A Low-Interventional Study Of AAV9 Neutralizing Antibody Seroconversion in Household Contacts of Participants Within the C3391003 Clinical Trial
Conditions: Household Contacts
Sponsor: Pfizer

Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
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Title Page
A LOW-INTERVENTIONAL STUDY OF AAV9 NEUTRALIZING ANTIBODY 
SEROCONVERSION IN HOUSEHOLD CONTACTS OF PARTICIPANTS WITHIN 
FORDADISTROGENE MOVAPARVOVEC CLINICAL TRIALS
Compound Number:
N/A
Compound Name:
N/A
US IND Number:
017598
EudraCT Number:
N/A
Protocol Number:
C3391007
Phase:
N/A
Short Title: A Low-Interventional Study to Assess Development of Neutralizing 
Antibodies (NAbs) to AAV9 in Household Contacts of Duchenne Muscular Dystrophy
Patients Treated with Fordadistrogene Movaparvovec
This document and accompanying materials contain confidential information belonging to Pfizer.  Except as 
otherwise agreed to in writing, by accepting or reviewing these documents, you agree to hold this 
information in confidence and not copy or disclose it to others (except where required by applicable law) or 
use it for unauthorized purposes.  In the event of any actual or suspected breach of this obligation, Pfizer 
must be promptly notified.
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
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Protocol Amendment Summary of Changes Table
Document History
Document
Version Date
Summary and Rationale for Changes
Amendment 1
05 April 2022

Added inclusion of household 
contacts of patients dosed in 
interventional studies C3391001, 
C3391002, and C3391008 
(Multiple Sections).

Study drug name updated from PF-
06939926 to fordadistrogene 
movaparvovec (Multiple Sections).

Clarified that informed consent 
may be conducted remotely 
(Sections 1.3 and 8). 

Updated Clinical Overview of 
fordadistrogene movaparvovec 
studies with latest information 
(Section 2.2.2).

Moved content to current LIS1 
protocol template version (dated 
Dec 2020) and updated text and 
formatting accordingly (Multiple 
Sections).

Added Scientific Rationale for 
study design per new protocol 
template requirement (Section 
4.2).

Added definition for End of Study 
per new protocol template 
requirement (Section 4.4).

Modified definition of Screen 
Failure for clarity (Section 5.4).

Removed requirement for topical 
analgesic prior to blood draws in 
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
CT45-GSOP-RF15A 1.0 Low-Interventional Study 1 (LIS1) Protocol Template 01-Dec-2020
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Document History
Document
Version Date
Summary and Rationale for Changes
order to decrease operational 
complexity (Sections 8 and 8.9.1).

Updated table of 95% CIs for the 
estimate of the proportion of 
participants who are negative for 
NAb to AAV9 at Baseline and 
develop NAb to AAV9 post-
Baseline for various numbers of 
enrolled participants (Section 9.2).

Administrative changes were made 
to enhance readability.
Original protocol
19 March 2020
N/A
This amendment incorporates all revisions to date, including amendments made at the 
request of country health authorities and IRBs/ECs, and any protocol administrative 
clarification letters. 
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
CT45-GSOP-RF15A 1.0 Low-Interventional Study 1 (LIS1) Protocol Template 01-Dec-2020
Page 4 of 54
TABLE OF CONTENTS
LIST OF TABLES.....................................................................................................................7
1. PROTOCOL SUMMARY.....................................................................................................8
1.1. Synopsis ....................................................................................................................8
1.2. Schema ....................................................................................................................11
1.3. Schedule of Activities .............................................................................................12
2. INTRODUCTION ...............................................................................................................13
2.1. Study Rationale .......................................................................................................13
2.2. Background .............................................................................................................13
2.2.1. NonClinical Overview................................................................................14
2.2.2. Clinical Overview.......................................................................................14
2.3. Benefit/Risk Assessment.........................................................................................15
3. RESEARCH QUESTIONS, OBJECTIVES AND ENDPOINTS.......................................15
3.1. Variables..................................................................................................................16
4. STUDY DESIGN.................................................................................................................17
4.1. Overall Design.........................................................................................................17
4.2. Scientific Rationale for Study Design.....................................................................17
4.2.1. Limitations of the Study Design and Methods ...........................................18
4.3. Justification for Dose ..............................................................................................18
4.4. End of Study Definition ..........................................................................................18
5. STUDY POPULATION......................................................................................................18
5.1. Inclusion Criteria.....................................................................................................18
5.2. Exclusion Criteria....................................................................................................19
5.3. Lifestyle Considerations..........................................................................................19
5.4. Screen Failures ........................................................................................................19
6. STUDY INTERVENTIONS ...............................................................................................19
6.1. Study Intervention(s)...............................................................................................19
6.1.1. Performance or Administration of Diagnostic or Monitoring Study 
Interventions ....................................................................................................19
6.2. Methods to Minimize Bias ......................................................................................19
7. PARTICIPANT DISCONTINUATION/WITHDRAWAL FROM STUDY......................20
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Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
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7.1. Participant Discontinuation/Withdrawal From the Study.......................................20
7.1.1. Withdrawal of Consent...............................................................................20
7.2. Lost to Follow-up....................................................................................................20
8. STUDY ASSESSMENTS AND PROCEDURES...............................................................21
8.1. Efficacy Assessments..............................................................................................22
8.2. Safety Assessments .................................................................................................22
8.2.1. Weight Measurement..................................................................................22
8.2.2. Protocol-Required Clinical Safety Laboratory Assessments......................22
8.2.3. Baseline Characteristics..............................................................................22
8.3. Adverse Events and Serious Adverse Events..........................................................23
8.3.1. Time Period and Frequency for Collecting AE and SAE Information.......23
8.3.1.1. Reporting SAEs to Pfizer Safety...............................................24
8.3.1.2. Recording Nonserious AEs and SAEs on the CRF...................24
8.3.2. Method of Detecting AEs and SAEs ..........................................................24
8.3.3. Follow-up of AEs and SAEs.......................................................................24
8.3.4. Regulatory Reporting Requirements for SAEs...........................................25
8.3.5. Exposure During Pregnancy or Breastfeeding, and Environmental 
Exposure ..........................................................................................................25
8.3.5.1. Exposure During Pregnancy......................................................25
8.3.5.2. Exposure During Breastfeeding ................................................26
8.3.5.3. Environmental Exposure...........................................................27
8.3.6. Cardiovascular and Death Events...............................................................27
8.3.7. Disease-Related Events and/or Disease-Related Outcomes Not 
Qualifying as AEs or SAEs..............................................................................27
8.3.8. Adverse Events of Special Interest.............................................................27
8.3.8.1. Lack of Efficacy........................................................................27
8.3.9. Medical Device Deficiencies......................................................................27
8.4. Treatment of Overdose............................................................................................28
8.5. Pharmacokinetics ....................................................................................................28
8.6. Pharmacodynamics..................................................................................................28
8.7. Genetics...................................................................................................................28
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
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8.8. Biomarkers ..............................................................................................................28
8.8.1. Banked Biospecimens.................................................................................28
8.9. Immunogenicity Assessments.................................................................................29
8.9.1. Blood Samples for Immunogenicity and Vector DNA Measurement........29
8.10. Health Economics .................................................................................................29
9. STATISTICAL CONSIDERATIONS ................................................................................29
9.1. Statistical Hypotheses .............................................................................................29
9.2. Sample Size Determination.....................................................................................29
9.3. Data Management ...................................................................................................30
9.4. Case Report Forms/Data Collection Tools/Electronic Data Record.......................30
9.5. Data Analysis ..........................................................................................................31
9.6. Interim Analyses .....................................................................................................32
9.7. Data Monitoring Committee or Other Independent Oversight Committee.............32
10. SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS..........................................................................................................33
10.1. Appendix 1: Regulatory, Ethical, and Study Oversight Considerations...............33
10.1.1. Regulatory and Ethical Considerations ....................................................33
10.1.1.1. Reporting of Safety Issues and Serious Breaches of the 
Protocol or ICH GCP.........................................................................33
10.1.2. Responsible Parties...................................................................................34
10.1.3. Informed Consent Process ........................................................................34
10.1.4. Data Protection .........................................................................................35
10.1.5. Dissemination of Clinical Study Data ......................................................35
10.1.6. Data Quality Assurance ............................................................................37
10.1.7. Source Documents....................................................................................38
10.1.8. Study and Site Start and Closure ..............................................................38
10.1.9. Publications by Investigators....................................................................39
10.2. Appendix 2: Adverse Events: Definitions and Procedures for Recording, 
Evaluating, Follow-up, and Reporting ......................................................................41
10.2.1. Definition of AE .......................................................................................41
10.2.2. Definition of SAE.....................................................................................42
10.2.3. Recording/Reporting and Follow-up of AEs and/or SAEs.......................45
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
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10.2.4. Reporting of SAEs....................................................................................49
10.3. Appendix 3: Liver Safety: Suggested Actions and Follow-up Assessments ........50
10.4. Appendix 4: Abbreviations ...................................................................................52
11. REFERENCES ..................................................................................................................54
LIST OF TABLES
Table 1.
95% CI of the Estimate of the Proportion of Participants who are 
NAb Seronegative to AAV9 at Baseline and who Seroconvert to 
AAV9 Post-Baseline.................................................................................30
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
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1. PROTOCOL SUMMARY
1.1. Synopsis
Short Title
A Low-Interventional Study to Assess Development of Neutralizing Antibodies (NAbs) to 
AAV9 in Household Contacts of Duchenne Muscular Dystrophy Patients Treated with 
Fordadistrogene Movaparvovec
Rationale
At present, there is uncertainty regarding the risk of developing NAbs to AAV9 for a 
household contact of a patient who has received an AAV9 based gene therapy and may be 
shedding vial vector. The result is that families must consider this unknown risk when 
considering this therapy for others that may also be treated in the future, such as siblings, or 
when considering participation in activities for DMD patients who may want to receive AAV 
gene therapy in the future, or when considering attendance at camps or conferences.
The results of this study will help quantify the risk of developing NAbs to AAV9 in 
household contacts of patients treated with fordadistrogene movaparvovec.  This will be 
valuable information to future patients, families, and perhaps even casual contacts of DMD 
patients because of the theoretical possibility of losing access to an AAV9-based gene 
therapy by developing NAbs to AAV9 after contact with other treated patients.
Banked biospecimens will be collected and stored for further analyses which may, for
example, provide greater understanding of fordadistrogene movaparvovec research questions 
and objectives.
Objectives and Endpoints
Primary Objective:
Primary Endpoint:
To quantify the proportion of participants 
(previously seronegative for NAb to 
AAV9) who develop NAb to AAV9 
(ie, seroconversion).
Development of NAb to AAV9 (ie, NAb 
seroconversion) as defined by an increase 
of ≥6-fold above Baseline titer in 
participants with a detectable, but negative 
test (ie, titer ≥1 and <4) for NAb to AAV9 
at Baseline. If there is an undetectable titer 
at Baseline (ie, titer <1), then development 
of NAb to AAV9 as defined by a NAb to 
AAV9 titer ≥6.
Secondary Objective:
Secondary Endpoint:
To quantify the proportion of participants 
(previously seronegative for ADA to 
AAV9) who develop ADA to AAV9.
Development of ADA to AAV9 (ie, ADA 
seroconversion) defined by a titer ≥300 in 
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
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participants with a negative test (ie, titer 
<50) for ADA to AAV9 at Baseline.
Exploratory Objectives:
Exploratory Endpoints:
To quantify the proportion of participants 
(previously seropositive for NAb to AAV9) 
who have an increase in the NAb to AAV9 
titer.
NAb to AAV9 titer ≥6-fold higher than 
Baseline titer in participants who are 
seropositive (ie, titer ≥4) for NAb to 
AAV9 at Baseline.
To quantify the proportion of participants 
(previously seropositive for ADA to 
AAV9) who have an increase in the ADA 
to AAV9 titer.
ADA to AAV9 titer ≥6-fold higher than 
Baseline titer in participants who are 
seropositive (ie, titer ≥50) for ADA to 
AAV9 at Baseline.
To quantify the proportion of participants 
who seroconvert and have detectable 
fordadistrogene movaparvovec vector DNA 
in blood.
Detectable fordadistrogene movaparvovec
vector DNA in participants who 
seroconvert via either ADAs or NAbs.
Overall Design
This single center, low-interventional study to include approximately 50 to 250 participants 
is designed to estimate the likelihood of developing NAbs to AAV9 because of exposure to 
shed viral vector material released by a DMD patient treated with fordadistrogene 
movaparvovec in clinical studies.  This study will include participants who live or work in 
the same household as a participant in one of the fordadistrogene movaparvovec 
interventional studies, which may include Study C3391003, C3391002, C3391008, or 
C3391001. Up to 5 participants from the same household may be enrolled.  Eligible 
participants will undergo phlebotomy provided by a Home Health Care Vendor at three home 
visits as specified in the Schedule of Activities.  As a control, seroconversion or rise of 
antibody titer against other AAVs may also be quantified.
Number of Participants
Approximately 50 to 250 participants will be enrolled.  Table 1 shows the expected precision, 
defined as the upper and lower 95% confidence limits, of the estimate of the proportion of 
participants who are negative for NAb to AAV9 at Baseline and who develop NAb to AAV9 
post-Baseline for various numbers of enrolled participants.  These calculations assume that 
75% of the participants will be seronegative for NAb to AAV9 at Baseline.
Study Cohorts and Duration of Study Participation
The total duration of participation in the study is approximately 4 months, including up to 48 
days for the screening/baseline period and 56 + 10 days of follow-up after the interventional 
study patient is dosed with investigational product. The screening/baseline period may be 
extended if there are delays in the interventional studies.
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Data Monitoring Committee or Other Independent Oversight Committee: No
Statistical Methods
Detailed methodology for summary and statistical analyses of data collected in this study will 
be documented in the SAP, which will be dated, filed, and maintained by the sponsor.  The 
SAP may modify the plans outlined in the protocol; any major modifications of primary 
endpoint definitions or their analyses would be reflected in a protocol amendment.
For the primary, secondary, and each of the exploratory endpoints listed in Section 3, the 
proportion (and 95% CI) of C3391007 participants will be estimated for 2 groups of 
participants:

fordadistrogene movaparvovec: household contacts of patients in interventional 
studies C3391002, C3391003, C3391001, and C3391008 

placebo: household contacts of patients in interventional studies C3391002 and 
C3391003 
using generalized estimating equations methods with study as covariate to account for 
correlated responses within the same household. A binomial distribution with a log link and 
an exchangeable correlation matrix within each household (ie, between any two members of 
a household the correlation is the same) will be used.  Proportions and 95% confidence 
intervals will be provided separately for each visit (except for Detectable fordadistrogene 
movaparvovec vector DNA in participants who seroconvert via either ADAs or NAbs) and 
overall at any time during the study.
Incidence of AEs will be summarized/listed.
Pharmacogenomic or biomarker data from banked biospecimens will be collected pursuant to 
local regulations/IRB during or after the trial and retained for future analyses; the results of 
such analyses are not planned to be included in the CSR.
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1.2. Schema
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1.3. Schedule of Activities
The SoA table provides an overview of the protocol visits and procedures.  Refer to the STUDY ASSESSMENTS AND 
PROCEDURES section of the protocol for detailed information on each procedure and assessment required for compliance with the 
protocol.
The investigator may schedule visits (unplanned visits) in addition to those listed in the SoA table, in order to conduct evaluations or 
assessments required to protect the well-being of the participant.
Visit Identifier
Abbreviations used in this table may be found in Section 10.4.
Visit 1
(Screening and Baseline visit) a
N/A
Visit 2c
Visit 3
Visit 4
Visit Day (±days visit window) b
-48 to -1
Day 1
Day 14 
(+2 days)
Day 28
(±8 days)
Day 56
(±10 days)
Informed consent/assentc
X
Review of inclusion/exclusion criteria
X
X
Medical history
X
Demographic information
X
Extent of contact with the patient of the interventional study
X
X
Weight measurement
X
Concomitant treatments
X
X
X
Serious and non-serious adverse event monitoring
X
X
X
X
Blood Samples for NAb and ADA to AAV9d
X
X
X
fordadistrogene movaparvovec vector DNA
X
X
X
Banked biospecimense
X
Enrollment
X
Home visitf
X
X
X
a.
Screening/baseline period of this study may be extended if there are delays in the interventional study.
b.
Day relative to first dose of IP administration (Day 1) of the interventional study patient who is in the same household as the main study participant.
c.
May be conducted via a phone call or other remote communication.
d.
Unscheduled/additional blood draws for NAb and ADA to AAV9 may be required if the quality of the scheduled collected sample is deemed unacceptable 
for analysis.
e.
Biobank specimens will only be drawn in participants who weigh >20 kg.
f.
Study procedures will be conducted by the home health care vendor at the participant’s home, and/or by the Investigator via remote communication.
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2. INTRODUCTION
Duchenne muscular dystrophy (DMD) is a severe, X-linked, progressive neuromuscular 
disease affecting approximately 1 in 3600 to 9300 live male births.1  It is caused by 
mutations in the dystrophin gene that eliminate or severely reduce the expression of 
functional dystrophin protein.2  The near lack of the dystrophin protein in skeletal muscles, 
including those required for respiration and in the heart, leads to muscle degeneration which 
results in loss of ambulation and premature death.3
Fordadistrogene movaparvovec is a candidate disease modifying gene therapy treatment for 
DMD that has the potential to slow the disease progression, improve motor function, and/or 
normalize motor development milestones.  Fordadistrogene movaparvovec is a rAAV 
serotype 9 (AAV9) vector expressing a codon-optimized, miniaturized version of the 
dystrophin gene (“mini-dystrophin”).  Due to the existence of AAV9 in nature, about 15-35% 
of adults have pre-existing neutralizing antibodies to the AAV9 capsid.4,5,6
2.1. Study Rationale
At present, there is uncertainty regarding the risk of developing NAbs to AAV9 for a 
household contact of a patient who has received an AAV9 based gene therapy and may be 
shedding viral vector. The result is that families must consider this unknown risk when 
considering this therapy for others that may also be treated in the future, such as siblings, or 
when considering participation in activities for DMD patients who may want to receive AAV 
gene therapy in the future, or when considering attendance at camps or conferences.
The results of this study will help quantify the risk of developing NAbs to AAV9 in 
household contacts of patients treated with fordadistrogene movaparvovec.  This will be 
valuable information to future patients, families, and perhaps even casual contacts of DMD 
patients because of the theoretical possibility of losing access to an AAV9-based gene 
therapy by developing NAbs to AAV9 after contact with other treated patients.
2.2. Background
Viral vectors are metabolized by the same general processes as naturally occurring 
adenoviruses.  Although naturally occurring viruses utilize the cellular machinery to 
reproduce viral particles using the viral DNA, rAAVs have eliminated this DNA, and 
therefore, new viral particles are not produced.
Viral vector shedding has been investigated in the clinical studies of other gene therapies 
utilizing AAV.  LUXTURNA® is an approved AAV2-based gene therapy product for 
treatment of an inherited retinal disease and is injected intraocularly.7  Shedding data were 
reported only for tears.  In 29 subjects receiving LUXTURNA, peak levels of vector DNA 
were detected in tear samples on Day 1 post-injection, after which no vector DNA was 
detected in a majority of the subjects (8 of 13). Three (3 [10%]) subjects had vector DNA in 
tear samples until Day 3 post-injection, and 2 (7%) subjects had vector DNA in tear samples 
for approximately 2 weeks post-injection.  In 2 (7%) subjects, vector DNA was detected in 
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tear samples from the uninjected (or previously injected) eye until Day 3 post-injection.  
Vector DNA was detected in serum in 3/29 (10%) subjects, and 2 of these had vector DNA 
detected in tear samples up to Day 3.  ZOLGENSMA® is an approved AAV9-based gene 
therapy product for the treatment of a neuromuscular disease and is administered 
intravenously.8  Shedding data from 5 subjects is described in the prescribing information, 
demonstrating that the vector DNA was shed in saliva, urine, and stool after infusion of 
ZOLGENSMA.  The vector DNA concentration in saliva was low on Day 1 after infusion 
and declined to undetectable levels within 3 weeks.  In urine, the vector DNA concentration 
was very low on Day 1 after infusion and declined to undetectable levels within 1 to 2 weeks.  
In stool, the vector DNA concentration was much higher than in saliva or urine for 1 to 2 
weeks after infusion and declined to undetectable levels by 1 to 2 months after infusion.
The available non-clinical and clinical data describing viral vector shedding kinetics suggests 
that DNA is detectable in multiple bodily fluids including plasma, tears, saliva, urine, and 
stool following IV infusion of rAAV and that it is usually cleared from these matrices within 
approximately 40 days.9 Since the kinetics are likely dependent upon the specific rAAV 
serotype as well as on the dose administered, the viral vector shedding profile of 
fordadistrogene movaparvovec will be determined within ongoing and planned clinical 
studies.
2.2.1. NonClinical Overview
Fluid samples (serum, urine, and saliva) were collected from 7 GRMD dogs treated with 
fordadistrogene movaparvovec to determine the level and duration of viral vector shedding.  
None of these dogs reached sexual maturity during the study, so semen samples were not 
collected.  In samples collected before treatment, no vector genomes were detected.  At 3 
days post infusion (p.i.), the first timepoint assessed, the number of vector genomes detected 
in serum ranged from 0.01 to 0.32% of the total injected dose.  This value decreased to 
≤0.001% of the total injected dose by 7 days p.i. in saliva and by 28 days in serum and urine. 
With the exception of a single dog urine sample collected at 6 months p.i., all of the other 
dogs (6 out of 7) had negative urine samples after day 21.
2.2.2. Clinical Overview
As of December 2021, there are 4 ongoing or planned interventional studies evaluating
fordadistrogene movaparvovec for the treatment of DMD patients:

C3391001 is a Phase 1b, first-in-human, open-label, single ascending dose study in 
ambulatory and non-ambulatory patients with DMD.

C3391003 is a Phase 3, global, multi-center, randomized, double blind, placebo-
controlled study in ambulatory DMD patients.

C3391002 is a Phase 3, global, multicenter, randomized, double blind, placebo-
controlled study in non-ambulatory DMD patients.
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Fordadistrogene movaparvovec (PF-06939926)
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
C3391008 is a Phase 2, global, multicenter, open label, study in patients with early 
stage DMD.
Viral vector shedding will be evaluated for fordadistrogene movaparvovec in C3391001 and 
C3391003.  Whole blood, saliva, and urine samples will be collected in patients from 
interventional studies C3391001 and C3391003. This evaluation is designed to provide 
information about 2 factors that contribute to the risk of exposure to viral vectors for 
untreated individuals: the magnitude of viral vector shedding, and the duration of the period 
in which the vector is present in bodily secretions. Individuals living or working in the same 
household of a DMD patient who has recently received fordadistrogene movaparvovec may 
be exposed to shed viral material. Whilst this does not pose a risk of infection, those 
individuals, who had not previously been environmentally exposed to AAV9, in consequence 
may develop neutralizing antibodies (NAbs) or other binding antibodies (anti-drug 
antibodies; ADAs) against the viral vector (seroconversion). NAb seroconversion to AAV9 
would likely result in exclusion from AAV9-based gene therapies in the future. In particular, 
an untreated DMD patient who seroconverted would likely be excluded from receiving 
fordadistrogene movaparvovec, therefore profoundly impacting that patient’s potential 
treatment option.
2.3. Benefit/Risk Assessment
Considering the measures taken to minimize risk to participants participating in this study, 
the potential risks identified in association with the blood draws (the study interventions) are 
justified by the anticipated benefits that may be afforded to household contacts of patients
with DMD treated with a gene therapy.
Exposure to shed viral material is not anticipated to pose a safety risk due to the following 
reasons: (1) Only a small portion of fordadistrogene movaparvovec is expected to be shed 
from participants in C3391003 in comparison to the IV dose received;10 (2) The amount of 
functional, intact fordadistrogene movaparvovec taken up through exposure to shed viral 
material by C3391007 participants is expected to be negligible; (3) fordadistrogene 
movaparvovec is replication incompetent. Thus, there is no anticipated risk for a viral 
infection as would be expected from exposure to a wildtype AAV. The only risk for 
participants in C3391007 is to develop antibodies or increase their antibody titer in response 
to exposure to minute amounts of shed viral material from an interventional study patient. 
The minimal immune response is not expected to manifest with any symptoms.
3. RESEARCH QUESTIONS, OBJECTIVES AND ENDPOINTS
Objectives
Endpoints
Primary:
Primary:
To quantify the proportion of participants 
(previously seronegative for NAb to AAV9) 
who develop NAb to AAV9 
(ie, seroconversion).
Development of NAb to AAV9 (ie, NAb 
seroconversion) as defined by an increase 
of ≥6-fold above Baseline titer in 
participants with a detectable, but negative 
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Objectives
Endpoints
test (ie, titer ≥1 and <4) for NAb to AAV9 
at Baseline. If there is an undetectable titer 
at Baseline (ie, titer <1), then development 
of NAb to AAV9 as defined by a NAb to 
AAV9 titer ≥6.
Secondary:
Secondary:
To quantify the proportion of participants 
(previously seronegative for ADA to AAV9) 
who develop ADA to AAV9.
Development of ADA to AAV9 (ie, ADA 
seroconversion) defined by a titer ≥300 in 
participants with a negative test (ie, titer 
<50) for ADA to AAV9 at Baseline.
Exploratory:
Exploratory:
To quantify the proportion of participants 
(previously seropositive for NAb to AAV9) 
who have an increase in the NAb to AAV9 
titer.
NAb to AAV9 titer ≥6-fold higher than 
Baseline titer in participants who are 
seropositive (ie, titer ≥4) for NAb to AAV9 
at Baseline.
To quantify the proportion of participants 
(previously seropositive for ADA to AAV9) 
who have an increase in the ADA to AAV9 
titer.
ADA to AAV9 titer ≥6-fold higher than 
Baseline titer in participants who are 
seropositive (ie, titer ≥50) for ADA to 
AAV9 at Baseline.
To quantify the proportion of participants 
who seroconvert and have detectable 
fordadistrogene movaparvovec vector DNA 
in blood.
Detectable fordadistrogene movaparvovec
vector DNA in participants who 
seroconvert via either ADAs or NAbs.
3.1. Variables
Variable
Role
Data source(s)
Operational 
definition
Demographic 
information
Participant baseline 
characteristic
CRF
N/A
Age of interventional
study patient and 
C3391007 participant 
Participant baseline 
characteristic
CRF
N/A
Extent of contact 
with the patient in the 
interventional study
Participant 
characteristic
CRF
N/A
Weight 
Participant baseline 
characteristic
CRF
N/A
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Variable
Role
Data source(s)
Operational 
definition
Concomitant 
treatments
Participant baseline 
characteristic
CRF
N/A
Medical history
Participant baseline 
characteristic
CRF
N/A
Adverse events (AEs)
Safety assessment
CRF
N/A
Blood samples for 
NAb to AAV9, ADA 
to AAV9 and 
fordadistrogene 
movaparvovec vector 
DNA
Outcome to assess 
primary, secondary,
and exploratory 
objectives
Central laboratory 
and CRO data 
transfer files
N/A
4. STUDY DESIGN
4.1. Overall Design
This single center, low-interventional study to include approximately 50 to 250 participants 
is designed to estimate the likelihood of developing NAbs to AAV9 because of exposure to 
shed viral vector material released by a DMD patient treated with fordadistrogene 
movaparvovec in clinical studies. This study will include participants who live or work in 
the same household as a patient in one of the fordadistrogene movaparvovec interventional 
studies which may include Study C3391003, C3391002, C3391008, or C3391001. Given the 
timing and logistics of the interventional studies, some may have no household contacts 
participating in C3391007. Up to 5 participants from the same household may be enrolled.  
Eligible participants will undergo phlebotomy provided by a Home Health Care Vendor at 
three home visits as specified in the Schedule of Activities. As a control, seroconversion or 
rise of antibody titer against other AAVs may also be quantified.
The total duration of participation in the study is approximately 4 months, including up to 48 
days for the screening/baseline period and 56 + 10 days of follow-up after the interventional 
study patient is dosed with investigational product. The screening/baseline period may be 
extended if there are delays in the interventional studies.
The single center conducting this study is located in the United States.
4.2. Scientific Rationale for Study Design
People working or living in the same household of patients who are enrolled in an 
interventional study of fordadistrogene movaparvovec were chosen as the participant 
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population for this study as they are expected to have the most contact with those patients 
and therefore most likely to be exposed to shed viral vector material.
Blood was chosen in this study as the bodily fluid with which to investigate seroconversion 
in household contacts of patients who have been dosed with fordadistrogene movaparvovec
because it is the most sensitive to detect NAbs.
Banked biospecimens will be collected and stored for further analyses which may, for 
example, provide greater understanding of fordadistrogene movaparvovec research questions 
and objectives.
4.2.1. Limitations of the Study Design and Methods
Not applicable.
4.3. Justification for Dose
Not applicable.
4.4. End of Study Definition
A participant is considered to have completed the study if they have completed all visits and
procedures in the SoA.
The end of the study is defined as the date of study completion for the last participant in the 
study.
5. STUDY POPULATION
This study can fulfill its objectives only if appropriate participants are enrolled.  The 
following eligibility criteria are designed to select participants for whom participation in the 
study is considered appropriate.
Prospective approval of protocol deviations to recruitment and enrollment criteria, also 
known as protocol waivers or exemptions, is not permitted.
5.1. Inclusion Criteria
Participants are eligible to be included in the study only if all of the following criteria apply:
1. Males or females who weigh at least 9 kg.
2. Anticipated to be living or working in the same household (≥10 hours per week and 
expected to have direct contact) with a patient in one of the fordadistrogene 
movaparvovec interventional studies (C3391003, C3391002, C3391008, or C3391001) 
for at least 4 months from the time of the screening visit of this study.
3. The interventional study patient is dosed with IP after the Baseline Visit.
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4. Evidence of a signed and dated ICD or assent indicating that the participant (or a legally 
acceptable representative) has been informed of all pertinent aspects of the study.
5. Willing and able to comply with scheduled visits, laboratory tests, and other study 
procedures.
5.2. Exclusion Criteria
Participants are excluded from the study if any of the following criteria apply:
1. Prior treatment with gene therapy utilizing AAV vectors of any serotype.
2. Living or working in a household where 5 other participants are already participating in 
this study (C3391007).
3. Investigator site staff or Pfizer employees directly involved in the conduct of the study, 
site staff otherwise supervised by the Investigator, and their respective family members.
5.3. Lifestyle Considerations
No restrictions are required.
5.4. Screen Failures
Screen failures are defined as participants who consent to participate in this study but are not 
subsequently enrolled in the study.
Screen failure data are collected and remain as source and are not reported to the clinical 
database.
6. STUDY INTERVENTIONS
In this study, there are no therapeutic study interventions, however the study does involve 
protocol-required diagnostic or monitoring procedures (study interventions) that are 
considered to be low risk or burden to the study participant, specifically blood draws.
6.1. Study Intervention(s)
6.1.1. Performance or Administration of Diagnostic or Monitoring Study Interventions
Not applicable.
6.2. Methods to Minimize Bias
To maintain the blinded nature of interventional studies C3391003 and C3391002, all 
C3391007 study participants and investigators as well as the sponsor will remain blinded to 
the Cohort assignment of the C3391002 or C3391003 study participant in the same 
household until C3391003 and C3391002 becomes unblinded.  Additionally, the detailed 
individual results of NAb and ADA to AAV and fordadistrogene movaparvovec vector DNA 
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will be considered sensitive clinical data and will not be shared with the participants, 
investigators, or the sponsor until any blinded interventional study that contributes to this 
study becomes unblinded.   Data results from this study of household contacts of DMD 
patients from the open-label interventional studies C3391008 and C3391001 will not be 
blinded.
7. PARTICIPANT DISCONTINUATION/WITHDRAWAL FROM STUDY
7.1. Participant Discontinuation/Withdrawal From the Study
A participant may withdraw from the study at any time at his/her own request.  Reasons for 
discontinuation from the study include the following:

Refused further follow-up;

Lost to follow-up;

Death;

Study terminated by sponsor.
If a participant withdraws from the study, he/she may request destruction of any remaining 
samples taken and not tested, and the investigator must document any such requests in the 
site study records and notify the sponsor accordingly.
If the participant withdraws from the study and also withdraws consent for disclosure of 
future information (see Section 7.1.1), no further evaluations should be performed and no 
additional data should be collected.  The sponsor may retain and continue to use any data 
collected before such withdrawal of consent.
7.1.1. Withdrawal of Consent
Participants should notify the investigator in writing of the decision to withdraw consent for
future follow-up, whenever possible.  The withdrawal of consent should be explained in 
detail in the medical records by the investigator, as to whether the withdrawal was from study 
procedures and/or study follow-up, and this information should be entered on the appropriate 
CRF page.  In the event that vital status (whether the participant is alive or dead) is being 
measured, publicly available information should be used to determine vital status only in a 
manner that is in accordance with local law.
7.2. Lost to Follow-up
A participant will be considered lost to follow-up if he or she repeatedly fails to return for 
scheduled visits and is unable to be contacted by the study site.
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The following actions must be taken if a participant fails to return to the clinic for/attend a 
protocol-required study visit:

The site must attempt to contact the participant and reschedule the missed visit as 
soon as possible and ascertain whether or not the participant wishes to and/or should 
continue in the study;

Before a participant is deemed lost to follow-up, the investigator or designee must 
make every effort to regain contact with the participant (where possible, 3 telephone 
calls and, if necessary, a certified letter to the participant’s last known mailing 
address or local equivalent methods). These contact attempts should be documented 
in the participant’s medical record;

Should the participant continue to be unreachable, he/she will be considered to have 
withdrawn from the study.
8. STUDY ASSESSMENTS AND PROCEDURES
The investigator (or an appropriate delegate at the investigator site) must obtain a signed and 
dated ICD and assent, as appropriate (Section 10.1.3), before performing any protocol-
required procedure, in accordance with the site’s remote consenting process and guidelines.
Study procedures will be conducted by the home health care vendor at the participant’s 
home, and/or by the investigator via remote communication. Results of any assessments 
performed by the home health care vendor will be documented by the home health care 
vendor personnel, (electronically) transferred to the central site, reviewed by the PI or his/her 
designee, and transcribed to a CRF by study site personnel.
Protocol-required study procedures and their timing are summarized in the SoA. Protocol
waivers or exemptions are not allowed. Adherence to the study design requirements, 
including those specified in the SoA, is essential and required for study conduct.
Safety issues related to protocol-required procedures should be discussed with the sponsor 
immediately upon occurrence or awareness to determine whether the participant should 
continue or discontinue from the study.
All screening evaluations must be completed and reviewed to confirm that potential 
participants meet all eligibility criteria. The investigator will maintain a screening log to 
record details of all participants screened and to confirm eligibility or record reasons for
screening failure, as applicable.
Every effort should be made to ensure that protocol-required tests and procedures (study 
interventions) are completed as described.  However, it is anticipated that there may be 
circumstances outside the control of the investigator that may make it infeasible to perform 
the test.  In these cases, the investigator must take all steps necessary to ensure the safety and 
well-being of the participant.  When a protocol-required test cannot be performed, the 
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investigator will document the reason for the missed test and any corrective and preventive 
actions that he or she has taken to ensure that required processes are adhered to as soon as 
possible.  The study team must be informed of these incidents in a timely manner.
The total blood sampling volume for individual participants in this study is approximately 
18 mL.  For participants who weigh <20 kg, the expected blood volume is approximately 
8 mL.
For samples being collected and shipped, detailed collection, processing, storage, and 
shipment instructions and contact information will be provided to the investigator site prior 
to initiation of the study.
8.1. Efficacy Assessments
Not applicable.
8.2. Safety Assessments
Planned time points and description for all safety assessments (AE collection) are provided in 
the SoA.  Unscheduled clinical laboratory measurements or other safety assessments may be 
obtained at any time during the study to assess any perceived safety issues.
8.2.1. Weight Measurement
Weight will be measured with a standardized, digital scale placed on a stable, flat surface. 
Participants must remove shoes, bulky layers of clothing, and jackets so that only light 
clothing remains.  They must also remove the contents of their pockets. Participants should 
be instructed to step gently onto the scale, place both feet together in the center of the scale 
and stand straight with eyes directed ahead.  Participants should be instructed to stand still 
and not sway.  Measurement will be recorded after the weight has stabilized.  Body weight 
should be reported with precision to one decimal place (eg, 0.1 kg).
8.2.2. Protocol-Required Clinical Safety Laboratory Assessments
Protocol-required clinical safety laboratory assessments will not be performed in this study.
8.2.3. Baseline Characteristics 
Demographic information such as year of birth (for the patients of the interventional studies 
and C3391007 participants), race, ethnicity, gender, and relationship to the interventional
study patient will be collected in compliance with local regulations.
At Screening, the average number of hours per week that the participant is in the same room 
as the interventional study patient will be collected. At Visit 2, the best estimate of number of 
days of contact (in same room) as the interventional study patient during the first two weeks 
after administration of IP will be collected.
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8.3. Adverse Events and Serious Adverse Events
The definitions of an AE, SAE, and Research Related Injury (RRI) can be found in 
Appendix 2. The investigator is required to assess whether any AE may be related to 
participation in the study.  All AEs (ie, serious and non-serious, including those attributed to 
a protocol-required procedure identified as RRI) are collected in the clinical study database. 
AEs may arise from symptoms or other complaints reported to the Investigator by the 
participant (or, when appropriate, by a caregiver, surrogate, or the participant's legally 
authorized representative) or they may arise from clinical findings of the Investigator or other 
HCPs (clinical signs, test results, etc.).
The investigator and any qualified designees are responsible for detecting, documenting, and 
recording events that meet the definition of an AE or SAE and remain responsible to pursue 
and obtain adequate information both to determine the outcome and to assess whether the 
event meets the criteria for classification as an SAE or caused the participant to discontinue 
the study intervention (see Section 6.1).
During the active collection period for safety events (see Section 8.3.1), each participant or 
parent/legal guardian/legally authorized representative will be questioned about the 
occurrence of AEs in a nonleading manner.
In addition, the investigator may be requested by Pfizer Safety to obtain specific follow-up 
information in an expedited fashion.
8.3.1. Time Period and Frequency for Collecting AE and SAE Information
The time period for actively eliciting and collecting AEs and SAEs (“active collection 
period”) for each participant begins at the time that the blood collection is performed at 
Visits 1, 3, and 4, and ends 2 hours after that procedure/intervention has completed.
The investigator is required to perform appropriate follow-up of each adverse event 
throughout and after the active collection period and until the AE/SAE or its sequelae resolve 
or stabilize at a level acceptable to the investigator and Pfizer concurs with that assessment.
If the participant withdraws from the study and also withdraws consent for the collection of 
future information, the active collection period ends when consent is withdrawn.
If a participant definitively discontinues or temporarily discontinues study intervention 
because of an AE or SAE, the AE or SAE must be recorded on the CRF and the SAE 
reported using the NIS AE Report form.
Since there is no product under study, there is no post-study active reporting period for the 
SAEs to be communicated to Pfizer Safety.
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8.3.1.1. Reporting SAEs to Pfizer Safety
All SAEs occurring in a participant during the active collection period (see Section 8.3.1) are 
reported to Pfizer Safety on the NIS AE Report form immediately upon awareness, as 
indicated in Appendix 2; under no circumstance should the time between awareness and 
reporting of the SAE exceed 24 hours. The investigator will also submit any updated SAE 
data to the sponsor within 24 hours of it being available.
Reportable SAEs include events related to an approved, Pfizer product taken by the 
participant under routine care, during the time they are participating in the study, should such 
events come to the attention of the Investigator (including an overdose or a medication error 
that led to the SAE). Refer to Appendix 2 for the definition of an overdose or medication 
error.
8.3.1.2. Recording Nonserious AEs and SAEs on the CRF
All applicable SAEs and nonserious AEs, as described in Appendix 2, that are directly 
observed and/or spontaneously reported by the participant during the active collection period 
(described in Section 8.3.1) will be recorded on the AE page of the CRF.
8.3.2. Method of Detecting AEs and SAEs
The method of recording, evaluating, and assessing causality of AEs and SAEs and the 
procedures for completing and transmitting SAE reports are provided in Appendix 2.
Care will be taken not to introduce bias when detecting AEs and/or SAEs.  Open-ended and 
nonleading verbal questioning of the participant is the preferred method to inquire about 
AE occurrences.
8.3.3. Follow-up of AEs and SAEs
After the initial AE/SAE report, the investigator is required to proactively follow each 
participant at subsequent visits/contacts. For each event, the investigator must pursue and 
obtain adequate information until resolution, stabilization, the event is otherwise explained, 
or the participant is lost to follow-up (as defined in Section 7.2).
In general, follow-up information will include a description of the event in sufficient detail to 
allow for a complete medical assessment of the case and independent determination of 
possible causality.  Any information relevant to the event, such as concomitant medications 
and illnesses, must be provided.  In the case of a participant death, a summary of available 
autopsy findings must be submitted as soon as possible to Pfizer Safety.
Further information on follow-up procedures is given in Appendix 2.
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8.3.4. 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 towards the safety of participants and the safety of a 
study intervention 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 a study intervention under clinical investigation.  The 
sponsor will comply with country-specific regulatory requirements relating to safety 
reporting to the regulatory authority, IRBs/ECs, and investigators.
8.3.5. Exposure During Pregnancy or Breastfeeding, and Environmental Exposure
The requirements for reporting pregnancy or breastfeeding and environmental exposure
apply throughout the entire active collection period and are outlined below; when such 
reports are required per protocol, the report must be transmitted to Pfizer Safety within 
24 hours of investigator awareness.
8.3.5.1. Exposure During Pregnancy
An EDP occurs if: 

A female participant is found to be pregnant while taking any Pfizer product under 
routine care, at any time during the study period (eg, a concomitant medication that is 
not required by the study protocol); or,

A male participant uses any Pfizer product under routine care during the study period 
(ie, a concomitant medication that is not required by the study protocol) and his 
partner subsequently becomes pregnant; or,

A female participant is found to be pregnant and is a household contact of a person 
who received a Pfizer gene therapy (such as fordadistrogene movaparvovec) within 2
months prior to or during pregnancy.
The investigator must report the EDP to Pfizer Safety within 24 hours of the investigator’s 
awareness, whether or not an SAE has occurred.

The initial information submitted should include the anticipated delivery date of the 
baby (see below for information related to termination of pregnancy).

An EDP report is not required if the Pfizer product taken under routine care is 
specifically approved for use in pregnant women (eg, vitamins) and is administered in 
accord with authorized use. However, if the infant experiences an SAE associated 
with such a drug, the SAE must be reported along with the EDP.

The Investigator must report the EDP to Pfizer Safety on the NIS AE Report Form 
and the EDP Supplemental Form. Relevant details of the exposure and the pregnancy 
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will be collected from the time informed consent was provided until final study 
follow-up.  If there is an SAE associated with the EDP, then the SAE is reported to 
Pfizer Safety using the NIS AE Report Form.
Follow-up must be conducted to obtain general information on the pregnancy and its 
outcome for all EDP reports.  The investigator will follow the pregnancy until completion (or 
until pregnancy termination) and notify Pfizer Safety of the outcome as a follow-up to the 
initial EDP Supplemental Form.  For a live birth, information regarding the structural 
integrity of the neonate at the time of birth should be provided.  In the event of a termination, 
the reason(s) for termination should be provided and information regarding the structural 
integrity of the terminated fetus should be included in the report (if available; not required if 
pre-procedure test findings were conclusive for a congenital anomaly and those findings are 
provided in the report).
Abnormal pregnancy outcomes are considered SAEs.  If the outcome of the pregnancy meets 
the criteria for an SAE (ie, ectopic pregnancy, spontaneous abortion, intrauterine fetal 
demise, neonatal death, or congenital anomaly), then the investigator should follow the 
procedures for reporting SAEs.
Additional pregnancy outcomes that must be reported to Pfizer Safety as SAEs include:

Spontaneous abortion including miscarriage and missed abortion;

Neonatal deaths that occur within 1 month of birth should be reported, without regard
to causality, as SAEs.  In addition, infant deaths after 1 month should be reported as 
SAEs when the investigator assesses the infant death may be related to exposure to 
the Pfizer product used under routine care during the study.
Additional information regarding the EDP may be requested by the sponsor.  Further 
follow-up of birth outcomes will be handled on a case-by-case basis (eg, follow-up on 
preterm infants may be requested to identify developmental delays).  In the case of paternal 
exposure, the investigator will provide the participant with the Pregnant Partner Release of 
Information Form to deliver to his partner.  The investigator must document in the source 
documents that the participant was given the Pregnant Partner Release of Information Form.
8.3.5.2. Exposure During Breastfeeding

An EDB occurs if female participant is found to be breastfeeding while taking any 
Pfizer product under routine care, at any time during the study period (eg, a 
concomitant medication that is not required by the study protocol).

A female participant is found to be breastfeeding while being a household contact of a 
person who received a Pfizer gene therapy (such as fordadistrogene movaparvovec).
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
An EDB report is not required when a Pfizer product specifically approved for use in 
breastfeeding women (eg, vitamins) is administered in accord with authorized use.  
However, if the infant experiences an SAE associated with such a drug, the SAE must 
be reported along with the EDB.
The investigator must report an EDB to Pfizer Safety within 24 hours of the investigator’s 
awareness, whether or not an SAE has occurred.

The investigator must report EDB to Pfizer Safety using the NIS AE Report form. 

If the EDB is associated with a SAE, then the SAE must be reported using the same 
NIS AE Report form.
8.3.5.3. Environmental Exposure
Not applicable. Environmental or occupational exposure is not reportable in this study since 
there is no Pfizer product under study.
8.3.6. Cardiovascular and Death Events
Not applicable.
8.3.7. Disease-Related Events and/or Disease-Related Outcomes Not Qualifying as AEs 
or SAEs
Not applicable.
8.3.8. Adverse Events of Special Interest
Not applicable.
8.3.8.1. Lack of Efficacy
In this study, lack of efficacy is reportable to Pfizer Safety for an approved Pfizer product 
used by the participant under routine care, if the Investigator is made aware.
Lack of efficacy is the failure of expected pharmacologic action or therapeutic benefit. Lack 
of efficacy should be reported as an SAE to Pfizer Safety if the lack of efficacy involves a 
vaccine, a contraceptive or a product that is used in the treatment of life-threatening diseases 
or conditions (eg, anti-infectives) (excluding HIV and cancer).
For Pfizer products that are not covered in paragraph above, lack of efficacy is reportable to 
Pfizer Safety only if associated with an SAE.
8.3.9. Medical Device Deficiencies
Not applicable.
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8.4. Treatment of Overdose
Not applicable.
8.5. Pharmacokinetics
Pharmacokinetic parameters are not evaluated in this study.
8.6. Pharmacodynamics
Pharmacodynamic parameters are not evaluated in this study.
8.7. Genetics
Not applicable.
8.8. Biomarkers
8.8.1. Banked Biospecimens
Biobank specimens will only be drawn in participants who weigh >20 kg.
Banked Biospecimens in this study are:

10 mL whole blood Prep B2 sample(s) optimized for serum.

Banked Biospecimens will be collected as local regulations and IRB/ECs allow.

Banked Biospecimens may be used for research related to fordadistrogene 
movaparvovec and DMD.

The samples may be analyzed as part of a multistudy assessment of analytes or 
biomarkers involved in immunity and/or immune response to fordadistrogene 
movaparvovec or other gene therapies.

The sponsor will store the Banked Biospecimens in a secure storage space with adequate 
measures to protect confidentiality.  Banked Biospecimens will be labeled with a code.  
The key between the code and the participant’s personally identifying information
(eg, name, address) will be held at the study site and will not be provided to the sample 
bank.

Samples for banking will be stored indefinitely or for another period as per local 
requirements.

Details on processes for collection and shipment of these samples can be found in the 
central laboratory manual.
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8.9. Immunogenicity Assessments
8.9.1. Blood Samples for Immunogenicity and Vector DNA Measurement
Blood samples will be collected for analysis of NAb to AAV9 and ADA to AAV9 titers.  
Blood samples will also be collected for qPCR analysis of fordadistrogene movaparvovec
vector DNA.
Detailed collection, processing, storage, and shipment instructions will be provided in the 
central laboratory manual.
Samples will be analyzed using validated analytical methods in compliance with Pfizer 
SOPs.
Lab results will be electronically transferred from the central lab to the Sponsor's database.
8.10. Health Economics
Health economics/medical resource utilization and health economics parameters are not 
evaluated in this study.
9. STATISTICAL CONSIDERATIONS
9.1. Statistical Hypotheses
There are no hypotheses to be tested. 
9.2. Sample Size Determination
Approximately 50 to 250 participants will be enrolled. Table 1 below shows the expected
precision, defined as the upper and lower 95% confidence limits, of the estimate of the 
proportion of participants who are negative for NAb to AAV9 at Baseline and who develop 
NAb to AAV9 post-Baseline for various numbers of enrolled participants. These 
calculations assume that 75% of the participants will be seronegative for NAb to AAV9 at 
Baseline.
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Table 1.
95% CI of the Estimate of the Proportion of Participants who are NAb 
Seronegative to AAV9 at Baseline and who Seroconvert to AAV9 
Post-Baseline
Interventional study patient who received
fordadistrogene movaparvovec
Interventional study patient who received
placebo
Total 
Enrolled 
in 
C3391007
Na
Number 
NAb 
seronegative 
to AAV9 at 
Baselineb
Percent who 
seroconvert 
to AAV9
95%, CIc
Na
Number 
NAb 
seronegative 
to AAV9 at 
Baselineb
Percent who 
seroconvert 
to AAV9
95%, CIc
50
33
25
1% 
(0, 4.9)
17
13
1% 
(0, 6.4)
5% 
(0, 13.5)
10% 
(0, 21.8)
25% 
(8.0, 42.0)
50% 
(30.4, 69.6)
100
66
50
1% 
(0, 3.8)
34
26
1% 
(0, 4.8)
5% 
(0, 11.0)
10% 
(1.7, 18.3)
25% 
(13.0, 37.0)
50% 
(36.1, 63.9)
150
100
75
1% 
(0, 3.3)
50
38
1% 
(0, 4.2)
5% 
(0.1, 9.9)
10% 
(3.2, 16.8)
25% 
(15.2, 34.8)
50% 
(38.7, 61.3)
200
133
100
1% 
(0, 3.0)
67
50
1%
(0, 3.8)
5% 
(0.7, 9.3)
10% 
(4.1, 15.9)
25% 
(16.5, 33.5)
50% 
(40.2, 59.8)
250
167
125
1% 
(0, 2.7)
83
62
1%
(0, 3.5)
5% 
(1.2, 8.8)
10% 
(4.7, 15.3)
25% 
(17.4, 32.6)
50% 
(41.2, 58.8)
a. Assumes, on average two thirds of patients are treated with fordadistrogene movaparvovec and one third are treated 
with placebo across the interventional studies.
b. Assumes 75%, are NAb seronegative at Baseline.
c. Assumes all participants within households and between households are independent.
9.3. Data Management
A Pfizer database will be used, and Pfizer will be responsible for the data management of this 
study, including quality checking of the data.  Details are included in the Data Management 
Plan.
9.4. Case Report Forms/Data Collection Tools/Electronic Data Record
As used in this protocol, the term CRF should be understood to refer to either a paper form or 
an electronic data record or both, depending on the data collection method used in this study.
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A CRF is required and should be completed for each included participant.  The completed 
original CRFs are the sole property of Pfizer and should not be made available in any form to 
third parties, except for authorized representatives of Pfizer or appropriate regulatory 
authorities, without written permission from Pfizer.  The investigator shall ensure that the 
CRFs are securely stored at the study site in encrypted electronic and/or paper form and will 
be password protected or secured in a locked room to prevent access by unauthorized third 
parties.
The investigator has ultimate responsibility for the collection and reporting of all clinical, 
safety, and laboratory data entered on the CRFs and any other data collection forms (source 
documents) and ensuring that they are accurate, authentic/original, attributable, complete, 
consistent, legible, timely (contemporaneous), enduring, and available when required.  The 
CRFs must be signed by the investigator or by an authorized staff member to attest that the 
data contained on the CRFs are true.  Any corrections to entries made in the CRFs or source 
documents must be dated, initialed, and explained (if necessary) and should not obscure the 
original entry.
The source documents will be collected by both the Home Health Care provider and the
Investigator site; data collected on the CRFs must match the source documents.
In some cases, the CRF may also serve as the source document.  In these cases, a document 
should be available at the investigator site and at Pfizer that clearly identifies those data that 
will be recorded on the CRF, and for which the CRF will stand as the source document.
9.5. Data Analysis
Detailed methodology for summary and statistical analyses of data collected in this study will 
be documented in the SAP, which will be dated, filed, and maintained by the sponsor.  The 
SAP may modify the plans outlined in the protocol; any major modifications of primary 
endpoint definitions or their analyses would be reflected in a protocol amendment.
For the primary, secondary, and each of the exploratory endpoints listed in Section 3, the 
proportion (and 95% CI) of C3391007 participants will be estimated for 2 groups of 
participants:

fordadistrogene movaparvovec: household contacts of patients in interventional 
studies C3391002, C3391003, C3391001, and C3391008 

placebo: household contacts of patients in interventional studies C3391002 and 
C3391003 
using generalized estimating equations methods with study as covariate to account for 
correlated responses within the same household. A binomial distribution with a log link and 
an exchangeable correlation matrix within each household (ie, between any two members of 
a household the correlation is the same) will be used.  Proportions and 95% confidence 
intervals will be provided separately for each visit (except for Detectable fordadistrogene 
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movaparvovec vector DNA in participants who seroconvert via either ADAs or NAbs) and 
overall at any time during the study.
Incidence of AEs will be summarized/listed.
Pharmacogenomic or biomarker data from banked biospecimens will be collected pursuant to 
local regulations/IRB during or after the trial and retained for future analyses; the results of 
such analyses are not planned to be included in the CSR.
9.6. Interim Analyses
To enable potentially informing participants and investigators of the estimated 
seroconversion rate as soon as possible, an independent, external team of statistician(s) and 
programmer(s) will be established to estimate the seroconversion rates. Only summary 
seroconversion rates will be communicated. 
Full reporting of C3391007 will occur when C3391003 and C3391002 have completed the
primary analysis; however, the sponsor may analyze the data during the course of the study 
(eg, for the purpose of regulatory submissions, safety reporting). Section 6.2 includes 
information for protecting the blind of the interventional studies.
The detailed blinding plan and data dissemination plan will be provided in conjunction with 
the Statistical Analysis Plan
9.7. Data Monitoring Committee or Other Independent Oversight Committee
This study will not use a Data Monitoring Committee.
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10. SUPPORTING DOCUMENTATION AND OPERATIONAL CONSIDERATIONS
10.1. Appendix 1: Regulatory, Ethical, and Study Oversight Considerations
10.1.1. Regulatory and Ethical Considerations
This study will be conducted in accordance with the protocol and with the following:

Consensus ethical principles derived from international guidelines including the 
Declaration of Helsinki and CIOMS International Ethical Guidelines;

Applicable ICH GCP guidelines;

Applicable laws and regulations, including applicable privacy laws.
The protocol, protocol amendments, ICD, SRSD(s), and other relevant documents
(eg, advertisements) must be reviewed and approved by the sponsor and submitted to an 
IRB/EC by the investigator and reviewed and approved by the IRB/EC before the study is 
initiated.
Any amendments to the protocol will require IRB/EC approval before implementation of 
changes made to the study design, except for changes necessary to eliminate an immediate 
hazard to study participants.
The investigator will be responsible for the following:

Providing written summaries of the status of the study to the IRB/EC annually or 
more frequently in accordance with the requirements, policies, and procedures 
established by the IRB/EC;

Notifying the IRB/EC of SAEs or other significant safety findings as required by 
IRB/EC procedures;

Providing oversight of the conduct of the study at the site and adherence to 
requirements of 21 CFR, ICH guidelines, the IRB/EC, European regulation 536/2014 
for clinical studies (if applicable), and all other applicable local regulations.
10.1.1.1. Reporting of Safety Issues and Serious Breaches of the Protocol or ICH GCP
In the event of any prohibition or restriction imposed (ie, clinical hold) by an applicable 
regulatory authority in any area of the world, or if the investigator is aware of any new 
information that might influence the evaluation of the benefits and risks of the study 
intervention, Pfizer should be informed immediately.
In addition, the investigator will inform Pfizer immediately of any urgent safety measures 
taken by the investigator to protect the study participants against any immediate hazard, and 
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of any serious breaches of this protocol or of ICH GCP that the investigator becomes aware 
of.
10.1.2. Responsible Parties
Contact details and the list of all responsible parties (PI names and site contact information) 
will be stored in the Pfizer Registry System and will be available upon request.
10.1.3. Informed Consent Process
The investigator or his/her representative will explain the nature of the study to the 
participant or his/her legally authorized representative and answer all questions regarding the 
study.  The participant or his/her legally authorized representative should be given sufficient 
time and opportunity to ask questions and to decide whether or not to participate in the trial.
Participants must be informed that their participation is voluntary. Participants or their 
legally authorized representative will be required to sign a statement of informed consent that 
meets the requirements of 21 CFR 50, local regulations, ICH guidelines, HIPAA 
requirements, where applicable, and the IRB/EC or study center. The participant may also be 
required to provide assent in compliance with local regulations and institutional review board 
(IRB) requirements.
The investigator must ensure that each study participant or his or her legally authorized 
representative is fully informed about the nature and objectives of the study, the sharing of 
data related to the study, and possible risks associated with participation, including the risks 
associated with the processing of the participant’s personal data.
The participant must be informed that his/her personal study-related data will be used by the 
sponsor in accordance with local data protection law. The level of disclosure must also be 
explained to the participant.
The participant must be informed that his/her medical records may be examined by Clinical 
Quality Assurance auditors or other authorized personnel appointed by the sponsor, by 
appropriate IRB/EC members, and by inspectors from regulatory authorities.
The investigator further must ensure that each study participant or his or her legally 
authorized representative is fully informed about his or her right to access and correct his or 
her personal data and to withdraw consent for the processing of his or her personal data.
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 ICD.
Participants must be reconsented to the most current version of the ICD(s) during their 
participation in the study.
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A copy of the ICD(s) must be provided to the participant or the participant’s legally 
authorized representative.
A participant who is rescreened is not required to sign another ICD if the rescreening occurs 
within 1 year from the previous ICD signature date.
Unless prohibited by local requirements or IRB/EC decision, the ICD will contain a separate 
section that addresses the use of samples for optional additional research. The optional 
additional research does not require the collection of any further samples.  The investigator 
or authorized designee will explain to each participant the objectives of the additional
research. Participants will be told that they are free to refuse to participate and may 
withdraw their consent at any time and for any reason during the storage period. A separate 
signature will be required to document a participant's agreement to allow specimens to be 
used for additional research. Participants who decline to participate in this optional 
additional research will not provide this separate signature.
10.1.4. Data Protection
All parties will comply with all applicable laws, including laws regarding the implementation 
of organizational and technical measures to ensure protection of participant data.
Participants’ personal data will be stored at the study site in encrypted electronic and/or paper 
form and will be password protected or secured in a locked room to ensure that only 
authorized study staff have access.  The study site will implement appropriate technical and 
organizational measures to ensure that the personal data can be recovered in the event of 
disaster.  In the event of a potential personal data breach, the study site will be responsible 
for determining whether a personal data breach has in fact occurred and, if so, providing 
breach notifications as required by law.
To protect the rights and freedoms of participants with regard to the processing of personal 
data, participants will be assigned a single, participant-specific numerical code. Any 
participant records or data sets that are transferred to the sponsor will contain the numerical 
code; participant names will not be transferred. All other identifiable data transferred to the 
sponsor will be identified by this single, participant-specific code. The study site will 
maintain a confidential list of participants who participated in the study, linking each 
participant’s numerical code to his or her actual identity and medical record identification. In 
case of data transfer, the sponsor will protect the confidentiality of participants’ personal data 
consistent with the clinical study agreement and applicable privacy laws.
10.1.5. Dissemination of Clinical Study Data
Pfizer fulfills its commitment to publicly disclose clinical study results through posting the 
results of studies on www.clinicaltrials.gov (ClinicalTrials.gov), the EudraCT, and/or 
www.pfizer.com, and other public registries in accordance with applicable local 
laws/regulations.  In addition, Pfizer reports study results outside of the requirements of local 
laws/regulations pursuant to its SOPs.
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In all cases, study results are reported by Pfizer in an objective, accurate, balanced, and 
complete manner and are reported regardless of the outcome of the study or the country in 
which the study was conducted.
www.clinicaltrials.gov
Pfizer posts clinical trial results on www.clinicaltrials.gov for Pfizer-sponsored interventional 
studies (conducted in patients) that evaluate the safety and/or efficacy of a product, 
regardless of the geographical location in which the study is conducted.  These results are 
submitted for posting in accordance with the format and timelines set forth by US law.
EudraCT
Pfizer posts clinical trial results on EudraCT for Pfizer-sponsored interventional studies in 
accordance with the format and timelines set forth by EU requirements.
www.pfizer.com
Pfizer posts public disclosure synopses (CSR synopses in which any data that could be used 
to identify individual participants have been removed) on www.pfizer.com for 
Pfizer-sponsored interventional studies at the same time the corresponding study results are
posted to www.clinicaltrials.gov.
Documents within marketing authorization packages/submissions
Pfizer complies with the European Union Policy 0070, the proactive publication of clinical 
data to the EMA website.  Clinical data, under Phase 1 of this policy, includes clinical 
overviews, clinical summaries, CSRs, and appendices containing the protocol and protocol 
amendments, sample CRFs, and statistical methods.  Clinical data, under Phase 2 of this 
policy, includes the publishing of individual participant data.  Policy 0070 applies to new 
marketing authorization applications submitted via the centralized procedure since 
01 January 2015 and applications for line extensions and for new indications submitted via 
the centralized procedure since 01 July 2015.
Data Sharing
Pfizer provides researchers secure access to patient-level data or full CSRs for the purposes 
of “bona-fide scientific research” that contributes to the scientific understanding of the 
disease, target, or compound class. Pfizer will make available data from these trials 
24 months after study completion.  Patient-level data will be anonymized in accordance with 
applicable privacy laws and regulations.  CSRs will have personally identifiable information 
redacted.
Data requests are considered from qualified researchers with the appropriate competencies to 
perform the proposed analyses. Research teams must include a biostatistician. Data will not 
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be provided to applicants with significant conflicts of interest, including individuals 
requesting access for commercial/competitive or legal purposes.
10.1.6. Data Quality Assurance
All participant data relating to the study will be recorded on printed or electronic CRF unless 
transmitted to the sponsor or designee electronically (eg, laboratory data). The investigator is 
responsible for verifying that data entries are accurate and correct by physically or 
electronically signing the CRF.
The investigator must maintain accurate documentation (source data) that supports the 
information entered in the CRF.
The investigator must ensure that the CRFs are securely stored at the study site in encrypted 
electronic and/or paper form and are password protected or secured in a locked room to 
prevent access by unauthorized third parties.
The investigator must permit study-related monitoring, audits, IRB/EC review, and 
regulatory agency inspections and provide direct access to source data documents.  This 
verification may also occur after study completion.  It is important that the investigator(s) 
and their relevant personnel are available during the monitoring visits and possible audits or 
inspections and that sufficient time is devoted to the process.
Monitoring details describing strategy (eg, risk-based initiatives in operations and quality 
such as risk management and mitigation strategies and analytical risk-based monitoring), 
methods, responsibilities, and requirements, including handling of noncompliance issues and 
monitoring techniques (central, remote, or on-site monitoring), are provided in the 
monitoring plan.
The sponsor or designee is responsible for the data management of this study, including 
quality checking of the data.
Study monitors will perform ongoing source data verification to confirm that data entered 
into the CRF by authorized site personnel 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.
Records and documents, including signed ICDs, pertaining to the conduct of this study must 
be retained by the investigator for 15 years after study completion unless local regulations or 
institutional policies require a longer retention period. No records may be destroyed during 
the retention period without the written approval of the sponsor. No records may be 
transferred to another location or party without written notification to the sponsor. The 
investigator must ensure that the records continue to be stored securely for as long as they are 
maintained.
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When participant data are to be deleted, the investigator will ensure that all copies of such 
data are promptly and irrevocably deleted from all systems.
The investigator(s) will notify the sponsor or its agents immediately of any regulatory 
inspection notification in relation to the study.  Furthermore, the investigator will cooperate 
with the sponsor or its agents to prepare the investigator site for the inspection and will allow 
the sponsor or its agent, whenever feasible, to be present during the inspection.  The 
investigator site and investigator will promptly resolve any discrepancies that are identified 
between the study data and the participant’s medical records.  The investigator will promptly 
provide copies of the inspection findings to the sponsor or its agent.  Before response 
submission to the regulatory authorities, the investigator will provide the sponsor or its 
agents with an opportunity to review and comment on responses to any such findings.
10.1.7. Source Documents
Source documents provide evidence for the existence of the participant and substantiate the 
integrity of the data collected. Source documents are filed at the investigator site.
Data reported on the CRF or entered in the eCRF that are from source documents must be 
consistent with the source documents or the discrepancies must be explained. The 
investigator may need to request previous medical records or transfer records, depending on 
the study. Also, the participant’s current medical record must be available.
Definition of what constitutes source data can be found in the Study Monitoring Plan.
Description of the use of computerized system is documented in the Data Management Plan.
10.1.8. Study and Site Start and Closure
The study site start date is the date on which the clinical study will be open for recruitment of 
participants study site.
The first act of recruitment is the date of the first study participant’s first visit and will be the 
study start date.
The sponsor or designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the sponsor. Study sites will be closed upon 
study completion. A study site is considered closed when all required documents and study 
supplies have been collected and a study-site closure visit has been performed.
The investigator may initiate study-site closure at any time upon notification to the sponsor 
or designee/CRO if requested to do so by the responsible IRB/EC or if such termination is 
required to protect the health of study participants.
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Reasons for the early closure of a study site by the sponsor may include but are not limited 
to:

Failure of the investigator to comply with the protocol, the requirements of the 
IRB/EC or local health authorities, the sponsor's procedures, or GCP guidelines;

Inadequate recruitment of participants by the investigator;

Discontinuation of further development.
If the study is prematurely terminated or suspended, the sponsor shall promptly inform the 
investigators, the ECs/IRBs, the regulatory authorities, and any CRO(s) used in the study of 
the reason for termination or suspension, as specified by the applicable regulatory 
requirements. The investigator shall promptly inform the participant and should assure 
appropriate participant therapy and/or follow-up.
Study termination is also provided for in the clinical study agreement.  If there is any conflict 
between the contract and this protocol, the contract will control as to termination rights.
10.1.9. Publications by Investigators
Pfizer supports the exercise of academic freedom and has no objection to publication by the 
PI of the results of the study based on information collected or generated by the PI, whether 
or not the results are favorable to the Pfizer product.  However, to ensure against inadvertent 
disclosure of confidential information or unprotected inventions, the investigator will provide 
Pfizer an opportunity to review any proposed publication or other type of disclosure of the 
results of the study (collectively, “publication”) before it is submitted or otherwise disclosed.
The investigator will provide any publication to Pfizer at least 30 days before it is submitted 
for publication or otherwise disclosed.  If any patent action is required to protect intellectual 
property rights, the investigator agrees to delay the disclosure for a period not to exceed an 
additional 60 days.
The investigator will, on request, remove any previously undisclosed confidential 
information before disclosure, except for any study- or Pfizer product-related information 
necessary to the appropriate scientific presentation or understanding of the study results.
If the study is part of a multicenter study, the investigator agrees that the first publication is 
to be a joint publication covering all investigator sites, and that any subsequent publications 
by the PI will reference that primary publication.  However, if a joint manuscript has not 
been submitted for publication within 12 months of completion or termination of the study at 
all participating sites, the investigator is free to publish separately, subject to the other 
requirements of this section.
For all publications relating to the study, the institution will comply with recognized ethical 
standards concerning publications and authorship, including Section II - “Ethical 
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Considerations in the Conduct and Reporting of Research” of the Uniform Requirements for 
Manuscripts Submitted to Biomedical Journals, http://www.icmje.org/index.html#authorship, 
established by the International Committee of Medical Journal Editors.
Publication of study results is also provided for in the CSA between Pfizer and the 
institution.  In this section entitled Publications by Investigators, the defined terms shall have 
the meanings given to them in the CSA.
If there is any conflict between the CSA and any attachments to it, the terms of the CSA 
control.  If there is any conflict between this protocol and the CSA, this protocol will control 
as to any issue regarding treatment of study participants, and the CSA will control as to all 
other issues.
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10.2. Appendix 2: Adverse Events: Definitions and Procedures for Recording, 
Evaluating, Follow-up, and Reporting
10.2.1. Definition of AE
AE Definition

An AE is any untoward medical occurrence in a patient or clinical study participant, 
temporally associated with a study intervention, whether or not considered related to 
the study intervention.

NOTE: An AE can therefore be any unfavorable and unintended sign (including an 
abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally 
associated with a study intervention.
Events Meeting the AE Definition

Any abnormal laboratory test results (hematology, clinical chemistry, or urinalysis) or 
other safety assessments (eg, ECG, radiological scans, vital sign measurements), 
including those that worsen from baseline, considered clinically significant in the 
medical and scientific judgment of the investigator. Any abnormal laboratory test 
results that meet any of the conditions below must be recorded as an AE:
o
Is associated with accompanying symptoms.
o
Requires additional diagnostic testing or medical/surgical intervention.
o
Leads to a change in the study intervention schedule (outside of any 
protocol-specified adjustments) or discontinuation from the study, 
significant additional concomitant drug treatment, or other therapy.
o
Exacerbation of a chronic or intermittent preexisting condition including 
either an increase in frequency and/or intensity of the condition.

New conditions detected or diagnosed after study intervention administration 
even though it may have been present before the start of the study.

Signs, symptoms, or the clinical sequelae of a suspected drug-drug interaction.

Signs, symptoms, or the clinical sequelae of a suspected overdose of a 
concomitant medication.  Overdose per se will not be reported as an AE/SAE 
unless it is an intentional overdose taken with possible suicidal/self-harming 
intent.  Such overdoses should be reported regardless of sequelae.
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Events NOT Meeting the AE Definition

Any clinically significant abnormal laboratory findings or other abnormal safety 
assessments which are associated with the underlying disease, unless judged by the 
investigator to be more severe than expected for the participant’s condition.

The disease/disorder being studied or expected progression, signs, or symptoms of the 
disease/disorder being studied, unless more severe than expected for the participant’s 
condition.

Medical or surgical procedure (eg, endoscopy, appendectomy): the condition that 
leads to the procedure is the AE.

Situations in which an untoward medical occurrence did not occur (social and/or 
convenience admission to a hospital).

Anticipated day-to-day fluctuations of preexisting disease(s) or condition(s) present 
or detected at the start of the study that do not worsen.
10.2.2. Definition of SAE
If an event is not an AE per definition above, then it cannot be an SAE even if serious 
conditions are met (eg, hospitalization for signs/symptoms of the disease under study, death 
due to progression of disease).
An SAE is defined as any untoward medical occurrence that, at any dose:
a. Results in death
b. Is life-threatening
The term “life-threatening” in the definition of “serious” refers to an event in which 
the participant was at risk of death at the time of the event.  It does not refer to an 
event that hypothetically might have caused death if it were more severe.
c.
Requires inpatient hospitalization or prolongation of existing hospitalization
In general, hospitalization signifies that the participant has been detained (usually 
involving at least an overnight stay) at the hospital or emergency ward for 
observation and/or treatment that would not have been appropriate in the physician’s 
office or outpatient setting.  Complications that occur during hospitalization are AEs.  
If a complication prolongs hospitalization or fulfills any other serious criteria, the 
event is serious.  When in doubt as to whether “hospitalization” occurred or was 
necessary, the AE should be considered serious.
Hospitalization for elective treatment of a preexisting condition that did not worsen 
from baseline is not considered an AE.
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d. Results in persistent disability/incapacity

The term disability means a substantial disruption of a person’s ability to conduct 
normal life functions.

This definition is not intended to include experiences of relatively minor medical 
significance such as uncomplicated headache, nausea, vomiting, diarrhea, 
influenza, and accidental trauma (eg, sprained ankle) which may interfere with or 
prevent everyday life functions but do not constitute a substantial disruption.
e.
Is a congenital anomaly/birth defect
f.
Other situations:

Medical or scientific judgment should be exercised in deciding whether SAE 
reporting is appropriate in other situations such as important medical events that 
may not be immediately life-threatening or result in death or hospitalization but 
may jeopardize the participant or may require medical or surgical intervention to 
prevent one of the other outcomes listed in the above definition.  These events 
should usually be considered serious.

Examples of such events include invasive or malignant cancers, intensive 
treatment in an emergency room or at home for allergic bronchospasm, blood 
dyscrasias or convulsions that do not result in hospitalization, or development of 
drug dependency or drug abuse.
g. Research Related Injury
Should a participant, in the investigator’s opinion, suffer a medically important 
research related injury caused by their participation in the study, the designated Pfizer 
clinician or medical monitor must be notified immediately by telephone or email.
A medically important research related injury is any untoward medical occurrence 
that:

Results in death;

Is life-threatening (immediate risk of death);

Requires inpatient hospitalization or prolongation of existing hospitalization;

Results in persistent or significant disability/incapacity (substantial disruption 
of the ability to conduct normal life functions);

Results in congenital anomaly/birth defect.
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Medical and scientific judgment is exercised in determining whether an injury is an 
important medical event. An important medical event may not be immediately 
life-threatening and/or result in death or hospitalization. However, if it is determined 
that the event may jeopardize the participant or may require intervention to prevent 
one of the other outcomes listed in the definition above, the important medical event 
should be reported as a research related injury.

An investigator may be requested by the designated Pfizer clinician or medical 
monitor to obtain specific additional follow-up information in an expedited 
fashion. In general, this will include a description of the injury in sufficient detail to 
allow for a complete medical assessment of the case and independent determination 
of possible causality. Information on other possible causes of the event, such as 
concomitant treatments, vaccines, and/or illnesses must be provided. In the case of a 
participant death, a summary of available autopsy findings must be submitted as soon 
as possible to Pfizer or its designated representative.

Definition of Medication Error (for an approved Pfizer product used by the 
participant under routine care if the Investigator is made aware):

A medication error is any unintentional error in the prescribing, dispensing, or 
administration of a medicinal product that may cause or lead to inappropriate 
medication use or patient harm while in the control of the healthcare professional, 
patient, or consumer. Such events may be related to:

professional practice,

procedures,

systems, including:
o
Prescribing
o
Order communication
o
Product labeling, packaging, and nomenclature
o
Dispensing
o
Distribution
o
Administration
o
Education
o
Monitoring
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o
Use

Medication errors include near-misses involving or not involving a patient directly or
confusion regarding invented names (eg, trade name, brand name).

Definition of Overdose

An overdose is an administration of a quantity of a medicinal product given per 
administration or cumulatively that is above the maximum recommended dose 
according to the authorized product information.
10.2.3. Recording/Reporting and Follow-up of AEs and/or SAEs
AE and SAE Recording/Reporting During the Active Collection Period
The table below summarizes the requirements for recording adverse events on the CRF and 
for reporting serious adverse events on the NIS AE Report form to Pfizer Safety throughout 
the active collection period(s).  These requirements are delineated for 3 types of events: 
(1) SAEs; (2) nonserious adverse events (AEs); and (3) exposure to a Pfizer product used 
under routine care during pregnancy or breastfeeding.
It should be noted that the NIS AE Report form for reporting of SAE information is not the 
same as the AE page of the CRF. Wherever the same data or information are to be collected, 
the forms must be completed in a consistent manner.  AEs should be recorded using concise 
medical terminology and, when referring to a specific event, the same AE term should be 
used on both the CRF and the NIS AE Report form.
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Safety Event
Record on the CRF
Report on the NIS AE Report 
Form to Pfizer Safety within 
24 hours of awareness
SAE
Any SAE that occurs 
during the active 
collection period(s).
Any SAE that occurs 
outside the active 
collection period(s) that 
the investigator suspects 
may be related to the
protocol-required 
procedure/intervention. 
Any SAE that the investigator 
suspects may be related to any 
Pfizer product used by the 
participant under routine care 
during and outside any active 
collection period. 
Non-serious AEs
Any non-serious AE that 
occurs during the active 
collection period(s). 
Any AE that occurs 
outside the active 
collection period(s) that 
the investigator suspects 
may be related to the 
protocol-required 
procedure/intervention.
None
Scenarios involving 
exposure during 
pregnancy (EDP) and 
exposure during breast 
feeding (EDB). 
Instances of EDP or EDB
are not captured in the 
CRF.
All instances of EDP (whether or 
not there is an associated SAE). *
All instances of EDB are reported 
(whether or not there is an 
associated AE/SAE). ** 
*EDP (with or without an associated AE or SAE): any pregnancy information is reported to Pfizer Safety using 
the NIS AE Report Form and the EDP Supplemental Form; if the EDP is associated with an SAE, then the 
SAE is reported to Pfizer Safety using the NIS AE Report Form.
**EDB is reported to Pfizer Safety using the NIS AE Report Form, which would also include details of any 
SAE that might be associated with the EDB.
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
When an AE/SAE occurs, it is the responsibility of the investigator to review all 
documentation (eg, hospital progress notes, laboratory reports, and diagnostic reports) 
related to the event.

The investigator will then record all relevant AE/SAE information in the CRF.

It is not acceptable for the investigator to send photocopies of the participant’s 
medical records to Pfizer Safety in lieu of completion of the NIS AE Report form or 
the Adverse Event CRF page.

There may be instances when copies of medical records for certain cases are 
requested by Pfizer Safety.  In this case, all participant identifiers, with the exception 
of the participant number, will be redacted on the copies of the medical records 
before submission to Pfizer Safety.

The investigator will attempt to establish a diagnosis of the event based on signs, 
symptoms, and/or other clinical information.  Whenever possible, the diagnosis (not 
the individual signs/symptoms) will be documented as the AE/SAE.
Assessment of Intensity
The investigator will make an assessment of intensity for each AE and SAE reported during 
the study and assign it to 1 of the following categories:

Mild: An event that is easily tolerated by the participant, causing minimal discomfort 
and not interfering with everyday activities.

Moderate: An event that causes sufficient discomfort and interferes with normal 
everyday activities.

Severe: An event that prevents normal everyday activities.  An AE that is assessed as 
severe should not be confused with an SAE.  Severe is a category utilized for rating 
the intensity of an event; and both AEs and SAEs can be assessed as severe.

An event is defined as “serious” when it meets at least 1 of the predefined outcomes 
as described in the definition of an SAE, NOT when it is rated as severe.
Assessment of Causality

The investigator is obligated to assess the relationship between any study intervention 
(or Pfizer product used under routine care) and each occurrence of each AE/SAE.
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
A “reasonable possibility” of a relationship conveys that there are facts, evidence, 
and/or arguments to suggest a causal relationship, rather than a relationship cannot be 
ruled out.

The investigator will use clinical judgment to determine the relationship.

Alternative causes, such as underlying disease(s), concomitant therapy, and other risk 
factors, as well as the temporal relationship of the event to study intervention 
administration, will be considered and investigated.

In making his/her assessment, the investigator will also consult the product 
information for a marketed Pfizer product used under routine care, if the Investigator 
is made aware.

For each AE/SAE, the investigator must document in the medical notes that he/she 
has reviewed the AE/SAE and has provided an assessment of causality.

There may be situations in which an SAE has occurred, and the investigator has 
minimal information to include in the initial report to the sponsor.  However, it is 
very important that the investigator always make an assessment of causality for 
every event before the initial transmission of the SAE data to the sponsor.

The investigator may change his/her opinion of causality in light of follow-up 
information and send an SAE follow-up report with the updated causality assessment.

The causality assessment is one of the criteria used when determining regulatory 
reporting requirements.

If the investigator does not know whether or not the study intervention caused the 
event, then the event will be handled as “related to study intervention” for reporting 
purposes, as defined by the sponsor.  In addition, if the investigator determines that an 
SAE is associated with study procedure/intervention, the investigator must record this 
causal relationship in the source documents and CRF, and report such an assessment 
in the NIS AE Report form and in accordance with the SAE reporting requirements.
Follow-up of AEs and SAEs

The investigator is obligated to perform or arrange for the conduct of supplemental 
measurements and/or evaluations as medically indicated or as requested by the 
sponsor to elucidate the nature and/or causality of the AE or SAE as fully as possible.  
This may include additional laboratory tests or investigations, histopathological 
examinations, or consultation with other healthcare providers.
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
If a participant dies during participation in the study or during a recognized follow-up 
period, the investigator will provide Pfizer Safety with a copy of any postmortem 
findings including histopathology.

New or updated information will be recorded in the originally completed CRF.

The investigator will submit any updated SAE data to the sponsor within 24 hours of 
receipt of the information.
10.2.4. Reporting of SAEs

SAE Reporting to Pfizer Safety via NIS AE Report Form

Facsimile transmission of the NIS AE Report form is the preferred method to transmit 
this information to Pfizer Safety.

In circumstances when the facsimile is not working, notification by telephone is 
acceptable with a copy of the NIS AE Report form sent by overnight mail or courier 
service.

Initial notification via telephone does not replace the need for the investigator to 
complete and sign the NIS AE Report form pages within the designated reporting 
time frames.
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10.3. Appendix 3: Liver Safety: Suggested Actions and Follow-up Assessments
Potential Cases of Drug-Induced Liver Injury (for an approved Pfizer product used by 
the participant under routine care, if the Investigator is made aware)
LFTs are not required as a routine safety monitoring procedure in this study.  However, 
should an investigator deem it necessary to assess LFTs because a participant presents with 
clinical signs/symptoms that the investigator suspects may be due to a Pfizer product used 
under routine care, then, such LFT results should be managed and followed as described 
below.
Humans exposed to a drug who show no sign of liver injury (as determined by elevations in 
transaminases) are termed “tolerators,” while those who show transient liver injury, but adapt 
are termed “adaptors.”  In some participants, transaminase elevations are a harbinger of a 
more serious potential outcome.  These participants fail to adapt and therefore are 
"susceptible" to progressive and serious liver injury, commonly referred to as DILI.  
Participants who experience a transaminase elevation above 3 × ULN should be monitored 
more frequently to determine if they are an “adaptor” or are “susceptible.”
In the majority of DILI cases, elevations in AST and/or ALT precede TBili elevations (>2 ×
ULN) by several days or weeks.  The increase in TBili typically occurs while AST/ALT 
is/are still elevated above 3 × ULN (ie, AST/ALT and TBili values will be elevated within 
the same laboratory sample).  In rare instances, by the time TBili elevations are detected, 
AST/ALT values might have decreased.  This occurrence is still regarded as a potential DILI.  
Therefore, abnormal elevations in either AST OR ALT in addition to TBili that meet the 
criteria outlined below are considered potential DILI (assessed per Hy’s law criteria) cases
and should always be considered important medical events, even before all other possible 
causes of liver injury have been excluded.
The threshold of laboratory abnormalities for a potential DILI case depends on the 
participant’s individual baseline values and underlying conditions.  Participants who present 
with the following laboratory abnormalities should be evaluated further as potential DILI 
(Hy’s law) cases to definitively determine the etiology of the abnormal laboratory values:

Participants with AST/ALT and TBili baseline values within the normal range who 
subsequently present with AST OR ALT values >3 × ULN AND a TBili value >2 × ULN 
with no evidence of hemolysis and an alkaline phosphatase value <2 × ULN or not 
available.
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
For participants with baseline AST OR ALT OR TBili values above the ULN, the 
following threshold values are used in the definition mentioned above, as needed, 
depending on which values are above the ULN at baseline:

Preexisting AST or ALT baseline values above the normal range: AST or ALT values 
>2 times the baseline values AND >3 × ULN; or >8 × ULN (whichever is smaller).
o
Preexisting values of TBili above the normal range: TBili level increased from 
baseline value by an amount of at least 1 × ULN or if the value reaches 
>3 × ULN (whichever is smaller).
Rises in AST/ALT and TBili separated by more than a few weeks should be assessed 
individually based on clinical judgment; any case where uncertainty remains as to whether it 
represents a potential Hy’s law case should be reviewed with the sponsor.
The participant should return to the investigator site and be evaluated as soon as possible, 
preferably within 48 hours from awareness of the abnormal results.  This evaluation should 
include laboratory tests, detailed history, and physical assessment.
In addition to repeating measurements of AST and ALT and TBili for suspected cases of 
Hy’s law, additional laboratory tests should include albumin, CK, direct and indirect 
bilirubin, GGT, PT/INR, total bile acids, and alkaline phosphatase.  Consideration should 
also be given to drawing a separate tube of clotted blood and an anticoagulated tube of blood 
for further testing, as needed, for further contemporaneous analyses at the time of the 
recognized initial abnormalities to determine etiology.  A detailed history, including relevant 
information, such as review of ethanol, acetaminophen/paracetamol (either by itself or as a 
coformulated product in prescription or over-the-counter medications), recreational drug, 
supplement (herbal) use and consumption, family history, sexual history, travel history, 
history of contact with a jaundiced person, surgery, blood transfusion, history of liver or 
allergic disease, and potential occupational exposure to chemicals, should be collected.  
Further testing for acute hepatitis A, B, C, D, and E infection and liver imaging (eg, biliary 
tract) and collection of serum samples for acetaminophen/paracetamol drug and/or protein 
adduct levels may be warranted.
All cases demonstrated on repeat testing as meeting the laboratory criteria of AST/ALT and 
TBili elevation defined above should be considered potential DILI (Hy’s law) cases if no 
other reason for the LFT abnormalities has yet been found.  Such potential DILI (Hy’s law) 
cases are to be reported as SAEs, irrespective of availability of all the results of the 
investigations performed to determine etiology of the LFT abnormalities.
A potential DILI (Hy’s law) case becomes a confirmed case only after all results of 
reasonable investigations have been received and have excluded an alternative etiology.
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10.4. Appendix 4: Abbreviations
The following is a list of abbreviations that may be used in the protocol.
Abbreviation
Term
AAV
adeno associated virus
AAV2
adeno associated virus serotype 2
AAV6
adeno associated virus serotype 6
AAV9
adeno associated virus serotype 9
ADA
anti-drug antibody
AE
adverse event
BLA
Biologics license application
CI
confidence interval
CRF
case report form
CRO
contract research organization
CSA
clinical study agreement
CSR
clinical study report
DCTs
data collection tools
DMD
Duchenne muscular dystrophy
DNA
deoxyribonucleic acid
EC
ethics committee
GCPs
Good Clinical Practices
GPP
Good Pharmacoepidemiology Practices
GRMD
Golden Retriever Muscular Dystrophy
IB
Investigator’s Brochure
ICD
Informed consent document
ICH
International Council for Harmonisation 
IEC
independent ethics committee
IP
investigational product
IRB
institutional review board
IV
intravenously
kg
kilogram
mL
milliliter
N/A
not applicable
NAb
neutralizing antibodies
PI
principal investigator
p.i. 
Post-infusion
qPCR
quantitative polymerase chain reaction
rAAV
Recombinant adeno associated virus
RRI
research related injury
SAE
serious adverse event
SAP
statistical analysis plan
SOA
schedule of activities
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Abbreviation
Term
SOP
standard operating procedure
SRSD
single reference safety document
US
United States
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Fordadistrogene movaparvovec (PF-06939926)
Protocol C3391007
Final Protocol, Amendment 1, 05 April 2022
PFIZER CONFIDENTIAL
CT45-GSOP-RF15A 1.0 Low-Interventional Study 1 (LIS1) Protocol Template 01-Dec-2020
Page 54 of 54
11. REFERENCES
1
Mah JK, Korngut L, Dykeman J, et al. A systematic review and meta-analysis on the 
epidemiology of Duchenne and Becker muscular dystrophy. Neuromuscul Disord.
2014;24(6):482-91.
2
Hoffman EP, Brown RH, Kunkel LM. Dystrophin: the protein product of the Duchenne 
muscular dystrophy locus. Cell. 1987;51(6):919-28.
3
Hendriksen RG, Hoogland G, Schipper S, et al. A possible role of dystrophin in 
neuronal excitability: a review of the current literature. Neurosci Biobehav Rev.
2015;51:255-62.
4
Boutin S, Monteilhet V, Veron P, et al. Human Gene Therapy. 2010;21:704-12.
5
Thwaite R, Pagès G, Chillón M et al. AAVrh.10 immunogenicity in mice and humans. 
Relevance of antibody cross-reactivity in human gene therapy. Gene Ther. 2015;22:196-
201.
6
Ellsworth J, O'Callaghan M, Rubin H, et al. Human Gene Therapy Clinical 
Development. 2018;29:60-67.
7
Luxturna [Package Insert]. Philadelphia, PA: Spark Therapeutics, Inc.; 2017. 
https://sparktx.com/LUXTURNA_US_Prescribing_Information.pdf.
8
Zolgensma [Package Insert]. Bannockburn, IL: AveXis, Inc.; 2019. 
https://www.avexis.com/content/pdf/prescribing_information.pdf.
9
Ferla R, Alliegro M, Marteau J-B, et al. Non-clinical Safety and Efficacy of an AAV2/8 
Vector Administered Intravenously for Treatment of Mucopolysaccharidosis Type VI. 
Mol Ther Methods Clin Dev. 2017;6:143-58.
10
Owens J, Moullier P, LeGuiner C. Translational Study in the GRMD Dog Model Using 
A Single Dose of A rAAV9 Vector Encoding A Human mini-Dystropin (rAAV9-hck-
opti-dys3978spA) after IV Administration. Product Translation to the GRMD Dog 
Model BAM-03. 2018;1-180.
090177e199ddb76b\Approved\Approved On: 05-Apr-2022 19:32 (GMT)

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090177e199ddb76b\Approved\Approved On: 05-Apr-2022 19:32 (GMT)
PPD