A Phase 1/2 Safety Study in Subjects With CHM (Choroideremia) Gene Mutations Using an Adeno-Associated Virus Serotype 2 Vector to Deliver the Normal Human CHM Gene [AAV2-hCHM] to the Retina
Phase: PHASE1
Conditions: Choroideremia, CHM (Choroideremia) Gene Mutations
Sponsor: Spark Therapeutics, Inc.



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SUMMARY OF CHANGES FROM PREVIOUS VERSION: 
 
SECTION: 
SUMMARY OF REVISIONS MADE: 
RATIONALE: 
Table of 
Clinical 
Assessments 
Years 6-15 of long-term follow up were 
removed from table, and the long term 
follow-up period concludes after year 5 
visit. 
Changes made per January 
2020 FDA guidance entitled 
Long Term Follow-Up After 
Administration of Human 
Gene Therapy Products. 
4.5: Long-
Term 
Follow-Up 
Removed years 6-15 of long term follow up 
phase per updated FDA guidance. 
Changes made per January 
2020 FDA guidance entitled 
Long Term Follow-Up After 
Administration of Human 
Gene Therapy Products. 
8.4: 
Definition 
of a SAE 
Added language clarifying that a 
prescheduled, elective procedure, or a 
routinely scheduled treatment that requires 
hospitalization is NOT considered to be an 
SAE. 
Updated language to match 
new protocol template 
8.8: 
Reporting 
Timeframes 
- Removed row that indicated a 5 business 
day requirement for a written report of other 
suspected adverse reactions that do not meet 
the definition of criteria. 
- Updated to match language in template 
Written report not required 
in these instances. 
9.4.2: Risk 
Assessment 
Updated to include risks seen to-date in the 
study. 
Updated to include risks 
seen to-date in the study. 
 
 

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Table of Contents ........................................................................................................................................ iii 
List of Figures and Tables ........................................................................................................................... iv 
Abbreviations and Definitions of Terms ...................................................................................................... v 
Protocol Synopsis ....................................................................................................................................... vii 
Schedule of Subject Evaluations & Study Design ..................................................................................... xvi 
1 
BACKGROUND INFORMATION AND RATIONALE .................................................................... 1 
1.1 
INTRODUCTION ................................................................................................................................. 1 
1.2 
NAME AND DESCRIPTION OF INVESTIGATIONAL PRODUCT .................................................................. 3 
1.3 
FINDINGS FROM NON-CLINICAL AND CLINICAL STUDIES ..................................................................... 5 
1.4 
NON-CLINICAL STUDIES OF AAV2-HCHM ...................................................................................... 10 
1.5 
SELECTION OF DRUGS AND DOSAGES ............................................................................................... 13 
2 
STUDY OBJECTIVES ...................................................................................................................... 13 
2.1 
PRIMARY OBJECTIVES ..................................................................................................................... 13 
2.2 
SECONDARY OBJECTIVES................................................................................................................. 13 
3 
INVESTIGATIONAL PLAN ............................................................................................................ 13 
3.1 
GENERAL SCHEMA OF STUDY DESIGN .............................................................................................. 13 
3.2 
ALLOCATION TO STUDY GROUPS ..................................................................................................... 15 
3.3 
STUDY DURATION, ENROLLMENT AND NUMBER OF SITES ................................................................. 16 
3.4 
STUDY POPULATION ........................................................................................................................ 16 
4 
STUDY PROCEDURES .................................................................................................................... 17 
4.1 
SCREENING/BASELINE VISIT ............................................................................................................ 18 
4.2 
STUDY INTERVENTION PHASE .......................................................................................................... 19 
4.3 
PRIOR AND CONCOMITANT MEDICATION .......................................................................................... 24 
4.4 
SUBJECT COMPLETION/WITHDRAWAL .............................................................................................. 24 
4.5 
LONG-TERM FOLLOW-UP ................................................................................................................ 25 
5 
STUDY EVALUATIONS AND MEASUREMENTS ........................................................................ 27 
5.1 
SCREENING/BASELINE AND MONITORING EVALUATIONS AND MEASUREMENTS ................................. 27 
5.2 
EFFICACY EVALUATIONS ................................................................................................................. 29 
5.3 
SAFETY EVALUATIONS .................................................................................................................... 30 
6 
STATISTICAL CONSIDERATIONS ............................................................................................... 31 
7 
INVESTIGATIONAL PRODUCT (INTERVENTION) ................................................................... 31 
7.1 
PACKAGING .................................................................................................................................... 31 
7.2 
LABELING ....................................................................................................................................... 32 
7.3 
DOSING ........................................................................................................................................... 32 
7.4 
STOPPING RULES ............................................................................................................................. 33 
7.5 
COMPLIANCE AND ADHERENCE ....................................................................................................... 33 
7.6 
ACCOUNTABILITY ........................................................................................................................... 33 
8 
SAFETY MANAGEMENT ............................................................................................................... 34 
8.1 
CLINICAL ADVERSE EVENTS ............................................................................................................ 34 
8.2 
ADVERSE EVENT REPORTING ........................................................................................................... 34 
8.3 
DEFINITION OF AN ADVERSE EVENT ................................................................................................. 35 
8.4 
DEFINITION OF A SERIOUS ADVERSE EVENT (SAE) ........................................................................... 35 
8.5 
GRADING OF ADVERSE EVENTS ....................................................................................................... 36 
8.6 
RELATIONSHIP TO THE INVESTIGATIONAL PRODUCT ......................................................................... 37 
8.7 
OTHER REPORTABLE EVENTS .......................................................................................................... 38 
8.8 
REPORTING TIMEFRAMES ................................................................................................................ 38 
8.9 
REPORTING OF PARTNER PREGNANCY OCCURENCES AND OUTCOMES ............................................... 39 
 

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9 
STUDY ADMINISTRATION ........................................................................................................... 40 
9.1 
DOSE GROUP ASSIGNMENT METHODS .............................................................................................. 40 
9.2 
DATA COLLECTION AND MANAGEMENT ........................................................................................... 40 
9.3 
SUBJECT CONFIDENTIALITY ............................................................................................................. 41 
9.4 
REGULATORY AND ETHICAL CONSIDERATIONS................................................................................. 41 
9.5 
RECRUITMENT STRATEGY................................................................................................................ 45 
9.6 
INFORMED CONSENT AND HIPAA AUTHORIZATION ......................................................................... 46 
9.7 
FINANCIAL CONSIDERATIONS OF STUDY PARTICIPATION .................................................................. 46 
10 
PUBLICATION ................................................................................................................................. 46 
11 
REFERENCES .................................................................................................................................. 48 
 
INVESTIGATOR’S STATEMENT........................................................................................................... 53 
 
 LIST OF FIGURES 
  
  
LIST OF TABLES 
Table 
Page  
Topic 
Table 5.1.3.1 
Page 28 
Summary of Clinical Laboratory Tests 
Table 5.1.3.2 
Page 28 
Summary of Research Laboratory Tests 
Table 5.1.3.3 
Page 29 
Summary of Ophthalmic Tests & Evaluations 
 
Figure 
Page  
Legend 
Figure 1    
 
Page 4       
Schematic of the AAV2-hCHM vector 
expression cassette 

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ABBREVIATIONS AND DEFINITIONS OF TERMS 
AAV 
Adeno-associated virus, a single-stranded DNA parvovirus. AAV has been 
engineered for use as a gene delivery vector 
AAV2-hCHM 
Adeno-associated virus vector, serotype 2, containing the normal human 
choroideremia gene, encoding the human REP-1 protein (Rab escort protein 
1) 
AAV2-hRPE65v2 
Adeno-associated virus vector, serotype 2, containing the human RPE65 
cDNA, used in a Phase 1 and follow-on clinical trials, as well as a Phase 3 
clinical trial from this Sponsor 
ACAID 
Anterior chamber-associated immune deviation 
AE 
Adverse event 
BLA 
Biologics License Application 
C 
Centigrade  
CβA 
Chicken beta actin, a promoter 
CBC 
Complete blood count 
CCMT 
Center for Cellular and Molecular Therapeutics (at CHOP) 
cDNA 
Complementary deoxyribonucleic acid 
CHM 
Choroideremia gene, which encodes Rab escort protein 1 (REP-1).  
CHM in this protocol denotes choroideremia, the disease. 
CHOP 
The Children’s Hospital of Philadelphia 
CLIA 
Clinical Laboratory Improvement Amendments 
CMV 
Cytomegalovirus 
CNS 
Central nervous system 
CRF 
Case Report Form 
CTA 
Clinical Trial Agreement 
CVC 
Clinical Vector Core (CCMT at CHOP) 
db 
Decibel 
dL 
Deciliter 
DLT 
Dose-limiting toxicity 
DNA 
Deoxyribonucleic acid 
DSMB 
Data Safety Monitoring Board 
ELISpot 
Enzyme-linked immunosorbent spot assay 
ERG 
Electroretinogram 
ETDRS 
Early Treatment of Diabetic Retinopathy Study (widely used visual acuity 
chart, first used to test visual acuity in a diabetic retinopathy study) 
FDA 
U.S. Food and Drug Administration  
g 
Gram 
GGTase 
Geranylgeranyltransferase 
GLP 
Good Laboratory Practice 
GMP 
Good Manufacturing Practice 
Hg 
Mercury 
HIPAA 
Health Insurance Portability and Accountability Act 
HIV 
Human immunodeficiency virus, causative virus of AIDS 
hRPE 
Human retinal pigment epithelium 
IBC 
Institutional Biosafety Committee 
ICH 
International Conference on Harmonisation 
IND 
Investigational New Drug  
IOP 
Intraocular pressure 

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IRA 
Independent Review Authority 
IRB/IEC 
Institutional Review Board/Independent Ethics Committee 
ITR 
Inverted Terminal Repeat 
IV 
Intravenous 
kDa 
Kilodalton 
L 
Liter 
LTFU 
Long-Term Follow-Up 
m 
Meter 
mg 
Milligram 
min 
Minute 
mL 
Milliliter 
mm 
Millimeter 
mm2 
Square millimeter 
mM 
Millimolar 
MOI 
Multiplicity of infection 
ms 
Milliseconds 
MTD 
Maximum tolerated dose 
ng 
Nanogram 
NHP 
Non-human primate 
NIH 
U.S. National Institutes of Health 
nm 
Nanometer 
OBA 
Office of Biological Activities (of NIH) 
OCT 
Optical coherence tomography (biomicroscopy) 
PBMC 
Peripheral blood mononuclear cells 
PCR 
Polymerase chain reaction 
QOL 
Quality of life, questionnaire 
rAAV 
Recombinant adeno-associated viral vectors  
RAC 
Recombinant DNA Advisory Committee (of the NIH, OBA) 
REP-1 
The choroideremia gene (CHM) encodes the Rab escort protein-1   (REP-
1), deficient in choroideremia, and important in intracellular vesicular 
transport  
RPE 
Retinal pigment epithelium 
RPE65 
Retinal pigment epithelium 65 kDa protein. In this protocol “RPE65” also 
refers to those clinical studies using the AAV2-hRPE65v2 vector for 
inherited retinal degeneration due to autosomal-recessive RPE65 gene 
mutations 
RPE65 
Retinal pigment epithelium 65 kDa protein gene 
RT-PCR 
Reverse transcriptase polymerase chain reaction 
SAE 
Serious adverse event 
SOP 
Standard operating procedure 
µL 
Microliter 
µM 
Micrometer 
vg 
Vector genomes (of AAV vector) 
WNL 
Within normal limits 

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Protocol Synopsis 
Study Title 
A Phase 1/2 Safety Study in Subjects with CHM (Choroideremia) 
Gene Mutations Using an Adeno-Associated Virus Serotype 2 
Vector to Deliver the Human CHM Gene [AAV2-hCHM] to the 
Retina 
 
Sponsor 
Spark Therapeutics, Inc. 
 
Clinical Phase 
Phase 1/2 
 
Study Rationale 
Gene delivery vectors based on Adeno-Associated Virus (AAV) 
have been in development for nearly three decades (Samulski et al., 
1982; Samulski et al., 1987). Numerous non-clinical research 
studies in mice, dogs and non-human primates have demonstrated 
safety and efficacy of AAV vectors encoding a variety of transgenes 
for a number of different conditions, as well as clinical studies 
encompassing a wide spectrum of diseases (Mingozzi and High, 
2011). Over the past several years, the first clinical trials in humans 
using AAV vectors for retinal disease have shown remarkable 
results, for both safety and clinical outcomes. Groundbreaking 
studies of AAV vectors by investigators at several institutions for 
inherited retinal degeneration due to autosomal-recessive mutations 
in the human retinal pigment epithelium 65 kDa protein gene 
(RPE65), have preliminarily demonstrated safety, tolerability, as 
well as efficacy for several endpoints initially in Phase 1 studies 
employing unilateral administration, and then in follow-on studies 
injecting the previously uninjected, contralateral eye (Maguire et al., 
2008; Bainbridge et al., 2008; Hauswirth et al.  2008; Maguire et 
al., 2009; Bennett et al., 2012). The twelve subjects entered to the 
Phase 1 clinical trial conducted under U.S. Food and Drug 
Administration (FDA) Investigational New Drug (IND) #13408 
generally showed improvement in light sensitivity and other visual 
parameters. While these early Phase 1 and follow-on studies of 
inherited retinal degeneration due to autosomal-recessive RPE65 
gene mutations have progressed to a Phase 3 clinical trial, leading to 
product approvals in the United States and Europe 
(LUXTURNATM), other retinal genetic diseases are being 
considered for gene transfer using AAV vectors encoding 
therapeutic proteins.  
Choroideremia is a degenerative retinal disease for which gene 
transfer research is in progress, including a clinical trial in the 
United Kingdom (MacLaren et al., 2014). This X-linked disease of 
males is characterized by deletions or mutations in the 

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choroideremia gene (CHM) at Xq21.2, resulting in defective or 
absent Rab escort protein-1 (REP-1), the encoded protein of the 
CHM gene (Nussbaum et al., 1985; Seabra et al., 1993; Seabra et 
al., 1995; Cremers et al., 1994; Alexandrov et al., 1994). Normally, 
Rab proteins are escorted by REP-1 to Rab 
geranylgeranyltransferase (Rab GGTase), which attaches 
geranylgeranyl groups to Rab proteins at the carboxy terminal ends 
(prenylation), an essential process that activates Rab proteins for 
their role in intracellular vesicular transport (Alexandrov et al., 
1994). In this way, REP-1 binds to newly synthesized Rab proteins, 
presents them to Rab GGTase, and delivers the geranylgeranylated 
Rab proteins to their target membranes. Absence or deficiency of 
REP-1 due to deletions or mutations in the CHM gene leads to 
cellular apoptosis and degeneration of the retinal pigment 
epithelium (RPE), choroid, and retinal photoreceptors. Although in 
normal retinas, the CHM gene is expressed in multiple cell types, 
including retinal pigment epithelium, photoreceptors and choroidal 
cells, there is evidence that the RPE cell is the primary disease-
causing cell type. This evidence stems from observations in 
conditional knockout mice (Tolmachova et al., 2006; Tolmachova 
et al., 2006) and also from studies evaluating efficacy of lentivirus-
mediated gene transfer (which targets RPE cells preferentially). The 
AAV serotype 2 vector, which targets RPE cells primarily (and 
other retinal cell types secondarily) is thus an ideal vector for 
choroideremia. Unlike lentivirus, AAV2 carries a very low risk of 
insertional mutagenesis. 
Clinically, choroideremia is diagnosed in affected males who 
manifest night blindness in childhood, followed by progressive 
constriction of visual fields, usually symptomatic in their teenage 
years, and eventual total blindness. The pathological hallmarks of 
the disease are degeneration of the choroicapillaris, as well as retinal 
pigment epithelium and photoreceptors (MacDonald et al., 2009). 
The disease course is variable, with early manifestations of 
decreased dark adaptation, progressing to decreased peripheral 
vision, followed eventually by loss of central vision, generally 
occurring later in life. In some patients, blindness occurs after a 
prolonged course. The rationale for a gene transfer approach for 
choroideremia is that a corrective gene delivered to the RPE early 
enough in the clinical course may halt degeneration and restore the 
RPE, retinal vasculature, and photoreceptors.  
This clinical study proposes to deliver the normal human CHM gene 
(hCHM) to the subretinal space using AAV2-hCHM, a single-
stranded AAV vector, based on several considerations. Previous 
clinical results from FDA Biologics License Application (BLA) 
application #125610 (IND #13408) demonstrated that following 

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subretinal administration of the AAV2-hRPE65v2 vector, 
stabilization or improvement of light sensitivity and visual endpoint 
measures occurred in each of the twelve participating subjects 
(Maguire et al., 2008; Maguire et al., 2009; Bennett et al., 2012). 
When tested in cell lines in vitro and in mice at doses similar to 
those used for AAV2-hRPE65v2, the AAV2-hCHM vector showed 
robust levels of transgene expression as judged by the number of 
cells transduced and the relative level of expression of the transgene 
as assessed by immunofluorescence, prenylation activity and 
restoration of Rab27 trafficking to the cellular membranes of 
induced pluripotent cells from affected patients (Vasireddy et al., 
2013). Non-clinical toxicity studies conducted in animals (mice, 
dogs, non-human primates) have demonstrated an acceptable safety 
profile for AAV2 serotype vectors (Acland et al., 2001; Acland et 
al., 2005; Bennicelli et al., 2008; Bennett et al., unpublished data), 
and bio-distribution studies from these studies indicate limited 
spread of the AAV2-serotyped vector following subretinal 
administration. An AAV2-REP-1 vector has been administered to at 
least six subjects in the United Kingdom with initial results showing 
no significant untoward effects and some indication of efficacy 
(MacLaren et al., 2014; Edwards et al., 2016). These results 
comprising the use of AAV2-hRPE65v2 in non-clinical and clinical 
studies of inherited retinal degeneration due to autosomal-recessive 
RPE65 gene mutations, along with non-clinical studies of the 
AAV2-hCHM vector both in vitro and in mice (Vasireddy et al., 
2013), support further clinical investigation.     
In this regard, production and characterization of AAV vectors at 
the Center for Cellular and Molecular Therapeutics (CCMT) at The 
Children’s Hospital of Philadelphia (CHOP) have been successfully 
completed for several vectors used in clinical gene transfer studies. 
Over the years, the CCMT Clinical Vector Core (CVC) has 
developed and implemented a number of processing steps to 
increase the uniformity and potential efficacy of AAV vectors. The 
manufacturing process for AAV vectors at the CCMT CVC 
typically results in a homogeneous product with substantial 
reduction of empty capsid particles. Reducing the empty capsid 
particles in the final vector product may have an advantage when 
delivering an AAV vector to the eye, by decreasing vector capsid 
exposure and potentially mitigating unwanted immune responses. In 
addition, substantial reduction of empty capsids ensures that cell 
surface receptors in the relatively restricted area of the injection bleb 
are not blocked by empty capsids, but rather that each vector 
particle that attaches to cell surface receptors carries a DNA 
payload.    
 

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Eligibility Criteria: 
1. Willingness to adhere to the clinical protocol and 5-year 
long-term follow-up as evidenced by written informed 
consent 
2. Male at least 18 years of age  
3. CHM gene mutation (confirmed by a Clinical Laboratory 
Improvement Amendments (CLIA)-certified laboratory)  
4. Central visual field (VF) < 30° in at least 6 of the 24 
meridians (using Goldmann perimetry III4e isopter) in the 
eye to be injected for the initial three subjects in Dose Group 
1; central visual field (VF) < 30° in any of the 24 meridians 
(using Goldmann perimetry III4e isopter) in the eye to be 
injected for the remainder of subjects. Central visual field is 
defined as field contiguous with fixation, not including 
isolated islands. 
5. Any evidence of functioning outer retinal cells within the 
central 10°, as defined by intact visual field, optical 
coherence tomography (OCT) evidence of preserved outer 
nuclear layer in the retina, or ophthalmologic evidence of 
intact retinal pigment epithelium, as detected by 
ophthalmoscopy and confirmed by fundus photography 
Exclusion Criteria 
1. Females and individuals less than 18 years of age 
2. Unwilling to use barrier contraception methods for a period 
of four months following vector administration 
3. Previous history of ocular inflammatory disease (uveitis) 
4. Prior intraocular surgery within six months 
5. Participation in a previous gene therapy research trial within 
one year of enrollment or participation in any other ocular 
gene therapy trial 
6. Participation in a clinical study with an investigational drug 
in the past six months 
7. Grossly asymmetrical disease, or other eye morbidity, which 
may render the contralateral eye ineffective as a control. 
Grossly asymmetric disease would include situations where 
one eye has significantly worse visual acuity (defined as a 
difference of more than 15 letters on an Early Treatment of 
Diabetic Retinopathy Study (ETDRS) chart) or significantly 
worse visual field (defined as a difference of > 10°) than the 
other eye. 
[Note: Intraretinal fluid and/or cystoid macular edema are 
not exclusion criteria due to the prevalence of these findings 
in patients with choroideremia.] 

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8. Visual acuity < 20/200 on standard ETDRS testing in the 
eye to be injected 
9. Presence of disease which may preclude the subject from 
participation in this trial, for example, cornea or lens 
disorders that impede retinal evaluation, systemic disease 
causing retinal changes such as diabetic retinopathy, 
neurologic disease which may confound study endpoints, 
malignancies which may be treated by local therapies (e.g., 
radiation) to the eye or central nervous system (CNS), or 
hematologic or other diseases which may complicate 
assessment of research outcomes; primary or acquired 
immune deficiency, because of the increased risk of 
opportunistic infections, such as CMV retinitis 
10. Use of medications known to be neuroprotective and 
possibly beneficial for retinal disease (such as valproic acid) 
or retino-toxic (such as isotretinoin, thioridazine, 
chloroquine, and hydroxychloroquine) that could potentially 
interfere with the disease process and/or cause ocular 
adverse events; individuals who discontinue use of these 
compounds for 6 months may become eligible. 
11. Individuals incapable of performing visual function testing, 
e.g. visual field and microperimetry testing, for reason other 
than poor vision 
12. Any other condition that would not allow the potential 
subject to complete follow-up examinations during the 
course of the study and, in the opinion of the Investigator, 
makes the potential subject unsuitable for the study 
 
Number Of Subjects  
 
Up to a total of 15 evaluable subjects that receive AAV2-hCHM.  
Study Duration 
Each subject’s participation will last for approximately two years in 
the active phase of the study and up to 5 years following vector 
administration for long-term follow up. The study is expected to be 
conducted over approximately 3.5 years for recruitment and study 
enrollment, including the two-year active phase follow-up. The 
long-term follow-up (LTFU) phase will be conducted with a 
duration of up to 5 years following vector administration.  
 
Study Phases 
Screening/Baseline 
Study Intervention 
Follow-Up   
Screening/Baseline: Initial screening for eligibility is based 
primarily on documentation of the underlying CHM gene mutation 
by a CLIA-certified laboratory in an individual with choroideremia; 
this genetic diagnosis is typically obtained through standard clinical 
care prior to enrollment in a clinical study. If the screening indicates 

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Long-Term Follow-
Up 
potential eligibility, gene therapy informed consent is conducted 
prior to the extensive Baseline evaluation. The Baseline evaluation 
will be comprised of medical history and comprehensive visual and 
laboratory assessments (including confirmation of genetic diagnosis 
if adequate records are not available). If all of the criteria indicate 
study eligibility, the subject is offered the opportunity of vector 
administration and participation in the active phase of the study.  
Study Intervention (Vector Administration): After confirmation of 
eligibility and subject agrees to study entry, the investigational 
product (AAV2-hCHM) is administered in the operating room on 
Day 0 via unilateral subretinal injection under general anesthesia to 
the subject’s non-preferred eye (or the eye with worse visual acuity 
if the subject has no preference). The subject is maintained for up to 
24 hours in a supine position following the procedure. The subject 
may be discharged during this 24-hour time period, if stable, 
provided the post-operative supine positioning can be maintained.   
Active Phase Follow-Up: Analyses will include safety endpoints 
such as adverse events, comprehensive blood and urine laboratory 
tests, vector presence in blood and tears, pregnancy outcomes (in 
female partners of subjects), as well as ophthalmologic safety and 
efficacy endpoints including ophthalmic examination, and measures 
of visual function, functional vision, ophthalmologic imaging, and 
quality of life (QOL) questionnaire. The schedule of evaluations in 
the active phase will be conducted over an approximately 2-year 
period post vector administration to assess safety and efficacy of 
AAV2-hCHM (including the administration), comparing the 
findings obtained longitudinally from the injected eye with those of 
the uninjected eye serving as the control.  
Long-Term Follow-Up: LTFU, up to 5 years following vector 
administration, will be conducted to characterize the clinical 
outcome and the type and seriousness of adverse events following 
the AAV2-hCHM gene transfer, as specified in the January 2020 
FDA guidance document entitled, “Long Term Follow-Up After 
Administration of Human Gene Therapy Products.” Assessments 
will include adverse events, history, physical and ophthalmic 
examinations, blood tests, urinalysis, pregnancy outcomes (in 
female partners of subjects) and retinal/visual function tests. All 
adverse events will be collected during the LTFU period and 
reporting will focus on those events related to the prior 
administration of AAV2-hCHM and the development or 
exacerbation of oncologic, hematologic, neurologic, and 
autoimmune events as specified in the November 2006 FDA 
guidance document entitled, “Gene Therapy Clinical Trials – 
Observing Subjects for Delayed Adverse Events.” The LTFU phase 

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seeks to provide longitudinal information, and should adverse 
events occur, more timely discovery and treatment. 
 
Efficacy Evaluations 
Efficacy will be evaluated primarily by assessing visual function, as 
measured by standard ophthalmological tests: Ophthalmologic 
examination, visual acuity (VA) by ETDRS testing, visual fields 
(VF) by Humphrey visual field testing, including foveal and 
macular thresholds, Goldmann visual field test, and Octopus kinetic 
visual field test (for subjects whose central visual field is >20° in at 
least 1 of the 24 meridians at the Screening/Baseline visit using 
Goldmann perimetry III4e isopter), as well as central field testing, 
reading speed, contrast sensitivity, and color vision testing. 
Additional efficacy endpoints will include: microperimetry, full-
field light sensitivity threshold testing, and quality of life (QOL) 
questionnaire. Anatomical structures will be imaged by fundus 
photography (including low intensity autofluorescence) and by 
OCT. 
 
Pharmacokinetic 
Evaluations 
There will be no pharmacokinetic evaluations. However, there will 
be assessment of post-administration vector shedding (see Safety 
Evaluations, below).     
 
Safety Evaluations 
This is primarily a safety study to determine whether subretinal 
administration of AAV2-hCHM is safe for use in subjects with 
choroideremia. Adverse event collection and comprehensive 
laboratory safety evaluations will be conducted at regular intervals 
to assess safety. Viral vector administration may result in immune 
responses against the vector transgene product (REP-1 protein) or 
the AAV2 capsid; responses will be evaluated. Pregnancy outcomes 
(in female partners of subjects) will be assessed. If there is no 
limiting toxicity, up to 15 subjects will be entered at the two 
different dosage groups. Safety tests will include those for the 
presence of vector in tears and blood (vector shedding).  
 
Statistical And Analytic 
Plan 
Because of the small sample size of the proposed study, the 
statistical power of the data is limited. The statistical plan will be 
based primarily on safety and tolerability of the vector, and 
secondarily on efficacy (see comments under ‘Safety Evaluations’, 
above). Determining limiting toxicity will be the primary statistical 
endpoint.   
 
Data And Safety 
Monitoring Plan 
Monitoring gene therapy studies occurs at different levels of 
regulatory oversight, by several governing agencies. The day-to-day 

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assessment of safety will be the responsibility primarily of the PI. 
An independent DSMB will oversee data and safety monitoring, 
with interval meetings based on DSMB guidelines. Any serious 
adverse event will be reported in the appropriate time-frame to the 
Sponsor, and as required to each of the regulatory agencies (FDA, 
DSMB, institutional review board (IRB) and institutional biosafety 
committee (IBC)).  
 
 

Schedule of Evaluations 
 
 
 
 
 
 
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Notes for Table of Clinical Assessments: 
 
1 Day 7 evaluations, including an additional ophthalmic exam, will only be conducted if ocular inflammation is present at the Day 3 visit 
2 Blood/tear polymerase chain reaction (PCR) will be continued until two consecutive specimens test negative: Tear and blood collection will 
occur at each study visit until this result is obtained 
3 Day 0 = Day of vector administration: Unilateral subretinal dosing of AAV2-hCHM is conducted in the subject’s non-preferred eye (or the eye 
with worse visual acuity if the subject does not have a preference) starting sequentially first with the Dose Group 1 (subjects #1-5, up to 5x1010 
vg/eye) followed by Dose Group 2 (subjects #6-15, up to 1x1011 vg/eye). It should be noted that the degenerative component of the disease may 
preclude delivery of the full dose, in which case the dose given will be based on vector concentration and total volume administered (up to 300 
µL).  
4 Octopus kinetic visual field test will only be done to subjects whose central visual field is >20° in at least 1 of the 24 meridians at the 
Screening/Baseline visit using Goldmann perimetry III4e isopter. 
 
 
             

 
 
 
 
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1 
BACKGROUND INFORMATION AND RATIONALE 
1.1 
Introduction 
1.1.1 Choroideremia and Gene Therapy 
Choroideremia is a degenerative X-linked retinal disease characterized by deletions or 
mutations in the choroideremia (CHM) gene at Xq21.2 (OMIM gene locus #300390) resulting 
in defective or absent Rab escort protein-1 (REP-1), the protein encoded by the CHM gene 
(Seabra et al., 1993; Seabra et al., 1995; Cremers et al., 1994; Alexandrov et al., 1994). 
Normally, Rab proteins are escorted by REP-1 to Rab geranylgeranyltransferase (Rab 
GGTase), which attaches geranylgeranyl groups to Rab proteins at the carboxy terminal ends 
(prenylation), an essential process that activates Rab proteins for their role in intracellular 
vesicular transport (Alexandrov et al., 1994). In this way, REP-1 binds to newly synthesized 
Rab proteins, presents them to Rab GGTase, and delivers the geranylgeranylated Rab proteins 
to their target membranes.   
Absence or deficiency of REP-1 due to deletions or mutations in the CHM gene leads to 
cellular apoptosis and degeneration of the retinal pigment epithelium, choroid, and retinal 
photoreceptors. In normal retinas, the CHM gene is expressed in multiple cell types, including 
retinal pigment epithelium, photoreceptors and choroidal cells, even though there is evidence 
that the RPE cell is the primary disease-causing cell type. This evidence stems from 
observations in conditional knockout mice (Tolmachova et al., 2006; Tolmachova et al., 2012) 
and from studies evaluating efficacy of lentivirus-mediated gene transfer (which targets RPE 
cells preferentially) (Tolmachova et al., 2012). The AAV serotype 2 vector, which targets RPE 
cells primarily (and other retinal cell types secondarily) is thus an ideal vector for 
choroideremia. Unlike lentivirus, which typically integrates into genomic DNA, AAV2 
remains predominantly as a stable episome over the long-term (McCarty et al., 2004; Mingozzi 
and High, 2011). Because it is predominantly extra-chromosomal, in vivo results indicate that 
AAV vectors carry a low risk of insertional mutagenesis (Li et al., 2011; Donsante et al., 
2007). 
Clinically, choroideremia is diagnosed in affected males who manifest night blindness in 
childhood, followed by progressive constriction of visual fields, usually symptomatic in the 
teenage to young adult years, and eventual total blindness. The pathological hallmarks of this 
X-linked disease, with a population prevalence of approximately 1:50,000-1:100,000 
(Foundation Fighting Blindness, 2012; Genetics Home Reference, 2008; Orphanet, 
Choroideremia; Weckerle, Encyclopedia of Molecular Mechanisms of Disease) are 
degeneration of the choroicapillaris, as well as retinal pigment epithelium and photoreceptors 
(MacDonald et al., 2009). The disease course is variable, with early clinical manifestations of 
decreased dark adaptation, progressing to decreased peripheral vision, followed eventually by 
loss of central vision, generally occurring later in life. In some patients, blindness occurs after a 
prolonged course. 
Choroideremia is a disease candidate for gene transfer for the same reasons that other inherited 
retinal degenerative diseases are candidates for AAV-mediated vector delivery: a) The small 
and localized nature of the target area, namely the retina, with a radius of approximately 15 
mm; b) the circumscribed environment of the target organ, the eye; c) the tissue boundaries 

 
 
 
 
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surrounding the area to be injected, which minimizes exposure of other cells to the vector and 
allows effective treatment with a relatively small vector dose; and, d) the favorable immune 
status of the eye with respect to viral vector-mediated gene transfer (Anand et al., 2002). 
Immune regulation processes in the eye can be so effective that antigens encountered in the eye 
potentially result in a specific tolerization known as anterior chamber-associated immune 
deviation (ACAID) (Streilein et al., 1980).  
The justification for a gene transfer approach for choroideremia is that a corrective gene 
delivered to the retina and RPE early enough in the clinical course may halt further 
degeneration of the RPE, retinal vasculature and photoreceptors. If this hypothesis is correct, 
visual stability or improvement may result from gene delivery (MacLaren et al., 2014; Edwards 
et al., 2016). Based on the preliminary data from gene therapy studies conducted by 
investigators in the U.S. and EU using an AAV2-serotype vector for inherited retinal 
degeneration due to autosomal-recessive RPE65 gene mutations (LUXTURNATM, FDA BLA 
#125610; Bainbridge et al., 2008; Hauswirth et al., 2008; Maguire et al., 2008; Maguire et al., 
2009; Simonelli et al., 2010; Bennett et al., 2012; Jacobson et al., 2012; Cideciyan et al., 2013; 
Bennett et al., 2016), this prospect seems feasible for choroideremia.  
1.1.2 Biology of Adeno-Associated Virus (AAV) Vectors 
Adeno-associated virus is a non-enveloped, replication-defective parvovirus that has not been 
associated with human disease. AAV vectors are derived from the parent virus by removing all 
of the viral elements except for the inverted terminal repeats (ITR) and inserting the gene or 
genes of interest and their associated regulatory elements (Samulski et al., 1982; Samulski et al., 
1987). The long-term safety of these vectors in humans is unknown; however, AAV vectors have 
been delivered to over 300 human subjects at this point, in trials for cystic fibrosis, rheumatoid 
arthritis, inherited retinal degeneration due to autosomal-recessive RPE65 gene mutations, α1-
antitrypsin deficiency, as well as hemophilia, and have been remarkably free of vector-related 
adverse events (Mingozzi and High, 2011). In October 2012, the European Commission granted 
marketing authorization for Glybera® under exceptional circumstances as a treatment for adult 
patients diagnosed with familial lipoprotein lipase deficiency (LPLD) confirmed by genetic 
testing and suffering from severe or multiple pancreatitis attacks despite dietary fat restrictions. 
This is the first AAV-based vector product granted marketing authorization in an ICH region, 
and is administered intramuscularly. 
AAV vectors do not require actively dividing target cells to achieve efficient transduction, as 
demonstrated in post-mitotic cells of brain, muscle, liver, and retina in vivo (Mingozzi and 
High, 2011; Maguire et al., 2008; Maguire et al., 2009). Also, at least in animal studies, there is 
no immune response directed against the transduced cell, likely because all of the viral genes 
have been removed. In the eye, an immune-privileged site, the immune response against AAV 
capsid is negligible to weak (Anand et al., 2002), and has not precluded effective transgene 
expression following subsequent administration to the contralateral eye (Bennett et al., 2012). 
This absence of immune response accounts, at least in part, for prolonged (months to years) 
transgene expression observed in animals following a single administration of an AAV vector. 
Several groups have established that AAV efficiently transduces retinal pigment epithelium 
following a single administration into the subretinal space, resulting in long-term, (11 years in 
animals, > 6 years in humans), dose-dependent transgene expression (Bennett et al., 2012; 

 
 
 
 
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Cideciyan et al., 2013). This finding supports the anecdotal results of long-term (up to 10 
years) expression in human skeletal muscle, targeted in earlier clinical gene transfer studies of 
hemophilia (Manno et al., 2003; Jiang et al., 2006; Buchlis et al., 2012).  
1.1.3 Choroideremia as a Model for Gene Therapy 
Retinal degenerative diseases such as choroideremia are rational targets for gene therapy using 
AAV. First of all, the use of an AAV2 pseudotyped vector has shown safety and utility in both 
animal models and human subjects with autosomal-recessive RPE65 gene mutations (Acland et 
al., 2001; Acland et al., 2005; Maguire et al., 2008; Bainbridge et al., 2008; Hauswirth et al., 
2008; Maguire et al., 2009; Amado et al., 2010; Mingozzi and High, 2011; Bennett et al., 
2012; Jacobson et al., 2012; Cideciyan et al., 2013) providing impetus to develop research 
programs for other retinal degenerative diseases that have no currently effective treatment. 
Since the degenerative changes of choroideremia generally progress slowly over time, the 
results of unilateral vector administration can be assessed and verified, when compared to the 
uninjected control eye. The subretinal space has been shown to provide a favorable 
environment for AAV to deliver a normal gene to the RPE layer (Bennett et al., 1999; Acland 
et al., 2001; Jacobson et al., 2006b; Maguire et al., 2008; Bainbridge et al., 2008; Hauswirth et 
al., 2008; Maguire et al., 2009; Amado et al., 2010), and the limited size of the target allows 
for efficient transduction of retinal cells. Both in vitro and in vivo results demonstrate that the 
REP-1 protein is translated at levels potentially sufficient to result in a clinically relevant 
change within the eye (see sections 1.4.1 and 1.4.2, below). Importantly, since high levels of 
the transgene protein do not appear to be toxic (Tolmachova et al., 2012), over-expression of 
REP-1 protein that may potentially occur in the context of gene therapy is not predicted to be 
harmful. Finally, since the eye is immune-protected, the relative lack of an immune response 
against the capsid protein of AAV2 and against the transgene protein may provide the ideal 
milieu for advantageous long-term transgene expression.   
1.2 
Name and Description of Investigational Product  
The investigational product is AAV2-hCHM, an adeno-associated viral vector pseudotyped 
with AAV2 capsid, and the human CHM gene open reading frame under the regulatory control 
of the hybrid chicken β actin (CβA) promoter/CMV enhancer upstream of CβA exon 1 and 
intron (Figure 1). AAV2-hCHM is produced according to good manufacturing practice (GMP) 
guidelines, with substantial removal of empty capsid particles from the final product. The 
investigational product AAV2-hCHM will be administered by unilateral administration into the 
subretinal space of eligible, male subjects with choroideremia due to mutations in the CHM 
gene. 

 
 
 
 
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receptors in the relatively restricted area of the injection bleb are not blocked by empty capsids, 
but rather that each vector particle that attaches to cell surface receptors carries a DNA 
payload.    
1.3 
Findings from Non-Clinical and Clinical Studies  
The in vitro and in vivo pharmacology and toxicology described in the sections below 
demonstrate that AAV2 vectors can be safely delivered to the subretinal space, and that the 
vectors can transduce sufficient retinal pigment epithelium cells in the target area to result in 
therapeutic levels of transgene protein expression. The abundance of non-clinical, and clinical 
data in the sections below demonstrate the preliminary safety and efficacy findings of the 
AAV2-hRPE65v2 vector, an AAV2-pseudotyped vector used for inherited retinal degeneration 
due to autosomal-recessive RPE65 gene mutations. This is a meaningful starting place, since 
the AAV2 capsid is the same for AAV2-hRPE65v2 and AAV2-hCHM, and the vector 
production and purification methods are essentially identical for these two vectors. The sponsor 
proposes review of the safety and biodistribution results of AAV2-hRPE65v2 to help support 
the use of the identically encapsidated AAV2-hCHM, for choroideremia. The RPE65 gene 
therapy data that supports this proposed CHM clinical study is contained in FDA BLA 
#125610 and will be outlined in this protocol.   
For the proof-of-concept studies outlined in the sections below, we start with review of those 
for AAV2-hRPE65v2, followed by those of AAV2-hCHM. The non-clinical safety and 
efficacy results using AAV2-pseudotyped vectors encoding RPE65 in mice, dogs, and non-
human primates have been described in a number of peer-reviewed publications (Acland et al., 
2001; Dejneka et al., 2004; Acland et al., 2005; Jacobson et al., 2005; Jacobson et al., 2006a; 
Jacobson et al., 2006b; Jacobs et al., 2006; Bennicelli et al., 2008; Amado et al., 2010), as 
briefly outlined in section 1.3.1. The safety and efficacy of clinical trials using the AAV2-
hRPE65v2 vector are described below in section 1.3.2, including the Phase 1 clinical trial, as 
well as the follow-on study of administration to the contralateral eye. The initial results of 
AAV2-hCHM in cells and mice and the results of the pharmacology/toxicology study of 
AAV2-hCHM in non-human primates are summarized in Section 1.4.  
1.3.1 Non-Clinical Studies of AAV2-hRPE65v2 
In Vitro Studies Using AAV2-hRPE65 
Numerous in vitro studies of several iterations of AAV2-hRPE65 vectors were conducted to 
develop the clinical vector AAV2-hRPE65v2, for retinal disease due to RPE65 gene mutations. 
Initial studies of AAV transduction, using AAV-RPE65, of primary cell cultures of canine RPE 
cells, in which the vector was prepared, demonstrated expression of the RPE65 protein without 
toxicity (Acland et al., 2001). To enhance safety, AAV2-hRPE65v1 was produced, a vector 
similar to that used in the initial proof-of-concept studies, except that the plasmid used to 
generate the vector was lengthened by insertion of a stuffer sequence. This modification 
prevents reverse packaging from the AAV inverted terminal repeats (ITRs), possible when the 
size of the vector plasmid backbone is less than the packaging limit of AAV. To enhance 
efficacy, introduction of a Kozak sequence (Kozak, 1997) and modification of the splice 
acceptor site were performed in the development of AAV2-hRPE65v2. Importantly, AAV2-
hRPE65v2 transduction of cells in vitro (normal and mutant Briard RPE) resulted in specific 

 
 
 
 
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expression of both hRPE65 mRNA, as detected by reverse transcriptase polymerase chain 
reaction (RT-PCR), and of RPE65 protein as detected by immunohistochemistry. No increase 
in the basal apoptotic rate of either normal or mutant Briard RPE cells occurred after 
transduction with AAV2-hRPE65v2 or AAV-CMV-eGFP (used as a control) at any 
multiplicity of infection (MOI) tested (102 to 105). 
In Vivo Studies Using AAV2-Pseudotyped RPE65  
Many in vivo studies using AAV-RPE65 as well as studies using the current version, AAV2-
hRPE65v2, showed favorable toxicity outcomes not only in animal models of disease but also 
in normal animals, as well as efficacy in animal models of disease.   
In Vivo Studies Using AAV-RPE65  
Administration of AAV-RPE65 was safe and effective in a number of animal models of mice 
and dogs (Acland et al., 2001; Dejneka et al., 2004; Acland et al., 2005; Jacobson et al., 
2006b). Biodistribution studies in dogs showed little vector outside the eye (vector in the heart 
and diaphragm in one dog, and a single submandibular lymph node in two others, as described 
in Jacobson et al., 2006b), without germline transmission documented in any animal study. 
Subretinal injections of AAV-RPE65 (purified research-grade vector, generally containing a 
syngeneic open reading frame of RPE65), restored vision in RPE65 “knockout” mice and in 
dogs which have naturally occurring mutations in RPE65. Importantly, transgene expression 
persisted after subretinal administration of AAV for the duration of the study and/or lifetime of 
animals that were treated in the laboratory, approximately 2.5 years in mice and greater than 
ten years in dogs. Age-dependent efficacy has been demonstrated in both mice and dogs, 
probably reflecting the time-course of retinal degeneration in these animals. 
In Vivo Studies Using AAV2-hRPE65v1 
A non-clinical in vivo toxicity study in normal dogs using AAV2-hRPE65v1 (vector plasmid 
with stuffer sequence to allow less helper plasmid contamination of final vector product), 
designed in consultation with FDA, examined histopathology and biodistribution at early (3 
week) and late (3 month) time-points. The dose utilized in this good lab practice (GLP) study 
(1.5x1012 vg/eye) was 100-fold higher than the RPE65 Phase 1 low dose and 10-fold higher 
than the RPE65 Phase 1 high dose. No systemic toxicity or general ocular toxicity was 
observed in the normal dogs injected at this dose. All animals remained healthy and active 
through the study period. There was no evidence of systemic or CNS exposure to the vector 
after ocular administration. There was no evidence of abnormal systemic histopathology or 
cell-mediated immune response. However, focal retinal toxicity was apparent histologically at 
the 3-month time-point in regions exposed to the vector. This focal retinal toxicity in dogs at 
the 3-month time-point was addressed in further studies, after modifying the vector construct 
and excipient (see next section, below). 
In Vivo Studies Using AAV2-hRPE65v2  
To summarize, following injection of AAV2-hRPE65v2 prepared by clinical grade methods at 
a dose of 8.25x1010 vg/eye (5.5-fold greater than the low dose of the RPE65 human trial and 
nearly two-fold greater than the proposed low dose of the CHM human trial), affected dogs 
showed improvement in visual parameters, and in marked contrast to dogs injected in the study 

 
 
 
 
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described above, showed only mild focal retinal toxicity. There was no evidence of systemic 
exposure to RPE65 protein at 5 weeks or 3 months after treatment. Antibodies to AAV2 capsid 
were detected at 5 weeks, but were not observed 3 months after treatment. Also, there was 
minimal evidence of RPE65 protein in ganglion cells and in optic nerves and photoreceptors 
(Bennicelli et al., 2008). Importantly, in a follow-up study in Briard (affected) dogs, sequential 
administration of 1.5x1011 vg AAV2-hRPE65v2 to one eye then the contralateral eye was well 
tolerated and resulted in improvements in visual behavior in the animals (Amado et al., 2010). 
Additional non-clinical studies were conducted to address the focal toxicity observed in the 
canine study using AAV2-hRPE65v1 at the three-month time-point (noted above) and to 
examine safety issues with respect to slight modifications that were made to the vector 
sequence and formulation. The changes, which were made to optimize the delivery and 
performance of the vector, are detailed (Bennicelli et al., 2008). Modifications included 
installation of a Kozak sequence at the translation start site of hRPE65 and modification of the 
splice acceptor site. Following detailed studies to assess possible loss and/or inactivation of 
vector using delivery devices, the concentration of Lutrol® F68 (also known as Pluronic F68 
and Poloxamer 188) excipient was increased from 0.0001% to 0.001% (Bennicelli et al., 2008). 
The following non-clinical toxicology studies were performed to evaluate safety and efficacy 
of the modified vector and formulation. 
AAV2-hRPE65v2 Toxicology Study in Non-Human Primates 
To evaluate the safety of AAV2-hRPE65v2, the vector construct used in the RPE65 
clinical study, a non-clinical toxicology study examined late time-points in non-human 
primates (NHPs). The doses utilized in this study (3x1011 vg and 7.5x1011 vg) are two-fold and 
five-fold higher than the high dose of the RPE65 Phase 1 human trial and 20-fold and 50-fold 
higher than the RPE65 human trial low dose cohort. The rationale for using NHPs centered on 
the fact that dog eyes show much higher amounts of inflammation after surgical procedures 
than those of primates and other animals (Acland et al., 2005); further, eyes of NHPs are more 
similar to those of humans than are dog eyes, as primates are the only animals that have a 
macula. Since there is only one amino acid difference between the RPE65 protein of humans 
and non-human primates, whereas there are eight differences between humans and dogs, it 
seemed less likely that the human RPE65 protein would be viewed as a foreign antigen in 
NHPs than in dogs. For both anatomical and immunological reasons, NHPs provide a more 
appropriate model. 
Ten non-human primate eyes (5 animals) were injected at doses of 20-fold (4 eyes, 3x1011 vg 
per eye) and 50-fold (4 eyes; 7.5x1011 vg per eye) of the AAV2-hRPE65v2 human low dose of 
1.5x1010 vg; two eyes were injected with vehicle alone. Final evaluations included ocular 
histopathology and biodistribution. Most eyes showed no inflammation. No retinal 
degeneration was apparent in any eye after necropsy by histopathology, as had been observed 
in the canine toxicology study at the same time-point. This three-month non-clinical study in 
Cynomolgus monkeys demonstrated no ocular toxicity resulting from a single subretinal 
injection of vehicle alone or AAV2-hRPE65v2 at 20- or 50-fold the human low dose and 2- or 
5-fold the human high dose.  
There was no mortality during the study. No test article-related clinical signs of systemic 
toxicity occurred. There were predicted effects of the surgery on ocular examination, including 

 
 
 
 
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mild and reversible inflammatory responses following surgery and alterations in the appearance 
of the retinal fundus due to subretinal injection. In two NHP eyes injected with AAV2-
hRPE65v2, at the far periphery of the retina there was mild perivascular cuffing directed 
toward the vitreous and some inflammatory cells in the vitreous near the optic disc; the changes 
were minor in comparison to the focal toxicity observed in the normal dogs at the 1.5x1012 vg 
dose (100-fold higher than the RPE65 Phase 1 low dose and 10-fold higher than the RPE65 
Phase 1 high dose). There were additional findings that were expected from the subretinal 
injection (dislodged and hypertrophic RPE cells), but no inflammation was observed in the 
subretinal space at either dose tested. At necropsy, there were two unexpected findings: 1) one 
animal had some nodules in its large intestine; and 2) another animal had a few adhesions 
between the diaphragm and the lung. The Sponsor believes that these findings were unrelated 
to the test article. The minimal toxicity observed in this study may reflect the lower dose 
utilized in the NHP study, or may have resulted from the greater sequence conservation 
between humans and NHP RPE65 as compared to canine RPE65.  
There was no evidence of vector spread to pancreas, lung, bone marrow, kidney, testes/ovaries, 
brain, diaphragm, systemic lymph nodes, bone, thymus, heart, urinary bladder, stomach 
(cardiac, fundic and pyloric), colon, skeletal muscle, skin. As expected, intra-ocular fluids 
(anterior chamber fluid and vitreous) of all test article-injected eyes were strongly positive for 
presence of test article at the three-month time-point. Optic nerves (and optic chiasms) of the 
exposed eyes were often weakly positive for test article; this is likely a consequence of 
exposure to retinal ganglion cells, which line the inner surface of the retina and whose axons 
make up the optic nerve. These results are also in agreement with biodistribution results from 
non-clinical canine toxicology studies. An unexpected finding was that samples from spleen, 
and to a lesser extent liver, were mildly positive for the test article. The strength of the signal 
was related to dose, with weak or no signal identified at the lower dose. The non-clinical 
investigators speculate that this is due to migration of immune cells that might have engulfed 
vector or cells exposed to vector to these organs. The animals showed no significant humoral 
antibody response or cell-mediated immunological responses to the test agent.  
Similarly, bilateral sequential administration of 1.5x1011 vg AAV2-hRPE65v2 was well 
tolerated in unaffected non-human primates (NHPs) that had been previously systemically 
exposed to AAV. Those animals showed increases in serum immunoreactivity to AAV2 after 
subretinal injection. This did not prevent safe administration to the contralateral eyes. There 
was also an increase in antibodies directed toward the AAV2 capsids in the anterior chamber 
fluid of the injected eye (only) after unilateral injection. Again, this had no effect on the ability 
to administer the AAV2 safely to the contralateral eye (Amado et al., 2010). 
In summary, simultaneous bilateral administration of AAV2-hRPE65v2 was well tolerated 
both in RPE65 mutant dogs and in normal sighted monkeys, even at doses that are higher than 
those used to date in humans enrolled in the RPE65 Phase 1 study (Bennicelli et al., 2008; 
Amado et al., 2010). In addition, bilateral sequential subretinal administrations were well 
tolerated in dogs and monkeys, even if subsequent injections were carried out several months 
after the first one (Amado et al., 2010). 
1.3.2 Preliminary Clinical Data Using AAV2-Pseudotyped AAV Vectors 

 
 
 
 
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A number of clinical trials with an AAV2-based vector delivering the hREP-1 encoding 
choroideremia gene have been conducted or are currently open in the United Kingdom, 
Canada, United States, and Germany (www.clinicaltrials.gov NCT01461213, NCT02407678, 
NCT02077361, NCT02553135, and NCT02671539). The initial results from six enrolled 
subjects in the United Kingdom receiving 1x1010 vg indicated no clinical significant effects 
from detachment of the fovea and subretinal vector administration and no vector-related 
toxicity (MacLaren et al., 2014). Two patients who had low baseline best corrected visual 
acuity showed gain of letters with the treated eyes six months after vector administration and 
the retinal sensitivity in the treated eyes in all patients was correlated with the vector dose 
administered per mm2 of surviving retina. This early improvement was sustained at 3.5 years 
after vector administration (Edwards et al., 2016). In 2018, a randomized, open label, and 
parallel controlled phase 3 trial (www.clinicaltrials.gov NCT03496012) was initiated in United 
States, Canada, Finland, Germany, Netherlands, and United Kingdom. 
Summary of human studies using AAV2-hRPE65v2 
While there is limited reports of clinical trial data of AAV vector mediated gene delivery for 
choroideremia (MacLaren et al., 2014; Edwards et al., 2016), there are considerable data for 
RPE65 using AAV2. Two Phase 1 studies were conducted for AAV2-hRPE65v2, a Phase 1 
study (101) and a Phase 1 follow-on study (102), involving the same twelve study participants. 
AAV2-hRPE65v2 was initially tested in a Phase 1, first-in-human, open-label, dose escalation 
safety study of patients with inherited retinal dystrophy due to autosomal recessive RPE65 
gene mutations. The primary objective of the 101 study was to determine the safety and 
tolerability of gene transfer by subretinal administration of AAV2-hRPE65v2; a secondary 
objective was to assess both the objective and subjective clinical measures of efficacy in 
patients with RPE65 gene mutations. Eleven of twelve subjects from the 101 study were 
transferred to the 102 study to receive the same vector administration to the contralateral eye in 
the 101 study; one additional subject who participated in the 101 study was not eligible for the 
102 study 
. As such, enrollment for the study was closed 
in 2013. The primary objective of the 102 study was to assess the safety and tolerability of non-
simultaneous, bilateral subretinal administration of AAV2-hRPE65v2 (administration to the 
contralateral eye). The secondary objective was to evaluate the efficacy of administration of 
AAV2-hRPE65v2 to the contralateral eye, using pre-injection measurements of the eye injected 
as a control. At the time of initiation of the 102 study, all subjects had completed at least their 
Year One 101 study visit. A Phase 3, randomized controlled (301) study of AAV2-hRPE65v2 
enrolled twenty-nine participants with all intervention subjects received non-simultaneous, 
bilateral administration of AAV2-hRPE65v2. The objectives of the 301 study are to assess the 
safety, tolerability, and efficacy of sequential, bilateral, subretinal administration of AAV2-
hRPE65v2 to subjects with RPE65 gene mutations. In addition to monitoring for safety and 
tolerability, efficacy is evaluated using a number of retinal and visual function tests. After at 
least one year from the baseline evaluations, nine control participants were able to cross over to 
receive administration of AAV2-hRPE65v2. There were no serious adverse events related to 
AAV2-hRPE65v2 and no deleterious immune responses observed in the Phase 3 trial, or in the 
earlier Phase 1 trials. These trials demonstrated, based on its presumed mechanism of action 
(recovery of biochemical activity of the RPE65 protein) and the broad range of mutations 
included in the clinical trials, AAV2-hRPE65v2 is indicated for the improvement of clinical 
symptoms of vision loss, including nyctalopia, in patients with confirmed biallelic RPE65 

 
 
 
 
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mutation-associated retinal dystrophies (Maguire et al., 2008; Maguire et al., 2009; Simonelli 
et al., 2010; Bennett et al., 2012; Bennett et al., 2016; Russell et al., 2017). AAV2-hRPE65v2 
(voretigene neparvovec, trade name: LUXTURNATM) was approved by FDA on December 19, 
2017 and European Commission on November 23, 2018 for treatment of inherited retinal 
dystrophy patients with confirmed biallelic RPE65 mutations and who have sufficient viable 
retinal cells. 
1.4 
Non-Clinical Studies of AAV2-hCHM  
1.4.1 In Vitro Pharmacology of AAV2-hCHM 
Due to the lack of an animal model of CHM that mimics the human disease, in vitro models of 
the disease were developed for pharmacology studies (Vasireddy et al., 2013). Two induced 
pluripotent stem cell (iPSC) lines (CPS1 and CPS2) were generated from two unrelated 
individuals with confirmed CHM gene mutations. The loss of REP-1 protein was confirmed by 
western blot analysis in both cell lines. A fibroblast cell line was subsequently generated from 
CPS1 and was named CPF1. These cell lines were used to evaluate the AAV2-hCHM vector 
for its ability to confer REP-1 activity.  
Choroideremia patient-derived induced pluripotent stem cells were then transduced with 
AAV2-hCHM at MOIs of 1x102, 1x103, 1x104, 1x105, or 2x105 vg/cell. Wild type induced 
pluripotent stem cells were also plated, but not transduced, and used as a control for normal 
REP-1 expression levels. Expression of REP-1 was evaluated by flow cytometry using an anti-
REP-1 antibody. A qualitative comparison between untransduced wild type cells and CHM 
cells transduced with AAV2-hCHM at an MOI of 1x105 showed similar levels of REP-1 
expression. Transduction of all three cell types (CPS1, CPS2 and CPF1) with AAV2-hCHM at 
an MOI of 2x105 vg/cell resulted in the expression of REP-1 protein (Vasireddy et al., 2013), 
which was primarily localized to the cytoplasm. Additional studies were performed to 
determine if the REP-1 protein encoded by the AAV2-hCHM vector had biological activity. 
REP-1 plays a key role in the post-translational lipid modification of Rab small GTPases 
(Rabs), a process called prenylation. In addition, REP-1 is required for escort of prenylated Rab 
proteins to their target membranes. Thus, to assess the biological activity of REP-1 expressed 
from AAV2-hCHM, assays were employed to determine if Rab proteins were prenylated and 
subsequently escorted to the cell membrane. When CPF1, CPS1 and CPS2 cells were 
transduced with AAV2-hCHM at an MOI of 2x105, the REP-1 protein was capable of 
prenylating its substrate (Rab27) and the amount of Rab27 associated with the cell membrane 
was similar to that seen in unaffected normal cells (Vasireddy et al., 2013). To screen for short-
term toxicity resulting from transduction with AAV2-hCHM, CHO cells were evaluated for 
apoptosis by TUNEL staining following infection by AAV2-hCHM at MOIs of 1x105 or 
2x105. Neither dose of AAV2-hCHM resulted in cell death in the CHO cells. These studies 
demonstrate that AAV2-hCHM is capable of safely delivering a biologically active REP-1 
protein.  
1.4.2 In Vivo Pharmacology and Toxicology of AAV2-hCHM 
One of the challenges in developing gene therapy for CHM is the lack of animal models that 
mimic the human disease. Unfortunately, the mouse model that exists for CHM does not reflect 
the human condition accurately and currently no other small or large animal models with 

 
 
 
 
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choroideremia-like disease have been identified. Thus, the safety of delivering AAV2-hCHM 
to the subretinal space was evaluated in normal wild-type mice and NHPs.   
Safety in Normal Mice 
To evaluate the safety of in vivo expression of AAV2-hCHM, wild type mice were injected 
subretinally with the recombinant adeno-associated viral vectors (rAAV) at a dose of 2.7x1010 
vg/retina. Three weeks post-injection, retinal tissues were collected for protein analysis and 
histologic analyses. Immunoblot analysis of the retinal tissue from these animals confirmed the 
presence of REP-1 protein of the expected size and immunofluorescence analyses of the retinal 
sections confirmed the expression and localization of REP-1 protein to the inner segment and 
outer nuclear layers of photoreceptors and to RPE cells. The number of rows of nuclei in the 
outer nuclear layer was similar in treated and control mice indicating that there were no short-
term degenerative changes in photoreceptors resulting from continuous expression of REP-1. In 
addition, in mice injected with AAV2-hCHM, retinas obtained 3 weeks after subretinal 
injection showed no increase in TUNEL positivity, confirming no cell death. There was also no 
evidence of inflammatory infiltrate in these murine tissues as judged by hematoxylin and eosin 
staining. Thus, our studies using AAV2-hCHM in mice have demonstrated that after subretinal 
injection, the CHM transgene is expressed in both RPE cells and in photoreceptors and no 
toxicity was observed (Vasireddy et al., 2013). 
In summary, delivery of AAV2-hCHM results in the expression of REP-1 in CHO and patient-
derived iPS cells in vitro, and delivery to retinal cells in vivo results in no significant evidence 
of toxicity. The non-clinical data indicate that the REP-1 expressed from AAV2 in patient-
derived iPS cells is able to prenylate its substrate and restore significant trafficking of Rab27 
protein to the surface of the cell. 
Safety in Non-Human Primates 
A toxicology study was designed with assistance of FDA CBER representatives at a pre-IND 
meeting held March 11, 2013. The study was designed to include twelve (12) male non-human 
primates (NHP, Macaca fascicularis, Cynomolgus monkeys) for injection of either vehicle or 
AAV2-hCHM at two different doses and two routes of administration. GMP-process 
comparable AAV2-hCHM vector or vehicle was injected using the same volume 
(approximately 300 µL per retina), as well as the same injection device proposed for the 
clinical study. Each animal was injected bilaterally with either vehicle or vector. The material 
injected included: (a) Vehicle alone subretinally into each eye of two NHPs; (b) AAV2-hCHM 
at 3x1011 vg subretinally into each eye in four NHPs (a dose which is 6-fold greater than the 
proposed starting Dose Group 1 for the human CHM trial, and 3-fold greater than that of Dose 
Group 2 of the human CHM trial; (c) AAV2-hCHM at 7.5x1011 vg per retina, into each eye in 
four NHPs (a dose which is 15-fold greater than the proposed starting Dose Group 1 for the 
human CHM trial, and 7.5-fold greater than that of Dose Group 2 of the human CHM trial; and 
(d) AAV2-hCHM at 7.5x1011 vg into each eye injected intravitreally in two NHPs, to provide a 
”worst case scenario’ for the complications of injection. Half of the animals in each group were 
sacrificed at 3 weeks and the other half at 3 months post-injection. 
After ocular injections and peri-operative administration of sub-conjunctival triamcinolone and 
ophthalmic prednisone and gentamicin, animals were followed for in-life observations and 

 
 
 
 
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blood tests. Blood tests included complete blood counts (CBCs), serum chemistries, and serum 
for immunological parameters (humoral and cellular immune responses against AAV2 and 
antibodies against hREP-1). Tissue histopathology, including ocular histopathology, was 
performed upon sacrifice.  
There were no clinical observations attributed to administration of the test article. There were 
no definitive test article-related changes in hematology parameters or in serum chemistries. 
Immunological testing of serum for anti-AAV humoral activity was as expected, showing 
elevations of anti-AAV2 antibodies in all but one animal receiving AAV2-hCHM; however, no 
cellular immune responses against AAV2 capsid were detected at any time points evaluated. A 
possible low-level antibody response directed against REP-1 was observed in one high dose 
animal, but the data are not conclusive at this time. No test article-related macroscopic or 
microscopic findings in non-ocular tissues were noted at necropsy on Day 21 or 91 and there 
were no test article-related changes in organ weights. Thus, no definitive test article-related 
systemic toxicities were noted following a single subretinal or intravitreal injection of AAV2-
hCHM to Cynomolgus monkeys following either a 21-day or 91-day recovery period. 
Ophthalmologic evaluations revealed that in the large majority of animals the subretinal 
injection caused large retinal bullae that resolved over the course of the study leaving focal 
pigmentary disturbances of the fundus and/or pigment dispersion onto the lens capsules in 
some animals. 
Histopathological examination of the eyes in this study, including those that received vehicle, 
demonstrated changes in the RPE associated with the location of the subretinal injection site. 
Inflammation appeared to be a dose and time dependent phenomenon in most cases, but in all 
eyes that exhibited inflammation, it was graded as no worse than mild. Structural changes in 
the photoreceptors were only identified in two of four eyes injected with the high dose of 
vector and sacrificed at Day 91. These changes were mild and focal in nature, not affecting the 
entirety of the retina.  
The investigative team is not certain if the mild focal loss of photoreceptors observed in two of 
four eyes injected with the high dose of AAV2-hCHM and sacrificed at day 91 was due to 
complications of the subretinal injection, the AAV2 capsid, or expression of human REP-1 in 
cynomolgus monkeys. Since similar and higher doses of AAV2-hRPE65v2 did not lead to 
photoreceptor loss when injected into the eyes of this same species of monkeys, this finding is 
not likely due to the AAV2 capsid. However, it is possible that it could be due to expression of 
a foreign transgene, as there are 18 amino acid differences between the human and cynomolgus 
REP-1 proteins, while there is only a single amino acid difference between the human and 
cynomolgus hRPE65 proteins. Thus, it is more likely that the hREP-1 protein will be viewed as 
a foreign antigen than hRPE65. 
In the Phase 1/2 clinical trial, reaction to the human REP-1 transgene product is less likely. The 
investigative team believes the results obtained in the NHP study support the use of two dose 
levels in the proposed Phase 1/2 clinical trial, namely 5x1010 vg/eye and 1x1011 vg/eye.  
In a separate NHP study, one cynomolgus monkey for each of the dose groups (5x1011, 
7.5x1011, and 2x1012 vg per eye) received AAV2-hCHM via bilateral subretinal injections 
(Couto, 2016 ARVO Meeting; Ignatova, 2016 ASGCT Meeting). Retinal tissues from the 

 
 
 
 
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weeks between vector administrations to successive subjects for the first two subjects of a 
given dose group (study-wide) and at least 2 weeks between vector administrations per clinical 
site for the rest of the subjects in the given dose group. The first dose cohort will contain five 
subjects, barring any dose limiting toxicity, and dose escalation will be contingent upon DSMB 
review of the safety data through at least 30 days for all subjects in the prior cohort. The second 
dose cohort will contain up to ten subjects. 
Potential subjects will be recruited from the clinics of investigative team members, from vision 
centers, and self-referrals via the web-based posting in clinicaltrials.gov. After description of 
the clinical trial to the subject, using the study consent and other approved recruitment 
materials as educational tools, if the subject remains interested in study participation, he will be 
invited to consent for the gene therapy study. The gene therapy Screening/Baseline evaluations 
are comprehensive, and will consist of the review of all relevant medical records and tests 
required to determine study eligibility, including obtaining CLIA-certified laboratory 
confirmation of CHM genotype (if not done previously). If the subject is found eligible for the 
study and interested in pursuing the intervention phase, the subject will be scheduled for vector 
administration conducted under general anesthesia. The surgical procedure for this proposed 
study is similar to that conducted in the Phase 1 and Phase 3 studies of AAV2-hRPE65v2 
(FDA BLA #125610, LUXTURNATM) and is described in the Manual of Procedures.   
As is always the case with subretinal injection, the operating surgeon has latitude in 
administration of the dose, based on the pathophysiology of the subject’s retina. In 
choroideremia in particular, it is anticipated that some patients will have limited access for 
injection due to degenerative disease. For this reason, all doses are specified as “up to 300 µL,” 
recognizing that some subjects may receive a smaller total subretinal volume than 300 µL, and 
as such, may not receive the total dose. This information will be captured should this occur.    
Following unilateral vector administration under general anesthesia, the subjects will be 
followed up comprehensively for safety and efficacy endpoints for two years after injection, 
then up to an additional 3 years (total of up to 5 years) of long-term follow-up. Based on the 
pathophysiology of choroideremia, the investigative team does not anticipate the nearly 
immediate improvement of light sensitivity, to the extent that resulted for the RPE65 gene 
therapy studies (Maguire et al., 2008; Maguire et al., 2009; Bennett et al., 2012). Additionally, 
the visual deterioration of choroideremia generally progresses more slowly than that associated 
with autosomal-recessive RPE65 gene mutations (Rosenberg & Schwartz, 1994; Roberts et al., 
2002). The slower decline of visual function of choroideremia means that the use of the 
uninjected eye as a control for the injected eye becomes more statistically significant as 
sufficient time lapses between injections. Therefore, to minimize risk to subjects, 
administration of investigational product will be done in one eye for this study.         
3.1.1 Screening/Baseline  
Potential subjects will be referred from health professionals who care for patients with 
choroideremia, from clinics of investigative team members, from vision centers as well as 
potential self-referred subjects, and from the website posting on clinicaltrials.gov. For those 
patients who are interested, investigative team members will describe the clinical trial to the 
subject, using the IRB-approved study consent and other approved recruitment materials as 
educational tools. If the available clinical information indicates potential eligibility, and the 

 
 
 
 
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subject is interested in pursuing gene therapy, the subject will go through the consenting 
process, and sign informed consent for the gene therapy study, prior to initiation of 
Screening/Baseline evaluations. The gene therapy study Screening/Baseline evaluations are 
comprehensive, and will consist of the review of all relevant medical records and history, 
physical, ophthalmologic and laboratory evaluations required to determine study eligibility 
including obtaining CLIA-certified laboratory confirmation of CHM genotype (if not done 
previously). If all the inclusion criteria are met, and none of the exclusion criteria pertain (see 
section 3.4), the subject is eligible for the study. If the subject wishes to pursue the intervention 
phase, the subject will be scheduled for subretinal vector administration conducted under 
general anesthesia.   
3.1.2 Study Intervention 
As stated in section 3.1.1 above, if after all the applicable Baseline evaluations, the subject is 
eligible for the study and wishes to pursue the study intervention phase, he will be scheduled 
for subretinal administration of the investigational product. Preoperative tests will be obtained 
as well as anesthesia consultation. If the pre-operative tests and the anesthesia consultation 
confirm acceptability for general anesthesia, the subject will be taken to surgery, placed under 
general anesthesia, and receive one of two different doses of vector, prepared by the 
investigational pharmacy. If baseline tests, preoperative tests, or anesthesia consultation should 
not indicate eligibility, vector administration will be postponed until a date at which eligibility 
criteria are met, or the subject will be withdrawn from the study. The vector will be 
administered unilaterally, to the subretinal space, under general anesthesia according to the 
procedure described in the Manual of Procedures. The eye with worse visual acuity will be 
injected unless the subject prefers that eye, in which case the contralateral (non-preferred) eye 
will be injected. 
Following vector administration, the subject will be kept in a supine position, observed and 
routinely monitored until stable. If no adverse events ensue, and the subject can maintain a 
supine position, the subject will be discharged during the 24-hour post-recovery period and 
scheduled for follow-up evaluation as an outpatient.  
Follow-up Phase 
After vector administration and assessment of tolerability, the two-year active phase of regular 
clinic visits is scheduled to comprehensively monitor safety endpoints and potential efficacy. 
The two-year active phase is reviewed in detail in Section 4. In addition, the subject will 
participate in LTFU for up to an additional 3 years, for a total of up to 5 years, following vector 
administration. The LTFU phase is described in detail in Section 4.5. 
Plans for Follow-On Study  
If the vector product is tolerated and effective in the two dosage groups over the follow-up 
period, the DSMB will discuss the possibility of a  separate follow-on study for a second eye 
injection of the previously uninjected, contralateral eye.  

 
 
 
 
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3.2 Allocation to Study Groups  
This is an open label, non-randomized, inter-subject dose escalation safety study (Phase 1/2) of 
the unilateral administration of two vector doses (up to 5x1010 vg per eye and up to 1x1011 vg 
per eye) in subjects with choroideremia, with at least 2 weeks between vector administrations 
to successive subjects for the first two subjects of a given dose group (study-wide) and at least 
2 weeks between vector administrations per clinical site for the rest of the subjects in the given 
dose group. The Dose Group 1 will be administered vector first, followed by the Dose Group 2. 
Dose escalation will be contingent upon DSMB approval following review of safety data of the 
prior cohort through at least a minimum of 30 days (that is, at least a minimum of 30 days after 
the last subject of the prior cohort is injected). More than fifteen subjects may enroll (signing of 
the gene therapy study informed consent), to produce fifteen evaluable and injected subjects. 
Those subjects who are enrolled and fail to meet eligibility, or who are withdrawn prior to 
vector injection, can be replaced so that up to fifteen evaluable subjects are administered the 
investigational product.  
3.3 Study Duration, Enrollment and Number of Sites 
3.3.1 Duration of Study Participation 
The total active phase study duration is approximately 27 months for each subject. There is an 
approximate 90-day period for verification of study eligibility, followed by 1 day of study 
intervention (vector administration), and 2 years for active phase follow-up. The initial 
approximately 27-month phase is followed by long-term follow-up for a period of up to 5 years 
after vector administration.  
3.3.2 Total Number of Subjects Projected 
Recruitment will stop when fifteen evaluable subjects are identified and have received 
subretinal injection. In the event that vector-related toxicity occurs at a dose level, discussions 
with FDA and the DSMB will ensue to determine whether additional subjects may be enrolled 
at this, or at a lower, dose (see Dosing, section 7.3, below).  
3.4 Study Population (Eligibility Criteria) 
3.4.1 Inclusion Criteria  
1. Willingness to adhere to the clinical protocol and 5-year long-term follow-up as 
evidenced by written informed consent 
2. Male at least 18 years of age 
3. CHM gene mutation (confirmed by a CLIA-certified laboratory) 
4. Central visual field (VF) < 30° in at least 6 of the 24 meridians (using Goldmann 
perimetry III4e isopter) in the eye to be injected for the initial three subjects in Dose 
Group 1; central visual field (VF) < 30° in any of the 24 meridians (using Goldmann 
perimetry III4e isopter) in the eye to be injected for the remainder of subjects. Central 
visual field is defined as field contiguous with fixation, not including isolated islands. 
5. Any evidence of functioning outer retinal cells within the central 10o, as defined by 
intact visual field, optical coherence tomography (OCT) evidence of preserved outer 

 
 
 
 
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nuclear layer in the retina, or ophthalmologic evidence of intact retinal pigment 
epithelium, as detected by ophthalmoscopy and confirmed by fundus photography 
3.4.2. Exclusion Criteria 
1. Females and individuals less than 18 years of age 
2. Unwilling to use barrier contraception methods for a period of four months following 
vector administration  
3. Previous history of ocular inflammatory disease (uveitis) 
4. Prior intraocular surgery within six months 
5. Participation in a previous gene therapy research trial within one year of enrollment or 
participation in any other ocular gene therapy trial 
6. Participation in a clinical study with an investigational drug in the past six months 
7. Grossly asymmetrical disease, or other eye morbidity, which may render the 
contralateral eye ineffective as a control. Grossly asymmetric disease would include 
situations where one eye has significantly worse visual acuity (defined as a difference 
of more than 15 letters on an ETDRS chart) or significantly worse visual field (defined 
as a difference of > 10°) than the other eye 
[Note: Intraretinal fluid and/or cystoid macular edema are not exclusion criteria due to 
the prevalence of these findings in patients with choroideremia.] 
8. Visual acuity < 20/200 on standard ETDRS testing in the eye to be injected  
9. Presence of disease which may preclude the subject from participation in this trial, for 
example, cornea or lens disorders that impede retinal evaluation, systemic disease 
causing retinal changes such as diabetic retinopathy, neurologic disease which may 
confound study endpoints, malignancies which may be treated by local therapies (e.g., 
radiation) to the eye or CNS, or hematologic or other diseases which may complicate 
assessment of research outcomes; primary or acquired immune deficiency, because of 
the increased risk of opportunistic infections, such as CMV retinitis 
10. Use of medications known to be neuroprotective and possibly beneficial for retinal 
disease (such as valproic acid) or retino-toxic (such as isotretinoin, thioridazine, 
chloroquine, and hydroxychloroquine) that could potentially interfere with the disease 
process and/or cause ocular adverse events; individuals who discontinue use of these 
compounds for 6 months may become eligible 
11. Individuals incapable of performing visual function testing, e.g. visual field and 
microperimtery, for reason other than poor vision 
12. Any other condition that would not allow the potential subject to complete follow-up 
examinations during the course of the study and, in the opinion of the Investigator, 
makes the potential subject unsuitable for the study 
Subjects that do not meet all of the enrollment criteria may not be enrolled. Any violations of 
these criteria must be reported in accordance with Sponsor and IRB Policies and Procedures. 
4 
STUDY PROCEDURES 
Subjects may participate in the interventional phase of the study after the nature and purpose of 
the protocol have been explained, written informed consent to participate has been voluntarily 

 
 
 
 
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granted, and the eligibility criteria listed in Section 3.4 have been met. See page xvi for the 
Schedule of Evaluations.  
4.1  Screening/Baseline Visit 
4.1.1 Gene Therapy Consent and Screening/Baseline Evaluations (Within 90 Days of 
Investigational Product Administration at Day 0) 
The Screening/Baseline evaluations will be conducted only after the subject is consented for 
the gene therapy study. The Screening/Baseline evaluations are comprehensive and will consist 
of the review of all relevant medical records and history, physical, ophthalmologic and 
laboratory evaluations required to determine study eligibility, including obtaining CLIA-
certified laboratory confirmation of CHM genotype (if not done previously). The 
Screening/Baseline evaluations will generally be done within 90 days of drug administration. 
The comprehensive tests are scheduled to take one day of testing (8 to 10 hours), but for some 
of the subjects the Screening/Baseline tests may take up to two days to complete all the 
required tests. If all the inclusion criteria are met, without any exclusion criteria (see section 
3.4), the subject is eligible for the study, as assessed by the following:   
• Gene therapy informed consent process (may be more than 90 days prior to vector 
administration) 
• History (and medical chart review) and physical exam, including vital signs  
• Prior and concomitant medications, with no excluding medications  
• Confirmation of mutation affecting the CHM gene, based on CLIA-certified laboratory 
testing (may be more than 90 days prior to vector administration) 
• Blood tests, including virology, hematology, chemistry, peripheral blood mononuclear 
cells (PBMCs) for enzyme-linked immunosorbent spot assay (ELISpot), and reactivity 
to AAV2 capsid 
• Tear collection 
• Urinalysis 
• Ophthalmic examination  
• Fundus photography (including low intensity autofluorescence)  
• Optical coherence tomography (OCT)  
• Quality of life questionnaire 
• Visual/retinal function tests: 
o Goldmann visual fields (III4e isopter) 
o Humphrey visual field tests 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Visual acuity   
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry  
o Full-field light sensitivity threshold testing 
 

 
 
 
 
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4.2 Study Intervention Phase 
If results of the Screening/Baseline evaluations indicate eligibility, and the subject agrees to 
study entry, vector (the investigational product) administration will be scheduled. On the day of 
surgery, vital signs, chemistry, hematology, and urinalysis, will be performed, along with 
specimen collection for vector shedding (Section 4.2.1). If the anesthesia consult clears the 
subject for general anesthesia, the subject will proceed with vector administration under 
general anesthesia (Section 4.2.1). After vector administration (study intervention), there are 
regularly scheduled post-administration tests scheduled over a two-year interval to assess both 
safety and efficacy (Section 4.2.2), as well as for an additional up to 3 years, for a total of up to 
5 years LTFU following vector administration (Section 4.5). Pregnancy outcomes will be 
collected after female partners of subjects consent and authorize collection of medical 
information. Subjects are encouraged to inform the Investigators as soon as a pregnancy occurs 
and when the outcome of the pregnancy is known.  
The subject’s non-preferred eye, or the eye with worse visual acuity if the subject has no 
preference, will be the one receiving the vector administration at the time of surgery. This 
would allow subjects to preserve the better eye in the event that the study product or procedures 
result in further visual deterioration. In patients with choroideremia, the visual function of each 
eye generally parallels that of the contralateral eye.  
4.2.1 Vector Administration (Day 0) 
 
Pre-Operative 
• Vital Signs 
• Chemistry, hematology, urinalysis  
• Blood and tear collection for vector shedding 
• Adverse event and concomitant medication recording 
• Anesthesia consult prior to vector administration (may be done before Day 0) 
 
Vector Administration 
• Vector administration under general anesthesia 
Eligible subjects will be admitted to the outpatient surgical clinic (or alternatively, hospital) on 
the day of AAV2-hCHM vector administration, and anesthesia consultation will be performed 
(on the day of procedure, or before admission). General anesthesia eligibility will be 
confirmed, prior to induction of anesthesia for vector injection. Vital signs, peripheral blood 
specimens, and tear specimen will be obtained before surgical vector administration. An 
intravenous (IV) catheter will be inserted into a suitable peripheral vein, according to the 
anesthesiologist’s orders. Subjects will be taken to the operating room for induction of general 
anesthesia. After induction of anesthesia, the retinal surgeon will administer the protocol-
specified dose of vector.  
More specifically, the investigational product AAV2-hCHM will be thawed and diluted by the 
investigational pharmacy according to the Investigational Drug Data Sheet instructions, and 
kept at room temperature prior to injection. Up to approximately 0.30 mL (300 µL) of the 

 
 
 
 
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investigational product, containing the protocol-specified dose, will be administered to the 
subretinal space using an approved vitreoretinal cannula. The anesthesiologist will monitor 
vital signs during the procedure. On completion of the investigational product administration 
and fluid-air exchange, the vitreoretinal cannula will be withdrawn. Subjects will recover in 
post-anesthesia recovery, and remain until stable. If a subject is able to maintain a supine 
position, they may be discharged once stable, prior to 24 hours post-injection, after a minimum 
4 to 6-hour monitoring period.  
4.2.2 Post-Vector Administration Tests for Active Follow Up Phase 
Day 1 
• Vital signs 
• Hematology, Chemistry, and Urinalysis  
• Blood and tear collection for vector shedding 
• Ophthalmic examination, including visual acuity 
• AE and concomitant medications recording 
• [Post-surgical discharge, if not already discharged on Day 0] 
Day 3 
• Vital signs 
• Hematology, Chemistry, and Urinalysis 
• Blood and tear collection for vector shedding  
• Ophthalmic examination, including visual acuity: Note – If ocular inflammation is 
present at Day 3, an additional visit at Day 7 will be included 
• AE and concomitant medications recording 
 
Day 7 
Only if ocular inflammation is present at Day 3, a Day 7 visit is added 
• Vital signs 
• Ophthalmic examination, including visual acuity 
• AE and concomitant medications recording 
Day 14 
• Vital signs 
• Hematology, Chemistry, and Urinalysis 
• Blood and tear collection for vector shedding, if indicated  
• Ophthalmic examination, including visual acuity  
• AE and concomitant medications recording 
Day 30 
• Blood tests, including hematology, chemistry, PBMCs for ELISpot, and reactivity to 
AAV2 capsid 

 
 
 
 
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• Blood and tear collection for vector shedding, if indicated  
• Ophthalmic examination 
• Fundus photography (including low intensity autofluorescence)  
• OCT 
• QOL questionnaire 
• AE and concomitant medications recording 
• Visual/retinal function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry  
o Full-field light sensitivity threshold testing 
Day 90 
• Blood tests, including hematology, chemistry, PBMCs for ELISpot, and reactivity to 
AAV2 capsid 
• Blood and tear collection for vector shedding, if indicated  
• Ophthalmic examination 
• 
Fundus photography (including low intensity autofluorescence) 
• 
OCT  
• QOL questionnaire 
• AE and concomitant medications recording 
• Visual/retinal function tests: 
o Visual acuity 
o Humphrey visual field tests  
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
Day 180 
• Blood and tear collection for vector shedding, if indicated 
• Ophthalmic examination 
• Fundus photography (including low intensity autofluorescence) 
• OCT 

 
 
 
 
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• QOL questionnaire 
• AE and concomitant medications recording 
• Visual/retinal function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
 
Day 365 
• History and physical exam 
• Blood tests, including hematology, chemistry, PBMCs for ELISpot, and reactivity to 
AAV2 capsid 
• Blood and tear collection for vector shedding, if indicated 
• Urinalysis 
• Ophthalmic examination 
• Fundus photography (including low intensity autofluorescence) 
• OCT 
• QOL questionnaire 
• AE and concomitant medications recording 
• Partner pregnancy outcomes recording 
• Retinal/visual function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
Year 1.5 
• Blood and tear collection for vector shedding, if indicated 
• Ophthalmic examination 
• Fundus photography (including low intensity autofluorescence) 
• OCT 

 
 
 
 
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• QOL questionnaire 
• AE and concomitant medications recording 
• Partner pregnancy outcomes recording  
• Retinal/visual function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
Year 2 
• History and physical exam 
• Urinalysis 
• Blood tests, including hematology, chemistry, PBMCs for ELISpot, and reactivity to 
AAV2 capsid 
• Blood and tear collection for vector shedding, if indicated 
• Ophthalmic examination  
• Fundus photography (including low intensity autofluorescence) 
• OCT 
• QOL questionnaire 
• AE and concomitant medications recording 
• Partner pregnancy outcomes recording  
• Visual/retinal function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Goldmann visual fields (III4e isopter) 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
 
For evaluations after Year 2, the subject will go into the long-term follow-up phase (see section 
4.5). The subject returns to the clinic for follow-up at Year 2.5 and then annual follow-up, done 
in the clinic, for Years 3-5 for safety evaluations, standard ophthalmologic examinations, and 
retinal/visual function tests. The subject is questioned about general and ophthalmic health, as 

 
 
 
 
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well as all adverse events including the development or exacerbation of oncologic, 
hematologic, neurologic, or autoimmune diseases and any female partner pregnancy outcomes.  
4.3 Prior and Concomitant Medication 
All subjects will remain on their usual medications throughout the study interval. Prior 
medications will be recorded, through Day -30 of vector injection; concomitant medications 
will be recorded throughout study participation. All medications that the subject is taking will 
be documented, including dosage, with special note of those that may affect vision (e.g., 
vitamin A preparations).  
Prior and concomitant medications that will be recorded include prescription medications, 
blood products, dietary supplements/vitamins, electrolyte supplementation, and over-the-
counter medications (OTC). Administration of the following will not be recorded, unless the 
Investigator considers this important to the assessment of an adverse event. 
• Intravenous fluids 
• Enteral or parenteral nutrition 
• Electrolyte supplementation 
• Albumin 
• Oxygen 
• Intra-operative medications 
Prior Medications 
A medication history will be taken during the Screening/Baseline period and updated at the 
time of administration of the investigational product (Day 0). Medications used within 30 days 
prior to vector administration, including dosage, will be entered in the case report form (CRF). 
Concomitant Medications 
Concomitant medications taken during the study period, including dosage, will be entered in 
the CRF. 
Prohibited Concomitant Medications 
Use of any of the following medications is prohibited from Day 0 to Year 5: 
• Valproic acid 
• Isotretinoin, hydroxychloroquine, chloroquine and thioridazine    
4.4 Subject Completion/Withdrawal 
Subjects may withdraw from the study at any time without prejudice to their care. As much as 
is feasible, the study team will follow subjects after investigational product administration 
since this gene transfer study offers the potential of single-use, long-term treatment that cannot 
be practically withdrawn. It will be documented whether or not each subject completes the 
clinical study, and the reason for study discontinuation including: consent withdrawn; death; 
lost to follow-up; protocol violation; and Investigator or Sponsor discretion (prior to 
investigational product administration). If the Investigator becomes aware of any serious, 

 
 
 
 
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related adverse events after the subject completes or withdraws from the study, the SAE will be 
recorded in the source documents and entered in the study CRF. 
4.4.1 Early Termination Study Visit 
If the subject withdraws after receiving the investigational product and before the Year 5 visit, 
every effort should be made to arrange an Early Termination Study Visit. The study procedures 
to be done should be identical to those of the next scheduled visit. The visit endpoints may 
consist of the following evaluations: 
• History and physical exam 
• Blood tests, including hematology, chemistry, PBMCs for ELISpot, and reactivity to 
AAV2 capsid 
• Blood and tear collection for vector shedding, if indicated 
• Urinalysis 
• Ophthalmic examination 
• Fundus photography (including low intensity autofluorescence) 
• OCT 
• QOL questionnaire 
• AE and concomitant medications recording 
• Partner pregnancy outcomes recording  
• Visual/retinal function tests: 
o Visual acuity 
o Humphrey visual field tests 
o Goldmann visual fields (III4e isopter) 
o Octopus kinetic visual field test (for subjects whose central visual field is >20° 
in at least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann 
perimetry III4e isopter) 
o Reading speed 
o Contrast sensitivity 
o Color vision test  
o Microperimetry 
o Full-field light sensitivity threshold testing 
 
If the subject withdraws before receiving the investigational product, early termination study 
procedures are not necessary. 
 
4.5   Long-Term Follow-Up  
The LTFU phase is up to 5 years following vector administration, subjects are questioned about 
general and ophthalmic health, all adverse events including the development or exacerbation of 
oncologic, hematologic, neurologic, or autoimmune diseases, as well as any female partner 
pregnancy outcomes. The LTFU phase is drafted based on the January 2020 FDA guidance 
entitled Long Term Follow-Up After Administration of Human Gene Therapy Products. For 
Years 2.5, 3, 4, and 5 visits, subjects return to the clinic for safety evaluations, standard 
ophthalmologic examinations, and retinal/visual function testing. 

 
 
 
 
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LTFU Visits (Years 2.5, 3 to 5): 
o An annual (Years 3 to 5) physical exam with complete history; laboratory 
analysis will include:  
 Hematology (CBC with differential) 
 Chemistry panel (including liver and renal function tests) 
 Urinalysis  
o Ophthalmic evaluations and retinal/visual function testing: 
 Ophthalmic examination 
 OCT 
 Fundus photography (including low intensity autofluorescence) 
 Visual acuity 
 Humphrey visual field test 
 Goldmann visual fields (III4e isopter; only annually) 
 Octopus kinetic visual field test (for subjects whose central visual field 
is >20° in at least 1 of the 24 meridians at the Screening/Baseline visit 
using Goldmann perimetry III4e isopter) 
 Reading speed 
 Contrast sensitivity 
 Color vision test  
 Microperimetry   
 Full-field light sensitivity threshold testing 
 QOL questionnaire 
o Adverse event reporting, including any unexpected illness and / or 
hospitalization. Subjects will be encouraged to monitor themselves and to assist 
in reporting adverse events. All adverse events should be recorded. 
Documentation of adverse events should include causality (unlikely, possibly, 
or probably related) to the vector administration procedure, investigational 
product, study measures and any newly arising or exacerbated clinical events in 
four general disease categories; oncologic, hematologic, neurologic, and 
autoimmune disorders. 
o Investigators will maintain in the case history records of exposures to 
mutagenic agents and other medicinal products along with subjects’ adverse 
event profiles. If, according to the investigator, exposure to a mutagenic agent 
occurred, or a medicinal product was given, prior to and thought to contribute 
to an adverse event, or given as a response to an adverse event, then the 
mutagenic agent or medicinal product will be reported to the Sponsor via case 
report forms. 
o Concomitant medications recording 
o Partner pregnancy outcomes recording 
 
 
 

 
 
 
 
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5 STUDY EVALUATIONS AND MEASUREMENTS 
5.1 Screening/Baseline and Monitoring Evaluations and Measurements 
5.1.1 History and Medical Record Review 
Review of medical records will be conducted, including review of paper and electronic records 
of subjects, to confirm ophthalmologic history, inclusion/exclusion criteria, and pertinent past 
medical history. Those items that will be abstracted from the medical chart (paper and 
electronic) will include age, gender, race (demographic information), relevant past 
ophthalmologic and medical history including visual acuity, visual fields, genotype, 
concomitant medications, laboratory reports, electroretinograms (ERG), fundus photographs, 
optical coherence tomograms, radiological and scanning results, ultrasound results, pathology 
reports, and other relevant clinical information. If the subject is entered on study, the medical 
history will be updated in a longitudinal manner, to determine if any significant events have 
occurred during the course of follow-up, and to document concomitant medication changes.  
5.1.2 Physical Examination 
Screening/Baseline and interim physical examinations will include measurements of vital signs 
as well as general physical examination. The Investigators, or qualified designee, will perform 
physical examinations and measure body weight and height at the time points specified in the 
schedule of assessments. In addition, symptom-oriented physical examinations will be 
performed when clinically indicated. Clinically relevant abnormalities prior to the first dose of 
investigational product will be recorded as medical history; clinically relevant abnormalities 
after the first dose of investigational product will be recorded as AEs. 
5.1.3 Laboratory Evaluations 
Blood sampling will be performed for the following standard clinical laboratory evaluations 
(see Table 5.1.3.1); repeat analysis and/or additional sampling and testing will be performed 
when clinically indicated: 
• 
Sequence analysis of the CHM gene by a CLIA-certified laboratory 
• 
Hematology (CBC and differential) 
• 
Chemistry panel to include liver and renal function tests  
• 
Virology testing to include HIV screen 
Urine testing will be performed by standard clinical laboratory analyses (see Table 5.1.3.1); 
repeat analysis and/or additional sampling and testing will be performed when clinically 
indicated: 
• 
Urinalysis (UA) including pH, color, and microscopic exam 
Analysis will be performed for the following research laboratory evaluations (see Table 
5.1.3.2): 
• 
AAV Viral Capsid Antibody 
• 
PBMC for ELISpot  
• 
Whole blood and serum for PCR analysis (vector shedding) 

 
 
 
 
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• 
Tears collected for vector shedding by PCR analysis 
 
5.1.3.1 Table: Summary of Clinical Laboratory Tests 
Category 
Tests 
CHM gene analysis 
Sequence/mutation analysis by CLIA-certified laboratory 
Hematology 
CBC and differential 
Chemistry panel 
Standard panel per clinical laboratory (including liver and 
renal function tests) 
Virology tests 
Screening tests for HIV  
Urinalysis 
Standard urinalysis per clinical laboratory 
 
5.1.3.2 Table: Summary of Research Laboratory Tests1 
Category 
Tests 
AAV Viral Capsid 
Antibody 
Measurement of antibody against AAV viral capsid, serotype 
2  
PBMC for ELISpot  
PBMC evaluation for IFN γ to evaluate activation of immune 
response 
Whole blood and serum for 
vector sequences 
Blood specimens are collected, DNA is extracted, and PCR 
analysis conducted 
Tears for vector sequences 
Tear specimens are collected, DNA is extracted, and PCR 
analysis conducted 
1Each test is conducted according to Sponsor or designee standard operating procedure (SOP). 
Ophthalmic tests will be performed for the following standard and research evaluations (see 
Table 5.1.3.3): 
• Ophthalmic examination 
• Visual acuity 
• Humphrey visual field tests 
• Octopus kinetic visual field test (for subjects whose central visual field is >20° in at 
least 1 of the 24 meridians at the Screening/Baseline visit using Goldmann perimetry 
III4e isopter) 
• Reading speed 
• Contrast sensitivity 
• Color vision test  
• Microperimetry 
• Full-field light sensitivity threshold testing 
• Fundus photography (including low intensity autofluorescence) 
• OCT 
• QOL questionnaire 

 
 
 
 
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5.1.3.3 Table: Summary of Ophthalmic Tests & Evaluations1 
 
Category 
Tests 
Visual Function 
Ophthalmic examinations, using standard instruments and 
methods 
Visual Acuity (ETDRS) 
Goldmann Visual Field Test (III4e isopter)  
Humphrey Visual Field Tests 
Octopus Kinetic Visual Field Test2 
Contrast Sensitivity  
Color vision test  
Microperimetry 
Full-field Light Sensitivity Threshold Testing  
Functional Vision 
Reading Speed 
Imaging 
 
 
Fundus Photography  
Optical Coherence Tomography (OCT), to measure retinal 
thickness 
Evaluation of activities of 
daily life 
QOL Questionnaire 
1Each test is conducted according to standard ophthalmology office practice or Sponsor or designee SOP. 
2Octopus kinetic visual field test will only be done to subjects whose central visual field is >20° in at least 1 of the 
24 meridians at the Screening/Baseline visit using Goldmann perimetry III4e isopter. 
5.2 Efficacy Evaluations 
Evaluations will be made for visual acuity, Goldmann and Humphrey visual field tests, 
Octopus kinetic visual field test, reading speed, contrast sensitivity, color vision test, 
microperimetry, full-field light sensitivity threshold testing, fundus photography (including low 
intensity autofluorescence), optical coherence tomography (OCT), and QOL questionnaire. 
Each of these tests is either a standard clinical test done according to standard clinical practice 
or performed by the investigative team according to Sponsor SOP.  
Visual Acuity: Visual acuity measures will document any change in central vision, the ability 
to resolve standard optotype images presented as optotypes/letters corresponding to different 
visual angles, i.e., image size. This testing will use ETDRS charts. The level of central visual 
resolution is converted to a visual minimal angle of resolution score (LogMAR) for comparison 
purposes.  
Visual Field Tests: Visual field parameters will evaluate alterations in function of different 
regions of the retina; kinetic fields will be measured with Goldmann (III4e isopter), and 
Humphrey static fields with computerized testing, including foveal and macular thresholds, and 
a central field. In addition, Octopus kinetic perimetry will be done to subjects whose central 

 
 
 
 
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visual field is >20° in at least 1 of the 24 meridians at Screening/Baseline visit using Goldmann 
perimetry III4e isopter. 
Reading speed: The reading speed test will require subjects to read designated word charts with 
black letters on a white background aloud and subsequently, the critical print size and optimal 
reading speed will be calculated.  
 
Contrast Sensitivity: Contrast sensitivity will measure the subject’s ability to discern targets 
presented at varying levels of contrast.  
Color Vision Test: Color vision testing will be conducted if the subjects are able to perceive the 
test objects. 
 
Microperimetry: Microperimetry will be conducted in the dark-adapted state to evaluate 
maximal retinal sensitivity. Microperimetry measurements of the injected eyes will also be 
compared to the control (uninjected) eyes. Microperimetry will measure minimal detectable 
stimulus, mean sensitivity, and visual field size. 
 
Full-field Light Sensitivity Threshold Testing: Full-field light sensitivity threshold (FST) 
testing measures the light sensitivity of the entire visual field by recording the luminance at 
which a subject reports seeing the dimmest flash. The test is carried out on subjects with dilated 
eyes in a dark-adapted state; subjects are seated in front of a Ganzfeld dome in which the light 
flashes are generated. The light sensitivity of each eye is measured separately by removing 
patches from one eye (and then the other). A sound is generated at the time of the light flash 
and the subject presses one button when they see a flash or a second button if they do not see a 
flash. Flashes of varying luminance (in a range spanning ~80 dB) are presented in a 
randomized order, except that the series starts with dim flashes. From this data, an algorithm 
calculates the minimum luminance (for each eye) at which the subject perceives light. 
Fundus Photography: Fundoscopy will be performed with indirect ophthalmoscopic exam and 
fundus biomicroscopy. Photographs will be taken with a fundus camera following standard 
clinical methods. 
Optical coherence tomography (OCT): OCT captures micrometer-resolution, three-dimensional 
images from within optical scattering media (e.g., retinal tissue). The Heidelberg Spectralis 
OCT machine will be used. Optical coherence tomography is an interferometric technique, 
typically employing near-infrared light. The use of relatively long wavelength light allows it to 
penetrate into the scattering medium, providing important images, including the thickness of 
the retina. 
Quality of Life questionnaire: The Investigators will use a QOL questionnaire relevant to the 
subject population.  
5.3 Safety Evaluations 
Safety will be monitored and data captured by description of adverse events and pregnancy 
outcomes in female partners of subjects post vector administration. Adverse events will be 
reported to the regulatory agencies that oversee gene therapy trials, including the Sponsor, local 

 
 
 
 
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A qualified pharmacist with specific training on this protocol will be responsible for vector 
receipt from the Sponsor, storage, documentation of traceability of investigational product at 
the investigational site, and preparation (dilution) on the day of surgery. Prior to dispensing of 
the investigational product from the investigational pharmacy for administration to a study 
subject, a Pharmacy Order Form shall be completed and signed by a Principal Investigator or 
qualified Sub-Investigator. This form is to be completed on a subject-by-subject basis; the 
Investigators should complete and initial the date and time section. Upon receiving the order 
form, the investigational pharmacy will prepare the investigational product as follows:  
Universal precautions and appropriate personal protective equipment will be used by 
investigational pharmacy personnel performing the dilution. The frozen AAV2-hCHM and 
diluent vials shall be thawed at room temperature and gently mixed. Appropriate volumes of 
the AAV2-hCHM and diluent products, both provided by the Sponsor, will then be combined 
using aseptic techniques in a biosafety cabinet. The Sponsor’s instructions for this procedure, 
including the specific volumes of AAV2-hCHM and diluent to combine, will accompany each 
individual lot of material delivered to the investigational pharmacy. 
7.2 Labeling 
The product label indicates: Investigational product name (AAV2-hCHM); manufacturer 
(CCMT CVC, Children’s Hospital of Philadelphia PA, USA); specific lot number; date of 
manufacture; vial number; storage instructions (< 60°C); and investigational product warning 
(Caution: New Drug – Limited by Federal Law to Investigational Use).   
7.3 Dosing 
The two doses of AAV2-hCHM proposed for this study are: Up to 5x1010 vg per eye (Dose 
Group 1) and up to 1x1011 vg per eye (Dose Group 2). Dosing was based on several 
considerations. In vitro non-clinical data demonstrated robust REP-1 protein levels and 
normalization of prenylation activity as well as restoration of Rab27 intravesicular transport to 
the cell membrane (see section 1.4.1) at doses comparable to those used in the RPE65 non-
clinical studies, without toxicity in mice (Vasireddy et al., 2013). Additionally, the data from 
the prior Phase 1, the Phase 1 follow-on, and the Phase 3 studies for RPE65 mutations support 
safety in the dose range of 1.5x1010 to 1.5x1011 vg/eye. Because choroideremia results in 
progressive death of peripheral retina, some subjects enrolled in this study may not have 
enough viable retina to tolerate an injection volume of 300 µL. In such instances, the maximum 
volume of the given vector concentration will be injected and the volume will be recorded, to 
calculate the exact dose administered. The study in the UK of an AAV2 vector delivering REP-
1 via an AAV2 vector to patients with choroideremia also supports the proposed doses. The 
UK starting dose was 1x1010 vg/eye in 100 µL, tailored to the area of intact retinal cells 
(MacLaren et al., 2014); this study has progressed to a dose of 1x1011 vg/eye, with no reports 
of vector-related toxicity (MacLaren, Choroideremia Research Foundation Meeting, June 15-
17, 2014, Denver).  
Subjects who enroll and are eligible but not injected may be replaced with another eligible 
subject to achieve up to 15 injected, evaluable subjects. There will be a minimum two-week 
interval between subject injections. This interval is based on the accumulated safety data of the 
RPE65 clinical trials. There may be adverse events beyond the first two weeks, but these 
generally are complications of those adverse events arising in the first two weeks post-

 
 
 
 
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administration. Barring possible or probable vector-related dose limiting toxicity in one of the 
dosage groups, it is anticipated that a total of 15 evaluable, injected subjects will be entered on 
study. 
7.4 Stopping Rules 
The toxicity criteria are based on the WHO toxicity scale, with added assessments pertaining to 
ocular AEs (located in the Manual of Procedures). Dose-limiting toxicity (DLT) will be defined 
as any irreversible Grade 3 or higher toxicity, or any reversible Grade 4 toxicity, that is 
possibly or probably related to AAV2-hCHM. Irreversible toxicities are defined as those that 
persist at the same (or higher) grade for more than seven days; reversible toxicities are those 
resolving in seven or fewer days.  
If DLT is experienced, further subject enrollment will be delayed pending consultation with the 
DSMB. If a subject experiences any DLT, the DSMB will assist in determining whether 
additional subjects should be enrolled at the same dose level, or at a lower dose level. If two 
subjects of a dose group develop limiting toxicity, possibly or probably attributable to the 
vector, the maximum tolerated dose (MTD) will have been reached. In the event this occurs in 
Dose Group 2, additional subjects may be enrolled to the group just below the MTD, i.e. Dose 
Group 1.  
If a single occurrence of Grade 4 toxicity, excluding toxicities covered under the category 
“General”, or death of a subject occurs and is deemed possibly or probably related to the 
AAV2-hCHM, the Sponsor will halt enrollment and notify the DSMB and FDA. Further 
enrollment and/or vector administrations will be conducted only after FDA and the Sponsor 
confer to determine that the IND is not on clinical hold, and the DSMB agrees to continue 
enrollment. Study visits for subjects that have already received AAV2-hCHM will continue per 
protocol. 
The Sponsor or designee will report all SAEs and AEs to the DSMB, FDA, NIH OBA, and to 
Principal Investigators (who will in turn notify the IRBs/Institutional Ethics Committees (IECs) 
of record) within the required reporting timeframes. In addition to the stopping rules outlined 
above and based on the toxicity criteria table (located in the Manual of Procedures), the 
Sponsor will respond to recommendations of the DSMB.  
7.5 Compliance and Adherence 
Following the subretinal administration of AAV2-hCHM, subjects will be followed according 
to the protocol schedule of evaluations. Subjects will be encouraged to follow-up completely 
and according to the study endpoints. Non-adherence to the protocol will be reported to the 
relevant regulatory groups overseeing the study.  
7.6 Accountability 
Adequate records of investigational product receipt and disposition will be maintained by the 
investigational Pharmacy, and records of receipts, investigational drug orders, dispensing 
records, and disposition forms will be examined during the course of the study. The purpose of 
these records is to ensure the regulatory authorities and the Sponsor that the investigational new 
drug will not be distributed to any person who is not a study subject under the terms and 
conditions set forth in this protocol. The investigational product is to be prescribed by the 

 
 
 
 
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Investigators or qualified designee and may not be used for any purpose other than that 
described in the protocol. At study completion, all investigational product supplies including 
partially used and empty containers must be destroyed or returned to the Sponsor, or designee, 
per their instructions. 
8  SAFETY MANAGEMENT 
8.1 Clinical Adverse Events 
All adverse events will be monitored throughout the active and long-term follow-up phase 
following vector administration. Adverse event inquiry and assessment will be conducted on an 
ongoing basis during study participation through the following means: 
• 
Subject inquiry or report 
• 
Physical observation and/or physical examination 
• 
Laboratory and any other diagnostic test results review 
• 
Telephone call 
• 
E-mail 
• 
Postal query 
The toxicity reporting scale (located in the Manual of Procedures) should be used, when 
possible, to assess adverse events. 
8.2 Adverse Event Reporting 
All events described by the subject will be reported as AEs, regardless of toxicity grade in.  
Protocol-defined safety laboratory test results will be collected prospectively and analyzed 
separately as part of the study. Additional laboratory test results at other time points may be 
available to the Investigators as part of standard clinical practice. Throughout the active phase 
of the study, laboratory-related abnormalities should be recorded as AEs only if considered 
clinically significant, outside the range of expected values given the subject’s baseline 
assessments and clinical course, and not known to be part of another AE diagnosis. As per 
regulatory guidelines, pre-existing conditions, including abnormal lab values manifest at 
baseline testing, will only be reported as adverse events if the condition worsens in severity 
and/or frequency.  
The Investigators will follow an AE until the event is either resolved or assessed as stable. 
The Investigators are responsible for notifying the Sponsor representative or designee and the 
IRB of all AEs and other unanticipated problems related to research. Unanticipated problems 
are other types of incidents, experiences, and outcomes that occur during the conduct of human 
subject research that are not considered adverse events. For example, some unanticipated 
problems involve social or economic harm instead of the physical or psychological harm 
associated with adverse events. In other cases, unanticipated problems place subjects or others 
at increased risk of harm, but no harm occurs.   

 
 
 
 
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The Sponsor or designee will notify the appropriate federal regulatory authorities (FDA, NIH 
OBA, DSMB). Events that do not require expedited reporting will be summarized at the time 
of continuing review / annual report.  
 
8.3 Definition of an Adverse Event 
An adverse event (AE) is any untoward, undesired, or unplanned clinical event in the form of 
signs, symptoms, disease, or laboratory or physiological observations occurring in a subject 
participating in a clinical study with the Sponsor's investigational product, regardless of causal 
relationship.  Adverse events will include any conditions that: 1) were not present prior to 
investigational product administration, but appeared following investigational product 
administration; or 2) were present prior to investigational product administration, but worsened 
in severity and/or frequency following investigational product administration. 
Adverse events will be noted in the study records and on the case report form with a full 
description including the nature, date of onset (as well as time, if feasible), determination of 
non-serious versus serious, intensity (mild, moderate, severe, life-threatening, death), duration 
(i.e. end date and time, if feasible), causality, and outcome of the event. 
Suspected adverse reaction (SAR) means any adverse event for which there is a reasonable 
possibility that the drug caused the adverse event. For the purposes of IND safety reporting, 
reasonable possibility means there is evidence to suggest a causal relationship between the 
intervention and the adverse event. Suspected adverse reaction implies a lesser degree of 
certainty than adverse reaction, which means any adverse event caused by a drug. Suspected 
adverse reactions are the subset of all AEs for which there is a reasonable possibility that the 
drug caused the event. Inherent in this definition, and in the requirement to report them is the 
need for the sponsor to evaluate the available evidence and make a judgment about the 
likelihood that the drug actually caused the adverse event. 
An AE or SAR is considered unexpected if it is not listed in the Investigator’s Brochure or is 
not listed at the specificity or severity that has been observed.    
8.4 Definition of a Serious Adverse Event (SAE) 
An AE or SAR is considered serious if, in the view of either the Investigator or Sponsor, it 
results in any of the following outcomes:  
• 
Death; 
• 
A life-threatening event (its occurrence places the subject at immediate risk of 
death);  
• 
Inpatient hospitalization or prolongation of existing hospitalization; 
• 
A persistent or significant incapacity or substantial disruption of the ability to 
conduct normal life functions; or 
• 
A congenital anomaly/birth defect.   
Important medical events that may not result in death, be life-threatening, or require 
hospitalization may be considered serious when, based upon appropriate medical judgment, 

 
 
 
 
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they may jeopardize the subject and may require medical or surgical intervention to prevent 
one of the outcomes listed in this definition.  
A prescheduled, elective procedure, or a routinely scheduled treatment that requires 
hospitalization is NOT considered as to be an SAE; the study site must document all of the 
following: 
• The prescheduled, or elective procedure, or routinely scheduled treatment was scheduled 
(or was on a waiting list to be scheduled) prior to obtaining the subject’s consent to 
participate in the study. 
• The condition requiring the prescheduled, or elective procedure, or routinely scheduled 
treatment was present before and did not worsen or progress, in the opinion of the 
Investigator, between the subject’s consent to participate in the study and the time of the 
procedure or treatment. The prescheduled, or elective procedure, or routinely scheduled 
treatment is the sole reason for the intervention or hospital admission. 
A distinction should be drawn between serious and severe events or reactions. A severe 
AE/SAR is a major event of its type. A severe AE/SAR does not necessarily need to be 
considered serious. For example, nausea which persists for several hours may be considered 
severe nausea, but would not be considered serious. On the other hand, a stroke that results in 
only a limited degree of disability may be considered a mild stroke, but would be considered 
serious.  
If there is any doubt whether an AE qualifies as an SAE based on the definitions above, the 
Investigator should contact the Sponsor. 
8.5 Grading of Adverse Events 
Adverse events will be graded for intensity as mild, moderate, severe, life-threatening, or 
resulting in death as defined below. If applicable, the toxicity grade found in the Manual of 
Procedures should also be noted.   
Grade 
Description 
Mild 
Symptom barely noticeable to the subject and does not influence his/her performance 
or functioning. 
Moderate 
Symptom of a sufficient severity to make the subject uncomfortable or hinder the 
performance of daily activities; treatment of symptom may be needed.   
Severe 
Symptom causes severe discomfort; treatment for symptom may be given and/or 
subject may be hospitalized. 
Life-
threatening  
Occurrence of the event places the subject at immediate risk of death. 
Death 
Occurrence of the event results in the death of the subject.  

 
 
 
 
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8.6 Relationship to the Investigational Product  
The Investigator will document his/her opinion of the relationship of each AE to the vector 
administration procedure, investigational product, and study measures using the criteria 
outlined below. Relationship to the administration procedure should also be noted.  
Relationship 
Description 
Unlikely to 
be related 
AEs which, after careful medical consideration at the time they are evaluated, are 
judged to be unrelated to the investigational material because: 
a) AE does not follow a reasonable temporal sequence or known pattern of response 
after administration of the investigational material 
b) AE could readily have been produced by the subject’s clinical state, environmental 
or toxic factors, or other modes of therapy administered to the subject. 
Possibly 
related 
 
AEs for which, after careful medical consideration at the time they are evaluated, a 
connection with the investigational material appears unlikely but cannot be ruled out 
with certainty, because at least one of the following criteria are met: 
a) AE follows a reasonable temporal sequence or known pattern of response after 
administration of investigational material.  
b) AE could not readily have been produced by subject’s clinical state, toxic or 
environmental factors or other modes of therapy administered to the subject.   
Probably 
related 
AEs which, after careful medical consideration at the time they are evaluated, are felt 
with a high degree of certainty to be related to the investigational material, because the 
following criteria are met: 
a) AE cannot be reasonably explained by the known characteristics of the subject’s 
clinical state or by environmental or toxic factors; 
and at least one of the following is true:  
b) AE follows a reasonable temporal sequence from administration of the 
investigational new drug and/or administration procedure;  
c) AE follows a known pattern of response to the investigational new drug or 
administration procedure;  
d) AE disappears or decreases on cessation or reduction in activity of the 
investigational new drug; or 
e) AE reappears upon re-challenge or re-administration of the investigational new 
drug. 
Investigators are responsible for reporting SAEs and suspected unexpected serious adverse 
reactions (i.e., SUSARs) to their respective Independent Reviewing Authorities (IRAs; may 

 
 
 
 
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• Whenever possible, the AE should be evaluated and reported as a diagnosis rather 
than as individual signs or symptoms. If a definitive diagnosis is not possible, the 
individual signs and symptoms should be recorded. 
• If an AE requires a surgical or diagnostic procedure, the illness leading to the 
procedure should be recorded as the AE, not the procedure itself. 
For SAEs, the initial notification should include all available information requested on the SAE 
Form; the initial notification must be followed by written documentation, which includes all 
information including causality assessment from the Principle Investigator. The SAE Form will 
collect data surrounding the event, e.g., the nature of the symptom(s), time of onset in relation 
to initiation of investigational product, duration, severity, and whether or not treatment was 
administered for the symptoms experienced. The Investigator’s assessment of the probable 
cause of the event will also be included. A physician will examine subjects who experience an 
SAE or a medical emergency situation as soon as possible. The physician in attendance will do 
whatever is medically necessary for the safety and well-being of the subject. The subject will 
remain under observation as long as medically indicated in the opinion of the Investigator. 
Appropriate lab studies will be conducted until all parameters return to normal or are otherwise 
explained. The SAE will be followed until resolved or until medically stabilized. In a medical 
emergency requiring immediate attention, study site staff will provide appropriate medical 
care, according to current standards of care.  The Investigator or his/her designee should 
contact the Sponsor or designee Medical Monitor. The Sponsor or designee will notify the 
appropriate federal regulatory authorities.  
If an SAE has not resolved at the time of the initial report, a follow-up report including all 
relevant new or reassessed information (e.g., concomitant medication, medical history) should 
be submitted to the Sponsor or designee. All SAEs should be followed until either resolved or 
stable. The Medical Monitor and the independent DSMB will review all AEs. 
Investigator safety reports must be prepared for suspected unexpected serious adverse reactions 
(SUSARs) according to local regulatory requirements and Sponsor policy, and forwarded to 
Investigators as necessary. An Investigator who receives an investigator safety report 
describing an SAE or who receives other specific safety information (e.g., summary or listing 
of SAEs) from the Sponsor will review and then file it along with the Investigator’s Brochure 
and will notify the IRB/IEC if appropriate according to local regulatory reporting requirements. 
8.9 Reporting of Partner Pregnancy Occurrences and Outcomes 
Should a female partner of a subject become pregnant after the subject has been administered 
AAV2-hCHM, the subject will inform the Investigator as soon as possible. The Investigator 
will obtain the consent and authorization of medical information release from subject’s female 
partner before following up with the subject and/or subject’s female partner to obtain the 
eventual outcome of the pregnancy. Other information related to the pregnancy may be 
requested for safety reporting purposes. This information will be tracked by the Sponsor or its 
designee. 

 
 
 
 
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• If a partner pregnancy occurrence is reported, the Investigator should inform the 
Sponsor or its designee within 5 business days of learning of the pregnancy 
occurrence. 
• The Investigator should follow up with the subject and/or subject’s female partner at 
the expected time to obtain the pregnancy outcome. 
• The Investigator should inform the Sponsor or its designee within 5 business days 
of learning of the pregnancy outcome. 
• Abnormal pregnancy outcomes including but not limited to spontaneous abortion, 
fetal death, stillbirth, congenital anomalies, and ectopic pregnancy are considered 
SAEs. 
• Pregnancy information for female partners of subjects if the female partners were 
already known to be pregnant at the time of AAV2-hCHM administrations should 
be collected as medical history. 
9 STUDY ADMINISTRATION 
9.1 Dose Group Assignment Methods 
This is an open-label, non-randomized, non-blinded inter-group dose escalation safety and 
tolerability study of AAV2-hCHM, administered unilaterally by single subretinal vector 
delivery. Barring toxicity, subjects will be sequentially entered to Dose Group 1, then Dose 
Group 2.    
9.2 Data Collection and Management 
Complete and accurate records are essential for the performance of a clinical trial and accurate 
interpretation of its results. These records will be maintained in a secure area with limited 
access, but will be available and attainable for audits as required by federal, local, or 
institutional regulatory agencies. All trial registration documents will be obtained and pass a 
compliance review before shipment of investigational drug to a study site will be authorized by 
the Sponsor.  
The investigative team is responsible for maintaining a comprehensive and centralized filing 
system of all relevant study documentation including: 
• Case report forms 
• Subject source document files  
• Monitoring logs  
• Registration documents (including Clinical Protocol and Investigator’s Brochure, 
curriculum vitae of participating Investigators, IRB correspondence, signed 1572) 
• Drug accountability records  
Data will be entered from subject source documents to Case Report Forms that are specially 
designed for this study. The Investigators are responsible for accurate completion of these 
forms for all subjects who receive AAV2-hCHM in the study. These forms are an integral part 
of the study and must be completed.  

 
 
 
 
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All data and records generated during this study will be kept confidential in accordance with 
institutional policies and Health Insurance Portability and Accountability Act (HIPAA) on 
subject privacy. Investigators and other site personnel will not use the data and records for any 
purpose other than conducting the study. Study subjects should be identified on Case Report 
Forms by study number, not by name or initials, to protect subject privacy. The Investigators 
will keep a separate log of subject names and addresses in a locked cabinet and/or on a separate 
computer as a password protected file. However, in compliance with FDA Good Clinical 
Practice regulations, the study monitor may review that portion of the subject's medical record 
that is directly related to the study.  
All trial Essential Documents will be retained in the study site files for a minimum of two years 
after the date of approval for commercial license of a biologic, device, or drug, last approval of 
a marketing application in an ICH region, until there are no pending or contemplated marketing 
applications in an ICH region, or until at least two years have elapsed since the formal 
discontinuation of clinical development of the investigational material.  
9.3 Subject Confidentiality 
All data and records generated during this study will be kept confidential in accordance with 
Institutional policies and HIPAA on subject privacy, and Investigators and other site personnel 
will not use such data and records for any purpose other than conducting the study. The 
safeguards to maintain subject confidentiality include training all study personnel in HIPAA 
guidelines for study privacy and security. Subject specimens will be coded according to the 
designation provided by the master subject list.  
9.4 Regulatory and Ethical Considerations 
9.4.1 Data and Safety Monitoring Plan 
The Sponsor will follow a Data and Safety Monitoring Plan for this study. The study sites will 
be monitored by an independent contract research organization for compliance with FDA 
regulations and ICH Good Clinical Practice by qualified and trained personnel. In addition, 
FDA may audit the clinical study sites and records for regulatory compliance. The Principal 
Investigators and staff are expected to cooperate and provide all relevant study documentation 
upon request for review by the auditors. All Investigators, including those responsible for 
administration and/or clinical follow-up evaluations, will be instructed in Good Clinical 
Practice (GCP) Guidelines and clinical protocol requirements.  
An independent DSMB will be established. This board will provide oversight and monitoring 
of the conduct of the trial to ensure the safety of participants and the validity and integrity of 
the data. Members of the DSMB will include clinicians, scientists, and public representatives. 
These individuals will be selected on the basis of their experience, knowledge of clinical trial 
methodology, and absence of conflicts of interest. The DSMB will review and approve the 
research protocols and detailed plans for data and safety monitoring. It will establish specific 
guidelines for monitoring for safety and review interim outcome data for safety and efficacy. 
The DSMB will also review trial performance information such as subject recruitment and 
retention, clinical site performance, and proposals for ancillary studies. It will also review 
published reports of related studies to determine whether this study needs to be changed or 
terminated. DSMB meetings, in person or by teleconference, will occur no less frequently than 

 
 
 
 
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annually while subjects are actively enrolling in the study. Following each DSMB meeting, the 
DSMB will provide the study leaders with written recommendations related to continuing, 
changing, or terminating the trial.  
Prior to implementation, any amendments to the protocol that have subject safety implications 
must be approved by the IRB and DSMB, and submitted to the IND on file with FDA. 
Measures that are critical for subject safety may be implemented simultaneously with reporting 
to the IRB, DSMB, and FDA. Any manuscript, abstract, or presentation will be available to all 
the Investigators involved in this study, as well as the DSMB as described above, for review 
prior to submission. 
9.4.2 Risk Assessment 
Clinical experience of gene therapy for the eye has been based on AAV gene delivery for 
RPE65 mutations, using the AAV2-hRPE65v2 vector. Possible adverse events for subjects 
enrolled in this study include: risks associated with the administration procedure (subretinal 
delivery) and risks associated with the investigational material (AAV2-hCHM).  
Risks associated with the administration procedure (subretinal delivery) 
• Cataract including cataract subcapsular and cataract nuclear;  
• Conjunctival hemorrhage; 
• Eye pain; 
• Diplopia; 
• Eye irritation; 
• Posterior capsule opacification;  
• suture related complication;   
• Intraocular pressure increased; 
• Corneal disorder; 
• Corneal epithelium defect; 
• Dellen (localized dehydration of the cornea); 
• Eye pruritis; 
• Macular hole; 
• Macular cyst; 
• Visual acuity reduced; 
• Headache. 
Additional potential risk, not listed above, that have been associated with the administration 
procedure and investigational material in the AAV2-hRPE65v2 studies are: 
• Retinal tear and retinal detachment 
• Ocular inflammation or infection 
• Macular disorders 
• Vitreous opacities  
A small scar at the retinotomy site is expected, as part of the healing process post-surgery. The 
scar results from penetration of the retina with the subretinal injection cannula and the 
subsequent apposition of the cannula against the underlying RPE. Since the postnatal retina is 

 
 
 
 
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terminally differentiated, cells do not divide to replace those that are damaged by retinal 
penetration. Instead, glial cells fill in the neural retinal penetration site and RPE cells directly 
underlying this site can migrate towards the retina. The net result of these changes is that the 
boundaries of the different tissue layers are maintained. The retinotomy site will result in a 
blind spot smaller than the physiologic blind spot resulting from the presence of the optic disc 
and, indeed is not detectable with standard visual field testing; it will not involve the central 
portion of the macula. It is highly unlikely that the subject will be aware of this blind spot or 
that it will have a negative impact on visual function as neither global retinal function nor 
visual acuity (function of the macula/fovea) is affected by the retinotomy scar. It would require 
sophisticated visual field analysis in a person with good vision to detect a decrease in retinal 
function after retinotomy in this point location. The retinotomy scar is not expected to cause 
diminished vision in subjects participating in this trial. 
Other expected AE would be those related to surgery, including post-operative inflammation 
such as corneal edema or abrasion, mild anterior chamber reaction (cell and flare), mild lens 
opacity (“feathering”), change in eye pressure, diplopia, mild choroidal edema, and retinal 
edema or hemorrhage at the site of injection. The symptoms, if any, would be blurred vision, 
photophobia, lacrimation and iritis-type eye discomfort. These are treatable by cycloplegia 
(atropine drops), anti-inflammatory medication with medicine administered locally (eye drops 
or injection) or systemically (steroidal or non-steroidal).  
In the clinical and non-clinical studies done to date, more serious possible AE were not 
observed, including corneal decompensation with opacification, glaucoma in the treated eye, 
iris atrophy with synechiae, persistent vitreous opacification, persistent retinal detachment 
(exudative or rhegmatogenous), retinal membrane with proliferative vitreoretinopathy, optic 
atrophy, cystoid macular edema (retinal swelling), and hypotony with eventual phthisis bulbi 
(ocular atrophy). If these events occur, some would be anticipated to resolve without treatment, 
while others would require treatment. Treatment for corneal de-compensation would involve 
corneal transplant, cataract would require extraction, vitrectomy would be used to treat vitreous 
opacities, retinal reattachment procedures would be used to treat non-resolving retinal 
detachment, filtration surgery or medication could be used to treat glaucoma, infection treated 
with antibiotics, macular edema would require treatment with anti-inflammatory agents. The 
most serious AE would be intractable glaucoma or phthisis bulbi, which could lead to a blind, 
painful eye. Those conditions can be treated with a peri-ocular injection of alcohol or 
Thorazine to treat the pain or eventual enucleation, if absolutely necessary. The worst possible 
morbidity would be complete loss of vision.  
General Anesthesia Risks 
Serious but rare adverse events from general anesthesia and surgery in otherwise healthy 
individuals include seizure, coma and death.   
Risks Based on Non-Clinical Studies 
A toxicology study in non-human primates evaluating two doses of GMP-comparable AAV2-
hCHM vector (3x1011 and 7.5x1011 vg/eye) showed that the higher dose, which is 15 times 
greater than the low dose to be evaluated in this study, resulted in mild and focal loss of 
photoreceptors. These changes were observed 3 months post-injection, but not at the earlier (3 

 
 
 
 
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week) time point. Ocular histopathology at 3 weeks in both vehicle and AAV-injected eyes 
showed the predicted pathological changes due to the surgical manipulations; these included 
mild inflammatory lesions and local trauma to the RPE cells at the site of injection. 
Inflammation was present in many of the eyes, and there was a trend toward increasing 
inflammation related to the higher dose of AAV2-hCHM and the longer time to sacrifice of 
animals. On the numeric inflammatory scale used to score the changes in these eyes (from 0-4, 
with 4 being severe inflammation), there were no eyes in the study with an inflammatory score 
greater than 1. This indicates that in the eyes with the most prominent inflammatory changes, 
the inflammation was mild. 
It is not clear what the mild focal loss of photoreceptors observed in animals injected with the 
high dose of AAV2-hCHM and sacrificed at day 91 was due to. The possibilities include: 
complications of the subretinal injection, the AAV2 capsid, or expression of human REP-1 in 
cynomolgus monkeys. Since higher doses of AAV2-hRPE65 did not lead to photoreceptor loss 
when injected into the eyes of this same species of monkeys, this finding is not likely due to the 
AAV2 capsid. However, it is possible that it could be due to expression of a foreign transgene, 
as there are 18 amino acid differences between the human and Cynomolgus REP-1 proteins, 
while there is only a single amino acid difference between the human and Cynomolgus 
hRPE65 proteins. Thus, it is more likely that the hREP-1 protein will be viewed as a foreign 
antigen than hRPE65. 
Potential Risks of AAV2-hCHM  
Recombinant AAV is engineered from a non-pathogenic parvovirus that naturally infects 
humans, most likely through the respiratory tract during childhood. Prior exposure to wild-type 
AAV may contribute to the immune response and it is possible that prior AAV vector 
administration could contribute as well. While these scenarios pose the risk of immune 
responses that potentially decrease the effectiveness of vector administration, and even though 
immune reactivity has been demonstrated in the AAV trials for hemophilia, consequential 
immune reactivity has not so far been seen in this trial. Neither significant immune responses to 
either the capsid or transgene have been detected. While sequential injection of an AAV vector 
has the potential for complicating immune responses, immune responses have not been 
significant, and have not resulted in untoward effects on efficacy in this study nor in  the phase 
1 trial of AAV2-hRPE65v2, or in the follow-on trial (Maguire et al., 2008; Maguire et al., 
2009; Bennett et al., 2012). 
An immune response is not expected based on the relatively small dose of vector to be 
administered in this study, compared similarly to the dose of AAV2-hRPE65v2 used for 
inherited retinal degeneration due to autosomal-recessive RPE65 gene mutations. When 
compared to the dose of AAV2-hFIX (IND #9398, inactive) that was under study for 
hemophilia B, the maximum total dose to be administered to subjects in this eye study is 
approximately 250 times less than the total dose at which the cell-mediated responses 
(described above) in the liver trial occurred. Accordingly, the dose of AAV2-hCHM used for 
this study of choroideremia compares favorably to the dose of AAV2-hRPE65v2 used for the 
RPE65 trials, and not expected to result in immune responses that prevent efficacy or 
successful injection into the contralateral eye during follow-on studies.  
One hypothetical adverse event would be the unexpected effects of the transgene on function of 

 
 
 
 
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the central nervous system (CNS) due to transduction of ganglion cells (which send their axons 
to the brain via the optic nerve). This event is considered unlikely; however, if there was 
evidence of CNS dysfunction associated with retinal transgene expression, laser ablation or a 
complete retinectomy could be performed. This would destroy the ganglion cell axons and the 
brain would no longer be exposed to the transgene product. 
9.4.3 Potential Benefits of Trial Participation 
This is a Phase 1/2 safety, tolerability and dose escalation study of the subretinal administration 
of the AAV2-hCHM vector to subjects with choroideremia. A secondary objective is to 
measure efficacy and immune responses against AAV capsid and the transgene product. It is 
not known if the doses used in this study will be sufficient to either arrest retinal degeneration 
or improve vision in the administered subjects. Similar doses of the vector used in the RPE65 
trials demonstrated safety and efficacy. Thus, from previous clinical experience it is suspected 
that the doses of vector proposed here are likely to be safe.  
The starting dose for the trial is 5x1010 vg per eye, which is roughly equivalent to the middle 
dose previously used in the RPE65 Phase 1 trial of AAV2-hRPE65v2, and which resulted in 
efficacy in the 6 subjects who received this dose of vector. Since the current study is employing 
the same serotype but a different transgene, and the non-clinical data suggests that this may 
provide efficacy (Section 1.4), it seems reasonable to start within the dose range used in the 
RPE65 trial. Dose Group 2 (1x1011 vg per eye) is also within the dose range established in the 
RPE65 studies and is comparable to the high dose used for the RPE65 Phase 1 trial. Further, 
the Sponsor anticipates lack of toxicity at these doses, based on the non-clinical data and 
pharmacology/toxicology data in non-human primates (Section 1.4).  
Based on the earlier data from clinical trials conducted under FDA IND # 13408, and from 
other trials of inherited retinal degeneration due to autosomal-recessive RPE65 gene mutations, 
as well as the non-clinical data that are described in section 1.4, it is possible that the proposed 
starting Dose 1 of 5x1010 vg per eye has the potential to yield stabilization or improvement in 
vision in affected subjects.  
9.4.4 Risk-Benefit Assessment 
There are a number of risks associated with the proposed research study. On the basis of the 
available non-clinical and clinical data to date, the Sponsor believes the potential risks are 
balanced by the potential to gain knowledge about the disease, and a potential for direct benefit 
to the subjects. The anticipated benefit:risk ratio is at least as favorable as the alternative 
approaches, as there is no FDA approved treatment for choroideremia. In this research context, 
there may be potential risks that are unexpected or unknown. 
9.5 Recruitment Strategy 
Potential subjects will be recruited from the clinics of investigative team members, from 
ophthalmology treatment centers, as well as subjects referred from health-care providers and 
self-referred subjects via materials posted in clinicaltrials.gov. After description of the clinical 
trial design to the subject, using the study consent and other approved recruitment materials as 
educational tools, if the subject wishes to pursue the gene therapy study, the consenting process 
will ensue, and if the subject agrees to study participation, the study-mandated 

 
 
 
 
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Screening/Baseline tests will be initiated. It is expected that there are sufficient subjects who 
will meet eligibility criteria for study entry.  
9.6 Informed Consent and HIPAA Authorization 
Following study approval by the governing regulatory groups, potential subjects who have met 
initial clinical criteria are approached by a member of the investigative team to determine the 
level of interest for study enrollment. Potential subjects will generally be approached in person, 
called on the telephone, or emailed to initiate the consenting process. The study’s informed 
consent documents are used as an “educational tool” for the subjects and subjects’ female 
partners to read, and ask questions of the Investigators. The content of the informed consent 
documents follows federal regulatory requirements. The informed consent process will take 
place in a private setting, for example in a clinic or hospital room, or in a doctor’s office. Steps 
will be taken to avoid coercion or undue inducements; the subject or subject’s female partner 
will be given as much time as needed to make a decision about study enrollment and/or release 
of medical information. The consent will be signed only after the subject and/or subject’s 
female partner have had all questions answered to their satisfaction. The Investigators will 
ensure that subjects understand that participation in the study is voluntary and subjects and 
subjects’ female partners understand that authorization of medical information release is 
voluntary. Subjects will have the option to withdraw from study participation and authorization 
of medical information release can be terminated when requested. Both the subject/female 
partner and the person obtaining consent (a designated member of the investigative team) will 
sign and date the consent document, and a copy will be given to the subject/female partner. The 
study or data collection can be initiated only after consent signing. Non-English speaking 
subjects are not expected for enrollment; however, if a non-English speaking subject is 
considered for enrollment or a non-English speaking female partner is pregnant, a certified 
translated and IRB-approved consent with independent interpreter would be implemented for 
the consenting process.  
9.7 Financial Considerations of Study Participation 
There will be no payment (compensation) or gifts to subjects or families. The Sponsor will 
arrange for or provide reimbursement for travel, parking, hotels and meals to the subject and 
one companion, if necessary. The costs of the long-term follow-up will be borne by the 
Sponsor.  
10 PUBLICATION 
Upon completion of the study, the Investigators may publish the results in recognized scientific 
journals subject to the provisions of the Clinical Trial Agreement (CTA). Unless otherwise 
specified in the CTA, the following process shall occur: 
The institution and Investigators shall not publish or present data from an individual study 
center until the complete multicenter study has been presented in full or for two years after the 
termination of the multicenter study, whichever occurs first, or without written Sponsor 
approval. Subsequent publications must refer to the multicenter findings. Thereafter, if the 
Investigators expects to participate in the publication of data generated from this site, the 
institutions and Investigators shall submit reports, abstracts, manuscripts, and/or other 

 
 
 
 
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presentation materials to the Sponsor for review before submission for publication or 
presentation. The Sponsor shall have 60 days to respond with any requested revisions, 
including, without limitation, the deletion of confidential information. The Principal 
Investigators shall act in good faith upon requested revisions, except that the Principal 
Investigators shall delete any confidential information from such proposed publication. 
Any manuscript, abstract, or presentation will be available to all the Investigators involved in 
this study and the DSMB for review prior to submission. Information about the conduct and 
progress of the study is not to be discussed beyond the study teams and Sponsor 
representatives, including contract research organization and DSMB members, necessary to 
conduct the study. Study data are confidential and not to be disclosed without written Sponsor 
approval.  
 
 
 
 
 

 
 
 
 
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11 REFERENCES 
Acland, G.M., Aguirre, G.D., Ray, J., Zhang, Q., Aleman, T.S., Cideciyan, A.V.,…Bennett, J. (2001). Gene 
therapy restores vision in a canine model of childhood blindness. Nature Genetics, 28, 92-95. 
doi:10.1038/ng0501-92 
Acland, G.M., Aguirre, G.D., Bennett, J., Aleman, T.S., Cideciyan, A.V., Bennicelli, J.,…Jacobson, S.G. (2005). 
Long-term restoration of rod and cone vision by single dose rAAV-mediated gene transfer to the retina in a canine 
model of childhood blindness. Molecular Therapy: The Journal of the American Society of Gene Therapy, 12(6), 
1072-82. doi:10.1016/j.ymthe.2005.08.008 
Alexandrov, K., Horiuchi, H., Steele-Mortimer, O., Seabra, M.C., & Zerial, M. (1994). Rab escort protein-1 is a 
multifunctional protein that accompanies newly prenylated rab proteins to their target membranes. The EMBO 
Journal, 13(22), 5262-5273. 
Amado, D., Mingozzi, F., Hui, D., Bennicelli, J.L., Wei, Z., Chen, Y.,…Bennett, J. (2010). Safety and efficacy of 
subretinal readministration of a viral vector in large animals to treat congenital blindness. Science Translational 
Medicine, 2(21), 21ra16. doi:10.1126/scitranslmed.3000659 
Anand, V., Duffy, B., Yang, Z., Dejneka, N.S., Maguire, A.M., & Bennett, J. (2002). A deviant immune response 
to viral proteins and transgene product is generated on subretinal administration of adenovirus and adeno-
associated virus. Molecular Therapy: The Journal of the American Society of Gene Therapy, 5(2), 125-132. doi: 
10.1006/mthe.2002.0525 
Bainbridge, J.W.B., Smith, A.J., Barker, S.S., Robbie, S., Henderson, R., Balaggan, K.,…Ali, R.R. (2008). Effect 
of gene therapy on visual function in leber's congenital amaurosis. The New England Journal of Medicine, 
358(21), 2231-2239. doi: 10.1056/NEJMoa0802268 
Basiji, D.A., Ortyn, W.E., Liang, L., Venkatachalam, V., & Morrissey, P. (2007). Cellular image analysis and 
imaging by flow cytometry, Clinics in Laboratory Medicine, 27(3), 653-670. doi: 10.1016/j.cll.2007.05.008 
Bennett, J., Duan, D., Engelhardt, J.F., & Maguire, A.M. (1997). Real-time, noninvasive in vivo assessment of 
adeno-associated virus-mediated retinal transduction. Investigative Ophthalmology & Visual Science, 38(12), 
2857-2863. 
Bennett, J., Maguire, A.M., Cideciyan, A.V., Schnell, M., Glover, E., Anand, V.,…Jacobson, S.G. (1999). Stable 
transgene expression in rod photoreceptors after recombinant adeno-associated virus-mediated gene transfer to 
monkey retina. Proceedings of the National Academy of Sciences of the United States of America, 96(17), 9920-
9925. doi: 10.1073/pnas.96.17.9920 
Bennett, J. (2003). Immune response following intraocular delivery of recombinant viral vectors. Gene Therapy, 
10(11), 977-982. doi:10.1038/sj.gt.3302030 
Bennett, J., Ashtari, M., Wellman, J., Marshall, K.A., Cyckowski, L.L., Chung, D.C.,… Maguire, A.M. (2012). 
AAV2 gene therapy readministration in three adults with congenital blindness. Science Translational Medicine, 
4(120), 120ra15. doi: 10.1126/scitranslmed.3002865 
Bennett, J., Wellman, J., Marshall, K.A., McCague, S., Ashtari, M., DiStefano-Pappas, J.,… Maguire, A.M. 
(2016). Safety and durability of effect of contralateral-eye administration of AAV2 gene therapy in patients with 
childhood-onset blindness caused by RPE65 mutations: A follow-on phase 1 trial. Lancet (London, England), 
388(10045), 661-72. doi: 10.1016/S0140-6736(16)30371-3 
Bennicelli, J., Wright, J.F., Komaromy, A., Jacobs, J.B., Hauck, B., Zelenaia, O.,… Bennett, J. (2008). Reversal of 
blindness in animal models of leber congenital amaurosis using optimized AAV2-mediated gene transfer. 
Molecular Therapy: The Journal of the American Society of Gene Therapy, 16(3), 458-465. doi: 
10.1038/sj mt.6300389 

 
 
 
 
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Confidential 
Buchlis, G., Podsakoff, G.M., Radu, A., Hawk, S.M., Flake, A.W., Mingozzi, F.,… High, K.A. (2012). Factor IX 
expression in skeletal muscle of a severe hemophilia b patient 10 years after AAV-mediated gene transfer. Blood, 
119(13), 3038-3041. doi: 10.1182/blood-2011-09-382317 
 
Chow, D.R., Williams, G.A., Trese, M.T., Margherio, R.R., Ruby, A.J., & Ferrone, P.J. (1999). Successful closure 
of traumatic macular holes. Retina, 19(5), 405-409.  
Cideciyan, A.V., Jacobson, S.G., Beltran, W.A., Sumaroka, A., Swider, M., Simone, I.,… Aguirre, G.D. (2013). 
Human retinal gene therapy for leber congenital amaurosis shows advancing retinal degeneration despite enduring 
visual improvement. Proceedings of the National Academy of Sciences of the United States of America, 110(6), 
E517-E525. doi: 10.1073/pnas.1218933110 
Couto, L. (2016). AAV gene therapy for choroideremia: Dose determination analyses. The Association for 
Research in Vision and Ophthalmology Meeting. 
Cremers, F.P., Armstrong, S.A., Brown, M.S., & Goldstein, J.L. (1994). REP-2, a rab escort protein encoded by 
the choroideremia-like gene. The Journal of Biological Chemistry, 269(3), 2111-7. 
Dejneka, N.S., Surace, E.M., Aleman, T.S., Cideciyan, A.V., Lyubarsky, A., Savchenko, A.,… Bennett, J. (2004). 
In utero gene therapy rescues vision in a murine model of congenital blindness. Molecular Therapy: The Journal 
of the American Society of Gene Therapy, 9(2), 182-188. doi: 10.1016/j.ymthe.2003.11.013 
Donsante, A., Miller, D.G., Li, Y., Vogler, C., Brunt, E.M., Russell, D.W.,… Sands, M.S. (2007). AAV vector 
integration sites in mouse hepatocellular carcinoma. Science, 317-477. doi: 10.1126/science.1142658 
Edwards, T.L., Jolly, J.K., Groppe, M., Barnard, A.R., Cottriall, C.L., Tolmachova, T.,… MacLaren, R.E. (2016). 
Visual acuity after retinal gene therapy for choroideremia. The New England Journal of Medicine, 374(20), 1996–
1998. doi: 10.1056/NEJMc1509501 
Fighting Blindness Canada. (2012, February 15). Foundation Fighting Eye disease fact sheet: Choroideremia. 
Retrieved from 
http://www.ffb.ca/eye_conditions/choroideremia html?PHPSESSID=f7e881c77bc902024ee61fc00c2f18e5 
Genetics Home Reference. (2008, July). Choroideremia. Retrieved from 
http://ghr nlm.nih.gov/condition/choroideremia 
Graham, F.L., Smiley, J., Russell, W.C., & Nairn, R. (1977). Characteristics of a human cell line transformed by 
DNA from human adenovirus type 5. The Journal of General Virology, 36(1), 59-72. doi: 10.1099/0022-1317-36-
1-59 
 
Hauswirth, W.W., Aleman, T.S., Kaushal, S., Cideciyan, A.V., Schwartz, S.B., Wang, L.,… Jacobson, S.G. 
(2008). Treatment of leber congenital amaurosis due to RPE65 mutations by ocular subretinal injection of adeno-
associated virus gene vector: Short-term results of a phase I trial. Human Gene Therapy, 19(10), 979-90. doi: 
10.1089/hum.2008.107 
 
Ignatova, I. (2016). AAV gene therapy for choroideremia: Dose determination analyses. American Society of Gene 
& Cell Therapy Meeting. 
Jacobs, J.B., Dell-Osso, L.F., Hertle, R.W., Acland, G.M., & Bennett, J. (2006). Eye movement recordings as an 
effectiveness indicator of gene therapy in RPE65-deficient canines: Implications for the ocular motility system. 
Investigative Ophthalmology & Visual Science, 47(7), 2865-2875. doi: 10.1167/iovs.05-1233 
Jacobson, S.G., Aleman, T.S., Cideciyan, A.V., Sumaroka, A., Schwartz, S.B., Windsor, E.A.M,… Bennett, J. 
(2005). Identifying photoreceptors in blind eyes caused by RPE65 mutations: Prerequisite for human gene therapy 
success. Proceedings of the National Academy of Sciences of the United States of America, 102(17), 6177-6182. 
doi: 10.1073/pnas.0500646102 

 
 
 
 
Protocol AAV2-hCHM-101     
Page 50 
 
08 Apr 2020 (Version 10) 
 
Confidential 
Jacobson, S.G., Cideciyan, A.V., Sumaroka, A., Aleman, T.S., Schwartz, S.B., Windsor, E.A.,… MacDonald, I.M. 
(2006). Remodeling of the human retina in choroideremia: Rab escort protein 1 (REP-1) mutations. Investigative 
Ophthalmology & Visual Science, 47(9), 4113-20. doi: 10.1167/iovs.06-0424 
Jacobson, S.G., Acland, G.M., Aguirre, G.D., Aleman, T.S., Schwartz, S.B., Cideciyan, A.V.,… Hauswirth, W.W. 
(2006). Safety of recombinant adeno-associated virus type 2-RPE65 vector delivered by ocular subretinal 
injection. Molecular Therapy: The Journal of the American Society of Gene Therapy, 13(6), 1074-84. doi: 
10.1016/j.ymthe.2006.03.005 
Jacobson, S.G., Boye, S.L., Aleman, T.S., Conlon, T.J., Zeiss, C.J., Roman, A.J.,…Hauswirth, W.W. (2006). 
Safety in nonhuman primates of ocular AAV2-RPE65, a candidate treatment for blindness in leber congenital 
amaurosis. Human Gene Therapy, 17(8), 845-858. doi: 10.1089/hum.2006.17.845 
Jacobson, S.G., Cideciyan, A.V., Ratnakaram, R., Heon, E., Schwartz, S.B., Roman, A.J.,…Hauswirth, W.W. 
(2012). Gene therapy for leber congenital amaurosis caused by RPE65 mutations: Safety and efficacy in 15 
children and adults followed up to 3 years. Archives of Ophthalmology (Chicago, III. : 1960) 130(1), 9-24. doi: 
10.1001/archophthalmol.2011.298 
Jiang, H., Pierce, G., Ozelo, M., de Paula, E., Vargas, J., Smith, P.,… Arruda, V. (2006). Evidence of multiyear 
factor IX expression by AAV-mediated gene transfer to skeletal muscle in an individual with severe hemophilia b. 
Molecular Therapy: The Journal of the American Society of Gene Therapy, 14(3), 452-455. doi: 
10.1016/j.ymthe.2006.05.004 
 
Kozak, M. (1997). Recognition of AUG and alternative initiator codons is augmented by G in position F4 but is 
not generally affected by the nucleotides in positions F5 and F6. The EMBO Journal, 16(9), 2482–2492. doi: 
10.1093/emboj/16.9.2482   
 
Li, H., Malani, N., Hamilton, S.R., Schlachterman, A., Bussadori, G., Edmonson, S.E.,… High, K.A. (2011). 
Assessing the potential for AAV vector genotoxicity in a murine model. Blood, 117(24), 3311-3319. doi: 
10.1182/blood-2010-08-302729 
MacDonald, I.M., Russell, L., Chan, C.C. (2009). Choroideremia: New findings from ocular pathology and review 
of recent literature. Survey of Ophthalmology, 54(3), 401-407. doi: 10.1016/j.survophthal.2009.02.008 
MacLaren, R. (2012). Treatment of choroideremia in humans by gene replacement. The Association for Research 
in Vision and Ophthalmology Meeting. 
MacLaren, R.E., Groppe, M., Barnard, A.R., Cottriall, C.L., Tolmachova, T., Seymour, L.,… Seabra, M.C. 
(2014). Retinal gene therapy in patients with choroideremia: initial findings from a phase 1/2 clinical trial. Lancet 
(London, England), 383(9923), 1129-1137. doi: 10.1016/S0140-6736(13)62117-0 
Maguire, A.M., Simonelli, F., Pierce, E.A., Pugh, E.N., Mingozzi, F., Bennicelli, .J,… Bennett, J. (2008). Safety 
and efficacy of gene transfer for leber congenital amaurosis. The New England Journal of Medicine, 358(21), 
2240-2248. doi: 10.1056/NEJMoa0802315 
Maguire, A.M., High, K.A., Auricchio, A., Wright , J.F., Pierce, E.A., Testa, F.,… Bennett, J. (2009). Age-
dependent effects of RPE65 gene therapy for leber's congenital amaurosis: A phase 1 dose-escalation trial. Lancet 
(London, England), 374(9701), 1597-1605. doi: 10.1016/S0140-6736(09)61836-5   
Manno, C.S., Chew, A.J., Hutchison, S., Larson, P.J., Herzog, R.W., Arruda, V.R.,… Glader, B. (2003). AAV-
mediated factor IX gene transfer to skeletal muscle in patients with severe hemophilia b. Blood, 101(8), 2963-72. 
doi: 10.1182/blood-2002-10-3296 
McCarty, D.M., Young, S.M., & Samulski, R.J. (2004). Integration of adeno-associated virus (AAV) and 
recombinant AAV vectors. Annual Review of Genetics, 38, 819-45. doi: 10.1146/annurev.genet.37.110801.143717 
McGrath, K.E., Bushnell, T.P., & Palis, J. (2008). Multispectral imaging of hematopoietic cells: Where flow 
meets morphology. Journal of Immunological Methods, 336(2), 91-97. doi: 10.1016/j.jim.2008.04.012 

 
 
 
 
Protocol AAV2-hCHM-101     
Page 51 
 
08 Apr 2020 (Version 10) 
 
Confidential 
Mingozzi, F., & High, K.A. (2011). Therapeutic in vivo gene transfer for genetic disease using AAV: Progress and 
challenges. Nature Reviews Genetics, 12(5), 341-55. doi: 10.1038/nrg2988 
Mura, M., Sereda, C., Jablonski, M.M., MacDonald, I.M., & Iannaccone, A. (2007). Clinical and functional 
findings in choroideremia due to complete deletion of the CHM gene. Archives of Ophthalmology (Chicago, III. : 
1960), 125(8), 1107-13. doi: 10.1001/archopht.125.8.1107 
Nussbaum, R.L., Lewis, R.A., Lesko, J.G., & Ferrell, R. (1985). Choroideremia is linked to the restriction 
fragment length polymorphism DXYSJ at XQ13-21. American Journal of Human Genetics, 37(3), 473-481.  
Orphanet. (n.d.) Choroideremia, OMIM 303100. Retrieved from http://www.orpha.net/consor/cgi-
bin/Disease_Search.php?lng=EN&data_id=921&Disease_Disease_Search_diseaseGroup=Choroideremia&Diseas
e_Disease_Search_diseaseType=Pat&Disease(s)/group%20of%20diseases=Choroideremia&title=Choroideremia
&search=Disease_Search_Simple 
Roberts, M.F., Fishman, G.A., Roberts, D.K., Heckenlively, J.R., Weleber, R.G., & Anderson, RJ. (2002). 
Retrospective, longitudinal, cross sectional study of visual acuity impairment in choroideraemia. The British 
Journal of Ophthalmology, 86(6), 658-62. doi: 10.1136/bjo.86.6.658 
 
Rosenberg, T., & Schwartz, M. (1994). Age differences of visual field impairment and mutation spectrum in 
Danish choroideremia patients. Acta Ophthalmology, 72(6), 678-82. doi: 10.1111/j.1755-3768.1994.tb04679.x 
 
Russell, S., Bennett, J., Wellman, J.A., Chung, D.C., Yu, Z.F., Tillman, A.,… Maguire, A.M. (2017).  Efficacy 
and safety of voretigene neparvovec (AAV2-hRPE65v2) in patients with RPE65-mediated inherited retinal 
dystrophy: A randomised, controlled, open-label, phase 3 trial. Lancet (London, England), 390(10097), 848-860. 
doi: 10.1016/S0140-6736(17)31868-8. 
 
Samulski, R.J., Berns, K.I., Tan, M., & Muzyczka, N. (1982). Cloning of adeno-associated virus into pBR322: 
Rescue of intact virus from the recombinant plasmid in human cells. Proceedings of the National Academy of 
Sciences of the United States of America, 79(6), 2077-2081. doi: 10.1073/pnas.79.6.2077 
 
Samulski, R. J., Chang, L.S., & Shenk, T. (1987). A recombinant plasmid from which an infectious adeno-
associated virus genome can be excised in vitro and its use to study viral replication. Journal of Virology, 61(10), 
3096-3101.  
Seabra, M.C., Brown, M.S., & Goldstein, J.L. (1993). Retinal degeneration in choroideremia: Deficiency of rab 
geranylgeranyl transferase. Science (New York, N.Y.), 259(5093), 377-381. doi: 10.1126/science.8380507 
Seabra, M.C., Ho, Y.K., & Anant, J.S. (1995).  Deficient geranylgeranylation of Ram/Rab27 in choroideremia. 
The Journal of Biological Chemistry, 270(41), 24420-24427. doi: 10.1074/jbc.270.41.24420 
Simonelli, F., Maguire, A.M., Testa, F., Pierce, E.A., Mingozzi, F., Bennicelli, JL,… Auricchio, A. (2010). Gene 
therapy for leber’s congenital amaurosis is safe and effective through 1.5 years after vector administration. 
Molecular Therapy: The Journal of the American Society of Gene Therapy, 18(3), 643-650. doi: 
10.1038/mt.2009.277 
Streilein, J.W., Niederkorn, J.Y., & Shadduck, J.A. (1980). Systemic immune unresponsiveness induced in adult 
mice by anterior chamber presentation of minor histocompatibility antigens. Journal of Experimental Medicine, 
152(4), 1121-1125. doi: 10.1084/jem.152.4.1121 
Tolmachova, T., Anders, R., Abrink, M., Bugeon, L., Dallman, M.J., Futter, C.E.,… Seabra, M.C. (2006). 
Independent degeneration of photoreceptors and retinal pigment epithelium in conditional knockout mouse models 
of choroideremia. The Journal of Clinical Investigation, 116(2), 386-394. doi: 10.1172/JCI26617 
Tolmachova, T., Tolmachov, O.E., Wavre-Shapton, S.T., Tracey-White, D., Futter, C.E., & Seabra, M.C. (2012). 
CHM/REP1 cDNA delivery by lentiviral vectors provides functional expression of the transgene in the retinal 
pigment epithelium of choroideremia mice. The Journal of Gene Medicine, 14(3), 158-168. doi: 10.1002/jgm.1652 

 
 
 
 
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08 Apr 2020 (Version 10) 
 
Confidential 
Vandenberghe, L.H., Bell, P., Maguire, A.M., Cearley, C.N., Xiao, R., Calcedo, R.,… Bennett, J. (2011). Dosage 
thresholds for AAV2 and AAV8 photoreceptor gene therapy in monkey. Science Translational Medicine, 3(88), 
88ra54. doi: 10.1126/scitranslmed.3002103 
van den Hurk, J.A., Hendriks, W., van de Pol, D.J., Oerlemans, F., Jaissle, G., Rüther, K.,… Cremers, F. (1997). 
Mouse choroideremia gene mutation causes photoreceptor cell degeneration and is not transmitted through the 
female germline. Human Molecular Genetics, 6(6), 851-858. doi: 10.1093/hmg/6.6.851 
Vasireddy, V, Mill, J.A., Gaddameedi, R., Basner-Tschakarjan, E., Kohnke, M., Black, A.D.,… Bennett J. (2013). 
AAV-mediated gene therapy for choroideremia: Preclinical studies in personalized models. PLOS ONE, 8(5), 
e61396. doi: 10.1371/journal.pone.0061396 
Weckerle, P. (2009). Choroideremia. In Encyclopedia of Molecular Mechanisms of Disease. Retrieved from 
http://books.google.com/books?id=DdBJ6jCf8KgC&pg=PA349&dq=Encyclopedia+of+Molecular+Mechanisms+
of+Disease,+choroideremia;&hl=en&sa=X&ei=sEvKUfrdNYeG0QHQsIH4Bg&ved=0CC8Q6AEwAA#v=onepa
ge&q=Encyclopedia%20of%20Molecular%20Mechanisms%20of%20Disease%2C%20choroideremia%3B&f=fal
se 
Wright, J.F. (2008). Manufacturing and characterizing AAV-based vectors for use in clinical studies. Gene 
Therapy, 15(11), 840-848. doi: 10.1038/gt.2008.65 
Wright, J.F., Wellman, J., & High, K.A. (2010). Manufacturing and regulatory strategies for clinical AAV2-
hRPE65. 2010. Current Gene Therapy, 10(5), 341-349. doi: 10.2174/156652310793180715 
Wright, J.F, & Zelenaia, O. (2011). Vector characterization methods for quality control testing of recombinant 
adeno-associated viruses. Methods in Molecular Biology, 737, 247-278. doi: 10.1007/978-1-61779-095-9_11
 
 
 
 
 
 
 
 
 
 

 
 
 
 
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INVESTIGATOR’S STATEMENT 
 
INVESTIGATOR STATEMENT 
I have read the protocol, including all appendices, and I agree that it contains all of 
the necessary information for me and my staff to conduct this study as described. I 
will conduct this study as outlined herein, in accordance with Good Clinical 
Practice: Consolidated Guideline approved by the International Conference on 
Harmonization (ICH), National Institute of Health (NIH) Guidelines for Research 
Involving Recombinant or Synthetic Nucleic Acid Molecules (NIH Guidelines) April 
2016 and all applicable local and federal regulatory requirements and will make a 
reasonable effort to complete the study within the time designated. 
I will provide all study personnel under my supervision copies of the protocol and 
any amendments, and access to all information provided by Spark or specified 
designees. I will discuss the material with them to ensure that they are fully 
informed about the study. 
 
 
 
 
Principal Investigator (signature) 
 
 
 
Date (dd-MMM-yyyy) 
 
 
Principal Investigator Name (printed)  
 
 
Site Number