A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, Parallel-Group Study to Investigate the Efficacy and Safety of Efgartigimod PH20 SC in Adult Participants With Bullous Pemphigoid
Phase: PHASE2
Conditions: Bullous Pemphigoid
Sponsor: argenx

 
 
 
argenx 
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1 
Clinical Study Protocol 
Protocol Title: 
A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, 
Parallel-Group Study to Investigate the Efficacy and Safety 
of Efgartigimod PH20 SC in Adult Participants With Bullous 
Pemphigoid 
Protocol Number: 
ARGX-113-2009 
Version Number: 
4.0 (Amendment 3) 
Compound: 
Efgartigimod (ARGX-113) 
Brief Title: 
A phase 2/3 study of efgartigimod PH20 SC in adult participants 
with bullous pemphigoid 
Study Phase: 
2/3 
Acronym: 
BALLAD 
Sponsor Name: 
argenx BV 
Legal Registered  
Address: 
Industriepark Zwijnaarde 7 
9052 Zwijnaarde (Ghent) 
Belgium 
Phone: +32 9 310 34 00  
Fax: +32 9 310 34 99 
Regulatory Agency 
Identifier Number(s): 
IND: 
 
EU CT: 2023-508645-40 
Approval Date: 
27 Feb 2024 
 
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Clinical Study Protocol ARGX-113-2009 (BALLAD) v4.0 
27 Feb 2024 
Efgartigimod PH20 SC—BP 
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Sponsor’s Medical 
Contact: 
, MD, PhD 
Senior Medical Director, Clinical Development  
argenx BV  
Industriepark Zwijnaarde 7  
9052 Zwijnaarde (Ghent)  
Belgium  
Office Phone: 
  
Email:
 
Contract Research 
Organization: 
(Globally except for 
China) 
Pharmaceutical Product Development (PPD) Global Ltd  
Granta Park, Great Abington  
Cambridge, CB21 6GQ, United Kingdom  
Phone: +44 1223 374100 
Sponsor’s Designee 
(China only): 
Zai Lab (Shanghai) 
4/F, No. 1 South Tower 
4560 Jinke Rd. 
Pilot Free Trade Zone (Shanghai) 
P.R. China 
24-Hour Urgent 
Medical Helpline:  
Europe/Asia-Pacific: +44 1223 374240 
North America: +1 800 201 8725 
Serious Adverse 
Event Reporting: 
Email: safety@argenx.com 
Fax: +1 833 874 7325  
 
 
 
 
 
 
 
 
Confidentiality Statement 
The information contained in this medium is the property of argenx BV and/or its subsidiaries 
(jointly “argenx”) and is confidential and proprietary. Without prior authorization from 
argenx, information contained herein may not be used, reproduced, divulged, published, 
or otherwise disclosed to anyone. 
 
 
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Clinical Study Protocol ARGX-113-2009 (BALLAD) v4.0 
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SIGNATURE OF THE SPONSOR 
Protocol Title: 
A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, 
Parallel-Group Study to Investigate the Efficacy and Safety 
of Efgartigimod PH20 SC in Adult Participants With Bullous 
Pemphigoid 
Protocol Number: 
ARGX-113-2009 
Acronym: 
BALLAD 
Sponsor Signatory: 
 
 
 
See appended signature page 
 
 
, MD, PhD 
Chief Medical Officer 
 
 
Date  
 
 
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Clinical Study Protocol ARGX-113-2009 (BALLAD) v4.0 
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SIGNATURE OF THE INVESTIGATOR 
Investigator’s Acknowledgment 
I have read this protocol for study ARGX-113-2009. 
Title: A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, Parallel-Group Study to 
Investigate the Efficacy and Safety of Efgartigimod PH20 SC in Adult Participants With Bullous 
Pemphigoid 
I have fully discussed the objective(s) of this study and the contents of this protocol with the 
sponsor’s representative. 
I understand that the information in this protocol is confidential and should not be disclosed, other 
than to those directly involved in the execution or the scientific/ethical review of the study, without 
written authorization from the sponsor. It is, however, permissible to provide the information 
contained herein to a participant to obtain their consent to participate. 
I agree to conduct this study according to this protocol and to comply with its requirements, subject 
to ethical and safety considerations and guidelines, and to conduct the study in accordance with 
International Council for Harmonisation of Technical Requirements for Registration of 
Pharmaceuticals for Human Use guidelines on Good Clinical Practice and with the applicable 
regulatory requirements. 
I understand that failure to comply with the requirements of the protocol may lead to the termination 
of my participation as an investigator for this study. 
I understand that the sponsor may decide to suspend or prematurely terminate the study at any time 
for whatever reason; such a decision will be communicated to me in writing. Conversely, should I 
decide to withdraw from execution of the study, I will communicate my intention immediately in 
writing to the sponsor. 
 
 
 
Investigator Name,  
Institution, 
and Address: 
(please hand print or type) 
 
 
 
 
Signature: 
 
 
 
Date: 
 
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PROTOCOL AMENDMENT SUMMARY OF CHANGES 
Global protocol document history 
Date 
Amendment 3 v4.0 
27 Feb 2024 
Amendment 2 v3.0 
27 Mar 2023 
Amendment 1 v2.0 
10 May 2022 
Original v1.0 
10 Dec 2021 
Amendment 3 (27 Feb 2024) 
This amendment is considered substantial based on the definition in Article 2 §2 (13) of the 
Regulation (EU) No 536/2014 of the European Parliament and the Council of the European Union. 
Overall Rationale for This Amendment 
The primary rationale for this amendment is to comply with Clinical Trial Regulations. 
The major changes from protocol version 3.0 to protocol version 4.0 are summarized in the 
following table. Minor editorial changes, including the correction of typographical errors and 
formatting inconsistencies, are not summarized. Refer to the Abbreviations and Definitions for any 
undefined terms or abbreviations. 
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Section 
Change in study operation or 
planned analysis 
Brief rationale 
1.1. Synopsis 
Synopsis has been shortened and 
restructured. 
To comply with Clinical Trial 
Regulations 
2.3.2. Benefit Assessment 
Anticipated benefit based on results 
from the pemphigus phase 2 study 
(ARGX-113-1701) was removed. 
To reflect the results of the 
pemphigus phase 3 study 
(ARGX-113-1904), which did not 
meet its primary and secondary 
efficacy endpoints 
9.3.3.5. Other Analyses 
Pooled analyses of parts A and B 
were added. 
To explore the effect of 
efgartigimod across parts A and B 
7.2. Participant 
Discontinuation/Withdrawal 
From the Study 
Revised text (deleted text is shown 
in strikethrough font; new text is 
shown in bold font): 
If the participant also withdraws 
consent to disclose future 
information, the sponsor may retain 
and continue to use any data 
collected before such a withdrawal 
of consent. 
The samples from participants 
withdrawing from the study that 
have already been collected (but 
may not have been analyzed) 
before withdrawal will still be used 
for the study but not for future 
research. 
If the participant withdraws 
consent to participate in the 
study, the sponsor can retain and 
continue to use any data collected 
before consent was withdrawn. 
Future research on samples 
collected from participants who 
withdraw consent to participate 
in the study will not be affected 
unless the participant also 
withdraws the consent for future 
research. 
To clarify guidance on future 
sample use 
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Section 
Change in study operation or 
planned analysis 
Brief rationale 
5.2. Exclusion Criteria 
2.3.1., Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009 
8.3.7. Infections and 
Vaccinations 
8.4.7.1. Risk Mitigation for 
COVID-19 and Other 
Significant Infections 
Exclusion criterion “5B. Active, 
chronic, or latent infection at 
screening” has been revised and 
renumbered to “5C. Clinically 
significant active infection that is 
not sufficiently resolved before 
baseline in the investigator’s 
opinion.” 
To align with the current 
efgartigimod IB 
1.3. Schedule of Activities 
(SoA) 
2.3. Benefit/Risk Assessment 
6.4. Study Compliance 
Participants no longer need to be 
monitored for at least 30 minutes 
after IMP administration. 
8.3.8. Pregnancy Testing 
Participants or their partners who 
become pregnant during the study 
will be asked to consent to be 
followed for up to 12 months after 
the baby’s birth. 
To ensure follow-up on the 
baby’s health 
1.3. Schedule of Activities (SoA) 
The SoA was simplified: 
• Cross-references to applicable 
protocol sections were listed in a 
new column 
• Information on treatment period, 
mandatory visits, and other 
weekly visits included in footnote 
b was split into 3 footnotes 
• Nonessential footnotes were 
removed. 
To ensure protocol compliance  
6.3. Measures to Minimize 
Bias: Randomization and 
Blinding 
Correction was implemented: The 
site enrolls the participants and 
assigns them a unique participant 
ID at the first screening visit, and 
not upon signing informed consent. 
8.1.5. Unscheduled Visits 
1.3. Schedule of Activities 
(SoA) – footnote h 
Clarification was added that in case 
of relapse, IGA-BP, BPDAI, and 
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Section 
Change in study operation or 
planned analysis 
Brief rationale 
Itch NRS assessments must be 
performed. 
6.8.1.3. Oral Prednisone Dose 
Adjustment Regimen (Based on 
BP Disease Assessment) 
Clarification was added that OCS 
tapering will be delayed if a 
participant has new lesions after the 
start of OCS tapering. 
8.5. Pharmacokinetics 
Clarification was added that blood 
samples for PK analysis can be 
collected at any time if no IMP is 
administered. 
 
 
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TABLE OF CONTENTS 
SIGNATURE OF THE SPONSOR .................................................................................................3 
SIGNATURE OF THE INVESTIGATOR ......................................................................................4 
PROTOCOL AMENDMENT SUMMARY OF CHANGES ..........................................................5 
LIST OF TABLES .........................................................................................................................15 
LIST OF FIGURES .......................................................................................................................15 
ABBREVIATIONS AND DEFINITIONS ....................................................................................16 
1. 
PROTOCOL SUMMARY ..........................................................................................20 
1.1. 
Synopsis ......................................................................................................................20 
1.2. 
Schema ........................................................................................................................22 
1.3. 
Schedule of Activities (SoA) ......................................................................................24 
2. 
INTRODUCTION ......................................................................................................29 
2.1. 
Study Rationale ...........................................................................................................29 
2.2. 
Background .................................................................................................................30 
2.3. 
Benefit/Risk Assessment ............................................................................................31 
2.3.1. 
Risk Assessment .........................................................................................................31 
2.3.2. 
Benefit Assessment .....................................................................................................33 
2.3.3. 
Overall Benefit-Risk Conclusion ................................................................................34 
3. 
OBJECTIVES, ENDPOINTS, AND ESTIMANDS ..................................................35 
3.1. 
Objectives and Endpoints for Part A of ARGX-113-2009 
(Phase 2 Proof-of-Concept Part of Study) ..................................................................35 
3.2. 
Objectives and Endpoints for Part B of ARGX-113-2009 (Phase 3 Confirmatory 
Part of Study) ..............................................................................................................37 
4. 
STUDY DESIGN .......................................................................................................41 
4.1. 
Overall Design ............................................................................................................41 
4.1.1. 
Description of Part A and Part B ................................................................................41 
4.1.2. 
Conduct of Both Parts A and B ..................................................................................41 
4.1.3. 
Bullous Pemphigoid Disease Status Terminology to Be Used in the Study ..............44 
4.2. 
Scientific Rationale for Study Design ........................................................................44 
4.2.1. 
Rationale for Selection of a Phase 2/3 Study ..............................................................44 
4.2.2. 
Rationale for the Selection of the Participant Population ...........................................45 
4.2.3. 
Rationale for the Selection of the Oral Corticosteroid Dosing Regimen ...................46 
4.2.4. 
Rationale for the Selection of Study Endpoints ..........................................................46 
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4.2.4.1. 
Primary Endpoint ........................................................................................................46 
4.2.4.2. 
Secondary Efficacy Endpoints ....................................................................................47 
4.2.4.3. 
Safety Endpoints .........................................................................................................48 
4.2.4.4. 
Pharmacokinetics, Pharmacodynamics, and Immunogenicity Endpoints ..................48 
4.2.5. 
Rationale for the Selection of Study Assessments .....................................................48 
4.3. 
Justification for Selection of the Treatment Regimen and Dose ................................49 
4.4. 
End of Study Definition ..............................................................................................50 
5. 
STUDY POPULATION .............................................................................................51 
5.1. 
Inclusion Criteria ........................................................................................................51 
5.2. 
Exclusion Criteria .......................................................................................................51 
5.3. 
Lifestyle Considerations .............................................................................................53 
5.4. 
Screen Failures ............................................................................................................53 
5.5. 
Criteria for Temporarily Delaying Study Participation ..............................................53 
6. 
IMP(S) AND CONCOMITANT THERAPY .............................................................55 
6.1. 
IMP(s) Administered ..................................................................................................55 
6.2. 
Preparation, Handling, Storage, and Accountability ..................................................57 
6.2.1. 
Preparation ..................................................................................................................57 
6.2.2. 
Handling .....................................................................................................................58 
6.2.3. 
Storage ........................................................................................................................58 
6.2.4. 
Accountability .............................................................................................................59 
6.2.5. 
Packaging and Labeling ..............................................................................................59 
6.3. 
Measures to Minimize Bias: Randomization and Blinding ........................................59 
6.3.1. 
Emergency Unblinding ...............................................................................................59 
6.4. 
Study Compliance .......................................................................................................60 
6.4.1. 
Handling Missed Doses of the IMP ............................................................................61 
6.4.2. 
Protocol Deviations ....................................................................................................61 
6.5. 
Dose Modification ......................................................................................................61 
6.6. 
Continued Access to IMP After the End of the Study ................................................61 
6.7. 
Treatment of Overdose ...............................................................................................62 
6.8. 
Concomitant Therapy .................................................................................................62 
6.8.1. 
Concurrent Bullous Pemphigoid Therapy – Oral Prednisone ....................................62 
6.8.1.1. 
General Oral Prednisone Information .........................................................................63 
6.8.1.2. 
Oral Prednisone Dosing and Treatment Compliance .................................................63 
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6.8.1.3. 
Oral Prednisone Dose Adjustment Regimen (Based on BP Disease Assessment) ....63 
6.8.2. 
Prohibited Medications and Therapy During the Study .............................................67 
6.8.3. 
Rescue Therapy ..........................................................................................................67 
7. 
IMP DISCONTINUATION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL ..................................................................68 
7.1. 
IMP Discontinuation ...................................................................................................68 
7.1.1. 
Permanent Discontinuation .........................................................................................68 
7.1.2. 
Temporary Discontinuation ........................................................................................69 
7.2. 
Participant Discontinuation/Withdrawal From the Study ...........................................70 
7.3. 
Lost to Follow-up .......................................................................................................70 
8. 
STUDY ASSESSMENTS AND PROCEDURES ......................................................72 
8.1. 
General Considerations ...............................................................................................72 
8.1.1. 
General ........................................................................................................................72 
8.1.2. 
Screening Period .........................................................................................................72 
8.1.3. 
Treatment and Follow-Up Periods ..............................................................................73 
8.1.4. 
Home Study Visits ......................................................................................................73 
8.1.5. 
Unscheduled Visits .....................................................................................................73 
8.2. 
Efficacy and Quality of Life Assessments ..................................................................74 
8.2.1. 
Efficacy Assessments .................................................................................................74 
8.2.1.1. 
Assessment of BP Disease Status and OCS Dose Monitoring ...................................74 
8.2.1.2. 
Investigator Global Assessment of Bullous Pemphigoid ...........................................74 
8.2.1.3. 
Bullous Pemphigoid Disease Area Index ...................................................................74 
8.2.1.4. 
Itch Numerical Rating Scale .......................................................................................74 
8.2.2. 
Quality of Life (QoL) Assessments ............................................................................74 
8.3. 
Safety Assessments .....................................................................................................75 
8.3.1. 
Physical Examinations ................................................................................................75 
8.3.2. 
Height and Weight ......................................................................................................75 
8.3.3. 
Vital Signs ..................................................................................................................75 
8.3.4. 
Electrocardiograms .....................................................................................................76 
8.3.5. 
Medical and Surgical History .....................................................................................76 
8.3.6. 
Clinical Safety Laboratory Tests ................................................................................76 
8.3.6.1. 
Standard Blood and Urine Laboratory Tests ..............................................................76 
8.3.6.2. 
Substudy (at Selected Sites) – Vaccination Response ................................................77 
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8.3.6.3. 
Use and Storage of Blood Samples ............................................................................77 
8.3.7. 
Infections and Vaccinations ........................................................................................78 
8.3.8. 
Pregnancy Testing ......................................................................................................79 
8.3.9. 
Additional Safety Assessment – the Glucocorticoid Toxicity Index..........................79 
8.4. 
Adverse Events, Serious Adverse Events, and Other Safety Reporting .....................80 
8.4.1. 
Time Period and Frequency for Collecting Information on AEs, SAEs, 
and AESIs ...................................................................................................................80 
8.4.2. 
Method of Detecting AEs and SAEs ..........................................................................80 
8.4.3. 
Follow-up of AEs and SAEs .......................................................................................81 
8.4.4. 
Reporting of AEs and SAEs .......................................................................................81 
8.4.5. 
Regulatory Reporting Requirements for SAEs ...........................................................82 
8.4.6. 
Pregnancy ...................................................................................................................82 
8.4.7. 
Adverse Events of Special Interest .............................................................................83 
8.4.7.1. 
Risk Mitigation for COVID-19 and Other Significant Infections ..............................83 
8.4.8. 
AEs of Clinical Interest ..............................................................................................83 
8.4.8.1. 
Infusion/Injection-Related Reactions .........................................................................83 
8.4.8.2. 
Injection Site Reactions ..............................................................................................84 
8.5. 
Pharmacokinetics ........................................................................................................84 
8.6. 
Pharmacodynamics .....................................................................................................84 
8.7. 
Genetics ......................................................................................................................85 
8.8. 
Biomarkers ..................................................................................................................85 
8.9. 
Immunogenicity Assessments ....................................................................................85 
8.10. 
Imaging Substudy .......................................................................................................85 
8.11. 
Health Economics OR Medical Resource Utilization and Health Economics ...........85 
9. 
STATISTICAL CONSIDERATIONS .......................................................................86 
9.1. 
Statistical Hypotheses .................................................................................................86 
9.1.1. 
Multiplicity Adjustment..............................................................................................87 
9.2. 
Analysis Sets ...............................................................................................................87 
9.3. 
Statistical Analyses .....................................................................................................87 
9.3.1. 
General Considerations ...............................................................................................87 
9.3.2. 
Primary Endpoint/Estimand Analysis .........................................................................88 
9.3.3. 
Secondary Endpoints Analysis ...................................................................................89 
9.3.3.1. 
Analysis of Secondary Efficacy Endpoints (Part B Only) ..........................................89 
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9.3.3.2. 
Analysis of Other Secondary Endpoints .....................................................................90 
9.3.3.3. 
Safety Analyses ..........................................................................................................91 
9.3.3.4. 
Exploratory Endpoint Analysis...................................................................................91 
9.3.3.5. 
Other Analyses ............................................................................................................91 
9.4. 
Interim Analysis (Part A) ............................................................................................91 
9.4.1. 
Futility Analysis..........................................................................................................92 
9.5. 
Sample Size Determination ........................................................................................94 
10. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS ..................................................................................................96 
10.1. 
Appendix 1: Regulatory, Ethical, and Study Oversight Considerations ....................96 
10.1.1. 
Regulatory and Ethical Considerations ......................................................................96 
10.1.2. 
Financial Disclosure ...................................................................................................96 
10.1.3. 
Informed Consent Process ..........................................................................................97 
10.1.4. 
Data Protection ...........................................................................................................97 
10.1.5. 
Data and Safety Monitoring Board .............................................................................98 
10.1.6. 
Dissemination of Clinical Study Data ........................................................................98 
10.1.7. 
Data Quality Assurance ..............................................................................................98 
10.1.7.1. 
Data Handling and Record Keeping ...........................................................................99 
10.1.7.2. 
Quality Assurance Audit .............................................................................................99 
10.1.7.3. 
Quality Control .........................................................................................................100 
10.1.8. 
Source Documents ....................................................................................................100 
10.1.9. 
Monitoring ................................................................................................................101 
10.1.10. 
Data Management .....................................................................................................101 
10.1.11. 
Study and Site Start and Closure ..............................................................................102 
10.1.11.1. General Considerations .............................................................................................102 
10.1.11.2. Site Closure ...............................................................................................................103 
10.1.11.3. Study Closure............................................................................................................103 
10.1.12. 
Investigator Obligations ............................................................................................103 
10.1.13. 
Protocol Signatures ...................................................................................................104 
10.1.14. 
Publication Policy .....................................................................................................104 
10.2. 
Appendix 2: Clinical Laboratory Tests .....................................................................106 
10.2.1. 
Other Screening Tests ...............................................................................................107 
10.2.1.1. 
COVID-19 ................................................................................................................107 
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10.2.1.2. 
QuantiFERON-TB, IGRA Test & Testing for Active Tuberculosis Infection .........107 
10.2.1.3. 
Hepatitis B Virus ......................................................................................................107 
10.2.1.4. 
Hepatitis C Virus ......................................................................................................108 
10.2.1.5. 
Human Immunodeficiency Virus .............................................................................108 
10.3. 
Appendix 3: AEs and SAEs: Definitions and Procedures for Recording, 
Evaluating, Follow-up, and Reporting ......................................................................109 
10.3.1. 
Definition of AE .......................................................................................................109 
10.3.2. 
Definition of SAE .....................................................................................................110 
10.3.3. 
Recording and Follow-Up of AE and/or SAE ..........................................................110 
10.3.4. 
Reporting of SAEs and AESIs ..................................................................................112 
10.4. 
Appendix 4: Contraceptive and Barrier Guidance ....................................................113 
10.4.1. 
Women of Childbearing Potential Definition ...........................................................113 
10.4.2. 
Contraception Guidance ...........................................................................................113 
10.4.2.1. 
Female Contraception for Women of Childbearing Potential ..................................113 
10.4.2.2. 
Male Contraception ..................................................................................................114 
10.5. 
Appendix 5: The Karnofsky Performance Index ......................................................115 
10.6. 
Appendix 6: Investigator Global Assessment of Bullous Pemphigoid (IGA-BP) ...116 
10.7. 
Appendix 7: Bullous Pemphigoid Disease Area Index (BPDAI) Questionnaire .....117 
10.8. 
Appendix 8: The Itch Numerical Rating Scale (Itch NRS) ......................................118 
10.9. 
Appendix 9: The EuroQol 5-Dimension 5-Level (EQ-5D-5L) ................................119 
10.10. 
Appendix 10: Dermatology Life Quality Index (DLQI) ..........................................121 
10.11. 
Appendix 11: Autoimmune Bullous Disease Quality of Life (ABQoL) 
Questionnaire ............................................................................................................122 
10.12. 
Appendix 12: The Glucocorticoid Toxicity Index ....................................................125 
10.13. 
Appendix 13: Country-Specific Requirements .........................................................128 
10.13.1. 
Japan .........................................................................................................................128 
10.13.2. 
China .........................................................................................................................128 
10.14. 
Appendix 14: Operational Considerations for COVID-19 Risk Mitigation .............131 
10.14.1. 
Testing for COVID-19 ..............................................................................................131 
10.14.2. 
Study Protocol Changes ............................................................................................131 
10.14.3. 
Mandatory Site Visits ...............................................................................................131 
10.15. 
Appendix 15: Protocol Amendment History ............................................................133 
11. 
REFERENCES .........................................................................................................150 
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LIST OF TABLES 
Table 1: 
Schedule of Activities (SoA) ......................................................................................24 
Table 2: 
Potential Risks and Mitigation Strategies for ARGX-113-2009 ................................32 
Table 3: 
Part A Objectives and Endpoints ................................................................................35 
Table 4: 
Part B Objectives and Endpoints ................................................................................37 
Table 5: 
IMP(s) Administered ..................................................................................................55 
Table 6: 
Study Arm(s) ..............................................................................................................57 
Table 7: 
Concurrent Oral Prednisone Equivalent Doses (in mg) Based on Participant 
Body Weight ...............................................................................................................65 
Table 8: 
Analysis Sets for ARGX-113-2009 ............................................................................87 
Table 9: 
Calculation Matrix Applied to Determine the Appropriate Number 
of Participants in Study ARGX-113-2009 ..................................................................94 
Table 10: Protocol-Required Laboratory Tests.........................................................................106 
Table 11: Interpretation of Hepatitis B Serological Test Results .............................................107 
Table 12: Interpretation of the Hepatitis C Antibody Test .......................................................108 
Table 13: Interpretation of HIV Test Results ...........................................................................108 
Table 14: GTI 2.0 Composite Index (Adapted for ARGX-113-2009) .....................................125 
Table 15: GTI 2.0 Specific List (Adapted for ARGX-113-2009) ............................................126 
Table 16: Concurrent Oral Methylprednisolone Equivalent Doses (in mg) Based on 
Participant Body Weight ...........................................................................................129 
Table 17: Scheme for Study Visits Performed at Home During a COVID-19 Pandemic ........132 
 
LIST OF FIGURES 
Figure 1: 
Operationally Seamless Design of 2-Part Study .........................................................22 
Figure 2: 
Schematic for Both Parts A and B of ARGX-113-2009.............................................23 
Figure 3: 
Probabilities of Producing Favorable (“Go”), Inconclusive (“Consider”), 
and Unfavorable (“Stop”) Outcomes for Part A Futility Analysis With a Sample 
Size of 20 Participants per Study Arm .......................................................................93 
Figure 4: 
Decision Matrix for Favorable (“Go”), Inconclusive (“Consider”), 
and Unfavorable (“Stop”) Outcomes Based on the Absolute Number of 
Responders in Part A Study Arms (Efgartigimod PH20 SC vs Placebo) ...................93 
 
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ABBREVIATIONS AND DEFINITIONS 
Abbreviation/Term 
Expansion/Definition 
ABQoL 
Autoimmune Bullous Disease Quality of Life questionnaire 
ADA 
antidrug antibody(ies) 
ADL 
activities of daily living 
AE 
adverse event 
AESI 
adverse event of special interest 
AIBD 
autoimmune blistering disease 
AIS 
Aggregate Improvement Score (calculated from the C-GTI) 
ALT 
alanine aminotransferase 
ANCOVA 
analysis of covariance 
aPTT 
activated partial thromboplastin time 
AST 
aspartate aminotransferase 
BL 
baseline 
BMI 
body mass index 
BP 
bullous pemphigoid 
BPDAI 
Bullous Pemphigoid Disease Area Index 
Caregiver 
A person of legal age from the participant’s social network 
(eg, family, relatives, friends), chosen by the participant. Once they 
receive the necessary training and are found competent by the 
authorized site staff to perform IMP administration, the caregiver 
can administer SC injections to the participant. 
CDA 
control of disease activity 
CFR 
Code of Federal Regulations 
C-GTI 
Composite Glucocorticoid Toxicity Index 
CIDP 
chronic inflammatory demyelinating polyneuropathy 
CIOMS 
Council for International Organizations of Medical Sciences 
CLEIA 
chemiluminescence enzyme immunoassay 
CMH 
Cochran-Mantel-Haenszel (test) 
CONSORT 
Consolidated Standards of Reporting Trials 
CR 
complete remission 
CSR 
clinical study report 
CT 
computerized tomography 
CTCAE 
Common Terminology Criteria for Adverse Events 
CWS 
cumulative worsening score (calculated from the C-GTI) 
DC 
disease control 
DIF 
direct immunofluorescence 
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Abbreviation/Term 
Expansion/Definition 
DLQI 
Dermatology Life Quality Index  
DRI 
dietary reference intake 
DSMB 
data and safety monitoring board 
ECG 
electrocardiogram 
eCRF 
electronic case report form 
EDC 
electronic data capture 
efgartigimod PH20 SC 
efgartigimod for SC administration coformulated with rHuPH20 
ELISA 
enzyme-linked immunosorbent assay 
EoTP 
end of treatment period 
ESD 
early study discontinuation 
ETD 
early treatment discontinuation 
FcRn 
neonatal crystallizable fragment receptor 
FSH 
follicle-stimulating hormone 
GCP 
Good Clinical Practice 
gMG 
generalized myasthenia gravis 
GMP 
Good Manufacturing Practice 
GTI 
Glucocorticoid Toxicity Index 
GTI-SL 
Glucocorticoid Toxicity Index Specific List 
HBsAg 
hepatitis B surface antigen 
HBV 
hepatitis B virus 
hCG 
human chorionic gonadotropin 
HCV 
hepatitis C virus 
HDL 
high-density lipoprotein 
HGRAC 
Human Genetic Resources Administration of China 
HR 
heart rate 
IB 
Investigator’s Brochure 
ICE 
intercurrent event 
ICF 
informed consent form 
ICH 
International Council for Harmonisation (of Technical 
Requirements for Pharmaceuticals for Human Use) 
IEC 
Independent Ethics Committee 
Ig 
immunoglobulin 
IGA-BP 
Investigator Global Assessment of Bullous Pemphigoid 
IgE 
immunoglobulin ε 
IgG 
immunoglobulin γ 
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Abbreviation/Term 
Expansion/Definition 
IGRA 
interferon gamma release assay 
IIF 
indirect immunofluorescence 
IM 
intramuscular 
IMP 
investigational medicinal product 
IND 
investigational new drug 
INR 
international normalized ratio 
IRB 
Institutional Review Board 
IRT 
interactive response technology 
Itch NRS 
Itch Numerical Rating Scale 
ITP 
immune thrombocytopenia 
IUD 
intrauterine device 
IUS 
intrauterine hormone-releasing system 
IV 
intravenous(ly) 
IVIg 
intravenous administration of immunoglobulin 
LDL 
low-density lipoprotein 
LRV 
lower reference value 
MCH 
mean corpuscular hemoglobin 
MCV 
mean corpuscular volume 
MedDRA 
Medical Dictionary for Regulatory Activities 
NAb 
neutralizing antibody 
NCI 
National Cancer Institute 
NCOD 
normalized cumulative oral corticosteroid dose 
OCS 
oral corticosteroid(s) 
OLE 
open-label extension (study) 
PBMC 
peripheral blood mononuclear cell 
placebo 
placebo for SC administration coformulated with rHuPH20 (dosing 
formulation) 
PD 
pharmacodynamic(s) 
PK 
pharmacokinetic(s) 
PPE 
personal protection equipment 
PR 
partial remission 
PRO 
patient-reported outcome (assessment) 
PT 
Preferred Term 
QoL 
quality of life 
QTcF 
Fridericia-corrected QT (interval) 
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Abbreviation/Term 
Expansion/Definition 
RBC 
red blood cell 
RDA 
recommended daily allowance 
rHuPH20 
recombinant human hyaluronidase PH20 
RNA 
ribonucleic acid 
SAE 
serious adverse event 
SAP 
statistical analysis plan 
SC 
subcutaneous(ly) 
SCR 
screening 
SE 
standard error 
SoA 
schedule of activities 
SOC 
System Organ Class 
SOP 
standard operating procedure 
TB 
tuberculosis 
TCS 
topical corticosteroid(s) 
TEAE 
treatment-emergent adverse event 
TNM 
tumor-node metastasis 
TP 
treatment period 
TV 
target value 
ULN 
upper limit of normal 
UNS 
unscheduled 
WBC 
white blood cell 
WHO 
World Health Organization 
WHODD 
World Health Organization drug dictionary 
WOCBP 
women of childbearing potential 
 
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The estimand framework for analysis of the primary endpoint applies only to part B of this study. 
The main attributes of the primary estimand will be: 
• Population: participants with BP who comply with the inclusion and exclusion criteria 
• Variable: proportion of participants who are in CR while receiving efgartigimod PH20 
SC or placebo and have been off OCS therapy for ≥8 weeks at week 36 summarized 
based on the odds ratio 
• Main intercurrent events (ICE): intake of intercurrent treatment or IMP discontinuation 
due to lack of efficacy before week 36 handled with a composite strategy 
Overall Design: 
In part A (a phase 2 evaluation), adult participants with moderate-to-severe BP will be randomized 
in a 1:1 ratio to receive double-blinded IMP, either efgartigimod PH20 SC or placebo. Part B (a 
phase 3 evaluation) is identical to part A in terms of design, with the goal of confirming the results 
obtained from part A in a separate, larger group of participants with BP. Efgartigimod PH20 SC will 
be administered at a dose of 
 mg (via  separate 1000 mg injections) on day 1 and day 8. After 
that, single injections of efgartigimod PH20 SC 1000 mg will be administered once weekly. Placebo 
will be administered using the same dose regimen. All participants will receive concurrent 
oral prednisone at a starting dosage of 0.5 mg/kg/day at baseline (or an equivalent dose of another 
OCS). Each participant’s OCS dosage can be adjusted throughout the study according to their BP 
disease status. 
Brief Summary: 
The main purpose of this study is to measure the effect of efgartigimod PH20 SC compared with 
placebo in adults with moderate-to-severe BP. The safety of efgartigimod will also be evaluated.  
Number of Participants (Parts A and B): 
This study will enroll approximately 40 participants in part A and 120 participants in part B. 
Note: Enrolled means the participant agrees to participate in the clinical study by completing the 
informed consent process. 
Study Arms and Duration: 
Participants in parts A and B will be randomized in a 1:1 ratio to receive efgartigimod PH20 SC or 
placebo. The durations of parts A and B are as follows: 
• Screening period: 2 to 3 weeks 
• Treatment period: 36 weeks  
• Treatment-free follow-up period: 7 weeks 
Data Monitoring/Other Committee: Yes  
 
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1.2. 
Schema 
Figure 1: 
Operationally Seamless Design of 2-Part Study 
 
BP=bullous pemphigoid; efgartigimod PH20 SC=efgartigimod for SC administration coformulated with rHuPH20; OCS=oral corticosteroids (prednisone or 
equivalent); OLE=open-label extension study (ARGX-113-2010); placebo=placebo for SC administration coformulated with rHuPH20; rHuPH20=recombinant 
human hyaluronidase PH20; SC=subcutaneous(ly) 
 
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IgG=immunoglobulin γ; IMP=investigational medicinal product (efgartigimod PH20 SC or placebo); INR=international normalized ratio; Itch NRS=Itch 
Numerical Rating Scale; OCS=oral corticosteroid(s); OLE=open-label extension (study); PBMCs=peripheral blood mononuclear cells; PK=pharmacokinetic; 
QoL=quality of life; rHuPh20=recombinant human hyaluronidase PH20; SCR=screening; TB=tuberculosis; UNS=unscheduled; WOCBP=women of 
childbearing potential. 
Note: (x)=visit activities that are optional are only required under specific circumstances. 
a The screening period may be extended by a maximum of 7 days for logistical or administrative reasons (eg, receipt of laboratory results). 
b The treatment period consists of weekly visits, starting with the BL visit and ending with the EoTP visit. 
c Follow-up visits are only applicable for participants who choose not to roll over to the OLE study ARGX-113-2010. 
d Mandatory on-site visits must be performed as indicated. However, the visits at weeks 8 and 16 may also be performed at home, by qualified site staff, for a 
participant who has achieved CDA. In these cases, collection of the PK, PD, and immunogenicity blood samples and weight measurement are not required. 
e Weekly visits that are not designated as mandatory on-site visits may be performed at home if the participant has achieved CDA. Home administration of IMP 
will not be permitted until week 5. During home visits, IMP will be administered by a home nurse. In case of permanent IMP discontinuation, participants will 
attend mandatory on-site visits only. 
f The ETD visit must be performed when IMP is discontinued before the EoTP visit; the study site should make every effort to perform this visit within 7 days 
of the participant’s last IMP dose. Participants will remain in the study (provided that they have not withdrawn consent) and will continue to participate in 
study visits as scheduled, only without IMP administration. Rescue therapy may be initiated at this visit. 
g The ESD visit must be performed when the participant either withdraws consent or is permanently discontinued from the study. The study site must make 
every effort to perform this visit within 7 days of the participant's last IMP dose. 
h An unscheduled visit may be performed if the participant has (or suspects they have) new BP lesions or has other issues requiring site staff intervention, such 
as notable weight change. The investigator will decide which assessments to conduct based on the purpose of the unscheduled visit. In case of relapse, 
IGA-BP, BPDAI, and Itch NRS assessments must be performed, and participants should return to weekly on-site visits until CDA is achieved again. 
i Histopathology/DIF are performed only if positive test results are not available as part of the participant’s medical history. 
j All vaccinations received before the study should be recorded as part of the participant’s prior medication history, while all vaccinations received during the 
study should be recorded as concomitant medications. 
k Weight may be measured when other weekly visits are performed on-site. 
l WOCBP must have a negative serum pregnancy test. Postmenopausal female participants must have a serum FSH test to confirm postmenopausal status. 
m The day 10 PK blood sample will only be collected during part A of the study from at least 28 participants. 
n For study visits that occur at home (in between mandatory on-site visits), the investigator will call the participant once weekly to assess BP disease status and 
review/adjust the participant's concurrent prednisone (or equivalent) dosage. 
o At BL (week 0 [day 1]) and week 1 (day 8), 
 mg of IMP (efgartigimod PH20 SC or placebo) will be administered via  SC injections (Table 6). At weeks 
2 through 35, 1000 mg of IMP (efgartigimod PH20 SC or placebo) will be administered via a single SC injection. 
 
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2. 
INTRODUCTION 
The proposed study is an operationally seamless 2-part, phase 2/3, prospective, global, 
multicenter, randomized, double-blinded, placebo-controlled study to investigate the efficacy, 
safety, tolerability, immunogenicity, participant-reported outcome measures (including those 
assessing quality of life [QoL]), pharmacokinetics (PK), and pharmacodynamics (PD) 
of efgartigimod PH20 SC (efgartigimod coformulated with recombinant human PH20 
for subcutaneous [SC] injection) in adult participants with moderate-to-severe bullous 
pemphigoid (BP). This study intends to demonstrate that efgartigimod PH20 SC is an effective 
and safe treatment for BP, providing participants with control of disease activity (CDA) and 
eventually remission while reducing their cumulative exposure to oral corticosteroids (OCS). 
The study will be conducted in 2 parts: 
• Part A is a phase 2 evaluation which intends to provide proof of concept for the 
therapeutic activity of efgartigimod PH20 SC in participants with BP. 
• Part B is a phase 3 evaluation which intends to confirm the results obtained from part 
A in a separate, larger group of participants with BP. 
Parts A and B include different sample sizes, endpoints, and statistical analyses; otherwise, both 
parts are identical in schedule, structure, assessments, and conduct. 
To allow for convenient SC injection of efgartigimod, participants will be administered 
efgartigimod PH20 SC, a solution of efgartigimod coformulated with recombinant human 
hyaluronidase PH20 (rHuPH20). rHuPH20 is currently being used in coformulations with 
approved therapeutic antibodies to facilitate SC injection of volumes >2 mL. 
Efgartigimod PH20 SC or placebo will be administered once weekly throughout the 36-week 
treatment period. All participants will also receive concurrent therapy with OCS: oral prednisone 
at a starting dosage of 0.5 mg/kg/day (or an alternate OCS of equivalent dose strength) at 
baseline. The OCS dosage will be adjusted according to each participant’s BP disease status 
throughout the study. 
Additional information on efgartigimod is provided in the current IB. 
2.1. 
Study Rationale 
BP is a subepidermal autoimmune blistering disease (AIBD) that predominantly affects older 
adults. It is a chronic disease that significantly impacts morbidity and QoL; additionally, the 
disease can worsen spontaneously, even when the patient is treated with the current standard of 
care. The pathogenesis of BP is driven by IgG and IgE autoantibodies against the 
hemidesmosomal proteins BP180 and BP230, acting as key antigens for pathogenic 
autoantibodies. These pathogenic autoantibodies are understood to directly interfere with 
autoantigen adherence, activation of complement, recruitment of inflammatory cells 
(eg, eosinophils), and release of proteolytic enzymes, causing skin blistering and pruritus. 
IgG autoantibodies against BP180 and BP230 have been demonstrated to induce BP-like 
symptoms in animal models, and disease activity is associated with serum levels of anti-BP180 
autoantibodies.1,2 
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At this time, no therapies are specifically licensed for the treatment of patients with BP. The 
current standard of care for BP is treatment with topical corticosteroids (TCS) or OCS, either of 
which can be combined with conventional immunosuppressant therapy. Unfortunately, 
corticosteroid therapy in patients with BP typically causes comorbidities, which can be severe 
and even life-threatening, especially in older adults. As a result, patients with BP have a higher 
mortality rate than their peers, even when their disease is being treated. Alternative therapies 
targeting IgG (eg, IV administration of immunoglobulin [IVIg], plasma exchange, or protein A 
immunoadsorption) or biologics (eg, rituximab, omalizumab) have shown potential in small 
numbers of patients with BP. However, the efficacy and safety of these treatments have not been 
assessed in registrational studies.3,4,5 
Efgartigimod, a neonatal crystallizable fragment receptor (FcRn) antagonist, blocks FcRn-
mediated recycling of IgG, effectively reducing IgG levels, including IgG autoantibody levels. 
The formulation for subcutaneous (SC) administration of efgartigimod PH20 SC (efgartigimod 
coformulated with recombinant human hyaluronidase PH20 [rHuPH20]) represents a rational 
and innovative therapeutic approach to autoimmune diseases mediated by IgG autoantibodies, 
such as BP. 
This study will determine whether sustained remission is attainable with efgartigimod PH20 SC 
treatment (compared with placebo) while minimizing cumulative OCS exposure. 
efgartigimod PH20 SC will also be evaluated for efficacy, safety, PK/PD, immunogenicity, and 
impact on the QoL of study participants. 
2.2. 
Background 
BP is the most common autoimmune blistering skin disease, with an estimated annual incidence 
of 2.4 to 23 cases per million individuals. However, among people >80 years of age, 
the incidence ranges from 190 to 312 cases per million individuals.6,7 The disease has a poor 
prognosis, which is directly attributable to the advanced age of the patient population 
and the comorbidities that can be present in this population. A recent meta-analysis calculated 
that the relative risk of death among patients with BP during a 1-year period is 2.93 times greater 
that of the general worldwide population (adjusted for age and sex).8 Studies examining 
the all-cause mortality among patients with BP beyond 1 year have reported higher death rates 
in the first year (20% to 27%) than in subsequent years (9% to 16%). The main causes of death 
were infections and cardiovascular disorders, which are attributable to both the older age 
of patients with BP and their use of corticosteroids and/or immunosuppressants. 
In BP, the disruption of the dermal-epidermal junction by pathogenic autoantibodies results 
in large, tense bullae on the skin, progressing to epidermal erosion, crusting, and urticarial plaque 
formation. Without treatment, BP ultimately progresses to life-threatening complications, 
including (but not limited to) severe infections, functional impairment of vital organs, 
and iatrogenic conditions. 
Corticosteroids (either topical or oral) are currently the first-line therapy for the treatment of 
patients with BP. For BP that is either localized or mild/moderate in severity, medical authorities 
recommend application of high-dose TCS of strong potency (such as clobetasol propionate at 
doses from 20 to 40 g/day).9,10 Unfortunately, the use of TCS at such high doses results in a 
substantial systemic absorption and severe skin atrophy.11 
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For patients who have widespread or moderate-to-severe BP, OCS therapy is the standard of care 
among most practitioners. Unfortunately, OCS cause significant toxicity in patients with BP, 
because the cumulative corticosteroid exposure that is typically required to successfully manage 
the disease is high. Thus, physicians who treat patients with BP must provide the optimal 
corticosteroid dose to successfully manage the disease, achieve CDA or complete/partial 
remission (CR/PR), and prevent subsequent relapse, while also mitigating the adverse effects of 
corticosteroids by minimizing the amount that they prescribe to their patients. 
Alternative adjuvant treatments to corticosteroids have been evaluated in patients with severe BP 
or in those who expressed corticosteroid resistance, including IVIg, plasma exchange, rituximab, 
and omalizumab. These treatments have either shown inconsistent results, proven to be 
prohibitively complicated and/or expensive, induced significant side effects in their respective 
populations of patients with BP, or produced encouraging results only to have significant 
portions of those who responded to treatment ultimately relapse shortly thereafter.12,13,14,15,16 
Additionally, dapsone and tetracyclines (with or without nicotinamide) have also been evaluated 
as treatments for patients with BP who cannot be administered OCS; however, the efficacy of 
these treatments has been shown to be modest, at best.17,18 
In summary, there is currently an unmet medical need for new BP treatments that provide rapid 
CDA and remission, minimize (or even prevent) relapse, and reduce the burdens placed on 
patients due to cumulative corticosteroid exposure. 
2.3. 
Benefit/Risk Assessment 
More detailed information about the known and expected benefits and risks of efgartigimod 
PH20 SC is provided in the current IB. 
2.3.1. 
Risk Assessment 
Overall, available data confirm that efgartigimod has been well tolerated across studies in 
different indications and has an acceptable safety profile. 
 
 
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Table 2: 
Potential Risks and Mitigation Strategies for ARGX-113-2009 
Potential clinically significant 
risk 
Summary of data/ 
rationale for risk  
Mitigation strategy 
IMP 
Serious infection 
Efgartigimod reduces IgG 
levels, potentially hindering 
immune response and increasing 
the risk for infection. 
Exclude participants with 
clinically significant active 
infection that is not sufficiently 
resolved before baseline in the 
investigator’s opinion 
(Section 5.2). 
Infections are considered AESIs 
(Section 8.4.7). Monitor for 
infections and temporarily 
interrupt IMP dosing as 
specified in Section 7.1. 
Infusion/injection-related 
reactions 
All therapeutic proteins can 
elicit immune responses, 
potentially resulting in 
hypersensitivity or allergic 
reactions such as rash, urticaria, 
angioedema, serum sickness, 
and anaphylactoid or 
anaphylactic reactions. Overall, 
the frequency of 
infusion/injection-related 
reactions in the studies was low. 
Pretreatment to prevent 
infusion/injection-related 
reactions is not required. 
Participants will be monitored 
for infusion/injection-related 
reactions. 
Participants and/or their 
caregivers who receive training 
on self-administration will be 
educated on symptoms of 
infusion/injection-related 
reactions. 
Infusion/injection-related 
reactions are considered AEs of 
clinical interest (Section 8.4.8).  
Injection site reactions 
Most AEs have been mild, 
transient injection site reactions, 
including erythema, pain, 
bruising, pruritus, burning, 
tenderness, edema, induration, 
irritation, paresthesia, numbness, 
and rash. Moderate injection site 
reactions occurring less 
frequently include burning, 
erythema, pain, and numbness. 
Localized injection site reactions 
are frequently observed in 
studies in which efgartigimod is 
comixed with PH20 and 
administered SC. 
Continuously monitor 
participants for injection site 
reactions. 
Injection site reactions are 
considered AEs of clinical 
interest (Section 8.4.8). 
 
 
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2.3.3. 
Overall Benefit-Risk Conclusion 
The favorable balance between the risks and anticipated efficacy/benefits supports the 
administration of efgartigimod PH20 SC to participants with BP in ARGX-113-2009. 
More detailed information about the known and expected benefits and risks of efgartigimod 
PH20 SC is provided in the current version of the IB. 
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4. 
STUDY DESIGN 
4.1. 
Overall Design 
This is an operationally seamless 2-part, phase 2/3, prospective, global, multicenter, randomized, 
double-blinded, placebo-controlled study to investigate the efficacy, safety, tolerability, 
immunogenicity, participant-reported outcome measures (including QoL assessments), PK, and 
PD of efgartigimod PH20 SC in adult participants with moderate-to-severe BP. 
During both parts of the study, participants will be administered investigational medicinal 
product (IMP): efgartigimod PH20 SC or placebo) once weekly for 36 weeks. All participants 
will also receive concurrent therapy with OCS, ie, prednisone at a starting dosage of 
0.5 mg/kg/day at baseline, or an alternate OCS at an equivalent dose strength. The OCS dosage 
will be adjusted according to each participant’s BP disease status throughout the study. 
4.1.1. 
Description of Part A and Part B 
A 2-part schematic of the overall study design is presented in Section 1.2; brief descriptions 
of both parts of ARGX-113-2009 are presented below: 
Part A is a phase 2, proof-of-concept study in which approximately 40 adult participants with 
moderate-to-severe BP will be randomized in a 1:1 ratio to receive either efgartigimod PH20 SC 
or placebo. The main goal of part A is to determine whether efgartigimod PH20 SC is effective 
in the treatment of participants with BP via assessment of the study’s primary endpoint:  
the proportion of participants who are in CR while receiving efgartigimod PH20 SC or placebo 
and have been off OCS therapy for ≥8 weeks at week 36. Other part A objectives and endpoints 
are listed in Table 3. 
An interim analysis will be conducted from data obtained from all part A participants through 
the week 26 visit. The interim analysis will be conducted to assess the primary endpoint, assess 
several of the study’s secondary endpoints, confirm the appropriate sample size for part B 
of the study, and determine whether the efficacy results observed through week 26 warrant 
continued study of efgartigimod PH20 SC for the treatment of participants with BP (futility 
analysis). The part A interim analysis is described in Section 9.4. 
The final analysis of part A data will be performed after its last participant completes their last 
visit (Section 4.4). 
Part B is a phase 3 confirmatory study in which approximately 120 adult participants with 
moderate-to-severe BP will be randomized in a 1:1 ratio to receive either efgartigimod PH20 SC 
or placebo. The main goal of part B is to confirm the results obtained for the primary endpoint 
from part A (the proportion of participants who are in CR while receiving efgartigimod PH20 SC 
or placebo and have been off OCS therapy for ≥8 weeks at week 36), but in a separate, larger 
group of participants with BP. Other part B objectives and endpoints are listed in Table 4. The 
proposed order of the key secondary endpoints for part B may be adjusted based on the results 
obtained from the part A interim analysis (Section 9.1.1). 
4.1.2. 
Conduct of Both Parts A and B 
Parts A and B of the study have different sample sizes; otherwise, both parts are identical 
in schedule, structure, assessments, and conduct. Both parts A and B have screening periods 
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of up to 2 weeks (extendable to 3 weeks per investigator discretion) followed by treatment 
periods of 36 weeks, during which participants will receive either efgartigimod PH20 SC 
or placebo. Finally, all part A and part B participants who complete the end of treatment period 
(EoTP) visit at week 36 will be offered the option to either enroll in an open-label extension 
(OLE) study or complete a 7-week treatment-free follow-up period. 
To enter the study, participants must have a diagnosis of BP that complies with the international 
guidelines for the diagnosis of BP.19,20,21 The diagnosis of BP must be confirmed by all 3 of the 
following methods before the participant is randomized to a study arm (refer to inclusion 
criterion 3): 
• Clinical signs of BP (presence of bullae), with or without the presence of urticarial, 
eczematous, or erythematous plaques, and with or without pruritus. 
• Histopathological and direct immunofluorescence (DIF) examination of a cutaneous 
biopsy. 
• Serology by indirect immunofluorescence (IIF), chemiluminescence enzyme 
immunoassay (CLEIA), or ELISA. 
In part B, study participants will be stratified by disease history (newly diagnosed or relapsing) 
and disease severity (moderate BP [an Investigator Global Assessment of Bullous Pemphigoid 
{IGA-BP} score of 3] or severe BP [an IGA-BP score of 4]). The participants will be randomized 
in a 1:1 ratio to receive either efgartigimod PH20 SC or placebo as follows: 
• Efgartigimod PH20 SC will be administered by SC injection on day 1 and day 8 at a 
dose of 
 mg (administered as  separate SC injections of 1000 mg each), 
followed by single weekly SC injections of 1000 mg from week 2 through week 35. 
• Placebo (injection vehicle coformulated with 2000 U/mL of rHuPH20) 
will be administered using the same regimen described above. 
All participants will also receive concurrent therapy with OCS, ie, prednisone at a starting 
dosage of 0.5 mg/kg/day at baseline, or an alternate OCS at an equivalent dose strength. 
The OCS dosage will be adjusted according to each participant’s BP disease status throughout 
the study. BP disease status terminology definitions are listed in Section 4.1.3 and the oral 
prednisone dose adjustment procedure is described in Section 6.8.1.3. 
Efficacy and QoL measures to be assessed during the study (other than BP disease status 
assessment) include the following: 
• Investigator Global Assessment of Bullous Pemphigoid (IGA-BP) 
• Bullous Pemphigoid Disease Area Index (BPDAI) 
• Itch Numerical Rating Scale (Itch NRS) 
• EuroQol 5-Dimension 5-Level (EQ-5D-5L) 
• Dermatology Life Quality Index (DLQI) 
• Autoimmune Bullous Disease Quality of Life (ABQoL) questionnaire. 
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Brief descriptions of these efficacy and QoL measurements are provided in Section 8.2; the time 
points when they are administered during the study are provided in the SoA (Table 1). 
PK measures include the quantification of efgartigimod serum concentrations. PD measures 
include the quantification of total IgG serum levels, anti-BP180 and anti-BP230 antibodies, and 
. Refer to the SoA (Table 1) for the time points when PK and PD blood samples 
are collected during the study; each of the study’s PK and PD measures is briefly described in 
Section 8.5 and Section 8.6, respectively. 
Immunogenicity measures include the determination of both ADAs against efgartigimod in 
serum and antibodies against rHuPH20 in plasma. Refer to the SoA (Table 1) for the time points 
when immunogenicity blood samples are collected during the study; additional information 
regarding the immunogenicity measures is presented in Section 8.9. 
Safety measures for the study include the following: 
• Physical examinations 
• Height, body weight, and vital signs measurements 
• Electrocardiograms (ECGs) 
• Recording of medical, surgical, and vaccination histories 
• Clinical safety laboratory tests, including clinical chemistry, hematology, coagulation, 
urinalysis, and virus serology 
• Serum and urine pregnancy tests for women of childbearing potential (WOCBP) 
or a follicle-stimulating hormone (FSH) test to confirm postmenopausal status 
• The Glucocorticoid Toxicity Index (GTI), consisting of the Composite Glucocorticoid 
Toxicity Index (C-GTI) and the Glucocorticoid Toxicity Index Specific List (GTI-SL) 
• Recording of adverse events (AEs), serious adverse events (SAEs), and adverse 
events of special interest (AESIs) 
AE, SAE, and AESI reporting are described in detail in Section 8.4; refer to Section 8.3 for brief 
descriptions of the other safety measures. 
In addition, selected study sites will participate in the following substudies: 
• Photography substudy: Site staff will take photographs of bullous lesions located 
at various anatomical regions of participants per the discretion of the investigator. 
As a guidance, time points of baseline, CDA, CR, and relapse are indicated; however, 
photographs may also be taken at intermediate time points (Section 8.10). 
• Vaccination response substudy: This substudy will investigate the influence 
of efgartigimod PH20 SC treatment on historical protective antibody titers and 
humoral and/or cellular responses to vaccines received during the study among 
participants who provide additional consent to participate in this substudy. 
(Section 8.3.6.2). 
Participants and/or their caregivers (defined in Abbreviations and Definitions) will be invited to 
receive training for (self-)administration of the IMP. In this study, participants (and/or their 
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caregivers) will only be permitted to (self-)administer IMP at on-site visits under the supervision 
of site staff, and only after they have completed training and are determined competent enough 
to do so by site staff. Successful completion of this training is intended to enable IMP 
self-administration or caregiver-supported administration at home in the OLE study 
ARGX-113-2010. 
4.1.3. 
Bullous Pemphigoid Disease Status Terminology to Be Used in the Study 
The following terms and definitions will be used in ARGX-113-2009 to conduct the study, 
monitor BP disease status, and assess the study endpoints aligned with consensus terminology 
(according to Murrell et al. in 201222): 
• Control of disease activity (CDA) – the point at which new lesions cease to form 
and established lesions begin to heal, and pruritic symptoms start to abate. 
• Treatment failure – the absence of CDA after being administered oral prednisone 
at 0.75 mg/kg/day (or equivalent OCS) for 3 weeks. The investigator has the option 
to add a fourth week of therapy with oral prednisone 0.75 or 1 mg/kg/day (or 
equivalent) (based on clinical judgment) before declaring treatment failure. 
• Transient lesions – new lesions that heal within 1 week or pruritus lasting less than 
1 week. 
• Nontransient lesions – new lesions that do not heal within 1 week or pruritus 
continuing longer than 1 week. 
• Minimal OCS therapy – an oral prednisone dosage of ≤0.10 mg/kg/day (or an 
equivalent dose of another OCS). 
• Complete remission (CR) – the absence of new lesions, complete healing of existing 
lesions, and absence of pruritus (except postinflammatory changes, including 
hyper/hypopigmentation or skin damage). 
• Partial remission (PR) – the presence of only new transient lesions. 
• Relapse – appearance of 3 or more new lesions a month (blisters, eczematous lesions, 
or urticarial plaques) or at least 1 large (>10 cm diameter) eczematous lesion or 
urticarial plaque that do not heal within 1 week, or extension of established lesions or 
daily pruritus in a participant who has achieved CDA. 
ALSO: For the purposes of this protocol, “oral prednisone” refers to doses/dosages 
of prednisone or an alternate, equivalent OCS (eg, prednisolone). 
4.2. 
Scientific Rationale for Study Design 
4.2.1. 
Rationale for Selection of a Phase 2/3 Study 
Efgartigimod IV and/or efgartigimod PH20 SC have been investigated in clinical studies 
of healthy participants and participants with gMG, primary ITP, CIDP, and pemphigus. 
The clinical pharmacology, efficacy, and safety/tolerability results from these studies 
are described in Section 5 of the efgartigimod IB. 
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The results obtained from the phase 2 study of efgartigimod IV in participants with pemphigus 
(ARGX-113-1701) are of particular importance, because they demonstrated that efgartigimod 
can be an effective therapy in patients who have an IgG-driven autoimmune disease involving 
the skin (similar to BP). The results from this phase 2 study, coupled with the body of results 
obtained from other phase 2 and phase 3 studies of efgartigimod for several other autoimmune 
diseases, lead the sponsor to believe that it is appropriate to conduct a 2-part, phase 2/3 study to 
investigate the efficacy, safety, and other effects of efgartigimod PH20 SC in participants with 
BP. 
The sponsor recognizes that efgartigimod PH20 SC has not yet been administered to participants 
with BP and that the pathophysiology of BP is more complex than that of pemphigus. As a 
result, ARGX-113-2009 has been designed to ensure the safety of its participants by including 
guidelines for stopping treatment with efgartigimod PH20 SC and initiating rescue therapy using 
standard of care for BP. Additionally, the study includes an interim analysis (Section 9.4) that 
will be performed using week 26 data collected from participants who are enrolled in part A. 
This analysis is being conducted to assess the study’s primary endpoint (Table 3) at week 26, 
assess selected secondary endpoints (Table 3), determine the appropriate sample size for part B 
of the study, and determine whether the efficacy results observed through week 26 warrant 
continued study (futility analysis; Section 9.4). 
4.2.2. 
Rationale for the Selection of the Participant Population 
To ensure that the study population aligns with the demographics of the general population 
of patients with BP (which occurs predominantly in people ≥65 years of age), ARGX-113-2009 
study participants will include males and females who have reached the age of consent with no 
upper age limit. 
The sponsor has designed the participant eligibility criteria of ARGX-113-2009 to comply with 
international guidelines for the diagnosis of BP (criteria listed in Section 4.1),19,20,21 which will 
ensure that the study population is representative of the general worldwide population of patients 
with BP. 
Participants will receive either efgartigimod PH20 SC or placebo. All participants will receive 
concurrent therapy with OCS, ie, prednisone at a starting dosage of 0.5 mg/kg/day at baseline or 
an alternate OCS at an equivalent dose strength. The OCS dosage will be adjusted according to 
each participant’s BP disease status throughout the study (disease status terminology is provided 
in Section 4.1.3). 
ARGX-113-2009 will enroll participants with moderate-to-severe BP. This subgroup of patients 
was selected because it represents those patients in the general population who have the greatest 
medical need for new BP treatment modalities that can reduce their cumulative OCS 
exposure.19,23,24 
The IGA-BP will be used to assess the severity of BP for each participant. It is a new assessment 
tool that was developed in 2021 by AIBD experts and is currently being used (along with 
the BPDAI) in other clinical studies of BP. The IGA-BP categorizes the severity of BP 
on a numerical scale of 0 to 4, with a score of 0 representing no overt signs of BP and a score 
of 4 representing severe BP. Given that this study is designed to investigate the effects 
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of efgartigimod PH20 SC on participants with moderate-to-severe BP, ARGX-113-2009 will 
enroll participants whose IGA-BP score is 3 or 4. 
Patients with BP can have comorbidities that may limit day-to-day functioning. Moreover, 
ARGX-113-2009 will not have an upper age limit for participation; therefore, the sponsor 
anticipates the study to include a large number of older adult participants with BP. Also, the 
sponsor wants to ensure that study participants will be able to adequately complete 
patient-reported outcome (PRO) assessments without placing any undue burden on them. 
Therefore, ARGX-113-2009 participants will be required to have a Karnofsky Performance 
Index (Section 10.5) score of ≥60%. 
Atypical types of BP and AIBDs other than BP may have pathogeneses and disease courses that 
differ from those of typical BP. Therefore, participants with other AIBDs or atypical forms of BP 
(listed in exclusion criterion 1) will be excluded from participating in the study. 
Participants with BP who have been treated with any systemic therapies for the disease other 
than corticosteroids (listed in exclusion criterion 3B) but still wish to participate in the study will 
be required to complete a wash-out period before they can begin study participation 
(Section 5.5). The durations of these required wash-out periods (described in Section 5.5) were 
selected based on the known PK properties of each of these therapies. [Note: prior therapy with 
conventional immunosuppressants (eg, azathioprine, cyclophosphamide, methotrexate, 
mycophenolate mofetil) or with dapsone require no wash-out period; however, these therapies 
must be discontinued before baseline.] 
4.2.3. 
Rationale for the Selection of the Oral Corticosteroid Dosing Regimen 
The oral prednisone starting dosage of 0.5 mg/kg/day (or equivalent OCS) and the subsequent 
dosage modification regimen (described in Section 6.8.1.3) are based on recommendations 
from European and Japanese guidelines25,26 Oral prednisone doses will be adjusted throughout 
the study for each participant based on their current BP disease activity to maintain CDA 
and to avoid relapse (Section 6.8.1.3). 
4.2.4. 
Rationale for the Selection of Study Endpoints 
4.2.4.1. 
Primary Endpoint 
The primary endpoint was selected based on the BP disease status terminology described by 
Murrell et al. in 2012,22 in which the term CR off therapy is defined as “the absence of new 
or established lesions or pruritus while the patient is off all therapy for at least 2 months.” 
Achieving a complete and stable absence of BP symptoms represents a clinically meaningful 
outcome and is expected to result in a significant improvement in patient quality of life. 
Other than IMP, the only concurrent BP therapy permitted in ARGX-113-2009 is OCS; 
therefore, within the parameters of this study, “off OCS therapy” is considered equivalent 
to the AIBD expert definition of “off therapy.”22 
In ARGX-113-2009, tapering of concurrent OCS therapy will be performed in a manner 
consistent with treatment guidelines,24,25,26 while once-weekly dosing of IMP will be continued 
until the end of the 36-week treatment period. Tapering, and ultimately eliminating, concurrent 
OCS therapy reduces the risks of developing comorbidities associated with steroid therapy. 
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Avoiding such risks is particularly important for older adults (like those with BP), who 
historically develop serious comorbidities like osteoporosis, diabetes, and glaucoma following 
prolonged exposure to high doses of OCS.27,28,29 
ARGX-113-2009 will assess whether participants have remained in CR while receiving 
efgartigimod PH20 SC or placebo and after having been off OCS for at least 8 weeks at the end 
of the 36-week treatment period. Achieving a sustained response to treatment is of particular 
importance to patients with BP, as the available evidence shows that many patients who achieve 
CR subsequently relapse within months.30,31 
The selection of a 36-week treatment period is based on international guidelines for the treatment 
of BP, which recommend that systemic steroid doses should be tapered gradually so that minimal 
OCS therapy is achieved within 4 to 6 months after beginning treatment, and that OCS therapy 
may be subsequently stopped after the patient has sustained CR for 3 to 6 months. Therefore, 
a 36-week treatment period (approximately 9 months) is considered an appropriate duration to 
allow participants to achieve CR and stop concurrent OCS therapy.24 
4.2.4.2. 
Secondary Efficacy Endpoints 
4.2.4.2.1. Key Secondary Endpoints (Part B Only) 
Rationales for the selection of the key secondary efficacy endpoints for part B are summarized 
below. [Note: “Key” secondary endpoints are subject to hierarchical testing and alpha-control 
during part B only. During part A of the study, they will be assessed as standard secondary 
efficacy endpoints (without hierarchical testing/alpha-control).] 
1. Cumulative dose of OCS from baseline to week 36: Currently, the standard of care 
for moderate-to-severe BP is OCS. Unfortunately, exposure to high doses of OCS results 
in an increased risk of developing serious comorbidities, especially in older adults. As a 
result, a goal in BP treatment is to reduce the patient’s cumulative exposure to OCS. 
Therefore, this endpoint was selected to ascertain whether participants who are 
administered efgartigimod PH20 SC have lower cumulative OCS exposure values than 
participants who are administered placebo. 
2. Proportion of participants who achieve an IGA-BP score of 0 while receiving 
efgartigimod PH20 SC or placebo and have been off OCS therapy for ≥8 weeks at week 
36: This endpoint was selected because an IGA-BP score of 0 (defined in Section 4.2.2 
and Section 10.6) represents a complete absence of BP skin lesions. As described in 
Section 4.2.4.1, the ability to remain free of clinical disease activity while limiting one’s 
cumulative exposure to OCS for prolonged periods is particularly important for older 
adults with BP, who are more susceptible to serious comorbidities due to prolonged OCS 
exposure.27,28,29 
3. Proportion of participants who achieve CDA while receiving efgartigimod PH20 SC or 
placebo and remain free of relapse through week 36: This endpoint was selected because 
it is important to ascertain whether treatment with efgartigimod PH20 SC provides 
participants with BP prolonged and sustained relief from BP symptoms, and whether 
efgartigimod PH20 SC effectively prevents relapse. 
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4. Proportion of participants who are in CR while receiving efgartigimod PH20 SC 
or placebo and have been receiving minimal OCS therapy for ≥8 weeks at week 36: 
This endpoint was selected for the same reasons as those described for key secondary 
endpoint 3. 
5. Changes from baseline in the 24-hour average itch score from the Itch NRS: As noted 
in Section 2.1, pruritus is among the signs/symptoms of BP; moreover, the itching that 
is associated with BP can be debilitating. This endpoint will determine if treatment with 
efgartigimod PH20 SC provides relief from pruritus, which is considered a clinically 
meaningful disease improvement. 
4.2.4.2.2. Additional (or Other) Secondary Efficacy Endpoints (Parts A and B) 
The additional secondary efficacy endpoints of this study (listed in Table 3 and Table 4) were 
selected to further characterize the efficacy of efgartigimod PH20 SC in participants with BP. 
4.2.4.3. 
Safety Endpoints 
The safety, tolerability, and health impact endpoints selected for this study are those considered 
to be standard for any clinical study evaluating the safety of an IMP. 
4.2.4.4. 
Pharmacokinetics, Pharmacodynamics, and Immunogenicity Endpoints 
The PK, PD, and immunogenicity endpoints selected for this study are those considered 
to be standard for any clinical study evaluating the manner in which an immunological IMP 
is processed by the body and how it targets the immune system. 
4.2.5. 
Rationale for the Selection of Study Assessments 
The BP disease assessment terminology and definitions applied in this study were adapted from 
those established by Murrell et al. in 2012.22 These terms and definitions are internationally 
accepted by AIBD medical experts and clinicians who treat patients with BP. 
Disease severity and symptoms will be monitored throughout the study using the IGA-BP scale, 
the BPDAI, and the Itch NRS. The IGA-BP was developed in 2021 by medical experts in the 
field of AIBDs, and it is currently being used (along with the BPDAI) in other clinical studies of 
therapies for BP. The IGA-BP scale has specific guidance on equating the extent of skin lesions 
to disease severity (Section 10.6), while the BPDAI score also considers the presence of mucosal 
lesions (Section 10.7).2 Pruritic symptoms will be measured using the Itch NRS 
(Section 10.8).32,33,34 
The BPDAI2 and the Itch NRS32,33,34 are validated and internationally accepted measures of BP 
disease severity and pruritus intensity, respectively. 
The EQ-5D-5L,35 DLQI,36 and ABQoL37 are validated and internationally accepted measures 
of patient QoL. 
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4.3. 
Justification for Selection of the Treatment Regimen and Dose 
In ARGX-113-2009, study participants will either receive efgartigimod PH20 SC or placebo. 
At the time of this protocol’s initial approval, efgartigimod PH20 SC had been safely 
administered to healthy participants and participants with gMG, primary ITP, CIDP, 
and pemphigus. 
The SC route of administration offers convenience for participants with BP, their caregivers, 
and health care providers, because SC injections are easier to administer than IV injections. 
Additionally, the coformulation of efgartigimod with rHuPH20 permits SC dosing of higher 
volumes than typical SC injections, because rHuPH20 reduces resistance to fluid flow and 
increases dispersion and absorption of injected medicines and fluids, which allows for a larger 
volume to be injected with limited skin swelling or pain. 
In BP, patients typically achieve CDA, PR, or CR only after receiving treatment for several 
weeks; sometimes even months of treatment are required before CR or PR is achieved. 
Moreover, patients with BP tend to relapse within a few months after achieving remission.30,31 
Therefore, studies of BP must be of sufficient duration to assess the durability of efficacy of the 
IMP and the sustainability of remission while the patient is off OCS therapy. It is for these 
reasons that the sponsor has selected a 36-week treatment period for ARGX-113-2009. 
Initially, the clinical development of efgartigimod was based on IV dosing. Results from phase 1 
studies in healthy participants, phase 2/3 studies in participants with gMG, a phase 2 study in 
participants with ITP, and PK/PD modeling analysis showed that efgartigimod IV 10 mg/kg 
administered once weekly achieved nearly maximal reduction in serum IgG levels. Studies of 
participants with gMG and ITP also showed that efgartigimod IV 10 mg/kg administered once 
weekly resulted in clinical efficacy coupled with reductions in serum pathogenic autoantibody 
levels while maintaining a favorable safety/tolerability profile. 
In ARGX-113-2009, participants will be administered efgartigimod PH20 SC as a fixed dose 
(rather than a dose that is adjusted weekly based on body mass), because this is more convenient 
for both the study participants and site staff. Results from a PK/PD modeling analysis indicated 
that efgartigimod PH20 SC 1000 mg administered once weekly would result in reductions in 
total IgG serum levels equivalent to a weekly dose of efgartigimod IV 10 mg/kg. Results from a 
phase 1 study comparing the PK and PD properties of IV and SC administration of efgartigimod 
in healthy participants (ARGX-113-1907) confirmed that 4 once-weekly injections of 
efgartigimod PH20 SC 1000 mg were noninferior to 4 once-weekly infusions of efgartigimod IV 
10 mg/kg in reducing total IgG serum levels. Therefore, the sponsor has selected 
efgartigimod PH20 SC 1000 mg administered once weekly as the maintenance dose for 
ARGX-113-2009. 
Still, given that IgG autoimmune activity is considered to cause the pathophysiology of BP, 
any therapy that targets this activity should be designed so that maximum reduction of total IgG 
serum levels occurs as rapidly as possible. Therefore, ARGX-113-2009 participants who are 
assigned to the efgartigimod PH20 SC arm will receive a dose of 
 mg at baseline (week 0) 
and week 1. Initiation of treatment with 2 once-weekly doses of efgartigimod PH20 SC 
 mg 
is predicted to achieve a nearly maximal reduction in total IgG serum levels within 2 weeks that 
is similar to that for once-weekly injections of efgartigimod PH20 SC 1000 mg at steady state. 
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4.4. 
End of Study Definition 
The end-of-study definitions for ARGX-113-2009 are listed below: 
• The end of part A of the study is defined as the date of the last visit of its last 
participant. 
• The end of part B of the study is defined as the date of the last visit of its last 
participant. 
• The end of the study is defined as the date of the last visit of the last participant in 
part B of the study. Alternatively, it is defined as the date of the last participant visit 
following the sponsor’s decision to terminate the study for any reason. 
A participant is considered to have completed the study under either of the following scenarios: 
• The participant completes the EoTP visit at week 36 and chooses to immediately 
enroll in the OLE study ARGX-113-2010. The moment that a participant decides to 
roll over to the OLE study, they are considered to have completed ARGX-113-2009. 
• The participant chooses not to enroll in the OLE study after completing the EoTP 
visit at week 36 and instead completes the 7-week treatment-free follow-up period 
(through week 43). 
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5. 
STUDY POPULATION 
Prospective approvals of protocol deviations to recruitment and enrollment criteria, also known 
as protocol waivers or exemptions, are not permitted. 
5.1. 
Inclusion Criteria 
Participants can be included in the study only if all of the following criteria apply: 
1. The participant is willing and able to do the following: 
a. understand the requirements of the study 
b. provide written informed consent (including consent for the use and disclosure 
of research-related health information) 
c. comply with the study protocol procedures (including required study visits). 
2B. The participant is male or female and has reached the local legal age of consent at the 
time of signing the informed consent form (ICF). 
3. The participants have clinical signs of BP (ie, presence of bullae), with or without the 
presence of urticarial/eczematous/erythematous plaques or pruritus at the screening 
and baseline visits. The diagnosis of BP must be confirmed by positive histopathology 
and DIF before randomization to treatment assignment, and by positive serology (by IIF, 
CLEIA, or ELISA, according to local practice) at screening (Section 8.1.2). 
4. The participant has an IGA-BP score of 3 or 4 at screening and baseline. 
5. The participant has a Karnofsky performance status of at least 60% at screening. 
6B. The participant agrees to use contraceptive measures consistent with local regulations and 
the following: 
a. Male participants (contraceptive measures provided in Section 10.4.2.2) 
b. WOCBP (defined in Section 10.4.1) must have a negative serum pregnancy test at 
screening and a negative urine pregnancy test at baseline before receiving IMP. 
(Section 10.4.2.1) 
5.2. 
Exclusion Criteria 
Participants are excluded from the study if any of the following criteria apply: 
1. Other forms of pemphigoid (including but not limited to pemphigoid gestationis, 
drug-induced BP that resolves after culprit-drug withdrawal, anti-p200 pemphigoid, 
mucous membrane pemphigoid, and cicatricial pemphigoid), or other AIBDs (including 
but not limited to epidermolysis bullosa acquisita, pemphigus vulgaris, and exfoliative 
erythroderma) 
2. Received unstable dose of treatments known to cause or exacerbate BP (eg, angiotensin 
converting enzyme inhibitors, penicillamine, furosemide, phenacetin, dipeptidyl 
peptidase 4 inhibitor) for at least 4 weeks prior the baseline visit 
3B. Use of BP treatments other than OCS, such as TCS, conventional immunosuppressants 
(eg, azathioprine, cyclophosphamide, methotrexate, mycophenolate mofetil), or dapsone, 
including the following: 
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a. sulfasalazine, IVIg, subcutaneous administration of immunoglobulin (SCIg), 
immunoadsorption or plasma exchange within 8 weeks of the baseline visit 
b. tetracyclines with or without nicotinamide at doses higher than the recommended 
daily allowance (RDA)/dietary reference intake (DRI) within 2 weeks of the baseline 
visit 
c. any monoclonal antibody (including rituximab or another anti-CD20 biologic) within 
6 months of the baseline visit 
d. complementary therapies—such as traditional Chinese medicines, herbs, or 
procedures (eg, acupuncture)—within 4 weeks (or 5 half-lives) of the baseline visit, 
if the investigator determines that such therapies may interfere with the study’s 
efficacy assessments and/or potentially risk the safety of the participant 
4. Known contraindication to OCS therapy 
5C. Clinically significant active infection that is not sufficiently resolved before baseline in 
the investigator’s opinion 
6A. Positive COVID-19 test result at screening (testing performed if required per local 
regulations) 
7A. Any other known autoimmune disease or any medical condition that, in the opinion of the 
investigator, would interfere with an accurate assessment of clinical symptoms of BP, 
prevent participants from complying with protocol requirements, or put the participant at 
undue risk 
8. History of malignancy unless deemed cured by adequate treatment with no evidence of 
recurrence for ≥3 years before the first administration of the IMP. Participants with the 
following cancers can be included at any time, provided they are adequately treated 
before their participation in the study: 
a. Basal cell or squamous cell skin cancer 
b. Carcinoma in situ of the cervix 
c. Carcinoma in situ of the breast 
d. Incidental histological finding of prostate cancer (tumor-node metastasis [TNM] 
stage T1a or T1b) 
9. Clinical evidence of other significant serious diseases, have had a recent surgery, or who 
have any other condition that, in the opinion of the investigator, could confound the 
results of the study or put the patient at undue risk 
10. Use of an investigational product within 3 months or 5 half-lives (whichever is longer) 
before the first dose of IMP 
11. Previously participated in a clinical study with efgartigimod 
12. Known hypersensitivity to any of the components of the administered treatments 
13A. Positive serum test at screening for an active infection with any of the following 
conditions: 
a. HBV that is indicative of an acute or chronic infection, unless associated with a 
negative hBsAg or negative HBV DNA test38 
b. HCV based on HCV antibody assay unless a negative RNA test is available 
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c. HIV based on test results that are associated with an AIDS-defining condition or a 
CD4 count <200 cells/mm3 
d. HIV based on test results of a CD4 count 200 cells/mm3 not adequately treated with 
antiviral therapy 
14A. Total IgG serum levels <4 g/L at screening. 
15A. Current or history (ie, within 12 months of screening) of alcohol, drug, or medication 
abuse as assessed by the investigator 
16A. Pregnant or lactating females and those who intend to become pregnant during the study 
17. Live or live-attenuated vaccine received <4 weeks before baseline visit 
18. Current participation in another interventional clinical study 
19. Severe renal impairment (creatine clearance <30 mL/min/1.73 m2) at screening 
5.3. 
Lifestyle Considerations 
Participants will not be required to restrict or limit any of their normal lifestyle activities 
(eg, food and drink consumption; caffeine, tobacco, or alcohol consumption; exercise or physical 
activity) during this study. 
5.4. 
Screen Failures 
A screen failure occurs when a participant who has signed the ICF is not assigned to IMP. A 
minimal set of screen failure information (demography, screen failure details, eligibility criteria, 
SAE reports) is required to ensure transparent reporting of screen failure participants and address 
regulatory authority queries. 
• Retesting: Participants with exclusionary clinical laboratory results, ECGs, vital sign 
measurements, etc that are inconsistent with their medical history or clinical 
evaluation, can be retested once within the remaining screening period to confirm the 
test value(s). 
• Rescreening: Participants who do not initially meet this study’s eligibility criteria can 
be rescreened once. For example, a participant who does not meet eligibility criteria 
because of an acute illness ongoing during screening (considering the illness itself 
does not violate inclusion/exclusion criteria), they can be rescreened once the illness 
is resolved or the medical issue stabilized. Rescreened participants will be 
reconsented and assigned a new participant number for the rescreening event. 
5.5. 
Criteria for Temporarily Delaying Study Participation 
As described in exclusion criterion 3B, participants with BP who have been treated with any of 
the following will be excluded from study participation: 
• Sulfasalazine, IVIg, SCIg, immunoadsorption, or plasma exchange within 8 weeks 
of the baseline visit 
• Tetracyclines (with nicotinamide [at doses higher than the RDA/DRI] or without 
nicotinamide) within 2 weeks of the baseline visit 
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• Any monoclonal antibody (including rituximab or another anti-CD20 biologic) within 
6 months of the baseline visit 
However, any potential ARGX-113-2009 candidate who has been treated with any 
of the above-noted therapies and still wishes to participate in the study must complete a wash-out 
period before they can be randomized to IMP. The duration of the required wash-out period must 
match the duration identified above for each class of medication. Note: therapy with TCS and/or 
conventional immunosuppressants (eg, azathioprine, cyclophosphamide, methotrexate, 
mycophenolate mofetil) or with dapsone requires no wash-out period; however, these therapies 
must be discontinued before baseline. 
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Table 6: 
Study Arm(s) 
BP=bullous pemphigoid; efgartigimod PH20 SC=efgartigimod for SC administration coformulated with rHuPH20; 
IMP=investigational medicinal product; OCS=oral corticosteroid (prednisone or equivalent); placebo=placebo for 
SC administration coformulated with rHuPH20; rHuPH20=recombinant human hyaluronidase PH20; 
SC=subcutaneous(ly) 
6.2. 
Preparation, Handling, Storage, and Accountability 
Details about the use of concurrent oral prednisone (or equivalent OCS) are described 
in Section 6.8.1. 
6.2.1. 
Preparation 
Efgartigimod PH20 SC will be provided as a sterile, clear to opalescent, colorless to yellowish 
solution for SC injection in masked glass vials. 
Placebo will be provided as a sterile, colorless, clear solution for injection in masked glass vials. 
These vials will contain the same formulation as the efgartigimod PH20 SC solution for 
injection, but without the active ingredient (efgartigimod). 
Trained and authorized study staff will use an amber colored syringe for preparation 
and administration of IMP; refer to Section 6.3 for details. 
The IMP will be manufactured in accordance with Good Manufacturing Practice (GMP) 
regulations. 
Arm Title 
Efgartigimod PH20 SC 
Placebo 
Arm Type 
Experimental 
Placebo 
Arm Description 
Participants will receive efgartigimod 
PH20 SC 
 mg (via  separate 
1000 mg SC injections) on day 1 
and day 8 
Participants will receive placebo (via  
separate SC injections) on day 1 and day 8 
 
Beginning at week 2, participants will 
receive efgartigimod PH20 SC 1000 mg 
(via single SC injection) once weekly 
through week 35. 
Beginning at week 2, participants will 
receive placebo (via single SC injection) 
once weekly through week 35. 
 
Participants will be administered 
concurrent OCS (oral prednisone) at 0.5 
mg/kg/day, or equivalent OCS) beginning 
at baseline (week 0); this dosage will be 
adjusted throughout the study based on the 
participant’s current BP disease status. 
Participants will be administered 
concurrent OCS (oral prednisone) at 0.5 
mg/kg/day (or equivalent OCS) beginning 
at baseline (week 0); this dosage will be 
adjusted throughout the study based on the 
participant’s current BP disease status. 
Associated Labels 
Efgartigimod PH20 SC 
OCS  
Placebo 
OCS  
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Detailed instructions for IMP management at the study site are included in the pharmacy manual. 
Instructions on the preparation and administration of IMP (including the volume of IMP 
to be administered) will be included in the on-site guide and the home administration guide. 
6.2.2. 
Handling 
The investigator or designee must confirm that appropriate temperature conditions have been 
maintained during transit for all IMP that has been received. Any discrepancies are reported 
and resolved before the use of any IMP. 
Participants who will be administered IMP during home visits (Table 1) will be given IMP 
to take home with them at their preceding on-site visit. Participants will be responsible for 
the correct handling of IMP and will return any used and unused portion back to the study site 
at their next on-site visit. In the event that COVID-19 pandemic travel/lockdown restrictions 
are in effect or on-site visits pose a potential risk to participants or site staff, IMP will be shipped 
to participants per courier. 
Only ARGX-113-2009 participants may receive IMP. Participants and/or their caregivers will 
be invited to receive training for (self-)administration of the IMP. In this study, participants 
(and/or their caregivers) will only be permitted to (self-)administer IMP at on-site visits under 
the supervision of site staff, and only after they have completed training and are determined 
competent enough to do so by site staff. During home visits, IMP may only be administered 
by a trained and authorized home nurse. 
6.2.3. 
Storage 
Both efgartigimod PH20 SC and placebo will be supplied to the pharmacy or dedicated site 
location at the study site by and under the responsibility of the sponsor’s designated IMP supply 
vendor. For each IMP batch at the site, the investigator will receive the certificate of analysis, 
certificate of conformity, and European Union qualified person release documents. 
All IMP must be stored in a secure, environmentally controlled, and monitored (via manual 
or automated system) area in accordance with the labeled storage conditions with access limited 
to the investigator and authorized site staff. Detailed instructions are included in the pharmacy 
manual. 
The IMP must be stored refrigerated (2°C to 8°C [36°F to 46°F]) in its secondary packaging, 
should not be exposed to freezing temperatures, should not be shaken, and should be protected 
from direct sunlight during storage at the investigative site. 
The investigator (or designee) is responsible for the correct and safe storage of the IMP assigned 
to the investigative site, in a locked, secure storage facility with access limited to those 
individuals authorized to dispense the IMP and maintained within the appropriate temperature 
ranges. 
For home administration, the participant is responsible for the correct storage of IMP. 
Detailed instructions on accountability for the IMP will be included in the pharmacy manual. 
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6.2.4. 
Accountability 
The investigator, institution, or the head of the medical institution (where applicable) is 
responsible for IMP accountability, reconciliation, and record maintenance (ie, receipt, 
reconciliation, and final disposition records). 
All used and unused IMP should be returned to the investigator at each dispensing visit. 
Additional guidance and information for the final disposition of used and unused IMP 
are provided in the pharmacy manual. 
6.2.5. 
Packaging and Labeling 
Packaging and labeling information is presented in Table 5. Additional information is included 
in the pharmacy manual. 
6.3. 
Measures to Minimize Bias: Randomization and Blinding 
The site will enroll the participant and a unique participant ID will be automatically allocated 
through interactive response technology (IRT) at the first screening visit. 
The results of all screening procedures have to be available before baseline (week 0) to 
determine the eligibility for entering the study. Randomization should be performed as soon as 
the participants meet the appropriate criteria to begin treatment. 
Upon confirmation of eligibility at baseline (week 0), the participant will be randomized through 
IRT. Participants will be randomized in a 1:1 ratio to receive efgartigimod PH20 SC or placebo. 
At randomization, part B participants will be stratified by region (China, Japan, rest of the 
world). Participants who comprise the “rest of the world” stratum will be further stratified by 
disease history (newly diagnosed or relapsing) and disease severity (severe [IGA‑BP score of 4] 
or moderate [IGA‑BP score of 3]). 
Because this is a randomized, double-blinded study, access to the IMP treatment assigned will 
be limited. No study team members from the investigating staff, sponsor staff who are directly 
involved in study management, or sponsor designees (except for staff at specialized laboratories 
who are responsible for PK, PD, and ADA analysis) will have access to the information related 
to IMP treatment assigned until after database lock. 
Efgartigimod PH20 SC is a colorless to yellowish solution, while placebo is a colorless solution. 
To ensure that participants and site staff remain blinded to IMP, both efgartigimod PH20 SC 
and placebo will be provided in masked glass vials; additionally, amber-colored syringes will 
be used for the preparation and administration of IMP (Section 6.2.1). 
An independent unblinded data and safety monitoring board (DSMB), including an independent 
statistician, will review all unblinded safety data as specified in Section 10.1.5. 
6.3.1. 
Emergency Unblinding 
This is a double-blinded study. The IRT will be programmed with blind-breaking instructions. In 
case of an emergency, the investigator is solely responsible for determining if unblinding of the 
IMP assignment is necessary. Participant safety must always be the first consideration in making 
such a determination. If the investigator decides that unblinding is warranted, the investigator 
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can contact the sponsor before unblinding a participant’s IMP unless this could delay emergency 
treatment for the participant. If a participant’s IMP assignment has been unblinded, the sponsor 
must be notified within 24 hours of this occurrence. The date and reason for the unblinding must 
be recorded in the source documents. 
If the blind is broken by the investigator, then it may be broken only for the participant 
concerned, and the IMP treatment assignment should not be revealed to the study team members 
from the sponsor, nor from the sponsor’s designee, pharmacy staff, or other site staff. 
Once unblinded, IMP will be permanently discontinued (Section 7.1.1). 
6.4. 
Study Compliance 
Participants will receive IMP under medical supervision at the site. The date and time of each 
dose administered will be recorded in the source documents. 
Participant compliance with IMP administration at home will be assessed by direct questioning 
during the site visit and documented in the source documents and relevant forms. Deviation(s) 
from the prescribed dosage regimen will be recorded. 
For each injection, the start and end times (hour and minute) and details of any interruptions 
or premature discontinuation of each injection will be recorded on the eCRF. The start time will 
be when the syringe plunger begins to be pressed; the end time will be when the administration 
of the total volume of IMP is finished. [Note: For the baseline (week 0) and week 1 IMP 
injections, site staff must record the start and end times (and the details of any interruptions 
or premature discontinuation of injections) for each of the  injections of IMP administered 
to participants on those days.] 
The sponsor’s designee will review the pharmacy records at each investigative site, including the 
IMP accountability and dispensing records. The sponsor’s designee will compare the dispensing 
record and vials with the individual participant’s identifiers, kit number, and visit schedule to 
confirm that the participant received the correct treatment and dose, and that the dosing schedule 
is correct. 
Errors that are identified will be discussed with site staff to ensure they are not repeated. 
The sponsor designee’s report will include details of any missed doses, errors in dose, treatment 
or scheduling errors, and the associated explanations. The sponsor will determine whether these 
dosing errors will be reported as protocol deviations in the clinical database. All supplies and 
pharmacy documentation must be made available throughout the study for the sponsor designee 
to review. 
The investigator should promote treatment compliance by stating that compliance is necessary 
for the participant’s safety and the validity of the study. The prescribed dose, timing, and mode 
of administration cannot be changed. Any deviations from the intended regimen must be 
recorded on the eCRF. 
Training for (self-) administration of IMP 
Participants and/or their caregivers will be invited to receive training for (self-)administration 
of the IMP. In this study, participants (and/or their caregivers) will only be permitted to 
(self-)administer IMP at on-site visits under the supervision of site staff, and only after they have 
completed training and are determined competent enough to do so by site staff. The IMP doses at 
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baseline (week 0) and week 1 must be administered by the investigator or designee under 
medical supervision. Starting at week 2, participants or caregivers can choose to be trained in 
IMP (self-)administration. Note that successful completion of this training is intended to enable 
self-administration or caregiver-supported administration at home in the OLE study 
ARGX-113-2010. 
6.4.1. 
Handling Missed Doses of the IMP 
All efforts will be made to ensure that the participant receives all administrations of IMP 
on the days scheduled (within the allowed visit windows). 
Incidents of missed IMP doses will be recorded on the eCRF, along with the reason(s) why 
the dose was missed. These reasons will be assessed by the investigator, site staff, and sponsor, 
who will agree upon and implement an appropriate set of actions to minimize the possibility 
of subsequent missed IMP doses. 
Participants who meet either of the following conditions will be excluded from the per-protocol 
analysis set: 
− Participants who miss a cumulative total of >50% of their scheduled doses of IMP 
− Participants who miss 3 or more consecutive scheduled doses of IMP 
6.4.2. 
Protocol Deviations 
The investigator should not implement any deviation from or changes to the approved protocol. 
Additionally, the investigator should not implement any deviation from or changes to the 
approved protocol before such deviations/changes are reviewed and approved by the Institutional 
Review Board/Independent Ethics Committee (IRB/IEC) and regulatory authority per local 
regulation. Exceptions will be permitted in cases of immediate hazard to study participants or 
when the change involves only logistical or administrative aspects of the study (eg, changes in 
contact information). The investigator (or designee) should document and explain any deviation 
from the approved protocol. 
6.5. 
Dose Modification 
Dose modifications are not permitted. 
6.6. 
Continued Access to IMP After the End of the Study 
Participants who reach the EoTP visit (week 36) may be offered the option to roll over into a 
long-term, OLE study (ARGX-113-2010). 
Participants will not be eligible to roll over into the OLE study if they discontinue from study 
ARGX-113-2009 (eg, withdrawal of consent). Participants who are eligible but choose not to roll 
over into the OLE study ARGX-113-2010 will complete a 7-week treatment-free follow-up 
period. 
If a participant permanently withdraws from the study or is permanently withdrawn from 
the study by the investigator (Section 7.2), standard-of-care BP treatment may be administered 
by the participant’s primary care physician. 
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6.7. 
Treatment of Overdose 
For this study, a variation of more than 10% of the intended weekly amount of IMP will be 
considered an overdose. 
An overdose is defined as a deliberate or accidental administration of IMP to a participant, 
at a dose greater than that assigned to that participant per the study protocol. 
In the event of an overdose, the investigator should: 
• Contact the medical monitor immediately. 
• Evaluate the participant to determine, in consultation with the medical monitor, whether 
IMP should be interrupted or whether the dose should be reduced. 
• Closely monitor the participant for any AE/SAE and laboratory abnormalities. 
• Document the quantity of the excess dose and the duration of the overdose on the eCRF. 
6.8. 
Concomitant Therapy 
Participants must maintain a stable regimen of medications throughout the study. Any 
medication or vaccine (including over-the-counter or prescription medicines, recreational drugs, 
vitamins, and/or herbal supplements [including Chinese traditional medicine]) or other specific 
categories of interest that the participant is receiving at screening or receives during the study 
must be recorded on the eCRF along with: 
• Reason for use 
• Dates of administration, including start and end dates 
• Dosage information including dose and frequency 
• Brand name (for vaccines only) 
All available vaccination history should be recorded as part of the participant’s prior medication 
for vaccinations received in the past, or as concomitant medication for vaccinations received 
during the study, as described in the SoA (Table 1). Any vaccination information that the 
participant, or their caregiver can remember should be recorded on the eCRF (with the brand 
name of the vaccine and date of vaccination, if possible). 
The medical monitor should be contacted if there are any questions regarding concomitant 
or prior therapy. 
6.8.1. 
Concurrent Bullous Pemphigoid Therapy – Oral Prednisone 
All participants, regardless of study IMP assignment, will also receive concurrent therapy with 
OCS, ie, prednisone at a starting dosage of 0.5 mg/kg/day at baseline (week 0), or an alternate 
OCS at an equivalent dose strength. The OCS dosage will be adjusted according to each 
participant’s BP disease status throughout the study, with the goal of rapidly tapering systemic 
corticosteroid exposure and preventing and/or treating relapse. The oral prednisone dose 
adjustment procedure is described in Section 6.8.1.3. 
If the investigator considers it necessary, oral prednisone ≤0.3 mg/kg/day (or equivalent OCS) 
may be administered to participants during the period between their screening and baseline visits. 
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6.8.1.1. 
General Oral Prednisone Information 
Information on the formulation, unit dose strength, sourcing, packaging, and labeling of oral 
prednisone is summarized in Table 5. 
Investigators, study site staff, and participants must comply with package labeling instructions 
for proper oral prednisone storage and handling. 
During each on-site visit, study site staff will provide the participant with a supply of daily oral 
prednisone doses (or equivalent OCS) sufficient to last until the participant’s next on-site visit. 
Participants will return any used and unused doses to the study site at their next on-site visit. 
6.8.1.2. 
Oral Prednisone Dosing and Treatment Compliance 
Participants will take oral prednisone (or equivalent OCS) daily at the dose directed 
by the investigator. 
Participants will be provided a diary to record daily intake of each oral prednisone dose. 
The participant will bring their completed diary with them to every on-site visit so that staff 
can review the dosing record; during home visits, the participant will share their diary 
information with site staff. 
If a participant misses one or more oral prednisone doses, they must contact the investigator. 
The missed doses must not be “made up”; rather, the participant will resume taking the daily oral 
prednisone dosage prescribed by the investigator, unless they have had a change in BP disease 
status that warrants dose adjustment (Section 6.8.1.3). 
6.8.1.3. 
Oral Prednisone Dose Adjustment Regimen (Based on BP Disease Assessment) 
Participants will receive IMP with concurrent OCS therapy. The recommended OCS dosing 
regimen is described below and displayed in Table 7. 
The investigator should not deviate from the concurrent oral prednisone dosing regimen, except 
in matters where the safety of the participant may be compromised. After taking appropriate 
action to ensure the safety of the participants, such concerns should be documented and 
communicated to the sponsor’s medical monitor and designee within 24 hours of the event. 
For OCS doses not listed in Table 7, minimum and maximum recommended doses are provided. 
For participants with body weights of <45 kg or ≥110 kg, the investigator should propose OCS 
doses and inform the medical monitor to ensure consistency within the study. 
Note: For the following list, “oral prednisone” refers to prednisone or an alternate OCS 
of equivalent dose strength. 
• All participants will begin the study by taking oral prednisone 0.5 mg/kg/day starting 
at baseline (week 0; day 1). 
• If the participant has not achieved CDA within 1-3 weeks of treatment with oral 
prednisone 0.5 mg/kg/day, then the dosage may be increased to 0.75 mg/kg/day 
for up to an additional 3 weeks. This period may be extended by 1 additional week 
(based on clinical judgment) to achieve CDA with an oral prednisone dosage of either 
0.75 mg/kg/day or 1 mg/kg/day. 
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• A participant will be considered as a treatment failure if they do not achieve CDA 
after receiving the IMP with the prednisone dosing regimen described above. In case 
of treatment failure, IMP will be permanently discontinued (Section 7.1.1). Under 
these circumstances, the participant will be considered a nonresponder 
(Section 9.3.2). 
• When CDA is achieved, the oral prednisone dosing regimen is adjusted as follows: 
− After CDA has been sustained for ≥2 weeks, the dose tapering schedule begins 
with the next lower oral prednisone dosage as listed in Table 7. Each new dosage 
must be maintained for at least 2 weeks provided that no new lesions (transient or 
nontransient) appear. Duration of tapering steps from escalated doses 
(>0.5 mg/kg/day) may be shortened based on clinical judgment. 
− For participants who achieved CDA on oral prednisone 0.5 mg/kg/day, the 
tapering steps are 0.3, 0.2, 0.15, and 0.1 mg/kg/day. For participants who required 
a dose increase to 0.75 or 1.0 mg/kg/day to achieve CDA, the oral prednisone 
dosage must first be tapered down to 0.5 mg/kg/day before proceeding to 0.3, 0.2, 
0.15, and 0.1 mg/kg/day as shown in Table 7. 
− Further tapering below the level of minimal OCS therapy can be performed 
in steps of 2.5 mg/day until the participant is off oral prednisone therapy 
(Table 7). Each new dosage step must be maintained for at least 2 weeks, 
provided that no new lesions (transient or nontransient) appear. 
− If a participant has new lesions after the start of OCS tapering (ie, after CDA has 
been sustained for ≥2 weeks) but the investigator determines that it is not a 
relapse, prednisone tapering will be delayed. Under these circumstances, tapering 
can resume when no new lesions have appeared for at least 1 week (Table 7). 
• If a participant relapses: 
− The oral prednisone dosage is increased based on the clinical judgment of the 
investigator, with the recommendation to return to the dose administered 2 
tapering steps before the relapse. Tapering can be resumed after CDA has been 
sustained for at least 2 weeks on this increased dose. 
− If CDA is not achieved, the participant should resume the initial oral prednisone 
dosage of 0.5 mg/kg/day. 
− The participant must resume weekly on-site visits until CDA returns. 
For concurrent oral methylprednisolone equivalent doses, refer to Table 16. 
For home study visits that occur between mandatory on-site visits, the investigator will call 
the participant once weekly to review the participant’s BP disease status and current oral 
prednisone (or equivalent) dosing regimen (Section 8.1.4). 
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a Body weight should be rounded to the nearest whole number. 
b The investigator should not deviate from the concurrent oral prednisone dosing regimen as specified in the table, except in matters where the safety of the 
participant may be compromised.
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6.8.2. 
Prohibited Medications and Therapy During the Study 
The following medications or treatments are not permitted while the participant receives IMP: 
• Any systemic treatment for BP (except concurrent OCS), including but not limited to 
immunosuppressants, IVIg, SCIg, immunoadsorption, anti-CD20 biologics, 
tetracyclines with or without nicotinamide, dapsone, and IV or IM corticosteroids 
• TCS (use must be discontinued before baseline) 
• Any other biologic agent or experimental/study IMP 
• Live or live-attenuated vaccines 
• Complementary therapies, including traditional Chinese medicines, herbs, or 
procedures (eg, acupuncture), as assessed by the investigator 
As discussed in Section 6.8.3, some of these treatments can be administered as rescue therapy 
if the participant discontinues IMP. 
6.8.3. 
Rescue Therapy 
Participants will discontinue IMP and may start rescue therapy if any of the following occur: 
• The participant fails treatment with IMP (defined in Section 4.1.3) 
• The participant relapses twice 
• The participant presents with steroid toxicity (or any severe AE determined by the 
investigator to be related to OCS therapy) 
Participants reporting any of the events mentioned above will permanently discontinue IMP 
(Section 7.1.1). 
Rescue therapy may include OCS, TCS, conventional immunosuppressants (eg, azathioprine, 
cyclophosphamide, methotrexate, mycophenolate mofetil), tetracyclines with or without 
nicotinamide, dapsone, or IVIg. As described in Section 6.8.2, these treatments are permitted as 
rescue therapy following discontinuation of IMP. 
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7. 
IMP DISCONTINUATION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL 
Discontinuation of specific sites or the entire study is described in Appendix 1 (Section 10.1.11). 
7.1. 
IMP Discontinuation 
7.1.1. 
Permanent Discontinuation 
Permanent discontinuation of IMP occurs when the participant stops receiving IMP before the 
end of the study, and does not resume receiving IMP. The participant also must not have 
withdrawn informed consent. 
The investigator will document the primary reason for early discontinuation of IMP. 
Participants who permanently discontinue IMP will be encouraged to remain in the study and 
attend mandatory on-site visits as specified in the SoA (Table 1). If the participant cannot attend 
these visits for any reason, the study site will perform an early study discontinuation (ESD) visit 
and safety follow-up visits as specified in the SoA (Table 1). 
Unless consent from the study has been withdrawn, the participant will attend an early treatment 
discontinuation (ETD) visit. Study sites will attempt to perform the ETD visit within 7 days after 
the participant’s final IMP administration. After the ETD, the participant will continue 
participation in the study through the rest of the 36-week treatment period and may receive 
rescue therapy (defined in Section 6.8.3). At week 36, the participant will complete the EoTP 
visit assessments (Table 1). If the participant meets rollover eligibility requirements (described in 
the ARGX-113-2010 protocol) at the end of the EoTP visit, they will be invited to immediately 
enroll in the OLE study ARGX-113-2010. If the participant does not meet rollover eligibility 
requirements or chooses not to enroll in the OLE study, they will participate in the 7-week 
treatment-free follow-up period. Refer to the SoA (Table 1) for data to be collected at the time of 
discontinuation of IMP and follow-up and for any other evaluations that need to be completed. 
The following circumstances will result in the permanent discontinuation of IMP: 
• Participant becomes pregnant or intends to become pregnant (refer to Section 8.4.6). 
• Investigator decides that discontinuing IMP is in the participant’s best interest (the 
sponsor will be informed). 
• Participant develops an SAE or AE that contraindicates further administration of IMP 
in the investigator’s opinion. 
• Unblinding occurred. 
• Participant exhibits any of the conditions outlined in Section 6.8.3. In these cases, 
participant may start rescue therapy. 
• Any of the liver chemistry criteria resulting in temporary IMP discontinuation 
outlined in Section 7.1.2 is met, and the event is considered by the investigator to be 
related to the IMP. 
• The participant develops any of the following, based on the sponsor’s determination 
of relatedness: 
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− Any treatment-emergent adverse event (TEAE) of Common Terminology Criteria 
for Adverse Events (CTCAE) severity grade 4 that is considered related to IMP 
− Any treatment-emergent SAE of grade 3 considered related to IMP 
− Any infections of grade 3 or any serious infection considered related to IMP 
• The participant develops any malignancy, either new or recurrent, other than basal 
cell carcinoma of the skin, regardless of relatedness. 
7.1.2. 
Temporary Discontinuation 
Temporary discontinuation of IMP occurs when the participant discontinues receiving IMP 
before the end of the study and resumes once the cause for the discontinuation has been resolved. 
Reasons for temporary discontinuation may include an AE that meets the following criteria: 
• Any SAE considered related to IMP by the sponsor 
• Clinically significant active infection considered related to the IMP by the sponsor 
• Any of the following liver chemistry laboratory results: 
− Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) values 
>8 times the upper limit of its normal reference range (×ULN) 
− ALT or AST values >5×ULN sustained for more than 2 weeks 
− ALT or AST values >3×ULN plus total bilirubin >2×ULN 
− ALT or AST values >3×ULN plus international normalized ratio (INR) >1.5 
− ALT or AST values >3×ULN with the appearance of any of the following signs 
and symptoms of liver toxicity: 
o Fatigue 
o Nausea 
o Vomiting 
o Pain or tenderness in the upper-right quadrant of the abdomen 
o Fever 
o Rash 
o Eosinophilia (eosinophil count >5×108/L) 
Participants with any of these events will have the laboratory tests repeated within 
48 hours. These participants will also be evaluated to determine whether the cause of 
the liver enzyme elevation is a disease/condition other than toxicity related to IMP 
(eg, viral hepatitis, preexisting or acute liver disease, or toxicity related to 
concomitant medications other than IMP). If the event is considered by the 
investigator to be related to the IMP, IMP will be permanently discontinued 
(Section 7.1.1). 
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7.2. 
Participant Discontinuation/Withdrawal From the Study 
Study withdrawal is defined as the permanent cessation of further participation in any study 
assessment before its planned completion. 
The primary reason for permanent study withdrawal will be recorded. 
The following circumstances will result in permanent discontinuation and withdrawal from the 
study: 
• Participant withdrawal of consent 
• Sponsor request 
• Investigator request due to noncompliance with study protocol procedures 
If the participant withdraws consent to participate in the study, the sponsor can retain and 
continue to use any data collected before consent was withdrawn.  
Future research on samples collected from participants who withdraw consent to participate in 
the study will not be affected unless the participant also withdraws the consent for future 
research. 
If possible, an ESD visit should be conducted at the time the participant is withdrawn from the 
study (Table 1). Study sites should make every effort to perform the ESD visit within 7 days of 
the participant’s last IMP dose. At the conclusion of the ESD visit, the participant will be asked 
if they will participate in the 7-week treatment-free follow-up period. A comment must be added 
to the source records to note if the participant accepts or rejects to perform the ESD visit and/or 
the treatment-free follow-up period. If the participant chooses not to participate in the 
treatment-free follow-up period, they will be permanently discontinued from IMP and the study 
at that time. 
Participants withdrawn from the study will be ineligible to roll over to the OLE study 
(ARGX-113-2010). 
7.3. 
Lost to Follow-up 
A participant will be considered lost to follow-up if they repeatedly fail to return for scheduled 
visits and cannot be contacted by the study site. 
The following actions must be taken if a participant fails to return to the clinic for a required 
study visit: 
• The site must attempt to contact the participant and reschedule the missed visit as 
soon as possible, counsel the participant on the importance of maintaining the 
assigned visit schedule, and ascertain whether the participant wishes to and/or should 
continue in the study. 
• Before a participant is considered lost to follow-up, the investigator or designee must 
make every effort to regain contact with the participant (where possible, 3 phone 
calls, and if necessary, a certified letter to the participant’s last known mailing 
address or local equivalent methods). These contact attempts should be documented 
in the participant’s medical record. 
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• Should the participant continue to be unreachable, they will be considered to have 
withdrawn from the study. 
• Site staff, or an independent third party, will attempt to collect the vital status of the 
participant within legal and ethical boundaries for all participants randomized, 
including those who did not get IMP. Public sources may be searched for vital status 
information. If vital status is determined as deceased, this will be documented and the 
participant will not be considered lost to follow-up. Sponsor staff will not be involved 
in any attempts to collect vital status information. 
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8. 
STUDY ASSESSMENTS AND PROCEDURES 
General Note – COVID-19 Considerations: Operational considerations due to the COVID-19 
pandemic are provided in Section 10.14. The sponsor or the investigator may implement 
alternate strategies for participant visits, assessments, medication distribution, and monitoring 
resulting from COVID-19 concerns and/or restrictions per local health authority/ethics 
requirements. 
8.1. 
General Considerations 
8.1.1. 
General 
• Study procedures and their timing are summarized in the SoA (Table 1). Protocol 
waivers or exemptions are not allowed. 
• Adherence to the study design requirements, including those specified in the SoA, 
is essential and required for study conduct. 
• From signing of the ICF until the last study-related activity, all AEs, concomitant 
medications, and procedures must be recorded on the eCRF. 
• Safety/laboratory/analyte results that could unblind the study will not be reported 
to investigative sites or other blinded staff until the study has been unblinded. 
8.1.2. 
Screening Period 
• Screening eligibility assessments, including their timing and the duration of the 
screening period, are listed in the SoA (Table 1). Screening assessments can only be 
performed after the participant has provided informed consent (by signing the ICF). 
• All screening evaluations must be completed and reviewed before enrollment to 
confirm that potential participants meet all eligibility criteria. 
• The investigator will record the details of all participants who are screened for the 
study, and then confirm eligibility for each or record the reasons for screening failure, 
as applicable. 
• At screening, total IgG serum levels will always be measured in a central laboratory. 
The eligibility assessment can be based on central or local laboratory samples taken at 
screening or historical laboratory results from samples taken up to 7 days before 
screening (exclusion criterion 14A). 
• A serological confirmation of BP diagnosis must be available using a positive IIF, 
CLEIA, or ELISA result according to local practice (inclusion criterion 3). The 
presence of anti-BP180 and anti-BP230 antibodies will also always be evaluated 
centrally by ELISA. In case serology methods are not available locally, the central 
laboratory result will be used for assessment of eligibility. The eligibility assessment 
may also be based on historical laboratory results from local samples taken up to 
7 days before screening. 
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• The first day of the screening period is the day of the screening visit (the date of first 
screening visit is defined by the date of first screening procedure after signing the 
ICF). 
8.1.3. 
Treatment and Follow-Up Periods 
• Each participant should attend each study visit on the designated days (Table 1). 
There is a permissible visit window of ±2 days during the treatment period and 
±3 days during the treatment-free follow-up period. 
• Immediate safety concerns should be discussed with the sponsor immediately upon 
occurrence or awareness to determine if the participant should continue or 
discontinue IMP. Additionally, an independent unblinded DSMB may review all 
unblinded safety data on a regular basis as specified in Section 10.1.5. 
• Participants who received IMP throughout the entire the 36-week treatment period 
will complete the EoTP visit assessments (Table 1) at week 36. 
• Participants who discontinue IMP early will complete an ETD visit (Table 1), may 
begin rescue therapy (Section 6.8.3), continue their treatment period visits as 
scheduled, and then complete the EoTP assessments (Table 1) at week 36. 
• Participants who withdraw consent or are permanently discontinued from the study 
will complete an ESD visit (Table 1); details for the study discontinuation procedures 
are provided in Section 7.2. 
• Participants who complete the EoTP visit and choose not to enroll in the OLE study 
ARGX-113-2010 will complete the treatment-free follow-up period visits at weeks 39 
and 43 (Table 1). 
8.1.4. 
Home Study Visits 
For other weekly visits as indicated in the SoA (Table 1), a home nurse or qualified site staff 
may travel to the participant’s home to conduct visits or meet the participant at a convenient 
alternative location. Home nurse is either a nurse from the study site or a nurse from a 
commercial nursing vendor who is delegated by the investigator. 
For home study visits, the investigator will call the participant within 48 hours before IMP 
administration to elicit AEs and participant’s general well-being, and review the current BP 
disease status and OCS dosing regimen. The investigator will check with the participant if they 
have new lesions, transient or nontransient. If any new lesions are reported, the participant 
should visit the clinic for an unscheduled appointment (refer to Section 8.1.5). 
8.1.5. 
Unscheduled Visits 
In case of suspected new lesions as reported by the participant, or other issues requiring site staff 
intervention, such as notable weight changes, participants should come to the clinic for an 
unscheduled (UNS) visit for disease assessment. The investigator will decide which assessments 
to conduct based on the purpose of the unscheduled visit (Table 1). In case of relapse, IGA-BP, 
BPDAI, and Itch NRS assessments must be performed and participants should return to weekly 
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on-site visits until CDA is achieved again. At the UNS visits, blood samples for PK will only be 
collected if IMP is administered. 
8.2. 
Efficacy and Quality of Life Assessments 
Planned time points for all efficacy and QoL assessments are presented in the SoA (Table 1). 
8.2.1. 
Efficacy Assessments 
8.2.1.1. 
Assessment of BP Disease Status and OCS Dose Monitoring 
The efficacy of treatment will be assessed by the investigator, who will assess the BP disease 
status (CDA, PR, CR, relapse, treatment failure) of the participant according to the 
definitions/criteria presented in Section 4.1.3. The investigator will also record the daily OCS 
dose administered to the participant since the last visit, adjust the daily OCS dose (taper, stop, 
re-initiate, or increase) based on the participant’s BP disease status, and record treatment failures 
during on-site visits. For details on reviewing the current BP disease status and OCS dosing 
regimen for home study visits occurring between mandatory on-site visits, refer to Section 8.1.4. 
8.2.1.2. 
Investigator Global Assessment of Bullous Pemphigoid 
BP disease activity and severity will be assessed by the investigator using the IGA-BP 
(Section 10.6). The IGA-BP is a new assessment tool that was developed in 2021 by medical 
experts in the field of AIBDs, and it is currently being used (along with the BPDAI) in other 
clinical studies of therapies for BP. The IGA categorizes the severity of BP on a numerical scale 
of 0 (clear) to 4 (severe). 
8.2.1.3. 
Bullous Pemphigoid Disease Area Index 
In addition to the IGA-BP, BP disease activity will also be assessed by the investigator using 
the BPDAI2 (Section 10.7). The BPDAI is an internationally validated tool to objectively 
measure disease activity. The BPDAI differentiates scores for skin (erosions/blisters and 
urticaria/erythema) and mucous membrane activity in several anatomical locations. In addition, 
separate scores for damage (eg, pigmentation) are recorded to account for healing lesions.2,22 
8.2.1.4. 
Itch Numerical Rating Scale 
Pruritic symptoms of BP will be indicated by the participant on the Itch NRS (Section 10.8), 
recording an average and a worst score for itch suffered within the past 24 hours. 
8.2.2. 
Quality of Life (QoL) Assessments 
Participants will complete the following PRO assessments of their QoL at the time points listed 
in the SoA (Table 1): 
• EuroQol 5-dimension 5-level Scale (EQ-5D-5L; Section 10.9): the EQ-5D-5L 
is a standardized measure of health status developed by the EuroQol Group to provide 
a simple, generic measure of health for clinical and economic appraisal. 
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The descriptive system comprises 5 dimensions (mobility, self-care, usual activities, 
pain/discomfort, anxiety/depression). Each dimension now has 5 levels: no problems, 
slight problems, moderate problems, severe problems, and extreme problems. 
• Dermatology Life Quality Index (DLQI)36 (Section 10.10): the DLQI consists 
of 10 questions concerning the participant’s perception of the impact of skin diseases 
on different aspects of their health-related QoL the previous week. The impact of 
each aspect on the QoL assessment is scored qualitatively, ranging from “not at all” 
to “very much.” 
• Autoimmune Bullous Disease Quality of Life Index (ABQoL) questionnaire37 
(Section 10.11): the ABQoL was developed and validated for determining the impact 
of AIBDs and their therapies on the daily life of patients. It is a series of 17 questions 
concerning the participant’s perceptions of how AIBD is affecting their daily lives, 
including comfort, hygiene, eating/drinking, appearance, social interactions, sexual 
activity, and employment. 
8.3. 
Safety Assessments 
Planned time points for all safety assessments are provided in the SoA (Table 1). Safety 
measures will be assessed before IMP administration unless otherwise stated. 
8.3.1. 
Physical Examinations 
Physical examinations will be performed at the time points indicated in the SoA (Table 1). 
A physical examination will include, at a minimum, an assessment of general appearance, skin, 
head and neck (including ears, eyes, nose and throat), lymph nodes, thyroid, musculoskeletal 
condition, extremities, abdomen, breast, and cardiovascular, respiratory, neurological, and 
genital/rectal systems. Any signs related to the natural history of BP are not to be reported 
as physical abnormalities. 
Investigators should pay special attention to clinical signs related to previous serious illnesses. 
Abnormalities in physical examination at screening will be reported as medical history on the 
eCRF. At all other study visits, new clinically significant abnormal or worsened preexisting 
conditions will be reported as an AE. 
8.3.2. 
Height and Weight 
Height and weight will be measured at screening, and body mass index (BMI) will be calculated 
accordingly. Weight will be measured again at the time points indicated in the SoA (Table 1). 
Height and weight will also be measured without shoes, attired in light clothing. 
8.3.3. 
Vital Signs 
The assessment of vital signs (supine blood pressure, heart rate, and body temperature) will 
be performed at the time points indicated in the SoA (Table 1) and should be completed predose 
at visits when IMP is administered. 
Supine blood pressure and heart rate will be measured using standard equipment after at least 
10 minutes of rest. 
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It is recommended that the method used to measure the body temperature of the participant 
at screening (eg, orally, tympanic, rectal, axillary, skin, temporal) should be the same method 
used for the participant at both on-site and home visits throughout the study. 
Abnormalities in vital sign measurements at screening will be reported as medical history 
on the eCRF. At all other study visits, new clinically significant abnormal or worsened 
pre-existing vital sign abnormalities will be reported as an AE. 
8.3.4. 
Electrocardiograms 
ECGs will be performed at the time points indicated in the SoA (Table 1) and should be 
completed predose at visits when IMP is administered. 
ECGs will be performed according to instructions provided by a centralized ECG reading 
facility. At a minimum, interval data (PR, QT, QTcF, and QRS intervals), ventricular rate, and 
overall interpretation will be recorded for each ECG. 
Abnormalities in ECG at screening will be reported as medical history on the eCRF. At all other 
study visits, new clinically significant abnormal or worsened pre-existing ECG abnormalities 
will be reported as AEs. 
8.3.5. 
Medical and Surgical History 
All significant findings, surgeries, and pre-existing conditions (including allergies, if any) 
present at screening must be reported on the relevant medical history/current medical conditions 
page of the eCRF, including start and end dates, if known. 
Information should be provided on medical and surgical history and concomitant medical 
conditions specifying those ongoing at screening. 
Details collected as a part of the medical history must include, but are not limited to, all previous 
treatment/therapy taken for BP, including start and end dates, if known. 
All available vaccination history will be recorded as part of the participant’s prior medication 
for vaccinations received in the past, or concomitant medication for vaccinations received during 
the study as described in the SoA (Table 1). Any vaccination information the participant, or 
his/her caregiver can remember should be recorded on the eCRF (with the brand name of the 
vaccine and date of vaccination, if possible). 
8.3.6. 
Clinical Safety Laboratory Tests 
8.3.6.1. 
Standard Blood and Urine Laboratory Tests 
Blood and urine samples will be collected at the time points indicated in the SoA (Table 1) 
and analyzed at a laboratory for determination of clinical chemistry, hematology, coagulation, 
urinalysis, and serology (eg, viral marker testing); the parameters for each analysis are listed 
in Section 10.2. 
The investigator must review the laboratory report, document this review, and record any 
clinically significant changes occurring during the study as an AE. The laboratory reports must 
be filed with the source documents. 
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Abnormal laboratory findings associated with the underlying disease are not considered 
clinically significant unless considered by the investigator to be more severe than expected 
for the participant’s condition. 
The details of sample collection, handling, storage, and transportation of the samples will be 
described in the laboratory manual. 
All laboratory tests with values considered clinically significantly abnormal during participation 
in the study or within 60 days after the last dose of IMP should be repeated until the values 
return to normal or baseline or are no longer considered clinically significant by the investigator 
or medical monitor. 
• If such values do not return to normal/baseline within a period of time considered 
reasonable by the investigator, the etiology should be identified, and the sponsor 
notified. 
• All protocol-required laboratory tests (as defined in Section 10.2) must be conducted 
in accordance with the laboratory manual and the SoA (Table 1). 
• If laboratory values from non-protocol-specified laboratory tests performed 
at the institution’s local laboratory require a change in participant management 
or are considered clinically significant by the investigator (eg, AE or SAE), 
then the results must be recorded on the AE or SAE form. 
8.3.6.2. 
Substudy (at Selected Sites) – Vaccination Response 
Sites will collect all available vaccination history from study participants. 
Selected sites may collect additional blood samples for additional/optional/future vaccination 
research. Such research may include (but not be limited to) the following: 
1. Measurement of historical protective antibody titers in serum 
2. Humoral (serum) responses to vaccinations received during the study 
3. Cellular (peripheral blood mononuclear cells [PBMCs]) responses to vaccinations 
received during the study 
These samples will only be collected from participants who have provided additional consent 
for the procedure, at the visits identified in the SoA (Table 1). Note: if the 12- and 24-week 
postvaccination samples cannot be taken during the treatment period (Table 1), then 
a postvaccination sample can be taken at the last participation time point in this study 
(eg, the ESD or F2 visit) or in the OLE study (ARGX-113-2010), as applicable. 
Data obtained from this substudy will not be included in the clinical database; the results may 
be described in a separate report. 
8.3.6.3. 
Use and Storage of Blood Samples 
Blood samples that are collected at the screening visit may be used to validate methods 
to measure efgartigimod, antibodies, and biomarkers. Participants must consent to having their 
samples used in this manner before such procedures are performed. 
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Any samples remaining after the laboratory analyses as defined in the protocol have been 
completed may be stored for up to 15 years after the end of the study, in the laboratory 
or long-term storage designated by the sponsor or research partners worldwide, for future 
additional medical, academic, or scientific research to address any scientific questions related 
to efgartigimod, FcRn biology, or BP, unless this would not be allowed according to local 
regulations or the participant would not have agreed. 
8.3.7. 
Infections and Vaccinations 
Patients with BP are susceptible to developing opportunistic infections. Concomitant and 
historical treatments by immunosuppressive or immunomodulatory therapies are comorbidity 
factors able to trigger or aggravate these infections. 
In this study, some measures able to mitigate the occurrence of infections are required, and other 
precautionary measures optimizing the prevention of infections are recommended. For these 
reasons, the following actions are excluded for study entry: 
• The administration of live or live-attenuated vaccines (eg, measles, mumps, rubella, 
rotavirus, smallpox, chickenpox, yellow fever) within the 4-week period before 
baseline visit or during the study (Section 6.8.2). 
• Participants with a clinically significant active infection that is not sufficiently 
resolved before baseline in the investigator’s opinion (exclusion criterion 5C). 
• Participants who tested positive for an active viral infection at screening with HBV, 
HCV, and HIV (exclusion criterion 13A). 
• Participants with total IgG serum levels <4 g/L at screening (exclusion criterion 14A). 
The following measures are highly recommended before and during the study: 
• To initiate or renew administration of non-live, inactivated, polysaccharide or 
recombinant vaccines (eg, tetanus, hepatitis A, hepatitis B, shingles) in participants 
susceptible to enter the study, at least 4 weeks before baseline visit. 
• To vaccinate participants who are especially prone to or with an history of respiratory 
infections against Pneumococcus or Streptococcus pneumoniae. 
• To vaccinate participants with seasonal vaccines (eg, influenza virus), especially 
those susceptible to enter the study in the winter months. 
• To screen for possible infections (eg, respiratory, skin, mouth, eyes, nose and throat, 
genitals) and, if appropriate, initiate antibiotic treatment before baseline visit. 
• To provide participants suffering from recurrent episodes of herpes simplex or herpes 
zoster with antiviral treatment throughout the treatment period of the study. 
Any inactivated, subunit, polysaccharide, or conjugate vaccine will be allowed at the discretion 
of the investigator and if it is administered at least 48 hours predose or 48 hours postdose 
of the IMP. 
Any other preventive measure that may be considered for the safety of the participants can also 
be discussed on a case-by-case basis with the sponsor’s medical monitor and designee before 
the participant enters the study. 
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All available vaccination history and any vaccination received during the study should be 
recorded on the eCRF with the brand name of the vaccine and the date of vaccine administration. 
8.3.8. 
Pregnancy Testing 
• WOCBP (Section 10.4.1) will be tested for pregnancy by serum at screening. Urine tests 
for pregnancy will occur at the time points specified in the SoA (Section 1.3). 
• Pregnancy testing in WOCBP will be conducted at the end of relevant systemic exposure 
(ie, at the safety follow-up visits). 
• Additional pregnancy testing may be performed as necessary by the investigator or as 
required by local regulations, to establish the absence of pregnancy at any time during the 
study. 
• Any pregnancy reported during a clinical research study, including the safety follow-up 
period, is routinely monitored as standard practice. The pregnancy could have arisen from 
a female clinical study participant or a male participant's female partner. In either 
situation, consent will be requested to collect medical information about the pregnancy 
and the baby's health for up to 12 months after the baby’s birth. 
8.3.9. 
Additional Safety Assessment – the Glucocorticoid Toxicity Index 
As an additional assessment of the impact of glucocorticoid morbidity, the GTI v2.0 will be 
assessed at the visits listed in the SoA (Table 1). The GTI v2.0 is a complementary scoring 
system to the overall report of AEs that are considered related to glucocorticoids by investigators 
during interventional studies. It also enables the monitoring of long-term tolerability of 
glucocorticoids during their prolonged use during clinical practice.39 
The GTI v2.0 consists of the following 2 instruments: 
• The Composite-GTI (C-GTI), which serves as a primary instrument intended to capture 
toxicities that are likely due to glucocorticoid exposure. The C-GTI has 9 functional 
domains: BMI, glucose control, blood pressure, lipid metabolism, bone mineral density, 
muscle strength, skin toxicity, neuropsychiatric effects, and infection. Each domain 
includes several weighted items that correspond to varying degrees of glucocorticoid 
toxicity. 
Note: the bone mineral density domain will not be used in this study, because it is 
typically excluded from studies <1 year in duration, because bone densitometry is not 
sufficiently reliable in measuring changes over shorter durations.39 
Two analytical scores are generated from the weighted C-GTI items: the Cumulative 
Worsening Score (CWS) and the AIS. The CWS is designed to assess cumulative 
glucocorticoid toxicity, while the AIS can be used to assess whether a new therapy is 
effective in reducing glucocorticoid toxicity over time. Together, the CWS and AIS 
provide complementary information about the ability of an investigational agent to 
reduce overall glucocorticoid toxicity. 
• The Specific List of the GTI (GTI-SL) captures well-known glucocorticoid-related side 
effects. This non-weighted instrument provides additional information for the domains 
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most affected by glucocorticoid use during the participant’s course of treatment. It 
comprises 11 domains (9 of which are shared in common with the C-GTI) and 23 items. 
Note: for the reason mentioned above, the GTI-SL item covering bone mineral density 
decrease (part of the Bone Health domain; Table 15) will not be used in this study. 
The tabular components of the modified GTI are presented in Section 10.12. 
8.4. 
Adverse Events, Serious Adverse Events, and Other Safety 
Reporting 
The definitions of AE and SAE are provided in Appendix 3 (Section 10.3). An AESI is an AE of 
scientific and medical concern specific to the sponsor’s product or program and described in 
Section 8.4.7. 
AEs (including SAEs, AESIs, and AEs of clinical interest) will be reported by the participant (or, 
if appropriate, by the caregiver or surrogate). 
The investigator and qualified designees are responsible for detecting, documenting, and 
recording events that meet the definition of an AE or SAE and monitoring all reported events, 
including those reported by the participant. 
The method of recording, evaluating, and assessing the causality of AEs and SAEs and the 
procedures for completing and transmitting SAE reports are provided in Appendix 3 
(Section 10.3).The method of reporting AESIs is provided in Section 8.4.7. 
8.4.1. 
Time Period and Frequency for Collecting Information on AEs, SAEs, 
and AESIs 
All AEs, SAEs, and AESIs will be collected from the signing of the ICF until the last follow-up 
visit at the time points specified in the SoA (Table 1). 
Medical occurrences that begin before the start of IMP but after obtaining informed consent will 
be recorded as non-treatment-emergent AEs; these will not be included in safety analyses. 
All SAEs and AESIs will be recorded and reported to the sponsor or designee immediately; 
under no circumstance should the reporting time exceed 24 hours (Section 10.3.4). 
The investigator will submit any updated SAE data to the sponsor within 24 hours of it being 
available. 
Investigators are not obligated to actively seek information on AEs or SAEs after conclusion 
of the study participation. However, if the investigator learns of any SAE, including a death, 
at any time after a participant has been discharged from the study, and they consider the event 
to be reasonably related to the IMP or study participation, the investigator must promptly notify 
the sponsor. 
8.4.2. 
Method of Detecting AEs and SAEs 
The method of recording, evaluating, and assessing causality of AE and SAE and the procedures 
for completing and transmitting SAE reports are described in Section 10.3. 
Care will be taken not to introduce bias when detecting AEs and/or SAEs. Open-ended and 
nonleading verbal questioning of the participant is the preferred method to inquire about AE 
occurrences. 
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8.4.3. 
Follow-up of AEs and SAEs 
After the initial AE/SAE report, the investigator is required to proactively follow each participant 
at subsequent visits/contacts. 
All AEs observed from the moment the participant signs the ICF must be followed through 
resolution until one of the following occurs: 
• The participant’s last study visit 
• The participant is lost to follow-up 
• The participant withdraws consent 
Resolution means that the participant has returned to a baseline state of health, or the investigator 
does not expect any further improvement or worsening of the AE. 
Every effort should be made to follow all AEs and SAEs that are considered to be related to IMP 
or study procedures until an outcome can be reported. If the participant is lost to follow-up, 
all AEs will be categorized based on the investigator’s last assessment. 
As long as the participant is still in the study, resolution of SAEs (with dates) should be 
documented on the AE page of the eCRF and in the participant’s medical record to facilitate 
source data verification. If, after follow-up, return to the baseline status or stabilization cannot 
be established, an explanation should be recorded on the SAE form. 
All pregnancies reported during the study should be followed until pregnancy outcome 
(Section 8.4.6). 
For SAEs, AESIs (Section 8.4.7), nonserious AEs, and pregnancies, the sponsor’s designee may 
follow-up by telephone, fax, electronic mail, and/or a monitoring visit to obtain additional case 
details and outcome information (eg, from hospital discharge summaries, consultant reports, 
or autopsy reports) to perform an independent medical assessment of the reported case. 
Further information on follow-up procedures is provided in Section 10.3. 
8.4.4. 
Reporting of AEs and SAEs 
All AEs that occur during the study, from signing of the ICF until the EoTP or the last follow-up 
visit, are to be recorded on the appropriate AE pages (either “serious” or “nonserious”) of the 
eCRF. The investigator should complete all the details requested, including date of onset, time 
of onset, stop date (when applicable), stop time (when applicable), severity, action taken, 
outcome, and relationship to IMP, to corticosteroid (non-IMP) use, and to study procedures. 
Each event should be recorded separately on the eCRF. 
Any SAE, including death due to any cause, which occurs during this study after the signing 
of the ICF, whether or not related to the IMP, must be reported immediately (within 24 hours 
of the study site’s knowledge of the event). Further information on follow-up procedures 
is provided in Section 8.4.3 and Section 10.3. 
The report will contain as much available information concerning the SAE as possible, to enable 
the sponsor (or an authorized representative) to file a report, which satisfies regulatory reporting 
requirements. These timelines apply to initial reports of SAEs and to all follow-up reports. 
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Criteria for documenting the relationship to IMP and severity, outcome, and action taken will be 
the same as those previously described. 
All SAEs that are spontaneously reported within 30 days after the last study visit are to be 
collected and reported in the safety database, and all efforts should be made to follow-up until 
resolution. 
Additional follow-up information should be completed and entered on a paper SAE report form 
and sent by fax/email to the sponsor’s designee. 
8.4.5. 
Regulatory Reporting Requirements for SAEs 
Prompt notification by the investigator to the sponsor of an SAE is essential so that legal 
obligations and ethical responsibilities toward the safety of participants and the safety of IMP 
under clinical investigation are met. 
The sponsor has a legal responsibility to notify both the local regulatory authority and other 
regulatory agencies about the safety of IMP under clinical investigation. The sponsor will 
comply with country-specific regulatory requirements relating to safety reporting to the 
regulatory authority, IRBs/IECs, and investigators. 
An investigator who receives a safety report describing an SAE or other specific safety 
information (eg, summary or listing of SAEs) from the sponsor will review and then file it along 
with the efgartigimod IB and will notify the IRB/IEC, if appropriate according to local 
requirements. 
The sponsor (or designee) is responsible for reporting suspected unexpected serious adverse 
reactions (SUSARs) to the relevant regulatory authorities and IECs/IRBs per applicable 
regulatory requirements. The sponsor (or designee) is also responsible to forward SUSAR 
reports to all investigators involved in the study, who will be required to report these SUSARs to 
their respective IECs/IRBs, per their local regulatory requirements. 
8.4.6. 
Pregnancy 
• If pregnancy is reported, the investigator will record the pregnancy information on the 
appropriate form and submit it to the sponsor within 24 hours of learning of the 
pregnancy in the female participant or the female partner of the male participant. 
Contact details are provided in Serious Adverse Event Reporting. 
• The participant and pregnant female partner, if consented (Section 10.1.3), will be 
followed to determine the outcome of the pregnancy. The investigator will collect 
follow-up information on the participant/pregnant female partner and the neonate and 
forward it to the sponsor. 
• While pregnancy itself is not considered an AE or SAE, any pregnancy complication 
or elective termination of a pregnancy for medical reasons will be reported as an AE 
or SAE. Abnormal pregnancy outcomes (eg, spontaneous abortion, fetal death, 
stillbirth, congenital anomalies, ectopic pregnancy) are considered SAEs and will be 
reported accordingly. 
• Any poststudy pregnancy-related SAE considered reasonably related by the 
investigator to IMP will be reported to the sponsor as described in Section 8.4.4. 
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• Any female participant who becomes pregnant during the study will discontinue IMP. 
8.4.7. 
Adverse Events of Special Interest 
An AESI is an event of scientific and medical concern specific to the sponsor’s product or 
program. Ongoing monitoring and rapid communication by the investigator to the sponsor or 
designee could be appropriate. An AESI can be serious or nonserious, related or not related to 
the IMP or study procedures. 
Efgartigimod treatment leads to reduced IgG levels. Because low IgG levels are associated with 
increased infection risks, events in the MedDRA System Organ Class (SOC) Infections and 
Infestations are considered AESIs in this study. These events will be reported according to the 
time frame specified in Section 8.4.1 and Section 10.3.4, with the following information 
provided: 
• Causal pathogen 
• Location of infection 
• Relationship to an underlying medical condition, medical history, and concomitant 
medications 
• Reoccurrence of a previous infection/infestation 
• Any confirmatory procedure, culture, or urgent medical intervention 
Participants for whom an AESI has been reported may be temporarily interrupted from IMP 
treatment as specified in Section 7.1.2. 
8.4.7.1. 
Risk Mitigation for COVID-19 and Other Significant Infections 
All candidates with clinically significant active infection that is not sufficiently resolved before 
baseline in the investigator’s opinion, recent surgeries, and/or serious diseases will be excluded 
from study participation (exclusion criteria 5C, 6A, 9, and 13A). Additionally, IMP 
administration will be interrupted for any participant who contracts a clinically significant 
infection during the study; IMP administration will resume when the participant is considered 
healthy enough receive IMP. 
A COVID-19 test is performed at screening if required per local regulations (Table 1); 
candidates who test positive will be excluded from taking part in the study. Additionally, 
participants who test positive for COVID-19 or report COVID-19 symptoms at any point during 
the study will have both IMP administration and site visits interrupted until it is considered safe 
to resume both (Section 10.14). If a participant contracts COVID-19, the event is recorded 
and reported as an AESI (Section 8.4.7). 
Refer to Section 10.14 for operational considerations for COVID-19 risk mitigation. 
8.4.8. 
AEs of Clinical Interest 
8.4.8.1. 
Infusion/Injection-Related Reactions 
All therapeutic proteins can elicit immune responses, potentially resulting in hypersensitivity or 
allergic reactions such as rash, urticaria, angioedema, serum sickness, and anaphylactoid or 
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anaphylactic reactions. As with any SC or IV injection, infusion/injection-related reactions can 
occur during or after administrations. Overall, the frequency of injection-related reactions in 
clinical studies has been low. 
Refer to the current efgartigimod IB for more information on infusion/injection-related reactions. 
8.4.8.2. 
Injection Site Reactions 
An injection-site reaction is any AE developing at the injection site. Localized injection site 
reactions are frequently observed in studies in which efgartigimod is comixed with PH20 and 
administered SC. The most frequently reported injection-site reaction AEs are Injection site 
erythema, Injection site pain, and Injection site swelling. 
Any injection-site reaction will be reported as an AE (Section 8.4). Certain types of local 
reactions could be photographed and shared with the sponsor for review and assessment. 
As a routine precaution, participants will be trained or observed closely by a trained health care 
professional for any potential injection-site reaction. 
Refer to the current IB for more information on injection site reactions. 
8.5. 
Pharmacokinetics 
Blood samples for PK analysis will be collected from each participant as described in the SoA 
(Table 1). Samples will be collected predose on IMP administration visits (within ≤2 hours 
before IMP administration) and any time if no IMP is administered. During unscheduled visits, 
blood samples for PK will be collected only if IMP is administered. 
In part A only, 1 additional PK sample will be collected from at least 28 participants on day 10 
(±1 day; should be collected at least 2 days after the second IMP dose is administered at week 1). 
Efgartigimod serum concentrations will be determined using a validated assay. 
The actual date and time of collection of each blood sample will be recorded in the requisition 
form. If no sample is taken, the reason will be recorded in the relevant section of the eCRF. 
8.6. 
Pharmacodynamics 
Blood samples will be collected for the determination of PD markers (total IgG serum levels, 
anti-BP180 and anti-BP230 antibodies, and 
) as described in the SoA (Table 1). 
Total IgG serum levels, anti-BP180 and anti-BP230 antibodies, and 
 will be 
quantified at a central laboratory, and results will only be reported to investigative sites or other 
site staff at screening, to maintain study blind. 
For baseline and all postbaseline PD assessment time points (Table 1), sample collection will 
be performed predose at IMP administration visits (within ≤2 hours before IMP administration). 
PD markers will be determined using validated assays. 
The actual date and time of collection of these blood samples will be recorded in the requisition 
form. If no sample is taken, the reason will be recorded in the relevant section of the eCRF. 
PD blood samples that are collected at the screening visit may be used for methodology 
validation and/or for future research purposes (Section 8.3.6.3). Such use of these samples 
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is only permitted after obtaining consent from the participant; this is described further 
in the ARGX-113-2009 ICF. 
8.7. 
Genetics 
Not applicable to ARGX-113-2009. 
8.8. 
Biomarkers 
Not applicable to ARGX-113-2009. 
8.9. 
Immunogenicity Assessments 
Blood samples will be collected to assess the serum levels of antidrug antibodies (ADA) against 
efgartigimod and plasma levels of antibodies against rHuPH20 as indicated in the SoA (Table 1). 
Samples will be collected predose on IMP administration visits (within ≤2 hours before IMP 
administration). 
All samples will be analyzed in a 3-tiered approach using validated immunogenicity methods. 
First, all samples will be evaluated in a screening assay (tier 1) and scored as positive or 
negative. Second, screened positive samples will be evaluated in a confirmatory assay to assess 
the specificity of the immunogenicity response. The samples will be scored as confirmed positive 
or confirmed negative. Samples confirmed positive in tier 2 will be further analyzed in a titration 
assay to characterize the magnitude of the antibody response and a neutralizing antibody (NAb) 
assay to assess the antibodies for neutralizing activity. 
The actual date and time of collection of these blood samples will be recorded in the requisition 
form. If no sample is taken, the reason will be recorded in the relevant section of the eCRF. 
Immunogenicity blood samples that are collected at the screening visit will only be used 
for methodology validation and/or for future research purposes (Section 8.3.6.3). Such use 
of these samples is only permitted after obtaining consent from the participant; this is described 
further in the ARGX-113-2009 ICF. 
8.10. 
Imaging Substudy 
A photography substudy will be performed at selected study sites. In this substudy, site staff will 
take photographs of bullous lesions located at various anatomical regions of participants per the 
discretion of the investigator. As a guidance, time points of baseline, CDA, CR, and relapse are 
indicated; however, photographs may also be taken at intermediate time points. 
Photography is generally accepted as a routine practice for documenting dermatological 
conditions in medicine. Participants will be requested to provide consent for any use that will 
be made of the image and for sharing anonymized pictures with the sponsor. 
8.11. 
Health Economics OR Medical Resource Utilization and Health 
Economics 
Not applicable to ARGX-113-2009. 
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9. 
STATISTICAL CONSIDERATIONS 
The SAP will be finalized before the interim and final database lock of part A and the final 
database lock of part B, and it will include a more technical and detailed description of the 
statistical analyses described in this section. The below paragraphs contain the main general 
features of the statistical analysis. 
9.1. 
Statistical Hypotheses 
Part A: 
The main goal of part A is to determine whether efgartigimod PH20 SC is effective in the 
treatment of participants with BP via assessment of the study’s primary endpoint: the proportion 
of participants who are in CR while receiving efgartigimod PH20 SC or placebo and have been 
off OCS therapy for ≥8 weeks at week 36. Thus, the null hypothesis to be tested in relation to the 
primary endpoint of part A is as follows: 
• Null hypothesis: efgartigimod PH20 SC is not different from placebo with respect 
to the achievement of CR while receiving efgartigimod PH20 SC or placebo and 
having been off OCS therapy for ≥8 weeks at week 36. 
Part B: 
The primary objective of part B is to demonstrate that efgartigimod PH20 SC is superior to 
placebo in achieving CR while receiving efgartigimod PH20 SC or placebo and having been off 
OCS therapy for ≥8 weeks at week 36. Thus, the null hypothesis to be tested in relation to the 
primary estimand (part B) is as follows: 
• Null hypothesis: efgartigimod PH20 SC is not different from placebo with respect 
to the achievement of CR while receiving efgartigimod PH20 SC or placebo and 
having been off OCS therapy for ≥8 weeks at week 36. 
The null hypotheses corresponding to the estimands for the proposed key secondary endpoints 
of part B (Table 4) are as follows: 
1. Efgartigimod PH20 SC is not different from placebo with respect to the cumulative dose 
of OCS from baseline to week 36. 
2. Efgartigimod PH20 SC is not different from placebo with respect to the proportion 
of participants who achieve an IGA-BP score of 0 while receiving efgartigimod PH20 SC 
or placebo and have been off OCS therapy for ≥8 weeks at week 36. 
3. Efgartigimod PH20 SC is not different from placebo with respect to the proportion 
of participants who achieve CDA while receiving efgartigimod PH20 SC or placebo and 
remained free of relapse through week 36. 
4. Efgartigimod PH20 SC is not different from placebo with respect to the proportion 
of participants in CR while receiving efgartigimod PH20 SC or placebo and receiving 
minimal OCS therapy for ≥8 weeks at week 36. (Minimal OCS therapy is defined as ≤0.1 
mg/kg/day of prednisone or an equivalent dose of another OCS].) 
5. Efgartigimod PH20 SC is not different from placebo with respect to changes from 
baseline in the 24-hour average itch score from the Itch NRS. 
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9.1.1. 
Multiplicity Adjustment 
For part B of the study, the statistical comparisons for the primary endpoint and the key 
secondary endpoints will be carried out in the hierarchical order as indicated above. However, 
after interim analysis of part A data, another multiplicity adjustment testing strategy (eg, Holm’s 
multiplicity adjustment) might be put forward if appropriate. The proposed hierarchical approach 
implies that statistically significant results for the comparison in the higher rank (primary, then 
ranked key secondary variables) are required to initiate the testing of the next comparison in the 
lower rank. Because a fixed-sequence procedure is used, each comparison will be tested at a 
significance level of 0.05 and an overall alpha level of 0.05 will be preserved. 
9.2. 
Analysis Sets 
Table 8 lists and defines the analysis sets to be applied in this study. 
Table 8: 
Analysis Sets for ARGX-113-2009 
Participant Analysis Set 
Description 
Full analysis set 
All randomized participants. Participants will be included in the 
analyses according to the study arms to which they were 
randomized. 
Safety analysis set 
All randomized participants who received at least 1 dose of IMP. 
Participants will be analyzed according to the intervention they 
actually received. 
Per protocol analysis set 
All full analysis set participants who did not have a major 
protocol deviation impacting the efficacy results. The 
determination of the per protocol population will be finalized and 
documented before database lock and unblinding. 
IMP=investigational medicinal product 
The full analysis set is used to analyze endpoints related to the efficacy objectives and the safety 
analysis set is used to analyze the endpoints and assessments related to safety. Sensitivity 
analysis for efficacy will be performed in the per protocol analysis set. 
9.3. 
Statistical Analyses 
9.3.1. 
General Considerations 
In general, data collected will be listed, together with derived variables. Descriptive statistical 
methods will be used to analyze safety and efficacy data. Summaries will generally be provided 
by treatment assignment and overall. 
Summaries for continuous measures will include the number of observations (n), mean, SE, 
median, minimum and maximum. For categorical variables, summaries will include sample size, 
frequencies, and percentages. 
The baseline value will be the last assessment before the first administration of IMP. 
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All study visits will be recalculated based on actual dates and will be referred to as “analysis 
visits” which will be used in the statistical analyses. The rules for calculating the analysis visits 
will be documented in the SAP. Rules for imputing partial dates or missing dates will also 
be documented in the SAP. 
9.3.2. 
Primary Endpoint/Estimand Analysis 
The estimand framework for analysis of the primary endpoint applies only to part B of this study. 
• Population: adult participants with newly diagnosed or relapsing BP, regardless 
of whether the participant is naïve to treatment or has previously received treatment. 
Participants will be receiving concurrent therapy of oral prednisone (or equivalent OCS); 
therefore, candidates who have a known contraindication to OCS will be excluded 
from study participation (exclusion criterion 4). 
• Variable: proportion of participants who are in CR while receiving efgartigimod PH20 
SC or placebo and have been off OCS therapy for ≥8 weeks at week 36. 
• Main intercurrent events (ICE): 
1. Intercurrent treatments before week 36 
a. Immunosuppressants or dapsone at a therapeutic dose for at least 4 weeks 
b. IVIg/SCIg at an immunomodulating dose (at least 1 g/kg/month) 
c. Tetracyclines at therapeutic dose for at least 2 weeks 
d. Rituximab or anti-CD20 biologic, at least 1 infusion 
e. Plasma exchange or immunoadsorption, at least 1 procedure 
f. IV or IM corticosteroids administered in the following conditions: 
- At least 1 administration, any dose, from week 28 to 36 (ie, during the 
8-week period required to confirm CR off OCS therapy) 
- At any time before week 28 in any of the 3 following situations: 
o More than 60 mg/day of prednisone or prednisone equivalent dose for 
3 consecutive days 
o More than 40 mg/day of prednisone or prednisone equivalent dose for 
4 consecutive days 
o More than 7 days in total 
g. Any interventional study drugs under development for BP 
h. Very potent TCS with a weekly dose >20 g for 1 week 
2. Discontinuation of IMP before week 36 due to lack of efficacy 
Population-level summary: the odds ratio (95% confidence interval [CI]) under efgartigimod 
PH20 SC in combination with concurrent OCS therapy versus placebo in combination with 
concurrent OCS therapy. 
Handling of main ICEs: a composite strategy approach will be taken to address both main ICEs. 
This implies that participants who take intercurrent treatments and participants who discontinue 
IMP due to lack of efficacy will be considered nonresponders for the primary endpoint analysis.  
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Handling of missing data: 
• Missing data for reason of 1 of the main ICEs will be handled as described above. 
• If CR information is missing for the primary endpoint, the participant will be 
considered a nonresponder. Further details on other imputation techniques for missing 
CR information will be provided in the SAP. 
• Details on handling other missing data will also be provided in the SAP. 
Final analysis model: the proportion of participants with BP who are in CR while receiving 
efgartigimod PH20 SC or placebo and have been off OCS therapy for ≥8 weeks at week 36 will 
be tested using a Cochran-Mantel-Haenszel (CMH) test stratified for the 2 stratification factors 
of disease history (newly diagnosed versus relapsing) and disease severity (moderate versus 
severe). The odds ratio will be provided, along with the 95% CI and 2-sided p-value. 
Supplementary analyses: to facilitate interpretation of the estimated treatment effect in the 
primary analysis, supplementary analyses will be conducted on the supportive estimand where 
the main ICEs are handled differently (eg, by using the hypothetical or treatment policy strategy 
instead of composite strategy). Details will be provided in the SAP. 
9.3.3. 
Secondary Endpoints Analysis 
9.3.3.1. 
Analysis of Secondary Efficacy Endpoints (Part B Only) 
For part B, there are 5 proposed key secondary endpoints subject to alpha control: 
1. Cumulative dose of OCS from baseline to week 36. 
2. Proportion of participants who achieve an IGA-BP score of 0 while receiving 
efgartigimod PH20 SC or placebo and have been off OCS therapy for ≥8 weeks at week 
36. 
3. Proportion of participants who achieve CDA while receiving efgartigimod PH20 SC or 
placebo and remain free of relapse through week 36. 
4. Proportion of participants who are in CR while receiving efgartigimod PH20 SC or 
placebo and have been receiving minimal OCS therapy for ≥8 weeks at week 36. 
5. Changes from baseline in the 24-hour average itch score from the Itch NRS. 
Details on how to deal with the main ICEs for the proposed key secondary endpoints will be 
provided in the SAP. 
The first proposed key secondary endpoint—cumulative dose of OCS from baseline 
to week 36— will be analyzed in the form of a normalized cumulative OCS dose (NCOD), 
normalizing by weight and by number of days in study and will be denoted as NCOD. 
For the NCOD endpoint, the analysis of covariance (ANCOVA) model will be used to compare 
both study arms. The model will include treatment and the stratification variables will 
be considered as factors. Other secondary efficacy endpoints will be analyzed in a similar 
fashion, as described below: 
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• Cumulative OCS dose at the time the participant exhibits CDA, CR, and CR while 
receiving efgartigimod PH20 SC or placebo and receiving minimal OCS therapy 
for ≥8 weeks 
• CR/PR while receiving efgartigimod PH20 SC or placebo and off OCS therapy for 
≥8 weeks 
• Relapse 
In addition to using the measure NCOD for analyzing the cumulative dose of OCS use over the 
study duration, the term “cumulative OCS use (mg)” will be used and analyzed using descriptive 
statistics. 
The second, third, and fourth proposed key secondary endpoints will be analyzed using a CMH 
test as specified for the primary endpoint. Other secondary efficacy endpoints that are expressed 
as responder proportions will be analyzed similarly. 
The fifth proposed key secondary endpoint—changes from baseline in the 24-hour average itch 
score from the Itch NRS—is measured over time and will be analyzed using a mixed-effect 
model for repeated measures, and the least squares mean difference will be estimated at the 
prespecified time point. 
Additional secondary efficacy endpoints (which are not subject to alpha control) are listed 
in Table 3 and Table 4; these have been selected to further characterize the efficacy of 
efgartigimod PH20 SC in participants with BP. 
9.3.3.2. 
Analysis of Other Secondary Endpoints 
Other secondary endpoints (which are not subject to alpha control) are listed in Table 3 
and Table 4; these have been selected to evaluate other aspects of the effects of efgartigimod 
PH20 SC in participants with BP, including its safety/tolerability, health impact, QoL, PK/PD, 
and immunogenicity. Additionally, this study includes endpoints to evaluate whether participants 
(and/or their caregivers) can competently (self-)administer efgartigimod PH20 SC. 
These endpoints are not subject to multiplicity correction, and their analyses are purely 
descriptive. 
Time to CDA and CR will be tested using a stratified Gehan-Wilcoxon test. The other time 
to event endpoints will be tested using a stratified log-rank test. 
All continuous secondary endpoints (such as the C-GTI and QoL instruments) will be analyzed 
using a mixed-effect model for repeated measures. 
Descriptive statistics will be provided for self-administration training, PD (total IgG serum levels 
and the anti-BP180 and anti-BP230 antibodies), incidence of ADA and NAb against 
efgartigimod, and incidence of antibodies and NAb produced against rHuPH20. Data for 
efgartigimod serum concentrations will be summarized. Total IgG serum levels and autoantibody 
data will be summarized in absolute values, change from baseline, and percent reduction from 
baseline over time. Population PK/PD analysis may be performed based on the PK and PD data 
and reported separately. 
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9.3.3.3. 
Safety Analyses 
Exposure to IMP will be summarized by study arm, separately. 
Summaries of TEAEs, AESIs, SAEs and other safety parameters will be provided by study arm. 
AEs will be classified using the latest version of the Medical Dictionary for Regulatory 
Activities (MedDRA) classification system. AEs, AESIs, and SAEs will be listed corresponding 
to MedDRA SOC and preferred term (PT). Multiple occurrences of a single PT in a patient will 
be counted only once at the maximum severity/grade. Any AEs with missing severity or 
relationship to IMP will be classified as severe and treatment-related, respectively. All AEs will 
be summarized by relatedness to IMP. Any AEs leading to death or discontinuation of IMP will 
also be summarized. 
All TEAEs, AESIs, and SAEs will be analyzed descriptively, all while acknowledging that the 
study population (older adult participants with moderate-to-severe BP) has a high mortality rate, 
a high incidence of existing comorbidities, and an increased risk of developing additional 
comorbid conditions. 
Laboratory parameters, physical examinations, vital sign measurements, and ECG data will also 
be analyzed descriptively. 
9.3.3.4. 
Exploratory Endpoint Analysis 
The exploratory endpoint 
 will be analyzed descriptively in a manner similar 
to that defined for 
 
9.3.3.5. 
Other Analyses 
Subgroup analyses of the primary endpoint and key secondary endpoints will be made to assess 
consistency of the intervention effect across subgroups. 
If the number of participants is too small (less than [10%]) within a subgroup, then the subgroup 
categories may be redefined before unblinding the study. 
Pooled analyses of parts A and B will be performed. 
Details on the above statistical analyses will be provided in the SAP. 
9.4. 
Interim Analysis (Part A) 
An interim analysis will be performed during part A of the study. Results of the interim analysis 
will inform the sponsor’s decision whether to continue part B of the study as currently designed, 
modify the sample size for part B, or discontinue the study (both parts A and B) due to lack of 
efficacy. 
The part A interim analysis will be performed using data collected from all of its participants 
through the data cutoff time point (defined as the last participant in part A who reaches week 26). 
The interim analysis will focus on the primary endpoint (Table 3). However, the analysis of 
secondary endpoints may be considered. Further details on the scope of interim analysis and the 
rules governing adaptations will be included in the SAP. 
Part A endpoints are listed in Table 3. 
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Note: Both part A and part B of the study are randomized and double-blinded; the details 
of the study blinding are described in Section 6.3. The sponsor will take all possible measures 
to ensure that blinding is maintained at the individual participant level while the part A interim 
analysis is being performed. 
9.4.1. 
Futility Analysis 
The target value (TV) of the part A futility analysis will be defined as the value corresponding 
to a treatment difference of 
% between the efgartigimod PH20 SC and placebo arms. 
Similarly, the lower reference value (LRV) will be defined as the value corresponding 
to a treatment difference of 
% between the 2 study arms. 
The sponsor’s decision to proceed with the study (versus a decision to stop the study) 
will be guided by the posterior density of the treatment effect on the study’s primary endpoint 
as a nonbinding futility rule40; this rule will be compared with the aforementioned TV and LRV. 
• The outcome will be considered favorable (“Go”) when the treatment effect is >
% 
with a posterior probability of >80% and when the treatment effect is >
% with a 
posterior probability of >10%. 
• The outcome will be considered inconclusive (“Consider”) when the treatment effect 
is >10% with a posterior probability of <
% and when the treatment effect is >30% 
with a posterior probability of >
%. 
• The outcome will be considered unfavorable (“Stop”) when the treatment effect is 
>
% with a posterior probability of <
%. 
Computer modeling simulations of this analysis—using sample sizes of 20 participants per study 
arm, fixing the response rate in the placebo arm at 
%, and varying the efgartigimod PH20 SC 
response rate between 
and 
%—have displayed suitable operating characteristics: 
the probability of producing a favorable (“Go”) outcome is high when the treatment effect 
is high (Figure 3). 
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• The outcome will be considered favorable (“Go”) if the 
 of the 20 participants 
in the efgartigimod PH20 SC study arm (
%) are responders versus  of the 
20 participants in the placebo arm (
%). 
• The outcome will be considered inconclusive (“Consider”) if the  of the 20 
participants in the efgartigimod PH20 SC study arm (
%) are responders versus  of 
the 20 participants in the placebo arm 
%). 
• The outcome will be considered unfavorable (“Stop”) if the  of the 20 participants 
in the efgartigimod PH20 SC study arm (
%) are responders versus  of the 
20 participants in the placebo arm 
%). 
Note: The potential outcome that is produced from this analysis (favorable, inconclusive, 
unfavorable) will be used for guidance purposes only. The ultimate decision to proceed with 
or stop the study will be based upon a review of all of the available data and proper judgment 
of clinical relevance of the observed outcomes. 
9.5. 
Sample Size Determination 
Part A will randomize 40 participants. No formal sample size calculation is performed for part A. 
The sample size calculation for part B is based on the following assumptions: 
• The primary endpoint is the proportion of participants who are in CR while receiving 
efgartigimod PH20 SC and off OCS therapy for ≥8 weeks at week 36 
• Percentages for sample size calculation: 
− efgartigimod PH20 SC: 
% 
− placebo: 
% 
• 1:1 randomization 
• Power: 90% 
• Significance level: 5% (2-sided) 
A binomial distribution was used to calculate the sample size using PASS 2021 software. 
Table 9 presents the number of participants needed in each arm. 
Table 9: 
Calculation Matrix Applied to Determine the Appropriate Number 
of Participants in Study ARGX-113-2009 
Percentages for Sample 
Size Calculation: 
Efgartigimod 
% 
% 
% 
% 
% 
Placebo 
% 
 
 
 
 
 
% 
 
 
 
 
 
% 
 
 
 
 
 
% 
 
 
 
 
 
% 
 
 
 
 
 
Assuming a clinically relevant difference of 
% and an expectation to achieve the primary 
endpoint in 
% of participants treated with efgartigimod PH20 SC, a total of 120 participants 
(rounding from the sample size of 
 participants, calculated using PASS software) randomized 
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to either the efgartigimod PH20 SC arm or the placebo arm in a 1:1 ratio will yield more than 
90% power in a 2-sided test at the 5% significance level. 
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10. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS 
10.1. 
Appendix 1: Regulatory, Ethical, and Study Oversight 
Considerations 
10.1.1. 
Regulatory and Ethical Considerations 
• This study will be conducted in accordance with the protocol and with the following: 
− Consensus ethical principles derived from international guidelines including the 
Declaration of Helsinki and Council for International Organizations of Medical 
Sciences (CIOMS) international ethical guidelines 
− Applicable International Council for Harmonisation (ICH) Good Clinical Practice 
(GCP) guidelines 
− Applicable laws and regulations 
• The protocol, protocol amendments, ICF, IB, and other relevant documents (eg, 
advertisements) must be submitted to an IRB/IEC by the investigator and reviewed 
and approved by the IRB/IEC before the study is initiated. 
• Any amendments to the protocol will require IRB/IEC approval before 
implementation of changes made to the study design, except for changes necessary to 
eliminate an immediate hazard to study participants. 
• Protocols and any substantial amendments to the protocol will require health 
authority approval before initiation except for changes necessary to eliminate an 
immediate hazard to study participants. 
• The investigator will be responsible for the following: 
− Providing written summaries of the status of the study to the IRB/IEC annually or 
more frequently in accordance with the requirements, policies, and procedures 
established by the IRB/IEC 
− Notifying the IRB/IEC of SAEs or other significant safety findings as required 
by IRB/IEC procedures 
− Providing oversight of the conduct of the study at the site and adherence to 
requirements of 21 CFR, ICH guidelines, the IRB/IEC, European regulation 
536/2014 for clinical studies and all other applicable local regulations 
10.1.2. 
Financial Disclosure 
Investigators and subinvestigators will provide the sponsor with sufficient, accurate financial 
information as requested to allow the sponsor to submit complete and accurate financial 
certification or disclosure statements to the appropriate regulatory authorities. Investigators 
are responsible for providing information on financial interests during the course of the study 
and for 1 year after completion of the study. 
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10.1.3. 
Informed Consent Process 
• Before signing the ICF, participants will be instructed not to participate in any other 
clinical study that involves an intervention or collection of data until the completion 
of the current study. 
• The investigator or his/her representative will explain the following to the participant 
and answer all questions regarding the study: the nature of the study, its purpose, the 
procedures involved, the expected duration, any potential discomfort, potential 
alternative procedure(s) or course(s) of treatment available, and the extent of 
maintaining confidentiality of the participant's records. 
• The investigator or their representative will explain the nature of the study—
including the risks and benefits—to the participant and answer all questions regarding 
the study. 
• Participants must be informed that their participation is voluntary. Participants will be 
required to sign a statement of informed consent that meets the requirements of 21 
CFR 50, local regulations, ICH guidelines, privacy and data protection requirements, 
where applicable, and the IRB/IEC or study center. 
• The medical record must include a statement that written informed consent was 
obtained before the participant was enrolled in the study and the date the written 
consent was obtained. The authorized person obtaining the informed consent must 
also sign the ICF. 
• Participants must be reconsented to the most current version of the ICF(s) during their 
participation in the study if the changes to the ICF affect participant participation. 
• A copy of the ICF(s) must be provided to the participant. 
• Participants who are rescreened are required to sign a new ICF. 
10.1.4. 
Data Protection 
Participants will be assigned a unique identifier by the sponsor. Any participant records or 
data sets that are transferred to the sponsor will contain the identifier only; participant names or 
any information which would make the participant identifiable will not be transferred. 
The participant must be informed that his/her personal study-related data will be used by the 
sponsor in accordance with local data protection law. The level of disclosure must also be 
explained to the participant who will be required to give consent for their data to be used as 
described in the informed consent 
The participant must be informed that his/her medical records may be examined by Clinical 
Quality Assurance auditors or other authorized staff appointed by the sponsor, by appropriate 
IRB/IEC members, and by inspectors from regulatory authorities. 
Photography is generally accepted as routine practice for documenting dermatological conditions 
in medical practice. Photographs may be taken at baseline and at subsequent visits to document 
response and progression. Participants will be requested to provide consent for any use that will 
be made of the image and for sharing anonymized pictures with the sponsor. 
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The ICF will incorporate (or, in some cases, be accompanied by a separate document 
incorporating) wording that complies with relevant data protection and privacy legislation. 
10.1.5. 
Data and Safety Monitoring Board 
The sponsor will appoint an independent DSMB consisting of an independent group of clinical 
experts who are not involved in the study management. They will be supplemented by an 
independent statistician. The objective of the DSMB will be to review all unblinded safety data 
(including the overall number of participants treated up to that point, rates, and participant-level 
details). The planning and frequency of the meetings will be detailed in a DSMB charter. 
In addition, ad hoc meetings can be requested at any time during the study by either the sponsor 
or the DSMB. The DSMB will advise the sponsor regarding continuation, modification, 
or termination of the study after every meeting. 
Additionally, the composition, objectives, role, and responsibilities of the independent DSMB 
will be described in the DSMB charter, and will be agreed upon by the DSMB members and the 
sponsor. The DSMB charter will also define and document the content of the safety summaries 
and general procedures (including communications). 
10.1.6. 
Dissemination of Clinical Study Data 
The sponsor (or its designee) and auditor may access participant records for the purpose 
of monitoring this study, auditing, and managing progress details. The investigator must be fully 
aware that the sponsor (or designee) and auditor can inspect documents to verify the accuracy 
and completeness of a participant’s chart and eCRF records. Such information must be kept 
confidential in locked facilities that allow for this. The investigator will prepare and maintain 
adequate and accurate source documents to record all observations and other pertinent data 
for each participant enrolled into the study. 
The investigator is responsible for maintaining source documents. These will be made available 
for verification by the sponsor’s designee monitor at each monitoring visit. The investigator must 
submit an eCRF for each participant, regardless of duration of participation or administration of 
IMP (ie, an eCRF has to be submitted for screen failures as well). All supportive documentation 
submitted with the eCRF, such as laboratory or hospital records, should be clearly identified with 
the study and participant number. Any personal information, including participant name, should 
be removed or rendered illegible to preserve data privacy. 
10.1.7. 
Data Quality Assurance 
All participant data relating to the study will be recorded on eCRFs unless transmitted 
to the sponsor (or its designee) electronically (eg, laboratory data). The investigator 
is responsible for verifying that data entries are accurate and correct by electronically signing 
the eCRF. 
Guidance on completion of eCRFs will be provided in the Completion Guidelines Document. 
The investigator must permit study-related monitoring, audits, IRB/IEC review, and regulatory 
agency inspections and provide direct access to source data documents. 
Monitoring details describing strategy, including definition of study critical data items 
and processes (eg, risk-based initiatives in operations and quality such as risk management 
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and mitigation strategies and analytical risk-based monitoring), methods, responsibilities, 
and requirements, including handling of noncompliance issues and monitoring techniques 
(central, remote, or on-site monitoring) are provided in the monitoring plan. 
The sponsor or designee is responsible for the data management of this study, including quality 
checking of the data. 
The sponsor assumes accountability for actions delegated to other individuals (eg, contract 
research organizations). 
Study monitors will perform ongoing source data verification to confirm that data entered into 
the eCRF by authorized site staff are accurate, complete, and verifiable from source documents; 
that the safety and rights of participants are being protected; and that the study is being 
conducted in accordance with the currently approved protocol and any other study agreements, 
ICH GCP, and all applicable regulatory requirements. 
10.1.7.1. Data Handling and Record Keeping 
It is the investigator’s responsibility to maintain essential study documents (records and 
documents pertaining to the conduct of this study and the distribution of IMP, including 
regulatory documents, eCRFs, signed participant ICFs, laboratory test results, IMP inventory 
records, source documents, relevant correspondence, AE reports, and all other supporting 
documentation) as required by the applicable national regulatory requirements. The study site 
should plan on retaining such documents for approximately 25 years after study completion. The 
study site should retain such documents 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 after the formal discontinuation of clinical 
development of the IMP. The sponsor will notify the principal investigator of these events. 
These documents should be retained for a longer period if required by the applicable regulatory 
requirements or the hospital, institution, or private practice in which the study is being 
conducted. Participant identification codes (ie, participant names and corresponding study 
numbers) will be retained for this same period of time. These documents may be transferred to 
another responsible party, acceptable to the sponsor, who agrees to abide by the retention 
policies. The investigator is required to notify the sponsor (or an authorized representative) in 
writing before changing the location or status of any essential clinical study documents. The 
investigator must contact the sponsor before disposing of any study records. 
No records should be disposed without the written approval of the sponsor, argenx. 
For studies conducted outside the US under an US investigational new drug (IND), the principal 
investigator must comply with US Food and Drug Administration IND regulations and with 
those of the relevant national and local health authorities. 
10.1.7.2. Quality Assurance Audit 
Study processes, study sites (including, but not limited to site visits, central laboratories, 
vendors), the study database, and study documentation may be subject to quality assurance audit 
during the course of the study by the sponsor or sponsor’s designee on behalf of sponsor. In 
addition, inspections may be conducted by regulatory bodies at their discretion. 
Such audits/inspections can occur at any time during or after completion of the study. 
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10.1.7.3. Quality Control 
Quality control will be applied to each stage of study-related activities. 
The following steps will be taken to ensure the accuracy, consistency, completeness, 
and reliability of the data: 
• Investigator meetings 
• Central laboratories for clinical laboratory parameters 
• Site initiation visit 
• Routine site monitoring 
• Ongoing site communication and training 
• Ongoing oversight by sponsor’s designee of safety parameters and adherence to 
selection criteria 
• Eligibility review by sponsor’s designee and medical monitors 
• Data management quality control checks 
• Continuous data acquisition and cleaning 
• Quality control check of the clinical study report (CSR) 
• To avoid interobserver variability, every effort should be made to ensure that the 
same individual who made the initial baseline determinations completes all efficacy 
and safety evaluations. 
In addition, periodic audits can be performed as specified in Section 10.1.7.2. 
When audits or inspections are conducted, access must be authorized for all study-related 
documents including medical history and concomitant medication documentation 
to the authorized sponsor’s representatives and regulatory authorities. 
10.1.8. 
Source Documents 
Source documents provide evidence for the existence of the participant and substantiate 
the integrity of the data collected. Source documents are filed at the investigator’s site. 
Data entered on the eCRF that are transcribed from source documents must be consistent 
with the source documents or the discrepancies must be explained. The investigator may need 
to request previous medical records or transfer records, depending on the study. Also, current 
medical records must be available. 
The investigator must maintain accurate documentation (source data) that supports 
the information entered on the eCRF. 
Study monitors will perform ongoing source data verification to confirm that data entered into 
the eCRF by authorized site staff are accurate, complete, and verifiable from source documents; 
that the safety and rights of participants are being protected; and that the study is being 
conducted in accordance with the currently approved protocol and any other study agreements, 
ICH GCP, and all applicable regulatory requirements. 
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10.1.9. 
Monitoring 
The sponsor has engaged the services of a designee to perform all clinical study monitoring 
functions within this clinical study. The sponsor’s designee monitors will work in accordance 
with its SOPs. 
Monitoring visits must be conducted according to the applicable ICH GCP guidelines to verify 
that, among others, the: 
• Data are authentic, accurate, and complete 
• Safety and rights of participants are being protected 
• The study is conducted in accordance with the currently approved protocol, any other 
study agreements, and all applicable regulatory requirements. 
The investigator and the head of the medical institution (where applicable) agree to allow 
the sponsor’s designee monitor direct access to all relevant documents. 
The investigator must ensure provision of reasonable time, space, and qualified staff 
for monitoring visits. 
The sponsor’s designee will perform an eCRF review, source document verification (wherever 
allowed per local regulations), and source document review. 
The source documentation agreement form describes the source data for the different data 
on the eCRF. This document should be completed and signed by the sponsor’s designee 
and the investigator, and should be filed in the investigator’s study file. Any data item for which 
the eCRF will serve as the source must be identified, agreed, and documented in the source 
documentation agreement form. 
Upon completion or premature discontinuation from the study, the sponsor’s designee will 
conduct site closure activities with the investigator and site staff as appropriate, in accordance 
with applicable regulations, ICH GCP guidelines, and sponsor/designee procedures. 
10.1.10. 
Data Management 
Data generated within this clinical study will be processed according to the SOPs of the data 
management and biostatistics departments of the sponsor’s designee. 
Case report forms are provided for each participant in electronic format (ie, eCRF). Data will 
be transcribed by the study site staff from the source documents onto the eCRF, per local 
regulations. Data must be entered in English. Guidelines for eCRF completion, including the 
collection of the investigator’s e-signature, will be provided by the sponsor’s designee. 
Appropriate training and security measures will be completed by the investigator and all 
designated site staff before the study being initiated, and any data being entered into the system 
for any study participant at the site. 
The eCRF is essentially considered a data entry form and should not constitute the original 
(or source) medical records unless otherwise specified. Only if requested per local regulations, 
no data collection or source data verification will be performed on race and ethnicity. Source 
documents are all documents used by the investigator or hospital that relate to the participant’s 
medical history, that verify the existence of the participant, the inclusion and exclusion criteria, 
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and all records covering the participant’s participation in the study. They can include laboratory 
notes, ECG results, memoranda, pharmacy dispensing records, participant files, etc. The eCRFs 
should be completed by the investigator or a qualified designee from the site as soon as the data 
are available. 
As a matter of regulation, the investigator is responsible for the accuracy and authenticity of all 
clinical data entered onto eCRFs. Before database lock, each completed eCRF must be reviewed 
for accuracy by the investigator, corrected as necessary, and then approved. The investigator’s 
e-signature serves to attest that the information contained on the eCRFs has been reviewed 
by the investigator and is true and accurate. The investigator will be required to electronically 
sign off the eCRF. 
The data will be verified for completeness, missing data, inconsistencies, and for necessary 
medical clarifications. Queries arising from these checks will be flagged to the study site, 
and the study site staff will correct data, confirm, or clarify data as appropriate. The sponsor’s 
designee will provide the details of the review process in a data management plan and a 
monitoring plan. Any change, including the issuing of queries, will be fully audit-trailed 
by the electronic data capture (EDC) system, meaning the name of the person, time, and date 
stamp, and the reason for change are captured. 
Data will also be provided by third party vendors, such as the results generated by the central 
laboratories, ECG reader, etc. These data will need to be reconciled with the data recorded 
on the eCRF before it can be merged with the eCRF data into the clinical database. 
The sponsor’s designee will provide a data management plan detailing this reconciliation. 
AEs, concomitant diseases, and medical history terms will be assigned to a lowest level term 
and a PT, and will be classified by high level term, high level group term, and primary SOC 
according to the MedDRA thesaurus. 
Prior and concomitant medications, including concomitant BP therapy, will be classified 
according to active drug substance using the World Health Organization (WHO) drug dictionary 
(WHODD). The generic name, the preferred name, and the WHO name will be assigned using 
the WHODD thesaurus. 
The anatomical therapeutic chemical classes will be assigned to prior and concomitant 
medications. Prior and concomitant procedures will be coded according to the MedDRA 
thesaurus. 
10.1.11. 
Study and Site Start and Closure 
10.1.11.1. General Considerations 
The study start date is the date on which the clinical study will be open for recruitment 
of participants, upon availability of mandatory approvals. 
The sponsor or designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the sponsor. Study sites will be closed upon study 
completion. A study site is considered closed when all required documents and study supplies 
have been collected and a study site closure visit has been performed. 
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10.1.11.2. Site Closure 
The investigator may initiate study site closure at any time, provided there is reasonable cause 
and sufficient notice is given in advance of the intended termination. 
Reasons for the early closure of a study site by the sponsor may include but are not limited to: 
• Safety concerns as recommended by the DSMB 
• Inability to achieve the recruitment target within a reasonable time 
• Determination that no further benefits are expected from the study (in the sponsor’s 
judgment) 
• Failure of the investigator to comply with the protocol, the requirements of the 
IRB/IEC or local health authorities, the sponsor’s procedures, or GCP guidelines 
• Discontinuation of further study medication development 
Study sites can also be closed for any reason by the IRB/IEC. The sponsor may close individual 
study sites prematurely for reasons such as poor protocol compliance or unsatisfactory 
recruitment of participants. 
10.1.11.3. Study Closure 
The sponsor can halt the study and conduct a review of safety data if any of the following occur 
during either part A or B: 
• 2 or more participants have safety findings that are considered unacceptable for the 
study population 
• 2 or more study participants have the same (or similar) severe AE that is considered 
to be related or possibly related to the IMP 
In both of the cases noted above, the study may resume (with resumption of IMP administration) 
following the conclusion of a safety data review and a favorable recommendation by the DSMB. 
Additionally, the sponsor can halt the study for any other reason. 
If the study is prematurely terminated or suspended, the sponsor shall promptly inform 
the investigators, the IECs/IRBs, the regulatory authorities, its designee, and any vendors used 
in the study of the reason for termination or suspension, as specified by the applicable regulatory 
requirements. The investigator shall promptly inform the participant and should assure 
appropriate participant therapy and/or follow-up. 
The study can also be terminated by the regulatory authority for any reason. 
10.1.12. 
Investigator Obligations 
This study will be conducted by qualified investigators under the sponsorship of argenx 
(the sponsor). 
The name and telephone/fax numbers of the sponsor’s and designee’s contact staff are listed in 
the investigator study file provided to each site. 
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The investigator is responsible for ensuring that all study site staff, including subinvestigators, 
adhere to all applicable regulations and guidelines, including local laws and regulations, 
regarding the study, both during and after study completion. The investigator is responsible for 
informing the IRB/IEC of the progress of the study and for obtaining annual IRB/IEC renewal. 
The investigator is responsible for informing the IRB/IEC of completion of the study and will 
provide the IRB/IEC with a summary of the results of the study. 
The investigator will comply with the protocol that has been approved/given favorable opinion 
by the IRB/IEC, according to ICH GCP and applicable regulatory requirements. The investigator 
is ultimately responsible for the conduct of all aspects of the study at the study site and verifies 
by signature the integrity of all data transmitted to the sponsor. The term “investigator” as used 
in this protocol and other study documents, refers to the investigator or site staff that 
the investigator has designated to perform certain duties. Subinvestigators or other designated 
site staff are eligible to sign for the investigator, except where the investigator’s signature 
is specifically required. 
10.1.13. 
Protocol Signatures 
After reading the protocol, each site’s principal investigator will sign the protocol signature page 
and send a copy of the signed page to the sponsor (or its designee). By signing the protocol, 
the principal investigator confirms in writing that they have read, understands, and will strictly 
adhere to the study protocol, and will conduct the study in accordance with ICH tripartite 
guidelines for GCP and applicable regulatory requirements. The study will not be able to start 
at any site where its principal investigator has not signed the protocol. 
10.1.14. 
Publication Policy 
All information regarding efgartigimod PH20 SC supplied by the sponsor to the investigator and 
all data generated as a result of this study, are considered confidential and remain the sole 
property of the sponsor. The results of the study will be reported in a CSR. 
The CSR written in accordance with the ICH E3 guideline, will be submitted in accordance 
with local regulations. 
The results of this study may be published or presented at scientific meetings. Any manuscript, 
abstract or other publication, presentation of results, or information arising in connection with 
the study must be prepared in conjunction with the sponsor after the study has been analyzed 
and reported and must be submitted to the sponsor for review and comment before submission 
for publication or presentation. This allows the sponsor to protect proprietary information 
and to provide comments. Study participant identifiers will not be used in the publication 
of results. 
The sponsor will comply with the requirements for publication of study results. In accordance 
with standard editorial and ethical practice, the sponsor will generally support publication 
of multicenter studies only in their entirety and not as individual site data. In this case, 
a coordinating investigator will be designated by mutual agreement. 
Authorship will be determined by mutual agreement and in line with International Committee 
of Medical Journal Editors criteria authorship requirements, based on scientific input and 
recruitment efforts. 
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The sponsor will register and/or disclose the existence of and the results of clinical studies 
as required by law. 
 
 
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10.2. 
Appendix 2: Clinical Laboratory Tests 
• The tests listed in Table 10 will be performed as described in the laboratory manual. 
• Protocol-specific requirements for inclusion or exclusion of participants are detailed 
in Section 5.1 and Section 5.2. 
• Additional tests may be performed at any time during the study as determined 
necessary by the investigator or required by local regulations. 
• Investigators must document their review of each laboratory test report. 
• Retesting during screening to assess eligibility may be performed at a local 
laboratory. 
Table 10: 
Protocol-Required Laboratory Tests 
Laboratory Test 
Parameters 
Hematology 
RBC count 
platelet count 
hemoglobin 
hematocrit 
RBC indices: 
MCV 
MCH 
% reticulocytes 
WBC count with differential: 
neutrophils 
eosinophils 
lymphocytes 
basophils 
monocytes 
Clinical chemistrya 
ALT 
AST 
ALP 
albuminb 
bilirubin (total and direct) 
BUN 
calcium 
creatinine 
CRP 
GGT 
glucose 
glycosylated  
hemoglobin (HbA1c) 
potassium 
sodium 
total proteinb 
Lipid panel: 
total cholesterol 
HDL 
LDL (measured, not calculated) 
triglycerides 
Routine urinalysis 
Specific gravity 
pH, glucose, protein, blood, ketones, bilirubin, urobilinogen, nitrite, leukocyte esterase 
Microscopic examination (if blood or protein is abnormal) 
Pregnancy testing 
Highly sensitive serum hCG pregnancy serum test at screening and urine test at other time 
points (as needed for women of childbearing potential, defined in Section 10.4.1)c  
Specialty 
laboratory tests 
aPTT 
INR 
 
Other screening 
tests 
COVID-19 test (performed if required per local regulations) 
Tuberculosis QuantiFERON (or another regionally-approved IGRA test that has similar 
validity [eg, T-SPOT]d) 
Serology for HBV, HCV, HIV (exclusion criterion 13A and Section 8.3.7) 
ALP=alkaline phosphatase; ALT/SGPT=alanine aminotransferase/serum glutamic pyruvic transaminase; 
aPTT=activated partial thromboplastin time; AST/SGOT=aspartate aminotransferase/serum glutamic oxaloacetic 
transaminase; BUN=blood urea nitrogen; CRP=C-reactive protein; CT=computerized tomography; GGT=gamma-
glutamyl transferase; hCG=human chorionic gonadotropin; HBV=hepatitis type B; HCV=hepatitis type C; 
HDL=high-density lipoprotein; IEC=Independent Ethics Committee; IGRA=interferon gamma release assay; 
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INR=international normalized ratio; IRB=Institutional Review Board; LDL=low-density lipoprotein; MCH=mean 
corpuscular hemoglobin; MCV=mean corpuscular volume; RBC=red blood cell; WBC=white blood cell 
a Blood for clinical chemistry testing will be sampled from nonfasted participants. 
b Albumin and total protein will not be reported to the site and a system will be implemented that will alert the 
investigator of out-of-range values, to allow for appropriate safety follow-up. 
c Local urine testing will be standard for the protocol unless serum testing is required by local regulation or 
IRB/IEC. 
d Additional testing (such as chest CT scan or X-ray) may be performed at the investigator's discretion to confirm 
whether the participant has an active tuberculosis infection. 
10.2.1. 
Other Screening Tests 
10.2.1.1. COVID-19 
COVID-19 testing will be performed at screening if required according to local regulations; 
individuals with positive test results are excluded from taking part in the study (exclusion 
criterion 6A). 
Additional COVID-19 testing recommendations/guidelines are presented in Section 10.14. 
10.2.1.2. QuantiFERON-TB, IGRA Test and Testing for Active Tuberculosis Infection 
A QuantiFERON-TB (or another regionally-approved IGRA test that has similar validity [such 
as the T-SPOT]) can be measured in the central laboratory for each participant at screening to 
determine whether they have antibodies against Mycobacterium tuberculosis. The assessment 
can be based on central or local laboratory samples taken at screening. Additional testing (such 
as a chest computerized tomography [CT] scan or X-ray) may be performed at the investigator's 
discretion to determine whether the participant has an active TB infection. 
10.2.1.3. Hepatitis B Virus 
Participants with an active acute or chronic hepatitis B viral infection at screening cannot 
be enrolled in the study. 
The following combinations of serologic markers will be used to identify an active HBV 
infection (https://www.cdc.gov/hepatitis/HBV/PDFs/SerologicChartv8.pdf): 
Table 11: 
Interpretation of Hepatitis B Serological Test Results 
Test Result 
Interpretation 
HBsAg 
Anti-HBc 
Anti-HBs 
Positive 
Positive 
Negative 
The patient cannot be enrolled in the study because the test 
results indicate an active HBV infection.  
Negative 
Positive 
Negative 
The patient cannot be enrolled in the study because the test 
results indicate a low-level chronic HBV infection with 
impaired liver function.a 
anti-HBc=total hepatitis B core antibody; anti-HBs=hepatitis B surface antibody; HBsAg=hepatitis B surface 
antigen; HBV=hepatitis B virus 
aThis decision will be made by a medical doctor with sufficient experience in hepatology or infectious disease. 
Additional tests (eg, HBV viral load) may be required to determine the status of the participant. 
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10.2.1.4. Hepatitis C Virus 
Participants with an active acute or chronic hepatitis C viral infection at screening cannot be 
enrolled in the study. The hepatitis c virus antibody serologic test will be used to identify an 
active hepatitis C viral infection as indicated in Table 12. 
Table 12: 
Interpretation of the Hepatitis C Antibody Test 
HCV Ab  
Test Result 
Interpretation 
Positive 
The patient cannot be enrolled in the study because the test results indicate an active 
acute or chronic HCV infection unless associated with a negative HCV RNA test. 
HCV=hepatitis C virus; HCV Ab=hepatitis C virus antibody; RNA=ribonucleic acid 
10.2.1.5. Human Immunodeficiency Virus 
Participants who are HIV positive and do not have an AIDS-defining condition or a CD4 count 
200 cells/mm3 at screening can be enrolled in the study if they are adequately treated with 
antiviral therapy (Table 13). Participants who are HIV positive and have an AIDS-defining 
condition or a CD4 count <200 cells/mm3 at screening cannot be enrolled in the study. The 
following are considered AIDS-defining conditions: 
• Cytomegalovirus retinitis with loss 
of vision 
• Mycobacterium tuberculosis (pulmonary 
or extrapulmonary) 
• Pneumocystis jiroveci pneumonia 
• HIV-related encephalopathy 
• Chronic intestinal cryptosporidiosis 
• Invasive cervical cancer 
Table 13: 
Interpretation of HIV Test Results 
HIV test result 
Clinical condition/ 
CD4 Count/viral load 
Interpretation 
Positive 
AIDS-defining condition is 
present or CD4 
count <200 cells/mm3 
Test results and clinical conditions or 
CD4 count confirm AIDS diagnosis, which 
is exclusionary 
Viral load >200 copies/mm3 
despite participant receiving 
antiretroviral therapy 
Participant ineligible because the 
antiretroviral therapy is not adequate 
Viral load <200 copies/mm3 but 
participant not receiving 
antiretroviral therapy 
Participant ineligible because not receiving 
antiretroviral therapy 
AIDS=acquired immune deficiency syndrome; HIV=human immunodeficiency virus 
 
 
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10.4. 
Appendix 4: Contraceptive and Barrier Guidance 
10.4.1. 
Women of Childbearing Potential Definition 
A woman is considered to be of childbearing potential (WOCBP) unless she is either: 
a. Postmenopausal: A postmenopausal state is defined by continuous amenorrhea for at 
least 1 year without an alternative medical cause with an FSH measurement of >40 IU/L. 
If a postmenopausal woman is using hormonal therapy, such as hormone replacement 
therapy or hormonal contraceptives, FSH levels might be suppressed; therefore, an FSH 
test to confirm a postmenopausal state is not considered valid. In a case such as this, the 
postmenopausal state will need to be assessed by the investigator. 
b. Surgically sterilized: Women who have had a documented permanent sterilization 
procedure (eg, hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) 
10.4.2. 
Contraception Guidance 
10.4.2.1. Female Contraception for Women of Childbearing Potential 
WOCBP must use 1 of the following contraception methods from the time of signing the ICF 
until the date of their last dose of IMP. 
1. Combined (estrogen- and progestogen-containing) hormonal contraception associated 
with inhibition of ovulation: 
a. Oral 
b. Intravaginal 
c. Transdermal 
2. Progestogen-only hormonal contraception associated with inhibition of ovulation: 
a. Oral 
b. Injectable 
c. Implantable 
3. Intrauterine device (IUD) 
4. Intrauterine hormone-releasing system (IUS) 
5. Bilateral tubal occlusion 
6. Vasectomized partner 
7. Sexual abstinence: a highly effective method only if defined as refraining from 
heterosexual intercourse during the entire period of risk associated with the IMP. 
The reliability of sexual abstinence needs to be evaluated in relation to the duration 
of the study and the preferred and usual lifestyle of the participant 
8. Progestogen-only oral hormonal contraception in which inhibition of ovulation is not the 
primary mode of action 
a. Oral 
b. Injectable 
c. Implantable 
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9. Male or female condom with or without spermicide 
10. Cap, diaphragm, or sponge with spermicide 
10.4.2.2. Male Contraception 
No male contraception is required. 
 
 
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10.6. 
Appendix 6: Investigator Global Assessment of Bullous Pemphigoid 
(IGA-BP) 
It is not necessary that all characteristics under morphological descriptors be present to meet 
criteria for an IGA score. 
Score 
*Morphological Descriptors 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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10.13. 
Appendix 13: Country-Specific Requirements 
The following lists modifications to the protocol’s existing text that are required for specific 
countries. Cross-references to applicable sections of the protocol are included with each item. 
10.13.1. 
Japan 
A Japanese patient is defined as a patient who was born in Japan and currently lives in Japan 
with Japanese nationality, has not lived outside of Japan for a total of >10 years, and whose 
parents and 4 grandparents are Japanese. 
10.13.2. 
China 
PD and immunogenicity blood samples that are collected from participants in China at screening 
may be used to develop and validate methods to support the efgartigimod development program. 
Such use of these samples is only permitted after obtaining approval from the Human Genetic 
Resources Administration of China (HGRAC), and the methods in which they are used must 
comply with local regulations. Additionally, the conditions in which these samples are stored and 
ultimately destroyed must comply with HGRAC requirements and other relevant regulations 
(Section 8.6 and Section 8.9). 
In China, oral methylprednisolone will be provided instead of oral prednisone (Section 6.8.1.3). 
For concurrent oral methylprednisolone dose adjustment regimen, refer to Table 16. 
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Notes: Each new dosage must be maintained for at least 2 weeks provided that no new lesions (transient or nontransient) appear. Duration of tapering steps from 
escalated doses (>0.5 mg/kg/day) may be shortened based on clinical judgment. 
a Body weight should be rounded to the nearest whole number. 
b The investigator should not deviate from the recommended concurrent oral methylprednisolone dosing regimen, except in matters where the safety of the 
participant may be compromised. 
 
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10.14. 
Appendix 14: Operational Considerations for COVID-19 Risk 
Mitigation 
During the study, the sites will implement all recommendations issued by the local government 
regarding the spread of COVID-19, including specific guidelines related to clinical research 
performed in clinical research centers. 
This appendix is intended for use only if unforeseen changes in the COVID-19 pandemic lead to 
new restrictions at the site, or if new risks for participants or site staff prevent them from 
attending visits at the site. The sponsor/designee and the study site must agree to the duration of 
these changes. 
10.14.1. 
Testing for COVID-19 
Additional testing for COVID-19 beyond what is listed in the SoA (Table 1) is not required 
during the study. However, it is recommended that participants who develop COVID-19 
symptoms be tested, and the results be reported for the study. 
During the pandemic, the site staff should contact participants before each visit to inquire about 
COVID-19 symptoms (eg, fever, cough, sneezing, loss of taste/smell, difficulties breathing/chest 
tightness) and exposure to determine if it is safe for the participant to proceed with the visit as 
planned. If a participant tests positive for SARS-CoV-2 or has symptoms of COVID-19, they 
should not return to the site for visits (nor should home nurses visit the participant’s home for 
home visits) until the investigator determines it is safe to return to normal study visit procedures, 
based on local regulations and guidance from the site staff. 
Critical Parameters to Be Collected During the Study 
All assessments should be performed as indicated in the SoA (Table 1). If assessments cannot be 
performed due to the COVID-19 pandemic, the following critical parameters must be collected: 
all AE reporting, injection site reactions, IMP administration, questionnaires, and safety 
laboratory assessments from the first visit through the end of study. 
10.14.2. 
Study Protocol Changes 
If the COVID-19 pandemic results in significant participant discontinuation, the sites may 
increase the recruitment of potential participants to replace the lost participants. 
Critical Parameters to Be Collected During the Study 
All assessments should be performed as indicated in the SoA (Table 1) if possible. In the event 
that some assessments cannot be performed due to the COVID-19 pandemic, the following 
critical parameters must be collected: all AE reporting, injection site reactions, IMP 
administration, OCS dose adjustment, disease assessment, and safety laboratory assessments 
from the first visit through the end of treatment. 
10.14.3. 
Mandatory Site Visits 
All visits that are designated as mandatory on-site visits (baseline [week 0] and weeks 1-4, 8, 12, 
16, 20, 24, 26, 28, 32, 36, 39, and 43) must be performed at the site. If adaptations are required 
due to the COVID-19 pandemic, the following visits should be performed at the site if possible: 
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• Screening visit 
• Baseline/day 1 [Note: Participants cannot be randomized to either of the study arms 
unless this visit occurs on-site] 
• EoTP/ETD/ESD visits 
During the COVID-19 pandemic, other study visits designated as mandatory on-site visits 
(weeks 1-4, every fourth weekly visit thereafter through week 36, and weeks 26, 39, and 43; 
[Table 1]) may be performed at the participant’s home (or an alternate convenient location). 
Such home visits will include sample collections as described in Table 17. 
A home nurse will travel to the participant’s home to conduct these visit (or the participant will 
go to the alternate convenient location). The investigator will talk to the participant via an audio 
or video interview to elicit AEs and concomitant medications, as well as the general well-being 
of the participant. The investigator will also perform efficacy assessments using an audio or 
video interview with the participant. These assessments (via audio/video interview) will be 
conducted before the home nurse administers IMP. 
The division of tasks between the investigator and home nurse are indicated in Table 17. 
In the exceptional case that a home nurse cannot be identified or cannot travel to the participant’s 
home, vital sign measurements and blood and urine collection will not be performed. IMP may 
be administered through self- or caregiver-supported administration, provided that the participant 
or caregiver has completed the training and have been determined competent. Such an exception 
will require concurrent sponsor and investigator approval on a case-by-case basis. 
Table 17: 
Scheme for Study Visits Performed at Home During a COVID-19 Pandemic 
Critical Assessment 
Performed By: 
Method of Assessment 
Updates/addenda to original informed consent 
(other than those conducted at screening and 
baseline visits) 
Investigator 
Audio or video interview 
Disease assessment (CDA, PR, CR, relapse, 
treatment failure)a 
Investigator 
Audio or video interview 
Adverse events 
Investigator 
Audio or video interview 
Concomitant medications 
Investigator 
Audio or video interview 
OCS dose adjustment evaluation 
Investigator 
Audio or video interview 
Vital sign measurements 
Home nurseb 
In person at participant’s homec 
Blood collection (for safety assessments only) 
Home nurseb 
In person at participant’s homec 
Urine collection (for safety assessments only) 
Home nurseb 
In person at participant’s homec 
IMP administration 
Home nurseb 
In person at participant’s homec 
BP=bullous pemphigoid; CDA=control of disease activity; CR=complete remission; ICF=informed consent form; 
IMP=investigational medicinal product; OCS=oral corticosteroids (prednisone or equivalent); PR=partial remission. 
a Refer to Section 4.1.3 for BP disease terminology definitions. 
b The home nurse is either a nurse from the study site or a nurse from a commercial nursing vendor who is delegated 
by the investigator. 
c Or at an alternate convenient location for the participant. 
 
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10.15. 
Appendix 15: Protocol Amendment History 
Protocol Version 3.0, Amendment 2 (27 Mar 2023) 
This amendment of the ARGX-113-2009 protocol is considered to be substantial based 
on the criteria set forth in Article 10(a) of Directive 2001/20/EC of the European Parliament 
and the Council of the European Union. 
Overall Rationale for This Amendment 
The primary rationale for this amendment is to incorporate health authority feedback. 
In addition, the changes implemented in the UK-specific protocol v2.1 – UK are included in this 
protocol amendment. Country-specific requirements are indicated in Section 10.13. 
The major changes from protocol version 2.0 to protocol version 3.0 are summarized 
in the following table. Minor editorial changes, including the correction of typographical errors 
and formatting inconsistencies, are not summarized in the table. 
Section number/  
Section title 
Description of change 
Brief rationale for change 
7. IMP Discontinuation and 
Participant Discontinuation/ 
Withdrawal 
This section was revised to 
encourage participants who 
permanently discontinue IMP to 
remain in the study, but only 
attend mandatory on-site visits. 
The circumstances that result in 
IMP discontinuation and study 
withdrawal were revised.  
Health authority requested 
updates. Changes reduce the 
burden on the participants. 
9.5. Sample Size 
Determination 
A clarification of the difference 
between the calculated and actual 
sample sizes was added. 
Health authority requested 
update. 
1.3. Schedule of Activities 
(SoA) 
The visits at weeks 8 and 16 may 
also be performed at home, by 
qualified site staff, for a 
participant who has achieved 
CDA. In these cases, collection of 
the PK, PD, immunogenicity 
blood samples, and weight 
measurements are not required. 
Revisions reduce the burden on 
participants. 
Participants who discontinue IMP 
must now only attend mandatory 
on-site visits. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
1.3. Schedule of Activities 
(SoA) 
8.5. Pharmacokinetics 
On day 10 in part A of the study, 
at least 28 participants, rather than 
all participants, are required to 
have an additional PK sample 
collected. 
Revision reduces the burden on 
participants. Data from at least 
28 participants is sufficient to 
characterize anticipated peak 
concentrations after the second 
administration of efgartigimod 
PH20 SC.  
6.8.3. Rescue Therapy 
IVIg is added as a new option for 
rescue therapy. 
IVIg is a 
nonimmunosuppressive 
treatment option for participants 
who permanently discontinue 
IMP under conditions described 
in the section. 
1.3. Schedule of Activities 
(SoA) 
2.3. Benefit/Risk Assessment 
6.4. Study Intervention 
Compliance 
The length of safety monitoring 
after on-site IMP administration 
was revised to at least 30 minutes. 
Revision aligns with the current 
efgartigimod IB. 
2.3.1, Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009, 
Infusion/injection-related 
reactions  
The frequency of 
infusion/injection-related 
reactions in the studies was added. 
In addition, it was clarified that 
pretreatment, to prevent an 
infusion/injection-related reaction, 
is not required. 
Revision aligns with the current 
efgartigimod IB. 
2.3.1, Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009, Injection 
site reactions 
Injection site reactions were 
added as a potential clinically 
significant risk. 
Injection site reactions are now 
defined as adverse events of 
clinical interest that need to be 
monitored. 
2.3.1, Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009 
Language on the potential risk of 
teratogenicity/fetotoxicity was 
deleted. 
Reproductive toxicity studies 
with efgartigimod did not show 
a teratogenic effect in rat or 
rabbit, nor did it adversely affect 
male and female fertility or the 
reproductive and developmental 
performance in rats. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
However, the measures to 
exclude pregnant or lactating 
females and those who intend to 
become pregnant during the 
study, as well as the immediate 
discontinuation of IMP use in 
case of pregnancy, remain 
unchanged. 
2.3.1, Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009 
Language on potential risk of 
first-time administration of 
efgartigimod PH20 SC to 
participants with BP was deleted. 
This is an inherent risk 
associated with any clinical 
study investigating an IMP for 
the first time in a new patient 
population. Applicable laws, 
regulations, and guidelines 
(Section 10.1.1) are being 
followed to minimize this risk. 
2.3, Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009 
The section title was changed 
from “Immune modulation 
leading to increased infection 
risk” to “Serious infection.” 
The mitigation strategy was 
rephrased. 
Recommendations for additional 
mitigation measures before and 
during the study (Section 8.3.7) 
are listed. 
The potential clinically significant 
risk of “Susceptibility to 
infection” was deleted, as this risk 
is covered under “Serious 
infection.” 
Revisions improve 
comprehension. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
5.2. Exclusion Criteria 
2.3.1., Table 2: Potential Risks 
and Mitigation Strategies for 
ARGX-113-2009 
8.3.7. Infections and 
Vaccinations 
Participants with latent infections 
are excluded from the study. 
Exclusion criterion 5 was revised 
accordingly and renumbered as 
5B. 
Because the mechanism of 
action of efgartigimod involves 
reducing IgG levels, there is a 
potential risk of reactivating the 
infection in participants. 
5.2. Exclusion Criteria 
Exclusion criterion 7, which was 
renumbered as 7A, was revised to 
exclude potential participants with 
any medical condition, that in the 
opinion of the investigator would 
interfere with an accurate 
assessment of clinical symptoms 
of BP, putting the participant at 
undue risk, or prevent participants 
from complying with protocol 
requirements. 
Revision ensures the safety of 
the participant and the integrity 
of the collected data. 
5.2. Exclusion Criteria 
10.2.1.5. Human 
Immunodeficiency Virus 
Table 13: Interpretation of 
HIV Test Results 
Exclusion criterion 13, which was 
renumbered as 13A, now includes 
participants who are HIV positive 
and not adequately treated with 
antiviral therapy. 
Because the mechanism of 
action of efgartigimod involves 
reducing IgG levels, there is a 
potential risk of infection or 
other complications in 
participants.  
5.2. Exclusion Criteria 
8.3.7. Infections and 
Vaccinations 
Participants with total IgG serum 
levels of 4-6 g/L at screening are 
now by default eligible to 
participate in the study. Exclusion 
criterion 14 was revised 
accordingly and renumbered as 
14A. 
Based on emerging data from 
studies with efgartigimod in 
other indications, the sponsor 
has decided that treatment with 
efgartigimod is safe for any 
participant with total IgG serum 
levels ≥4 g/L at screening. 
5.2. Exclusion Criteria 
Exclusion criterion 15, which was 
renumbered as 15A, was revised 
to clarify that the investigator has 
decision-making power. 
Clarification reduces the risk of 
protocol deviations.  
5.2. Exclusion Criteria 
8.3.7. Infections and 
Vaccinations 
Participants who have received a 
live or live-attenuated vaccine 
<4 weeks before the baseline visit 
Because the mechanism of 
action of efgartigimod involves 
reducing IgG levels, and safety 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
are excluded from the study 
(exclusion criterion 17). 
of immunization with live or 
live-attenuated vaccines was not 
studied. 
5.2. Exclusion Criteria 
Participants who are enrolled in 
another interventional clinical 
study are excluded from this study 
(exclusion criterion 18). 
Participants enrolled in other 
clinical studies could confound 
the study results. 
5.2. Exclusion Criteria 
Participants with severe renal 
impairment at screening are 
excluded from this study 
(exclusion criterion 19).  
Due to limited data in patients 
with severe renal impairment, a 
conservative approach was 
taken to exclude patients with 
severe renal impairment from 
clinicals studies with 
efgartigimod. No new signal has 
been identified and the known 
safety profile of efgartigimod 
remain unchanged. 
8.1.2. Screening Period 
This section was revised to 
emphasize that the eligibility of 
potential participants is at the 
discretion of the investigator and 
does not require confirmation 
from the sponsor.  
The investigator determines the 
eligibility of the participants to 
ensure GCP compliance. 
The paragraph was revised to 
clarify that the eligibility 
assessment for total IgG serum 
levels can be based on both 
central and local laboratory 
results obtained at screening. 
In addition, eligibility assessment 
for total IgG serum levels and 
anti-BP 180 and anti-BP230 
antibodies can be based on 
historical laboratory results from 
local samples taken up to 7 days 
before screening. 
Revision allows for faster 
availability of screening results. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
8.2.1.1. Assessment of BP 
Disease Status and OCS Dose 
Monitoring 
1.3. Schedule of Activities 
(SoA) 
A time window for the 
investigator’s weekly call to the 
participant was added: within 
48 hours before the IMP 
administration during the home 
visits. 
Text was added to specify that the 
investigator must check with the 
participant if they have new 
lesions. If the participant reports 
any new lesions, they are 
instructed to visit the clinic for an 
unscheduled appointment. 
Revision ensures that new 
lesions are detected as soon as 
possible.  
8.4.8. AEs of Clinical Interest 
8.4. Adverse Events, Serious 
Adverse Events, and Other 
Safety Reporting 
Events that are not considered to 
be AESIs but still require 
attention or special monitoring 
will be reported. 
Revision aligns with the current 
efgartigimod IB. 
9.3.2. Primary Endpoint/ 
Estimand Analysis 
IV or IM corticosteroids 
administered before week 36 are 
only considered intercurrent 
treatments if administered under 
specific conditions. These 
conditions are specified in the 
protocol.  
Revision supports accurate 
determination of the primary 
endpoint. 
10.2., Table 10: 
Protocol-Required Laboratory 
Tests 
CRP and GGT have been added to 
the list of clinical chemistry 
parameters. 
CRP, an inflammatory marker, 
is used to assess the 
participant’s response to 
treatment and the severity of the 
disease. GGT, a liver enzyme, is 
used to monitor for the potential 
of treatment-associated liver 
damage because of IgG 
deposits. 
10.2., Table 10: 
Protocol-Required Laboratory 
Tests 
Footnote b was added: study sites 
are no longer provided with 
albumin and total protein results 
in real time. The investigator will 
receive an alert if results are 
Revision protects data integrity 
in double-blinded efgartigimod 
studies. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
outside of the normal range, to 
allow for appropriate safety 
follow-up.  
Section 10.4.2.2. Male 
Contraception 
2.3.1. Risk Assessment 
5.1. Inclusion Criteria 
Male contraception is no longer 
required. Inclusion criterion 6 was 
revised accordingly and 
renumbered as 6B. 
Revision aligns with the current 
efgartigimod IB. Reproductive 
toxicology studies did not show 
any effect on male reproductive 
potential.  
10.13.2., Table 16: Concurrent 
Oral Methylprednisolone 
Equivalent Doses (in mg) 
Based on Participant Body 
Weight 
6.8.1.3.Oral Prednisone Dose 
Adjustment Regimen (Based 
on BP Disease Assessment) 
A table with recommendations on 
the concurrent oral 
methylprednisolone dosing 
regimen was added. 
In some countries, 
methylprednisolone is used 
instead of prednisone; therefore, 
recommendations are provided 
for methylprednisolone, in line 
with what was presented for 
prednisone.  
6.8.1.3. Oral Prednisone Dose 
Adjustment Regimen (Based 
on BP Disease Assessment) 
6.8.1.3; Table 7: Concurrent 
Oral Prednisone Equivalent 
Doses (in mg) Based on 
Participant Body Weight 
Text clarifies that for participants 
with body weights of <45 kg or 
≥110 kg, the investigator should 
propose OCS doses and inform 
the medical monitor, to ensure 
consistency within the study. 
The minimum and maximum 
recommended doses for 
participants with body weights 
<45 kg and ≥110 kg, respectively, 
were included in Table 7. 
Revisions provide additional, 
specific information for study 
site staff. 
Text clarifies that participants will 
be considered a treatment failure 
if they do not achieve CDA after 
receiving IMP with the described 
escalated prednisone dosing 
regimen, rather than the 
prednisone dosing regimen only. 
Revision reduces the risk of 
wrongly identifying the 
participant as treatment failure. 
 
 
The tapering step of 0.15 
mg/kg/day was included in the 
Correction as described in the 
Administrative Letter dated 
13 Oct 2022. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
table but was missing from the 
text. 
6.8.2. Prohibited Medications 
and Therapy During the Study 
It is clarified that OCS is allowed, 
however, IV or IM corticosteroids 
are not permitted during the study. 
Revisions provide explicit 
guidance. 
4.1.3. Bullous Pemphigoid 
Disease Status Terminology to 
Be Used in the Study 
The definition of complete 
remission was revised. 
Revision ensures an accurate 
evaluation of CR endpoint. 
4.1.3. Bullous Pemphigoid 
Disease Status Terminology to 
Be Used in the Study 
The definition of relapse was 
aligned with consensus 
terminology. 
Revision aligns with the 
publication of Murrell et al. 
which aims to improve 
consistent reporting of clinical 
outcomes. 
1.3. Schedule of Activities 
(SoA) 
Footnote b was revised to add that 
home administration of IMP is not 
permitted until week 5. 
Revision provides explicit 
guidance. 
1.3. Schedule of Activities 
(SoA) 
8.1.5. Unscheduled Visits 
Footnote f was revised to explain 
in what situations an unscheduled 
visit may be performed (including 
a notable weight change) and that 
the investigator will decide which 
assessments should be conducted 
during the unscheduled visits. 
Revision provides additional, 
specific information for study 
site staff. 
1.3. Schedule of Activities 
(SoA) 
Footnote j was added to allow 
weight measurements when “other 
weekly visits” occur on-site. 
Measuring weight may allow for 
adjustment of concurrent 
prednisone (or equivalent) dose. 
8.1.4. Home Study Visits 
The section was added to clarify 
what happens during other weekly 
visits at home. 
Revision provides additional, 
specific information for study 
staff.  
8.1.3. Treatment and 
Follow-Up Periods 
The sentence stating that all 
participants will complete the 
EoTP visit at week 36 was 
removed. 
Participants who withdrew or 
who permanently discontinued 
the study should not complete 
an EoTP visit. 
10.14.4.,Table 17: Scheme for 
Study Visits Performed at 
The title of Table 17 was revised 
to focus on home visits during a 
COVID-19 pandemic. 
Clarifications reduce the risk of 
protocol deviations. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
Home During the COVID-19 
Pandemic 
The baseline in row 1 was 
incorrectly indicated as being 
week 1. This was corrected to 
week 0. 
The definition of home nurse was 
added. 
2.3.1., Table 2: Potential Risks 
and Mitigation Strategies for  
ARGX-113-2009, 
Infusion/injection-related 
reactions  
Mitigation measures for risks of 
infusion/injection-related 
reactions when IMP is 
administered at home was deleted. 
The risk of 
infusion/injection-related 
reactions is not higher in home 
administrations; no additional 
mitigations are needed. 
2.3.1., Table 2: Potential Risks 
and Mitigation Strategies for  
ARGX-113-2009, Potential 
complications from exposure 
OCS 
The increase of OCS doses based 
on clinical status of participant is 
removed as a mitigation measure 
for complications from exposure 
to OCS. In addition, the table was 
revised to include a more concise 
phrasing of the mitigation strategy 
for potential complications from 
exposure. 
The rapid tapering of OCS is a 
mitigation measure for potential 
complications from OCS 
exposure; however, increasing 
OCS doses is not a mitigation 
measure. 
In addition, revision provides 
additional, specific information 
for study site staff. 
5.1. Inclusion Criteria 
Inclusion criterion 2, which was 
renumbered as 2B, was revised to 
clarify that participants must have 
reached the local legal age of 
consent at the time of signing the 
ICF. 
Criterion was revised to comply 
with local requirements. 
5.4. Screen Failures 
The section was revised to 
distinguish between retesting and 
rescreening participants who fail 
the initial screening.  
Revision provides additional, 
specific information for site 
staff. 
6.1., Table 5: Study 
Interventions 
Table 5 was revised to include the 
IMP name and description, and to 
correct the descriptions of dose 
formulation and unit dose 
strength. 
Correction. 
6.8. Concomitant Therapy 
The text was revised to clarify 
that participants must maintain a 
Clarification reduces the risk of 
protocol deviations. 
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Section number/  
Section title 
Description of change 
Brief rationale for change 
stable regimen of medication 
throughout the study and that 
herbal supplements also include 
Chinese traditional medicine. 
8.6 Pharmacodynamics 
Protocol is revised to clarify that 
total IgG serum levels, anti-BP 
180 and anti-BP 230 antibodies, 
and 
 are 
quantified at a central laboratory, 
and results will only be reported 
to investigative sites or other site 
staff at screening to maintain 
study blind. 
Clarification reduces the risk of 
protocol deviations. 
2. Introduction 
2.3. Benefit/Risk Assessment 
The reference to the rHuPH20 IB 
was removed. 
The rHuPH20 IB is no longer 
part of the submission in 
countries where rHuPH20 is 
considered an excipient and not 
IMP. 
3.1, Table 3: Part A Objectives 
and Endpoints 
3.2, Table 4: Part B Objectives 
and Endpoints 
The endpoints to evaluate the PD 
and immunogenicity of 
efgartigimod PH20 SC 
in participants with BP were 
rephrased.  
Endpoints were not changed. 
Revision ensures correct 
interpretation of endpoints. 
9.3.3.2. Analysis of Other 
Secondary Endpoints 
Text is added to clarify that 
population PK/PD analysis may 
be performed based on PK and 
PD data and reported separately. 
Information added for 
completeness. 
6.3.1. Emergency Unblinding 
Revision emphasizes that the 
sponsor must be notified within 
24 hours if emergency unblinding 
occurred. 
Clarification reduces the risk of 
protocol deviations. 
 
 
 
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11. 
REFERENCES 
1. Schmidt E, Obe K, Brocker E, Zillikens D. Serum levels of autoantibodies to BP180 
correlate with disease activity in patients with bullous pemphigoid. Arch Dermatol. 
2000;136(2):174-178. 
2. Masmoudi W, Vaillant M, Vassileva S, et al. International validation of the Bullous 
Pemphigoid Disease Area Index severity score and calculation of cutoff values for 
defining mild, moderate, and severe types of bullous pemphigoid. Br J Dermatol. 
2021;184(6):1106-1112. 
3. Amagai M, Ikeda S, Hashimoto T, et al. A randomized double-blind trial of intravenous 
immunoglobin for bullous pemphigoid. J Dermatol Sci. 2017;85(2):77-84. 
4. Kasperkiewicz M, Schulze F, Meier M, et al. Treatment of bullous pemphigoid with 
adjuvant immunoadsorption: a case series. J Am Acad Dermatol. 2014;71(5):1018-1020. 
5. Jafari SMS, Gadaldi K, Feldmeyer L, Yawalkar N, Borradori L, Schlapbach C. Effects of 
omalizumab on FcεRI and IgE expression in lesional skin of bullous pemphigoid. Front 
Immunol. 2019;10:1919. 
6. Kridin K, Ludwig RJ. The growing incidence of bullous pemphigoid: overview and 
potential explanations. Front Med. 2018;220. 
7. Wertenteil S, Garg A, Strunk A, Alloo A. Prevalence estimates for pemphigoid in the 
United States: a sex-adjusted and age-adjusted population analysis. J Am Acad Dermatol. 
2019;80(3):655-659. 
8. Tedbirt B, Gillibert A, Andrieu E, et al. Mixed individual-aggregate data on all-cause 
mortality in bullous pemphigoid: a meta-analysis. JAMA Dermatol. 2021;157(4):421-
430. 
9. Joly P, Roujeau J, Benichou J, et al. A comparison of oral and topical corticosteroids in 
patients with bullous pemphigoid. N Engl J Med. 2002;346(5):321-327. 
10. Wojnarowska F, Kirtschig G, Highet AS, Venning VA, Khumalo NP. British Association 
of Dermatologists. Guidelines for the management of bullous pemphigoid. Br J 
Dermatol. 2002;147(2):214-221. 
11. Hull CM, McKenna JK, Zone JJ. Topical corticosteroids and bullous pemphigoid. Arch 
Dermatol. 2003;139(2):225-226. 
12. Guillaume JC, Vaillant L, Bernard P, et al. Controlled trial of azathioprine and plasma 
exchange in addition to prednisolone in the treatment of bullous pemphigoid. Arch 
Dermatol. 1993;129(1):49-53. 
13. Harman KE, Black MM. High-dose intravenous immune globulin for the treatment of 
autoimmune blistering diseases: an evaluation of its use in 14 cases. Br J Dermatol. 
1999;140(5):865-874. 
14. Ahmed AR. Intravenous immunoglobulin therapy for patients with bullous pemphigoid 
unresponsive to conventional immunosuppressive treatment. J Am Acad Dermatol. 
2001;45(6):825-835. 
System Version: 2.0, Status: Approved, Document ID: VV-TMF-87341

Clinical Study Protocol ARGX-113-2009 (BALLAD) v4.0 
27 Feb 2024 
Efgartigimod PH20 SC—BP 
argenx 
Confidential 
151 
15. Kremer N, Snast I, Cohen ES, et al. Rituximab and omalizumab for the treatment of 
bullous pemphigoid: a systematic review of the literature. Am J Clin Dermatol. 
2019;20(2):209-216. 
16. Polansky M, Eisenstadt R, DeGrazia T, Zhao X, Liu Y, Feldman R. Rituximab therapy in 
patients with bullous pemphigoid: a retrospective study of 20 patients. J Am Acad 
Dermatol. 2019;81(1):179-186. 
17. Bouscarat F, Chosidow O, Picard-Dahan C, et al. Treatment of bullous pemphigoid with 
dapsone: retrospective study of thirty-six cases. J Am Acad Dermatol. 1996;34(4):683-
684. 
18. Williams HC, Wojnarowska F, Kirtschig G, et al. Doxycycline versus prednisolone as an 
initial treatment strategy for bullous pemphigoid: a pragmatic, non-inferiority, 
randomised controlled trial. Lancet. 2017;389(10079):1630-1638. 
19. Bernard P, Antonicelli F. Bullous pemphigoid: a review of its diagnosis, associations, and 
treatment. Am J Clin Dermatol. 2017;18(4):513-528. 
20. Witte M, Zillikens D, Schmidt E. Diagnosis of autoimmune blistering diseases. Front 
Med. 2018;5:296. 
21. Di Lernia V, Casanova D, Goldust M, Ricci C. Pemphigus vulgaris and bullous 
pemphigoid: update on diagnosis and treatment. Derm Pract Concept. 
2020;10(3):e2020050. 
22. Murrell D, Daniel B, Joly P, et al. Definitions and outcome measures for bullous 
pemphigoid: recommendations by an international panel of experts. J Amer Acad 
Dermatol. 2012;66(3):479-485. 
23. Bernard P, Bedane C, Prost C, Ingen-Housz-Oro S, Joly P. Bullous pemphigoid: 
guidelines for the diagnosis and treatment. Centres de reference des maladies bulleuses 
auto-immunes. Societe Francaise de Dermatologie. Ann Dermatol Venereol. 
2011;138(3):247-251. 
24. Feliciani C, Joly P, Jonkman M, et al. Management of bullous pemphigoid: the European 
Dermatology Forum consensus in collaboration with the European Academy of 
Dermatology and Venereology. Br J Dermatol. 2015;172(4):867-877. 
25. Schmidt E, Sticherling M, Sardy M, et al. S2k guidelines for the treatment of pemphigus 
vulgaris/foliaceus and bullous pemphigoid: 2019 update. J Dtsch Dermatol Ges. 
2020;18(5):516-526. 
26. Ujiie H, Iwata H, Yamagami J, et al. Japanese guidelines for the management of 
pemphigoid (including epidermolysis bullosa acquisita). J Dermatol. 2019;46(12):1102-
1135. 
27. Joly P, Roujeau J, Benichou J, et al. A comparison of oral and topical corticosteroids in 
patients with bullous pemphigoid. N Engl J Med. 2002;346(5):321-327. 
28. Hull CM, McKenna JK, Zone JJ. Topical corticosteroids and bullous pemphigoid. Arch 
Dermatol. 2003;139(2):225-226. 
System Version: 2.0, Status: Approved, Document ID: VV-TMF-87341

Clinical Study Protocol ARGX-113-2009 (BALLAD) v4.0 
27 Feb 2024 
Efgartigimod PH20 SC—BP 
argenx 
Confidential 
152 
29. Bernard P, Charneux J. Bullous pemphigoid: a review. Ann Dermatol Venereol. 
2011;138(3):173-181. 
30. Bernard P, Reguiai Z, Tancrede-Bohin E, et al. Risk factors for relapse in patients with 
bullous pemphigoid in clinical remission: a multicenter, prospective, cohort study. Arch 
Dermatol. 2009;145(5):537-542. 
31. Wang Y, Mao X, Wang Y, et al. Relapse of bullous pemphigoid: an update on this 
stubborn clinical problem. Ann Med. 2018;50(3):234-239. 
32. Phan N, Blome C, Fritz F, et al. Assessment of pruritus intensity: prospective study on 
validity and reliability of the visual analogue scale, numerical rating scale, and verbal 
rating scale in 471 patients with chronic pruritus. Acta Derm Venereol. 2012;92(5):502-
507. 
33. Verweyen E, Stander S, Keritz K, et al. Validation of a comprehensive set of pruritus 
assessment instruments: the Chronic Pruritus Tools Questionnaire PRURITOOLS. Acta 
Derm Venereol. 2019;99(7):657-663. 
34. Storck M, Sandmann S, Bruland P, et al. Pruritus intensity scales across Europe: a 
prospective validation study. J Eur Acad Dermatol Venereol. 2021;35(5):1176-1185. 
35. The EuroQol Group. The EQ-5D-5L: About the version. Accessed: 19 Feb 2024. 
https://euroqol.org/information-and-support/euroqol-instruments/eq-5d-5l/ 
36. Finlay AY, Khan GK. Dermatology Life Quality Index (DLQI): a simple practical 
measure for routine clinical use. Clin Exp Dermatol. 1994;19(3)210-216. 
37. Sebaratnam DF, Hanna AM, Chee SN, et al. Development of a quality-of-life instrument 
for autoimmune bullous disease: the Autoimmune Bullous Disease Quality of Life 
questionnaire. JAMA Dermatol. 2013;149(10):1186-1191. 
38. Centers for Disease Control (CDC). Interpretation of hepatitis B serologic test results. 
Accessed: 19 Feb 2024. 
https://www.cdc.gov/hepatitis/hbv/interpretationOfHepBSerologicResults.htm 
39. McDowell PJ, Stone JH, Zhang Y, et al. Quantification of glucocorticoid-associated 
morbidity in severe asthma using the Glucocorticoid Toxicity Index. J Allergy Clin 
Immunol. 2021;9(1):365-372. 
40. Frewer P, Mitchell P, Watkins C, Matcham J. Decision-making in early clinical drug 
development. Pharm Stat. 2016;15(3):255-263. 
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