Conditions: Diabetic Retinopathy
Keywords: CCR3 inhibition Diabetic Retinopathy Oral Treatment
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 3
Healthy volunteers: no

Brief summary:
A Double-Masked, Placebo-Controlled Study to Evaluate the Efficacy of Oral AKST4290 in Participants with Moderately Severe to Severe Diabetic Retinopathy (CAPRI).

Detailed description:
This study is designed to evaluate the efficacy of AKST4290 administered at a total daily dose (TDD) of 800 mg daily (400 mg twice daily \[b.i.d.\]) compared with placebo over a 24-week dosing period in participants with moderately severe non-proliferative diabetic retinopathy (NPDR) to severe NPDR.

Participants will be enrolled and allocated to 1 of 2 treatment arms in a 2:1 randomization scheme (AKST4290: placebo). Participants will receive treatment for a total of 24 weeks with either AKST4290 800 mg daily (400 mg b.i.d.) in Arm 1 or placebo (matching tablets) in Arm 2

Arms:
arm 1: Subjects will receive AKST4290, 400mg twice daily, for 24 weeks arm 2: Subjects will receive matching Placebo, twice daily, for 24 weeks

Interventions: intervention 1: AKST4290 intervention 2: Placebo
Intervention descriptions: intervention 1: Oral AKST4290 intervention 2: Oral Placebo

Protocol document:
Prot_000.pdf: 
 
Alkahest, Inc. 
CONFIDENTIAL/PROPRIETARY 
Page 1 of 86 
 
 
A DOUBLE-MASKED, PLACEBO-CONTROLLED STUDY TO EVALUATE THE 
EFFICACY OF ORAL AKST4290 IN PARTICIPANTS WITH MODERATELY SEVERE 
TO SEVERE DIABETIC RETINOPATHY (CAPRI) 
 
Protocol Number: 
AKST4290-231 
IND Number: 
154780 
Clinical Phase: 
2 
Sponsor: 
Alkahest, Inc. 
125 Shoreway Road, Suite D 
San Carlos, CA 94070 
Study Agent: 
AKST4290 
Indications: 
Diabetic Retinopathy (DR) 
Authorized Representative: 
 
 
 
 
 
Version Number: 
2.0 
Version Date: 
19AUG2021 
Replaces Version(s): 
1.0 
 


Protocol AKST4290-231, (Version 2.0) 
19AUG2021 
 
 
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CONFIDENTIAL/PROPRIETARY 
Page 2 of 86 
 
TABLE OF CONTENTS 
 
TABLE OF CONTENTS .................................................................................................................2 
PROTOCOL APPROVAL PAGE .................................................................................................10 
STATEMENT OF COMPLIANCE ...............................................................................................11 
SCHEMATIC OF STUDY DESIGN ............................................................................................15 
1. 
KEY ROLES ........................................................................................................................16 
1.1. 
Authorized Representative (Signatory) / Responsible Party .............................................16 
1.2. 
Study Organization ............................................................................................................16 
2. 
INTRODUCTION ................................................................................................................17 
2.1. 
 
 
 
 
 
 
 
2.3. 
Potential Risks and Benefits ..............................................................................................19 
2.3.1. 
Known Potential Risks .................................................................................................19 
2.3.2. 
Known Potential Benefits ............................................................................................20 
3. 
OBJECTIVES AND PURPOSE ..........................................................................................21 
3.1. 
Primary Objective ..............................................................................................................21 
3.2. 
Secondary Objectives.........................................................................................................21 
3.3. 
Exploratory Objectives ......................................................................................................21 
4. 
STUDY DESIGN AND ENDPOINTS ................................................................................22 
4.1. 
Description of the Study Design ........................................................................................22 
4.2. 
Study Endpoints .................................................................................................................23 
4.2.1. 
Primary Endpoint .........................................................................................................23 
4.2.2. 
Secondary Endpoints ...................................................................................................23 
4.2.3. 
Exploratory Endpoints .................................................................................................23 
5. 
STUDY ENROLLMENT AND WITHDRAWAL ..............................................................25 
5.1. 
Inclusion Criteria ...............................................................................................................25 
5.2. 
Exclusion Criteria ..............................................................................................................25 
5.3. 
Initiation of Treatment for Proliferative Diabetic Retinopathy .........................................28 
5.4. 
Initiation of Treatment for Center-involved Diabetic Macular Edema .............................29 
5.5. 
Strategies for Recruitment and Retention ..........................................................................29 
5.6. 
Participant Withdrawal ......................................................................................................29 


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5.6.1. 
Reasons for Withdrawal ...............................................................................................29 
5.6.2. 
Handling of Participant Withdrawals...........................................................................30 
5.7. 
Premature Termination or Suspension of Study ................................................................31 
6. 
STUDY AGENTS ................................................................................................................32 
6.1. 
Study Agent and Control Description ................................................................................32 
6.1.1. 
Acquisition ...................................................................................................................32 
6.1.2. 
Formulation, Appearance, Packaging, and Labeling ...................................................32 
6.1.3. 
Product Storage and Stability.......................................................................................32 
6.1.4. 
Dosing and Administration ..........................................................................................32 
6.2. 
Study Agent Accountability ...............................................................................................32 
7. 
STUDY PROCEDURES AND SCHEDULE ......................................................................34 
7.1. 
Study Procedures and Evaluations .....................................................................................34 
7.1.1. 
Study Specific Procedures ...........................................................................................34 
7.2. 
Laboratory Procedures and Evaluations ............................................................................41 
7.2.1. 
Clinical Laboratory Evaluations ..................................................................................41 
7.2.2. 
Other Tests or Procedures ............................................................................................41 
7.3. 
Study Schedule...................................................................................................................43 
7.3.1. 
Screening......................................................................................................................43 
7.3.2. 
Treatment .....................................................................................................................43 
7.3.3. 
Early Termination or Withdrawal ................................................................................43 
7.3.4. 
Study Completion and End of Study ...........................................................................43 
7.3.5. 
Schedule of Events Table .............................................................................................43 
7.4. 
Concomitant Medications ..................................................................................................44 
7.5. 
Prohibited Medications, Treatments, and Procedures........................................................44 
8. 
ASSESSMENT OF SAFETY ..............................................................................................45 
8.1. 
Specification of Safety Parameters ....................................................................................45 
8.1.1. 
Definition of Adverse Events.......................................................................................45 
8.1.2. 
Definition of Serious Adverse Events..........................................................................46 
8.2. 
Classification of An Adverse Event ...................................................................................47 
8.2.1. 
Severity of Event..........................................................................................................47 
8.2.2. 
Relationship to Study Agent ........................................................................................48 


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CONFIDENTIAL/PROPRIETARY 
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8.2.3. 
Expectedness ................................................................................................................48 
8.3. 
Time Period/Frequency for Event Assessment/Follow-up ................................................49 
8.3.1. 
Post-Study Adverse Event and Serious Adverse Event ...............................................49 
8.4. 
Reporting Procedures .........................................................................................................49 
8.4.1. 
Adverse Event Reporting .............................................................................................49 
8.4.2. 
Serious Adverse Event Reporting ................................................................................50 
8.4.3. 
Adverse Events of Special Interest ..............................................................................52 
8.4.4. 
Reporting of Pregnancy ...............................................................................................52 
8.5. 
Study Halting Rules ...........................................................................................................52 
8.6. 
Safety Oversight.................................................................................................................52 
9. 
CLINICAL MONITORING ................................................................................................54 
10. 
STATISTICAL CONSIDERATIONS .................................................................................55 
10.1. Statistical Design Model and Analytical Plans ..................................................................55 
10.2. Statistical Hypotheses ........................................................................................................55 
10.3. Analysis Datasets ...............................................................................................................55 
10.4. Description of Statistical Methods .....................................................................................55 
10.4.1. 
General Approach ........................................................................................................55 
10.4.2. 
Analysis of the Primary Endpoint ................................................................................55 
10.4.3. 
Analysis of the Secondary Endpoints ..........................................................................56 
10.4.4. 
Analysis of the Exploratory Endpoints ........................................................................56 
10.4.5. 
Planned Interim Analyses ............................................................................................56 
10.4.6. 
Multiple Comparison/Multiplicity ...............................................................................57 
10.5. Sample Size ........................................................................................................................57 
10.6. Measures to Minimize Bias ...............................................................................................57 
10.6.1. 
Enrollment/Randomization/Masking Procedures ........................................................57 
10.6.2. 
Evaluation of the Success of Masking .........................................................................58 
10.6.3. 
Breaking the Study Mask and/or Participant Code ......................................................58 
11. 
SOURCE DOCUMENTS AND ACCESS TO SOURCE DATA/DOCUMENTS .............59 
12. 
ETHICS/PROTECTION OF HUMAN SUBJECTS ............................................................60 
12.1. Ethical Standard .................................................................................................................60 
12.2. Institutional Review Board ................................................................................................60 
12.3. Informed Consent Process .................................................................................................60 
12.3.1. 
Consent Forms .............................................................................................................60 
12.3.2. 
Consent Procedures and Documentation .....................................................................60 


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12.4. Participant and Data Confidentiality ..................................................................................61 
12.5. Future Use of Stored Specimens ........................................................................................61 
13. 
DATA HANDLING AND RECORD KEEPING ................................................................63 
13.1. Data Collection and Management Responsibilities ...........................................................63 
13.1.1. 
Investigator Responsibilities ........................................................................................63 
13.1.2. 
Study Files ...................................................................................................................63 
13.2. Study Records Retention....................................................................................................64 
13.3. Protocol Deviations ............................................................................................................64 
13.4. Publication and Data Sharing Policy .................................................................................65 
14. 
FINANCIAL DISCLOSURE AND CONFLICT OF INTEREST POLICY .......................67 
15. 
SCHEDULE OF EVENTS ...................................................................................................68 
16. 
REFERENCES .....................................................................................................................71 
16.1. Published References .........................................................................................................71 
16.2. Unpublished References ....................................................................................................73 
17. 
APPENDICES ......................................................................................................................75 
17.1. Clinical Evaluation of Liver Injury ....................................................................................75 
17.1.1. 
Introduction ..................................................................................................................75 
17.1.2. 
Procedures ....................................................................................................................75 
17.1.3. 
Case Report Form Guidelines ......................................................................................77 
17.2. Modification of Diet in Renal Disease Formula ................................................................77 
17.3. List of Prohibited Medications and Substances .................................................................78 
17.3.1. 
 
 
 
 
 
 
 
17.4. Pharmacokinetic, Biomarker, Pharmacogenomic, and Flow Cytometry/CBC 
Sampling ............................................................................................................................81 
17.5. Work Productivity and Activity Impairment Questionnaire: General Health ...................82 
18. 
REVISION HISTORY .........................................................................................................84 
18.1. Summary of Changes .........................................................................................................84 


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LIST OF TABLES 
Table 1 
Diabetic Retinopathy Severity Scale (for Individual Eyes) ...................................39 
Table 2 
Schedule of Assessments .......................................................................................68 
Table 3 
Pharmacokinetic, Biomarker, Pharmacogenomic, and Flow 
Cytometry/CBC Sampling Schedule .....................................................................81 


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CONFIDENTIAL/PROPRIETARY 
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LIST OF ABBREVIATIONS 
AE 
Adverse event 
AESI 
Adverse event of special interest 
ALP 
Alkaline phosphatase 
ALT 
Alanine aminotransferase 
AMD 
Age-related macular degeneration 
Anti-VEGF 
Anti-vascular endothelial growth factor 
ASNV 
Anterior-segment neovascularization 
AST 
Aspartate aminotransferase 
AUC 
Area under the curve 
BCVA 
Best corrected visual acuity 
b.i.d. 
Twice daily 
bpm 
Beats per minute 
BRB 
Blood-retinal barrier 
BUN 
Blood urea nitrogen 
CBC 
Complete blood count 
 
 
 
 
 
 
CFR 
Code of Federal Regulations 
ChBF 
Choroidal blood flow 
CI-DME 
Center-involved diabetic macular edema 
CK-MB 
Creatinine kinase-muscle/brain 
CLIA 
Clinical Laboratory Improvement Amendments 
Cmax 
Maximum concentration 
CMP 
Clinical monitoring plan 
CMT 
Central macular thickness 
COVID-19 
Coronavirus Disease 2019 
CRO 
Contract research organization 
CRT 
Central retinal thickness 
CSR 
Clinical study report 
CST 
Central Subfield Thickness 
 
 
DDI 
Drug-drug interaction 
DILI 
Drug-induced liver injury 
DM 
Diabetes mellitus 
DME 
Diabetic macular edema 
DNA 
Deoxyribonucleic acid 
DR 
Diabetic retinopathy 
DRSS 
Diabetic Retinopathy Severity Scale 
DRCRN 
Diabetic Retinopathy Clinical Research Network 
DSMB 
Data and Safety Monitoring Board 
ECG 
Electrocardiogram 
eCRF 
Electronic case report form 


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CONFIDENTIAL/PROPRIETARY 
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eGFR 
Estimated glomerular filtration rate 
EMA 
European Medicines Agency 
ENT 
Ear, nose, and throat 
EOS 
End-of-study 
EOT 
End-of-treatment 
 
 
ET 
Early termination 
ETDRS 
Early Treatment Diabetic Retinopathy Study 
FA 
Fluorescein angiography 
FDA 
Food and Drug Administration 
FP 
Fundus photography 
GCP 
Good Clinical Practice 
GFR 
Glomerular filtration rate 
GGT 
Gamma-glutamyl transferase 
HbA1c 
Hemoglobin A1c 
HBs 
Hepatitis B surface antigen 
HBV 
Hepatitis B virus 
HCV 
Hepatitis C virus 
HEV 
Hepatitis E virus 
HIV 
Human immunodeficiency virus 
IB 
Investigator’s Brochure 
ICF 
Informed consent form 
ICH 
International Council for Harmonisation of Technical Requirements 
for Pharmaceuticals for Human Use 
ID 
Identification 
IEC 
Independent ethics committee 
IgG 
Immunoglobulin G 
IgM 
Immunoglobulin M 
IL 
Interleukin (may be followed by an alpha-numeric designator) 
INR 
International normalized ratio 
IOP 
Intraocular pressure 
IRB 
Institutional review board 
ISF 
Investigator site file 
ITT 
Intent-to-treat 
KM 
Kaplan-Meier 
LDF 
Laser doppler flowmetry 
LKM 
Liver-kidney microsomes 
LPLV 
Last participant, last visit 
 
 
MDRD 
Modification of Diet in Renal Disease 
MedDRA 
Medical Dictionary for Regulatory Activities 
MMRM 
Mixed-effects model for repeated measures 
nAMD 
Neovascular age-related macular degeneration 
NPDR 
Nonproliferative diabetic retinopathy 
NTI 
Narrow therapeutic index 


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CONFIDENTIAL/PROPRIETARY 
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NV 
Neovascularization 
NVD 
Neovascularization of the disc 
NVE 
Neovascularization elsewhere 
OCT 
Optical coherence tomography 
OCT-A 
Optical coherence tomography angiography 
PDR 
Proliferative diabetic retinopathy 
 
 
PK 
Pharmacokinetic 
PRP 
Panretinal photocoagulation 
PT 
Prothrombin time 
PTT 
Partial thromboplastin time 
QA 
Quality assurance 
QTc 
QT interval corrected for heart rate 
QTcF 
QT interval corrected for heart rate using Fridericia’s correction 
formula 
RNA 
Ribonucleic acid 
RPE 
Retinal pigment epithelium 
RSI 
Reference Safety Information 
SAE 
Serious adverse event 
SAP 
Statistical analysis plan 
SD-OCT 
Spectral domain optical coherence tomography 
SOC 
Standard-of-care 
SUSAR 
Suspected unexpected serious adverse reaction 
TDD 
Total daily dose 
TEAE 
Treatment-emergent adverse event 
Th2 
T-helper 2 
TNF-α 
Tumor necrosis factor alpha 
UACR 
Urine albumin to creatinine ratio 
ULN 
Upper limit of normal 
US 
United States 
VF 
Visual field 
WOCBP 
Women of childbearing potential 
WPAI-GH 
Workplace Productivity and Activity Impairment General Health 


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CONFIDENTIAL/PROPRIETARY 
Page 10 of 86 
PROTOCOL APPROVAL PAGE 
 
Study Title: 
A Double-Masked, Placebo-Controlled Study to Evaluate the 
Efficacy of Oral AKST4290 in Participants with Moderately 
Severe to Severe Diabetic Retinopathy (CAPRI) 
Protocol Number: 
AKST4290-231 
Version/Date:  
2.0 (19AUG2021) 
Sponsor Name and 
Address: 
Alkahest, Inc. 
125 Shoreway Road, Suite D 
San Carlos, CA 94070 
I, the undersigned, have read and approve this protocol and agree on its content. It is confirmed 
that the information and guidance given in this protocol complies with scientific principles, the 
guidelines of Good Clinical Practice, the Declaration of Helsinki in the latest relevant version, 
and applicable legal and regulatory requirements. 
 
Approved by: 
 
  
 
 
August 19, 2021 
Sponsor Representative (print) 
 Signature  
 
Date 
 
 


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CONFIDENTIAL/PROPRIETARY 
Page 11 of 86 
STATEMENT OF COMPLIANCE 
Protocol Title: 
A Double-Masked, Placebo-Controlled Study to Evaluate the Efficacy 
of Oral AKST4290 in Participants with Moderately Severe to Severe 
Diabetic Retinopathy (CAPRI) 
Protocol Number: 
AKST4290-231 
Version/Date: 
2.0 (19AUG2021) 
By my signature, I: 
• Confirm that my staff and I have carefully read and understand this protocol or protocol 
amendment, have received the Investigator Brochure, and are thoroughly familiar with the 
appropriate use of the investigational agent described herein. 
• Agree to comply with the conduct and terms of the study specified herein and with any other 
study conduct procedures provided by the Sponsor, Alkahest, Inc., or their designee. 
• Agree to assume responsibility for the proper conduct of the study at this site, including 
complying with current relevant versions of the US Food and Drug Administration (FDA) 
regulations, European Medicines Agency (EMA), the International Council for 
Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Good 
Clinical Practice (GCP) guidelines, the Declaration of Helsinki, and all applicable rules, 
regulations, and federal, state, and local laws relating to the conduct of clinical studies and 
the protection of human research participants. 
• Agree not to implement deviations from or changes to the protocol or protocol amendments 
without agreement from the Sponsor and prior submission to and written approval (where 
required) from the Institutional Review Board (IRB) or Independent Ethics Committee (IEC), 
except when necessary to eliminate an immediate hazard to the participants, or for 
administrative aspects of the study (where permitted by all applicable regulatory 
requirements). 
• Agree to onsite monitoring of all source documents by Alkahest, Inc. or designee and to 
onsite inspection of source documents by appropriate regulatory authorities, including but not 
limited to the FDA, EMA, local governing regulatory bodies, and IRB/IEC inspectors. 
 
 
 
 
 
 
Investigator's Signature 
 
Date 
 
 
 
 
 
Print Name 
 
 
 


Protocol AKST4290-231, (Version 2.0) 
19AUG2021 
 
 
Alkahest, Inc. 
CONFIDENTIAL/PROPRIETARY 
Page 12 of 86 
PROTOCOL SUMMARY 
Title: 
A Double-Masked, Placebo-Controlled Study to Evaluate the Efficacy 
of Oral AKST4290 in Participants with Moderately Severe to Severe 
Diabetic Retinopathy (CAPRI) 
Précis:  
This study is designed to evaluate the efficacy of AKST4290 administered 
at a total daily dose (TDD) of 800 mg daily (400 mg twice daily [b.i.d.]) 
compared with placebo over a 24-week dosing period in participants with 
moderately severe nonproliferative diabetic retinopathy (NPDR) 
(Diabetic Retinopathy Severity Scale [DRSS] Level 47) to severe NPDR 
(DRSS Level 53) in one eye, and at least mild NPDR (DRSS Level 35) to 
mild proliferative diabetic retinopathy (PDR) (DRSS Level 61) in the 
other eye. Both eyes must not have center-involved diabetic macular 
edema (CI-DME) and must have good vision (defined as best corrected 
visual acuity [BCVA] of ≥ 69 letters using the Early Treatment Diabetic 
Retinopathy Study [ETDRS] method). Once enrolled, all participants will 
be evaluated monthly throughout the treatment period to assess efficacy 
and monitor overall safety, including the development of vision-
threatening complications of CI-DME, potential worsening of, or 
progression to, proliferative diabetic retinopathy (PDR), and/or anterior-
segment neovascularization (ASNV). 
Approximately 80 participants will be enrolled and allocated to 1 of 
2 treatment arms in a 2:1 randomization scheme (AKST4290:placebo). 
Participants will receive treatment for a total of 24 weeks with either 
AKST4290 800 mg daily (400 mg b.i.d.) in Arm 1 or placebo 
(matching tablets) in Arm 2.  
Objectives: 
The primary objective is to investigate the efficacy of AKST4290. 
Secondary objectives also include evaluation of efficacy as well as 
assessment of the proportion of participants who progress to CI-DME, PDR, 
and/or ASNV, and time to each of these events requiring treatment. Overall 
safety will be assessed as well as the effect of AKST4290 on diabetic kidney 
disease, and the change in Workplace Productivity and Activity Impairment 
General Health (WPAI-GH). Exploratory objectives include the assessment 
of change from Baseline in BCVA (gain or loss), macular volume, central 
macular thickness (CMT), optical coherence tomography angiography 
(OCT-A) (as available at sites), and visual field (VF) as assessed by 
perimetry/microperimetry (as available at sites). The proportion of 
participants with worsening DRSS score will also be assessed as well as 
visual acuity area under the curve (AUC). Additional exploratory objectives 
include assessment of pharmacokinetics (PK), pharmacogenomics, flow 
cytometry, complete blood count (CBC), and the presence of selected 
inflammatory biomarkers in aqueous humor samples from participants who 
elect to participate in this optional sample collection.  


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CONFIDENTIAL/PROPRIETARY 
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Endpoints: 
Primary Endpoint:  
• The proportion of participants with a ≥ 3-step improvement of 
the DRSS score from Baseline compared with Week 24. 
Secondary Endpoints:  
• The proportion of participants with a ≥ 2-step improvement of 
the DRSS score from Baseline compared with Week 24. 
• The proportion of participants progressing to the following 
vision-threatening complications that require treatment: 
CI-DME, PDR, and/or ASNV as assessed by spectral domain 
optical coherence tomography (SD-OCT), fundus photography 
(FP), and fluorescein angiography (FA), as appropriate. The 
central reading center must confirm progression to CI-DME and 
PDR before treatment is initiated; progression to ASNV, and 
subsequent treatment, does not require photo documentation. 
• Time to the following vision-threatening event(s) that require 
treatment: CI-DME, PDR, and/or ASNV. 
• Safety as assessed by incidence and intensity of adverse events 
(AEs).  
• 
Effect of AKST4290 on diabetic kidney disease as assessed by 
changes in clinical laboratory values over time (e.g., estimated 
glomerular filtration rate [eGFR], urine albumin to creatinine 
ratio [UACR]). 
• 
Change from Baseline over time in the WPAI-GH. 
Exploratory Endpoints:  
• Change from Baseline (gain or loss) over time in BCVA using 
the ETDRS method. 
• Change from Baseline over time in macular volume and CMT 
as assessed by SD-OCT. 
• Proportion of participants with a ≥ 2-step or ≥ 3-step worsening 
of DRSS score from Baseline over time. 
• BCVA, using the ETDRS method, AUC between Baseline and 
Week 24. 
• PK, pharmacogenomic, and flow cytometry/CBC evaluations of 
interest.  
• Change in area of ischemia or area of neovascularization (if 
PDR develops) from Baseline over time using OCT-A and/or 
FA (if available at the site).  
• Change from Baseline over time in VF as evaluated by 
perimetry/microperimetry (if available at the site). 
• 
Evaluation of the presence of markers of inflammation 
 
in aqueous humor in participants who elect to provide 
these samples. 


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Population: 
Approximately 80 participants are planned for enrollment to provide 
data for 69 completed participants (i.e., participants who complete the 
24-week assessments). 
Phase: 
2 
Number of Sites: 
Approximately 25 sites 
Description of Study 
Agent: 
A TDD of 800 mg of AKST4290 administered orally twice daily 
(400mg tablets b.i.d.) or matching placebo administered orally twice 
daily. 
Study Duration: 
Approximately 14 months 
Participant 
Participation: 
Approximately 32 weeks, inclusive of a 4-week Screening period, 
24-week Treatment period, and a 4-week Follow-up period. 
 
 


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SCHEMATIC OF STUDY DESIGN 
  
 


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1. 
KEY ROLES 
1.1. 
Authorized Representative (Signatory) / Responsible Party 
 
  
  
  
  
  
 
1.2. 
Study Organization 
The name and contact information of the responsible party and individuals involved with the 
study (e.g., investigator(s), Sponsor’s medical expert and study monitor, Sponsor’s 
representative(s), laboratories, steering committees, and oversight committees (including 
IRBs/IECs, as applicable) will be maintained by the Sponsor, or their designee, and provided to 
the investigator. 


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2. 
INTRODUCTION 
2.1. 
Background Information 
Diabetes mellitus (DM) is a worldwide health epidemic that is expected to increase 
exponentially. In 2018, 34.1 million adults, or 13% of all adults in the United States (US) and 
26.8% among those aged 65 years or older, had DM (CDC 2020). As of 2019, it is estimated that 
worldwide, 463 million people have DM and this number is projected to reach 578 million by 
2030, and 700 million by 2045 (IDF 2019). Despite early intervention programs and better 
methods of glycemic control, DM is one of the fastest growing health problems of the 21st 
century (IDF 2019). 
Diabetic eye disease is the most common microvascular complication of DM, and diabetic 
retinopathy (DR) is a leading cause of visual loss in working-age populations (Wang 2018). 
Among patients with DM worldwide, 35% have DR and 12% have vision-threatening diabetic 
retinopathy (DR) (IDF 2019). Hyperglycemia and resultant inflammation are considered key 
components in the pathogenesis of retinal microvascular damage (Wang 2018). The diagnosis of 
DR is made by clinical examination of the retina, which displays vascular abnormalities 
(Wang 2018). The hallmark of DR is microvascular damage to the retinal blood vessels that falls 
into 2 broad stages: the earlier stage of nonproliferative DR (NPDR) and the advanced, vision-
threatening stages in proliferative DR (PDR) (Duh 2017). In PDR, new fragile, incompetent 
vessels that are susceptible to hemorrhage grow initially from the retina and/or optic disc and 
extend beyond the internal limiting membrane. These vessels can bleed, resulting in vitreous 
hemorrhage, or they can form a fibrovascular membrane and contract, resulting in tractional 
retinal detachment. The most common cause of vision loss in DR is due to diabetic macular 
edema (DME), which can occur at any DR severity level. Diabetic macular edema is caused by 
diabetes-induced breakdown of the blood-retinal barrier (BRB) with consequent vascular leakage 
of fluid and circulating proteins into the neural retina, disrupting the macular architecture and 
function (Duh 2017).  
Without intervention, nearly half of eyes with high-risk PDR will experience profound vision 
loss from associated complications including vitreous hemorrhage or traction retinal detachment. 
Complication rates are reduced dramatically with panretinal photocoagulation (PRP) 
(DRS 1976). The Early Treatment Diabetic Retinopathy Study (ETDRS) demonstrated PRP 
reduces the risk of severe vision loss by over 90% for eyes with or approaching high risk PDR 
(ETDRS 1991a). Although remarkably effective at reducing risk of vision loss if applied in a 
timely and appropriate manner, PRP treatment destroys viable retinal tissue in the peripheral 
retina and is associated with potential adverse effects that may lead to transient or permanent loss 
of visual function, including exacerbation of existing macular edema, peripheral visual field 
defects, night vision loss, loss of contrast sensitivity, and potential complications from 
misdirected or excessive burns (Reddy 2018).   
The use of intravitreal (IVT) anti-vascular endothelial growth factor (anti-VEGF) therapy in eyes 
with PDR led to decreased risk of DR worsening (need for PRP, vitreous hemorrhage, or 
vitrectomy for complications of PDR) compared with no anti-VEGF therapy in a secondary 
outcome reported by the Diabetic Retinopathy Clinical Research Network (DRCRN) in a trial 
evaluating ranibizumab for DME (DRCRN 2010). However, some eyes still worsen despite 


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anti-VEGF therapy, and DR severity can worsen when anti-VEGF therapy is discontinued. The 
inadequate response to anti-VEGF injections may be associated with the involvement of 
molecular pathways other than VEGF during the pathogenesis of DR (Wang 2018). Studies 
investigating the underlying mechanisms of DR (e.g., inflammation) are of great importance, and 
may provide potential targets for the development of new, alternative treatments. 
Despite advances in treatment for PDR and DME, there are currently no widely used treatments 
for NPDR, leaving patients at risk for the development of DME and/or PDR. Worse baseline 
NPDR severity is strongly associated with increased risk of worsening to PDR (DRCRN 2011). 
Analysis of data from the ETDRS suggest that eyes with severe NPDR have a 52% risk of 
progressing to PDR within 1 year, and a 60% risk of worsening to PDR with high-risk 
characteristics within 5 years (DRCRN 2011). While IVT anti-VEGF therapies are Food and 
Drug Administration (FDA)-approved for severe NPDR, these treatments are not considered 
standard of care, as they are invasive, costly, and inconvenient for this stage of disease 
(AA0 2019, Solomon 2017). Treatment with PRP is performed in some select cases of severe 
NPDR; however, there is no clear treatment mandate generalizable to most eyes with severe 
NPDR that are at high risk of worsening to PDR.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


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3. 
OBJECTIVES AND PURPOSE 
3.1. 
Primary Objective 
• To investigate the efficacy of AKST4290. 
3.2. 
Secondary Objectives 
• To investigate additional measures of efficacy of AKST4290. 
• To assess the proportion of participants progressing to (or worsening of) CI-DME, PDR, 
and/or anterior-segment neovascularization (ASNV). 
• To assess the time to event of CI-DME, PDR, and/or ASNV requiring treatment. 
• To assess the overall safety of AKST4290. 
• To assess the effect of AKST4290 on diabetic kidney disease. 
• To evaluate the changes from Baseline in the Workplace Productivity and Activity 
Impairment General Health (WPAI-GH) questionnaire (Section 17.5). 
3.3. 
Exploratory Objectives 
• To assess the mean change from Baseline (gain or loss) in BCVA. 
• To assess the mean change from Baseline in macular volume and central macular thickness 
(CMT). 
• To assess the proportion of participants with worsening of Diabetic Retinopathy Severity 
Scale (DRSS) score. 
• To assess visual acuity AUC. 
• To investigate the impact of AKST4290 when administered at doses of 400 mg b.i.d. on PK, 
pharmacogenomic, and flow cytometry/complete blood count (CBC) evaluations of interest 
conducted on blood and plasma samples.  
• To evaluate changes from Baseline in optical coherence tomography angiography (OCT-A) 
(as available at sites).  
• To evaluate changes from Baseline in visual field (VF) as assessed by 
perimetry/microperimetry evaluations (as available at sites). 
• To evaluate the change from Baseline over time and the presence of inflammatory 
biomarkers including
 in 
aqueous humor collected from participants who elect to provide these samples. 


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4. 
STUDY DESIGN AND ENDPOINTS 
4.1. 
Description of the Study Design 
This is a Phase 2, double-masked, placebo-controlled multicenter study to evaluate the efficacy 
of AKST4290 administered at an 800 mg daily dose (400 mg b.i.d.) as compared with placebo 
over a 24-week dosing period in participants with moderately severe participants with 
moderately severe NPDR (DRSS Level 47) to severe NPDR (DRSS Level 53) in one eye, and at 
least mild NPDR (DRSS Level 35) to mild PDR (DRSS Level 61) in the other eye. Both eyes 
must not have CI-DME and must have good vision (defined as BCVA of ≥ 69 letters using the 
ETDRS method).    
Eligible participants will be enrolled into 1 of 2 randomized treatment arms (active and placebo) 
in a 2:1 fashion of active to placebo. Participants will receive treatment for a total of 24 weeks 
with either AKST4290 800 mg daily (400 mg b.i.d.) in Arm 1 or placebo (matching tablets) in 
Arm 2.  
Once enrolled and allocated to a randomized treatment, all participants will be evaluated monthly 
throughout the treatment period (i.e., at Visits 2, 3, 4, 5, 6, 7, and 8) to assess efficacy and 
monitor safety for the development of the vision-threatening complications of CI-DME, PDR, 
and/or ASNV. Participants who develop CI-DME (as confirmed by the central reading center), 
PDR (as confirmed by the central reading center), or ASNV (as confirmed by the investigator) 
that requires treatment will continue participation in the study. The central reading center must 
confirm progression to CI-DME or PDR before the investigator initiates treatment.  
Specific safety, tolerability, and efficacy assessments will occur at every visit as presented in the 
schedule of assessments in Section 15. At specified time points, the following assessments will 
be performed: extended ophthalmoscopy, intraocular pressure (IOP) measurement, BCVA 
testing using the ETDRS method, spectral domain optical coherence tomography (SD-OCT), slit 
lamp examination, fluorescein angiography (FA), fundus photography (FP), and gonioscopy. At 
sites with the ability to perform OCT-A and VF testing, these evaluations will be conducted. The 
WPAI-GH questionnaire will be completed throughout the treatment period. A central reading 
center will be responsible for assessing all SD-OCT, OCT-A, FP and FA images, and VF 
evaluations, to confirm study eligibility and progression to PDR and/or CI-DME and will 
provide the imaging data for inclusion in the database for the evaluation of efficacy and safety.  
Additional safety assessments will be performed at each visit and will include the incidence and 
severity of adverse events (AEs), laboratory tests, vital sign measurements, concomitant 
medication use, and any treatment for PDR, CI-DME, and/or ASNV. A 12-lead 
electrocardiogram (ECG) will be performed at selected visits as shown in the schedule of 
assessments (Section 15). Additionally, the incidence and severity of adverse events of special 
interest (AESI),
 
will be monitored. 
Blood samples for the assessment of PK, biomarkers, and pharmacogenomics will be obtained at 
various time points during the study as shown in the schedule of assessments (Section 15). 
Participation in the pharmacogenomic and aqueous humor sampling is optional and is not 


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required for participation in the study; for those participants electing to participate in either of 
these optional portions, blood samples for the assessment of pharmacogenomics and aqueous 
humor samples will be collected. 
The study will be conducted at approximately 25 sites in the US. The overall duration of the 
study, inclusive of recruitment, is approximately 14 months from study initiation (i.e., following 
consent of first participant) to study completion (i.e., last participant, last visit [LPLV]). The 
participation period for each participant is approximately 32 weeks, inclusive of a 4-week 
Screening period, 24-week Treatment period, and a 4-week Follow-up period. 
4.2. 
Study Endpoints 
4.2.1. 
Primary Endpoint 
• The proportion of participants with a ≥ 3-step improvement from Baseline on the DRSS 
score as compared with Week 24. 
4.2.2. 
Secondary Endpoints 
• The proportion of participants with a ≥ 2-step improvement from Baseline on the DRSS 
score as compared with Week 24. 
• The proportion of participants progressing to the following vision-threatening complications 
that require treatment: CI-DME, PDR, and/or ASNV as assessed by SD-OCT, FP, and FA, as 
appropriate. The central reading center must confirm progression to CI-DME and PDR 
before treatment is initiated; progression to ASNV, and subsequent treatment, does not 
require photo documentation.  
• Time to the following vision-threatening event(s) that require treatment: CI-DME, PDR, 
and/or ASNV. 
• Safety as assessed by incidence and intensity of AEs.  
• Effect of AKST4290 on diabetic kidney disease as assessed by changes in clinical laboratory 
values over time (e.g., eGFR, urine albumin to creatinine ratio [UACR]). 
• Change from Baseline over time in the WPAI-GH questionnaire (Section 17.5). 
4.2.3. 
Exploratory Endpoints 
• Change from Baseline (gain or loss) over time in BCVA using the ETDRS. 
• Change from Baseline over time in macular volume and CMT as assessed by SD-OCT. 
• Proportion of participants with a ≥ 2-step or ≥ 3-step worsening of DRSS score from 
Baseline over time. 
• BCVA, using the ETDRS, AUC between Baseline and Week 24. 


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• PK, pharmacogenomic, and flow cytometry/CBC evaluations of interest.  
• Change in area of ischemia or area of neovascularization (if PDR develops) from Baseline 
over time using OCT-A and/or FA (if available at the site).  
• Change from Baseline over time in VF as evaluated by perimetry/microperimetry (if 
available at the site). 
• Evaluation of the presence of markers of inflammation 
 in aqueous 
humor collected in a single eye in participants who elect to provide these samples. 
 


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5. 
STUDY ENROLLMENT AND WITHDRAWAL 
5.1. 
Inclusion Criteria 
In order to be eligible for inclusion, all participants must meet the following criteria: 
1. 
Age ≥ 18 years. 
2. 
Type 1 or type 2 DM. Any of the following will be considered sufficient evidence that 
diabetes is present: 
a. Current and regular use of insulin for the treatment of diabetes. 
b. Current and regular use of oral antihyperglycemic agents for the treatment of 
diabetes. 
c. Documented diabetes by ADA and/or WHO criteria. 
3. 
BCVA ETDRS visual acuity letter score ≥ 69 letters at Screening. 
4. 
Moderately severe NPDR (DRSS Level 47) to severe NPDR (DRSS Level 53) and at 
least mild NPDR (DRSS Level 35) to mild PDR (DRSS Level 61) without CI-DME in 
either eye, as determined by the investigator and as confirmed by the central reading 
center. 
5. 
Prompt PRP or anti-VEGF treatment is not required AND the investigator and potential 
participant are willing to wait for the development of high-risk characteristics (defined in 
Section 5.3) to treat PDR. 
6. 
Media clarity, pupillary dilation, and study participant cooperation sufficient to obtain 
fundus photographs, FA, and OCT images. 
7. 
The investigator and potential participant are comfortable withholding treatment for 
DME and PDR until protocol-defined treatment criteria are met (see Section 5.4). 
5.2. 
Exclusion Criteria 
An individual will not be eligible if any of the following exclusion criteria apply: 
1. 
Evidence of neovascularization (NV) (including active iris or angle NV) requiring 
treatment, per investigator discretion. Presence of NV outside of the 7-modified ETDRS 
fields on ultra-widefield imaging will not be an exclusion, provided treatment is not 
planned. Small iris tufts are NOT an exclusion. 
2. 
PRP or grid laser within 1000 microns of the foveal center. 
3. 
CI-DME on clinical examination (CI is defined as DME within 1,000 microns of the 
foveal center) and has an OCT central subfield thickness above the following gender and 
OCT machine specific thresholds:  


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a. Zeiss Cirrus: 290 µm in women and 305 µm in men. 
b. Heidelberg Spectralis: 305 µm in women and 320 µm in men.  
4. 
Prior intraocular or periocular steroid injection within 12 months prior to enrollment and 
assignment to a randomized treatment. 
5. 
Systemic anti-VEGF or pro-VEGF treatment within 4 months prior to enrollment and 
assignment to a randomized treatment. 
6. 
History of vitreoretinal surgery. 
7. 
History of major ocular surgery (including cataract extraction, scleral buckle, any 
intraocular surgery, etc.) within prior 4 months or anticipated within the next 6 months 
following randomization. 
8. 
History of DME or DR treatment with laser or intraocular injections of medication.  
a. Exception: participants with a history of treatment for DME or DR that received 
laser or intraocular injections of medication GREATER than 12 months from 
screening AND have received 4 or fewer prior injections may be enrolled up to a 
maximum of 20 participants (i.e., approximately 25% of planned sample size).  
9. 
Medical history or condition that, in the opinion of the investigator would preclude 
participation in the study, including but not limited to the following:  
a. Myocardial infarction or stroke within 12 months of Screening. 
b. Significant cardiac arrhythmia.  
c. Active bleeding disorder. 
d. Major surgery within 1 month of Screening or planned within the study period. 
e. Current, active liver disease: > 3-fold elevation of liver enzymes (alanine 
aminotransferase [ALT] and aspartate aminotransferase [AST] over upper limit of 
normal [ULN]). 
f. Uncontrolled high blood pressure (systolic blood pressure of 180 mm Hg or 
higher and/or diastolic blood pressure of 110 mm Hg or higher) despite adequate 
treatment during the 3 months prior to dosing. 
g. Positive test result for hepatitis B virus (HBV), hepatitis C virus (HCV), or human 
immunodeficiency virus (HIV) at Screening.  
h.  Unstable glycemic control. 
i. Initiation of intensive insulin treatment (a pump or multiple daily injections) 
within 4 months prior to randomization or plans to do so in the next 4 months. 


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j. Known allergy to fluorescein dye. 
10. 
 
 
  
 
 
12. 
 
13. 
 
 
14. 
Renal function as defined by eGFR < 45 mL/min/1.73 m2, using the Modification of Diet 
in Renal Disease (MDRD) study equation (see Section 17.2), at Screening.  
15. 
 
 
 
 
 
17. 
Clinically relevant abnormal laboratory value at Screening, including hematology, blood 
chemistry, or urinalysis (laboratory testing may be repeated once during the Screening 
phase). 
18. 
Significant alcohol or drug abuse within the past 2 years. 
19. 
Based on 12-lead ECG reading at Screening, participants with a risk of QT prolongation 
including: 
a. A baseline prolongation of QTc (using Fridericia’s formula: ≥ 450 ms in men and 
≥ 470 ms in women) with confirmation on a repeat ECG.  
b. A history of additional risk factors for Torsades de pointes arrhythmia (e.g., heart 
failure, hypokalemia, family history of Long QT Syndrome). 
c. The use of concomitant medications known to prolong the QT/QTc interval. 
20. 
Significant medical conditions (as determined by medical history, examination, and 
clinical investigations at Screening) that may, in the opinion of the investigator, result in 
the any of the following:  
a. Put the participant at risk because of participation in the study.  
b. Influence the results of the study.  


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c. Cause concern regarding the participant’s ability to participate in the study. 
d. Inclusion of vulnerable persons by local regulation (e.g., imprisoned or 
institutionalized).  
21. 
Malignancy for which the participant has undergone resection, radiation, or 
chemotherapy within the past 5 years (treated basal cell carcinoma or fully cured 
squamous cell carcinoma are allowed). 
22. 
Concurrent participation in another interventional clinical trial; prior clinical trial 
participants must have been off study agents for at least 30 days for small molecules, 
4 months for disease modifying therapies, and 1 year for vaccine or immunotherapy trials 
prior to Screening. 
23. 
Female participants must not be pregnant or breastfeeding. Women of childbearing 
potential (WOCBP) must have a negative pregnancy test at Screening. WOCBP must 
agree to use highly effective contraception, which includes combined (estrogen and 
progestogen containing) hormonal contraception associated with inhibition of ovulation 
(oral, intravaginal, transdermal), progestogen-only hormonal contraception associated 
with inhibition of ovulation (oral, injectable, implantable), intrauterine device, 
intrauterine hormone-releasing system, bilateral tubal occlusion, or vasectomized partner 
(Clinical Trial Facilitation Group 2014) prior to study entry. A woman is considered of 
childbearing potential following menarche and until becoming postmenopausal (no 
menses for at least 2 years without an alternative cause). Should a woman become 
pregnant or suspect she is pregnant while she or her partner is participating in the study, 
she should inform her treating physician immediately. Male participants must be willing 
to use a barrier method contraception. 
24. 
History of chronic renal failure requiring dialysis or kidney transplant. 
5.3. 
Initiation of Treatment for Proliferative Diabetic Retinopathy  
Treatment for PDR must not be given until one of the following criteria has been met:  
1. The eye has PDR with high-risk characteristics, defined as: 
a. Neovascularization of the disc (NVD) greater than Standard photograph 10A (1/4 
to 1/3 disc area), or 
b. Any NVD with pre-retinal or vitreous hemorrhage, or 
c. Neovascularization elsewhere (NVE) greater than 1/2 disc area with pre-retinal or 
vitreous hemorrhage. 
2. The eye has vitreous hemorrhage requiring treatment that is presumed to be from PDR 
(either NV identified on FA or unable to assess NV due to the density of the hemorrhage, 
but there is no other attributable cause).  


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3. NV of the iris (at least 2 cumulative clock hours), definitive NV of the angle, or 
neovascular glaucoma development on clinical exam (photographic documentation not 
required) 
4. The central reading center has confirmed NV is present within the 7-modified fields and 
approval from Sponsor medical monitor has been received to initiate treatment prior to 
high-risk characteristics being present. 
Note: Treatment for NVE outside of the 7-modified fields without the presence of pre-retinal or 
vitreous hemorrhage is discouraged. 
5.4. 
Initiation of Treatment for Center-involved Diabetic Macular Edema  
Treatment for CI-DME must not be given until all the following criteria have been met: 
1. At least a 10% increase in OCT central subfield thickness from baseline as confirmed by 
the central reading center. 
2. Confirmed visual acuity loss presumed to be from DME, which is defined as either  
a. at least a 10-letter loss from baseline at a single visit, OR 
b. 5- to 9-letter losses at 2 consecutive visits that are at least 21 days apart. 
5.5. 
Strategies for Recruitment and Retention 
The Sponsor does not anticipate any specific challenges in meeting recruitment goals of 
enrolling and retaining a total of approximately 80 participants in this study. Participants will be 
recruited continuously until the planned sample size is achieved. Participants who withdraw or 
are withdrawn during Screening, as well as participants who discontinue, may be replaced (see 
Section 5.6.2).  
The anticipated length of participation in the study of approximately 32 weeks is not expected to 
be challenging to participants. Financial support for meals and miscellaneous expenses will be 
available during the study, as appropriate and based on local regulations and guidelines. Use of 
visit transport services may also be incorporated into the trial to support the participant in 
maintaining study visit compliance. A description of the study will be included in local clinical 
trial databases, as required. 
5.6. 
Participant Withdrawal  
5.6.1. 
Reasons for Withdrawal 
A participant may be withdrawn from study treatment for the following medical or 
administrative reasons: 
• Occurrence of an AE that represents an unacceptable risk to the participant and when 
continued participation in the investigational study is not warranted, in the judgment of the 


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investigator, Sponsor, or medical monitor. The investigator must follow the participant until 
the AE resolves or is stable unless the participant is lost to follow up. 
○ Discontinuation of the investigational product for liver enzyme abnormalities (confirmed 
upon repeat testing) is required if:  
• ALT or AST ≥ 8× ULN;  
• ALT or AST ≥ 5× ULN for more than 2 weeks;  
• ALT or AST ≥ 3× ULN and (total bilirubin > 2× ULN or international normalized 
ratio (INR) > 1.5);  
• ALT or AST ≥ 3× ULN with new symptoms of fatigue, nausea, vomiting, right upper 
quadrant pain or tenderness, dark urine, or new clinical signs of fever, rash, jaundice, 
eosinophilia (> 5%), or encephalopathy. 
• Treatment with a prohibited concomitant medication other than the use of appropriate 
medications for the treatment of AEs under direction of the investigator. 
• Participant noncompliance, defined as refusal or inability to adhere to the trial schedule or 
procedures. 
• At the request of the participant (e.g., participant withdraws consent), investigator, Sponsor, 
or regulatory authority. 
• Pregnancy. 
5.6.2. 
Handling of Participant Withdrawals 
Participants will be encouraged to complete the study and all assessments. Participants may 
voluntarily withdraw at any time, and the investigator may discontinue individual participants 
from the study at any time.  
Approximately 80 participants are planned for enrollment to provide data for 69 completed 
participants (i.e., participants who complete the 24-week assessments). Participants who 
withdraw or are withdrawn may be replaced; enrollment will continue to ensure that data from 
69 completed participants are available. Participants who withdraw or are withdrawn due to AEs 
or adverse reactions based on study procedures will not be replaced.  
Participants who have received at least 1 tablet of study drug but are withdrawn or withdraw 
from the study will be encouraged to complete the end-of-treatment (EOT) procedures. The 
primary reason for study discontinuation will be documented on the electronic case report form 
(eCRF). 


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5.7. 
Premature Termination or Suspension of Study 
The Sponsor reserves the right to terminate the study at any time. Should this be necessary, the 
Sponsor and/or their representatives will arrange discontinuation procedures and notify the 
appropriate regulatory authority(ies), IRBs, and IECs. In terminating the study, the Sponsor and 
the investigator will continue to protect the participant’s privacy and identity as required by 
relevant statues and regulations. 
Alkahest, Inc. has the right to terminate a study site from participating in the study at any time. 
Reasons for study or site termination may include, but are not limited to: 
• Immediate risk to participant safety. 
• Unsatisfactory participant enrollment. 
• Unacceptable protocol deviations/violations as assessed by the medical monitor. 
• Inaccurate or incomplete data entry and recording/fabricated data. 
• Investigational site non-compliance with ICH GCP. 
• Unacceptable emergent safety profile. 


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6. 
STUDY AGENTS 
6.1. 
Study Agent and Control Description 
6.1.1. 
Acquisition 
The study agent (AKST4290) and placebo will be manufactured, labeled, packaged, and 
distributed by Alkahest, Inc.  
6.1.2. 
Formulation, Appearance, Packaging, and Labeling 
AKST4290 is a film-coated pink, oblong tablet manufactured by Alkahest, Inc., with a unit 
strength of 400 mg and is packaged in “foil-foil” blister packets. Each packet will include 
14 tablets. The study agent (AKST4290) and matching placebo will be delivered to the site and 
labeled for investigational use only according to the relevant regulatory requirements for clinical 
studies.  
AKST4290 shows acceptable aqueous solubility and a low intrinsic permeability. Formulation 
development focused on protection from water due to the high hygroscopicity and sensitivity 
toward hydrolytic cleavage. 
6.1.3. 
Product Storage and Stability 
The study agent and matching placebo will be kept in its original packaging in a secure limited 
access storage area at 15° C to 30° C. A temperature log must be maintained to make certain the 
study agent is stored at the correct temperature. If the storage conditions are found to be outside 
the specified range, the site must immediately notify the sponsor or designee. 
6.1.4. 
Dosing and Administration 
Study drug will be self-administered orally b.i.d., approximately 12 hours apart. AKST4290 will 
be administered as a TDD of 800 mg (400 mg b.i.d.). Matching placebo will be self-administered 
orally b.i.d. following the same dosing instructions as AKST4290.  
Participants will receive training on study drug administration prior to initial study drug 
administration at Visit 2. Study drug will be self-administered in the clinic under the supervision 
of study personnel during every in-clinic visit of the Treatment Period (Visits 2-8) after any 
pre-dose assessments (including PK sample collection), and then self-administered at home 
between study visits.  
When study drug is dispensed, participants will receive a total of 5 packets, which represents a 
5-week supply (4 weeks of treatment plus an additional week). Study drug accountability will be 
assessed by packet. 
6.2. 
Study Agent Accountability 
The investigator and/or pharmacist will receive AKST4290 and placebo delivered by the 
Sponsor when the following requirements are fulfilled: 


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• Approval of the study protocol and informed consent by the IRB or IEC. 
• Availability of a signed and dated clinical trial contract between the Sponsor and the 
investigational site. 
• Approval/notification of the appropriate regulatory authority. 
• Availability of the curriculum vitae of the principal investigator. 
• Availability of a signed and dated clinical trial protocol or immediately imminent signing of 
the clinical trial protocol. 
The investigator and/or pharmacist must maintain records of the delivery of the AKST4290 and 
placebo to the trial site, the inventory at the site, the use by each participant, and the return to the 
Sponsor or alternative disposition of unused AKST4290 and/or placebo.  
These records will include dates, quantities, batch/serial numbers, expiry (‘use by’) dates, and 
the unique code numbers assigned to AKST4290, placebo, and study participants. The 
investigator/pharmacist will maintain records that document adequately that the participants were 
provided the doses specified by the protocol and reconcile all AKST4290 and placebo received 
from the Sponsor. At the time of final AKST4290 and placebo reconciliation, the 
investigator/pharmacist must verify that all unused or partially used portion of AKST4290 and/or 
placebo have been returned by the clinical trial participants and that no remaining AKST4290 
and/or placebo are retained by the investigator. 
Accountability records must be maintained and readily available for monitoring and auditing 
purposes by representatives of Alkahest, Inc., or their designee and are open to inspection by 
regulatory authorities at any time. The accounts of any AKST4290 and/or placebo accidentally 
wasted or intentionally disposed of must be maintained.  
The disposal of used, partially used, or wasted AKST4290 and/or placebo must be performed in 
accordance with the institution’s drug disposal policy or return. At study initiation, the clinical 
study monitor will evaluate the site’s standard operating procedure for study drug 
disposal/destruction to ensure it complies with study requirements. At the end of the study, 
following final AKST4290 and placebo reconciliation by the monitor, the study site will be 
instructed by the sponsor to return or destroy all unused AKST4290 and placebo. A copy of the 
institution’s drug disposal policy should be maintained or referenced in the investigator site file 
(ISF), if applicable. 


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7. 
STUDY PROCEDURES AND SCHEDULE 
7.1. 
Study Procedures and Evaluations 
7.1.1. 
Study Specific Procedures 
Before any study-related procedures are performed, which includes medication washouts and 
restrictions, all participants must sign an informed consent that is consistent with ICH-GCP 
guidelines. For those participants electing to participate in the optional pharmacogenomics 
and/or optional aqueous humor portions of the study, separate informed consents must be 
obtained for deoxyribonucleic acid (DNA) banking and aqueous humor collection. 
A central reading center will be responsible for assessing all SD-OCT, OCT-A, FP, VF, and FA 
images to confirm study eligibility and progression to PDR and/or CI-DME and will provide the 
imaging data for inclusion in the database for the evaluation of efficacy and safety. 
7.1.1.1. 
Screening Procedures 
During Screening, the following will be performed: 
• All ophthalmological evaluations: 
• 
BCVA, as assessed by ETDRS (see Section 7.1.1.3.2 for a description of the 
procedures). 
• 
OCT (SD-OCT and/or OCT-A [if available at the site]) (see Section 7.1.1.3.3 for a 
description of the procedures). 
• 
Extended ophthalmoscopy (see Section 7.1.1.3.4 for a description of the 
procedures).   
• 
Slit lamp examination (see Section 7.1.1.3.4 for a description of the procedures). 
• 
IOP (see Section 7.1.1.3.4 for a description of the procedures). 
• 
Gonioscopy (see Section 7.1.1.3.4 for a description of the procedures). 
• 
FP evaluation and FA (see Section 7.1.1.3.5 for a description of the procedures). 
• Medical history (see Section 7.1.1.1.1 for a description of the procedures). 
• Demographics (see Section 7.1.1.1.2 for a description of the procedures). 
• Review of medications (see Section 7.1.1.2.2 for a description of the procedures). 
• Vital signs (see Section 7.1.1.2.3 for a description of the procedures). 
• 12-lead ECG (see Section 7.1.1.2.4 for a description of the procedures). 


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• Physical examination (full) (see Section 7.1.1.2.5 for a description of the procedures). 
• Blood and urine sample collection for laboratory evaluations, including pregnancy testing in 
WOCBP (see Section 7.1.1.2.6 for a description of the procedures). 
Detailed descriptions of each of these procedures are provided in the sections immediately 
following. The Schedule of Events is presented in Section 15. 
7.1.1.1.1. 
Medical History 
The investigator or designee will obtain a detailed medical history by interviewing the 
participant during Screening. The medical history should focus on recent history, with an 
emphasis on the history of DR and any associated ocular procedures and/or medications. 
Additionally, the medical history should include: 
• Current/past illnesses and conditions. 
• Current symptoms of any active medical condition. 
• Surgeries and procedures. 
• Allergies. 
• Social history (e.g., smoking, alcohol, illegal substances). 
7.1.1.1.2. 
Demographics 
Demographic information such as the participant’s age, ethnicity, and race will be collected by 
interview with the participant at Screening. 
7.1.1.2. 
Procedures to Assess Safety 
Participants enrolled in the study will be monitored closely to assess safety and tolerability of the 
AKST4290 and placebo. Study-specific procedures that will be used for this purpose are 
summarized below. Information regarding the timing and frequency of these procedures is 
provided in the Schedule of Events (Section 15).  
• Review of AEs (see Section 7.1.1.2.1 for a description of the procedures). 
• Review of medications (see Section 7.1.1.2.2 for a description of the procedures). 
• Vital signs (see Section 7.1.1.2.3 for a description of the procedures). 
• 12-lead ECG (see Section 7.1.1.2.4 for a description of the procedures). 
• Physical examination (targeted) (see Section 7.1.1.2.5 for a description of the procedures). 


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• Blood and urine sample collection for laboratory evaluations, including pregnancy testing in 
WOCBP (see Section 7.1.1.2.6 for a description of the procedures). 
• All ophthalmological evaluations: 
• 
BCVA, as assessed by ETDRS (see Section 7.1.1.3.2 for a description of the 
procedure). 
• 
OCT (SD-OCT and/or OCT-A [if available at the site]) (see Section 7.1.1.3.3 for a 
description of the procedures). 
• 
Extended ophthalmoscopy (see Section 7.1.1.3.4 for a description of the 
procedure).   
• 
Slit-lamp examination (see Section 7.1.1.3.4 for a description of the procedure). 
• 
IOP (see Section 7.1.1.3.4 for a description of the procedure). 
• 
Gonioscopy (see Section 7.1.1.3.4 for a description of the procedure). 
• 
FP and FA (see Section 7.1.1.3.5 for a description of the procedures). 
• 
VF measured by perimetry/microperimetry (if available at the site (see Section 
7.1.1.3.6 for a description of the procedures). 
7.1.1.2.1. 
Review of Adverse Events 
Adverse events will be reviewed, documented, and reported as required at each visit, beginning 
at Screening. For definitions, guidance, and additional information regarding AEs, refer to 
Section 8.  
7.1.1.2.2. 
Review of Medications 
At Screening, the investigator or designee should obtain a complete list of the participant’s 
current medications, including over-the-counter drugs, herbal supplements and/or vitamins, as 
well as those taken by the participant in the past 3 months. Assessment of eligibility should 
include a review of permitted and prohibited medications. Throughout the study, any additions, 
discontinuations, or dosage changes in medication will be recorded. Additionally, any treatments 
or therapies administered for the treatment of PDR and/or CI-DME will be recorded.  
7.1.1.2.3. 
Vital Signs 
Vital sign measurements will include seated systolic and diastolic blood pressure (mm Hg), heart 
rate (beats per minute [bpm]), respiration rate (breaths per minute), and body temperature. Vital 
signs will be measured after the participant has been seated for 5 minutes. 


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7.1.1.2.4. 
12-lead Electrocardiogram 
Twelve-lead ECGs (I, II, III, aVR, aVL, aVF, V1 - V6) will be recorded using a computerized 
electrocardiograph. A 12-lead ECG will be performed after the participant has rested quietly for 
at least 5 minutes in a supine position. In some cases, it may be appropriate to repeat abnormal 
ECGs to rule out technical factors contributing to ECG artifacts or abnormality. It is important 
that leads are placed in the same positions each time for consistency. The final interpretation of 
the ECGs will be recorded on the appropriate eCRF. The interpretation of the ECGs will be 
recorded as normal, abnormal but not clinically significant, or abnormal and clinically 
significant. Corrected QTc will be calculated using Fridericia’s correction formula (QTcF). 
7.1.1.2.5. 
Physical Examination 
At Screening, a full physical examination will be performed to assess the following organ 
systems: skin, ENT (ears, nose, and throat), head, eyes, lungs/chest, heart, abdomen, 
musculoskeletal, extremities, and lymphatic systems. Height and weight will be measured. 
During the study period, a targeted physical examination, including auscultation of the heart and 
measurement of weight as well as review of any previous abnormalities identified during the full 
physical examination. 
7.1.1.2.6. 
Blood and Urine Collection for Laboratory Evaluations 
Blood and urine samples will be collected according to the Schedule of Events (Section 15). 
Laboratory tests will include hematology, chemistry, serology, coagulation, and qualitative 
urinalysis, and pregnancy testing in WOCBP.  
• Hematology: hemoglobin, hematocrit, red blood cell count, white blood cell count with 
differential 
 and platelets. 
• Chemistry: HbA1c, glucose, sodium, potassium, calcium, inorganic phosphate, chloride, 
bicarbonate, magnesium, creatinine, AST, ALT, alkaline phosphatase (ALP), lactate 
dehydrogenase, direct and indirect bilirubin, blood urea nitrogen (BUN), total protein, 
albumin, and eGFR. 
• Serology: HBV, HCV, and HIV. 
• Coagulation: partial thromboplastin time (PTT), and prothrombin time (PT). 
• Urinalysis: pH, glucose, erythrocytes, leukocytes, protein, nitrites, and UACR. 
• Pregnancy: pregnancy testing will be performed at the site in either urine or serum; a positive 
test result must be confirmed by a serum pregnancy test performed by the central laboratory. 
Additional laboratory parameters may be reported as detailed in the laboratory manual. 
Glomerular filtration rate (GFR) will be estimated by the MDRD Formula utilizing serum 
creatinine (see Section 17.2).  


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All safety laboratory measurements will be performed by a Clinical Laboratory Improvement 
Amendments (CLIA)-certified laboratory. Investigators will receive guidance and instructions on 
laboratory sampling and processing through a separate laboratory manual provided by the central 
laboratory. 
The investigator is responsible for reviewing and documenting all laboratory results and 
determining if out-of-range laboratory values are clinically significant. All clinically significant 
values will be recorded as AEs in the eCRF and followed until resolution. Once resolved, the 
appropriate eCRF page(s) will be updated.  
Samples may be used for re-testing, further evaluation of an AE and/or assessment, and 
follow-up of other exploratory endpoints. Samples that remain after study testing is complete 
will be stored in the event additional testing (e.g., further evaluation of an AE or assessment of 
effect) is required. Samples will be stored in a deidentified coded form. Participants can opt out 
of storage of samples for future analysis. 
7.1.1.3. 
Procedures to Assess Efficacy 
7.1.1.3.1. 
Diabetic Retinopathy Severity Scale 
Progression of DR can be measured in discrete steps as described by the DRSS (ETDRS 1991b, 
Staurenghi 2018). This scale is well established for objective quantification of retinopathy 
severity and a validated method for quantification of DR change. When the scale is used for 
assessing change in overall retinopathy severity, classifying patients by retinopathy level in each 
eye (rather than by the worse eye, or by the right or left eye alone) retains prognostic information 
that would otherwise be lost (ETDRS 1991b).  
The DRSS divides DR into 13 levels ranging from the absence of retinopathy to severe 
retinopathy (see Table 1). The DRSS can be used to describe overall DR severity as well as the 
change in severity over time (ETDRS 1991b). Further, DRSS scores are associated with the risk 
for the development of PDR (ETDRS 1991b, Staurenghi 2018). Findings from FP and FA, as 
provided by the central reading center, will be used to determine the DRSS score for each 
participant. 


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Table 1 
Diabetic Retinopathy Severity Scale (for Individual Eyes) 
Level 
Severity 
Definition 
10 
DR absent 
Microaneurysms and other characteristics absent 
20 
Microaneurysms only 
Microaneurysms definite; other characteristics absent 
35 
Mild NPDR 
One or more of the following: 
• 
Venous loops ≥ D/1 
• 
SE, IRMA, or VB = Q 
• 
Retinal hemorrhages present 
• 
HE ≥ D/1 
• 
SE ≥ D/1 
43 
Moderate NPDR 
H/Ma = 4-5 – S/1 or IRMA = D/1-3 (not both) 
47 
Moderately severe NPDR 
Both L43 characteristics and/or 1 (only) of the following: 
• 
IRMA = D4-5 
• 
H/Ma = S/2-3 
• 
VB = D1 
53 
Severe NPDR 
One or more of the following: 
• 
≥ 2 of the 3 L47 characteristics 
• 
H/Ma ≥ S/4-5 
• 
IRMA ≥ M/1 
• 
VB ≥ D/2-3 
61 
Mild PDR 
FPD or FPE present with NVD and NVE absent; or NVE = D 
65 
Moderate PDR 
Either of the following: 
• 
NVE ≥ M/1 or NVD = D and VH or PRH = A or Q 
• 
VH or PRH = D and NVE < M/1 and NVD absent 
71 
High-risk PDR 
Any of the following: 
• 
VH or PRH ≥ M/1 
• 
NVE ≥ M/1 and VH or PRH ≥ D/1 
• 
NVD = 2 and VH or PRH ≥ D/1 
• 
NVD ≥ M 
75 
High-risk PDR 
NVD ≥ M and VH or PRH ≥ D/1 
81 
Advanced PDR: fundus partially 
obscured, center of macula 
attached 
NVD = cannot grade, or NVD < D and NVE = cannot grade 
in ≥ 1 field and absent in all others; and retinal detachment at 
center of macula < D 
85 
Advanced PDR: posterior fundus 
obscured, or center of macula 
detached 
VH = VS in fields 1 and 2; or retinal detachment at center of 
macula = D 
90 
Cannot grade, even sufficiently for 
level 81 or 85 
 
Abbreviations: A = absent; D = definitely present; DR = diabetic retinopathy; DRSS = Diabetic Retinopathy 
Severity Scale; FPD = fibrous proliferations disc; FPE = fibrous proliferations elsewhere; HE = hard exudates; 
H/Ma = hemorrhages/microaneurysms; IRMA = intraretinal microvascular abnormalities; M = moderate; NPDR = 
nonproliferative diabetic retinopathy; NVD = neovascularization of the disc (within one disc diameter of disc 
margin); NVE = neovascularization elsewhere (>1 disc diameter from disc); PDR = proliferative diabetic 
retinopathy; PRH = preretinal hemorrhage; Q = questionable; S = severe; SE = soft exudates; VB = venous beading; 
VH = vitreous hemorrhage; VS = very severe. 
Severity categories for characteristics graded in multiple fields are of the form ‘maximum severity/extent’, where 
maximum severity can be (A), (Q), (D), (M), (S), or (VS), and the extent is the number of fields at that severity 
level. For example, M/2–3 means that there are 2 or 3 fields from fields 3 to 7 with moderate severity, and none with 
higher severity. 
Source: ETDRS 1991b, Staurenghi 2018 


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7.1.1.3.2. 
Best-Corrected Visual Acuity using the Early Treatment Diabetic 
Retinopathy Study Method 
Best-corrected visual acuity will be assessed using ETDRS charts at 4 meters initial testing 
distance and assessed in both eyes. The trained technician measuring the BCVA using ETDRS 
should be the same throughout the study period. A detailed manual for performing refractions 
and measuring BCVA using the ETDRS testing method will be provided to investigators. 
7.1.1.3.3. 
Optical Coherence Tomography 
The retinal layers of both eyes will be visualized, and thickness measured by SD-OCT and, if 
available at the site, additional scans using OCT-A will be obtained. For sites with the capability 
to perform OCT-A, these assessments should be performed at Visit 2 (Baseline) and Visit 8 
(EOT/end of study [EOS]). Both eyes will be investigated by a trained technician using only 
specified SD-OCT equipment. A detailed manual for SD-OCT and OCT-A image acquisition 
and data transmission will be provided in the ISF. The reported central subfield thickness (CST) 
will be exclusive of the sub-RPE fluid. 
7.1.1.3.4. 
Slit Lamp Examination, Extended Ophthalmoscopy, Intraocular 
Pressure Measurement, and Gonioscopy 
The slit lamp examination, IOP measurement, gonioscopy, and extended ophthalmoscopy are to 
be performed in both eyes. The anterior and posterior segments of the eye should be assessed. 
Extended ophthalmoscopy is an assessment of the peripheral retina, usually performed with a 
20 diopter lens and an indirect ophthalmoscope, to examine for retinal abnormalities such as 
retinal tears, detachment, hemorrhage, retinal artery perfusion, etc. Intraocular pressure will be 
measured using applanation Goldmann tonometry in both eyes during each visit. A gonioscope, 
together with a slit lamp or operating microscope, will be used to view the iridocorneal angle. 
Extended ophthalmoscopy is an assessment of the peripheral retina after pupillary dilation, 
usually performed with a 20 diopter lens and an indirect ophthalmoscope, to examine for retinal 
abnormalities such as neovascularization, retinal tears, detachment, retinal hemorrhage, etc. 
7.1.1.3.5. 
Fundus Photography and Fluorescein Angiography 
After pupillary dilation, the retina of both eyes will be imaged by FP and FA. Both eyes will be 
investigated by a trained technician and evaluated by the investigator. A detailed manual for FP 
and FA will be provided in the ISF. 
7.1.1.3.6. 
Visual Field Testing 
Evaluation of VF will be conducted using perimetry and/or microperimetry, per site availability. 
Evaluations of VF take approximately 10-20 minutes and are useful for assessment of some or 
all of the following (depending on the equipment used): peripheral vision, retinal sensitivities at 
specific retinal locations, and/or structural/functional analysis of the central retina.  


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7.1.1.3.7. 
Workplace Productivity and Activity Impairment Questionnaire 
The WPAI-GH V2.0 is a 6-question survey used to assess the effects of a participant’s health 
problems (i.e., physical or emotional problems or symptoms) on their ability to work and 
perform regular activities during the past 7 days (Section 17.5). In clinical trials, the WPAI-GH 
has been used to compare work impairments between treatment groups in participants with 
varying levels of disease severity (Zhang 2010).  
7.1.1.3.8. 
Aqueous Humor Testing 
In consenting participants, aqueous humor samples will be obtained as indicated in the Schedule 
of Events (Section 15) to evaluate potential biomarkers of inflammation, pathogenesis, and 
disease progression. Participation in aqueous humor sampling is optional. 
Details of aqueous humor collection, sample processing and handling, and shipment instructions 
will be provided in the laboratory manual. 
7.2. 
Laboratory Procedures and Evaluations 
7.2.1. 
Clinical Laboratory Evaluations 
Biological samples (e.g., whole blood, serum, urine) will be collected for laboratory evaluations, 
including pregnancy testing in WOCBP, in accordance with the Schedule of Events (Section 15). 
Refer to the study’s laboratory manual for complete information regarding all laboratory 
evaluations to be performed, sample collection procedures, and related requirements. 
The investigator is responsible for determining and documenting whether out-of-range laboratory 
values are clinically significant. All clinically significant values will be recorded as AEs in the 
eCRF and followed until determined to be stable or resolved unless the participant is lost to 
follow-up. Once resolved, the appropriate eCRF page(s) will be updated. 
7.2.2. 
Other Tests or Procedures 
7.2.2.1. 
Study Agent Concentration and Pharmacokinetics 
Plasma concentration measurements of AKST4290 and its major metabolite will be collected to 
assess systemic exposure. For sampling time points and further details, please refer to 
Section 17.4.  
For quantification of plasma concentrations of AKST4290 and its major metabolite, and for 
biomarker investigations (see Section 7.2.2.2), one blood sample of approximately 6 mL per 
sampling time point (see Section 17.4) will be taken from an antecubital or forearm vein into a 
potassium EDTA-anticoagulant blood drawing tube. 
Details of plasma collection, sample processing and handling, and shipment instructions will be 
provided in the laboratory manual. 


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7.2.2.2. 
Plasma Biomarkers 
Measurement of biomarkers is exploratory. Investigations might include mechanism related 
markers 
 that could 
identify subsets of participants who may benefit most from the treatment with AKST4290.
 
 
Biomarkers will be measured in plasma samples to investigate any change in response to 
treatment. After completion of the study, any remaining samples may be used for further 
methodological and/or other, non-genetic biomarker investigations either by the sponsor, or 
designee. The study samples will be discarded after completion of the additional investigations, 
but not later than 3 years after the final study report has been archived. The exploratory 
biomarker measurements will be conducted either at the sponsor’s laboratories or at external 
contract research organizations (CROs) using appropriate methodology (e.g., immunoassays, 
multiplex technology).  
Details of plasma collection, sample processing and handling, and shipment instructions will be 
provided in the laboratory manual. 
7.2.2.3. 
Blood Biomarkers by Flow Cytometry 
Characterization of immune cells using flow cytometry/CBC is exploratory. For the 
investigations, one blood sample of approximately 6 mL per sampling time point will be 
collected. Specimens must be transported for testing within a specified time period. The 
exploratory biomarker measurements using flow cytometry/CBC will be conducted either at the 
sponsor’s laboratories or at external CRO’s laboratory using appropriate methodology (e.g., 
immunoassays, multiplex technology). A Laboratory Manual/ISF will describe the handling of 
the samples. 
7.2.2.4. 
Pharmacogenomic Evaluation 
Pharmacogenetic analysis of prespecified genes is mandatory and a prerequisite for participation 
in this study. Furthermore, samples for DNA banking will be collected if participants signed a 
separate informed consent, but is not required for study participation.  
• Prespecified genes: DNA will be extracted from 1 blood sample and genotyped for common 
genetic variants of the following genes: 
 
 
 
 
 
 
 
 
• 
Prespecified analyses will be performed at the end of the trial and the data will be 
part of the report. All remaining samples will be destroyed after the end of the trial. 


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• DNA banking: One blood sample will be collected for retrospective, exploratory genotyping 
(e.g., to analyze disease or treatment-related gene variants). For information regarding future 
use of stored samples, see Section 12.5. 
One 3-mL blood sample for prespecified pharmacogenomic testing will be obtained at Visit 2 in 
a potassium EDTA-anticoagulant blood drawing tube. For participants who agreed to DNA 
banking, one 8.5-mL blood sample will be taken at Visit 2 in a PAXgene Blood DNA sampling 
tube (see Section 17.4). The sample will be taken from an antecubital or forearm vein into a 
potassium EDTA-anticoagulant blood drawing tube.  
Details of plasma collection, sample processing and handling, and shipment instructions will be 
provided in the laboratory manual. 
7.3. 
Study Schedule 
7.3.1. 
Screening 
The Screening visit will occur between 2 to 28 days (Days -28 to -2) before the Baseline visit on 
Day 1. The assessments to be performed at Screening are detailed in the Schedule of Events in 
Section 15. 
7.3.2. 
Treatment 
The 24-week Treatment Period comprises Visit 2 (Baseline/Day 1) through Visit 8 
(EOT/ET/Day 168). The assessments to be performed at each visit during the Treatment Period 
are detailed in the Schedule of Events in Section 15. 
7.3.3. 
Early Termination or Withdrawal 
In cases of early termination (ET) or withdrawal, if a participant has received at least 1 dose of 
AKST4290 or placebo, the site should try to perform all assessments scheduled for Visit 8 
(EOT/Day 168) and for the subsequent Follow-up Visit (Visit 9 [EOS]) unless the participant has 
withdrawn consent (see Section 5.5). 
7.3.4. 
Study Completion and End of Study 
Study completion or EOS is defined as the end of participation for each enrolled participant. This 
will occur at Visit 9 unless a participant withdraws or is withdrawn (see Section 5.5 and 
Section 7.3.3, respectively). If a participant has withdrawn consent, study completion will be at 
the time of consent withdrawal and no further procedures will be performed. The EOS will occur 
following the last participant’s last visit.  
7.3.5. 
Schedule of Events Table 
The Schedule of Events is presented in Section 15. 


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7.4. 
Concomitant Medications 
All prescription, over-the-counter, and non-prescription medications (including herbal therapies 
and supplements) must be documented in the source documents and eCRFs. All participants 
should be maintained on the same medications at the same dosage and administration throughout 
the entire study period, as medically feasible, with no introduction of new chronic therapies. Any 
changes in medications (additions, deletions, dosage changes) should be documented in the 
eCRF with reason for change (e.g., AEs). 
7.5. 
Prohibited Medications, Treatments, and Procedures 
Treatment with anti-VEGF and intraocular or periocular steroid injection is prohibited before the 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
  


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8. 
ASSESSMENT OF SAFETY 
Assessment of safety will be conducted by masked study personnel except in extraordinary 
circumstances where knowledge of whether AKST4290 or placebo was received by a participant 
is essential. Any instances of unmasking will be managed as indicated in Section 10.6.3. 
8.1. 
Specification of Safety Parameters 
8.1.1. 
Definition of Adverse Events 
Per 21 Code of Federal Regulations (CFR) 312.32(a) an AE is any untoward (unfavorable, 
harmful, or pathologic) medical occurrence in a participant administered a pharmaceutical 
(investigational) product even if the event does not necessarily have a causal relationship with 
this treatment.  
An AE can, therefore, be any unfavorable and unintended sign (including an abnormal laboratory 
finding that is deemed clinically significant), symptom, or disease temporally associated with the 
use of a medicinal (investigational) product whether or not related to the medicinal 
(investigational) product. 
An AE does include any: 
• Exacerbation of a pre-existing illness. 
• Subjective or objective symptoms spontaneously offered by the participant and/or observed 
by the investigator or study staff. 
• Increase in frequency or intensity of a pre-existing episodic event or condition. 
• Condition detected or diagnosed after study drug administration even though it may have 
been present prior to the start of the study (unless it can be demonstrated by medical record 
review that the onset of the event preceded the date/time of informed consent). 
• Continuous persistent disease or symptoms present at baseline that worsen following the start 
of the study. 
• Symptoms associated with disease not previously reported by the participant. 
• Untoward medical occurrences considered by the investigator to be related to study-
mandated procedures. 
• Abnormal assessments (e.g., change on physical examination, ECG findings), if they 
represent a clinically significant finding, that were not present at baseline or worsened during 
the course of the study. 
• Laboratory test abnormalities, if they represent a clinically significant finding, symptomatic 
or not, which were not present at baseline or worsened during the course of the study. 


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An AE DOES NOT include a/an: 
• Elective medical or surgical procedure (e.g., surgery, endoscopy, tooth extraction, 
transfusion).  
• Pre-existing diseases or conditions present or detected at the start of the study that do not 
worsen. 
• Situations where an untoward medical occurrence has not occurred (e.g., hospitalization for 
cosmetic elective surgery, social and/or convenience admissions). 
• Overdose of either study drug or concurrent medication without any signs or symptoms. 
• Pregnancy. 
8.1.2. 
Definition of Serious Adverse Events 
Note: if either the investigator or the Sponsor believes that the event is serious, the event must be 
considered serious and evaluated for expedited reporting.  
Note: the terms “severe” and “serious” are not synonymous. Severity (or intensity) refers to the 
grade of an AE. “Serious” is a regulatory definition.  
A SAE (experience) or reaction is an untoward medical occurrence that, at any dose, fulfills one 
or more of the following criteria: 
a. Results in death (i.e., the AE actually causes or leads to death). 
b. Is life-threatening. 
• An AE is considered “life-threatening” if, in the view of either the investigator or 
Sponsor, its occurrence places the patient or participant at immediate risk of death; it 
does not include AEs which, had it occurred in a more severe form, might have caused 
death. 
c. Results in inpatient hospitalization or prolongation of existing hospitalization. 
• Hospitalization for elective treatment of a pre-existing condition that did not worsen 
during the study is not considered an AE; hospitalization for participating in this study 
is not considered an AE. 
• Complications that occur during hospitalization are AEs; if a complication prolongs 
hospitalization, the event is an SAE. 
• “Inpatient” hospitalization means the participant has been formally admitted to a 
hospital for medical reasons that may or may not be overnight; it does not include 
presentation at a casualty or emergency room unless the event meets the definition of 
an Important Medical Event (in the opinion of the Investigator or Sponsor). 


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d. Results in persistent or significant incapacity or substantial disruption of the ability to 
conduct normal life functions. 
• The term ‘disability’ means a substantial disruption of a person’s ability to conduct 
normal life functions; this definition is not intended to include experiences of relatively 
minor medical significance such as uncomplicated headache, nausea, vomiting, 
diarrhea, influenza, accidental trauma (i.e., sprained ankle) that may interfere or 
prevent everyday life functions but do not constitute a substantial disruption. 
e. Results in a congenital anomaly in the offspring of a participant who received drug. 
f. Results in an Important Medical Event. Important Medical Events are events that may not 
result in death, be life-threatening, or require hospitalization but may be considered an 
SAE when, based upon appropriate medical judgment, they may jeopardize the 
participant and may require medical or surgical intervention to prevent one of the 
outcomes listed in this definition; examples of such medical events include allergic 
bronchospasm requiring intensive treatment in an emergency room or at home, blood 
dyscrasias or convulsions that do not result in inpatient hospitalization, or the 
development of drug dependency or drug abuse. 
• Medical and scientific judgment should be used in deciding whether prompt reporting 
is appropriate in this situation. 
8.2. 
Classification of An Adverse Event 
8.2.1. 
Severity of Event 
Each AE or suspected adverse reaction must be assessed for its seriousness and severity. Severity 
will be assessed by the investigator or designee using the following definitions: 
 
SEVERITY 
DEFINITION 
MILD 
Aware of sign or symptom, but easily tolerated 
MODERATE 
Discomfort enough to cause interference with usual activity 
SEVERE 
Incapacitating with inability to work or do usual activity 
Outcome will be assessed using the following categories: recovered/resolved, not recovered/ not 
resolved, recovered/resolved with sequelae, fatal, or unknown. 
The following guidelines are to be applied to facilitate classification of the severity of AEs 
related to liver enzyme abnormalities (with or without bilirubin elevations): 
• Elevations in ALT and/or AST ≥ 3× ULN but < 5× ULN confirmed on repeat testing are 
considered mild in severity and should be recorded separately on the AE log. 


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• Elevations in ALT and/or AST ≥ 5× ULN confirmed on repeat testing are considered at least 
moderate in severity and should be recorded separately on the AE log. 
• Elevations in ALT and/or AST ≥ 3× ULN and a total bilirubin elevation > 2× ULN meet the 
protocol definition for an AESI (Section 8.4.3) of DILI, are considered severe, and meet the 
criteria for classification as an SAE per protocol definitions.   
NOTE: Any of these cases can be classified as an SAE if any of the criteria defining an SAE 
apply. 
8.2.2. 
Relationship to Study Agent 
Investigators are required to assess the causal relationship (i.e., whether there is reasonable 
possibility that the study drug caused the event) using the following definitions: 
• Unrelated: another cause of the AE is more plausible; a temporal sequence cannot be 
established with the onset of the AE and administration of the study agent; or a causal 
relationship is considered biologically implausible. 
• Possibly Related: There is a clinically plausible time sequence between onset of the AE and 
administration of the study agent, but the AE could also be attributed to concurrent or 
underlying disease, or the use of other drugs or procedures. Possibly related should be used 
when the study agent is one or several biologically plausible AE causes. 
• Definitely Related: The AE is clearly related to use of the study agent. 
If either the investigator or the Sponsor considers the event related, then the event will be 
considered related for reporting purposes. 
8.2.3. 
Expectedness 
The Sponsor or designee will be responsible for determining whether an AE is expected or 
unexpected. An AE will be considered unexpected if the nature, severity, or frequency of the 
event is not consistent with the Reference Safety Information (RSI) described in the 
Investigator’s Brochure (IB). 
For example, under this definition, hepatic necrosis would be unexpected (by virtue of greater 
severity) if the IB referred only to elevated hepatic enzymes or hepatitis. Similarly, cerebral 
thromboembolism and cerebral vasculitis would be unexpected (by virtue of greater specificity) 
if the IB listed only cerebral vascular accidents. "Unexpected" as used in this definition, also 
refers to AEs or suspected adverse reactions that are mentioned in the IB as occurring with a 
class of drugs or as anticipated from the pharmacological properties of the drug but are not 
specifically mentioned as occurring with the particular drug under investigation. For example, 
although angioedema is anticipated to occur in some patients exposed to drugs in the 
angiotensin-converting enzyme inhibitor class and angioedema would be described in the IB as a 
class effect, the first case of angioedema observed with the drug under investigation should be 
considered unexpected for reporting purposes (FDA 2012). 


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This definition of “unexpected” relies entirely on the RSI in the IB as the basis for determining if 
newly acquired information generated from clinical trials or reported from other sources is 
unexpected. The suspected adverse reactions listed in the IB (i.e., “expected”) are those observed 
with the investigational drug and for which a causal relationship between the event and the drug 
is suspected or confirmed. 
Sponsor assessment of expectedness and relationship to study drug/causality will determine the 
need for expedited reporting of AEs. 
8.3. 
Time Period/Frequency for Event Assessment/Follow-up 
At every clinic visit, participants who have given informed consent will be assessed for AEs and 
SAEs. After the participant has had an opportunity to spontaneously mention any problems, the 
investigator should inquire about AEs by asking a non-leading question such as the following: 
1. “How are you feeling?” 
2. “Have you had any changes since your last assessment/visit?” 
3. “Have you taken any new medicines since your last assessment/visit?” 
8.3.1. 
Post-Study Adverse Event and Serious Adverse Event 
The investigator is not obligated to actively seek SAE information in former study participants, 
but the investigator is encouraged to notify Alkahest, Inc. or their designee of any AE or SAE 
occurring within 30 days after a participant completes the study (or has their last visit) that the 
investigator judges may be reasonably related to study treatment or study participation. 
8.4. 
Reporting Procedures 
8.4.1. 
Adverse Event Reporting 
All participants who have given informed consent will be evaluated for AEs. All AEs that occur 
after the time of treatment with the study drug will be considered treatment-emergent AEs 
(TEAEs). Participants with TEAEs must be followed until the AE is resolved or is stable, unless 
the participant is lost to follow up. 
Each AE or suspected adverse reaction must be described as follows: the date of onset, date of 
resolution, severity (mild, moderate, severe), frequency of the event (single episode, intermittent, 
continuous), action taken with study treatment (no action taken, treatment held, treatment 
discontinued), outcome, causality* (unrelated, possibly related, definitely related), and 
seriousness criteria. Each AE or suspected adverse reaction must be recorded separately. 
*Note: Causality assessment will be made only when the AE occurs after the participant has 
initiated at least 1 dose of the study agent. An AE occurring before the participant’s exposure to 
study agent will always be labeled as “unrelated”. 


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Any AE occurring during the study must be documented in the participant’s medical records and 
as an AE in the eCRF. Any SAE occurring during the study must be documented in the 
participant’s medical records and as an SAE in the eCRF. 
A separate set of SAE pages should be used for each SAE. However, if at the time of initial 
reporting, multiple SAEs are present that are temporally and/or clinically related, they may be 
reported on the same SAE page. 
The investigator should attempt to establish a diagnosis of the event (that meets the definition of 
an AE or SAE) based on signs, symptoms, and/or other clinical information. In such cases, the 
diagnosis should be documented as the AE and/or SAE and not the individual signs or 
symptoms. The diagnosis will become the basis for the verbatim term as reported by the 
investigator. If no diagnosis is known and clinical signs and symptoms are not present, the 
abnormal finding should be recorded. 
In addition to the investigator’s own description of the AE, each AE will be encoded according 
to the Medical Dictionary for Regulatory Activities (MedDRA). 
The investigator will take all appropriate and necessary therapeutic measures required for 
resolution of the AE. Any medication necessary for the treatment of an AE must be recorded on 
the concomitant medication eCRF. 
The SAE pages of the CRF should be completed as thoroughly as possible and signed by the 
investigator or his/her designee before transmittal to the study CRO. It is very important that the 
investigator provide his/her assessment of causality to study drug as well as an applicable 
diagnosis at the time of the initial SAE report. 
8.4.2. 
Serious Adverse Event Reporting 
8.4.2.1. 
Timeframes for Reporting Serious Adverse Events 
Under 21 CFR 312.32(c), the Sponsor is required to notify FDA, European Medicines Agency 
(EMA), and all participating investigators in a safety report of potentially serious risks from 
clinical trials (i.e., Suspected Unexpected Serious Adverse Reactions [SUSARS]), as soon as 
possible after the Sponsor receives the safety information and determines that the information 
qualifies for reporting: 
• No later than 7 calendar days for events that are life threatening (in the opinion of the 
investigator or the Sponsor) or that involve death as an outcome. 
• No later than 15 calendar days for all other SUSARS. 
As such, prompt notification of the Sponsor, and/or the Sponsor’s representatives, and promptly 
providing requested follow up information regarding SAEs is essential so that ethical and 
regulatory responsibilities and legal obligations can be satisfied. Investigators are responsible for 
reporting SAEs according to the following timeframes: 
• All SAEs occurring during the study should be reported immediately. 


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• The SAE Report Form and relevant source documents, if applicable, must be completed and 
emailed to the drug safety representative within 24 hours of observation or learning of the 
event.  
NOTE: Contact information for the drug safety representative will be provided on the SAE 
forms and in the ISF. 
• Follow up information must be sent to the CRO within 24 hours of receipt of information by 
the investigational site. 
Serious adverse events will be followed until resolution, the condition stabilizes, the event is 
otherwise explained or is judged by the investigator to be no longer clinically significant, or until 
the participant is lost to follow up. 
8.4.2.2. 
Serious Adverse Event Information to Report 
All information available regarding an SAE must be submitted in the timeframes indicated. At a 
minimum, SAE reports must contain the participant identification (ID), the SAE verbatim term, 
onset date, relationship to study drug/causality, and a brief narrative of the event. Please note that 
relationship to study drug/causality as well as the reported verbatim term are very important and 
should be included in the initial report as it may impact expedited regulatory reporting 
requirements for the event. The date of SAE discovery by the site staff should be documented in 
the source documents. 
The investigator must record all relevant information regarding an AE/SAE in the applicable 
sections of the eCRF. It is not acceptable for the investigator to send photocopies of the 
participant’s medical records in lieu of completion of the appropriate AE/SAE pages. However, 
there may be instances when copies of medical records for certain cases are requested by the 
CRO and/or the Sponsor. If medical records are submitted to the CRO then all participant 
personal identifiers must be completely and thoroughly redacted prior to submission. 
A blank SAE Report Form and instructions for SAE reporting will be provided to the site and 
will be maintained in the investigator’s study file. The SAE Report Form must be completed and 
emailed to the drug safety representative according to the timeframes specified in 
Section 8.4.2.1. The SAE Report Form should include copies of relevant source documents, if 
applicable. Reconciliation of any discrepancy noted during monitoring and amending the eCRF 
is required. 
If new information about an SAE is received or corrections to data are needed, the investigator 
should complete a new SAE Report Form and check the “follow-up” box on the form. This 
follow-up SAE Report Form should be submitted within 24 hours of learning of the information, 
especially if the new information concerns seriousness, relatedness, or the event term of an AE. 
Sites acting under their local IRB/IEC should submit all applicable events, unanticipated 
problems, and safety reports to the site’s local IRB/IEC, if applicable. All safety reporting 
deviations should also be submitted to their local IRB/IEC, if applicable. 


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8.4.3. 
Adverse Events of Special Interest 
 
 
 
 
 
 
 
 
 
AESIs occurring during the study should be reported within 48 hours of observation or learning 
of the event, unless the event is serious, in which case the event must be reported according to 
the timeframes specified in Section 8.4.2.1. 
8.4.4. 
Reporting of Pregnancy 
While pregnancy itself is not considered an AE, pregnancy occurring in a clinical study must be 
followed to collect information regarding the experiences of gestation and pregnancy with study 
agent exposure. The investigator must report any pregnancy that occurs in a female study 
participant or female partner of a male participant subsequent to first exposure to the study agent 
until the EOT visit, or 3 months following a participant’s last dose in the event of early 
withdrawal. All pregnancies will be reported to the IRB/IEC, Sponsor, and CRO. In the event of 
a pregnancy, treatment will be discontinued, and the participant will undergo continued safety 
follow up through pregnancy outcome. The study blind can be broken for safety reasons if the 
information is required for the management of pregnancy. Any noted intentional or unintentional 
breaking of the blind should be reported to the Sponsor’s study team lead and quality group 
(see Section 10.6.3). 
Any pregnancy must be followed by the investigator until delivery or to the end of pregnancy. 
Any anomalies, complications, abnormal outcomes, or birth defect(s) observed in the child must 
be reported as an SAE within 24 hours of the investigator or study personnel’s first knowledge. 
8.5. 
Study Halting Rules 
The Data Safety Monitoring Board (DSMB) will make recommendations concerning the 
continuation, modification, or termination of the study.  
8.6. 
Safety Oversight 
Safety oversight will be provided by the Sponsor’s program physician or his or her designee and 
the CRO’s medical monitor(s) in concert with the site investigators. Additionally, a DSMB will 
be established. Members of the DSMB will be independent from the study conduct and free of 
actual or perceived conflict of interest. 


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The DSMB will meet at least quarterly (or more frequently as needed) to assess safety data. The 
DSMB will operate under the rules of an approved charter that will be written and reviewed at 
the organizational meeting of the DSMB. At this time, each data element that the DSMB needs 
to assess will be clearly defined. The DSMB will provide its input to Alkahest, Inc. 
In addition, the Sponsor will perform ongoing monitoring of cumulative safety data in a 
systematic manner to ensure that any safety signals that may impact the overall benefit/risk ratio 
in this specific population will be detected, assessed, and any necessary action taken. Blinded 
cumulative safety data (e.g., AE listings, vital sign plots, safety laboratory values, ECGs, 
physical examination results) will be reviewed by the CRO’s Medical Monitor(s) and/or by the 
Sponsor’s Program Physician throughout the study. If either physician detects any safety trends 
of concern, an ad-hoc meeting of the DSMB may be triggered. 


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9. 
CLINICAL MONITORING 
Clinical site monitoring is conducted to ensure that the rights and wellbeing of human research 
participants are protected, that the reported study data are accurate, complete, and verifiable, and 
that the conduct of the study is in compliance with the currently approved 
protocol/amendment(s), with GCP, and with applicable regulatory requirement(s). 
• Monitoring for this study will be performed by the study CRO in accordance with the 
Clinical Monitoring Plan (CMP). 
• A mix of onsite and centralized risk-based monitoring will be performed to ensure the safety 
of clinical research participants and the accuracy and completeness of study data. 
• The Sponsor will be provided with copies of monitoring reports per the timelines specified 
within the CMP. 
• Details of clinical site monitoring tasks and scope are documented in the study’s CMP. The 
CMP describes in detail who will conduct monitoring, at what frequency monitoring will be 
done, at what level of detail monitoring will be performed, and the distribution of monitoring 
reports. 
• Independent audits may be conducted by the Sponsor’s Quality Assurance (QA) function or 
Sponsor contracted QA consultants in accordance with a study specific QA plan to ensure 
monitoring practices are performed consistently across all participating sites, that monitors 
are following the CMP and sites conduct the study according to the protocol, GCP, and 
applicable regulatory requirements. 


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10. 
STATISTICAL CONSIDERATIONS 
10.1. Statistical Design Model and Analytical Plans 
A Statistical Analysis Plan (SAP) with analytical details and assumptions will be developed and 
finalized before database lock and unmasking of the study data. 
10.2. Statistical Hypotheses 
The primary efficacy endpoint is the proportion of participants with a ≥ 3-step improvement in 
the DRSS score from baseline  at Week 24. The null hypothesis to be tested is that there is no 
difference between AKST4290 (A) and placebo (P) in the proportion of participants with a 
≥ 3-step improvement at Week 24: 
H0: pA = pP 
The alternate hypothesis is that there is a difference in the treatment group proportions: 
H1: pA ≠ pP. 
10.3. Analysis Datasets 
The Intent-to-Treat (ITT) Population will include all participants allocated to a randomized 
treatment.  
The Safety Population will include all participants who receive at least 1 dose of the study drug.  
10.4. Description of Statistical Methods 
10.4.1. 
General Approach 
The ITT Population will be the primary population used for efficacy analyses. For the purposes 
of the efficacy analysis, the treatment assignment will be according to the randomization 
schedule. 
The Safety Population will be the primary population used for the safety analyses. For the 
purposes of the safety analysis, the treatment assignment will be according to the treatment the 
participant actually received. 
10.4.2. 
Analysis of the Primary Endpoint 
The primary estimand is the difference between treatment groups in the proportion of 
participants with a ≥ 3-step improvement from Baseline on the DRSS score at Week 24, among 
participants in the ITT Population. Participants who have missing data at the Week 24 time point 
will be considered non-responders. The proportion of participants with improvement at Week 24 
will be compared among treatment groups using a Cochran-Mantel-Haenszel chi-square test, 
stratified by the DRSS category at Baseline (moderately severe or severe). 


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10.4.3. 
Analysis of the Secondary Endpoints 
Analysis of the secondary endpoints will be based on the ITT Population. 
The proportion of participants with a ≥ 2-step improvement from Baseline on the DRSS score at 
Week 24, as well as the proportion of participants progressing to CI-DME, PDR, and/or 
requiring ASNV requiring treatment, will be analyzed using a similar method as described for 
the primary endpoint. 
Time to the event of CI-DME, PDR, and/or ASNV requiring treatment will be summarized using 
Kaplan-Meier (KM) methodology. Participants who do not experience the event will be censored 
at the time of their last non-missing evaluation. AKST4290 will be compared to placebo using 
the stratified log-rank test, stratified by the DRSS category at Baseline (moderately severe or 
severe). Kaplan-Meier estimates of the survival distribution function over time will be plotted by 
treatment group. 
Clinical changes in diabetic kidney disease related laboratory values (e.g., eGFR and UACR) 
will be analyzed by a mixed-effects model for repeated measures (MMRM). The model will 
include fixed effects for treatment group, categorical visit, treatment group by visit interaction, 
the DRSS category at Baseline (moderately severe or severe), and the relevant Baseline value as 
a covariate. An appropriate covariance structure will be selected prior to database lock and the 
Kenward-Roger approximation will be used to calculate the denominator degrees of freedom for 
the test of fixed effects. 
Safety will be assessed through summaries of AEs, changes in laboratory test results, and 
changes in vital sign measurements. In addition, all SAEs, including deaths, will be listed and 
summarized separately. 
10.4.4. 
Analysis of the Exploratory Endpoints 
Changes in BCVA (gain or loss) using the ETDRS, macular volume, and CMT as assessed by 
SD-OCT, WPAI-GH questionnaire, and OCT-A over time will be analyzed using an MMRM 
model similar the one described above.  
The proportion of participants with a ≥ 2-step or ≥ 3-step worsening of the DRSS score from 
Baseline will be analyzed using a similar method as described for the primary endpoint. 
The AUC between Baseline and Week 24 in BCVA using the ETDRS will be analyzed by an 
analysis of covariance model with a main effect for treatment group, a classification factor for 
the DRSS category at Baseline (moderately severe or severe), and the Baseline BCVA value as a 
covariate. 
Other exploratory endpoints will be summarized with descriptive statistics and/or counts and 
percentages of participants in each category of interest. 
10.4.5. 
Planned Interim Analyses 
No interim analysis is planned. 


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10.4.6. 
Multiple Comparison/Multiplicity 
The analysis of the single primary endpoint to compare AKST4290 with placebo will be 
evaluated at the 2-sided 5% level of significance. Analysis of secondary endpoints will be 
adjusted for multiple endpoint or treatment group comparisons. Analysis of any exploratory 
endpoints will be exploratory in nature and not based on any formal hypothesis testing. Details of 
all analyses will be provided in the SAP. 
10.5. Sample Size 
Due to a dearth of studies with a 3-step improvement, as well as potential variabilities between 
each eye, the sample size is powered on the primary hypothesis comparing the difference 
between treatment arms (AKST4290 and placebo) in the proportion of participants with a ≥ 2-
step improvement of DR severity level on DRSS score in a single eye from Baseline as 
compared with Week 24. All calculations were based on the following fixed assumptions: 
• Target 80% power. 
• 2-sided alpha = 0.046. 
○ It should be noted that to account for DSMB interim data reviews, the alpha spending 
approach has been adopted using an alpha reduction of 0.001 for each review (assuming a 
total of 4 reviews). The required sample size does not change if only three DSMB 
meetings are necessary.  
• Test of 2 independent proportions based on the normal approximation. 
• Based calculation on PANORAMA (NCT02718326, EYLEA Full Prescribing Information), 
RISE/RIDE (Nguyen 2012, Wykoff 2018), and VIVID/VISTA (Korobelnik 2014, Brown 
2015) study data. 
The total sample size using the assumptions stipulated is approximately 80 enrolled participants 
to allow for a total of 69 completed participants. The randomization schema is 2:1 
(AKST4290:placebo). Group sample sizes of 46 in the AKST4290 group and 23 in the placebo 
group will achieve approximately 80% power to detect a difference in group proportions of 24%. 
The proportion in the AKST4290 group is assumed to be 6% under the null hypothesis and 
30% under the alternate hypothesis. The proportion in the placebo group is assumed to be 6%. 
10.6. Measures to Minimize Bias 
10.6.1. 
Enrollment/Randomization/Masking Procedures 
To minimize the potential bias at the time of randomization, the study will be double-masked and 
randomized in a 2:1 ratio (active 400 mg b.i.d: placebo b.i.d.) based on a block randomization 
schema. The randomization will be stratified by DRSS category at Baseline (moderately severe 
to severe NPDR). The randomization codes will be generated by a statistician who is not 
involved in the study other than generation and maintenance of the randomization codes. 


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10.6.2. 
Evaluation of the Success of Masking 
The success of masking will be assessed based on all occurrences (intentional or unintentional) 
of unmasking of masked study participants or study personnel (e.g., investigators, medical 
providers, assessors, the Sponsor, or their representatives). All intentional and unintentional 
unmasking will be documented and reported. 
10.6.3. 
Breaking the Study Mask and/or Participant Code 
The study mask for either AKST4290 versus placebo can be broken for safety reasons if the 
information is required for the management of SAEs, severe AEs, or pregnancies. Before 
breaking the mask, every attempt should be made to discuss the need with the Sponsor program 
physician, or designee. When some degree of unmasking must occur, this should be limited to 
the fewest number of people on a need-to-know basis. 
The investigator can obtain the AKST4290 or placebo treatment allocation for their participant 
through the web-based randomization system. In the rare event the web-based system is 
unavailable, 
 is available 24 hours/day, 7 days/week at: 
Email:  
  
Toll-free: 
 
Any noted intentional or unintentional breaking of the mask should be reported to the Sponsor’s 
study team lead and quality group. If unintentional unblinding occurs during the study, root 
cause analysis will be evaluated, and corrective actions implemented. 


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11. 
SOURCE DOCUMENTS AND ACCESS TO SOURCE DATA/DOCUMENTS 
Each participating site will maintain appropriate medical and research records for this study, in 
compliance with ICH E6 R2 and regulatory and institutional requirements for the protection of 
confidentiality of participants. Each site will permit authorized representatives of regulatory 
agencies, the IRB/IEC, the Sponsor, or the Sponsor’s representatives to examine (and when 
permitted by applicable law, to copy) clinical records for the purposes of QA reviews, audits, and 
evaluation of the study safety, progress, and data validity. 
Source data are all information, original records of clinical findings, observations, or other 
activities in a clinical study necessary for the reconstruction and evaluation of the study. 
Examples of these original documents and data records include, but are not limited to, hospital 
records, clinical and office charts, laboratory notes, memoranda, participant’s memory aids or 
evaluation checklists, pharmacy dispensing records, recorded audio tapes of counseling sessions, 
recorded data from automated instruments, copies or transcriptions certified after verification as 
being attributable, legible, accurate and complete, microfiches, photographic negatives, 
microfilm or magnetic media, x-rays, and participant files and records kept at the pharmacy, at 
the laboratories, and medico-technical departments involved in the clinical trial. 
It is not acceptable for the eCRF to be the only record of a participant’s participation in the 
study. This is to ensure that anyone who would access the participant’s medical record has 
adequate knowledge that the participant is participating in a clinical trial. Source document 
templates will be developed for this study. 


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12. 
ETHICS/PROTECTION OF HUMAN SUBJECTS 
12.1. Ethical Standard 
The investigator will ensure that this study is conducted in full conformity with Regulations for 
the Protection of Human Subjects of Research codified in 45 CFR Part 46, 21 CFR Part 50, 
21 CFR Part 56, ICH E6 R2, 21 CFR Part 320, Retention of Bioavailability and Bioequivalence 
Testing Samples (1993), and the Declaration of Helsinki. 
12.2. Institutional Review Board 
This protocol and any accompanying material to be provided to the participant (such as 
advertisements, participant information sheets, or descriptions of the study used to obtain 
informed consent) will be submitted by the investigator to an IRB or IEC. Approval from the 
IRB/IEC must be obtained before starting the study and should be documented in a letter to the 
investigator specifying the protocol number, protocol version, documents reviewed, and date on 
which the committee met and granted the approval. 
All changes to the consent form will be IRB/IEC approved; a determination will be made 
regarding whether previously consented participants need to be re-consented. 
Any modifications or amendments to the protocol must also be submitted to the IRB/IEC for 
approval prior to implementation. 
12.3. Informed Consent Process 
12.3.1. 
Consent Forms 
Consent forms describing in detail the study agent, study procedures, and risks are given to the 
participant or healthcare power of attorney or equivalent legal representative, and written 
documentation of informed consent is required prior to any study-related procedures. 
12.3.2. 
Consent Procedures and Documentation 
It is the responsibility of the investigator or designee to obtain written informed consent form(s) 
(ICF) each participant participating in this study after adequate explanation of the aims, methods, 
objectives, and potential hazards of the study and prior to undertaking any study-related 
procedures. 
Participants should have the opportunity to discuss the study with their family members or other 
advisors and the time to consider participation in the study carefully. The participants may 
withdraw consent at any time throughout the course of the study. The rights and welfare of the 
participants will be protected by emphasizing to them that the quality of their medical care will 
not be adversely affected if they decline to participate in this study. 
The investigator or designee must utilize an IRB/IEC approved consent form that contains the 
elements required by ICH GCP and applicable regulatory requirements for documenting written 
informed consent. Each ICF will be appropriately signed and dated by the participant and the 


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person obtaining consent. A copy of the signed ICF will be provided to the participant. By 
signing the ICF, all parties agree they will complete the evaluations required by the study, unless 
they withdraw voluntarily or are terminated from the study for any reason. 
Investigators will be expected to maintain a screening log of all potential study candidates that 
includes limited information about the potential candidate (e.g., date of screening). 
All participants who provide consent will be assigned a unique study number. This number will 
be used to identify the participant throughout the clinical study and must be used on all study 
documentation related to the study participant. Once a number is assigned to a participant, that 
number will remain with that study participant and will not be reused. 
If an individual’s medical chart or results of diagnostic tests performed as part of an individual’s 
regular medical care are going to be used for Screening, written informed consent must be 
obtained prior to review of that information in accordance with Health Insurance Portability and 
Accountability Act. 
12.4. Participant and Data Confidentiality 
Participant confidentiality is held in strict trust by the participating investigators, their staff, the 
Sponsor, and their agents. This confidentiality is extended to cover testing of biological samples 
and genetic tests in addition to the clinical information relating to participants. Therefore, the 
study protocol, documentation, data, and all other information generated will be held in strict 
confidence. No information concerning the study or data will be released to any unauthorized 
third party without prior written approval of the Sponsor. 
The study monitor, other authorized representatives of the Sponsor, representatives of the 
IRB/IEC, or government regulatory agencies may inspect documents and records required to be 
maintained by the investigator, including but not limited to, medical records (office, clinic, or 
hospital) and pharmacy records for the participants in this study. The clinical study site will 
permit access to such records. 
The investigator must assure that participants’ anonymity will be strictly maintained and that 
their identities are protected from unauthorized parties. An identification code (i.e., not names) 
should be recorded on non-local laboratory samples, requisitions, and any documents submitted 
to the CRO, Sponsor, and/or IRB/IEC. The investigator must keep a participant log showing 
codes, names, and addresses for all participants screened and for all participants enrolled in the 
study. The study participant’s contact information will be securely stored at each clinical site for 
internal use during the study. At the end of the study, all records will continue to be kept in a 
secure location for as long a period as dictated by local IRB/IEC and institutional regulations. 
12.5. Future Use of Stored Specimens 
With the participant’s approval and as approved by local IRB/IECs, de-identified biological 
samples may be stored at Alkahest, or designee, for future use. These samples could be used for 
research and to improve treatment. Alkahest will also be provided with a code-link that will 
allow linking the biological specimens with the specific data from each participant, maintaining 


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the masking of the identity of the study participant. Participants may choose whether the Sponsor 
can store and use samples for further research. 
During the conduct of the study, an individual participant can choose to withdraw consent to 
have biological specimens stored for future research.  
When the study is completed, access to study data and/or samples will be managed by Alkahest. 
In the event Alkahest transfers ownership to another commercial Sponsor, ownership of the 
samples may be transferred as well. 


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13. 
DATA HANDLING AND RECORD KEEPING 
13.1. Data Collection and Management Responsibilities 
Data collection is the responsibility of the clinical trial staff at the site under the supervision of 
the site investigator. The investigator is responsible for ensuring the accuracy, completeness, and 
timeliness of the data reported. 
Source documents provide evidence for the existence of the participant and substantiate the 
integrity of the data collected. Source documents are filed at the investigator’s site. Data entered 
in the eCRFs that are transcribed from source documents must be consistent with the source 
documents or the discrepancies must be explained. All source documents should be completed in 
a neat, legible manner to ensure accurate interpretation of data. Black or blue ink is required to 
ensure clarity of reproduced copies. When making changes or corrections, cross out the original 
entry with a single line, and initial and date the change. DO NOT ERASE, OVERWRITE, OR 
USE CORRECTION FLUID OR TAPE ON THE ORIGINAL. The investigator may need to 
request previous medical records or transfer records, depending on the trial; also, current medical 
records must be available. 
For each participant who receives the study agent or placebo, the eCRF must be completed in a 
timely manner. The investigator will review and approve the eCRF for each study participant 
after all data have been entered, the eCRFs have been source document verified, and all queries 
have been resolved. This also applies to records for those participant who fail to complete the 
study. If a participant withdraws from the study, the reason must be noted on the eCRF. If a 
participant is withdrawn from the study because of an AE, thorough efforts should be made to 
clearly document the outcome. 
All data collection and recordkeeping procedures must be compliant with applicable ICH GCP. 
13.1.1. 
Investigator Responsibilities 
The investigator will comply with the protocol (which has been approved/given favorable 
opinion by an IRB/IEC), ICH GCP, and applicable regulatory requirements. The investigator is 
ultimately responsible for the conduct of all aspects of the study at the study site and verifies by 
signature the integrity of all data transmitted to the Sponsor. The term “investigator” as used in 
this protocol as well as in other study documents, refers to the investigator or authorized study 
personnel that the investigator has designated to perform certain duties. Sub-investigators as 
listed on Form FDA 1572 or other authorized study personnel are eligible to sign for the 
investigator, except where the investigator’s signature is specifically required. 
13.1.2. 
Study Files 
The investigator must maintain adequate and accurate records to enable the conduct of the study 
to be fully documented and the study data to be subsequently verified. These documents should 
be classified into 2 separate categories (although not limited to) the following: (1) investigator’s 
study file, and (2) participant clinical source documents. 


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The investigator’s study file will contain the clinical study protocol/amendments, IB, eCRF, 
IRB/IEC approval with correspondence, ICFs, drug records, staff curriculum vitae and 
authorization forms, and other appropriate documents and study specific manuals 
(e.g., Laboratory Manual). 
Participant clinical source documents would include (although are not limited to) the following: 
participant hospital/clinic records, physician’s and nurse’s notes, appointment book, original 
laboratory reports, ECG, radiologic imaging, X-ray, pathology and special assessment reports, 
consultant letters, screening, and enrollment log, etc. 
13.2. Study Records Retention 
All clinical study documents must be retained by the investigator until 2 years after the study is 
discontinued and regulatory authorities have been notified. Before the investigator destroys any 
material related to the clinical study, he/she must obtain approval in writing from the Sponsor. 
The investigator should keep a file where the full name and address of the participant and all 
signed informed consents are included for at least 15 years after completion of the study. Any 
original study-related information that permits verification of inclusion and exclusion criteria, 
including clinical history, a copy of all data collection logs, and documents on the use of the 
study agent, must be stored for as long a time period as permitted by the center. 
Should the investigator wish to move study records to another location, arrangements must be 
made to store these in sealed containers so that they can be returned sealed to the investigator in 
case of a regulatory audit. Where source documents are required for the continued care of the 
participant, appropriate copies should be made for storage outside of the site. 
13.3. Protocol Deviations 
A protocol deviation is any noncompliance with the clinical trial protocol or with GCP. The 
noncompliance may be either on the part of the participant, the investigator, or the study site 
staff. When deviations occur, corrective actions are to be developed by the site and implemented 
promptly. 
These practices are consistent with ICH E6: 
• 4.5 Compliance with Protocol, sections 4.5.1, 4.5.2, and 4.5.3. 
• 5.1 Quality Assurance and Quality Control, section 5.1.1. 
• 5.20 Noncompliance, sections 5.20.1, and 5.20.2. 
Protocol deviations will be categorized as either Major or Minor and will be defined in the study 
specific Protocol Deviation Plan. 
Major protocol deviations are departures from the approved protocol relating to the conduct of 
the study that may affect the rights, safety, and/or well-being of study participants or the study 
outcomes or data quality. Major protocol deviations may result in data that are not deemed 


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evaluable for the per-protocol analysis and/or may require that participants are discontinued from 
the study. Major protocol deviations are Significant Clinical Issues. Note: observations 
categorized as Major may include those situations where there is a pattern of deviation, 
numerous Minor observations, or other significant deviation. 
Minor protocol deviations are departures from the approved protocol relating to the conduct of a 
study that does not affect the rights, safety, and/or well-being of study participants or the study 
outcomes or data quality. Minor protocol deviations would not generally preclude participant 
data from the per-protocol analysis population. 
Note: persistently missed or incomplete study procedures and/or study evaluations will be 
considered Major protocol deviations. 
Coronavirus Disease 2019 (COVID-19) protocol deviations are departures from the approved 
protocol related to the COVID-19 pandemic. Window extensions and missed protocol 
assessments may be permitted to reduce the risk of COVID-19 exposure. Any deviation to the 
protocol to reduce the risk of COVID-19 will be captured as a “Protocol Deviation related to 
COVID-19” to categorize the anticipated increase in protocol deviations due to the pandemic. In 
addition, protocol deviations that have been prospectively identified and that can be implemented 
to reduce the risk of exposure while still maintaining appropriate safety monitoring and integrity 
of the study data. These prospective deviations (e.g., window extensions) are described in the 
Schedule of Events (Section 15). These measures are temporary and will be repealed as soon as 
the situation (e.g., governmental rules, benefit/risk assessment for the trial) allows. 
All deviations will be logged and tracked by the site and CRO. Periodic review of protocol 
deviations will serve as an indicator of site performance. 
It is the responsibility of the site to use continuous vigilance to identify and report deviations 
promptly to the study CRO and/or Sponsor. All deviations must be addressed in study source 
documents. Notification of protocol deviations must be sent to the local IRB/IEC per their 
guidelines. The site investigator/study staff is responsible for knowing and adhering to their 
IRB/IEC requirements. 
13.4. Publication and Data Sharing Policy 
In compliance with The International Committee of Medical Journal Editors clinical trials 
registration policy and Section 801 of the FDA Amendments Act of 2007, this study will be 
registered by the Sponsor in ClinicalTrials.gov, a public trials registry which is sponsored by the 
National Library of Medicine. 
Notwithstanding the Sponsor’s requirements for registration and data sharing in 
ClinicalTrials.gov, any formal presentation or publication of data collected as a direct or indirect 
result of this trial will be considered as a joint publication by the investigator(s) and the Sponsor. 
In the case of multicenter studies, it is mandatory that the first publication be made based on the 
totality of data obtained from all centers, analyzed as stipulated in the protocol, and presented 
and interpreted as documented in the final clinical study report (CSR). The resulting publication 
will name investigators according to the policy of the chosen journal. Where it is not permitted 


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for all investigators to be included as authors, the publication will name all investigators within 
the publication. 
Individual investigators may publish data arising from their own participants. The investigator 
will provide the Sponsor with copies of written publications (including abstracts and posters) at 
least 60 days in advance of submission. This review is to permit the Sponsor to review the 
communication for accuracy (thus avoiding potential discrepancies with submissions to 
regulatory authorities), to verify that confidential information is not inadvertently divulged 
(including patent protection), to allow adequate input or supplementary information that may not 
have been available to the investigator, and to allow establishment of co-authorship. 
Investigators participating in multicenter studies must agree not to engage in presentations based 
on data gathered individually or by a subgroup of centers before publication of the first main 
publication unless this has been agreed otherwise by all other investigators and the Sponsor. 
However, in the event that no publication of the overall results has been submitted after approval 
of the CSR, investigators may publish results of one or more center’s participants to the same 
review as outlined above. The Sponsor will circulate proposed multicenter publications to all 
investigators for review. 
Data will be reviewed by all participating investigators prior to publication. The study Sponsor 
will have 90 days to review all definitive publications, such as manuscripts and book chapters, 
and a minimum of 30 days to review all abstracts. 


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14. 
FINANCIAL DISCLOSURE AND CONFLICT OF INTEREST POLICY 
A separate financial disclosure agreement will be made between each principal investigator and 
Alkahest, Inc. or its authorized representative before the study agent is shipped. Each 
investigator will notify Alkahest, Inc. or its authorized representative of any relevant changes 
during the conduct of the study and for 1 year after the study has been completed. Alkahest and 
the study CRO will evaluate any disclosed conflicts of interest and will establish a mechanism 
for their management. 
 


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15. 
SCHEDULE OF EVENTS 
Table 2 
Schedule of Assessments 
 
Screening 
Treatment 
Follow-up 
Visit Number 
1 
2 (Baseline) 
3 
4 
5 
6 
7 
8 (EOT/ET)b 
9 (EOS) 
Week 
 
1 
4 
8 
12 
16 
20 
24 
28 
Day 
-28 to -2 
1 
28 
56 
84 
112 
140 
168 
196 
Time Window (days)a 
 
 
±3 
±3 
±3 
±3 
±3 
±3 
±3 
Informed consent and optional consent for 
aqueous humor sample collectionc 
X 
 
 
 
 
 
 
 
 
Informed consent for DNA bankingd 
X 
 
 
 
 
 
 
 
 
Demographics 
X 
 
 
 
 
 
 
 
 
Medical history 
X 
 
 
 
 
 
 
 
 
Inclusion/exclusion criteriae 
X 
X 
 
 
 
 
 
 
 
Physical examination 
X 
X 
 
 
 
 
 
X 
 
Vital signs (seated) 
X 
X 
X 
X 
X 
X 
X 
X 
 
Pregnancy test (in WOCBP)f 
X 
X 
X 
X 
X 
X 
X 
X 
 
Laboratory testsg 
X 
X 
X 
X 
X 
X 
X 
X 
X 
12-lead electrocardiogram 
X 
 
 
 
 
 
 
X 
X 
HbA1c 
  
X 
 
 
X 
 
 
X 
 
Extended ophthalmoscopy 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Slit lamp examination 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Intraocular pressure 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Gonioscopy  
X 
X 
 
X 
 
X 
 
X 
X 
SD-OCT 
X 
X 
X 
X 
X 
X 
X 
X 
X 
OCT-A (if available at the site)h 
 
X 
 
 
 
 
 
X 
 
Visual acuityi 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Fundus photography 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Fluorescein angiographyj 
X 
 
 
 
X 
 
 
X 
 
VF with perimetry and/or microperimetry (if 
available at the site)h 
 
X 
 
 
 
 
 
X 
 
Workplace Productivity and Activity 
Impairment General Health questionnaire 
 
X 
 
X 
 
X 
 
X 
 
Administration of study agentk 
 
X 
X 
X 
X 
X 
X 
X 
 
Dispense study agent 
 
X 
X 
X 
X 
X 
X 
 
 
Study agent accountability 
 
X 
X 
X 
X 
X 
X 
X 
 


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Screening 
Treatment 
Follow-up 
Visit Number 
1 
2 (Baseline) 
3 
4 
5 
6 
7 
8 (EOT/ET)b 
9 (EOS) 
Week 
 
1 
4 
8 
12 
16 
20 
24 
28 
Day 
-28 to -2 
1 
28 
56 
84 
112 
140 
168 
196 
Time Window (days)a 
 
 
±3 
±3 
±3 
±3 
±3 
±3 
±3 
Optional aqueous humor collection1 
 
X 
 
 
 
 
 
X 
 
PK blood sample collection (for plasma 
extraction)m 
 
X 
X 
X 
X 
X 
X 
X 
X 
Biomarker plasma aliquotsm 
 
X 
 
 
 
 
 
X 
X 
Pharmacogenomics blood sample (and 
optional DNA banking sample) 
 
Xd 
 
 
 
 
 
 
 
Flow cytometry/CBC blood sample 
collectionm 
 
X 
 
 
 
 
 
X 
 
Prior and concomitant medication reviewn 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Adverse events 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Study completion 
 
 
 
 
 
 
 
 
X 
Abbreviations: ASNV = anterior-segment neovascularization; BCVA = best corrected visual acuity; CBC = complete blood count; CI-DME = center-involved 
diabetic macular edema; EOS = end of study; EOT = end of treatment; ET = early termination; ETDRS = Early Treatment Diabetic Retinopathy Study; 
HbA1c = hemoglobin A1c; OCT-A = optical coherence tomography angiography; PDR = proliferative diabetic retinopathy; PK = pharmacokinetic; SD-OCT= 
spectral domain optical coherence tomography; VF = visual field; WOCBP = women of childbearing potential 
Notes: 
a. Window extensions and missed protocol assessments may be permitted to reduce the risk of COVID-19 exposure. Any deviation to the protocol to 
reduce the risk of COVID-19 exposure will be captured as a “Protocol Deviation related to COVID-19” to categorize the anticipated increase in protocol 
deviations due to the pandemic. These measures are temporary and will be repealed as soon as the situation (e.g., governmental rules, benefit/risk 
assessment for the trial, etc.) allows (see Section 13.3). 
b. Visit 8 (EOT/ET): all study related procedures will be conducted at the conclusion of treatment on Day 168±3. Withdrawal of consent is allowed at any 
time. For ET participants, the EOT visit procedures should be conducted at the time of ET, in place of the next scheduled treatment visit. For participants 
who withdraw consent from the study, no additional study procedures will be performed. 
c. All participants must sign an informed consent consistent with ICH-GCP guidelines prior to any trial related procedures, which includes medication 
washouts and restrictions. An optional consent for aqueous humor testing will also be provided. 
d. Informed consents must be obtained for optional DNA banking. DNA banking will be optionally collected at the time of enrollment (Visit 2 [Baseline]). 
e. A preliminary check of inclusion/exclusion criteria will be performed at Visit 1 (Screening) after obtaining informed consents. 
f. Pregnancy testing may be performed using serum or urine. Tests should be performed at the site and results reviewed. Positive pregnancy test results 
should be confirmed with a serum pregnancy test performed by the central laboratory. 
g. Hematology, clinical chemistry, and urinalysis. Additionally, serology testing will be performed at Visit 1 (Screening) only. 
h. For sites with the capability to perform OCT-A and VF, these assessments should be performed at Visit 2 (Baseline) and Visit 8 (EOT/ET). 
i. Visual acuity assessments will include BCVA as assessed using the ETDRS method. 
j. Fundus photography and fluorescein angiogram must be performed once a participant has been diagnosed with CI-DME or PDR, and before rescue 
treatment is given. 
k. Study drug will be self-administered in the clinic under the supervision of study personnel during every in-clinic visit of the Treatment Period (Visits 2-8) 


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Screening 
Treatment 
Follow-up 
Visit Number 
1 
2 (Baseline) 
3 
4 
5 
6 
7 
8 (EOT/ET)b 
9 (EOS) 
Week 
 
1 
4 
8 
12 
16 
20 
24 
28 
Day 
-28 to -2 
1 
28 
56 
84 
112 
140 
168 
196 
Time Window (days)a 
 
 
±3 
±3 
±3 
±3 
±3 
±3 
±3 
after any pre-dose assessments (including PK sample collection), and then self-administered at home between study visits. Training on study drug 
administration will be conducted prior to the initial study drug administration at Visit 2.  
l. If a participant requires treatment for a vision-threatening complication, the aqueous humor collection will occur prior to treatment. 
m. A PK blood sample will be collected and then centrifuged for collection of plasma samples. A blood sample for biomarkeranalysis will be collected and 
then centrifuged for collection of  plasma samples. At Visits 2 and 4, 1 post-dose PK blood sample will be collected. At Visit 2 only, 1 post-dose flow 
cytometry/CBC sample will be collected. The PK, biomarker, pharmacogenomic, and flow cytometry/CBC sampling schedule is presented in Table 3.  
n. While unlikely to happen, it is possible that AKST4290 may reduce the plasma concentrations 
 
therefore, clinical and/or laboratory monitoring for loss of efficacy may be required for participants taking these medications (also see 
Section 17.3.2). 
 
 


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16. 
REFERENCES 
16.1. Published References 
American Academy of Ophthalmology (AAO). Diabetic retinopathy preferred practice pattern. 
2019. Available at: http://dx.doi.org/10.1016/j.ophtha.2019.09.025. Accessed November 21, 
2020. 
Brown DM, Schmidt-Erfurth U, Do DV, Holz FG, Boyer DS, Midena E, et al. Intravitreal 
aflibercept for diabetic macular edema: 100-week results from the VISTA and VIVID studies. 
Ophthalmology. 2015;122:2044-2052. 
Centers for Disease Control (CDC) and Prevention. National Diabetes and Statistics Report 
2020. 
Clinical Trial Facilitation Group. Recommendations related to contraception and pregnancy 
testing in clinical trials. Version 2014-09-15:1-13. 
Diabetic Retinopathy Clinical Research Network (DRCRN). Randomized trial evaluating 
ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic 
macular edema. Ophthalmology. 2010;117:1064-1077. 
Diabetic Retinopathy Clinical Research Network (DRCRN). Randomized trial evaluating short-
term effects of intravitreal ranibizumab or triamcinolone acetonide on macular edema following 
focal/grid laser for diabetic macular edema in dyes also receiving panretinal photocoagulation. 
Retina. 2011;31:1009-1027. 
Diabetic Retinopathy Study (DRS) Research Group. Preliminary report on effects of 
photocoagulation therapy. Am J Ophthalmol. 1976;81:383-396. 
Duh EJ, Sun JK, Stitt AW. Diabetic retinopathy: current understanding, mechanisms, and 
treatment strategies. JCI Insight. 2017;2(14):e93751. 
Early Treatment Diabetic Retinopathy Study Research (ETDRS) Group. Early photocoagulation 
for diabetic retinopathy. ETDRS report number 9. Ophthalmology. 1991a;98:766-785. 
Early Treatment Diabetic Retinopathy Study Research (ETDRS) Group. Fundus photographic 
risk factors for progression of diabetic retinopathy. ETDRS report number 12. Ophthalmology. 
1991b;98:823-833. 
EYLEA Full Prescribing Information. Regeneron Pharmaceuticals, Inc., 2019. 
Food and Drug Administration (FDA), U.S. Department of Health and Human Services. 
Guidance for Industry and Investigators: Safety Reporting Requirements for INDs and BA/BE 
Studies. December, 2012. 


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International Diabetes Federation (IDF). IDF Diabetes Atlas, Ninth Edition, 2019. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
NCT02718326. Study of the Efficacy and Safety of Intravitreal (IVT) Aflibercept for the 
Improvement of Moderately Severe to Severe Nonproliferative Diabetic Retinopathy (NPDR) 
(PANORAMA). Available at: https://clinicaltrials.gov/ct2/show/results/NCT02718326. 
Accessed February 7, 2021. 
Nguyen QD, Brown DM, Marcus DM, Boyer DS, Patel S, Feiner L, et al. Ranibizumab for 
diabetic macular edema; results from 2 Phase III randomized trials: RISE and RIDE. 
Ophthalmology. 2012;119:789-801. 
 
 


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Reddy SV, Husain D. Panretinal photocoagulation: a review of complications. Sem Ophthalmol. 
2018;33:83-88. 
Solomon SD, Chew E, Duh EJ, Sobrin L, Sun JK, VanderBeek BL, et al. Diabetic retinopathy: a 
position statement by the American Diabetes Association. Diabetes Care. 2017;40:412-418. 
Staurenghi G, Feltgen N, Arnold JJ, et al. Impact of baseline Diabetic Retinopathy Severity Scale 
scores on visual outcomes in the VIVID-DME and VISTA-DME studies. Br J Ophthalmol. 
2018;102:954–958. 
 
 
 
 
 
Wang W, Lo ACY. Diabetic retinopathy: pathophysiology and treatments. Int J Molec. Sci. 
2018;19:1816. 
 
Wykoff CC, Eichenbaum DA, Roth DB, Hill L, Fung AE, Haskova Z. Ranibizumab induces 
regression of diabetic retinopathy in most patients at high risk of progression to proliferative 
diabetic retinopathy. Ophthalmol Retina. 2018;2:997-1009. 
Zhang et al. Arthritis Research & Therapy 2010, 12:R177 http://arthritis-
research.com/content/12/5/R177 Validity of the work productivity and activity impairment 
questionnaire - general health version in patients with rheumatoid arthritis  
16.2. Unpublished References 
 
 
 
 
 
 
 


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17. 
APPENDICES 
17.1. Clinical Evaluation of Liver Injury 
17.1.1. 
Introduction 
Clinically significant alteration of liver laboratory parameters, as described in Sections 8.2.1 
and 8.4.3 (protocol-specified AESI), are to be further evaluated and followed using the 
procedures described in the subsequent sections. 
17.1.2. 
Procedures 
17.1.2.1. 
Guidelines for Evaluation and Follow-up Testing of Mild Liver Enzyme 
Elevations 
Guidelines for evaluation and follow-up testing of mild liver enzyme elevations (ALT or AST 
≥ 3× ULN but < 5× ULN without bilirubin elevations) include: 
• A review of symptoms, history, and physical examination to assess for signs of liver enzyme 
elevation etiology, and updates to the CRF should be made as appropriate (see 
Section 17.1.3). 
• Repeat ALT, AST, bilirubin, and ALP testing, and perform initial gamma-glutamyl 
transferase (GGT) testing, within 1 week with the central laboratory to confirm the results.  
○ In cases in which the central laboratory is not immediately available (e.g., if the logistics 
are such that the participant´s repeat specimen would not reach the central laboratory in a 
reasonable timeframe), ALT, AST, and bilirubin (total and direct) will be evaluated by 
the local laboratory and results will be made available to the investigator and to Alkahest 
as soon as possible.  
• If elevations are confirmed on repeat testing, follow-up testing of ALT, AST, bilirubin, ALP, 
and GGT should be repeated at a minimum of every 2 weeks until ALT and AST values have 
decreased to < 2× ULN.  
• Once values reach < 2× ULN, standard per protocol laboratory assessment is adequate. 
17.1.2.2. 
Guidelines for Evaluation and Follow-up Testing of Moderate to Severe 
Liver Enzyme Elevations 
Guidelines for evaluation and follow-up testing of moderate (ALT or AST ≥ 5× ULN without 
bilirubin elevations) to severe (ALT or AST ≥ 3× ULN with an elevation of total bilirubin 
> 2× ULN) liver enzyme elevations include: 
• A review of symptoms, history, and physical examination findings to assess for signs of liver 
enzyme elevation etiology, and updates to the CRF should be made as appropriate (see 
Section 17.1.3). 


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• Repeat ALT, AST, bilirubin, and ALP testing, and perform initial GGT testing, within 
48-72 hours with the central laboratory to confirm the results.  
○ In cases in which the central laboratory is not immediately available (e.g., if the logistics 
are such that the participant´s repeat specimen would not reach the central laboratory in a 
reasonable timeframe), ALT, AST, and bilirubin (total and direct) will be evaluated by 
the local laboratory and results will be made available to the investigator and to Alkahest 
as soon as possible.  
• If confirmed on repeat testing, close observation should be initiated, follow-up testing of 
ALT, AST, bilirubin, ALP, and GGT should be repeated weekly until resolved, and 
additional one-time tests should be obtained as described in Sections 17.1.2.3 through 
17.1.2.8, in consultation with the Medical Monitor. 
• Once values reach < 2× ULN, standard per protocol laboratory assessment is adequate.  
17.1.2.3. 
Clinical Chemistry 
• Obtain albumin, PT or INR, creatinine kinase, creatinine kinase MB test (CK-MB), 
ceruloplasmin, α-1 antitrypsin, transferrin, amylase, lipase, glucose, cholesterol, and 
triglycerides. 
17.1.2.4. 
Serology 
• Obtain hepatitis A (anti-immunoglobulin M [IgM], anti-IGM), hepatitis B (hepatitis B 
antigen, anti-HBs, DNA), hepatitis C (anti- HCV), ribonucleic acid (RNA) if anti-HCV 
positive), hepatitis E (anti-hepatitis E virus [HEV]), anti-HEV IgM, RNA (if anti-HEV IgM 
positive), anti-smooth muscle antibody (titer), anti-nuclear antibody (titer), anti-liver-kidney 
microsomes  antibody, antimitochondrial antibody, Epstein Barr virus (viral capsid antigen 
IgM), cytomegalovirus (IgM), herpes simplex virus (IgM), varicella (IgM), parvovirus 
(IgM), toxoplasmosis (IgM), total serum (IgG). 
17.1.2.5. 
Hormones 
• Thyroid-stimulating hormone. 
17.1.2.6. 
Hematology and Coagulation 
• CBC with differential. 
17.1.2.7. 
Ultrasound 
• Perform an abdominal ultrasound to assess for cirrhosis, non-perfusion, biliary tract, 
pancreatic, or intrahepatic pathology (e.g., bile duct stones or neoplasm). 
17.1.2.8. 
Consultation 
• Consider hepatology or general gastrointestinal consultation. 


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17.1.3. 
Case Report Form Guidelines 
For all liver enzyme abnormalities (mild, moderate, severe), the following should be reported in 
the CRF: 
• Detailed history of current symptoms, concurrent diagnoses, and medical history according 
to the DILI Checklist provided in the ISF. 
• History of concomitant drug use (including non-prescription medications, herbal and dietary 
supplement preparations), alcohol use, recreational drug use, and special diets according to 
the DILI Checklist provided in the ISF. 
• History of exposure to environmental chemical agents (consider home and workplace 
exposure) according to the DILI Checklist provided in the ISF. 
17.2. Modification of Diet in Renal Disease Formula 
When serum creatinine is in mg/dL (conventional units), the GFR may be estimated based on the 
following MDRD formula: 
GFR (mL/min/1.73 m2) = 186 × (serum creatinine)–1.154 × (Age[years])–0.203 × (0.742 if 
female) × (1.210 if African American) 
When serum creatinine is in μmol/L (SI units) the GFR may be estimated based on the following 
MDRD formula: 
GFR (mL/min/1.73 m2) = 186 × (serum creatinine/88.4)–1.154 × (Age [years])–0.203 × 
(0.742 if female) × (1.210 if African American) 
 


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17.3. List of Prohibited Medications and Substances 
 
 
 
  
 
 
 
 
 


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17.4. Pharmacokinetic, Biomarker, Pharmacogenomic, and Flow Cytometry/CBC 
Sampling 
The PK, biomarker, pharmacogenomic, and flow cytometry/CBC sampling schedule is presented 
in Table 3. 
Table 3 
Pharmacokinetic, Biomarker, Pharmacogenomic, and Flow 
Cytometry/CBC Sampling Schedule 
Visit 
Time Point 
Time for 
Database 
Setup 
PK 
Blood 
Sample 
Extra 
Biomarker 
Aliquot from 
PK Blood 
Sample 
Pharmacogenomic 
Blood Sample 
Flow 
Cytometry/CBC 
2 
Prior to (i.e., within 30 
min before study agent 
administration) 
-0:15 h 
X 
X 
X 
X 
0:00 (study agent 
administration) 
0:00 h 
 
 
 
 
1:00 ± 30 minutes 
1:00 h 
X 
X 
 
X 
3 
-00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0:00 h 
X 
 
 
 
4 
--00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0 
X 
 
 
 
1:00 ± 30 minutes 
1:00 h 
X 
 
 
 
5 
-00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0:00 h 
X 
 
 
 
6 
-00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0:00 h 
X 
 
 
 
7 
-00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0:00 h 
X 
 
 
 
8 
-00.45 to -00:15 min 
(i.e., within 30 min 
before study agent 
administration) 
0:00 h 
X 
X 
 
X 
9 
 
Any time during visit 
0:00 h 
X 
X 
 
 
Abbreviations: CBC = complete blood count; h = hour(s); min = minute(s); PK = pharmacokinetic 
 
 


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17.5. Work Productivity and Activity Impairment Questionnaire: General Health 
The WPAI-GH V2.0 is a 6-question survey used to assess the effects of a participant’s health 
problems (i.e., physical or emotional problems or symptoms) on their ability to work and 
perform regular activities during the past 7 days. In clinical trials, the WPAI-GH has been used 
to compare work impairments between treatment groups in participants with varying levels of 
disease severity (Zhang 2010). The questionnaire below is provided as an EXAMPLE ONLY. 
The actual assessment and instructions for administration and scoring will be included in a rater 
reference manual or equivalent. 
 
 


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18. 
REVISION HISTORY 
18.1. Summary of Changes 
 
Protocol Version 2.0 dated 19AUG2021 
Replaces: Protocol Version 1.0 dated 08APR2021 
 
The following table describes changes from Version 1.0 (dated 08APR2021) with justifications 
provided. 
 
Section 
Description 
Justification 
Throughout 
Protocol version update.  
Previously read:  V1.0_08APR2021 
 
Now reads: V2.0_18AUG2021 
Version control. 
Throughout 
Minor grammar, content, and style updates.  
Minor content updates for 
clarity/accuracy/style of content. 
Table of 
Contents 
Minor content updates. 
Minor updates required to reflect 
revised content. 
List of 
Abbreviations 
Minor content updates. 
Minor updates required for accuracy 
and to reflect revised content. 
Protocol 
Summary, 3.3, 
4.2.3, 7.2.2.3, 
15 (Schedule of 
Assessments); 
17.4 
Removed fluorescence-activated cell sorting 
(FACS) and replaced with flow cytometry. 
Clarification of terminology of 
evaluation. 
Protocol 
Summary, 3.3, 
4.2.3, 10.4.4 
Modified the exploratory objective and 
endpoint for assessment of change from 
Baseline over time in BCVA using the 
ETDRS method to define the change from 
Baseline as either gains or losses. Removed 
the duplicate objective and associated 
endpoint. 
Minor update for accuracy and clarity. 
Protocol 
Summary, 4.2.3 
Modified the exploratory endpoint for 
change in area of ischemia or area of 
neovascularization from Baseline over time 
to allow for the assessment to be completed 
using OCT-A and/or FA. 
Clarification of the modality for 
assessment of the endpoint.  
4.1, 7.1.1.1, 
7.1.1.2, 
7.1.1.3.4, 15 
Changed term from indirect ophthalmoscopy 
to extended ophthalmoscopy. 
Administrative clarification. 
5.1 
 
 
 
 
 
 
Updated the window for previous 
treatment for ease of enrollment. 


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5.1 and 5.2 
Exclusion Criterion 3, part c was modified 
and moved to become Inclusion Criterion 7 
as follows: 
Previously read: In addition, the investigator 
and potential participant are comfortable 
withholding treatment for DME until there is 
at least a 10% increase in OCT central 
subfield thickness with confirmed visual 
acuity loss (10 letter loss at a single visit or 5 
to 9 letters at 2 consecutive visits) 
Now reads:  The investigator and potential 
participant are comfortable withholding 
treatment for DME and PDR until protocol-
defined treatment criteria are met (see 
Section 5.4). 
Revised for clarity. 
5.2 
Exclusion Criterion 4 was modified to 
stipulate a treatment window as follows: 
Previously read: Prior intraocular or 
periocular steroid injection.  
Now reads: Prior intraocular or periocular 
steroid injection within 12 months prior to 
enrollment and assignment to a randomized 
treatment. 
Revised to add a window for prior 
treatment. 
5.2 
 
 
Content added based on regulatory 
feedback. 
5.4 
Section 5.4 added to detail the threshold for 
treatment of CI-DME 
Content added for clarity on the 
treatment requirements for the 
occurrence of CI-DME. 
6.2 
Previously read:  
The disposal of used, partially used, or 
wasted AKST4290 and/or placebo must be 
performed in accordance with the 
institution’s drug disposal policy. 
Now reads: 
The disposal of used, partially used, or 
wasted AKST4290 and/or placebo must be 
performed in accordance with the 
institution’s drug disposal policy or return. 
Clarification of drug return 
procedures. 
7.1.1.2.6 
Updated the list of chemistry assessments to 
include eGFR and removed eGFR from the 
list of urinalysis assessments. 
Correction as eGFR is calculated from 
serum creatinine and is not a 
urinalysis assessment. 
7.5 
The restriction advising participants to avoid 
alcoholic beverages from 48 hours before 
study drug administration through the EOS 
examination was removed. 
Text was removed as alcohol is not 
considered a prohibited drug. 
7.5, 17.3, 
17.3.1, and 
17.3.3 
 
 
 
 
 
Content added based on regulatory 
feedback. 


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15, Schedule of 
Assessments 
• 
Switched the order of assessments for 
Optional aqueous humor collection and 
PK blood sample collection for proper 
footnote ordering. 
• 
Corrected the footnote letter from “l” to 
“m” for the rows labeled as “PK blood 
sample collection (for plasma 
extraction)” and “Biomarker plasma 
aliquot”. 
• 
Clarified footnote “m” to indicate that 
PK blood samples and samples for 
biomarker analysis are collected in 
separate tubes. 
• 
Removed visual field assessment at 
Visit 9. 
Minor changes for clarity and to 
remove an assessment that is not 
required at the End-of-Study visit. 

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STATISTICAL ANALYSIS PLAN 
Alkahest, Inc. 
AKST4290-231 
 
 
 
 
 
 
Protocol Title: 
A Double-Masked, Placebo-Controlled Study to Evaluate the 
Efficacy of Oral AKST4290 in Participants with Moderately 
Severe to Severe Diabetic Retinopathy (CAPRI) 
Protocol Version 
and Date: 
Version: 2.0; 19 August 2021 
Sponsor: 
Alkahest, Inc. 
125 Shoreway Road, Suite D  
San Carlos, CA 94070 
Prepared By: 
Document 
Version and Date 
Version 1.0; 02 June 2022 
 
 


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STATISTICAL ANALYSIS PLAN APPROVAL 
Sponsor: 
Alkahest, Inc. 
Clinical Protocol Number: AKST4290-231 
Protocol Title: 
A Double-Masked, Placebo-Controlled Study to 
Evaluate the Efficacy of Oral AKST4290 in 
Participants with Moderately Severe to Severe 
Diabetic Retinopathy (CAPRI) 
Document File and Name: 
Alkahest_AKST4290-231_SAP_v1.0_2022-06-
02.pdf 
Document Version and 
Effective Date: 
Version 1.0; 02 June 2022 
Approved By: 
 
 
 


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TABLE OF CONTENTS 
 
STATISTICAL ANALYSIS PLAN APPROVAL ........................................................ 2 
TABLE OF CONTENTS ............................................................................................... 3 
TABLE OF TABLES .................................................................................................... 5 
TABLE OF FIGURES ................................................................................................... 5 
ABBREVIATIONS ....................................................................................................... 6 
1. 
INTRODUCTION ................................................................................................. 8 
2. 
STUDY OBJECTIVES .......................................................................................... 8 
2.1 
Primary Study Objective ................................................................................. 8 
2.2 
Secondary Study Objectives............................................................................ 8 
2.3 
Exploratory Study Objectives ......................................................................... 9 
3. 
INVESTIGATIONAL PLAN ................................................................................ 9 
3.1 
Overall Study Design ...................................................................................... 9 
3.2 
Schedule of Assessments .............................................................................. 10 
3.3 
Treatment ...................................................................................................... 10 
3.3.1 
Treatment Administered ........................................................................ 11 
3.3.2 
Method of Assigning Subjects to Treatment Groups ............................. 11 
3.3.3 
Masking Procedures ............................................................................... 11 
3.4 
Efficacy and Safety Variables ....................................................................... 11 
3.4.1 
Efficacy Variables .................................................................................. 12 
3.4.2 
Safety Variables ..................................................................................... 14 
3.4.3 
Pharmacokinetic Variables .................................................................... 16 
3.5 
Data Quality Assurance ................................................................................. 16 
4. 
STATISTICAL METHODS ................................................................................ 17 
4.1 
General Methodology .................................................................................... 17 
4.1.1 
Reporting Conventions .......................................................................... 17 
4.1.2 
Summarization by Visit ......................................................................... 17 
4.1.3 
Data Handling Rules .............................................................................. 17 
4.1.4 
Standard Calculations ............................................................................ 17 
4.2 
Study Subjects ............................................................................................... 18 
4.2.1 
Disposition of Subjects .......................................................................... 18 
4.2.2 
Protocol Deviations ................................................................................ 18 
4.2.3 
Plasma Concentrations ........................................................................... 18 
4.2.4 
Pharmacokinetic Analysis ...................................................................... 18 
4.3 
Efficacy Evaluations ..................................................................................... 18 
4.3.1 
Demographic and Other Baseline Characteristics ................................. 19 
4.3.2 
Measurements of Treatment Compliance .............................................. 19 


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4.3.3 
Efficacy Endpoint Analysis ................................................................... 19 
4.4 
Safety Evaluation .......................................................................................... 20 
4.4.1 
Extent of Exposure ................................................................................. 20 
4.4.2 
Adverse Events ...................................................................................... 20 
4.4.3 
Deaths, Other Serious Adverse Events, and Other Significant Adverse 
Events 20 
4.4.4 
Clinical Laboratory Evaluation .............................................................. 21 
4.4.5 
Vital Signs, Physical Findings, and Other Observations Related to 
Safety 21 
4.5 
Determination of Sample Size....................................................................... 22 
4.6 
Changes in the Conduct of the Study or Planned Analyses .......................... 23 
5. 
REFERENCE LIST ............................................................................................. 23 
 
 
 


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TABLE OF TABLES 
Table 1 
List of Abbreviations ................................................................................... 6 
 
TABLE OF FIGURES 
Figure 1 
Study Flow Diagram .................................................................................. 10 
 
 


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ABBREVIATIONS 
Table 1 
List of Abbreviations 
Abbreviation 
Definition 
AE 
Adverse event 
AESI 
Adverse event of special interest 
ALT 
Alanine aminotransferase 
ASNV 
Anterior-segment neovascularization 
AST 
Aspartate aminotransferase 
ATC  
Anatomical Therapeutic Chemical 
AUC 
Area under the curve 
BUN 
Blood urea nitrogen 
CBC 
Complete blood count 
CI-DME 
Center-involved diabetic macular edema 
CMT 
Central macular thickness 
CSR 
Clinical Study Report 
DILI 
Drug-induced liver injury 
DM 
Diabetes mellitus 
DR 
Diabetic retinopathy 
DRSS 
Diabetic Retinopathy Severity Scale 
DSMB 
Data and Safety Monitoring Board 
ECG 
Electrocardiogram 
eCRF 
Electronic case report form 
EDC 
Electronic data capture 
eGFR 
Estimated glomerular filtration rate 
ENT 
Ears, nose, and throat 
EOT 
End of Treatment 
EOS 
End of Study 
ET 
Early Termination 
ETDRS 
Early Treatment Diabetic Retinopathy Study  
FA 
Fluorescein angiography 
FP-4W 
Fundus Photography 4 Wide 
FP-7M 
Fundus Photography Modified 7 Field 
FP 
Fundus photography 
HbA1c 
Hemoglobin A1c 
HBV 
Hepatitis B virus 
HCV 
Hepatitis C virus 
HIV 
Human immunodeficiency virus 
ICH 
International Council for Harmonisation 
IOP 
Intraocular pressure 
IL 
Interleukin 
LPLV 
Last participant, last visit 


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Abbreviation 
Definition 
MedDRA 
Medical Dictionary for Regulatory Activities 
NPDR 
Nonproliferative diabetic retinopathy 
OCT-A 
Optical coherence tomography angiography 
OD 
Oculus dexter 
OS 
Oculus sinister 
PDR 
Proliferative diabetic retinopathy 
PK 
Pharmacokinetics 
PT 
Prothrombin time 
PTT 
Partial thromboplastin time 
QTc 
QT interval corrected for heart rate 
QTcF 
QT interval corrected for heart rate using Fridericia’s 
correction formula 
SAE 
Serious adverse event 
SAP 
Statistical Analysis Plan 
SD-OCT 
Spectral domain optical coherence tomography 
SI 
Système International 
TEAE 
Treatment-emergent adverse event 
TNF-α 
Tumor necrosis factor-alpha 
UACR 
Urine albumin to creatinine ratio 
ULN 
Upper limit of normal 
VF 
Visual field 
WHODDE 
World Health Organization Drug Dictionary Enhanced 
WPAI-GH 
Workplace Productivity and Activity Impairment General 
Health 
 
 


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1. INTRODUCTION 
The purpose of this Statistical Analysis Plan (SAP) is to provide comprehensive and 
detailed descriptions of the methods and presentation of data analyses proposed for 
Alkahest, Inc. Protocol AKST4290-231 (A Double-Masked, Placebo-Controlled Study 
to Evaluate the Efficacy of Oral AKST4290 in Participants with Moderately Severe to 
Severe Diabetic Retinopathy [CAPRI]). Descriptions of planned analyses are provided 
in order to avoid post hoc decisions that may affect the interpretation of the statistical 
analysis. The statistical methods applied in the design and planned analyses of this 
study are consistent with the International Council for Harmonisation (ICH) guidelines 
Statistical Principles for Clinical Trials (E9) (1998) and Statistical Principles for 
Clinical Trials: Addendum: Estimands and Sensitivity Analysis in Clinical Trials 
(E9[R1]) (2017).  
This SAP will be finalized prior to data analysis and before treatment unmasking and 
database lock to provide comprehensive details of the listings to be presented in the 
Clinical Study Report (CSR). Any changes between the statistical methods provided in 
the clinical study protocol and this SAP will be explained herein; any changes or 
deviations from this SAP relative to the final analysis will be fully documented in the 
CSR. Minor changes or deviations from the templates for provided listings need not be 
documented in the CSR. 
On 09Dec2021, study investigators were notified the AKST4290-231 study was being 
terminated. Safety findings related to liver enzyme elevations were discovered in other 
AKST4290 studies. Out of an abundance of caution, active study participants were 
required to discontinue study drug and new enrollment was discontinued. Three study 
participants were randomized and taking study drug at the time of this notification. This 
SAP has been modified to accommodate the limited number participants enrolled in 
this prematurely concluded study.  
2. STUDY OBJECTIVES 
2.1 
Primary Study Objective 
The primary objective of this study is to investigate the efficacy of AKST4290. 
2.2 
Secondary Study Objectives 
The secondary objectives of this study are: 
• To investigate additional measures of efficacy of AKST4290; 
• To assess the proportion of participants progressing to (or worsening of) center-
involved diabetic macular edema (CI-DME), proliferative diabetic retinopathy 
(PDR), and/or anterior-segment neovascularization (ASNV); 
• To assess the time to event of CI-DME, PDR, and/or ASNV requiring treatment; 
• To assess the overall safety of AKST4290; 
• To assess the effect of AKST4290 on diabetic kidney disease; 


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• To evaluate the changes from Baseline in the Workplace Productivity and 
Activity Impairment General Health (WPAI-GH) questionnaire. 
2.3 
Exploratory Study Objectives 
The exploratory objectives of this study are: 
• To assess the mean change from Baseline (gain or loss) in BCVA; 
• To assess the mean change from Baseline in macular volume and central 
macular thickness (CMT); 
• To assess the proportion of participants with worsening of Diabetic Retinopathy 
Severity Scale (DRSS) score; 
• To assess visual acuity area under the curve (AUC); 
• To investigate the impact of AKST4290 when administered at doses of 400 mg 
b.i.d. 
on 
pharmacokinetics 
(PK), 
pharmacogenomic, 
and 
flow 
cytometry/complete blood count (CBC) evaluations of interest conducted on 
blood and plasma samples; 
• To evaluate changes from Baseline in optical coherence tomography 
angiography (OCT-A) (as available at sites); 
• To evaluate changes from Baseline in visual field (VF) as assessed by 
perimetry/microperimetry evaluations (as available at sites); 
• To evaluate the change from Baseline over time and the presence of 
inflammatory biomarkers 
 
n aqueous humor collected from participants who 
elect to provide these samples. 
3. INVESTIGATIONAL PLAN 
3.1 
Overall Study Design 
This is a Phase 2, double-masked, placebo-controlled multicenter study to evaluate the 
efficacy of AKST4290 administered at an 800 mg daily dose (400 mg b.i.d.) as 
compared with placebo over a 24-week dosing period in participants with moderately 
severe nonproliferative diabetic retinopathy (NPDR) (DRSS Level 47) to severe NPDR 
(DRSS Level 53) in one eye, and at least mild NPDR (DRSS Level 35) to mild PDR 
(DRSS Level 61) in the other eye. Both eyes must not have CI-DME, and must have 
good vision (defined as BCVA of ≥ 69 letters using the Early Treatment Diabetic 
Retinopathy Study [ETDRS] method). 
Eligible participants will be enrolled into one of two randomized treatment arms (active 
and placebo) in a 2:1 fashion of active to placebo. Participants will receive treatment 
for a total of 24 weeks with either AKST4290 800 mg daily (400 mg b.i.d.) in Arm 1 
or placebo (matching tablets) in Arm 2. 


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Once enrolled and allocated to a randomized treatment, all participants will be 
evaluated monthly throughout the treatment period (ie, at Visits 2, 3, 4, 5, 6, 7, and 8) 
to assess efficacy and monitor safety for the development of the vision-threatening 
complications of CI-DME, PDR, and/or ASNV. Participants who develop CI-DME (as 
confirmed by the central reading center), PDR (as confirmed by the central reading 
center), or ASNV (as confirmed by the investigator) that requires treatment will 
continue participation in the study. The central reading center must confirm progression 
to CI-DME or PDR before the investigator initiates treatment. 
Specific safety, tolerability, and efficacy assessments will occur at every visit as 
presented in the schedule of assessments in Section 3.2. Blood samples for the 
assessment of PK, biomarkers, and pharmacogenomics will be obtained at various time 
points during the study as shown in the schedule of assessments (Section 3.2). 
Participation in the pharmacogenomic and aqueous humor sampling is optional and is 
not required for participation in the study; for those participants electing to participate 
in either of these optional portions, blood samples for the assessment of 
pharmacogenomics and aqueous humor samples will be collected. 
The study will be conducted at approximately 25 sites in the United States. 
Approximately 80 participants are planned for enrollment to provide data for 69 
completed participants (ie, participants who complete the 24-week assessments). The 
overall duration of the study, inclusive of recruitment, is approximately 14 months from 
study initiation (ie, following consent of first participant) to study completion (ie, last 
participant, last visit [LPLV]). The participation period for each participant is 
approximately 32 weeks, inclusive of a 4-week Screening period, 24-week Treatment 
period, and a 4-week Follow-up period. 
A study flow diagram is provided in Figure 1. 
Figure 1 
Study Flow Diagram 
 
3.2 
Schedule of Assessments 
For the complete schedule of assessments, refer to Section 15 (Schedule of Events) and 
Section 
17.4 
(Pharmacokinetic, 
Biomarker, 
Pharmacogenomic, 
and 
Flow 
Cytometry/CBC Sampling) of the clinical study protocol. 
3.3 
Treatment 


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3.3.1 Treatment Administered 
Study treatment consists of AKST4290 or matched placebo. AKST4290 is a film-
coated pink, oblong tablet manufactured by Alkahest, Inc., with a unit strength of 400 
mg and is packaged in “foil-foil” blister packets. Each packet will include 14 tablets. 
Study drug will be self-administered orally b.i.d., approximately 12 hours apart. 
AKST4290 will be administered as a total daily dose of 800 mg (400 mg b.i.d.). 
Matching placebo will be self-administered orally b.i.d. following the same dosing 
instructions as AKST4290. 
Participants will receive training on study drug administration prior to initial study drug 
administration at Visit 2. Study drug will be self-administered in the clinic under the 
supervision of study personnel during every in-clinic visit of the Treatment Period 
(Visits 2-8) after any pre-dose assessments (including PK sample collection), and then 
self-administered at home between study visits. 
When study drug is dispensed, participants will receive a total of 5 packets, which 
represents a 5-week supply (4 weeks of treatment plus an additional week). Study drug 
accountability will be assessed by packet. 
3.3.2 Method of Assigning Subjects to Treatment Groups 
To minimize the potential bias at the time of randomization, the study will be double-
masked and randomized in a 2:1 ratio (active 400 mg b.i.d.: placebo b.i.d.) based on a 
block randomization schema. The randomization will be stratified by DRSS category 
at baseline (moderately severe NPDR [DRSS level 47] to severe NPDR [DRSS level 
53]). The randomization codes will be generated by a statistician who is not involved 
in the study other than generation and maintenance of the randomization codes.  
3.3.3 Masking Procedures 
Maintenance and assignment of the randomization codes will be by a web-based 
randomization system. The study mask for either AKST4290 versus placebo can be 
broken for safety reasons if the information is required for the management of serious 
adverse events (SAEs), severe adverse events (AEs), or pregnancies. Before breaking 
the mask, every attempt should be made to discuss the need with the Sponsor program 
physician, or designee. When some degree of unmasking must occur, this should be 
limited to the fewest number of people on a need-to-know basis. 
The investigator can obtain the AKST4290 or placebo treatment allocation for their 
participant through the web-based randomization system or by contacting the 
interactive response technology vendor. 
3.4 
Efficacy and Safety Variables 


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3.4.1 Efficacy Variables 
3.4.1.1 
Primary Efficacy Variable 
The primary efficacy endpoint is the proportion of participants with a ≥ 3-step 
improvement from baseline on the DRSS score as compared with Week 24.  
Progression of diabetic retinopathy (DR) is measured in discrete steps as described by 
the DRSS (ETDRS 1991b, Staurenghi 2018). The DRSS divides DR into 13 levels 
ranging from the absence of retinopathy to severe retinopathy (see Table 1 of the 
clinical study protocol) and is used to describe overall DR severity as well as the change 
in severity over time.  
After pupillary dilation, the retina of both eyes will be imaged by fundus photography 
(FP) and fluorescein angiography (FA). Both eyes will be investigated by a trained 
technician and evaluated by the investigator. Findings from FP and FA, as provided by 
the central reading center, will be used to determine the DRSS score for each 
participant. Fundus photography will be performed at Visit 1 (Screening), each of the 
in-clinic study visits in the Treatment Period, Visit 2 (Baseline) through Visit 8 (End of 
Treatment [EOT]/Early Termination [ET]), and Visit 9 (End of Study [EOS]); 
fluorescein angiography will be completed at Visits 1 (Screening), Visit 5, and Visit 8 
(EOT/ ET). Fundus photography and FA must be performed once a participant has been 
diagnosed with CI-DME or PDR, and before rescue treatment is given. Given the 
abbreviated scope of the SAP due to the study status, the DRSS level determined for 
each eye will be presented as assigned by the central reading center and a single bilateral 
severity level will not be derived to determine step-wise improvements.  
3.4.1.2 
Secondary Efficacy Variables 
Secondary efficacy endpoints include the following: 
 
• The proportion of participants with a ≥ 2-step improvement from Baseline on 
the DRSS score as compared with Week 24.  
• The proportion of participants progressing to the following vision-threatening 
complications that require treatment: CI-DME, PDR, and/or ASNV as 
assessed by spectral domain optical coherence tomography (SD-OCT), FP, 
and FA, as appropriate. The central reading center must confirm progression 
to CI-DME and PDR before treatment is initiated; progression to ASNV, and 
subsequent treatment, does not require photo documentation.  
• Time to the following vision-threatening event(s) that require treatment: CI-
DME, PDR, and/or ASNV.  
• Effect of AKST4290 on diabetic kidney disease as assessed by changes in 
clinical laboratory values over time (eg, estimated glomerular filtration rate 
[eGFR], urine albumin to creatinine ratio [UACR]).  
• Change from Baseline over time in the WPAI-GH questionnaire.  
The DRSS score as derived from FP and FA findings, is described in Section 3.4.1.1.  


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Assessment of vision-threatening complications including CI-DME, PDR and ASNV 
is based on SD-OCT, FP, and FA as appropriate. Evaluation of FP and FA are described 
in Section 3.4.1.1. The retinal layers of both eyes will be visualized, and thickness 
measured by SD-OCT at Visit 1 (Screening), each in-clinic study visit of the Treatment 
Period, and Visit 9 (EOS). Both eyes will be investigated by a trained technician using 
only specified SD-OCT equipment. A central reading center will be responsible for 
assessing all SD-OCT, OCT-A, FP, VF, and FA images to confirm study eligibility and 
progression to PDR and/or CI-DME and will provide the imaging data for inclusion in 
the database for the evaluation of efficacy and safety. Progression to vision-threatening 
complications is collected directly on the electronic case report form (eCRF) including 
whether or not the complication required treatment. Subjects who progress to a vision-
threatening complication and treatment is indicated by a “Yes” response to the question 
“Was the vision-threatening complication treated?” will be considered to have a vision-
threatening complication that required treatment.  
Collection of laboratory parameters, including eGFR and UACR, is described in 
Section 3.4.2.2.  
The WPAI-GH V2.0 is a 6-question survey used to assess the effects of a participant’s 
health problems (ie, physical or emotional problems or symptoms) on their ability to 
work and perform regular activities during the past seven days. The WPAI-GH will be 
performed at Visit 2 (Baseline), Visit 4, Visit 6, and Visit 8 (EOT/ET). 
The WPAI-GH questions will be analyzed as impairment percentages, in which higher 
percentages indicate greater impairment and less productivity (Reilly 1993). The 
following parameters will be calculated (multiply scores by 100 to express in 
percentages):  
• Percent of work time missed due to health: Q2 divided by (Q2 plus Q4)  
• Percent of impairment while working due to health: Q5 divided by 10  
• Percent of overall work impairment due to health: Q2 divided by (Q2 plus Q4) 
plus [(1 - (Q2 divided by (Q2 plus Q4 ))) multiplied by (Q5 divided by 10)] 
• Percent of activity impairment due to health: Q6 divided by 10 
A subject must have a response provided for all questions used in the percentage for 
the impairment percentage parameter to be calculated.  
3.4.1.3 
Exploratory Efficacy Variables 
Exploratory efficacy endpoints include the following: 
 
• Change from Baseline (gain or loss) over time in BCVA using the ETDRS.  
• Change from Baseline over time in macular volume and CMT as assessed by 
SD-OCT.  
• Proportion of participants with a ≥ 2-step or ≥ 3-step worsening of DRSS 
score from Baseline over time.  


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• BCVA, using the ETDRS, AUC between Baseline and Week 24.  
• PK, pharmacogenomic, and flow cytometry/CBC evaluations of interest.  
• Change in area of ischemia or area of neovascularization (if PDR develops) 
from Baseline over time using OCT-A and/or FA (if available at the site).  
• Change from Baseline over time in VF as evaluated by 
perimetry/microperimetry (if available at the site).  
• Evaluation of the presence of markers of inflammation
 
in aqueous humor collected in a single eye in participants who elect to provide 
these samples.  
Best-corrected visual acuity will be assessed using ETDRS charts at 4 meters initial 
testing distance and assessed in both eyes. The trained technician measuring the BCVA 
using ETDRS should be the same throughout the study period. Assessments of BCVA 
will be performed at Visit 1 (Screening), each in-clinic study visit of the Treatment 
Period, and Visit 9 (EOS). Given the abbreviated scope of the SAP due to the study 
status, AUC intervals will not be calculated.  
Assessments of SD-OCT are described in Section 3.4.1.2. The retinal layers of both 
eyes will be visualized, and thickness measured by SD-OCT and, if available at the site, 
additional scans using OCT-A will be obtained. For sites with the capability to perform 
OCT-A, these assessments should be performed at Visit 2 (Baseline) and Visit 8 
(EOT/ET).  
The DRSS score as derived from FP and FA findings, is described in Section 3.4.1.1. 
Evaluation of VF will be conducted using perimetry and/or microperimetry, per site 
availability. Evaluations of VF takes approximately 10-20 minutes and will be 
performed at Visit 2 (Baseline) and Visit 8 (EOT/ET) for sites with the capability to 
perform the assessment. 
Sampling of biomarker, pharmacogenomic, and flow cytometry/CBC will be 
performed as described Section 17.4 of the clinical study protocol. A PK blood sample 
will be collected and then centrifuged for collection of plasma samples. Biomarker 
plasma aliquots will be obtained from the PK samples. Details on aqueous humor 
collection, plasma biomarkers, blood biomarkers by flow cytometry, and 
pharmacogenomic evaluation are provided in Section 7.1.1.3.8, 7.2.2.2, 7.2.2.3 and 
7.2.2.4 of the clinical study protocol, respectively. 
3.4.2 Safety Variables 
3.4.2.1 
Adverse Events 
An AE is any untoward (unfavorable, harmful, or pathologic) medical occurrence in a 
participant administered a pharmaceutical (investigational) product even if the event 
does not necessarily have a causal relationship with this treatment. 
An AE can, therefore, be any unfavorable and unintended sign (including an abnormal 
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temporally associated with the use of a medicinal (investigational) product whether or 
not related to the medicinal (investigational) product. 
All participants who have given informed consent will be evaluated for AEs. 
3.4.2.2 
Laboratory Parameters 
Blood and urine samples will be collected at each study visit defined in the schedule of 
events (Section 15 of the clinical study protocol). Laboratory tests will include: 
• Hematology: hemoglobin, hematocrit, red blood cell count, white blood cell 
count with differential
, platelets.  
• Chemistry: hemoglobin A1c (HbA1c), glucose, sodium, potassium, calcium, 
inorganic phosphate, chloride, bicarbonate, magnesium, creatinine, aspartate 
aminotransferase 
(AST), 
alanine 
aminotransferase 
(ALT), 
alkaline 
phosphatase, lactate dehydrogenase, direct and indirect bilirubin, blood urea 
nitrogen (BUN), total protein, albumin, and eGFR.  
• Serology: hepatitis B virus (HBV), hepatitis C virus (HCV), and human 
immunodeficiency virus (HIV).  
• Coagulation: partial thromboplastin time (PTT), prothrombin time (PT).  
• Urinalysis: pH, glucose, erythrocytes, leukocytes, protein, nitrites, UACR.  
• Pregnancy: pregnancy testing will be performed at the site in either urine or 
serum; a positive test result must be confirmed by a serum pregnancy test 
performed by the central laboratory.  
Additional laboratory parameters may be reported. Clinical evaluation of liver injury, 
including additional testing, may be performed as defined in Section 17.1 of the clinical 
study protocol. Samples may be used for re-testing, further evaluation of an AE and/or 
assessment, and follow-up of other exploratory endpoints.  
3.4.2.3 
Vital Signs 
Vital sign measurements will include seated systolic and diastolic blood pressure 
(mmHg), heart rate (beats per minute), respiration rate (breaths per minute), and body 
temperature. Vital signs will be measured after the participant has been seated for 5 
minutes. Vital signs will be performed at Screening and every visit in the Treatment 
Period, Visit 2 (Baseline) through 8 (EOT/ET).  
3.4.2.4 
12-lead Electrocardiogram 
Twelve-lead electrocardiograms (ECGs) (I, II, III, aVR, aVL, aVF, V1 - V6) will be 
recorded using a computerized electrocardiograph. A 12-lead ECG will be performed 
after the participant has rested quietly for at least 5 minutes in a supine position at Visit 
1 (Screening), Visit 8 (EOT/ET), and Visit 9 (EOS). In some cases, it may be 
appropriate to repeat abnormal ECGs to rule out technical factors contributing to ECG 
artifacts or abnormality. The final interpretation of the ECGs will be recorded on the 


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appropriate eCRF. The interpretation of the ECGs will be recorded as normal, abnormal 
but not clinically significant, or abnormal and clinically significant. Heart rate, QT and 
QT interval corrected for heart rate using Fridericia’s correction formula (QTcF) will 
also be reported. 
3.4.2.5 
Physical Examination 
At Visit 1 (Screening), a full physical examination will be performed to assess the 
following organ systems: skin, ears, nose, and throat (ENT), head, eyes, lungs/chest, 
heart, abdomen, musculoskeletal, extremities, and lymphatic systems. Height and 
weight will be measured. 
During the study period, a targeted physical examination, including auscultation of the 
heart, measurement of weight, and review of any previous abnormalities identified 
during the full physical examination will be performed. 
3.4.2.6 
Additional Ophthalmological Assessments 
Additional ophthalmological assessments performed include: 
• Slit lamp examination (dilated and undilated) 
• Extended Ophthalmoscopy 
• Intraocular pressure measurements (IOP) 
• Gonioscopy 
The slit lamp examination, IOP measurement, gonioscopy, and extended 
ophthalmoscopy are to be performed in both eyes. The anterior and posterior segments 
of the eye should be assessed. Extended ophthalmoscopy is an assessment of the 
peripheral retina, usually performed with a 20 diopter lens and an indirect 
ophthalmoscope, to examine for retinal abnormalities such as retinal tears, detachment, 
hemorrhage, retinal artery perfusion, etc. Intraocular pressure will be measured using 
applanation Goldmann tonometry in both eyes during each visit. A gonioscope, 
together with a slit lamp or operating microscope, will be used to view the iridocorneal 
angle. Extended ophthalmoscopy is an assessment of the peripheral retina after 
pupillary dilation, usually performed with a 20 diopter lens and an indirect 
ophthalmoscope, to examine for retinal abnormalities such as neovascularization, 
retinal tears, detachment, retinal hemorrhage, etc. Assessments will be performed at 
each study visit defined in the schedule of events (Section 15 of the clinical study 
protocol). 
3.4.3 Pharmacokinetic Variables 
Plasma concentration measurements of AKST4290 and its major metabolites will be 
collected to assess systemic exposure. Sampling of PK will be performed as described 
Section 17.4 of the clinical study protocol.  
3.5 
Data Quality Assurance 


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Report summaries will be generated using validated Base SAS® software, version 9.4 
or higher, on a PC or server-based platform. Additional validated software may be used 
to generate analyses, as needed.  
All SAS programs that create outputs or supporting analysis datasets will be validated 
by a second statistical programmer or biostatistician. At a minimum, validation of 
programs will consist of a review of the program log, review of output or dataset format 
and structure, and independent confirmatory programming to verify output results or 
dataset content. Additionally, all outputs will undergo a review by a senior level team 
member before finalization. 
The content of the source data will be reviewed on an ongoing basis by project statistical 
programmers and statisticians. Data will be checked for missing values, invalid records, 
and extreme outliers through defensive programming applications, analysis-based edit 
checks, and other programmatic testing procedures. All findings will be forwarded to 
the project data manager for appropriate action and resolution. 
4. STATISTICAL METHODS 
4.1 
General Methodology 
Data will be summarized by Emanate biostatistics personnel. Given the paucity of study 
participants, data collected during the study and follow-up period will be reported with 
listings, presented in rich text format, and using recommended ICH numbering. Output 
specifications for all listings will be in conformance with guidelines specified by the 
ICH in Appendix 7 of the Electronic Common Technical Document Specification (Apr 
2003). 
4.1.1 Reporting Conventions 
In general, all data collected and any derived data will be presented in subject data 
listings for all enrolled subjects. Listings will be ordered by site, subject number, 
treatment group, and assessment or event date. The treatment group presented in listings 
will be based upon the actual treatment received. 
4.1.2 Summarization by Visit 
All data, including unscheduled visits, will be included in subject listings. 
4.1.3 Data Handling Rules 
Values reported as greater than or less than some quantifiable limit (eg, “<1.0”) will be 
presented as collected in the subject listings. 
4.1.4 Standard Calculations 
Where appropriate, the calculated study day of each assessment or event will be 
presented with the assessment or event date on subject data listings, where study day 
will be determined as: 


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• The assessment/event date minus the date of first dose of study drug, if the 
assessment/event date is prior to the date of first dose; and 
• The assessment/event date minus the date of first dose of study drug, plus one, 
if the assessment/event date is on or after the date of first dose. 
Other variables requiring calculations will be derived using the following formulas: 
• Days: A duration between two dates expressed in days will be calculated using 
the following conventions: 
o Later date – earlier date + 1, if the earlier date is on or after the date of 
first dose of study drug; or 
o Later date – earlier date, if the earlier date is prior to the date of first 
dose of study drug. 
• Years: A duration expressed in years will be calculated by dividing the duration 
in days by 365.25. 
4.2 
Study Subjects 
4.2.1 Disposition of Subjects 
Subject disposition will be presented in a listing to include the date of first dose, study 
exit date, subject status and reason for early termination (when applicable). Whether or 
not the subject was unmasked including the date/reason when applicable will also be 
reported. A listing of screen failures, to include the date of study exit and reason for 
screen failure, will also be presented.  
4.2.2 Protocol Deviations 
Major and minor protocol violations will be presented in a listing. Major protocol 
violations are protocol deviations captured on-study that are deemed by the Sponsor to 
potentially impact the efficacy or safety conclusions of the study.  
All major protocol violations will be determined and appropriately categorized prior to 
database lock and prior to breaking the mask of the treatment group assignments.  
4.2.3 Plasma Concentrations 
Raw plasma concentration values for AKST4290 and the corresponding metabolites, 
M737 and M227, will be provided in listings by sampling time point for participants 
receiving AKST4290. 
4.2.4 Pharmacokinetic Analysis 
Pharmacokinetic parameters will not be derived due to the limited number of sampling 
timepoints. 
4.3 
Efficacy Evaluations 


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Given the abbreviated scope of the SAP due to the study status, efficacy endpoint 
analysis will be presented in subject data listings, generally relying on the data as 
collected in the electronic data capture (EDC) system or from the central reading center.  
4.3.1 Demographic and Other Baseline Characteristics 
Demographic variables including age, sex, ethnicity, race and childbearing potential 
will be presented in a listing. Baseline disease characteristics include diabetes mellitus 
(DM) type category (Type 1 or Type 2), time since date of DM diagnosis, time since 
DR diagnosis for oculus dexter (OD) and oculus sinister (OS) eyes, and baseline DRSS 
levels for OD and OS eyes. Time since DM or DR diagnosis (in years) is calculated as 
the informed consent date – the date of diagnosis (DM or DR) divided by 365.25.  
Medical history will be presented in a listing. Verbatim terms on case report forms will 
be mapped to preferred terms and system organ classes using the Medical Dictionary 
for Regulatory Activities (MedDRA, version 24.0).  
4.3.2 Measurements of Treatment Compliance 
Compliance to study treatment regimen will be reported as collected on the Study Drug 
Administration and Accountability eCRF page. The number of tablets dispensed and 
returned for each visit will be presented in a listing. A separate listing will be provided 
to present any administration information reported on the Missed/Additional Doses 
eCRF page.  
4.3.3 Efficacy Endpoint Analysis  
The DRSS level determined for each eye, OD and OS, will be presented as reported by 
the central reading center in the fundus photography (Fundus Photography Modified 7 
Field [FP-7M] or Fundus Photography 4 Wide [FP-4W]) assessment; a single bilateral 
severity level will not be derived to determine step-wise improvements/worsening over 
time. Assessments of FA will also be reported in a listing. 
Subjects that progress to any vision-threatening complication that requires treatment 
(CI-DME, PDR, and/or ANSV) will be reported in a listing to include the vision-
threatening complication type, confirmation details associated with the progression, 
and any corresponding treatment information. Additionally, the treatment of PDR 
review criteria collected by the center reading center will also be presented in a listing, 
as applicable.  
Effect of AKST4290 on diabetic kidney disease as assessed by eGFR and UACR will 
be presented in the corresponding laboratory listings as described in Section 4.4.4. 
Responses to WPAI-GH questionnaire, as well as the corresponding derived 
impairment percentages described in Section 3.4.1.2, will be presented in a listing.   
Results for assessments of BCVA using ETDRS, SD-OCT, OCT-A (as available at the 
site), and VF (as available at the site) will be presented in a listing. 
Presentation of pharmacogenomics data will generally be conducted by a separate 
vendor and is outside the scope of this analysis plan. 
 


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 These biomarkers will be measured in plasma samples to investigate any 
change in response to treatment. Blood biomarkers using flow cytometry/CBC will be 
measured to characterize immune cells. Flow cytometry results will be presented in a 
listing. Additional summary and/or presentation of biomarkers data will be conducted 
by a separate vendor and are outside the scope of this analysis plan. 
4.4 
Safety Evaluation 
Safety listings will include all subjects who receive at least one dose of study drug. 
Subjects who do not complete the study, for whatever reason, will have all available 
data up until the time of termination included in the analysis. 
4.4.1 Extent of Exposure 
Extent of exposure to study treatment will provided in listings. The duration of exposure 
will be presented in days and calculated as the date of last dose of study drug minus the 
date of first dose of study drug, plus one. Total dose received (mg) will be calculated 
as the total number of tablets dispensed – total number of tablets returned, multiplied 
by 400.  
4.4.2 Adverse Events 
Treatment-emergent adverse events (TEAEs) are defined as those AEs with onset after 
the first dose of study drug or existing events that worsened after the first dose during 
the study. Events reported with a partial onset date (eg, month and year are reported but 
the day is missing) will be classified as treatment-emergent if it cannot be confirmed 
that the event onset was prior to the first dose of study drug based on the available date 
entries. 
Verbatim terms on case report forms will be mapped to preferred terms and system 
organ classes using the MedDRA, version 24.0.   
Adverse event data will be presented in data listings by subject, treatment group, and 
event. Serious AEs and AEs leading to discontinuation of the study drug will be 
presented in separate data listings. 
4.4.3 Deaths, Other Serious Adverse Events, and Other Significant Adverse Events 
The following AEs will be defined as adverse events of special interest (AESI): 
• 
 
 
 
 
 
 
  


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• 
 
 
  
All deaths during the study, including the post treatment follow-up period, will be listed 
by subject, to include any specifying details of the death. Serious AEs and other 
significant AEs, including those that led to discontinuation or interruption of the study 
drug and AESIs, will be provided in separate subject data listings. 
4.4.4 Clinical Laboratory Evaluation 
All presentation of laboratory results will be based on data analyzed by the central 
laboratory and presented in Système International (SI) units, as suggested by the Center 
for Biologics Evaluation and Research and the Center for Drug Evaluation and 
Research Position on Use of SI Units for Lab Tests (Oct 2013). All data will be included 
in by-subject data listings. Laboratory measurements identified as abnormal (ie, outside 
the normal range) will also be listed separately by subject, laboratory test, and unit. In 
addition, normal ranges provided by the central laboratory will be presented in a 
separate listing. 
4.4.5 Vital Signs, Physical Findings, and Other Observations Related to Safety 
4.4.5.1 
Vital Signs 
Vital sign parameter measurements will be provided in a listing. 
4.4.5.2 
12-Lead Electrocardiogram 
Twelve-Lead ECG interval parameters will be provided in a listing. Twelve-lead ECG 
will be classified by the investigator as “normal,” “abnormal, not clinically significant,” 
or “abnormal, clinically significant.”  
Prolonged QTc intervals will be flagged in the ECG listing as QTcF measurements 
(msec) that are >450 at each visit where ECG is routinely collected per the clinical 
study protocol.  
4.4.5.3 
Physical Examination 
Results of the physical examination will be presented in subject data listings by subject, 
study visit, and body system. 
4.4.5.4 
Slit Lamp Examination (Dilated and Undilated) and Gonioscopy 
Results of slit lamp examination and gonioscopy assessments will be presented in a 
listing.  
4.4.5.5 
Extended Ophthalmoscopy 
Extended ophthalmoscopy assessments of the peripheral retina are categorized as 
absent (or no), present (or yes), or questionable (when available) and will be presented 
in a listing.  


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4.4.5.6 
Intraocular Pressure 
Intraocular pressure (mmHg) will be presented in a listing.  
4.4.5.7 
Prior and Concomitant Medications and Procedures 
Medications will be coded using the World Health Organization Drug Dictionary 
Enhanced (WHODDE), version B3 March 2021. Medications entered on the eCRF will 
be mapped to Anatomical Therapeutic Chemical (ATC) drug class (level 1) and drug 
name.  
The study phase (prior and/or concomitant status) of each medication will be 
determined programmatically based on medication start and end dates. A prior 
medication is defined as any medication administered prior to the date of the first dose 
of study drug. A concomitant medication is defined as any medication administered on 
or after the date of the first dose of study drug. A medication may be defined as both 
prior and concomitant. If it cannot be determined whether a medication was received 
prior to the start of study drug dosing due to partial or missing medication start and/or 
end dates, it will be considered a prior medication. Likewise, if it cannot be determined 
whether a medication was received after the start of study drug dosing, it will be 
considered concomitant. 
The study phase during which each medication was received (eg, prior, concomitant, 
or both) will be presented on the listing of prior and concomitant medications. 
Prior and concomitant procedures will be provided in a listing. The study phase during 
which each procedure was performed (eg, prior or concomitant) will be determined 
based on the reported date of the procedure using the similar logic as described for 
medications; if partial dates are reported for a procedure date, a procedure may be 
defined as both prior and concomitant. If it cannot be determined whether a procedure 
was received prior to the start of study drug dosing due to a partial or missing procedure 
date, it will be considered a prior procedure. Likewise, if it cannot be determined 
whether a procedure was received after the start of study drug dosing, it will be 
considered concomitant. 
4.5 
Determination of Sample Size 
Due to a dearth of studies with a 3-step improvement, as well as potential variabilities 
between each eye, the sample size is powered on the primary hypothesis comparing the 
difference between treatment arms (AKST4290 and placebo) in the proportion of 
participants with a ≥ 2-step improvement of DR severity level on DRSS score in a single 
eye from baseline as compared with Week 24. All calculations were based on the 
following fixed assumptions:  
• Target 80% power.  
• 2-sided alpha = 0.046. 
o It should be noted that to account for Data and Safety Monitoring 
Board (DSMB) interim data reviews, the alpha spending approach has 
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(assuming a total of 4 reviews). The required sample size does not 
change if only three DSMB meetings are necessary.  
• Test of 2 independent proportions based on the normal approximation.  
• Based calculation on PANORAMA (NCT02718326, EYLEA Full Prescribing 
Information), RISE/RIDE (Nguyen 2012, Wykoff 2018), and VIVID/VISTA 
(Korobelnik 2014, Brown 2015) study data.  
The total sample size using the assumptions stipulated is approximately 80 enrolled 
participants to allow for a total of 69 completed participants. The randomization schema 
is 2:1 (AKST4290:placebo). Group sample sizes of 46 in the AKST4290 group and 23 
in the placebo group will achieve approximately 80% power to detect a difference in 
group proportions of 24%. The proportion in the AKST4290 group is assumed to be 
6% under the null hypothesis and 30% under the alternate hypothesis. The proportion 
in the placebo group is assumed to be 6%. 
4.6 
Changes in the Conduct of the Study or Planned Analyses 
This SAP has been modified to accommodate the limited number participants enrolled 
in this prematurely concluded study. Three study participants were randomized and 
taking study drug at the time Investigators were requested to discontinue the study. 
Given the limited data, all data will be presented in the form of listings (as described in 
the Data Listings Layouts document). 
5. REFERENCE LIST 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


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