
primary system organ class, high level term, and preferred term. This summary will include raw 
incidence rates, exposure-adjusted incidence rates (EAIRs) with associated 95% CIs, and 
exposure-adjusted event rates (EAERs) where the EAIR and EAER are expressed per 
100 patient-years of exposure.  
Patient exposure at risk will be defined as date of last administration of study medication – date 
of first administration of bimekizumab +20 weeks. If a subject has an adverse event with fatal 
outcome, patient exposure at risk is censored at the date of death.  
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The extent of exposure to study medication in PA0009 will be summarized using descriptive 
statistics by treatment group at completion of PA0008. 
Change from PA0008 Baseline values in vital signs variables will be summarized descriptively 
by visit and by treatment group at completion of PA0008. Change from PA0009 Laboratory 
Baseline values in clinical laboratory variables (hematology and biochemistry, excepting high-
sensitivity CRP) will be summarized descriptively by visit and by treatment group at completion 
of PA0008. 
Due to a change in laboratory vendor between PA0008 and PA0009, laboratory values 
(excepting CRP) will use the PA0009 Laboratory Baseline, defined as the earliest post-entry visit 
value recorded in PA0009. Change from PA0009 Laboratory Baseline will be calculated for 
these parameters. (The CRP values from the 2 analyzing laboratories have been calibrated, so 
change from PA0008 Baseline will be calculated for that parameter.) 
All safety analyses will be conducted for both subpopulations. 
13.4 
Planned efficacy analyses 
Secondary and other efficacy variables will be summarized for all subjects in the FAS; efficacy 
analyses will be performed over 104 weeks (2 years).  
Responder variables (eg, ACR20 response) will be derived relative to the Baseline of PA0008 
and summarized descriptively. Percentages will be summarized descriptively by visit, by 
randomized treatment group, and by treatment group at PA0009 entry. 
Change from Baseline of PA0008 of all continuous variables will be summarized descriptively 
by visit, by randomized treatment group, and by treatment group at completion of PA0008. 
13.4.1 
Subgroup analysis 
Subgroup analyses will be performed on the efficacy variables. The following variables for 
subgroup analyses will be defined: 
 Region 
 Disease duration 
 Previous tumor necrosis factor (TNF) inhibitor agent exposure 
 Concomitant DMARD status at Baseline of PA0008 
13.5 
Planned immunogenicity analyses 
Immunogenicity variables will be analyzed for all subjects in the SS.  
Bimekizumab plasma concentration and anti-bimekizumab antibody appearance will be 
summarized by visit, by randomized treatment group, and by treatment group at completion of 
PA0008. The first occurrence of anti-bimekizumab antibody positivity as well as persistent and 
transient anti-bimekizumab antibody positivity will be summarized by visit, by randomized 
treatment group, and by treatment group at completion of PA0008. Figures on persistent and 
transient anti-bimekizumab antibody positivity over time and on the relationship between 
ACR20 response and anti-bimekizumab antibody positivity over time will be produced. 
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13.6 
Other analyses 
Other variables will be summarized using descriptive statistics using the treatment group at 
completion of PA0008. 
13.7 
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 safety or efficacy outcomes for an individual 
subject. The criteria for identifying important protocol deviations will be defined within the 
appropriate protocol-specific document. Important protocol deviations will be reviewed as part 
of the ongoing data cleaning process. 
13.8 
Handling of dropouts or missing data 
Missing binary efficacy variables will be imputed using nonresponder imputation (NRI). In NRI, 
each subject with missing data or who has prematurely finished the study will be counted as a 
nonresponder. 
For missing continuous efficacy variables, a multiple imputation (MI) approach will be used. In 
MI, the missing value is replaced by a set of plausible values, where each value is a Bayesian 
draw from the conditional distribution of the missing data given the observed data. 
Non-monotone missing data (ie, intermittent missing data) will be imputed several times with the 
Markov Chain Monte Carlo (MCMC) method and monotone missing data will be imputed using 
a monotone regression model. Each set of imputed data will then be summarized and the 
summaries will be combined into a single inference (Carpenter and Kenward, 2013). 
Safety data will not be imputed. 
As a sensitivity analysis, the ACR, PASI, LDI, MASES, and MDA efficacy variables will be 
analyzed based on observed data in addition to a sensitivity analysis based on multiple 
imputation of ACR component scores and PASI scores for the ACR and PASI response 
variables, respectively. Subjects with missing data or who have prematurely finished the study 
will be treated as missing. 
13.9 
Planned interim analysis and data monitoring 
No formal interim analysis is planned for this study. Additional data cuts may be prepared 
following regulatory requests or for publication purposes. 
13.10 
Determination of sample size 
There is no formal sample size for this study. The sample size is determined by the number of 
subjects eligible for PA0009 and rolling over from PA0008. Up to 200 subjects from PA0008 
could be enrolled into this study. 
14 
ETHICS AND REGULATORY REQUIREMENTS 
14.1 
Informed consent 
Subject’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. 
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Prior to obtaining informed consent, information should be given in a language and at a level of 
complexity understandable to the subject in both oral and written form by the investigator (or 
designee). Each subject will have the opportunity to discuss the study and its alternatives with 
the investigator. 
Prior to participation in the study, the Informed Consent form should be signed and personally 
dated by the subject and by the person who conducted the informed consent discussion 
(investigator or designee). The subject must receive a copy of the signed and dated Informed 
Consent form. As part of the consent process, each subject must consent to direct access to 
his/her medical records for study-related monitoring, auditing, IRB/IEC review, and regulatory 
inspection. 
If the Informed Consent form 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 Informed Consent form by the IRB/IEC and use of the amended form. 
All studies conducted at centers in the United States must include the use of a Health Insurance 
Portability and Accountability Act Authorization form. 
The subject may withdraw his/her consent to participate in the study at any time. A subject is 
considered as enrolled in the study when he/she has signed the Informed Consent form. An eCRF 
must not be started, nor may any study specific procedure be performed for a given subject, 
without having obtained his/her written consent to participate in the study. 
14.2 
Subject identification cards 
Upon signing the Informed Consent and Assent form (as applicable), the subject will be provided 
with a subject identification card in the language of the subject. The investigator will fill in the 
subject identifying information and medical emergency contact information. The investigator 
will instruct the subject to keep the card with him/her at all times. 
14.3 
Institutional Review Boards and Independent Ethics 
Committees 
The study will be conducted under the auspices of an IRB/IEC, as defined in local regulations, 
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, Informed 
Consent form, Investigator’s Brochure, investigator’s curriculum vitae (if applicable), 
advertisement (if applicable), and all other subject-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 human subjects or others, and any protocol deviations, 
to eliminate immediate hazards to subjects. 
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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 subjects. 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 subject 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 each concerned country. Where applicable, 
investigators are to provide the sponsor (or its representative) with evidence of such IRB/IEC 
notification. 
14.4 
Subject privacy 
UCB staff (or designee) will affirm and uphold the subject’s confidentiality. Throughout this 
study, all data forwarded to UCB (or designee) will be identified only by the subject 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 
subject’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 subject’s study participation, and autopsy reports for deaths 
occurring during the study). 
14.5 
Protocol amendments 
Protocol changes may affect the legal and ethical status of the study and may also affect the 
statistical evaluations of sample size and the likelihood of the study fulfilling its primary 
objective. 
Significant changes to the protocol will only be made as an amendment to the protocol and must 
be approved by UCB, the IRB/IEC, and the regulatory authorities (if required), prior to being 
implemented. 
15 
FINANCE, INSURANCE, AND PUBLICATION 
Insurance coverage will be handled according to local requirements. 
Finance, insurance, and publication rights are addressed in the investigator and/or CRO 
agreements, as applicable. 
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16 
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placebo-controlled phase III trial. J Am Acad Dermatol. 2010;63(3):457-65. 
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17 
APPENDICES 
17.1 
Markedly abnormal laboratory values 
Table 17-1: Definitions of markedly abnormal hematology values 
Parameter (RCTC units) 
Markedly Abnormal Definition 
Low 
High 
Hemoglobin (g/dL) 
<LLN 
AND 
>2.0 decrease from Baseline 
N/A 
Hemoglobin (g/dL) 
<8.0 
N/A 
Leukocytes (total x 1000) 
<2.0 
N/A 
Lymphocytes (x 1000) 
<0.5 
N/A 
Neutrophils (x 1000) 
<1.0a 
N/A 
Platelets (x 1000) 
<50 
N/A 
LLN=lower limit of normal; N/A = Not Applicable; RCTC= Rheumatology Common Toxicity Criteria 
Data source: modified from Appendix Rheumatology Common Toxicity Criteria v.2.0 presented in 
Woodworth et al, 2007 
a Withdrawal criteria for neutrophils is <0.5 (Section 6.3). 
 
Table 17‒2: Definitions of markedly abnormal biochemistry values 
Parameter (RCTC units) 
Markedly Abnormal Definition 
Low  
High 
Alkaline Phosphatase 
N/A 
>3 x ULN 
ALT 
N/A 
>3 x ULN 
AST 
N/A 
>3 x ULN 
Calcium (mg/dL) 
<7.0 
>12.5 
Creatinine (mg/dl) 
N/A 
>1.8 x ULN 
Glucose (mg/dL) 
<40 
>250 
Potassium (mmol/L) 
<3.0 
>6.4 
Sodium (mmol/L) 
<125 
N/A 
Total bilirubin 
N/A 
≥2 x ULN 
Uric acid 
N/A 
≥3 x ULN 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; N/A=Not applicable; RCTC= Rheumatology 
Common Toxicity Criteria; ULN=upper limit of normal 
Data source: modified from Appendix Rheumatology Common Toxicity Criteria v.2.0 presented in 
Woodworth et al, 2007 
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17.2 
Protocol Amendment 1 
Rationale for the amendment 
The purpose of this amendment is the following: 
 To provide clarification that ACR and PASI responses are compared to both Baseline of 
PA0008 and PA0009 entry values. 
 To correct language regarding administration of live, inactivated vaccinations.  
 To remove inclusion of a Data Monitoring Committee.  
 To clarify guidance for Investigators when scoring injected joints.    
Modifications and changes 
Global changes 
No global changes have been made. Specific changes are listed below.  
Specific changes 
Change #1 
List of Abbreviations 
The following abbreviation has been deleted: 
DMC  
 
Data Monitoring Committee 
Change #2 
Summary, paragraph 6, sentence 2 
The secondary efficacy variables include the American College of Rheumatology 20% (ACR20) 
response at Week 48 (with a responder defined as a subject with an improvement from Baseline 
of ≥20% in the swollen and tender joint counts and at least 3 of the other 5 components of the 
core set of American College of Rheumatology [ACR] response measures), American College of 
Rheumatology 50% (ACR50) response at Week 48; American College of Rheumatology 70% 
(ACR70) response at Week 48, change from Baseline and PA0009 entry value in the Maastricht 
Ankylosing Spondylitis Enthesitis Index (MASES) at Week 48, change from Baseline and 
PA0009 entry value in the Leeds Dactylitis Index (LDI) at Week 48, the Psoriasis Area and 
Severity Index 75 (PASI75) response, and the Psoriasis Area and Severity Index 90 (PASI90) 
response at Week 48. 
Has been changed to: 
The secondary efficacy variables include the American College of Rheumatology 20% (ACR20) 
response at Week 48 (with a responder defined as a subject with an improvement from PA0008 
Baseline and PA0009 entry value of ≥20% in the swollen and tender joint counts and at least 3 
of the other 5 components of the core set of American College of Rheumatology [ACR] response 
measures), American College of Rheumatology 50% (ACR50) response at Week 48; American 
College of Rheumatology 70% (ACR70) response at Week 48, change from Baseline and 
PA0009 entry value in the Maastricht Ankylosing Spondylitis Enthesitis Index (MASES) at 
Week 48, change from Baseline and PA0009 entry value in the Leeds Dactylitis Index (LDI) at 
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Week 48, the Psoriasis Area and Severity Index 75 (PASI75) response, and the Psoriasis Area 
and Severity Index 90 (PASI90) response at Week 48. 
 
Change #3 
Section 7.8.1  
Permitted concomitant treatments (medications and therapies), bullet point 
item 3 
 Up to 1 injection per joint for up to 3 discrete joints is permitted per 12-month period. 
Injected joints are censored for the joint examination.  
Has been changed to: 
 Up to 1 injection per joint for up to 3 discrete joints is permitted per 12-month period. 
Investigators should follow the guidance in the CRF instructions for proper scoring of 
the injected joints. 
 
Change #4 
Section 7.8.2  
Prohibited concomitant treatments (medications and therapies), Vaccines, 
paragraph 1 
Administration of live, attenuated vaccines is not allowed during the conduct of the study or for 
20 weeks after the last dose of study drug. Administration of non-live, attenuated vaccines is 
allowed during the study at the discretion of the Investigator. 
Has been changed to: 
Administration of live, attenuated vaccines is not allowed during the conduct of the study or for 
20 weeks after the last dose of study drug. Administration of non-live, inactivated vaccines is 
allowed during the study at the discretion of the Investigator. 
 
Change #5 
Section 9.1.11  
Safety signal detection, paragraph 3 
In addition, an independent Data Monitoring Committee (DMC) will periodically review and 
monitor the safety data from this study and advise UCB. Details are provided in the DMC 
Charter. Cardiovascular and Neuropsychiatric Adjudication Committees will also periodically 
review and monitor the safety data from this study and advise UCB. Details are provided in the 
Adjudication Committee Charters. 
Has been changed to: 
In addition, Cardiovascular and Neuropsychiatric Adjudication Committees will also periodically 
review and monitor the safety data from this study and advise UCB. Details are provided in the 
Adjudication Committee Charters. 
 
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Change #6 
Section 10.8  
ACR20, ACR50, and ACR70 response, paragraph 1 
The ACR20, ACR50, and ACR70 response rates are based on a 20%, 50%, and 70% or greater 
improvement relative to Baseline of PA0008 in the following measures: 
Has been changed to: 
The ACR20, ACR50, and ACR70 response rates are based on a 20%, 50%, and 70% or greater 
improvement relative to Baseline of PA0008 and PA0009 entry values in the following 
measures: 
 
Change #7 
Section 10.10  
Psoriasis Area and Severity Index (PASI), paragraph 6 
The PASI75, PASI90, and PASI100 responses are based on at least 75%, 90%, and 100% 
improvement in the PASI score compared to Baseline in PA0008. Thereafter PASI will be 
assessed for the purposes of determining response only in subjects with PSO involving at least 
3% of BSA at study entry.  
Has been changed to: 
The PASI75, PASI90, and PASI100 responses are based on at least 75%, 90%, and 100% 
improvement in the PASI score compared to Baseline in PA0008 and PA0009 entry values. 
Thereafter PASI will be assessed for the purposes of determining response only in subjects with 
PSO involving at least 3% of BSA at study entry.  
 
Change #8 
Section 10.11  
MDA 
The following text was added beneath Table 10-3: 
In addition, a modified MDA will be determined using the criteria in Table 10-3 by 
fulfilling the criterion PASI ≤1 or BSA ≤3 and 4 out of the 6 remaining criteria.
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17.3 
Protocol Amendment 2 
Rationale for the amendment 
The purpose of this substantial amendment is as follows:  
 To update the study contact details for the sponsor study physician and clinical trial 
biostatistician. 
 Amend the open-label treatment period for clarification, as per request from the regulatory 
agency. 
 Amend the study procedures and assessments to be performed at the Safety Follow-up visit. 
Efficacy assessments were removed since they are not required at the SFU visit. 
 Include additional wording to the inclusion criteria (criterion #5) listing acceptable methods 
of contraception for female subjects. 
 Amend the exclusion criteria (criterion #2) to include further clarification on when to consult 
the medical monitor.  
 To revise the withdrawal criteria section to provide instructions for the management of 
subjects with newly diagnosed IBD or with IBD flares during the study. 
 To revise and clarify the SAE criteria for pregnancy for consistency. 
 Amend the table for identification/exclusion of alternative etiology to include ALT and AST. 
 Amend and remove wording from the criteria determined for handling of dropouts or missing 
data. 
Modifications and changes 
Global change 
The following global change was made for the duration of the open-label treatment period and 
period for administration of bimekizumab:  
104 weeks (2 weeks)  
Has been changed to: 
100104 weeks (~2 weeks) 
 
Specific changes 
Change #1 
List of Abbreviations 
The following abbreviations have been added:  
IBD 
Inflammatory Bowel Disease 
IUD 
intrauterine device 
IUS 
intrauterine hormone-releasing system 
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MCMC 
Markov Chain Monte Carlo 
RCTC 
Rheumatology Common Toxicity Criteria 
 
Change #2 
Sponsor Study Physician 
Name: 
, MD 
Address: 
UCB BIOSCIENCES Inc. 
8010 Arco Corporate Drive 
Raleigh, NC 27617 
UNITED STATES 
Phone: 
 (office) 
 (mobile) 
Has been changed to:  
Name: 
 MD, MSc, PhD 
, MD 
Address: 
UCB Pharma Ltd. UCB BIOSCIENCES Inc. 
208 Bath Road 8010 Arco Corporate Drive 
Slough, SL1 3WE Raleigh, NC 27617 
UNITED KINGDOM UNITED STATES 
Phone: 
 (office) 
 (mobile) 
 
Change #3 
Study contact information 
Clinical Trial Biostatistician 
Name: 
Dr. 
, Senior Biostatistician 
Address: 
UCB BIOSCIENCES GmbH 
Alfred-Nobel-Str.10 
40789 Monheim am Rhein 
GERMANY 
Phone: 
 
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Has been changed to:  
Clinical Trial Biostatistician 
Name: 
, Senior 
Biostatistician 
Address: 
UCB BIOSCIENCES GmbH 
Alfred-Nobel-Str.10 
0789 Monheim am Rhein 
GERMANY  
Phone: 
 
 
Change #4 
Section 5.1 Study design, paragraph 3 
Additionally, as described in (Section 5.1.1), other treatments may be used in addition to 
bimekizumab per Investigator discretion. Subjects not responding to treatment may be 
withdrawn from the study at the discretion of the Investigator. 
Has been changed to:  
Additionally, as described in (Section 5.1.1), other treatments may be used in addition to 
bimekizumab per Investigator discretion. Subjects not responding to treatment may be 
withdrawn from the treatment and study at the discretion of the Investigator. 
 
Change #5 
Section 5.1.2 Study duration per subject  
The study duration for each subject is estimated to be up to a maximum of 120 weeks: 
 Open Label Treatment Period: up to 104 weeks (2 years) 
 SFU Visit: 20 weeks after the final dose of bimekizumab 
The subject may remain in the study until the study ends after 2 years (104 weeks of treatment), 
until the Sponsor decides to close the study, or until bimekizumab development is stopped by the 
Sponsor, whichever comes first. The Sponsor may consider transitioning the subject into another 
bimekizumab study or program. 
The end of the study is defined as the date of the last visit of the last subject in the study.  
Has been changed to:  
The study duration for each subject is estimated to be up to a maximum of 120 weeks: 
 Open-Label Treatment Period: up to 104100 weeks (~2 years) 
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 SFU Visit: 20 weeks after the final dose of bimekizumab 
The subject may remain in the study until the study ends after 2 years (104 weeks of treatment) 
120 weeks, until the Sponsor decides to close the study, or until bimekizumab development is 
stopped by the Sponsor, whichever comes first. The Sponsor may consider transitioning the 
subject into another bimekizumab study or program. 
The end of the study is defined as the date of the last visit of the last subject in the study.  
 
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Change #6 
Section 5.2 Schedule of study assessments, Table 5-1 
 
 
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Has been changed to:  
 
 
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Change #7 
Section 5.2 Schedule of study assessments, Table 5-1, Footnote ‘l’ 
l 
It is recommended that the QuantiFERON TB GOLD test be performed. This assessment will 
be performed at study entry, unless an IGRA negative result is available less than 4 weeks prior 
to the first dose of open-label bimekizumab. 
Has been changed to:  
l 
It is recommended that the QuantiFERON TB GOLD test Test be performed. This 
assessment will be performed at study entry, unless an IGRA negative result is available less 
than 64 weeks prior to the first dose of open-label bimekizumab. 
 
Change #8 
Section 6.1 Inclusion criteria (criterion #5) 
5. Female subjects must be postmenopausal (at least 1 year), 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 until 20 weeks after last administration of study 
medication, and have a negative pregnancy test at the last visit of PA0008. 
Male subjects with a partner of childbearing potential must be willing to use a condom when 
sexually active, up until 20 weeks after the last administration of study medication 
(anticipated 5 half-lives). 
Has been changed to:  
5. Female subjects must be postmenopausal (at least 1 year), 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 until 20 weeks after last administration of study 
medication, and have a negative pregnancy test at the last visit of PA0008. 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 (IUD) 
 intrauterine hormone-releasing system (IUS) 
 bilateral tubal occlusion 
 vasectomized partner  
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 sexual abstinence if it is in accordance with a subject’s preferred and common 
lifestyle. Subjects who use abstinence as a form of birth control must agree to 
abstain from heterosexual intercourse until 20 weeks after the last dose of IMP. 
Study personnel must confirm the continued use of abstinence is still in accordance 
with the subject’s lifestyle at regular intervals during the study. 
Male subjects with a partner of childbearing potential must be willing to use a condom when 
sexually active, up until 20 weeks after the last administration of study medication 
(anticipated 5 half-lives). 
 
Change #9 
Section 6.2 Exclusion criteria (criterion #2) 
2. Subjects with any current sign or symptom that may indicate a medically significant active 
infection (except for the common cold) or has had an infection requiring systemic antibiotics 
within 2 weeks of study entry. 
Has been changed to:  
2. Subjects with any current sign or symptom that may indicate a medically significant active 
infection (except for the common cold) or has had an infection requiring systemic antibiotics 
within 2 weeks of study entry. The medical monitor must be consulted prior to subject’s 
entry into PA0009 in such cases. 
 
Change #10 
Section 6.3 Withdrawal criteria 
The following was added to the withdrawal criteria: 
12. Subjects with newly diagnosed inflammatory bowel disease (IBD) or with IBD flares 
during the study must: 
 Be referred, as appropriate, to a health care professional treating IBD, such as a 
gastroenterologist 
 Discontinue IMP and be followed-up until resolution of active IBD symptoms 
If IBD flares increase in severity or frequency during the study, the Investigator should use 
clinical judgment in deciding whether the subject should continue in the study and contact 
the Medical Monitor and UCB study physician to confirm the subject's suitability for 
continued participation in the study. 
 
Change #11 
Section 8.9 SFU Visit (20 weeks after the final dose of IMP) 
The following procedures or assessments will be completed: 
 Record concomitant medications 
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 Record AEs 
 eC-SSRS 
 HADS  
 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3%, determine the PASI 
 Determine the MASES 
 Determine the LDI 
 Perform the PhGADA 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Perform an IGRA TB test 
 Record visit in the IXRS 
Has been changed to:  
The following procedures or assessments will be completed: 
 Record concomitant medications 
 Record AEs 
 eC-SSRS 
 HADS  
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 Administer the HAQ-DI  
 Administer the SF-36 
 Administer the PGADA 
 Administer the PtAAP  
 Administer the PsAID-9  
 Administer the TB questionnaire  
 Measure vital signs (temperature, pulse, and BP) 
 Measure body weight 
 Perform a physical examination, including an evaluation for signs and symptoms of active 
TB and risk for exposure to TB 
 Perform TJC/SJC 
 Determine BSA affected by PSO using the BSA palm method 
 If the BSA affected by PSO is ≥3%, determine the PASI 
 Determine the MASES 
 Determine the LDI 
 Perform the PhGADA 
 Collect samples for hematology/biochemistry 
 If there has been a delay in menses, perform a urine pregnancy test 
 Collect blood sample for CRP 
 Collect blood sample for bimekizumab plasma concentrations and anti bimekizumab 
antibody detection 
 Perform an IGRA TB test 
 Record visit in the IXRS 
 
Change #12 
Section 9.1.1 Definition of AE 
The following was added to the definition of AEs: 
Adverse events that occurred during the PA0008 lead-in study and are still deemed 
ongoing at the time of enrolment (signed ICF) will be captured in the database and 
followed up, as described in Section 9.1.6. 
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Change #13 
Section 9.1.8 Pregnancy, paragraph 5 
A pregnancy becomes an SAE in the following circumstances: miscarriage, abortion (elective for 
a medical condition or spontaneous), unintended pregnancy after hormonal contraceptive failure 
(if the hormonal contraceptive was correctly used), ectopic pregnancy, fetal demise, or any 
congenital anomaly/birth defect of the baby. Those SAEs must be additionally reported using the 
Investigator SAE Report Form. 
Has been changed to:  
A pregnancy becomes an SAE in the following circumstances: miscarriage, elective 
abortion when medically indicated (e.g. when pregnancy is endangering life or health of 
woman or when fetus will be born with severe abnormalities), unintended pregnancy after 
hormonal contraceptive failure (if the hormonal contraceptive was correctly used), ectopic 
pregnancy, fetal demise, or any congenital anomaly/birth defect of the baby. Those SAEs 
must be additionally reported using the Investigator SAE Report form. 
 
Change #14 
Section 9.5.1.4 Testing: identification/exclusion of alternative etiology, Table 9-4 (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 
Toxicology screena 
Chemistry 
Amylase 
If total bilirubin ≥1.5xULN, obtain fractionated bilirubin to obtain % direct 
bilirubin 
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Serum CPK and LDH to evaluate possible muscle injury causing transaminase 
elevation 
Additional 
Prothrombin time/INRb 
Serum pregnancy test 
PK sample 
ALT=alanine aminotransferase; CPK=creatine phosphokinase; HBcAb-IgM=hepatitis B core antibody-IgM; 
HBsAg=hepatitis B surface antigen; IgM=immunoglobulin M; INR=international normalized ratio; LDH=lactate 
dehydrogenase; PDILI=potential drug-induced liver injury; PK=pharmacokinetic; RNA=ribonucleic acid; 
ULN=upper limit of normal 
a For detecting substances (ie, amphetamines, benzodiazepines, opioids, marijuana, cocaine, phencyclidine, and 
tricyclic antidepressants), additional tests may be performed based on the Investigator’s medical judgment and 
patient’s history. 
b Measured only for subjects with ALT >8xULN, 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 (>5%), rash, and fever (without clear alternative 
cause). 
Has been changed to:  
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 
Toxicology screena 
Chemistry 
Amylase 
ALT, AST 
If total bilirubin ≥1.5xULN, obtain fractionated bilirubin to obtain % direct 
bilirubin 
Serum CPK and LDH to evaluate possible muscle injury causing transaminase 
elevation 
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Additional 
Prothrombin time/INRb 
Serum pregnancy test 
PK sample 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; CPK=creatine phosphokinase; HBcAb-
IgM=hepatitis B core antibody-IgM; HBsAg=hepatitis B surface antigen; IgM=immunoglobulin M; 
INR=international normalized ratio; LDH=lactate dehydrogenase; PDILI=potential drug-induced liver injury; 
PK=pharmacokinetic; RNA=ribonucleic acid; ULN=upper limit of normal 
a For detecting substances (ie, amphetamines, benzodiazepines, opioids, marijuana, cocaine, phencyclidine, and 
tricyclic antidepressants), additional tests may be performed based on the Investigator’s medical judgment and 
patient’s history. 
b Measured only for subjects with ALT >8xULN, 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 (>5%), rash, and fever (without clear alternative 
cause). 
 
Change #15 
Section 9.6.5  Tuberculosis and TB risk factor assessment and management, 2nd paragraph 
Prior to administration of IMP, subjects will have an IGRA test (QuantiFERON TB GOLD is 
recommended) and examination for signs and symptoms of TB unless an IGRA negative result is 
available less than 4 weeks prior to the first dose of open label bimekizumab. In addition, each 
subject will complete a TB questionnaire with questions directed at symptoms of TB and 
potential exposure to TB. 
Has been changed to: 
Prior to administration of IMP, subjects will have an IGRA test (QuantiFERON TB TestGOLD 
is recommended) and examination for signs and symptoms of TB unless an IGRA negative result 
is available less than 64 weeks prior to the first dose of open label bimekizumab. In addition, 
each subject will complete a TB questionnaire with questions directed at symptoms of TB and 
potential exposure to TB. 
 
Change #16 
Section 9.6.5.1 Tuberculosis assessment by IGRA 
During conduct of the study, the TB assessment by IGRA (QuantiFERON TB Test is 
recommended) will be performed at study entry (unless an IGRA negative result is available less 
than 4 weeks prior to the first dose of open-label bimekizumab) and should be repeated at 
Week 48, Week 96, and SFU Visits for all subjects. The test results will be reported as positive, 
negative, or indeterminate. UCB also recommends that a TB specialist be consulted where TB 
(latent or active) is suspected or if there are doubts regarding test results. If latent or active TB is 
identified, subject must undergo appropriate study-specified withdrawal procedures. 
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Has been changed to: 
During conduct of the study, the TB assessment by IGRA (QuantiFERON TB GOLDTest is 
recommended) will be performed at study entry (unless an IGRA negative result is available less 
than 4 weeks prior to the first dose of open-label bimekizumab) and should be repeated at 
Week 48, Week 96, and SFU Visits for all subjects. The test results will be reported as positive, 
negative, or indeterminate. UCB also recommends that a TB specialist be consulted where TB 
(latent or active) is suspected or if there are doubts regarding test results. If latent or active TB is 
identified, subject must undergo appropriate study-specified withdrawal procedures. 
 
Change #17 
Section 13.8  Handling of dropouts or missing data, paragraph 3  
Missing binary efficacy variables will be imputed using nonresponder imputation (NRI). In NRI, 
each subject with missing data or who has prematurely finished the study will be counted as a 
nonresponder. 
For missing continuous efficacy variables, a multiple imputation (MI) approach will be used. In 
MI, the missing value is replaced by a set of plausible values, where each value is a Bayesian 
draw from the conditional distribution of the missing data given the observed data. 
Non-monotone missing data (ie, intermittent missing data) will be imputed several times with the 
Markov Chain Monte Carlo (MCMC) method and monotone missing data will be imputed using 
a monotone regression model. Each set of imputed data will then be summarized and the 
summaries will be combined into a single inference (Carpenter and Kenward, 2013). 
Imputation of efficacy data will be performed for only those assessments that the patient had in 
PA0008. Safety data will not be imputed. 
As a sensitivity analysis, all efficacy variables will be analyzed based on observed data. Subjects 
with missing data or who have prematurely finished the study will be treated as missing. 
Has been changed to: 
Missing binary efficacy variables will be imputed using nonresponder imputation (NRI). In NRI, 
each subject with missing data or who has prematurely finished the study will be counted as a 
nonresponder. 
For missing continuous efficacy variables, a multiple imputation (MI) approach will be used. In 
MI, the missing value is replaced by a set of plausible values, where each value is a Bayesian 
draw from the conditional distribution of the missing data given the observed data. Non 
monotone missing data (ie, intermittent missing data) will be imputed several times with the 
Markov Chain Monte Carlo (MCMC) method and monotone missing data will be imputed using 
a monotone regression model. Each set of imputed data will then be summarized and the 
summaries will be combined into a single inference (Carpenter and Kenward, 2013). 
Imputation of efficacy data will be performed for only those assessments that the patient had in 
PA0008. Safety data will not be imputed. 
As a sensitivity analysis, all efficacy variables will be analyzed based on observed data. Subjects 
with missing data or who have prematurely finished the study will be treated as missing. 
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Change #18 
Section 17.1  Markedly abnormal laboratory values, Tables 17-1 (Definitions of markedly 
abnormal hematology values) and 17-2 (Definitions of markedly abnormal biochemistry values) 
Amended units in both table headers:  
Parameter (SI units) 
Markedly Abnormal Definition 
Low 
High 
  Has been changed to: 
Parameter (SIRCTC units) 
Markedly Abnormal Definition 
Low 
High 
 
Change #19 
Section 17.1  Markedly abnormal laboratory values, Table 17-1 (Definitions of markedly 
abnormal hematology values), abbreviations in table footer: 
LLN=lower limit of normal; N/A = Not Applicable; SI = standard international 
Has been changed to: 
LLN=lower limit of normal; N/A = Not Applicable; SI = standard international RCTC= 
Rheumatology Common Toxicity Criteria 
 
Change #20 
Section 17.1  Markedly abnormal laboratory values, Table 17-2 (Definitions of markedly 
abnormal biochemistry values), abbreviations in table footer: 
ALT=alanine aminotransferase; AST=aspartate aminotransferase; N/A=Not applicable; 
SI=standard international; ULN=upper limit of normal 
Has been changed to: 
LLN=lower limit of normal; N/A = Not Applicable; SI=standard international RCTC= 
Rheumatology Common Toxicity Criteria 
 
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17.4 
Protocol Amendment 3 
Rationale for the amendment 
The purpose of this nonsubstantial amendment is as follows:  
 To clarify that PASI will be analyzed in subjects with PSO involving at least 3% of BSA at 
Baseline of PA0008  
 To update study contact information 
 To make minor spelling, editorial, and formatting changes throughout the document  
Modifications and changes 
Global change 
The following global changes were made:  
 The company name was changed from UCB Biopharma SPRL to UCB Biopharma SRL 
 The term “legal representative” was deleted from protocol, as it is not applicable to 
PA0009 
 Throughout the protocol "Baseline" was changed to "Baseline of PA0008" or similar 
wording 
Specific changes 
Change #1 
Study Contact Information 
Sponsor 
UCB BIOPHARMA SPRL 
Allée de la Recherche 60 
1070 Brussels 
BELGIUM 
Sponsor Study Physician 
Name: 
, MD, MSc, PhD  
Address: 
UCB Pharma Ltd. 
208 Bath Road  
Slough, SL1 3WE 
UNITED KINGDOM  
Phone: 
 
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Clinical Project Manager 
Name: 
, Clinical Project Manager 
Address: 
UCB BIOSCIENCES Inc. 
8010 Arco Corporate Drive 
Raleigh, NC  27617 
UNITED STATES 
Phone: 
 
Clinical Trial Biostatistician 
Name: 
  
Address: 
UCB BIOSCIENCES GmbH 
Alfred-Nobel-Strasse 10 
40789 Monheim am Rhein 
GERMANY 
Phone: 
 
 
Has been changed to: 
Sponsor 
UCB BIOPHARMA SPRLSRL 
Allée de la Recherche 60 
1070 Brussels 
BELGIUM 
Sponsor Study Physician 
Name: 
, MD, MSc, PhD 
, MD 
Address: 
UCB Pharma Ltd. 
208 Bath Road  
Slough, SL1 3WE 
UNITED KINGDOM  
Phone: 
  
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Clinical Project Manager 
Name: 
, Clinical Project Manager 
 
Address: 
UCB BIOSCIENCES Inc. 
8010 Arco Corporate Drive 208 Bath Road 
Raleigh, NC  27617 Sough, SL1 3WE 
UNITED STATES UNITED KINGDOM 
Phone: 
 
Clinical Trial Biostatistician 
Name: 
 
Address: 
UCB BIOSCIENCES GmbH  
Alfred-Nobel-Strasse 10 208 Bath Road 
40789 Monheim am Rhein Slough SL1 3WE 
GERMANY UNITED KINGDOM 
Phone: 
 
 
Change #2 
List of Abbreviations 
The following abbreviations were added:  
PFS 
prefilled syringe 
TEAE 
treatment-emergent adverse event 
 
Change #3 
Section 1 Summary, paragraphs 5 and 6 
The primary objective of PA0009 is to assess the long-term safety and tolerability of 
bimekizumab administered over a period of up to 100 weeks (~2 years). The primary safety 
variables are the incidences of adverse events (AEs) and serious adverse events (SAEs). 
The secondary objective is to assess the long-term efficacy of bimekizumab over a period of up 
to 104 weeks (~2 years). The secondary efficacy variables include the American College of 
Rheumatology 20% (ACR20) response at Week 48 (with a responder defined as a subject with 
an improvement from PA0008 Baseline and PA0009 entry value of ≥20% in the swollen and 
tender joint counts and at least 3 of the other 5 components of the core set of American College 
of Rheumatology [ACR] response measures), American College of Rheumatology 50% 
(ACR50) response at Week 48; American College of Rheumatology 70% (ACR70) response at 
Week 48, change from Baseline and PA0009 entry value in the Maastricht Ankylosing 
Spondylitis Enthesitis Index (MASES) at Week 48, change from Baseline and PA0009 entry 
value in the Leeds Dactylitis Index (LDI) at Week 48, the Psoriasis Area and Severity Index 75 
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(PASI75) response, and the Psoriasis Area and Severity Index 90 (PASI90) response at Week 48. 
The secondary safety variable is the withdrawal due to AEs.  
Has been changed to:  
The primary objective of PA0009 is to assess the long-term safety and tolerability of 
bimekizumab administered over a period of up to 100 weeks (~2 years). The primary safety 
variables are the incidences of treatment-emergent adverse events (TEAEs) and 
treatment-emergent serious adverse events (SAEs). 
The secondary objective is to assess the long-term efficacy of bimekizumab over a period of up 
to 104 weeks (~2 years). The secondary efficacy variables include the American College of 
Rheumatology 20% (ACR20) response at Week 48 (with a responder defined as a subject with 
an improvement from PA0008 Baseline and PA0009 entry value of ≥20% in the swollen and 
tender joint counts and at least 3 of the other 5 components of the core set of American College 
of Rheumatology [ACR] response measures), American College of Rheumatology 50% 
(ACR50) response at Week 48; American College of Rheumatology 70% (ACR70) response at 
Week 48, change from PA0008 Baseline and PA0009 entry value in the Maastricht Ankylosing 
Spondylitis Enthesitis Index (MASES) at Week 48, change from PA0008 Baseline and PA0009 
entry value in the Leeds Dactylitis Index (LDI) at Week 48, the Psoriasis Area and Severity 
Index 75 (PASI75) response, and the Psoriasis Area and Severity Index 90 (PASI90) response at 
Week 48. The secondary safety variable is the withdrawal due to AEs TEAEs.  
 
Change #4 
Section 4 Study Variables 
Changes from Baseline will be analyzed relative to the Baseline Visit of PA0008. Variables 
measured at the start of PA0009 will be referred to as PA0009 entry values. 
Has been changed to:  
All efficacy variables Change from Baseline will be analyzed relative to the Baseline Visit of 
PA0008. Safety vVariables measured at the start of PA0009 will be referred to as PA0009 entry 
values. 
 
Change #5 
Section 4.1.1 Primary safety variables 
The primary safety variables are the incidences of AEs and SAEs. 
Has been changed to:  
The primary safety variables are the incidences of TEAEs and treatment-emergent SAEs. 
 
Change #6 
Section 4.2.1 Secondary safety variable 
The secondary safety variable is the withdrawal due to AEs. 
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Has been changed to:  
The secondary safety variable is the withdrawal due to AEsTEAEs. 
 
Change #7 
Section 4.2.2 Secondary efficacy variables 
The secondary efficacy variables are:  
 ACR20, ACR50, and ACR70 response at Week 48 
 Change from Baseline and PA0009 entry value in MASES at Week 48 
 Change from Baseline and PA0009 entry value in the LDI at Week 48 
 PASI75 and PASI90 response at Week 48 
Has been changed to:  
The secondary efficacy variables are:  
 ACR20, ACR50, and ACR70 response at Week 48 
 Change from Baseline of PA0008 and PA0009 entry value in MASES at Week 48 
 Change from Baseline of PA0008 and PA0009 entry value in the LDI at Week 48 
 PASI75 and PASI90 response at Week 48 
 
Change #8 
Section 4.3.1 Safety variables 
Other safety variables are listed below. 
 
Change from Baseline and PA0009 entry value in clinical laboratory variables (hematology 
and biochemistry) 
 
Change from Baseline and PA0009 entry value in vital signs (pulse, temperature, and blood 
pressure) and body weight 
Has been changed to:  
Other safety variables are listed below. 
 
Change from Baseline and PA0009 entry value in Laboratory Baseline (defined as the 
earliest date in PA0009 at or prior to PA0009 Week 12) for clinical laboratory variables 
(hematology and biochemistry, excepting high-sensitivity C-reactive protein [CRP]) at 
each visit) 
 
Change from Baseline of PA0008 and PA0009 entry value in vital signs (pulse, temperature, 
and blood pressure) and body weight 
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Change #9 
Section 4.3.2 Efficacy variables 
Other efficacy variables are listed below and will be evaluated at scheduled visits in accordance 
with the schedule of study assessments in Table 5-1. 
 ACR20, ACR50, and ACR70 response 
 PASI100 response 
 PASI75 and PASI90 response  
 Minimal Disease Activity (MDA) as defined in Table 10-3 
 Change from Baseline and PA0009 entry value in the Disease Activity Score-28 based on 
C-reactive protein (DAS28 [CRP]) by visit 
 Change from Baseline and PA0009 entry value in MASES 
 Change from Baseline and PA0009 entry value in the LDI 
 Change from Baseline and PA0009 entry value in Psoriatic Arthritis Impact of Disease 
(PsAID)-9 
 Change from Baseline and PA0009 entry value in Short Form 36-item Health Survey (SF-36) 
 Change from Baseline and PA0009 entry value in the Hospital Anxiety and Depression Scale 
(HADS): HADS-Anxiety (HADS-A) and HADS-Depression (HADS-D) scores 
 Depression and anxiety status “normal” as defined by HADS-D and HADS-A <8 
Has been changed to: 
Other efficacy variables are listed below and will be evaluated at scheduled visits in accordance 
with the schedule of study assessments in Table 5-1. 
 ACR20, ACR50, and ACR70 response 
 PASI75, PASI90, and PASI100 response 
 PASI75 and PASI90 response  
 Minimal Disease Activity (MDA) as defined in Table 10-3 
 Change from Baseline of PA0008 and PA0009 entry value in the Disease Activity Score-28 
based on C-reactive protein (DAS28 [CRP]) by visit 
 Change from Baseline of PA0008 and PA0009 entry value in MASES 
 Change from Baseline of PA0008 and PA0009 entry value in the LDI 
 Change from Baseline of PA0008 and PA0009 entry value in Psoriatic Arthritis Impact of 
Disease (PsAID)-9 
 Change from Baseline of PA0008 and PA0009 entry value in Short Form 36-item Health 
Survey (SF-36) 
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 Change from Baseline of PA0008 and PA0009 entry value in the Hospital Anxiety and 
Depression Scale (HADS): HADS-Anxiety (HADS-A) and HADS-Depression (HADS-D) 
scores 
 Depression and anxiety status “normal” as defined by HADS-D and HADS-A <8 
 
Change #10 
Table 5-1: Schedule of study assessments (footnote a) 
a Visit windows are ±7 days from the scheduled visit day (relative to the first dose) with a minimum of 21 days and 
a maximum of 35 days in between doses at all visits except the SFU Visit. The SFU Visit window is -3 to +7 days 
from last dose. 
 
Has been changed to:  
a Visit windows are ±7 days from the scheduled visit day (relative to the first dose) with a minimum of 21 days and 
a maximum of 35 days in between doses at all visits except the SFU Visit. For the SFU Visit, the visit should 
occur no more than window is 3 days prior to the scheduled visit date and within 7 days after the scheduled 
visit date (-3 days/ to +7 days) from last dose. 
 
Change #11 
Table 5-1: Schedule of study assessments (footnote i) 
i If the BSA affected by PSO was ≥3% at this visit, determine the PASI. 
 
Has been changed to:  
i If the BSA affected by PSO was ≥3% at this visit Baseline of PA0008, determine the PASI. 
 
Change #12 
Section 6.1 Inclusion criteria, #1 and #2 
1. An Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved written 
Informed Consent form is signed and dated by the subject or legal representative.  
2. Subject or legal representative is considered reliable and capable of adhering to the protocol 
(eg, able to understand and complete questionnaires), visit schedule, or medication intake 
according to the judgment of the Investigator. 
Has been changed to: 
1a. An Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved written 
Informed Consent form is signed and dated by the subject or legal representative.  
2a. Subject or legal representative is considered reliable and capable of adhering to the protocol 
(eg, able to understand and complete questionnaires), visit schedule, or medication intake 
according to the judgment of the Investigator. 
 
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Change #13 
Section 6.3.1 Potential drug-induced liver injury investigational medicinal product 
discontinuation criteria, paragraph 2 
The PDILI criteria below require immediate and permanent discontinuation of IMP:   
Has been changed to: 
The PDILI criteria below require immediate and permanent discontinuation of IMP:   
 
Change #14 
Section 7.1 Description of investigational medicinal product 
The IMP will consist of the following: 
Bimekizumab will be supplied as a clear to opalescent, colorless to slightly brown, sterile, 
preservative-free solution in a 
 
 
Has been changed to: 
The IMP will consist of the following: 
 Bimekizumab will be supplied as a clear to opalescent, colorless to slightly brown, 
sterile, preservative-free solution in a 1mL prefilled syringe (PFS). 
 
 
 
 for sc injection. 
 
Change #15 
Section 8.1 Visit 1 
 If the BSA affected by PSO is ≥3%, determine the Psoriasis Area and Severity Index 
(PASI)* 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the Psoriasis Area and 
Severity Index (PASI)* 
 
Change #16 
Section 8.3 Week 12 (Visit 4), Week 24 (Visit 5), Week 36 (Visit 6), and Week 72 (Visit 9) 
 If the BSA affected by PSO is ≥3%, determine the PASI 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
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Change #17 
Section 8.5 Week 48 (Visit 7) and Week 96 (Visit 11) 
 If the BSA affected by PSO is ≥3%, determine the PASI 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 
Change #18 
Section 8.6 Week 60 (Visit 8) and Week 84 (Visit 10) 
 If the BSA affected by PSO is ≥3%, determine the PASI 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 
Change #19 
Section 8.7 Week 100 (Visit 12) 
 If the BSA affected by PSO is ≥3%, determine the PASI 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 
Change #20 
Section 8.8 Week 104 (Visit 13) or Early Termination Visit 
 If the BSA affected by PSO is ≥3%, determine the PASI 
Has been changed to: 
 If the BSA affected by PSO is ≥3% at Baseline of PA0008, determine the PASI 
 
Change #21 
Section 9.1.3 AEs for special monitoring 
UCB has identified AEs for special monitoring (AESM). An AESM is an AE or safety topic for 
which special monitoring, additional data collection activities, and/or enhanced signal detection 
activities (within UCB), are considered appropriate. Identified AESM can be of particular 
concern based on findings from the IMP clinical program to date, potential risks generally 
associated with biologic immunomodulators, or comorbidities and risk factors prevalent in the 
study population. 
Adverse events for special monitoring for this study include: serious infections (including 
opportunistic infections and TB, see Section 9.6.5), cytopenias, hypersensitivities, suicide 
ideation or behavior (assessed using the eC-SSRS), depression and anxiety (assessed using the 
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HADS, see Section 10.15), major cardiovascular events and liver function test changes/enzyme 
elevations (ALT, AST, and bilirubin; see Section 9.1.5), malignancies, and inflammatory bowel 
diseases.  
Has been changed to: 
Section 9.1.3 AEs for special monitoring Other safety topics of interest 
UCB has identified AEs for special monitoring (AESM). An AESM is an AE or Pre-specified 
safety topics of interest for which special monitoring, additional data collection activities, and/or 
enhanced signal detection activities (within UCB), are considered appropriate. Identified AESM 
can be of particular concern the study are: infections (serious, opportunistic, fungal ,and TB), 
neutropenia, hypersensitivity, suicidal ideation and behavior, depression, major 
cardiovascular events, liver function test changes/enzyme elevations, malignancies, and 
inflammatory bowel diseases (with gastroenterology referral, as appropriate). This is based 
on findings from the IMP clinical program to date, potential risks generally associated with 
biologic immunomodulators, or comorbidities and risk factors prevalent in the study population 
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. 
Adverse events for special monitoring for this study include: serious infections (including 
opportunistic infections and TB, see Section 9.6.5), cytopenias, hypersensitivities, suicide 
ideation or behavior (assessed using the eC-SSRS), depression and anxiety (assessed using the 
HADS, see Section 10.15), major cardiovascular events and liver function test changes/enzyme 
elevations (ALT, AST, and bilirubin; see Section 9.1.5), malignancies, and inflammatory bowel 
diseases.  
Change #22 
Section 9.1.6 Follow-up of AEs, first paragraph 
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 subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and AESMs; further details regarding 
follow-up of PDILI events are provided in Section 9.5.1.5. Information on SAEs obtained after 
clinical database lock will be captured through the Patient Safety (PS) database without 
limitation of time. 
Has been changed to: 
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 subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and other safety topics of interestAESMs; 
further details regarding follow-up of PDILI events are provided in Section 9.5.1.5. Information 
on SAEs obtained after clinical database lock will be captured through the Patient Safety (PS) 
database without limitation of time. 
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Change #23 
Section 9.2.3 Follow-up of SAEs 
An SAE should be followed until it has resolved, has a stable sequelae, the Investigator 
determines that it is no longer clinically significant, or the subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and AESMs; further details regarding 
follow-up of PDILI events are provided in Section 9.5.1.5. Information on SAEs obtained after 
clinical database lock will be captured through the PS database without limitation of time. 
Has been changed to: 
An SAE should be followed until it has resolved, has a stable sequelae, the Investigator 
determines that it is no longer clinically significant, or the subject is lost to follow-up. This 
follow-up requirement applies to AEs, SAEs, AESIs, and AESMsother safety topics of interest; 
further details regarding follow-up of PDILI events are provided in Section 9.5.1.5. Information 
on SAEs obtained after clinical database lock will be captured through the PS database without 
limitation of time. 
 
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Change #24 
Table 9-3: 
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 
≥3xULN 
≥2xULNb 
NA 
 
 
Hepatology consult.c 
Medical Monitor must be 
notified within 24 hours 
(eg, by laboratory alert) 
and subject discussed with 
Medical Monitor ASAP. 
Immediate, permanent 
IMP discontinuation. 
 
Essential: Must have 
repeat liver chemistry 
values and additional 
testing completed 
ASAP (see 
Section 9.5.1.4); 
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.d 
 
 
 
 
 
 
 
 
 
≥3xULN 
NA 
Yes 
≥5xULN 
NA 
NA 
Need for hepatology 
consult to be discussed.     
(required if ALT or AST 
≥8xULN) Medical 
Monitor must be notified 
within 24hours (eg, by 
laboratory alert) and 
subject discussed with 
Medical Monitor ASAP. 
Immediate, permanent 
IMP discontinuation 
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PA0009 
 
 
 
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Table 9-3: 
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 
≥3xULN 
(and ≥2x 
baseline) and 
<5xULN 
(and ≥2x 
baseline) 
<2xULN 
No 
Discussion with Medical 
Monitor required. 
Consider need for 
hepatology consult if there 
is no evidence of 
resolution (see Follow-up 
requirements) c 
Further investigation – 
immediate IMP 
discontinuation not 
required (see 
Section 9.5.1.2). 
IMP discontinuation 
required if any of the 
following occur: 
 Subject cannot comply 
with monitoring 
schedule.  
 
Liver chemistry 
values continue to 
increase  
 
Liver chemistry 
values remain 
≥3xULN (and 
≥2xbaseline) after 2 
weeks of monitoring 
without evidence of 
resolution  
Essential: Every 
attempt must be 
made to have repeat 
liver chemistry 
values and additional 
testing completed 
within 48hours at the 
site with HCP (see 
Section 9.5.1.4). 
Monitoring of liver chemistry values at 
least twice per week for 2 weeks.d 
 
Immediate IMP discontinuation 
required if liver chemistry values 
continue to increase.  
After 2 weeks of monitoring liver 
chemistry values:  
 
Discontinue IMP if levels remain 
≥3xULN (and ≥2x baseline) 
without evidence of resolutiond  
Continue to monitor until values 
normalize, stabilize, or return to within 
baseline valuesd. 
 
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PA0009 
 
 
 
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Has been changed to:  
Table 9-3: 
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 
≥3xULN 
≥2xULNb 
NA 
 
 
Hepatology consult.c 
Medical Monitor must be 
notified within 24 hours 
(eg, by laboratory alert) 
and subject discussed with 
Medical Monitor ASAP. 
Immediate, permanent 
IMP discontinuation. 
 
Essential: Must have 
repeat liver chemistry 
values and additional 
testing completed 
ASAP (see 
Section 9.5.1.4); 
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.d 
 
 
 
 
 
 
 
 
 
≥3xULN 
NA 
Yes 
≥5xULN 
NA 
NA 
Need for hepatology 
consult to be discussed.     
(required if ALT or AST 
≥8xULN) Medical 
Monitor must be notified 
within 24hours (eg, by 
laboratory alert) and 
subject discussed with 
Medical Monitor ASAP. 
Immediate, permanent 
IMP discontinuation 
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PA0009 
 
 
 
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Table 9-3: 
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 
≥3xULN 
(and ≥2x 
baseline) and 
<5xULN 
(and ≥2x 
baseline) 
<2xULN 
No 
Discussion with Medical 
Monitor required. 
Consider need for 
hepatology consult if there 
is no evidence of 
resolution (see Follow-up 
requirements) c 
Further investigation – 
immediate IMP 
discontinuation not 
required (see 
Section 9.5.1.2). 
IMP discontinuation 
required if any of the 
following occur: 
 Subject cannot comply 
with monitoring 
schedule.  
 
Liver chemistry 
values continue to 
increase  
 
Liver chemistry 
values remain 
≥3xULN (and 
≥2xbaseline) after 2 
weeks of monitoring 
without evidence of 
resolution  
Essential: Every 
attempt must be 
made to have repeat 
liver chemistry 
values and additional 
testing completed 
within 48hours at the 
site with HCP (see 
Section 9.5.1.4). 
Monitoring of liver chemistry values at 
least twice per week for 2 weeks.d 
 
Immediate IMP discontinuation 
required if liver chemistry values 
continue to increase.  
After 2 weeks of monitoring liver 
chemistry values:  
 
Discontinue IMP if levels remain 
≥3xULN (and ≥2x baseline) 
without evidence of resolutiond  
Continue to monitor until values 
normalize, stabilize, or return to within 
Baseline valuesd. 
 
 
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Change #25 
Section 9.5.1.2 Immediate action: determination of IMP discontinuation, paragraph 2 
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 6.3.1 and Table 9-3 for details). 
Has been changed to: 
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 6.3.1 and Table 9-3 for details). 
 
Change #26 
Section 10.8 ACR20, ACR50, and ACR70 response, paragraph 1 
The ACR20, ACR50, and ACR70 response rates are based on a 20%, 50%, and 70% or greater 
improvement relative to Baseline of PA0008 and PA0009 entry values in the following 
measures: 
Has been changed to: 
The ACR20, ACR50, and ACR70 response rates are based on a 20%, 50%, and 70% or greater 
improvement relative to Baseline of PA0008 and PA0009 entry values in the following 
measures: 
 
Change #27 
Section 10.10 Psoriasis Area and Severity Index (PASI), paragraph 1 
Psoriasis Area and Severity Index will be assessed in all subjects with study entry BSA affected 
by PSO ≥3% determined by the method described in Section 10.9 (ie, the BSA palm method).  
Has been changed to: 
Psoriasis Area and Severity Index will be assessed in all subjects with study entry BSA affected 
by PSO ≥3% at Baseline of PA0008 determined by the method described in Section 10.9 (ie, the 
BSA palm method).  
 
Change #28 
Section 10.10 Psoriasis Area and Severity Index (PASI), last paragraph 
The PASI75, PASI90, and PASI100 responses are based on at least 75%, 90%, and 100% 
improvement in the PASI score compared to Baseline in PA0008 and PA0009 entry values. 
Thereafter PASI will be assessed for the purposes of determining response only in subjects with 
PSO involving at least 3% of BSA at study entry.  
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Bimekizumab 
PA0009 
 
 
 
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Page 112 of 116 
Has been changed to: 
The PASI75, PASI90, and PASI100 responses are based on at least 75%, 90%, and 100% 
improvement in the PASI score compared to Baseline in PA0008 and PA0009 entry values. 
Thereafter PASI will be assessed analyzed for the purposes of determining response only in 
subjects with PSO involving at least 3% of BSA at study entry Baseline of PA0008.  
 
Change #29 
Section 13.1 Definition of analysis sets, last paragraph 
The Full Analysis Set (FAS) will consist of all enrolled subjects who receive at least 1 dose of 
the IMP and have a valid measurement for at least 1 efficacy variable at PA0009 study entry.  
Has been changed to: 
The Full Analysis Set (FAS) will consist of all enrolled subjects who receive at least 1 dose of 
the IMP and have a valid measurement for at least 1 efficacy variable at after PA0009 study 
entry visit.  
 
Change #30 
Section 13.3.1 Safety analyses, last 2 paragraphs  
Change from PA0009 entry values in laboratory and vital signs variables will be summarized 
descriptively by visit and by treatment group at completion of PA0008. 
All safety analyses will be conducted for both subpopulations. 
Has been changed to: 
Change from PA0009 entry PA0008 Baseline values in laboratory and vital signs variables will 
be summarized descriptively by visit and by treatment group at completion of PA0008. Change 
from PA0009 Laboratory Baseline values in clinical laboratory variables (hematology and 
biochemistry, excepting high-sensitivity CRP) will be summarized descriptively by visit and 
by treatment group at completion of PA0008. 
Due to a change in laboratory vendor between PA0008 and PA0009, laboratory values 
(excepting CRP) will use the PA0009 Laboratory Baseline, defined as the earliest post-
entry visit value recorded in PA0009. Change from PA0009 Laboratory Baseline will be 
calculated for these parameters. (The CRP values from the 2 analyzing laboratories have 
been calibrated, so change from PA0008 Baseline will be calculated for that parameter.) 
All safety analyses will be conducted for both subpopulations. 
 
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Change #31 
Section 13.4 Planned efficacy analyses, paragraphs 2 and 3 
Responder variables (eg, ACR20 response) will be derived relative to the Baseline and PA0009 
entry values, and summarized descriptively. Percentages will be summarized descriptively by 
visit, by randomized treatment group, and by treatment group at PA0009 entry. 
Change from Baseline or PA0009 entry values of all continuous variables will be summarized 
descriptively by visit, by randomized treatment group, and by treatment group at completion of 
PA0008. 
Has been changed to: 
Responder variables (eg, ACR20 response) will be derived relative to the Baseline of PA0008 
and PA0009 entry values, and summarized descriptively. Percentages will be summarized 
descriptively by visit, by randomized treatment group, and by treatment group at PA0009 entry. 
Change from Baseline of PA0008 or PA0009 entry values of all continuous variables will be 
summarized descriptively by visit, by randomized treatment group, and by treatment group at 
completion of PA0008. 
 
Change #32 
Section 13.4.1 Subgroup analysis, last bullet 
 Concomitant DMARD status at PA0009 entry 
Has been changed to: 
 Concomitant DMARD status at Baseline of PA0008 PA0009 entry 
 
Change #33 
Section 13.8 Handling of dropouts or missing data 
The following paragraph was added to the end of this section: 
As a sensitivity analysis, the ACR, PASI, LDI, MASES, and MDA efficacy variables will be 
analyzed based on observed data in addition to a sensitivity analysis based on multiple 
imputation of ACR component scores and PASI scores for the ACR and PASI response 
variables, respectively. Subjects with missing data or who have prematurely finished the 
study will be treated as missing. 
 
Change #34 
Section 13.9 Planned interim analysis and data monitoring 
No formal interim analysis is planned for this study. 
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Has been changed to: 
No formal interim analysis is planned for this study. Additional data cuts may be prepared 
following regulatory requests or for publication purposes. 
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18 
DECLARATION AND SIGNATURE OF INVESTIGATOR 
I confirm that I have carefully read and understood this protocol and agree to conduct this 
clinical study as outlined in this protocol, according to current Good Clinical Practice and local 
laws and requirements. 
I will ensure that all subinvestigators and other staff members read and understand all aspects of 
this protocol. 
I have received and read all study-related information provided to me. 
The objectives and content of this protocol as well as the results deriving from it will be treated 
confidentially and will not be made available to third parties without prior authorization by UCB. 
All rights of publication of the results reside with UCB, unless other agreements were made in a 
separate contract. 
Investigator: 
 
 
 
 
Printed name 
 
Date/Signature 
 
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19 
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 and according to current Good Clinical Practice. 
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Approval Signatures
Name:
pa0009-protocol-amend-3
Version:
1. 0
Document Number:
CLIN-000143809
Title:
PA0009 Protocol Amendment 3
Approved Date:
13 Dec 2019
Document Approvals
Approval
Verdict: Approved
Name: 
Capacity: Medical
Date of Signature: 12-Dec-2019 15:54:05 GMT+0000
Approval
Verdict: Approved
Name: 
Capacity: Subject Matter Expert
Date of Signature: 12-Dec-2019 16:46:36 GMT+0000
Approval
Verdict: Approved
Name: 
Capacity: Clinical
Date of Signature: 13-Dec-2019 08:05:13 GMT+0000
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