An Open-label Extension Study of ARGX-113-2009 to Evaluate the Long Term Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC in Adult Participants With Bullous Pemphigoid
Phase: PHASE3
Conditions: Bullous Pemphigoid
Sponsor: argenx

Clinical Protocol ARGX-113-2010 v4.0 
02 May 2024 
Efgartigimod PH20 SC 
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TITLE PAGE 
Protocol Title: 
An Open-label Extension Study of ARGX-113-2009 to Evaluate 
the Long-term Safety, Tolerability, and Efficacy of Efgartigimod 
PH20 SC in Adult Participants With Bullous Pemphigoid 
Protocol Number: 
ARGX-113-2010 
Version Number: 
4.0 (Amendment 3) 
Compound: 
Efgartigimod (ARGX-113) 
Study Phase: 
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): 
EudraCT: 2021-003063-10 
Approval Date: 
02 May 2024 
 
 
 
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Sponsor’s Medical 
Contact: 
, MD 
Global Clinical Trial Physician, Clinical Development 
argenx BV 
Industriepark Zwijnaarde 7 
9052 Zwijnaarde (Ghent) 
Belgium 
Phone: 
 
Email: 
 
Contract Research 
Organization: 
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:  
North America: +1 800 201 8725 
Europe/Asia-Pacific: +44 1223 374240 
Serious Adverse 
Event Reporting: 
Email: safety@argenx.com 
Fax: +1 833 874 7325  
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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SIGNATURE OF THE SPONSOR 
Protocol Title: 
An Open-label Extension Study of ARGX-113-2009 to Evaluate 
the Long-term Safety, Tolerability, and Efficacy of Efgartigimod 
PH20 SC in Adult Participants With Bullous Pemphigoid 
Protocol Number: 
ARGX-113-2010 
Sponsor Signatory: 
 
 
See appended signature page 
 
 
, MD, PhD 
Chief Medical Officer 
 
Date  
 
 
 
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SIGNATURE OF THE INVESTIGATOR 
Investigator’s Acknowledgment 
I have read the protocol for study ARGX-113-2010. 
Title: An Open-label Extension Study of ARGX-113-2009 to Evaluate the Long-term Safety, 
Tolerability, and Efficacy 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 will not be disclosed, except 
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 in order 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 
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 can lead to the 
termination of my participation as an investigator for this study. 
I understand that the sponsor can decide to suspend or prematurely terminate the study at any 
time for any reason; such a decision will be communicated to me in writing. Conversely, if I 
decide to withdraw from execution of the study, I will communicate my intention immediately in 
writing to the sponsor. 
 
 
Investigator Name 
Institution 
Address 
(please handprint or type) 
 
 
 
 
Signature 
 
 
 
Date 
 
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PROTOCOL AMENDMENT SUMMARY OF CHANGES 
Global protocol document history 
Date 
Amendment 3 v4.0 
02 May 2024 
Amendment 2 v3.0 
26 Apr 2024 
Amendment 1 v2.0 
02 Jun 2023 
Original v1.0 
07 Oct 2022 
Amendment 3 (02 May 2024) 
This amendment is considered 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 the Amendment 
The primary rationale for amendment 2 (v3.0, 26 Apr 2024) was to make changes to the 
principles for treatment with efgartigimod for subcutaneous (SC) administration coformulated 
with rHuPH20 (efgartigimod PH20 SC) and concomitant therapies. All participants who initiate 
or continue efgartigimod PH20 SC will now receive it for the duration of the treatment period. 
Efgartigimod PH20 SC may be initiated without concurrent oral corticosteroids, and the 
requirement to stop efgartigimod PH20 SC when participants are in complete remission or partial 
remission while off concurrent bullous pemphigoid (BP) therapy for ≥8 weeks was removed. 
Those changes are implemented to gain better insight into the safety and efficacy of efgartigimod 
PH20 SC in adult participants with BP. 
The reason for amendment 3 (v4.0) is to correct an error in the schedule of activities (Table 2). 
The administration of efgartigimod PH20 SC no longer stops when participants are in complete 
remission or partial remission while off concurrent BP therapy for ≥8 weeks. 
The major changes from the protocol v2.0 to protocol v3.0 and v3.0 to v4.0 are summarized 
in the following table. Added text is indicated with bold font and deleted text by strikethrough 
font. Minor editorial changes are not summarized in the table. Refer to the List of Abbreviations 
and Definitions of Terms for any undefined abbreviations or terms. 
Section 
Change in study conduct or planned 
analysis 
Brief rationale 
Version 4.0 
1.3. Schedule of Activities 
The following change was made in the 
“Efgartigimod PH20 SC administration” 
row of Table 2: 
Once weekly until CR/PR off concurrent 
BP therapy ≥8 weeks 
To align with updated 
design 
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
Version 3.0 
6.3 Assignment to Study 
Intervention 
Other sections impacted are 
Definition of Terms  
1.1 Synopsis 
1.2. Schema 
1.3. Schedule of Activities 
4. Study Design 
 
The study design was modified as 
follows:  
The requirement to stop efgartigimod 
PH20 SC when participants are in CR or 
PR while off concurrent BP therapy for 
≥8 weeks was removed. Guidance was 
added for initiating efgartigimod PH20 
SC without concurrent OCS and tapering 
or discontinuing rescue therapy started 
in ARGX-113-2009.  
IMP will be permanently discontinued if 
the investigator considers it not to be in 
the participant’s best interest to taper or 
discontinue rescue therapy, or initiate 
efgartigimod PH20 SC. 
To gain better insight 
into the safety and 
efficacy of 
efgartigimod PH20 SC 
without concurrent 
OCS or other BP 
therapy, and allow 
evaluation of whether 
maintenance therapy 
with efgartigimod PH20 
SC can prevent relapse 
3. Objectives, Endpoints, and 
Estimands 
Other sections impacted are 
1.1 Synopsis 
The following footnote was added to the 
endpoints “Proportion of participants 
achieving CR while off both OCS and 
efgartigimod PH20 SC for ≥8 weeks” 
and “Proportion of participants 
achieving CR or PR while off both OCS 
and efgartigimod PH20 SC for ≥8 
weeks”: 
The endpoint applies only to 
participants who have stopped 
receiving efgartigimod PH20 SC 
before protocol amendment 2 is 
effective. 
To align with updated 
design 
6.1. Investigational Medicinal 
Product Administered 
The following changes were made in the 
“intervention description” and “dosage 
level(s)” rows of Table 5: 
At the start of a treatment course: 0.2 to 
0.5 mg/kg/day 
Thereafter: Initiated and adjusted 
according to clinical judgment 
 
Concurrent OCS 
therapy is no longer 
required to be started at 
the same time as 
efgartigimod PH20 SC 
initiation 
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
At the start of a treatment course: 0.2 to 
0.5 mg/kg/day 
Thereafter: adjusted according to clinical 
judgment 
6.9. Prior and Concomitant 
Therapy 
The following medications or treatments 
are not permitted during the period when 
the participant is receiving IMP as of 
when the ICF has been signed through 
the completion of the EoTP visit or 
EDV, as applicable: 
 
− Any systemic treatment for BP (eg, 
IV or intramuscular corticosteroids, 
systemic immunosuppressants) 
except for: OCS  
 Concurrent BP therapy started in 
ARGX 113 2009: Participants who 
received rescue therapy in ARGX
113 2009 can maintain, taper, or 
discontinue this treatment according 
to the clinical judgment of the 
investigator (refer to Section 6.3) 
Rescue therapy started 
in ARGX-113-2009 
should now be tapered 
or discontinued 
6.9.1. Oral Prednisone Tapering 
and Escalation 
• 
At enrollment in ARGX 113
2010, participants will continue 
OCS following the tapering 
course used in ARGX 113
2009, if applicable. 
• 
Participants who were 
receiving concurrent OCS in 
ARGX-113-2009 will continue 
their OCS tapering course, as 
outlined in this section. 
• 
New treatment courses with oral 
prednisone may be started at a 
dose of 0.2 to 0.5 mg/kg/day per 
the investigator’s discretion. If 
CDA is not achieved at a dose of 
<0.5 mg/kg/day, it is 
To rely more on the 
investigator’s clinical 
judgment for decisions 
on tapering or 
increasing OCS dosage 
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
recommended to increase to 0.5 
mg/kg/day. 
• 
New treatment courses with 
oral prednisone may be 
initiated if there is a lack of 
clinical improvement in the 
participant's BP disease status 
and additional BP therapy is 
required. The starting dose of 
oral prednisone should be the 
lowest advisable dose and 
must not exceed 0.5 
mg/kg/day. The choice of the 
starting dose within the 
specified range is at the 
investigator's discretion. 
• 
Escalated doses of oral 
prednisone may be considered if 
the participant does not achieve 
CDA within 1 to 3 weeks of 
prednisone at or below 
0.5 mg/kg/day. Participants who 
do not achieve CDA despite 
receiving efgartigimod PH20 SC 
with escalated dosages of OCS 
(0.75 mg/kg/day or higher) will 
be considered treatment failures 
(refer to the Definitions of 
Terms for a full description) and 
IMP will be permanently 
discontinued. 
• When CDA is achieved, the oral 
prednisone dose regimen is adjusted as 
follows based on the investigator's 
clinical judgment. 
Recommendations for tapering are 
as follows: 
− After CDA has been sustained for ≥2 
weeks, the tapering schedule begins 
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
with the next lower oral prednisone 
dosage, as listed in Table 6. 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 Each 
new dosage will be maintained for 
2 weeks or less, based on clinical 
judgment. 
 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 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 from 
this increased dose can start after 
CDA has been sustained for at least 
2 weeks on this increased dose.  
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
− If CDA is not achieved on an 
increased dose, it is recommended to 
return to an oral prednisone dose of 
0.5 mg/kg/day. 
• The OCS dosage may be adjusted 
according to the investigator's 
clinical judgment if disease activity 
occurs during the OCS tapering. 
6.9.2. Rescue Therapy Tapering 
and Discontinuation 
A new section was added to specify how 
rescue therapy started in 
ARGX-113-2009 should be tapered or 
discontinued. 
To align with updated 
design 
7.1.1. Permanent Discontinuation • Investigator considers tapering or 
discontinuing rescue therapy started 
in ARGX-113-2009 not to be in the 
participant’s best interest. 
To align with updated 
design 
1.3. Schedule of Activities (SoA) 
2.3. Benefit/Risk Assessment 
The participant must be monitored for 
safety for at least 30 minutes after 
efgartigimod PH20 SC administration 
when treatment is administered on site. 
 
Monitor participants during 
administration and for at least 30 
minutes thereafter for clinical signs and 
symptoms of infusion/injection related 
reactions when treatment is administered 
on site. Participants for whom 
efgartigimod PH20 SC is administered 
at the site 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. 
To align with the 
current efgartigimod IB 
 
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Section 
Change in study conduct or planned 
analysis 
Brief rationale 
6.2. Preparation, Handling, 
Storage, and Accountability 
In exceptional cases, IMP, other BP 
therapies, and ancillaries may be 
shipped to participants by courier. 
To reduce the travel 
burden on participants  
7.2. Participant 
Discontinuation/Withdrawal 
From the Study 
If the participant also withdraws consent 
to participate in future research, the 
sponsor may retain and continue to use 
any data collected before consent was 
withdrawn.  
The samples collected from participants 
who have withdrawn from the study will 
still be used for the study results 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 the guidance 
on sample use for 
future research 
8.3.5. Pregnancy Testing 
• 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 to12 
months after the baby’s birth. 
To align with the 
current argenx policy 
8.6. Pharmacodynamics 
8.9. Immunogenicity 
Assessments 
(preferably within 2 hours before IMP 
administration) 
To offer flexibility for 
the collection of 
predose blood samples 
 
 
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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 ABBREVIATIONS AND DEFINITIONS OF TERMS ................................................17 
List of Abbreviations .....................................................................................................................17 
Definitions of Terms ......................................................................................................................19 
1. 
PROTOCOL SUMMARY ..........................................................................................21 
1.1. 
Synopsis ......................................................................................................................21 
1.2. 
Schema ........................................................................................................................23 
1.3. 
Schedule of Activities .................................................................................................25 
2. 
INTRODUCTION ......................................................................................................33 
2.1. 
Study Rationale ...........................................................................................................33 
2.2. 
Background .................................................................................................................33 
2.3. 
Benefit/Risk Assessment ............................................................................................34 
2.3.1. 
Risk Assessment .........................................................................................................34 
2.3.2. 
Benefit Assessment .....................................................................................................35 
2.3.3. 
Overall Benefit-Risk Conclusion ................................................................................36 
3. 
OBJECTIVES, ENDPOINTS, AND ESTIMANDS ..................................................37 
4. 
STUDY DESIGN .......................................................................................................39 
4.1. 
Overall Design ............................................................................................................39 
4.2. 
Scientific Rationale for Study Design ........................................................................39 
4.3. 
Justification for Dose ..................................................................................................40 
4.4. 
End-of-the-Study Definition .......................................................................................40 
5. 
STUDY POPULATION .............................................................................................41 
5.1. 
Inclusion Criteria ........................................................................................................41 
5.2. 
Exclusion Criteria .......................................................................................................41 
5.3. 
Lifestyle Considerations .............................................................................................41 
5.4. 
Screen Failures ............................................................................................................41 
5.5. 
Criteria for Temporarily Delaying Enrollment/IMP Administration .........................41 
6. 
STUDY INTERVENTION(S) AND CONCOMITANT THERAPY ........................42 
6.1. 
Investigational Medicinal Product Administered .......................................................42 
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6.2. 
Preparation, Handling, Storage, and Accountability ..................................................43 
6.3. 
Assignment to Study Intervention ..............................................................................44 
6.3.1. 
Participants Who Roll Over After Protocol Amendment 2 Is Effective ....................44 
6.3.2. 
Participants Who Are Ongoing in This Study When Protocol Amendment 2 
Is Effective ..................................................................................................................45 
6.4. 
Blinding ......................................................................................................................45 
6.5. 
Study Compliance .......................................................................................................45 
6.6. 
Dose Modification ......................................................................................................46 
6.7. 
Continued Access to IMP After the End of the Study ................................................46 
6.8. 
Treatment of Overdose ...............................................................................................46 
6.9. 
Prior and Concomitant Therapy ..................................................................................46 
6.9.1. 
Oral Prednisone Tapering and Escalation ...................................................................47 
6.9.2. 
Rescue Therapy Tapering and Discontinuation ..........................................................50 
7. 
IMP DISCONTINUATION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL ..................................................................51 
7.1. 
IMP Discontinuation ...................................................................................................51 
7.1.1. 
Permanent Discontinuation .........................................................................................51 
7.1.2. 
Temporary Discontinuation ........................................................................................52 
7.2. 
Participant Discontinuation/Withdrawal From the Study ...........................................52 
7.3. 
Lost to Follow-up .......................................................................................................53 
8. 
STUDY ASSESSMENTS AND PROCEDURES ......................................................54 
8.1. 
Administrative and General/Baseline Procedures ......................................................54 
8.1.1. 
Use and Storage of Biological Samples ......................................................................54 
8.2. 
Efficacy Assessments .................................................................................................54 
8.2.1. 
Efficacy Measures ......................................................................................................55 
8.2.1.1. 
Assessment of BP Disease Status and OCS Dose Monitoring ...................................55 
8.2.1.2. 
Investigator Global Assessment of Bullous Pemphigoid ...........................................55 
8.2.1.3. 
Bullous Pemphigoid Disease Area Index ...................................................................55 
8.2.1.4. 
Itch Numerical Rating Scale .......................................................................................55 
8.2.2. 
Quality of Life Assessments .......................................................................................55 
8.2.2.1. 
EQ-5D-5L ...................................................................................................................55 
8.2.2.2. 
Dermatology Life Quality Index ................................................................................56 
8.2.2.3. 
Autoimmune Bullous Disease Quality of Life Index .................................................56 
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8.3. 
Safety Assessments .....................................................................................................56 
8.3.1. 
Vital Signs ..................................................................................................................56 
8.3.2. 
Physical Examinations ................................................................................................56 
8.3.3. 
Electrocardiograms .....................................................................................................56 
8.3.4. 
Protocol-Required Laboratory Tests...........................................................................56 
8.3.4.1. 
Substudy—Vaccination Response ..............................................................................57 
8.3.5. 
Pregnancy Testing ......................................................................................................57 
8.3.6. 
Glucocorticoid Toxicity Index ....................................................................................57 
8.3.7. 
Infections and Vaccinations ........................................................................................58 
8.3.8. 
Suicidal Ideation and Behavior Monitoring ...............................................................59 
8.4. 
Adverse Events, Serious Adverse Events, and Other Safety Reporting .....................59 
8.4.1. 
Time Period and Frequency for Collecting AE and SAE Information .......................59 
8.4.2. 
Method of Detecting AEs and SAEs ..........................................................................60 
8.4.3. 
Follow-up of AEs and SAEs .......................................................................................60 
8.4.4. 
Regulatory Reporting Requirements for SAEs ...........................................................60 
8.4.5. 
Pregnancy ...................................................................................................................60 
8.4.6. 
AESIs ..........................................................................................................................61 
8.4.7. 
AEs of Clinical Interest ..............................................................................................61 
8.4.7.1. 
Infusion/Injection-Related Reactions .........................................................................61 
8.4.7.2. 
Injection Site Reactions ..............................................................................................61 
8.5. 
Pharmacokinetics ........................................................................................................62 
8.6. 
Pharmacodynamics .....................................................................................................62 
8.7. 
Genetics ......................................................................................................................62 
8.8. 
Biomarkers ..................................................................................................................62 
8.9. 
Immunogenicity Assessments ....................................................................................62 
8.10. 
Health Economics and Medical Resource Utilization ................................................63 
9. 
STATISTICAL CONSIDERATIONS .......................................................................64 
9.1. 
Statistical Hypotheses .................................................................................................64 
9.2. 
Analysis Sets ...............................................................................................................64 
9.3. 
Statistical Analyses .....................................................................................................64 
9.3.1. 
General Considerations ...............................................................................................64 
9.4. 
Interim Analysis ..........................................................................................................65 
9.5. 
Sample Size Determination ........................................................................................65 
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10. 
SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS ..................................................................................................66 
10.1. 
Appendix 1: Regulatory, Ethical, and Study Oversight Considerations ....................66 
10.1.1. 
Regulatory and Ethical Considerations ......................................................................66 
10.1.2. 
Financial Disclosure ...................................................................................................66 
10.1.3. 
Informed Consent Process ..........................................................................................67 
10.1.4. 
Recruitment Strategy ..................................................................................................67 
10.1.5. 
Data Protection ...........................................................................................................67 
10.1.6. 
Committees Structure .................................................................................................68 
10.1.7. 
Dissemination of Clinical Study Data ........................................................................68 
10.1.8. 
Data Quality Assurance ..............................................................................................68 
10.1.9. 
Source Documents ......................................................................................................69 
10.1.10. 
Study and Site Start and Closure ................................................................................69 
10.1.11. 
Publication Policy .......................................................................................................70 
10.2. 
Appendix 2: Clinical Laboratory Tests .......................................................................71 
10.3. 
Appendix 3: AEs and SAEs: Definitions and Procedures for Recording, 
Evaluating, Follow-up, and Reporting ........................................................................72 
10.3.1. 
Definition of AE .........................................................................................................72 
10.3.2. 
Definition of SAE .......................................................................................................73 
10.3.3. 
Recording and Follow-up of AE and/or SAE .............................................................73 
10.3.4. 
Reporting of SAEs and AESIs ....................................................................................75 
10.4. 
Appendix 4: Contraceptive and Barrier Guidance ......................................................76 
10.4.1. 
Women of Childbearing Potential Definition .............................................................76 
10.4.2. 
Contraception Guidance .............................................................................................76 
10.4.2.1. 
Female Contraception for WOCBP ............................................................................76 
10.4.2.2. 
Male Contraception ....................................................................................................77 
10.5. 
Appendix 5: Operational Considerations for COVID-19 Risk Mitigation .................78 
10.6. 
Appendix 6: Protocol Amendment History ................................................................80 
10.7. 
Appendix 7: Country-specific Requirements .............................................................87 
10.7.1. 
China ...........................................................................................................................87 
11. 
REFERENCES ...........................................................................................................90 
 
 
 
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LIST OF TABLES 
Table 1: 
Schedule of Activities for Participants Who Have Not Received 
Efgartigimod PH20 SC Since Baseline and Rolled Over Before Protocol 
Amendment 2 Is Effective ..........................................................................................25 
Table 2: 
Schedule of Activities for Participants Who Roll Over or Initiate 
Efgartigimod PH20 SC After Protocol Amendment 2 Is Effective, and 
Participants Who Stopped Receiving Efgartigimod PH20 SC After Roll 
Over but Before Protocol Amendment 2 Is Effective ................................................28 
Table 3: 
Potential Risks and Mitigation Strategies ...................................................................34 
Table 4: 
Study ARGX-113-2010 Objectives and Endpoints ....................................................37 
Table 5: 
Study Intervention(s) Administered ...........................................................................42 
Table 6: 
Concurrent Oral Prednisone Equivalent Doses (in mg) Based on Participant 
Body Weight ...............................................................................................................49 
Table 7: 
Protocol-Required Laboratory Tests...........................................................................71 
Table 8: 
Scheme for Study Visits Performed at Home During COVID-19 Pandemic .............78 
Table 9: 
Concurrent Oral Methylprednisolone Equivalent Doses (in mg) Based on 
Participant Body Weight .............................................................................................88 
 
LIST OF FIGURES 
Figure 1: 
ARGX-113-2010 Study Overview .............................................................................23 
 
 
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LIST OF ABBREVIATIONS AND DEFINITIONS OF TERMS 
List of Abbreviations 
Abbreviation 
Expansion 
21 CFR 
Title 21 of the Code of Federal Regulations 
ABQoL 
Autoimmune Bullous Disease Quality of Life 
ADA 
antidrug antibody(ies) 
ADL 
activities of daily living 
AE 
adverse event 
AESI 
adverse event of special interest 
AIBD 
autoimmune blistering disease 
ALT 
alanine aminotransferase 
AST 
aspartate aminotransferase 
BP 
bullous pemphigoid 
BPDAI 
Bullous Pemphigoid Disease Area Index 
CDA 
control of disease activity 
C-GTI 
Composite Glucocorticoid Toxicity Index 
CR 
complete remission 
CTCAE 
Common Terminology Criteria for Adverse Events 
CTFG 
Clinical Trials Facilitation and Coordination Group 
DLQI 
Dermatology Life Quality Index 
eCRF 
electronic case report form 
EDV 
early discontinuation visit 
efgartigimod 
PH20 SC 
efgartigimod for SC administration coformulated with rHuPH20 
EoTP 
end-of-treatment period 
FcRn 
neonatal crystallizable fragment receptor 
FSH 
follicle-stimulating hormone 
GCP 
Good Clinical Practice 
gMG 
generalized myasthenia gravis 
GTI 
Glucocorticoid Toxicity Index 
GTI-AIS 
GTI Aggregate Improvement Score 
GTI-CWS 
GTI Cumulative Worsening Score 
GTI-SL 
GTI Specific List 
HGRAC 
Human Genetic Resources Administration of China 
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Abbreviation 
Expansion 
IB 
Investigator’s Brochure 
ICF 
informed consent form 
ICH 
International Council for Harmonisation of Technical Requirements for 
Pharmaceuticals for Human Use 
IEC/IRB 
independent ethics committee/institutional review board 
IGA-BP 
Investigator Global Assessment of Bullous Pemphigoid 
IgG 
immunoglobulin γ 
IMP 
investigational medicinal product 
ITP 
immune thrombocytopenia 
IV 
intravenous(ly) 
MedDRA 
Medical Dictionary for Regulatory Activities 
NCI 
National Cancer Institute 
NRS 
numerical rating scale 
OCS 
oral corticosteroids 
OLE 
open-label extension 
PD 
pharmacodynamic(s) 
PR 
partial remission 
PRO 
participant-reported outcome 
PT 
Preferred Term 
QoL 
quality of life 
QTL 
quality tolerance limit 
rHuPH20 
recombinant human hyaluronidase PH20 
SAE 
serious adverse event 
SAP 
statistical analysis plan 
SC 
subcutaneous(ly) 
SoA 
schedule of activities 
SOC 
System Organ Class 
SUSAR 
suspected unexpected serious adverse reaction 
TCS 
topical corticosteroids 
ULN 
upper limit of normal 
WOCBP 
women of childbearing potential 
 
 
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Definitions of Terms 
• Efgartigimod PH20 SC 
Efgartigimod for SC administration coformulated with rHuPH20 
• Concurrent BP therapy 
Therapy administered in this study for the treatment of BP other than 
efgartigimod PH20 SC. This may include: 
• Rescue therapy administered in ARGX-113-2009 
• OCS 
• TCS 
• Stop of efgartigimod 
PH20 SC 
Occurs when the participant stops receiving efgartigimod PH20 SC after 
achieving CR or PR off concurrent BP therapy for ≥8 weeks. 
Only applicable before protocol amendment 2 was effective. 
• Discontinuation of 
efgartigimod PH20 SC 
Occurs when the participant stops receiving efgartigimod PH20 SC before 
the end of the study for reasons other than achieving CR or PR off 
concurrent BP therapy for ≥8 weeks (refer to Section 7.1)  
 
The following definitions are based on consensus definitions (Murrell et al, 20121) and will be applied 
in ARGX-113-2010: 
• 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 despite receiving efgartigimod PH20 SC with 
escalated dosages of prednisone (or equivalent OCS)  
Escalated dosages of OCS are defined as prednisone (or equivalent OCS) 
0.5 mg/kg/day for 1 to 3 weeks, followed by 0.75 mg/kg/day for 
≤3 weeks, and 0.75 or 1.0 mg/kg/day for a final optional week.  
• Transient lesions  
New lesions that heal within 1 week or pruritus lasting <1 week 
• Nontransient lesions 
New lesions that do not heal within 1 week or pruritus continuing >1 week 
• Minimal OCS therapy  
An oral prednisone (or equivalent OCS) dosage of ≤0.10 mg/kg/day  
Note: For the purpose of this protocol, “oral prednisone” refers to 
doses/dosages of prednisone or an alternative, equivalent OCS (eg, 
prednisolone). 
• Complete remission 
(CR) 
The absence of new lesions, complete healing of existing lesions, and 
absence of pruritus (except postinflammatory changes, including 
hypo/hyper pigmentation or skin damage) 
• Partial remission (PR) 
The presence of only new transient lesions 
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• Sustained remission 
For participants ongoing in the study when protocol amendment 2 is 
effective: 
Healing of lesions with no nontransient lesions (ie, BPDAI activity 
score of 0) and absence of pruritus while the participant has been off 
both concurrent BP therapy and off efgartigimod PH20 SC for 
≥8 weeks 
New lesions that heal within 1 week or pruritus lasting <1 week and 
clearing without treatment will not be considered to change the 
condition of sustained remission. 
For participants rolling over after protocol amendment 2 is effective: 
Healing of lesions with no nontransient lesions (ie, BPDAI activity 
score of 0) and absence of pruritus while the participant has been off 
concurrent BP therapy for ≥8 weeks.  
New lesions that heal within 1 week or pruritus lasting <1 week and 
clearing without treatment will not be considered to change the 
condition of sustained remission. 
• Relapse 
Appearance of 3 or more new lesions/month (blisters, eczematous lesions, 
or urticarial plaques) or at least 1 large (>10 cm diameter) eczematous 
lesion or urticarial plaque that does not heal within 1 week, or extension of 
established lesions or daily pruritus in a participant who has achieved 
CDA. 
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1. 
PROTOCOL SUMMARY 
1.1. 
Synopsis 
Protocol Title: An Open-label Extension Study of ARGX-113-2009 to Evaluate the Long-term 
Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC in Adult Participants With Bullous 
Pemphigoid 
Rationale: This OLE study will assess whether long-term administration of efgartigimod PH20 SC 
is safe and effective in adults with BP who participated in ARGX-113-2009 (a phase 2/3 study of 
efgartigimod PH20 SC in adult participants with BP). 
Objectives, Endpoints, and Estimands:  
Objectives 
Endpoints 
Primary 
To assess the long-term safety and 
tolerability of treatment with 
efgartigimod PH20 SC in participants 
with BP 
• Incidence and severity of treatment-emergent AEs, SAEs, 
and AESIs  
• Rate of treatment discontinuation because of safety 
concerns 
Secondary 
To assess the long-term efficacy and 
durability of response with efgartigimod 
PH20 SC treatment in participants with 
BP  
• 
Proportions of participants achievinga: 
− CR while off OCS for ≥8 weeks 
− CR or PR while off OCS for ≥8 weeks 
− CR while on minimal OCS therapy for ≥8 weeks. 
(Minimal OCS therapy is defined as ≤0.10 mg/kg/day 
of prednisone [or an equivalent dose of another OCS]) 
− CR while off both OCS and efgartigimod PH20 SC for 
≥8 weeksb 
− CR or PR while off both OCS and efgartigimod PH20 
SC for ≥8 weeksb 
• 
Duration of sustained remission 
• 
Proportion of participants who relapse  
• 
Time to relapse  
• 
Incidence and severity of relapse  
• 
BPDAI activity scores, IGA-BP scores, and itch NRS 
over time 
• 
Rate of treatment failure 
a These endpoint criteria can only be met when participants are off rescue therapy. 
b The endpoint applies only to participants who have stopped receiving efgartigimod PH20 SC before protocol 
amendment 2 is effective. 
No estimands have been defined for this OLE study. 
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Overall Design: This is a phase 3, prospective, global, multicenter, OLE study to investigate the 
long-term safety, tolerability, efficacy, QoL, PD, and immunogenicity of efgartigimod PH20 SC in 
adult participants with BP who have completed ARGX-113-2009. The study will be conducted 
globally, at the same sites as ARGX-113-2009. 
In ARGX-113-2009, participants received efgartigimod PH20 SC or placebo with concurrent 
OCS, or rescue therapy (without efgartigimod PH20 SC or placebo). When rolling over to 
ARGX-113-2010, participants will either initiate or continue efgartigimod PH20 SC treatment, 
while maintaining the blinded treatment allocation of ARGX-113-2009 (refer to Section 6.4). 
Before protocol amendment 2, participants had to stop receiving efgartigimod PH20 SC upon 
achieving CR or PR while off concurrent BP therapy for ≥8 weeks. After protocol amendment 2, 
participants who stopped efgartigimod PH20 SC will reinitiate treatment at the investigator’s 
discretion. If they relapse, reinitiation of efgartigimod PH20 SC treatment is mandatory. All 
other participants (ongoing and newly enrolled) will continue to receive efgartigimod PH20 SC 
until the end of the treatment period. Concurrent BP therapies, including rescue therapies started 
during ARGX-113-2009, will be tapered or discontinued. IMP will be permanently discontinued 
if the investigator considers it not to be in the participant’s best interest to taper or discontinue 
rescue therapy or initiate efgartigimod PH20 SC. 
Brief Summary: The purpose of this study is to evaluate the safety of efgartigimod PH20 SC over a 
longer period of time in adult participants with moderate-to-severe BP. The study will also evaluate 
the efficacy of efgartigimod PH20 SC. 
Health Measurement/Outcome: The primary outcome measure is the long-term safety and 
tolerability of open-label efgartigimod PH20 SC for approximately 1 year after completing 
ARGX-113-2009.  
Investigational Medicinal Product and Investigational Medicinal Product Formulation: 
Efgartigimod PH20 SC 
 
 
Condition/Disease: Bullous pemphigoid 
Study Duration: Approximately 56 weeks 
Treatment Duration: Up to 48 weeks 
Visit Frequency: Participants will visit the site at weeks 0 (baseline), 1, 2, 4, and 8. After that, 
participants will visit every 4 weeks. Participants not receiving efgartigimod PH20 SC will visit 
every 8 weeks. A treatment-free period of 8 weeks follows the EoTP visit at week 48, with visits at 
EoTP + 4 weeks (if receiving efgartigimod PH20 SC) and EoTP + 8 weeks. 
Number of Participants: All participants who complete the EoTP visit (week 36) in 
ARGX-113-2009 and meet the eligibility criteria can roll over to this study. All participants rolling 
over agree to participate in the clinical study by completing the informed consent process. 
Study Arms and Duration: This is a single-arm study comprising a 48-week treatment period and a 
follow-up period of 8 weeks. 
Data Monitoring/Other Committee: No 
Ethical Considerations: The potential risks associated with efgartigimod PH20 SC are justified 
by the anticipated benefits that may be afforded to participants with BP in this study. 
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c Participants who stopped receiving efgartigimod PH20 SC after rollover but before protocol amendment 2 is effective will enter the observation period with 
visits every 8 weeks. Efgartigimod PH20 SC will be initiated at the investigator’s discretion or if relapse occurs during the study. Participants who initiate 
efgartigimod PH20 SC must follow the SoA in Table 2 as of day X (refer to Section 6.3 for more details). 
d Visit F1 (EoTP + 4 weeks) is only applicable for participants receiving efgartigimod PH20 SC at week 48.  
e When a participant permanently discontinues IMP and/or is withdrawn from the study during the treatment period, study sites should attempt to perform the 
EDV within 7 days after the participant’s final IMP administration and safety follow-up visits 4 and 8 weeks after the participant’s final IMP administration. If 
a participant is withdrawn from the study during the observation period, refer to the SoA in Table 1. 
f A UNS may be performed if the participant has (or suspects they have) new BP lesions or other issues requiring site staff intervention, such as notable weight 
change. At these visits, the investigator will determine whether efgartigimod PH20 SC therapy must be started/resumed and will decide which assessments to 
conduct based on the purpose of the UNS. If relapse occurs, IGA-BP, BPDAI, and itch NRS assessments must be performed. 
g A brief physical examination should be performed instead of a complete examination if the participant had a complete physical examination ≤4 weeks before 
day X. 
h Brief physical examinations, GTI, and QoL will be assessed every 16 weeks relative to the last performed assessment. WOCBP will have urine pregnancy tests 
every 4 weeks relative to the last performed assessment. 
i If the time point of the assessment does not coincide with a planned on-site visit, the assessment should be performed at the next on-site visit. 
j Weight must be measured only if the participant is being administered OCS. 
k The urine pregnancy test is only applicable for WOCBP. The pregnancy test at the F2 visit is only applicable for participants on efgartigimod PH20 SC at 
EoTP/EDV. 
l Efgartigimod PH20 SC will be administered once weekly.
 (on days 1 and 8 of treatment) and weekly maintenance doses of 1000 mg 
will be used. Refer to Section 6.3 for more information and to Section 6.5 for information about (self-)administration. Week 48 is the last time point that 
participants may receive doses of efgartigimod PH20 SC. 
m Participants and/or their caregivers will be invited to receive at least 1 refresher training course for efgartigimod PH20 SC (self-)administration. Training may 
continue or be repeated until the participant (or caregiver) is considered capable of performing the (self-)administration. 
 
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2. 
INTRODUCTION 
ARGX-113-2010 intends to demonstrate that efgartigimod PH20 SC is a safe and effective 
long-term treatment for BP, providing symptom control and eventually remission, while also 
reducing the cumulative exposure to OCS. Additionally, the study will evaluate if long-term 
treatment with efgartigimod PH20 SC can prevent relapse. 
2.1. 
Study Rationale 
Efgartigimod is a first-in-class antibody fragment that binds to FcRn. This binding prevents 
FcRn from recycling IgG and leads to a reduction in circulating disease-causing autoantibodies. 
Efgartigimod has been approved by the US Food and Drug Administration for use in adult 
patients with acetylcholine receptor antibody-seropositive gMG, and is also being clinically 
developed in other autoimmune diseases mediated by pathogenic IgG autoantibodies.  
Efgartigimod may be a viable treatment option for individuals with BP, an autoimmune disease 
mediated by IgG autoantibodies, because it has been shown to reduce IgG levels, including IgG 
autoantibodies.  
2.2. 
Background 
BP is a subepidermal AIBD that predominantly affects older adults. It is a chronic disease that 
significantly affects 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 result in direct interference of 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.2,3  
At this time, no results from registrational clinical studies with therapies specifically developed 
for the treatment of patients with BP are available. The current standard of care for BP is 
treatment with 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, 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.4,5,6  
In summary, there is currently an unmet medical need for new BP treatments that provide rapid 
CDA and remission, minimize or prevent relapse, and reduce the burdens placed on patients 
caused by cumulative corticosteroid exposure. This OLE study aims to evaluate the safety, 
tolerability, long-term efficacy, immunogenicity, PRO measures, and PD of efgartigimod PH20 
SC in adult participants with BP, who completed the antecedent study ARGX-113-2009. 
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A detailed description of the chemistry, pharmacology, efficacy, and safety of efgartigimod 
PH20 SC is provided in the current IB.  
2.3. 
Benefit/Risk Assessment 
More detailed information about the known and expected benefits and risks and reasonably 
expected AEs of efgartigimod PH20 SC is provided in the current IB. 
2.3.1. 
Risk Assessment 
Overall, available data confirm that efgartigimod—both as an IV formulation and as 
efgartigimod PH20 SC—has been well tolerated across studies in different indications and has an 
acceptable safety profile.  
Table 3 lists the potential risks that may be encountered in the study and the associated strategies 
to mitigate these risks. 
Table 3: 
Potential Risks and Mitigation Strategies 
Potential clinically 
significant risk  
Summary of data/rationale for risk 
Mitigation strategy 
Serious infection 
Efgartigimod reduces IgG levels, 
potentially hindering immune response 
and increasing the risk for infection. 
Exclude participants with 
clinically significant active 
infection not sufficiently resolved 
in the investigator’s opinion 
(Section 5.2).  
Infections are considered AESIs 
(Section 8.4.6). Monitor for 
infections and temporarily 
interrupt IMP dosing as specified 
in Section 7.1. 
Recommendations for measures 
before and during the study are 
provided in Section 8.3.7. 
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 an 
infusion/injection-related reaction is not 
required. 
 
Participants for whom 
efgartigimod PH20 SC is 
administered at the site 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 8.4.7). 
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Potential clinically 
significant risk  
Summary of data/rationale for risk 
Mitigation strategy 
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 have 
been observed in studies with 
efgartigimod and PH20 and administered 
SC 
Continuously monitor participants 
for injection site reactions when 
treatment is administered on-site. 
Injection site reactions are 
considered AEs of clinical 
interest (Section 8.4.7). 
Potential 
complications from 
exposure to OCS 
OCS are considered a first-line therapy 
for patients with moderate-to-severe BP; 
however, these drugs cause various 
adverse side effects. Therefore, a 
therapeutic goal in the treatment of 
patients with BP is a reduction in OCS 
exposure.  
Rapidly taper OCS doses based 
on the clinical status of the 
participant (Section 6.3). 
Continuously monitor safety, 
including glucocorticoid-
mediated toxicity, throughout the 
study (Section 8.3.6). 
Provide prophylactic and 
supportive care to diminish the 
expected side effects of OCS (ie, 
antiosteoporotic treatments, 
calcium supplements and vitamin 
D) are allowed in the study. 
Older adult 
population 
Patients with BP are typically older adults 
who can have comorbidities that result in 
a general poorer condition compared to 
the general population.  
The investigator will assess if it is 
appropriate for the participant to 
be included in the study 
(Section 5.2, criterion 1).  
AE=adverse event; AESI=adverse event of special interest; BP=bullous pemphigoid; efgartigimod 
PH20 SC=efgartigimod for SC administration coformulated with rHuPH20; IgG=immunoglobulin gamma; 
OCS=oral corticosteroid; rHuPH20=recombinant human hyaluronidase PH20; SC=subcutaneous 
2.3.2. 
Benefit Assessment 
Efgartigimod—either as an IV formulation or as efgartigimod PH20 SC—has been investigated 
in nonclinical studies, phase 1 clinical pharmacology studies in healthy participants, and 
phase 2-3 clinical studies in patients with IgG-driven autoimmune diseases, including gMG, 
primary ITP, chronic inflammatory demyelinating polyneuropathy, myositis, and pemphigus.  
In clinical studies, efgartigimod effectively reduced IgG antibody levels, including pathogenic 
autoantibodies. The efficacy of efgartigimod to improve clinical outcomes in gMG and reduce 
pathogenic autoantibodies was confirmed in a pivotal phase 3 study in participants with gMG 
(ARGX-113-1704). In addition, clinical benefit was observed in a phase 2 study in primary ITP 
(ARGX-113-1603), in which pathogenic autoantibodies underlie the disease pathology (refer to 
the current efgartigimod IB). The available clinical data support the clinical benefit of 
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efgartigimod for reducing pathogenic IgG autoantibodies in participants with autoimmune 
diseases mediated by IgG autoantibodies, such as BP, which may result in clinical or even 
sustained remission.  
In this study, efgartigimod PH20 SC can be administered alone or in combination with OCS. 
When efgartigimod PH20 SC is administered in combination with OCS, rapid OCS tapering 
based on the participant's clinical status will reduce the risks associated with those medications, 
especially high doses of OCS administered in the older adult study population, which is 
especially prone to comorbidities. 
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-113-2010. 
More detailed information about the known and expected benefits and risks of efgartigimod, both 
as an IV formulation and as efgartigimod PH20 SC, and reasonably expected AEs is provided in 
the current IB. 
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3. 
OBJECTIVES, ENDPOINTS, AND ESTIMANDS 
Table 4: 
Study ARGX-113-2010 Objectives and Endpoints 
Objectives 
Endpoints 
Primary 
To assess the long-term safety and 
tolerability of treatment with efgartigimod 
PH20 SC in participants with BP 
• Incidence and severity of treatment-emergent AEs, 
SAEs, and AESIs  
• Rate of treatment discontinuation because of safety 
concerns 
Secondary 
To assess the long-term efficacy and 
durability of response with efgartigimod 
PH20 SC treatment in participants with BP  
• Proportions of participants achievinga: 
− CR while off OCS for ≥8 weeks 
− CR or PR while off OCS for ≥8 weeks 
− CR while on minimal OCS therapy for ≥8 weeks. 
(Minimal OCS therapy is defined as 
≤0.10 mg/kg/day of prednisone [or an equivalent 
dose of another OCS]) 
− CR while off both OCS and efgartigimod PH20 SC 
for ≥8 weeksb 
− CR or PR while off both OCS and efgartigimod 
PH20 SC for ≥8 weeksb  
• Duration of sustained remission 
• Proportion of participants who relapse  
• Time to relapse  
• Incidence and severity of relapse  
• BPDAI activity scores, IGA-BP scores, and itch NRS 
over time 
• Rate of treatment failure 
Additional secondary  
To evaluate the impact of efgartigimod 
PH20 SC treatment in reducing long-term 
glucocorticoid-associated toxicity in 
participants with BP 
GTI-related scores, including the GTI-AIS, GTI-CWS, 
and GTI-SL over time 
To evaluate the impact of efgartigimod 
PH20 SC treatment on QoL in participants 
with BP 
EQ-5D-5L, DLQI, and ABQoL scores over time 
To evaluate the PD and immunogenicity of 
efgartigimod PH20 SC in participants with 
BP 
• Percent change from baseline over time for 
anti-BP180 and anti-BP230 antibody levels 
• Incidence and prevalence of ADA against 
efgartigimod (serum levels) 
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Objectives 
Endpoints 
Exploratory 
 
 
 
 
a These endpoint criteria can only be met when participants are off rescue therapy. 
b The endpoint applies only to participants who have stopped receiving efgartigimod PH20 SC before protocol 
amendment 2 is effective. 
No estimands have been defined for this OLE study. 
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4. 
STUDY DESIGN 
4.1. 
Overall Design 
This is a phase 3, open-label, prospective, global, multicenter, OLE study.  
The total study duration is approximately 56 weeks comprising a treatment period of up to 
48 weeks and a follow-up of approximately 8 weeks.  
The study population is adult patients with BP who have completed ARGX-113-2009.  
At rollover, all participants will receive efgartigimod PH20 SC after this amendment is effective. 
The treatment allocation of ARGX-113-2009 will remain blinded (refer to Section 6.4). 
Participants who received placebo in ARGX-113-2009 and participants who have reinitiated 
efgartigimod PH20 SC treatment will receive 
 of efgartigimod PH20 SC 
 
(on days 1 and 8) followed by once-weekly maintenance doses of efgartigimod PH20 SC1000 
mg.  
Participants who received efgartigimod PH20 SC in ARGX-113-2009 will continue to receive 
once-weekly efgartigimod PH20 SC 1000 mg maintenance doses.  
In the previous protocol version (v2.0), participants had to stop receiving efgartigimod PH20 SC 
after achieving CR or PR while off concurrent BP therapy for ≥8 weeks. For these participants, 
reinitiation of efgartigimod PH20 SC treatment will be at the investigator’s discretion unless the 
participant relapses. Participants who relapse will initiate efgartigimod PH20 SC treatment (more 
details are provided in Section 6.3). 
Participants will visit the site at weeks 0 (baseline), 1, 2, 4, and 8. Thereafter, participants will 
attend site visits every 4 weeks. Participants not receiving efgartigimod PH20 SC will attend site 
visits every 8 weeks. 
The OLE study will remain open in all countries for a maximum of 2 years after completion of 
ARGX-113-2009. 
4.2. 
Scientific Rationale for Study Design 
This is an open-label study to evaluate the long-term safety, tolerability, efficacy, QoL, PD, and 
immunogenicity of efgartigimod PH20 SC in adult participants with BP who have completed 
ARGX-113-2009, and to evaluate whether participants can achieve sustained remission after 
stopping efgartigimod PH20 SC treatment. 
This study provides the option to all eligible participants to continue (ARGX-113-2009 
efgartigimod PH20 SC arm) or initiate (ARGX-113-2009 placebo arm) efgartigimod PH20 SC. 
Participants who discontinued IMP (efgartigimod PH20 SC or placebo) and required rescue 
therapy in ARGX-113-2009 are eligible for this study. They will initiate efgartigimod PH20 SC, 
and rescue therapy will be tapered or discontinued (refer to Section 6.9.2). IMP will be 
permanently discontinued if the investigator considers it not to be in the participant’s best 
interest to taper or discontinue rescue therapy or initiate efgartigimod PH20 SC. 
Measures are in place to ensure the blinded allocation (efgartigimod PH20 SC or placebo) from 
ARGX-113-2009 is maintained (Section 6.3 and Section 6.4). 
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The primary outcome measure is the ongoing safety and tolerability of open-label efgartigimod 
PH20 SC for approximately 1 year (long-term) after completing ARGX-113-2009. The 
endpoints aim to demonstrate that efgartigimod PH20 SC is a safe long-term treatment option for 
BP. The safety and tolerability endpoints for this study are considered to be standard for any 
clinical study evaluating the safety of an IMP. 
Secondary endpoints aim to demonstrate that efgartigimod PH20 SC treatment can provide 
symptom control and eventually remission for patients with BP, while also reducing the 
cumulative exposure to OCS. These endpoints are in line with the efficacy endpoints in 
ARGX-113-2009 and are selected based on the disease terminology described by Murrell et al 
(2012).1  
4.3. 
Justification for Dose 
In ARGX-113-2010, efgartigimod will be administered as SC injections because they are easier 
to administer than IV infusions and offer convenience for participants with BP, their caregivers, 
and health care providers. Additionally, the coformulation of efgartigimod with rHuPH20 
permits SC dosing of higher volumes than typical SC injections with limited skin swelling or 
pain. 
The dosing regimens in ARGX-113-2010 follow the same principles as in ARGX-113-2009. In 
ARGX-113-2009, participants in the efgartigimod PH20 SC arm received 
 of 
 (on days 1 and 8 of treatment) followed by maintenance doses of 1000 mg. The 
regimen aimed to achieve a nearly maximal reduction in total IgG serum levels at the start of the 
treatment followed by a convenient maintenance dose equivalent to a weekly dose of 
efgartigimod IV 10 mg/kg which has proven efficacy in the treatment of other autoimmune 
diseases (gMG and ITP). For more information, refer to the current efgartigimod IB. 
Treatment allocation in ARGX-113-2009 will remain blinded in ARGX-113-2010 until the 
database lock of ARGX-113-2009 (refer to Section 6.4).  
Efgartigimod PH20 SC can be provided in combination with tapering courses of concurrent BP 
therapy (Definitions of Terms) to reduce the risks associated with those medications, especially 
high doses of OCS, in the older adult participant study population who are especially prone to 
comorbidities. 
4.4. 
End-of-the-Study Definition 
The end of the study is defined as the date of the last participant’s last visit. 
A participant is considered to have completed the study if the follow-up visit at EoTP + 8 weeks 
has been completed. 
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5. 
STUDY POPULATION 
Prospective approvals of protocol deviations to 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. Has completed the week 36 visit of ARGX-113-2009 
2. Is capable of providing signed informed consent, as described in Section 10.1.3, and 
complying with protocol requirements 
3. 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 urine pregnancy test at 
baseline before receiving IMP. (Section 10.4.2.1)  
5.2. 
Exclusion Criteria  
Participants will be excluded from the study if any of the following criteria apply: 
1. Clinically significant disease, recent major surgery (within 3 months of baseline), or 
intention to have surgery during the study; or any other medical condition that, in the 
investigator’s opinion, would confound the results of the study or put the participant at 
undue risk 
2. Known hypersensitivity to IMP or 1 of its excipients 
3. Permanently discontinued IMP in ARGX-113-2009 due to an AE considered related to 
IMP and for whom the benefit/risk balance is not considered positive 
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 
Not applicable. 
5.5. 
Criteria for Temporarily Delaying Enrollment/IMP Administration  
If IMP was temporarily interrupted at the time of the week 36/EoTP visit in ARGX-113-2009 
(because of any reason as described in the ARGX-113-2009 protocol), participants can roll over 
to ARGX-113-2010 and have to follow the SoA per Table 1 until the investigator has determined 
that it is safe for the participant to receive treatment. If the participant requires treatment with 
efgartigimod PH20 SC, they must follow SoA per Table 2 as of day X. 
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6. 
STUDY INTERVENTION(S) AND CONCOMITANT THERAPY 
All IMP is manufactured according to Good Manufacturing Practice regulations.  
6.1. 
Investigational Medicinal Product Administered 
In addition to the IMP, OCS will be provided by the sponsor as outlined in Table 5. TCS and 
rescue treatment will not be provided by the sponsor. 
Table 5: 
Study Intervention(s) Administered 
Intervention label 
Efgartigimod PH20 SC 
Placebo PH20 SC 
Oral OCS (prednisone 
or equivalent) 
Intervention name 
Efgartigimod for SC 
administration 
coformulated with 
rHuPH20 
Vehicle + rHuPH20 
Prednisone or equivalent 
tablets for oral 
administration 
Intervention 
description 
 
 
SC doses administered 
 
 on 
days 1 and 8 of the 
treatment 
Maintenance doses of 
1000 mg SC 
administered once 
weekly  
Refer to Section 6.3  
SC dose administered at 
 
as the efgartigimod SC 
dose on days 1 and 8 (if 
applicable) 
Refer to Section 6.3 
Initiated and adjusted 
according to the 
investigator’s clinical 
judgment 
Refer to Section 6.3 
Type  
Biologic 
Placebo 
NIMP/AxMP, 
concurrent therapy 
Dose formulation 
Solution for SC injection Solution for SC injection Prednisone (or 
equivalent) tablets for 
oral administration  
Unit dose 
strength(s) 
Efgartigimod 180 mg/mL 
rHuPH20 2000 U/mL  
rHuPH20 2000 U/mL 
Prednisone 2.5 mg, 
5 mg, 10 mg, and/or 
20 mg (or equivalent) 
Dosage level(s) 
Refer to Section 6.3 
Refer to Section 6.3 
Adjusted according to 
the investigator’s 
clinical judgment 
Route of 
administration 
SC injection 
SC injection 
Oral administration 
Use 
Experimental 
Placebo 
Concurrent therapy 
IMP and 
NIMP/AxMP 
IMP 
IMP 
NIMP/AxMP 
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Intervention label 
Efgartigimod PH20 SC 
Placebo PH20 SC 
Oral OCS (prednisone 
or equivalent) 
Sourcing 
Centrally by the sponsor 
Centrally by the sponsor 
Provided by the sponsor 
to the site 
Local sourcing is 
permitted only if no 
doses are available at the 
site and only after 
consultation with the 
sponsor (or designee) 
Packaging and 
labeling 
IMP will be provided in 
glass vials. Each vial 
will be labeled per 
country requirements. 
IMP will be provided in 
glass vials. Each vial 
will be labeled per 
country requirements. 
NIMP/AxMP will be 
provided as 1 of the 
following:  
In the commercial 
package and labeled as 
required per country 
requirements, or 
As a magistral 
preparation upon 
prescription by the 
investigator, or 
In the commercial 
package sourced locally 
Former name 
ARGX-113 
Not applicable 
Not applicable 
AxMP=auxiliary medicinal product; efgartigimod PH20 SC=efgartigimod for SC administration coformulated with 
rHuPH20; IMP=investigational medicinal product; NIMP=noninvestigational medicinal product; OCS=oral 
corticosteroids; rHuPH20=recombinant human hyaluronidase PH20; SC=subcutaneous 
6.2. 
Preparation, Handling, Storage, and Accountability 
• The IMP will be supplied to the investigational site by the sponsor’s designated IMP 
supply vendor.  
• The pharmacy manual provides detailed instructions on the preparation, handling, 
storage, accountability, and disposition of unused IMP. 
• The investigator or designee is responsible for the correct and safe storage of IMP. 
All IMP must be stored in a secure, environmentally controlled, and monitored 
(manual or automated) area following the labeled storage conditions, with access 
limited to the investigator and authorized site staff.  
• The investigator or designee must confirm that appropriate temperature conditions 
have been maintained for all IMP received during transit. Any discrepancies are 
reported and resolved before using the IMP. 
• Only participants enrolled in the study are permitted to receive IMP, and only 
authorized site staff or designee are allowed to supply IMP.  
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• IMP must be stored in secondary packaging, refrigerated (2 °C to 8 °C) and protected 
from direct sunlight. Do not shake IMP or expose it to freezing temperatures. 
• In exceptional cases, IMP, other BP therapies, and ancillaries may be shipped to 
participants by courier. 
6.3. 
Assignment to Study Intervention 
The following general principles apply to all participants. These principles apply to the specific 
situations described in Section 6.3.1 and Section 6.3.2 unless mentioned otherwise. 
• Efgartigimod PH20 SC can be initiated until week 45 to ensure a minimum of 
4 weeks of treatment. 
• Efgartigimod PH20 SC should be initiated without concurrent OCS if the participant's 
BP disease status permits it, according to the investigator’s clinical judgment. 
• Localized lesions should be treated with TCS before concurrent OCS treatment is 
considered, if possible. 
• If there is no improvement in the participant’s BP disease status and additional BP 
therapy is required while receiving efgartigimod PH20 SC, concurrent OCS treatment 
may be initiated according to the investigator’s clinical judgment. Recommendations 
for OCS therapy initiation and tapering are provided in Section 6.9.1. 
• As described in Section 6.9.2, rescue therapy will be tapered or discontinued in 
participants who received it in ARGX-113-2009. IMP will be permanently 
discontinued if the investigator considers it not to be in the participant’s best interest 
to taper or discontinue rescue therapy. 
6.3.1. 
Participants Who Roll Over After Protocol Amendment 2 Is Effective 
Situation 1: At roll over to this study 
These participants will receive efgartigimod PH20 SC while maintaining the ARGX-113-2009 
blinded treatment allocation of IMP (refer to Section 6.4). 
• Participants in the placebo arm in ARGX-113-2009 will receive 
 of 
efgartigimod PH20 SC 1000 mg (
 efgartigimod PH20 SC 
 on days 1 
and 8, followed by once-weekly injections of efgartigimod PH20 SC 1000 mg. 
• Participants in the efgartigimod PH20 SC arm in ARGX-113-2009 will receive 
 
 followed by once-weekly injections 
of efgartigimod PH20 SC 1000 mg. 
Situation 2: During this study's treatment period 
Participants will continue receiving efgartigimod PH20 SC and may receive TCS or concurrent 
OCS according to the investigator’s clinical judgment (refer to Section 6.9.1). 
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6.3.2. 
Participants Who Are Ongoing in This Study When Protocol Amendment 2 Is 
Effective 
Situation 3: Participants not receiving efgartigimod PH20 SC when protocol amendment 2 
is effective 
3A: Participants who are not receiving any BP therapy (ie, these participants achieved CR or 
PR while off concurrent BP therapy for ≥8 weeks before protocol amendment 2 was 
effective) 
• Once protocol amendment 2 is effective, efgartigimod PH20 SC may be initiated at 
the investigator’s discretion. If the participant relapses and requires additional BP 
therapy, efgartigimod PH20 SC must be initiated (
 on days 
1 and 8 followed by once-weekly injections of efgartigimod PH20 SC 1000 mg). 
3B: Participants who are being treated with rescue therapy that started in ARGX-113-2009 
• Rescue therapy will be tapered or discontinued (refer to Section 6.9.2) and 
efgartigimod PH20 SC will be initiated (
 on days 1 and 8 
followed by once-weekly injections of efgartigimod PH20 SC 1000 mg). 
Situation 4: Participants who are receiving efgartigimod PH20 SC when protocol 
amendment 2 is effective 
4A: Participants who are receiving efgartigimod PH20 SC with or without concurrent OCS 
• These participants will continue receiving efgartigimod PH20 SC and will continue 
their OCS tapering course. 
4B: Participants who are receiving efgartigimod PH20 SC and who are receiving rescue 
therapy that started in ARGX-113-2009 
• Rescue therapy will be tapered or discontinued (refer to Section 6.9.2) and 
efgartigimod PH20 SC treatment will be maintained. 
6.4. 
Blinding 
ARGX-113-2010 is open-label. The blinded allocation to efgartigimod PH20 SC or placebo from 
ARGX-113-2009 will be maintained until the database lock of ARGX-113-2009. Therefore, at 
rollover, participants receiving 
 on days 1 and 8 (Section 6.3) will receive 
 
 This will be handled via interactive response technology. 
The blinding of IgG and immunogenicity data for ARGX-113-2010 will also be maintained until 
the database lock of ARGX-113-2009. 
BP autoantibody data and albumin and total protein data collected from baseline through week 4 
will remain blinded. 
6.5. 
Study Compliance 
IMP must be administered at the site for a minimum of 3 consecutive visits before 
(self-)administration of IMP by the participant or caregiver is allowed at home. Participants or 
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caregivers must also have completed (self-)administration training at the site during 
ARGX-113-2009 and be considered capable by the site of performing the (self-)administration. 
At mandatory on-site visits, 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 on-site visit and documented in the source documents and relevant forms. 
Deviation(s) from the prescribed dosage regimen will be recorded. 
6.6. 
Dose Modification 
Dose modifications are not permitted. 
6.7. 
Continued Access to IMP After the End of the Study 
At the end of the study, argenx cannot guarantee continued access for participants but will 
comply with all local laws and regulations. 
6.8. 
Treatment of Overdose 
Any variation of >10% of the intended weekly dose of efgartigimod PH20 SC will be considered 
an overdose. 
The sponsor does not recommend specific treatment for an overdose. 
If an overdose occurs, the investigator/treating physician will: 
• Evaluate the participant to determine if IMP will be interrupted. 
• Closely monitor the participant for any AE/SAE and laboratory abnormalities (as 
medically appropriate and at least until the next scheduled follow-up). 
• Immediately report the overdose, the quantity of the excess dose, and the overdose 
duration to the sponsor. 
6.9. 
Prior and Concomitant Therapy 
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 baseline or during the study must 
be recorded and include the following information: 
• Reason for use 
• Dates of administration, including start and end dates 
• Dosage information (ie, dose and frequency) 
• Brand name (for vaccines only) 
The following medications or treatments are not permitted as of when the ICF has been signed 
through the completion of the EoTP visit or EDV, as applicable:  
• SC immunoglobulin 
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• IV immunoglobulin unless initiated as rescue therapy in ARGX-113-2009 (refer to 
Section 6.9.2) 
• Plasma exchange 
• Immunoadsorption  
• Monoclonal antibodies: 
− Rituximab 
− Other anti-CD20 biologics 
− Other monoclonal antibodies 
• Sulfasalazine 
• Any systemic treatment for BP (eg, IV or intramuscular corticosteroids, systemic 
immunosuppressants) except OCS  
• Complementary therapies, including traditional Chinese medicines, herbs, or 
procedures (eg, acupuncture) that may interfere with the study’s efficacy assessments 
and/or potentially risk the safety of the participant 
• Live or live-attenuated vaccines 
• Any other systemic biologic agent or experimental/study IMP 
6.9.1. 
Oral Prednisone Tapering and Escalation 
Participants may receive concurrent therapy with OCS, ie, prednisone or an alternative OCS. If 
on OCS, the dosage will be adjusted according to each participant’s BP disease status throughout 
the study. The goal is to taper systemic corticosteroid exposure rapidly.  
Note: For the following list, “oral prednisone” refers to prednisone or an alternative OCS of 
equivalent dose strength. 
• Participants who were receiving concurrent OCS in ARGX-113-2009 will continue their 
OCS tapering course, as outlined in this section. 
• New treatment courses with oral prednisone may be initiated if there is a lack of clinical 
improvement in the participant’s BP disease status and additional BP therapy is required. 
The starting dose of oral prednisone should be the lowest advisable dose and must not 
exceed 0.5 mg/kg/day. The choice of the starting dose within the specified range is at the 
investigator’s discretion. 
• Escalated doses of oral prednisone may be considered if the participant does not achieve 
CDA within 1 to 3 weeks of prednisone at or below 0.5 mg/kg/day. Participants who do 
not achieve CDA despite receiving efgartigimod PH20 SC with escalated dosages of 
OCS (0.75 mg/kg/day or higher) will be considered treatment failures (refer to the 
Definitions of Terms for a full description) and IMP will be permanently discontinued. 
• When CDA is achieved, the oral prednisone dose regimen is adjusted based on the 
investigator's clinical judgment. Recommendations for tapering are as follows: 
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− After CDA has been sustained for ≥2 weeks, the tapering schedule begins with the 
next lower oral prednisone dosage, as listed in Table 6. Each new dosage will be 
maintained for 2 weeks or less, based on the investigator’s clinical judgment. 
Note: For participants with body weights <45 kg and ≥110 kg, the investigator should 
propose an OCS dose per the recommended doses in Table 6 and inform the medical 
monitor to ensure consistency in the study. 
• The OCS dosage may be adjusted according to the investigator’s clinical judgment if 
disease activity occurs during the OCS tapering. 
Refer to Table 9 for concurrent oral methylprednisolone equivalent doses. 
Notes:  
• Prophylactic and supportive care to diminish the expected side effects of OCS (ie, 
antiosteoporotic treatments, calcium supplements and vitamin D) are allowed in the 
study. 
 
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6.9.2. 
Rescue Therapy Tapering and Discontinuation 
Once protocol amendment 2 is effective, newly enrolled and ongoing participants who receive 
rescue therapy started in ARGX-113-2009 will initiate or continue efgartigimod PH20 SC and 
rescue therapy will be tapered or discontinued. IMP will be permanently discontinued if the 
investigator considers it not to be in the participant’s best interest to taper or discontinue rescue 
therapy or initiate efgartigimod PH20 SC (refer to Section 7.1.1). 
Guidelines for rescue therapy types are as follows: 
• Whole body TCS application should be stopped immediately. 
• OCS used as rescue therapy should be tapered according to the instructions in 
Section 6.9.1. 
• Immunosuppressants should be stopped immediately. 
• Tetracyclines should be stopped immediately. 
• IVIg should be stopped immediately and a 2-week washout period must be 
implemented before initiating efgartigimod PH20 SC. 
 
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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). 
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.  
Unless consent from the study has been withdrawn, the participant will attend an EDV and safety 
follow-up visits on-site, as specified in the SoA (Section 1.3). Study sites should perform the 
EDV within 7 days after the participant’s final IMP administration and safety follow-up visits 4 
and 8 weeks after the participant’s final IMP administration.  
The following circumstances will result in the permanent discontinuation of IMP: 
• Participant becomes pregnant or intends to become pregnant (refer to Section 8.3.5). 
• 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. 
• Treatment failure (Definitions of Terms). 
• Investigator decides to not initiate efgartigimod PH20 SC treatment at rollover or 
after relapse. 
• Investigator considers tapering or discontinuing rescue therapy started in 
ARGX-113-2009 not to be in the participant’s best interest. 
• 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 IMP. 
• Participant develops any of the following, based on the sponsor’s determination of 
relatedness:  
− Any treatment-emergent AE of NCI CTCAE grade 4 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 
• Participant develops any malignancy, either new or recurrent, other than basal cell 
carcinoma of the skin, regardless of relatedness to IMP. 
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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 any of the following: 
• Any SAE considered related to IMP by the sponsor 
• Clinically significant active infection considered related to IMP by the sponsor 
• Any of the following liver chemistry laboratory results: 
− ALT or AST values >8 × 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 >1.5 
− ALT or AST values >3 × ULN with the appearance of any of the following signs 
and symptoms of liver toxicity: 
▪ Fatigue 
▪ Nausea 
▪ Vomiting 
▪ Pain or tenderness in the upper-right quadrant of the abdomen 
▪ Fever 
▪ Rash 
▪ Eosinophilia (eosinophil count >5 × 108/L) 
Note: 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 study intervention (eg, viral hepatitis, preexisting or acute liver disease, or toxicity 
related to concomitant medications other than study intervention). If the event is 
considered by the investigator to be related to the IMP, treatment will be permanently 
discontinued (Section 7.1.1). 
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. 
If possible, an EDV and safety follow-up visit(s) should be conducted when the participant is 
withdrawn from the study. Study sites should make every effort to schedule the EDV and safety 
follow-up visit(s) as follows: 
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• Participants on efgartigimod PH20 SC treatment should attend the EDV 7 days after 
the participant’s final IMP administration; the safety follow-up visits should occur 
4 and 8 weeks after the participant’s final IMP administration. 
• Participants in the observation period should attend the EDV within 7 days after the 
last contact with the site and a safety follow-up visit 8 weeks after the previous 
contact. 
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. 
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 is unable to be contacted by the study site. 
The following actions must be completed if a participant fails to complete 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 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 (when 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 will be documented in the 
participant’s medical record. 
− Participants who continue to be unreachable will be considered to have withdrawn 
from the study.  
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8. 
STUDY ASSESSMENTS AND PROCEDURES 
• Study procedures and their timing are summarized in the SoA (Section 1.3). Protocol 
waivers or exemptions are not allowed. 
• Adherence to the study design requirements, including those specified in the SoA, is 
required for study conduct. 
• Visits that must be attended at the site are baseline; weeks 1, 2, 4 and 8; and thereafter 
every 4 weeks while on efgartigimod PH20 SC treatment or every 8 weeks while off 
efgartigimod PH20 SC treatment (observation period), week 48 (EoTP), EoTP + 4 
weeks for participants on efgartigimod PH20 SC treatment at week 48, and EoTP + 8 
weeks for all participants. 
• Weekly efgartigimod PH20 SC injections that are scheduled between mandatory 
on-site visits may be administered by a home nurse (either a nurse from the study site 
or a nurse from a commercial nursing vendor who is delegated by the investigator), 
the participant, or a caregiver (Section 6.5). 
• Operational considerations related to the COVID-19 pandemic are provided in 
Section 10.5. 
8.1. 
Administrative and General/Baseline Procedures 
The baseline visit will occur on the same day as the EoTP visit of ARGX-113-2009. All baseline 
assessments will be performed before administration of efgartigimod PH20 SC. Assessments do 
not need to be repeated if they are performed as part of ARGX-113-2009. 
8.1.1. 
Use and Storage of Biological Samples 
After the protocol-defined laboratory analyses have been completed, any samples remaining can 
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. These samples may be used for future 
additional medical, academic, or scientific research to address any scientific questions related to 
efgartigimod, FcRn biology, or BP, unless prohibited by local regulations or the participant. 
In addition, blood samples 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 measurements are performed. 
8.2. 
Efficacy Assessments 
Time points for all efficacy assessments are provided in the SoA (Section 1.3). 
Investigators are trained in completing efficacy assessments. Instructions on completing PRO 
questionnaires are provided in the applicable study manuals. 
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8.2.1. 
Efficacy Measures 
8.2.1.1. 
Assessment of BP Disease Status and OCS Dose Monitoring 
The BP disease status will be assessed by the investigator at on-site visits according to the 
definitions/criteria presented in the Definitions of Terms. During these visits, the investigator 
will examine the participant for new lesions (transient or nontransient), record the daily 
concurrent BP therapy (if applicable) administered to the participant since the last visit, including 
the dose, adjust the daily OCS dose (taper, stop, reinitiate, or increase; if applicable) based on the 
participant’s BP disease status, and record treatment failure.  
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, an 
assessment tool that was developed in 2021 by medical experts in the field of AIBDs. It is 
currently being used (along with the BPDAI) in other BP clinical studies. The IGA-BP 
categorizes the severity of BP on a numerical scale of 0 (clear) to 4 (severe). 
8.2.1.3. 
Bullous Pemphigoid Disease Area Index 
BP disease activity will be assessed by the investigator using the BPDAI.3 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.1,3  
8.2.1.4. 
Itch Numerical Rating Scale 
Participants will indicate pruritic symptoms of BP on the 11-point itch NRS (0 [no itch], 10 
[worst itch imaginable]). An average and the worst score for itch suffered within the past 
24 hours will be recorded.7,8 
8.2.2. 
Quality of Life Assessments 
Time points for all PRO assessments are provided in the SoA (Section 1.3). If the time point of 
the assessment does not coincide with a planned on-site visit, the assessment should be 
performed at the next on-site visit. Subsequent PRO assessments should then be calculated based 
on that last PRO assessment.  
8.2.2.1. 
EQ-5D-5L 
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.  
The descriptive system comprises 5 dimensions (mobility, self-care, usual activities, 
pain/discomfort, anxiety/depression). Each dimension has 5 levels: no problems, slight problems, 
moderate problems, severe problems, and extreme problems.  
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8.2.2.2. 
Dermatology Life Quality Index 
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.”9 
8.2.2.3. 
Autoimmune Bullous Disease Quality of Life Index  
The ABQoL was developed and validated for determining the impact of AIBDs and their 
therapies on the daily lives of patients. The series of 17 questions concerns the participant’s 
perceptions of how AIBD affects their daily lives, and includes comfort, hygiene, 
eating/drinking, appearance, social interactions, sexual activity, and employment.10  
8.3. 
Safety Assessments 
Time points for all safety assessments are provided in the SoA (Section 1.3). Safety measures 
will be assessed before IMP administration unless otherwise stated. 
8.3.1. 
Vital Signs 
• Body temperature, pulse rate, respiratory rate, and blood pressure will be recorded 
before blood collection for laboratory tests. 
• Blood pressure and pulse will be assessed with the participant rested. 
8.3.2. 
Physical Examinations 
• A complete physical examination will include, at a minimum, assessments of the 
musculoskeletal, gastrointestinal, pulmonary, cardiovascular, respiratory, and 
neurological systems and general appearance, skin, and lymph nodes. Height and 
weight will also be measured without shoes, attired in light clothing, and recorded 
using validated instruments. 
• Brief physical examination will include assessments of gastrointestinal, pulmonary, 
cardiovascular, and respiratory systems and general appearance. 
8.3.3. 
Electrocardiograms 
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. 
At all planned on-site visits per the SoA in Section 1.3, new clinically significant abnormal or 
worsened preexisting ECG abnormalities will be reported as AEs. 
8.3.4. 
Protocol-Required Laboratory Tests 
• Blood and urine samples will be analyzed at a central laboratory for serum chemistry 
and hematology, coagulation, urinalysis, serology (eg, viral marker testing), and 
specialty laboratory parameters (eg, PD, immunogenicity, vaccination substudy). In 
China, laboratory parameters will be analyzed using central and/or local laboratory 
facilities. 
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• Refer to Appendix 2 (Table 7) for the list of protocol-required laboratory tests to be 
performed and the SoA (Section 1.3) for the timing. 
• The investigator must review the laboratory results, document this review, and record 
any clinically significant changes occurring during the study as an AE. The laboratory 
results must be retained with source documents.  
• 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. 
8.3.4.1. 
Substudy—Vaccination Response 
The vaccination substudy from ARGX-113-2009 will continue in this OLE study in participants 
who provided additional consent for collecting blood samples postvaccination and for whom this 
substudy has not been completed yet. Postvaccination samples may be collected for 
additional/optional/future vaccination research at the visits identified in the SoA (Section 1.3). 
Such research may include, but is not limited to, the following:  
• Humoral (serum) responses to vaccinations received in ARGX-113-2009 
• Cellular (peripheral blood mononuclear cells) responses to vaccinations received in 
ARGX-113-2009 
Data obtained from this substudy will not be included in the clinical database; the results may be 
described in a separate report. 
8.3.5. 
Pregnancy Testing 
• WOCBP will be tested for pregnancy. Urine tests for pregnancy will occur at the time 
points specified in the SoA (Section 1.3). 
• Home testing kits will be provided to the participants for urine pregnancy tests 
scheduled between mandatory on-site visits.  
• Pregnancy testing in WOCBP will be conducted at the end of relevant systemic 
exposure, as specified in the SoA (Section 1.3). 
• 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 to12 months after the baby’s birth. 
8.3.6. 
Glucocorticoid Toxicity Index 
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 
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monitoring of the long-term tolerability of glucocorticoids during their prolonged use during 
clinical practice.11  
The GTI should be assessed per the SoA in Section 1.3. If the time point of the assessment does 
not coincide with a planned on-site visit, the assessment should be performed at the next on-site 
visit. Subsequent GTI assessments should then be calculated based on that last GTI assessment. 
The GTI v2.0 consists of the following 2 instruments: 
• The C-GTI serves as a primary instrument intended to capture toxicities that are likely 
related to glucocorticoid exposure. The C-GTI has 9 functional domains: body mass 
index, 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. It is typically 
excluded from studies <1 year in duration, because bone densitometry is not sufficiently 
reliable in measuring changes over shorter durations.11  
Two analytical scores are generated from the weighted C-GTI items: the GTI-CWS and 
the GTI-AIS. The GTI-CWS is designed to assess cumulative glucocorticoid toxicity, and 
the GTI-AIS can be used to assess whether a new therapy is effective in reducing 
glucocorticoid toxicity over time. Together, the GTI-CWS and GTI-AIS provide 
complementary information about the ability of an investigational agent to reduce overall 
glucocorticoid toxicity. 
• The GTI-SL captures well-known glucocorticoid-related side effects. This nonweighted 
instrument provides additional information for the domains most affected by 
glucocorticoid use during the participant’s treatment. It comprises 11 domains (9 of 
which are shared with the C-GTI) and 23 items.  
Note: For the reason mentioned previously, the GTI-SL item covering bone mineral 
density decrease (part of the bone health domain) will not be used in this study. 
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.  
The following measures are recommended during the study: 
• Initiate or renew administration of non-live, inactivated, polysaccharide, or 
recombinant vaccines (eg, tetanus, hepatitis A, hepatitis B, shingles).  
• Vaccinate participants who are especially prone to or have a history of respiratory 
infections against Pneumococcus or Streptococcus pneumoniae. 
• Vaccinate participants with seasonal vaccines (eg, influenza virus), especially those 
entering the study in the winter months. 
• Screen for possible infections (eg, respiratory, skin, mouth, eyes, nose and throat, 
genitals) and, if appropriate, initiate antibiotic treatment.  
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• 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 
investigator’s discretion and if it is administered at least 48 hours predose or 48 hours postdose 
of efgartigimod PH20 SC. 
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. 
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. 
Suicidal Ideation and Behavior Monitoring 
Not applicable. 
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 8.4.6. 
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). 
8.4.1. 
Time Period and Frequency for Collecting AE and SAE Information 
All AEs will be collected from the signing of the ICF until the EoTP + 8 weeks visit, as specified 
in the SoA (Section 1.3). 
All SAEs and AESIs will be recorded and reported to the sponsor or designee immediately, and 
under no circumstance will this exceed 24 hours, as indicated in Appendix 3 (Section 10.3). 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 the conclusion 
of the study participation. However, if the investigator learns of any SAE, including death, at any 
time after a participant has been discharged from the study, and they consider the event to be 
reasonably related to IMP or study participation, the investigator must promptly notify the 
sponsor. 
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8.4.2. 
Method of Detecting AEs and SAEs 
Care will be taken not to introduce bias when detecting AEs and SAEs. Open-ended and 
nonleading verbal questioning of the participant is preferred to inquire about AE occurrences. 
8.4.3. 
Follow-up of AEs and SAEs 
After the initial AE/SAE report, the investigator must proactively follow each participant at 
subsequent visits/contacts. All SAEs and AESIs defined in Section 8.4.6 will be followed until 
resolution, stabilization, the event is otherwise explained, or the participant is lost to follow-up 
(defined in Section 7.3). Further information on follow-up procedures is provided in 
Section 10.3. 
8.4.4. 
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 
file it with the IB and notify the IRB/IEC, if appropriate, according to local 
requirements. 
• The sponsor or designee will be responsible for reporting SUSARs to the relevant 
regulatory authorities and IEC/IRB, per applicable regulatory requirements. The 
sponsor or designee will also be responsible for forwarding SUSAR reports to all 
study investigators, who will be required to report these SUSARs to their respective 
IECs/IRBs per local regulatory requirements.  
8.4.5. 
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 of a participant, 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, 
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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. 
• Any female participant who becomes pregnant during the study will discontinue IMP. 
8.4.6. 
AESIs 
An AESI is an event of scientific and medical concern specific to the sponsor’s product or 
program. An AESI can be serious or nonserious, related or not related to the IMP or study 
procedures. These events will be reported according to the same time frame as that for SAEs 
specified in Section 8.4.1 and Section 10.3.4.  
Efgartigimod treatment leads to reduced IgG levels. As low IgG levels can be associated with 
increased infection risks, events in the MedDRA 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 
• Any confirmatory procedure, culture, or urgent medical intervention, if applicable 
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. 
AEs of Clinical Interest 
8.4.7.1. 
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. As with any SC or IV injection, injection- or infusion-related reactions 
can occur during or after administration. Overall, the frequency of injection-related reactions in 
clinical studies has been low.  
Refer to the current IB for more information on infusion/injection-related reactions. 
8.4.7.2. 
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.  
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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 
Pharmacokinetics are not evaluated in this study. 
8.6. 
Pharmacodynamics 
Baseline and postbaseline PD blood samples will be collected predose on IMP administration 
visits (preferably within 2 hours before IMP administration) as described in the SoA 
(Section 1.3).  
Anti-BP180 antibodies, anti-BP230 antibodies, 
 will be determined using 
validated assays. 
PD blood samples may be used for methodology validation and/or for future research purposes 
(Section 8.1.1). Such use of these samples is only permitted after obtaining consent from the 
participant. 
8.7. 
Genetics 
Genetics are not evaluated in this study. 
8.8. 
Biomarkers 
Biomarkers are not evaluated in this study. 
8.9. 
Immunogenicity Assessments 
Blood samples will be collected at the time points indicated in the SoA (Section 1.3), predose on 
IMP administration visits (preferably within 2 hours before IMP administration), to evaluate 
serum levels of ADA against efgartigimod and plasma levels of antibodies against rHuPH20. 
Samples to determine plasma levels of antibodies against rHuPH20 will be collected and stored 
and will be analyzed in case of safety concerns. 
Samples will be analyzed by the designated laboratory in a tiered approach using validated 
immunogenicity assays.12 Initially, samples will be screened for a positive assay response 
(tier 1). Screened positive samples will then be tested in a confirmation assay (tier 2). Finally, a 
titration of the ADA response will be performed on positive tier 2 samples to characterize the 
magnitude of the antibody response, and a neutralizing antibody assay will be performed to 
assess the antibodies for neutralizing activity (tier 3). 
Immunogenicity blood samples may be used for methodology validation and/or for future 
research purposes (Section 8.1.1). Such use of these samples is only permitted after obtaining 
consent from the participant. 
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8.10. 
Health Economics and Medical Resource Utilization  
Health economics and/or medical resource utilizations are not evaluated in this study. 
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9. 
STATISTICAL CONSIDERATIONS 
The SAP will be finalized before database lock and will include a more technical and detailed 
description of the statistical analyses described in this section. This section is a summary of the 
planned statistical analyses of the most important endpoints including primary and secondary 
endpoints. 
9.1. 
Statistical Hypotheses 
No formal hypothesis testing will be conducted in this open-label study. 
9.2. 
Analysis Sets 
The following analysis sets are defined: 
Analysis set 
Description 
Rollover set 
All participants who rolled over from ARGX-113-2009 
Safety set 
All participants exposed to IMP 
Per protocol set 
No per protocol set is defined.  
Note: Important protocol deviations will be summarized in a 
table and presented in a listing.  
Additional analysis sets and/or populations may be further defined in the SAP. 
9.3. 
Statistical Analyses 
9.3.1. 
General Considerations 
• Descriptive statistical methods will be used to analyze all primary and secondary 
endpoints. For continuous variables, summaries will include the number of 
observations (n), mean, SE, 95% CI, median, minimum, and maximum. For 
categorical variables, summaries will include the number of participants, frequencies, 
and percentages. No inferential analyses are foreseen. 
• AEs will be classified using the latest version of the MedDRA classification system.  
• AEs, AESIs, and SAEs will be listed corresponding to MedDRA SOC and PT. 
• All AEs will be summarized by relatedness to efgartigimod PH20 SC. 
• Any AEs leading to death or discontinuation of efgartigimod PH20 SC will be 
summarized. 
• Multiple occurrences of a single PT in a participant will be counted only once at the 
maximum severity/grade.  
• Laboratory parameters, physical examinations, vital sign measurements, PD, and 
immunogenicity results will be analyzed descriptively. 
The baseline value for ARGX-113-2010 will be the value at the EoTP visit of ARGX-113-2009. 
All study visits will be recalculated based on actual dates and will be referred to as “analysis 
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visits” that will be used in the statistical analyses. The rules for calculating the analysis visits and 
the rules for imputing partial dates or missing dates will be provided in the SAP. 
Analyses will not only refer to the baseline of ARGX-113-2010; the baseline value of 
ARGX-113-2009 may be used for specific analysis as will be outlined in the SAP for this OLE 
study. 
9.4. 
Interim Analysis 
Administrative interim analyses may be performed in support of potential regulatory authority 
interactions and will be described in detail in the SAP. 
9.5. 
Sample Size Determination 
The maximum number of participants in this study is the number of participants who complete 
the week 36/EoTP visit in ARGX-113-2009 and meet the eligibility criteria to roll over to this 
study. 
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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 according to the protocol and the following: 
− Consensus ethical principles derived from international guidelines including the 
Declaration of Helsinki and Council for International Organizations of Medical 
Sciences international ethical guidelines 
− Applicable ICH GCP guidelines 
− Applicable laws and regulations 
• The protocol, protocol amendments, ICF, IB, and other relevant documents (eg, 
advertisements) must be submitted to and approved by the IRB/IEC before the study 
is initiated. 
• Any amendments to the protocol will require IRB/IEC approval before implementing 
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 is responsible for the following: 
− Providing written summaries of the status of the study to the IRB/IEC annually or 
more frequently according to 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 study conduct at the site and adhering to requirements of 
21 CFR, ICH guidelines, the IRB/IEC, local laws and regulations for clinical 
studies, and all other applicable local regulations 
10.1.2. 
Financial Disclosure 
Investigators and subinvestigators will provide the sponsor with sufficient and accurate financial 
information as requested to allow the sponsor to submit a complete and accurate financial 
certification or disclosure statements to the appropriate regulatory authorities. Investigators are 
responsible for providing information on financial interests during the study and for 1 year after 
study completion. 
The following information will be collected: any significant payments from the sponsor such as a 
grant to fund ongoing research, compensation in the form of equipment, retainer for ongoing 
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consultation or honoraria, proprietary interest in IMP, and significant equity interest in the 
sponsor as defined in 21 CFR 54 2(b) (1998). 
10.1.3. 
Informed Consent Process 
• The investigator or representative will explain the nature of the study, including risks 
and benefits to the potential participant and answer all questions before the participant 
completes the informed consent process by signing the ICF. 
• Potential participants must be informed that their participation is voluntary. An ICF 
must be signed that meets the requirements of the IRB/IEC or study center, ICH 
guidelines, local laws and regulations, and, where applicable, privacy and data 
protection requirements. 
• 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. 
10.1.4. 
Recruitment Strategy 
Not applicable as participants will roll over from ARGX-113-2009. 
10.1.5. 
Data Protection 
• The sponsor will assign participants a unique identifier. Any participant records or 
datasets transferred to the sponsor will contain the identifier only; participant names 
or any information that would make the participant identifiable will not be 
transferred. 
• The participant must be informed that the sponsor, sponsor representatives, competent 
authorities, etc can review source data containing identifiers and will use their 
personal study-related data per 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 ICF. 
• The contract between sponsor and study sites specifies responsibilities of the parties 
related to data protection, including handling of data security breaches and respective 
communication and cooperation of the parties. 
• Information technology systems used to collect, process, and store study-related data 
are secured by technical and organizational security measures designed to protect 
such data against accidental or unlawful loss, alteration, or unauthorized disclosure or 
access. 
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10.1.6. 
Committees Structure 
Not applicable. 
10.1.7. 
Dissemination of Clinical Study Data 
The sponsor will register and disclose the clinical study results as required by law. 
10.1.8. 
Data Quality Assurance 
• The sponsor or designee is responsible for the data management of this study, 
including quality checking of the data. 
• All participant data relating to the study will be recorded on eCRFs unless transmitted 
to the sponsor (or its designee) electronically (eg, laboratory data) or via paper SAE 
forms. The investigator is responsible for verifying that data entries are complete, 
accurate, and verifiable by electronically signing the eCRF. 
• Guidance on completing eCRFs is provided on the eCRF completion document. 
• The investigator must permit study-related monitoring, audits, IRB/IEC review, and 
regulatory agency inspections and direct access to the site and study documentation, 
including source data documents. 
• Study processes, study sites (including but not limited to site visits, central 
laboratories, vendors), the study database, and study documentation are subject to 
quality assurance audit during the study by the sponsor or sponsor’s designee on 
behalf of the sponsor. In addition, inspections could be conducted by foreign or 
domestic regulatory bodies at their discretion. Such audits/inspections can occur 
during or after study completion. 
• QTLs will be predefined in the QTL Plan to identify systematic issues that can impact 
participant safety and/or reliability of study results. These predefined parameters will 
be monitored during the study, and important deviations from the QTLs and remedial 
actions taken will be summarized in the clinical study report. 
• Records and documents, including signed ICFs, on the conduct of this study must be 
retained by the investigator for at least 25 years after study completion unless local 
regulations or institutional policies require a more extended retention period. Without 
the sponsor’s written approval, no records will be destroyed during the retention 
period. No records are allowed to be transferred to another location or party without 
the sponsor’s written approval. 
• Monitoring details describing strategy and activities are outlined in a monitoring plan.  
− Study monitors will perform ongoing source data verification to confirm that data 
entered on 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 following the currently approved 
protocol and any other study agreements, ICH GCP, and all applicable regulatory 
requirements. 
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10.1.9. 
Source Documents 
• Source documents provide evidence of 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 else 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 definition of what constitutes source data and its origin can be found in the 
monitoring plan. 
• The investigator must maintain accurate documentation (source data) that supports 
the information entered on the eCRF. 
• The sponsor or designee will perform monitoring to confirm that data entered on 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. 
10.1.10. 
Study and Site Start and Closure 
First Act of Recruitment 
The study start date is the date on which the first participant completes ARGX-113-2009 and 
rolls over to ARGX-113-2010. 
Study/Site Termination 
The sponsor or designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the sponsor. Study sites will be closed upon study 
completion. A study site is considered closed when all required documents and study supplies 
have been collected and a study-site closure visit has been performed. 
The investigator could 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 early closure of a study site by the sponsor or investigator could include but are not 
limited to the following: 
• For study termination: 
− Discontinuation of further compound development 
• For site termination: 
− Failure of the investigator to comply with the protocol, requirements of the 
IRB/IEC or local health authorities, sponsor’s procedures, or GCP guidelines 
− Inadequate or lack of recruitment (evaluated after a reasonable amount of time) of 
participants by the investigator 
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− Total number of participants enrolled earlier than expected 
If the study is prematurely terminated or suspended, the sponsor will promptly inform the 
investigators, the IECs/IRBs, the regulatory authorities, and any contract research organization(s) 
used in the study of the reason for termination or suspension, as specified by the applicable 
regulatory requirements. The investigator will promptly inform the participant and ensure 
appropriate therapy and/or follow-up for the participant, as necessary. 
10.1.11. 
Publication Policy 
• The results of this study can be published or presented at scientific meetings. If so, 
the investigator agrees to submit all manuscripts or abstracts to the sponsor before 
submission. This allows the sponsor to protect proprietary information and provide 
comments. 
• The sponsor will comply with the requirements for publication of study results. In 
accordance with standard editorial and ethical practice, the sponsor will generally 
support publication of multicenter studies only in their entirety and not as individual 
site data. In this case, a coordinating investigator will be designated by mutual 
agreement. 
• Authorship will be determined by mutual agreement and consistent with International 
Committee of Medical Journal Editors authorship requirements. 
 
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10.2. 
Appendix 2: Clinical Laboratory Tests 
• The tests listed in Table 7 will be performed as described in the laboratory manual. 
• Protocol-specific requirements for the inclusion and exclusion of participants are detailed 
in Section 5.1 and Section 5.2, respectively. 
• Additional tests can be performed during the study as determined necessary by the 
investigator or required by local regulations. 
• Investigators must document their review of each laboratory test result. 
Table 7: 
Protocol-Required Laboratory Tests  
Laboratory test 
Parameters 
Hematology 
RBC count 
platelet count 
hemoglobin 
hematocrit 
RBC indices: 
MCV 
MCH 
 
WBC count with 
differential: 
neutrophils 
lymphocytes  
monocytes  
basophils 
eosinophils 
Serum chemistry 
ALT 
AST 
ALP 
albumina 
bilirubin (total and direct) 
BUN 
sodium 
calcium 
creatinine 
CRP 
GGT 
glucose 
HbA1c 
potassium 
total proteina  
 
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 
Urine test (as needed for WOCBP, defined in Section 10.4.1)  
Specialty laboratory tests 
INR 
Unscheduled SARS-CoV-2 
testing 
It is recommended that participants who develop COVID-19 symptoms be 
tested (Section 10.5)  
Pharmacodynamic markers 
Anti-BP180 antibodies, anti-BP230 antibodies, 
  
Immunogenicity 
• Serum levels of ADA against efgartigimod  
• Plasma levels of antibodies against rHuPH20 to be tested in case of safety 
concerns 
ADA=antidrug antibodies; ALT=alanine aminotransferase; AST=aspartate aminotransferase; ALP=alkaline 
phosphatase; BUN=blood urea nitrogen; CRP=C-reactive protein; GGT=gamma-glutamyl transferase; 
HbA1c=glycosylated hemoglobin; HDL=high-density lipoprotein;
 INR=international 
normalized ratio; LDL=low-density lipoprotein; MCH=mean corpuscular hemoglobin; MCV=mean corpuscular 
volume; RBC=red blood cell; rHuPH20=recombinant human hyaluronidase PH20; WBC=white blood cell; 
WOCBP=women of childbearing potential  
a Albumin and total protein collected from baseline through week 4 will not be reported to the site. A system will be 
implemented that will alert the investigator of out-of-range values, to allow for appropriate safety follow-up. 
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10.4. 
Appendix 4: Contraceptive and Barrier Guidance 
10.4.1. 
Women of Childbearing Potential Definition 
A female is considered a WOCBP unless she is either:  
a. Postmenopausal: 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 and therefore an FSH test to confirm 
a postmenopausal state is not considered valid. In this case, the postmenopausal state 
will need to be assessed by the investigator. 
b. Surgically sterilized: Documented permanent sterilization procedure (eg, 
hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) 
10.4.2. 
Contraception Guidance 
10.4.2.1. Female Contraception for WOCBP 
WOCBP must use 1 of the following contraception methods from signing the ICF until the last 
dose of IMP. 
The following CTFG13 methods are permitted for efgartigimod: 
• Male or female condom with or without spermicide 
• Cap, diaphragm, or sponge with spermicide 
• Combined (estrogen-containing and progestogen-containing) hormonal contraception 
associated with ovulation inhibition: 
− Oral 
− Intravaginal 
− Transdermal 
• Progestogen-only hormonal contraception associated with inhibition of ovulation: 
− Oral 
− Injectable 
− Implantable 
• Progesterone-only hormonal contraception, where inhibition of ovulation is not the 
primary mode of action 
• Intrauterine device 
• Intrauterine hormone-releasing system 
• Bilateral tubal occlusion 
• Vasectomized partner 
• Sexual abstinence 
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10.4.2.2. Male Contraception 
No male contraception is required. 
 
 
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10.5. 
Appendix 5: Operational Considerations for COVID-19 Risk 
Mitigation 
During the study, the sites will implement all recommendations issued by the local government 
regarding 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 result 
in new restrictions at the site or new risks for participants or site staff from attending visits at the 
site. 
Testing for COVID-19 is not required during the study unless required by local authorities. 
However, it is recommended that participants who develop COVID-19 symptoms be tested, with 
results reported for the study. 
Critical Parameters to Be Collected During the Study 
All assessments will be performed as indicated in the SoA (Section 1.3), if possible. If 
assessments cannot be performed because of the COVID-19 pandemic, the following 
information must be collected from the first visit through the end of the study:  
• All AE and concomitant medication reporting 
• Injection-related reactions 
• IMP administration 
• Protocol-required laboratory assessments 
Study visits, other than the baseline visit, designated as mandatory on-site visits (Section 1.3) 
may be performed at the participant’s home (or an alternative convenient location). Such home 
visits will include sample collections as described in Table 8. 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-administration or caregiver administration, provided that the participant or caregiver has 
completed the training and has been considered competent.  
Table 8: 
Scheme for Study Visits Performed at Home During COVID-19 Pandemic 
Critical assessment 
Performed by 
Method of assessment 
Updates/addenda to original informed consent 
(other than those conducted at baseline) 
Investigator 
Audio or video interview 
Disease assessment (CDA, PR, CR, relapse, 
treatment failure) 
Investigator 
Audio or video interview 
AEs 
Investigator 
Audio or video interview 
Injection-related reactions  
Investigator 
Audio or video interview 
Concomitant medications 
Investigator 
Audio or video interview 
Concurrent BP adjustment evaluation 
Investigator 
Audio or video interview 
Vital sign measurements 
Home nursea 
In person at participant’s homeb 
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Critical assessment 
Performed by 
Method of assessment 
Blood collection (for safety assessments only) 
Home nursea 
In person at participant’s homeb 
Urine collection (for safety assessments only) 
Home nursea 
In person at participant’s homeb 
IMP administration 
Home nursea or 
self-administered 
In person at participant’s homeb 
AE=adverse event; BP=bullous pemphigoid; CDA=control of disease activity; CR=complete remission; 
IMP=investigational medicinal product; PR=partial remission 
a Either a nurse from the study site or a nurse from a commercial nursing vendor who is delegated by the 
investigator. 
b Study visit may also be performed at an alternative convenient location.  
 
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10.6. 
Appendix 6: Protocol Amendment History 
Amendment 1 (02 Jun 2023) 
This amendment is considered 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 the Amendment 
The primary rationale for this amendment is to incorporate health authority feedback. 
In addition, potential risks and mitigation strategies for efgartigimod administration and 
contraception requirements for men were updated to align with the safety information in the 
current efgartigimod IB. 
If appropriate, protocol text has been aligned with the most recent protocol version (amendment 
2 [v3.0], 27 Mar 2023) of the antecedent study ARGX-113-2009. 
The major changes from the original protocol v1.0 to protocol v2.0 are summarized 
in the following table. Minor editorial changes are not summarized in the table. Refer to the List 
of Abbreviations and Definitions of Terms for any undefined abbreviations or terms. 
Section 
Description of change 
Brief rationale 
5.2. Exclusion Criteria 
Added exclusion criterion 3.  
Health authority 
requested update to 
exclude participants 
who permanently 
discontinued IMP 
(efgartigimod PH20 SC 
or placebo) in 
ARGX-113-2009 
because of an AE 
considered related to 
IMP and for whom the 
benefit/risk balance is 
not considered positive. 
1.1. Synopsis 
The description of number of 
participants was revised per new 
exclusion criterion 3. 
1.3. Schedule of Activities 
(SoA), Table 1 and Table 2 
Brief physical examinations are now 
included at the week 4 and week 8 visits 
during the observation period for 
participants who do not require 
treatment with efgartigimod PH20 SC at 
rollover (Table 1). When participants 
start or continue efgartigimod SC 
treatment, brief physical examinations 
now occur at the week 8 visit (relative to 
day X) and every 16 weeks thereafter. 
Health authority 
requested update to 
increase the frequency 
of physical 
examinations. 
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Section 
Description of change 
Brief rationale 
Tables 1 and 2 were updated 
accordingly, and footnotes h and i were 
added in Table 2. These footnotes are 
also applicable to GTI assessments and 
QoL questionnaires, and footnote h to 
urine pregnancy tests. 
8.3.3. Electrocardiograms 
1.3. Schedule of Activities 
(SoA), Table 1 and Table 2 
ECG assessments are now included at 
the week 24 visit regardless of treatment 
(Table 1 and Table 2) and at the week 48 
visit when participants are on 
efgartigimod PH20 SC treatment or at 
the EDV, if applicable (Table 2). 
Tables 1 and 2 were updated 
accordingly, and footnote i was added in 
Table 2 at the week 24 visit during the 
observation period. 
Health authority 
requested update to 
allow for routine 
cardiac safety 
monitoring. 
4.2. Scientific Rationale for 
Study Design 
Clarification that participants who 
discontinued IMP (efgartigimod PH20 
SC or placebo) and required rescue 
therapy in ARGX-113-2009 can be 
eligible for this study. 
Provide clarification in 
response to a health 
authority request for 
information. 
1.1. Synopsis 
3. Objectives, Endpoints, and 
Estimands, Table 4: Study 
ARGX-113-2010 Objectives and 
Endpoints 
A footnote was added to secondary 
efficacy endpoints containing “while off 
OCS,” “while on minimal OCS 
therapy,” and “while off both OCS and 
efgartigimod PH20 SC” to clarify that 
those endpoint criteria can only be met 
when participants are off rescue therapy. 
6.3. Assignment to Study 
Intervention 
Table 6: Study Intervention 
Summary Table 
6.9. Prior and Concomitant 
therapy 
 
Status C2a (for participants who 
received rescue therapy in ARGX-113-
2009 and have not achieved CR or PR) 
was revised to allow the investigator to 
maintain, taper, or discontinue the 
participant’s rescue therapy (all or 
partly) while the participant requires 
treatment with efgartigimod, accounting 
for the type of rescue therapy received 
and the participant’s best interest. 
Health authority 
requested update to 
increase the 
investigator’s 
flexibility regarding the 
potential combination 
of rescue therapy and 
efgartigimod PH20 SC. 
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Section 
Description of change 
Brief rationale 
6.3. Assignment to Study 
Intervention 
Table 6: Study Intervention 
Summary Table 
Participants who received OCS, TCS, 
conventional immunosuppressants, 
tetracyclines with or without 
nicotinamide, and/or dapsone as rescue 
therapy in ARGX-113-2009 and have 
not achieved CR or PR may combine it 
with efgartigimod PH20 SC. Participants 
who received IV immunoglobulin may 
only start efgartigimod PH20 SC 
treatment 4 weeks after the start of their 
last IV immunoglobulin cycle. 
IV immunoglobulin 
was added as a 
nonimmunosuppressive 
rescue therapy in 
ARGX-113-2009 for 
participants who 
permanently 
discontinued IMP. 
6.3. Assignment to Study 
Intervention 
Table 6: Study Intervention 
Summary Table 
1.3. Schedule of Activities 
(SoA), Table 2 
Statuses E and F2 were updated to 
clarify that participants will be 
monitored for safety for 8 weeks after 
the participant’s final IMP 
administration. 
Health authority 
requested update to 
monitor participant 
safety after 
efgartigimod PH20 SC 
discontinuation. 
2.3.1. Risk Assessment, Table 3: 
Potential Risks and Mitigation 
Strategies, Infusion/injection-
related reactions 
The frequency of infusion/injection-
related reactions in the studies was 
added in Table 3. 
Alignment with the 
current efgartigimod 
IB. 
2.3.1. Risk Assessment, Table 3: 
Potential Risks and Mitigation 
Strategies, Injection-site 
reactions 
Injection-site reactions were added in 
Table 3 as a potential clinically 
significant risk that could be 
encountered and requires attention or 
special monitoring. 
Injection-site reactions 
are now defined as 
adverse events of 
clinical interest and 
will be monitored as 
such. 
2.3.1. Risk Assessment, Table 3: 
Potential Risks and Mitigation 
Strategies, Potential 
complications from exposure to 
OCS 
“Increase OCS doses” was deleted in 
Table 3 as a mitigation strategy. 
Increasing OCS doses 
is not a mitigation 
strategy for potential 
complications from 
exposure to OCS. 
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Section 
Description of change 
Brief rationale 
7.1.1. Permanent Discontinuation 
1.3. Schedule of Activities 
(SoA), Table 2 
The criteria requiring permanent IMP 
discontinuation were updated. 
Revision so that participants 
permanently discontinuing IMP attend 
an EDV and 2 safety follow-up visits 
over a period of 8 weeks after the 
participant’s final IMP administration. 
EDV column and associated footnote e 
were added in Table 2. 
Health authority 
requested update to 
monitor participant 
safety after 
efgartigimod PH20 SC 
discontinuation. 
7.2. Participant 
Discontinuation/Withdrawal 
From the Study 
1.3. Schedule of Activities 
(SoA), Table 1 and Table 2 
The criteria requiring withdrawal from 
the study were updated. 
Clarification that, if possible, an EDV 
and safety follow-up visit(s) should be 
conducted when the participant is 
withdrawn from the study. 
EDV column and associated footnote c 
were added in Table 1. 
Provide more 
information and 
specific instructions to 
the investigator and 
site staff about study 
withdrawal. 
 
9.5. Sample Size Determination 
Clarification that sample size 
determination is part of the antecedent 
study ARGX-113-2009. 
Ethics Committee 
requested update since 
the statement “not 
applicable” for the 
number of cases was 
unacceptable. 
10.4.2.2. Male Contraception 
Male contraception is no longer required 
in efgartigimod clinical studies.  
Nonclinical 
reproductive 
toxicology studies with 
efgartigimod indicated 
no influence on male or 
female reproductive 
potential or embryo-
fetal development. 
6.9.1. Oral Prednisone Tapering 
and Escalation 
Table 7 was revised to include minimum 
and maximum recommended doses for 
participants with body weights <45 kg 
and ≥110 kg, respectively. 
Provide additional, 
specific guidance for 
the investigator and 
site staff. 
Table 7: Concurrent Oral 
Prednisone Equivalent Doses (in 
Clarification that for these participants 
the investigator should propose an OCS 
dose per Table 7 and inform the medical 
 
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Section 
Description of change 
Brief rationale 
mg) Based on Participant Body 
Weight 
monitor to ensure consistency in the 
study. 
10.7. Appendix 7: Country-
specific Requirements 
10.7.1. China 
A table with recommendations on the 
concurrent oral methylprednisolone 
dosing regimen was added. 
Methylprednisolone 
rather than prednisone 
is prescribed in China. 
8.3.4.1. Substudy—Vaccination 
Response 
1.3. Schedule of Activities 
(SoA), Table 1 and Table 2 
Clarification that postvaccination blood 
sampling, as part of the vaccination 
substudy from ARGX-113-2009, can 
continue in this OLE study to assess 
humoral or cellular responses to 
vaccinations received in ARGX-113-
2009. 
Removed Table 1 original footnote e and 
Table 2 original footnote h. 
Provide explicit 
guidance for site staff. 
 
8.2.1.1. Assessment of BP 
Disease Status and OCS Dose 
Monitoring 
Added an instruction for the investigator 
to examine the participant for new 
lesions as this is part of the BP disease 
assessment. 
Ensure lesions 
assessment is 
performed. 
6.3. Assignment to Study 
Intervention 
Correction that a new treatment course 
of efgartigimod PH20 SC may be 
initiated in eligible participants until 
week 45 instead of week 44. 
Efgartigimod PH20 SC 
can be administered up 
to the week 48 visit to 
ensure a minimum of 
4 weeks of treatment. 
6.3. Assignment to Study 
Intervention 
Table 6: Study Intervention 
Summary Table 
Clarification that TCS may be used to 
treat localized lesions rather than 
transient lesions at the investigator’s 
discretion. 
Provide specific 
guidance for the 
investigator and site 
staff. 
1.3. Schedule of Activities 
(SoA), Table 1 and Table 2 
Table 1 footnote d (previously c) and 
Table 2 footnote f (previously e) were 
revised to explain in which situations a 
UNS is performed (including a notable 
weight change) and that the investigator 
decides which assessments to conduct 
based on the purpose of the UNS. 
Provide additional, 
specific information for 
the investigator and 
site staff. 
1.3. Schedule of Activities 
(SoA), Table 2 
8.3.1. Physical Examinations 
Table 2 footnote g has been added to 
clarify when to perform a brief physical 
examination instead of a complete 
physical examination. This instruction 
Facilitate protocol 
compliance by the 
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Section 
Description of change 
Brief rationale 
was removed from the body protocol 
text. 
investigator and site 
staff 
4.1. Overall Design 
Text was added to specify that this study 
will remain open for a maximum of 
2 years after completion of 
ARGX-113-2009. 
Compliance with 
argenx continued 
access policy. 
6.7. Continued Access to IMP 
After the End of the Study 
The following text has been removed: 
“argenx will comply with all local laws 
and regulations to ensure participants 
have access to care that has been 
medically identified as essential” 
because argenx cannot guarantee 
continued access for IMP at the end of 
the study. 
6.9. Prior and Concomitant 
Therapy 
 
Added that the brand name of vaccines 
received at baseline or during the study 
should be recorded. 
Missing information 
from the original 
protocol version. 
The following text has been added to the 
list of medications prohibited when the 
participant receives efgartigimod PH20 
SC: “any other biologic agent or 
experimental/study IMP.” 
Ensure individuals 
participating in another 
interventional research 
study are excluded 
from this study. 
8.3.2. Vital Signs 
Removed the requirement that 
participants must be seated while blood 
pressure and pulse rate are assessed.  
The participant’s 
position during 
measurement of blood 
pressure and pulse rate 
is not relevant in this 
study. 
Definitions of Terms 
Definition of concurrent BP therapy was 
updated:  
• “TCS” was added  
• “and continued after rollover to 
ARGX-113-2010” was removed 
because IV immunoglobulin can be 
part of the rescue therapy used in 
ARGX-113-2009. 
Alignment with the 
revised definitions and 
updates to allowed 
rescue therapy in 
ARGX-113-2009 
protocol amendment 2 
(v3.0). 
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Section 
Description of change 
Brief rationale 
The definition of CR was revised to: 
“The absence of new lesions, complete 
healing of existing lesions, and absence 
of pruritus (except postinflammatory, 
including hypo/hyperpigmentation or 
skin damage)” 
The definition of relapse was aligned 
with consensus terminology. 
10.1.1. Regulatory and Ethical 
Considerations 
The section was completed with 
regulatory or ethical considerations for 
study conduct. 
Deletion error from the 
original protocol 
version. 
10.1.3. Informed Consent Process The following statement was removed: 
“Participants who are rescreened are 
required to sign a new ICF (Section 
5.4).” 
(Re)screening does not 
apply for this OLE 
study. 
2.2. Background 
2.3. Benefit/Risk Assessment 
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. 
6.4. Blinding 
 are administered on 
days 1 and 8 and not at baseline as was 
described in the original protocol. 
Correction. 
 
 
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10.7. 
Appendix 7: 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. 
10.7.1. 
China 
PD and immunogenicity blood samples that are collected from participants in China 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 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 6.9.1). 
Refer to Table 9 for the concurrent oral methylprednisolone dose regimen. 
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b The investigator should not deviate from the concurrent oral methylprednisolone dose levels specified in the table, except if the participant’s safety could be 
compromised. 
 
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11. 
REFERENCES 
1. Murrell DF, Daniel BS, Joly P, et al. Definitions and outcome measures for bullous 
pemphigoid: recommendations by an international panel of experts. J Am Acad Dermatol. 
2012;66(3):479-485. 
2. Schmidt E, Obe K, Bröcker EB, Zillikens D. Serum levels of autoantibodies to BP180 
correlate with disease activity in patients with bullous pemphigoid. Arch Dermatol. 
2000;136(2):174-178. 
3. Masmoudi W, Vaillant M, Vassileva S, et al. International validation of the Bullous 
Pemphigoid Disease Area Index severity score and calculation of cut-off values for 
defining mild, moderate and severe types of bullous pemphigoid. Br J Dermatol. 
2021;184(6):1106-1112. 
4. 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. 
5. 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. 
6. 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. 
7. Jenkins HH, Spencer ED, Weissgerber AJ, Osborne LA, Pellegrini JE. Correlating an 11-
point verbal numeric rating scale to a 4-point verbal rating scale in the measurement of 
pruritus. J Perianesth Nurs. 2009;24(3):152-155. 
8. Phan NQ, 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. 
9. 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. 
10. Sebaratnam DF, Hanna AM, Chee S, 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. 
11. 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 Pract. 2021;9(1):365-372.e5. 
12. Center for Drug Evaluation and Research (CDER), Center for Biologics Evaluation and 
Research (CBER). Immunogenicity Testing of Therapeutic Protein Products — 
Developing and Validating Assays for Anti-Drug Antibody Detection. Guidance for 
Industry. January 2019. Accessed 09 Aug 2022. 
https://www.fda.gov/media/119788/download 
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13. Clinical Trials Facilitation and Coordination Group (CTFG). Recommendations related to 
contraception and pregnancy testing in clinical trials. Version 1.1. 21 Sep 2020. 
Accessed: 09 Aug 2022. 
https://legemiddelverket.no/Documents/Godkjenning/Klinisk%20utprøving/2014_09_H
MA_CTFG_Contraception_guidance%20Version%201.1.pdf 
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