AN INTERVENTIONAL PHASE 2/3, ADAPTIVE, MULTI-CENTER, RANDOMIZED, DOUBLE-BLIND STUDY TO INVESTIGATE EFFICACY AND SAFETY OF ORAL SISUNATOVIR COMPARED WITH PLACEBO IN NON-HOSPITALIZED SYMPTOMATIC ADULTS WITH RESPIRATORY SYNCYTIAL VIRUS INFECTION WHO ARE AT RISK OF PROGRESSION TO SEVERE ILLNESS
Phase: PHASE2
Conditions: Respiratory Syncytial Virus Infection
Sponsor: Pfizer

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 1
Title Page
AN INTERVENTIONAL PHASE 2/3, ADAPTIVE, MULTI-CENTER, 
RANDOMIZED, DOUBLE-BLIND STUDY TO INVESTIGATE EFFICACY AND 
SAFETY OF ORAL SISUNATOVIR COMPARED WITH PLACEBO IN NON-
HOSPITALIZED SYMPTOMATIC ADULTS WITH RESPIRATORY SYNCYTIAL 
VIRUS INFECTION WHO ARE AT RISK OF PROGRESSION TO SEVERE 
ILLNESS
Study Intervention Number:
PF-07923568
Study Intervention Name:
Sisunatovir
US IND Number:
143479
EU CT Number:
2023-505922-32-01
ClinicalTrials.gov ID:
NCT06079320
Pediatric Investigational Plan Number:
EMEA-002529-PIP02-23
Protocol Number:
C5241007
Phase:
Phase 2/3
Sponsor Legal Address:
Pfizer Inc.
66 Hudson Boulevard East
New York, NY 10001
Brief Title: A Study to Determine if the Study Medicine Called Sisunatovir is Safe and 
Prevents Severe Illness in Adults with Respiratory Syncytial Virus Infection 
This document and accompanying materials contain confidential information belonging to Pfizer. Except 
as otherwise agreed to in writing, by accepting or reviewing these documents, you agree to hold this 
information in confidence and not copy or disclose it to others (except where required by applicable law) 
or use it for unauthorized purposes. In the event of any actual or suspected breach of this obligation, Pfizer 
must be promptly notified.
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 2
Document History
Document 
Version Date
Protocol Amendment 1
30 April 2024
Original protocol
1 September 2023
This amendment incorporates all revisions to date, including amendments made at the 
request of country health authorities and IRBs/ECs and any protocol administrative change 
letter(s).
Protocol Amendment Summary of Changes Table
Amendment 1.0 30 April 2024
Overall Rationale for the Amendment: The main modifications in this Protocol 
Amendment are to expand the primary analysis population in response to external regulatory 
feedback as well as to add a PK interim analysis, add optional PK sampling, and to update 
the ECG requirements based on new safety data.  
Description of Change.
Brief Rationale
Section # and Name
Substantial Modification(s)
The primary estimand was 
expanded to include all 
randomized participants who 
received a dose of study drug, 
regardless of days since symptom 
onset.  The first key secondary 
endpoint was removed 
accordingly.
These changes are incorporated 
into the study objectives, 
endpoints, estimands, overall 
design, analysis set definitions, 
and statistical methods, as 
required.
These updates were made in 
response to external regulatory 
feedback to allow the study 
population to be as inclusive as 
possible of the broader study 
population in regards to symptom 
duration, and to have more 
participants contribute to the 
primary objective.
Protocol Summary
Section 3 Objectives, Endpoints and 
Estimands
Section 4.1 Overall Design
Section 9.1.1.1 Primary Estimand
Section 9.1.1.2 Secondary Estimand
Section 9.1.2 Multiplicity 
Adjustment
Section 9.2 Analysis Sets
Section 9.3.3 Secondary 
Endpoint(s)/Estimand(s) Analysis
Section 9.5 Sample Size 
Determination
The primary analysis 
methodology for the primary 
estimand and several key 
secondary endpoints was 
changed.
This update was made in response 
to external regulatory feedback 
regarding handling of participants 
who discontinue from the study 
early. The updated methodology 
provides for imputation of 
responses for these participants.
Section 9.3.2.2 Main Analytical 
Approach
Section 9.3.3 Secondary 
Endpoint(s)/Estimand(s) Analysis
The required efficacy to continue 
at the futility interim analyses was 
The gamma parameter for the beta 
spending function was increased 
Protocol Summary
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
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Description of Change.
Brief Rationale
Section # and Name
to collect post-dose samples to 
inform population PK modeling.
Clarified restrictions on 
prohibited prior and concomitant 
medications, including the 
creation of new sections on 
Sensitive NTI CYP3A4 
Substrates and Acid Reducing 
Agents.
The updates are to clarify the 
medication restrictions and 
exclude the use of PPI and H2 
blockers based on preliminary 
clinical pharmacology data. 
Section 6.9. Prior and Concomitant 
Therapy
Section 10.9. Appendix 9: Prohibited 
Concomitant Medications That May 
Result in DDI
The minimum total blood 
sampling volume for individual 
participants is reduced from 
80 mL to 70 mL, and 90 mL for 
participants in the optional PK 
sampling collection. An 
additional clarification is made to 
the amount of blood required for 
Specified Protein Research.
Total blood sampling volume 
updated based on changes in PK 
collection schedule.
Section 8.1 Administrative and 
Baseline Procedures
Section 8.7.3 Specified Protein 
Research
Updates were made to the 
sections on biomarkers and 
biological specimens to clarify 
what tests will be performed and 
when.
Additional language was added to 
clarify the allowed specimen 
types and what the specimens will 
be used for.
Table 1 Schedule of Activities
Section 8.1.1 Baseline Procedures
Section 8.7 Biomarkers
Section 8.7.1 Pharmacodynamic 
Biomarkers
Non-substantial Modification(s)
In the SoA, a note is added to the 
rows on retained research 
specimens that these specimens 
are only required at an early 
discontinuation visit if that visit 
occurs on or before Day 15.
This update clarifies when these 
samples should be collected.
Table 1 Schedule of Activities 
The Table on Criteria for ARI 
was moved into the section on 
Clinical Response, and 
clarifications on the definitions of
the Clinical Response were made.
This change helps to clarify the 
criteria to be followed when 
conducting the Clinical Response 
assessment.
Section 8.2.3 Clinical Response
Informed consent for the Optional 
Long-Term Follow up may be 
obtained at any visit up to Day 
28.
Instructions on how to generate a 
token for the additional research 
were modified in the Appendix.
Data transfer does not occur until 
Day 28, and therefore it is 
acceptable to consent or decline to 
participate in the Long-Term 
Follow up at any time up until 
then.
The update to the site instructions 
in Appendix 10 will help to 
clarify the process.
Table 1 Schedule of Activities
Section 10.10.1 United States
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
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TABLE OF CONTENTS
LIST OF TABLES...................................................................................................................14
1. PROTOCOL SUMMARY...................................................................................................15
1.1. Synopsis ..................................................................................................................15
1.2. Schema ....................................................................................................................24
1.3. Schedule of Activities .............................................................................................25
2. INTRODUCTION ...............................................................................................................33
2.1. Study Rationale .......................................................................................................33
2.2. Background .............................................................................................................33
2.2.1. Nonclinical Pharmacology..........................................................................34
2.2.2. Nonclinical Pharmacokinetics and Metabolism .........................................34
2.2.3. Nonclinical safety.......................................................................................34
2.2.4. Clinical Overview.......................................................................................35
2.3. Benefit/Risk Assessment.........................................................................................38
2.4. Risk Assessment......................................................................................................39
2.4.1. Benefit Assessment.....................................................................................40
2.4.2. Overall Benefit/Risk Conclusion................................................................40
3. OBJECTIVES, ENDPOINTS, AND ESTIMANDS ...........................................................40
4. STUDY DESIGN.................................................................................................................43
4.1. Overall Design.........................................................................................................43
4.2. Scientific Rationale for Study Design.....................................................................44
4.2.1. Rationale for end point selection................................................................44
4.2.2. Rationale for Study Population...................................................................44
4.2.3. Diversity of Study Population ....................................................................45
4.2.4. Rationale for Comparator ...........................................................................45
4.2.5. Rationale for Adaptive or Novel Study Design..........................................45
4.2.6. Choice of Contraception/Barrier Requirements .........................................45
4.3. Justification for Dose ..............................................................................................45
4.4. End of Study Definition ..........................................................................................46
5. STUDY POPULATION......................................................................................................46
5.1. Inclusion Criteria.....................................................................................................46
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
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5.2. Exclusion Criteria....................................................................................................47
5.3. Lifestyle Considerations..........................................................................................49
5.3.1. Contraception..............................................................................................49
5.4. Pre-screening consent and pre-screening viral testing (optional, if applicable) .....49
5.5. Screen Failures ........................................................................................................50
6. STUDY INTERVENTION(S) AND CONCOMITANT THERAPY.................................50
6.1. Study Intervention(s) Administered........................................................................51
6.1.1. Administration............................................................................................51
6.1.2. Medical Devices .........................................................................................52
6.2. Preparation, Handling, Storage, and Accountability...............................................52
6.2.1. Preparation and Dispensing........................................................................53
6.3. Assignment to Study Intervention...........................................................................53
6.4. Blinding...................................................................................................................53
6.4.1. Blinding of Participants..............................................................................54
6.4.2. Blinding of Site Personnel..........................................................................54
6.4.3. Blinding of the Sponsor..............................................................................54
6.4.4. Breaking the Blind......................................................................................54
6.5. Study Intervention Compliance...............................................................................55
6.6. Dose Modification...................................................................................................55
6.7. Continued Access to Study Intervention After the End of the Study......................55
6.8. Treatment of Overdose............................................................................................55
6.9. Prior and Concomitant Therapy ..............................................................................56
7. DISCONTINUATION OF STUDY INTERVENTION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL...........................................................................58
7.1. Discontinuation of Study Intervention ....................................................................58
7.1.1. Potential Cases of Acute Kidney Injury .....................................................58
7.1.2. Liver Injury.................................................................................................60
7.1.3. ECG Changes..............................................................................................60
7.1.4. Pregnancy ...................................................................................................61
7.1.5. COVID-19 (SARS-CoV-2) and influenza..................................................61
7.1.6. Temporary Discontinuation........................................................................61
7.1.7. Rechallenge.................................................................................................61
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
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7.2. Participant Discontinuation/Withdrawal From the Study.......................................61
7.2.1. Withdrawal of Consent...............................................................................62
7.3. Lost to Follow-Up ...................................................................................................62
8. STUDY ASSESSMENTS AND PROCEDURES...............................................................62
8.1. Administrative and Baseline Procedures.................................................................62
8.1.1. Baseline Procedures....................................................................................63
8.1.2. Telehealth Visits.........................................................................................64
8.2. Efficacy Assessments..............................................................................................64
8.2.1. RSV-related hospitalizations and Medical Details.....................................64
8.2.2. Survival status.............................................................................................65
8.2.3. Clinical response.........................................................................................65
8.2.4. RSV-related lower respiratory tract infection.............................................66
8.2.5. Post-treatment ARI.....................................................................................68
8.2.6. Oxygen Support Details..............................................................................68
8.2.7. Imaging Assessments..................................................................................68
8.2.8. PRO Assessment.........................................................................................68
8.2.8.1. EQ-5D-5L..................................................................................68
8.2.9. Household Characteristics ..........................................................................69
8.3. Safety Assessments .................................................................................................69
8.3.1. Physical Examinations................................................................................69
8.3.2. Vital Signs ..................................................................................................70
8.3.2.1. Blood Pressure and Pulse Rate..................................................70
8.3.2.2. Temperature and Respiratory Rate............................................70
8.3.2.3. Oxygen Saturation.....................................................................70
8.3.3. Electrocardiograms.....................................................................................70
8.3.3.1. Alternative Facilities for Electrocardiograms ...........................71
8.3.4. Clinical Safety Laboratory Assessments ....................................................71
8.3.4.1. Alternative Facilities for Clinical Safety Laboratory 
Assessment ........................................................................................72
8.3.5. Pregnancy Testing ......................................................................................72
8.4. Adverse Events, Serious Adverse Events, and Other Safety Reporting .................72
8.4.1. Time Period and Frequency for Collecting AE and SAE Information.......73
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
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8.4.1.1. Reporting SAEs to Pfizer Safety...............................................73
8.4.1.2. Recording Nonserious AEs and SAEs on the CRF...................73
8.4.2. Method of Detecting AEs and SAEs ..........................................................74
8.4.3. Follow-Up of AEs and SAEs......................................................................74
8.4.4. Regulatory Reporting Requirements for SAEs...........................................74
8.4.5. Environmental Exposure, Exposure During Pregnancy or 
Breastfeeding, and Occupational Exposure.....................................................75
8.4.5.1. Exposure During Pregnancy......................................................75
8.4.5.2. Exposure During Breastfeeding ................................................76
8.4.5.3. Occupational Exposure .............................................................77
8.4.6. Cardiovascular and Death Events...............................................................77
8.4.7. Disease-Related Events and/or Disease-Related Outcomes Not 
Qualifying as AEs or SAEs..............................................................................77
8.4.8. Adverse Events of Special Interest.............................................................77
8.4.8.1. Lack of Efficacy........................................................................77
8.4.9. Medical Device Deficiencies......................................................................77
8.4.10. Medication Errors.....................................................................................78
8.5. Pharmacokinetics ....................................................................................................79
8.6. Genetics...................................................................................................................80
8.6.1. Specified Genetics ......................................................................................80
8.6.2. Retained Research Samples for Genetics ...................................................80
8.7. Biomarkers ..............................................................................................................80
8.7.1. Pharmacodynamic Biomarkers...................................................................81
8.7.2. Specified Gene Expression (RNA) Research .............................................81
8.7.3. Specified Protein Research.........................................................................81
8.7.4. Specified Metabolomic Research ...............................................................81
8.7.5. Retained Research Samples for Biomarkers...............................................81
8.8. Immunogenicity Assessments.................................................................................82
8.9. Health Economics ...................................................................................................82
9. STATISTICAL CONSIDERATIONS ................................................................................82
9.1. Statistical Hypotheses .............................................................................................82
9.1.1. Estimands....................................................................................................82
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
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9.1.1.1. Primary Estimand......................................................................82
9.1.1.2. Secondary Estimands ................................................................83
9.1.2. Multiplicity Adjustment..............................................................................85
9.2. Analysis Sets ...........................................................................................................86
9.3. Statistical Analyses .................................................................................................87
9.3.1. General Considerations...............................................................................87
9.3.2. Primary Endpoint/Estimand Analysis.........................................................88
9.3.2.1. Definition of Endpoint ..............................................................88
9.3.2.2. Main Analytical Approach........................................................88
9.3.2.3. Sensitivity Analyses ..................................................................88
9.3.2.4. Supplementary Analyses...........................................................88
9.3.3. Secondary Endpoints/Estimands Analysis .................................................89
9.3.3.1. Pharmacokinetics ......................................................................90
9.3.4. Tertiary/Exploratory Endpoint(s) Analysis ................................................90
9.3.5. Safety Analyses ..........................................................................................91
9.3.6. Other Analyses............................................................................................91
9.4. Interim Analyses .....................................................................................................91
9.5. Sample Size Determination.....................................................................................93
10. SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS..........................................................................................................94
10.1. Appendix 1: Regulatory, Ethical, and Study Oversight Considerations...............94
10.1.1. Regulatory and Ethical Considerations ....................................................94
10.1.1.1. Reporting of Safety Issues and Serious Breaches of the 
Protocol or ICH GCP.........................................................................95
10.1.2. Financial Disclosure .................................................................................95
10.1.3. Informed Consent Process........................................................................95
10.1.3.1. Electronic Consent ..................................................................96
10.1.4. Data Protection .........................................................................................96
10.1.5. Committees Structure ...............................................................................97
10.1.5.1. Data Monitoring Committee ...................................................97
10.1.6. Dissemination of Clinical Study Data ......................................................97
10.1.7. Data Quality Assurance ............................................................................98
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
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10.1.8. Source Documents....................................................................................99
10.1.9. Use of Medical Records..........................................................................100
10.1.10. Study and Site Start and Closure ..........................................................101
10.1.11. Publication Policy.................................................................................101
10.1.12. Sponsor’s Medically Qualified Individual............................................102
10.2. Appendix 2: Clinical Laboratory Tests ...............................................................103
10.3. Appendix 3: Adverse Events: Definitions and Procedures for Recording, 
Evaluating, Follow-Up, and Reporting ...................................................................105
10.3.1. Definition of AE .....................................................................................105
10.3.2. Definition of an SAE ..............................................................................106
10.3.3. Recording/Reporting and Follow-Up of AEs and/or SAEs During 
the Active Collection Period..........................................................................107
10.3.4. Reporting of SAEs..................................................................................111
10.4. Appendix 4: Contraceptive and Barrier Guidance ..............................................113
10.4.1. Male Participant Reproductive Inclusion Criteria..................................113
10.4.2. Female Participant Reproductive Inclusion Criteria...............................113
10.4.3. Woman of Childbearing Potential ..........................................................113
10.4.4. Contraception Methods...........................................................................114
10.5. Appendix 5: Genetics..........................................................................................116
10.6. Appendix 6: Liver Safety: Suggested Actions and Follow-Up Assessments .....117
10.7. Appendix 7: Kidney Safety Monitoring Guidelines ...........................................119
10.7.1. Laboratory Assessment of Change in Kidney Function and 
Detection of Kidney Injury............................................................................119
10.7.2. Age-Specific Kidney Function Calculation Recommendations.............119
10.7.2.1. Adults (18 Years and Above)—2021 CKD-EPI 
Equations [30] .................................................................................119
10.7.3. Kidney Function Calculation Tools........................................................120
10.7.4. Adverse Event Grading for Kidney Safety Laboratory 
Abnormalities.................................................................................................120
10.8. Appendix 8: ECG Findings of Potential Clinical Concern .................................121
10.9. Appendix 9: Prohibited Concomitant Medications That May Result in DDI.....123
10.10. Appendix 10: Country-Specific Requirements .................................................127
10.10.1. United States.........................................................................................127
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
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10.10.1.1. Management and reporting of adverse events/adverse 
reactions for additional research using real world data...................127
10.10.2. China.....................................................................................................127
10.10.3. United Kingdom ...................................................................................128
10.11. Appendix 11: Abbreviations .............................................................................129
11. REFERENCES ................................................................................................................134
LIST OF TABLES
Table 1.
Study Schedule of Activities ....................................................................25
Table 2.
Criteria for ARI.........................................................................................65
Table 3.
Criteria for LRTI......................................................................................66
Table 4.
Criteria for severe LRTI ...........................................................................67
Table 5.
Intensity grading for LRTI........................................................................68
Table 6.
Protocol-Required Laboratory Assessments...........................................103
Table 7.
Protocol-Required Laboratory Assessments – Reflex Testing...............104
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
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1. PROTOCOL SUMMARY 
1.1. Synopsis
Protocol Title: 
An Interventional Phase 2/3, Adaptive, Multi-Center, Randomized, Double-Blind Study To 
Investigate Efficacy And Safety Of Oral Sisunatovir Compared With Placebo In Non-
Hospitalized Symptomatic Adults With Respiratory Syncytial Virus Infection Who Are At 
Risk Of Progression To Severe Illness
Brief Title: 
A Study to Determine if the Study Medicine Called Sisunatovir is Safe and Prevents Severe 
Illness in Adults with Respiratory Syncytial Virus Infection 
Regulatory Agency Identification Number(s):
US IND Number:
143479
EU CT Number:
2023-505922-32-01
ClinicalTrials.gov ID:
NCT06079320
Pediatric Investigational Plan Number:
EMEA-002529-PIP02-23
Protocol Number:
C5241007
Phase:
Phase 2/3
Rationale:
Older adults and individuals affected by cardiopulmonary comorbidities or compromised 
immune system are at increased risk of poor clinical outcomes following respiratory 
syncytial virus (RSV) infection. Currently, no oral treatment is approved for this indication. 
The purpose of this trial is to investigate the safety and efficacy of orally administered 
sisunatovir, a potent inhibitor of the RSV F protein that prevents entry into the host cells, for 
the treatment of RSV infection in non-hospitalized adults at risk of severe illness. 
Objectives, Endpoints, and Estimands:
All objectives, endpoints, and estimands will be evaluated in non-hospitalized adults who are 
infected with RSV and are at high risk of severe illness. The treatment effect is evaluated in 
the population of study participants who are randomized and treated irrespective of their 
compliance to the planned course of treatment or use of concomitant medications. The 
primary analysis and key secondary analyses are conducted in adults with confirmed RSV 
infection. 
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
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Objectives
Endpoints
Estimands
Primary:
! To compare the 
efficacy of sisunatovir 
to placebo for 
treatment of RSV 
among non-
hospitalized adults at 
high risk for severe 
illness.
! Proportion of participants with 
RSV-related hospitalization or death 
from any cause through Day 28.
! The difference in treatment proportions of 
patients experiencing RSV-related 
hospitalization or death from any cause through 
Day 28.
Key Secondary:
!
To compare the 
efficacy of 
sisunatovir to 
placebo for 
treatment of RSV
among non-
hospitalized adults at 
high risk for severe 
illness.
! Proportion of participants with 
RSV-related visits (urgent 
care/emergency department 
[ED]/hospital) or death from any 
cause through Day 28.
! The difference in treatment proportions of 
patients experiencing RSV-related visits (urgent 
care/ED/hospital) or death from any cause 
through Day 28. A hospital visit of any duration 
will be included. 
! Proportion of participants with 
progression of lower respiratory 
tract infection (LRTI) through 
Day 10.
! The difference in treatment proportions of 
patients with progression of LRTI through Day 
10 will be evaluated in the population of 
participants who do not have RSV-related 
severe LRTI (sLRTI-RSV) at randomization. 
! Proportion of participants with
development of LRTI through 
Day 10.
! The difference in treatment proportions of 
patients who develop sLRTI-RSV or
RSV-related non-severe LRTI (nsLRTI-RSV)
through Day 10 will be evaluated in the 
population of participants who do not have 
sLRTI-RSV or nsLRTI-RSV at randomization.
! Proportion of participants with 
resolution of LRTI at Day 15.
! The difference in treatment proportions of 
patients with resolution of LRTI at Day 15 will 
be evaluated in the population of participants 
who have sLRTI-RSV nsLRTI-RSV at 
randomization.
! Mean number of days alive and free 
from hospital stay (hospital-free 
days) through Day 28.
! The difference in treatment means of number of 
days alive and free from hospital stay (hospital-
free days) through Day 28.
Other Secondary:
! To compare the 
efficacy of sisunatovir 
to placebo for 
treatment of RSV
among non-
hospitalized adults at 
high risk for severe 
illness.
! Proportion of participants with 
progression of LRTI through Day 3, 
5, 15, and 28.
! The difference in treatment proportions of 
patients with progression of LRTI through Day 
3, 5, 15, and 28 will be evaluated in the 
population of participants who do not have 
sLRTI-RSV at randomization.
! Proportion of participants with 
development of LRTI through 
Day 3, 5, 15, and 28.
! The difference in treatment proportions of 
patients who develop sLRTI-RSV or nsLRTI-
RSV through Day 3, 5, 15, and 28 will be 
evaluated in the population of participants who 
do not have sLRTI-RSV or nsLRTI-RSV at 
randomization.
! Proportion of participants with
resolution of LRTI at Day 3, 5, 10, 
and 28.
! The difference in treatment proportions of 
patients with resolution of LRTI at Day 3, 5, 
10, and 28 will be evaluated in the population 
of participants who have sLRTI-RSV or 
nsLRTI-RSV at randomization. 
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Objectives
Endpoints
Estimands
! Proportion of participants with 
improvement in LRTI status at 
Day 3, 5, 10, 15, and 28.
! The difference in treatment proportions of 
patients with improvement in LRTI status at 
Day 3, 5, 10, 15, and 28 will be evaluated in the 
population of participants who have sLRTI-
RSV or nsLRTI-RSV at randomization.
! Number of RSV related days in 
hospital through Day 28.
! Number of RSV related days in the 
intensive care unit (ICU) through 
Day 28.
! The difference in treatment means of number of 
RSV related days in hospital and separately, 
number of RSV related days in ICU, through 
Day 28.
! Proportion of participants with a 
clinical response of Improvement or 
Resolution at Day 5, 10, 15, and 28.
! The difference in treatment proportions of 
patients with Improvement or Resolution at 
Day 5, 10, 15, and 28.
! To compare 
nasopharyngeal (NP) 
viral load changes 
among non-
hospitalized adults at 
high risk for severe 
illness treated with 
sisunatovir relative to 
placebo.
! Proportion of participants with 
undetectable RSV viral load at each 
study visit through Day 28.
! Change from baseline in RSV viral 
load at each study visit through Day 
28.
! The difference in treatment proportions of 
patients with undetectable RSV viral load at 
each visit through Day 28
! The difference in treatment means of change 
from baseline in RSV viral load at each study 
visit through Day 28.
! To describe the safety 
and tolerability of 
sisunatovir relative to 
placebo among non-
hospitalized adults at 
high risk for severe 
illness.
! Proportion of participants with 
treatment emergent adverse events 
(TEAEs) through Day 35
! Proportion of participants with 
SAEs through Day 35.
! NA.
! To determine the 
pharmacokinetic (PK) 
of sisunatovir among 
non-hospitalized 
adults at high risk for 
severe illness.
! Plasma concentrations of 
sisunatovir at steady state (Day 3 or 
later).
! NA.
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 20
4. Has at least 1 of the following characteristics or underlying medical conditions:
!
65 years of age or older.
!
Chronic lung disease that is symptomatic or requiring treatment, including but not 
limited to: chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis 
(CF), pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), alpha-1 anti-
trypsin deficiency, or pulmonary sarcoidosis. 
!
Heart failure (functional class II-IV according to New York Heart Association 
[NYHA] classification).
!
Immunosuppressive disease or condition (eg, hematological malignancy, chimeric 
antigen receptor T-cell [CAR-T], bone marrow or organ transplant recipient, primary 
immune deficiency, or human immunodeficiency virus [HIV] infection with cluster 
of differentiation (CD) 4+ cell count <200 / μL within the last 6 months) OR use of at 
least 1 of the following immune-weakening medications: 
o
Recent treatment with corticosteroids equivalent to prednisone ≥20 mg daily for 
at least 14 consecutive days, all of which must have been within the last 30 days 
prior to study entry OR are currently receiving ≥20 mg daily that must have been 
administered for at least 14 consecutive days at the time of study entry.
o
Active treatment causing significant immunosuppression, including alkylating 
agents, antimetabolites, transplant-related immunosuppressive drugs, cancer 
chemotherapeutic agents, tumor necrosis factor (TNF) blockers, or other highly 
immunosuppressive drugs such as biologics (eg, ustekinumab, anti-CD20).
Exclusion Criteria 
Participants with any of the following characteristics/conditions will be excluded:
1. Any medical condition (eg, confirmed concurrent active systemic infection other than 
RSV including bacterial, fungal, or viral) or psychiatric condition including recent 
(within the past year) or active suicidal ideation/behavior or laboratory abnormality that 
may increase the risk of study participation or, in the investigator’s judgment, make the 
participant inappropriate for the study or interfere with the evaluation of response to the 
study intervention.
2. Diagnosis of viral respiratory infections other than RSV including influenza and severe 
acute respiratory syndrome coronavirus 2 (SARS-CoV-2), within 7 days of 
randomization. A negative test for SARS-CoV-2 and influenza is required within 7 days 
of randomization.
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 2 1
3.
C urre nt nee d f or h os pitalizati o n or a ntici pate d nee d f or h os pitalizati o n f or a n y reas o n t o 
pr o vi de i n patie nt/ac ute care wit hi n 2 4 h o urs after ra n d o mizati o n i n t he cli nical o pi ni o n of 
t he site i n vesti gat or.
4.
A n y  cli nicall y si g nifica nt E C G a b n or malit y i n t he pre- d ose E C G t hat, per i n vesti gat or 
j u d ge me nt, ma y affect partici pa nt safet y.
5.
C urre nt or rece nt use of a n y  pr o hi bite d c o nc o mita nt me dicati o n t hat ma y res ult i n a 
cli nicall y si g nifica nt dr u g-dr u g i nteracti o n.
6.
Use of oral or i n hale d ri ba viri n i n pri or 3 0 da y s or a ntici pate d use d uri n g t he st u d y. 
7.
Pri or a d mi nistrati o n of st u d y  dr u g in a sis u nat o vir trial, rece nt a d mi nistrati o n of a n 
i n vesti gati o nal dr u g or vacci ne ( wit hi n 3 0 da ys or 5 half-li ves), or c o nc urre nt 
partici pati o n i n a st u d y  of a n ot her i n vesti gati o nal dr u g or vacci ne.
8.
Re nal i m pair me nt defi ne d b y  a n esti mate d gl o mer ular filt rati o n rate (e G F R) < 3 0 
m L / mi n/ 1. 7 3 m2 or recei vi n g dial ys is.
9.
Acti ve li ver disease wit h as partate a mi n otra nsferase ( A S T) or ala ni ne a mi n otra nsferase
( A L T) > 3 u p per li mit of n or mal ( U L N), or T otal bilir u bi n ≥2 × U L N ( F or Gil bert’s 
s yn dr o me, direct bilir u bi n > U L N is e xcl usi o nar y ) wit hi n t he past 3 m o nt hs, or li ver 
f u ncti o n i m pair me nt wit h Class B or C per C hil d P u g h classificati o n.
1 0. Has h y perse nsiti vit y  t o or ot her c o ntrai n dicati o n t o a n y of t he c o m p o ne nts of t he st u d y 
i nter ve nti o ns, as deter mi ne d b y t he i n vesti gat or.
1 1. I n vesti gat or site staff directl y i n v ol ve d i n t he c o n d uct of t he st u d y a n d t heir fa mil y 
me m bers, site staff ot her wise s u per vise d b y t he i n vesti gat or, a n d s p o ns or a n d s p o ns or 
dele gate e m pl o y ees directl y i n v ol ve d i n t he c o n d uct of t he st u d y a n d t heir fa mil y 
me m bers.
St u d y Ar ms a n d D ur ati o n:
T otal d urati o n of st u d y  partici pati o n f or eac h partici pa nt is a p pr o xi mati vel y 5 wee ks ( Da y 3 5 
± 2 da y s) di vi de d as f oll o ws: 

Scree ni n g a n d Ra n d o mizati o n pr oce d ures ca n be o n t he sa me da y  or o ver t w o 
c o nsec uti ve da ys. T he partici pa nt m ust be ra n d o mize d b y t he sec o n d da y ( Da y 1 of 
st u d y i nter ve nti o n).

A 5 -d a y  d osi n g peri o d; If t he first d ose of st u dy i nter ve nti o n is a d mi nistere d at a ti me 
t hat w o ul d o nl y all o w o ne d ose t o be ta ke n o n Da y 1, t he d osi n g peri o d will c o ntin ue 
u ntil Da y  6 t o all o w f or a t otal of 
d oses.

A 4 -wee k f oll o w -u p peri o d after t he last st u d y  i nter ve nti o n d ose. 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 2 2
St u d y I nter ve nti o n(s)
I nter ve nti o n N a me
Sis u nat o vir  
m g
Place b o
Use
E x peri me ntal
Place b o
I M P or NI M P/ A x M P
I n vesti gati o nal me dici nal pr o d uct (I M P)
I M P
D ose F or m ul ati o n
ta blet
ta blet
U nit D ose Stre n gt h(s)
1 0 0 m g 
0 m g
R o ute of A d mi nistr ati o n
Oral
Oral
St u d y Ar m(s)
Ar m Title
Sis u nat o vir
Place b o
Ar m Descri pti o n
Partici pa nts will recei ve ta blets of 1 0 0 
m g of sis u nat o vir 
fr o m Da y 1 t o 
Da y 5 ( 
d oses).
Partici pa nts will recei ve  
matc hi n g place b o 
ta blets 
fr o m Da y 1 t o Da y 5 ( 
d oses).
St atistic al Met h o ds:
T he pri mar y  esti ma n d is t he differe nce i n treat me nt pr o p orti o ns of partici pa nts e x perie nci n g 
R S V -relate d h os pitalizati o n or deat h fr o m a ny ca use t hr o u g h Da y 2 8 i n n o n -h os pitalize d 
a d ults wit h R S V i nfecti o n w h o are at i ncrease d ris k of pr o gressi o n t o se vere ill ness. T his will 
be esti mate d irres pecti ve of c o m plia nce t o t he pla n ne d c o urse of treat me nt or use of 
c o nc o mita nt me dicati o ns.
T he pri mar y  a nalys is will als o be c o n d ucte d f or t he t w o pla n ne d efficac y I As. T w o-si de d 
9 5 % CI  (a dj uste d f or t he pla n ne d I As) a n d ass ociate d p- val ue f or t he n ull h yp ot hesis of n o 
differe nce bet wee n treat me nt gr o u ps will be prese nte d. Si g nific a nce le vel f or t he pri mar y  
assess me nt of efficac y will be deter mi ne d usi n g t he
h at t he sec o n d 
efficac y IA a n d t he fi nal a nal ys is. Si g nifica nce le vel f or assess me nt of f utilit y will be 
deter mi ne d usi n g t h
 
 a p pr oac h at t he first a n d sec o n d efficac y IAs. T he o verall si g nifica nce le vel is 
set at 2. 5 % ( 1 si de d).
T his st u d y  is desi g ne d t o ha ve 9 0 % statistical p o wer t o s h o w a differe nce bet wee n t he 
treat me nt ar ms (sis u nat o vir vers us place b o) of  
% i n t he pr o p orti o n of partici pa nts 
h os pitalize d/ d y i n g, usi n g a 1-si de d T ype I err or rate of 2. 5 %. T he pr o p orti o n of 
h os pitalizati o n/ deat h i n t he place b o ar m is ass u me d t o be
%. A  
% a bs ol ute differe nce 
re prese nts a 
% relati ve re d ucti o n fr o m place b o.
F or a 2 -sa m ple pr o p orti o n test, t he sa m ple size nee de d t o detect t his differe nce wit h 9 0 % 
p o wer at a 1 -si de d si g nifica nce le vel of 2. 5 % was deter mi ne d t o be 
 ra n d o mize d 
partici pa nts. Ass u mi n g a 
, t he re q uire d t otal sa m ple size f or t he pri mar y  
a nal ys is will be i ncrease d t o a p pr o xi matel y  
partici pa nts. Ass u mi n g 
 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 33
2. INTRODUCTION
Sisunatovir (PF-07923568, formerly RV521) is a potent inhibitor of RSV F protein mediated 
fusion that is currently being investigated as a treatment of adults with naturally acquired 
RSV infection who are at increased risk of developing severe illness. Additional studies are 
being conducted to evaluate sisunatovir as a treatment of RSV infection in pediatric patients.
2.1. Study Rationale 
Currently there are no approved oral treatments for RSV, and patients that progress to severe 
illness are hospitalized and offered supportive care only [1]. The purpose of the study is to 
evaluate the efficacy and safety of sisunatovir in preventing severe clinical outcomes, 
including development of LRTI, hospitalization and death, in an adult population of naturally 
infected RSV participants with risk factors for severe illness, defined here as older age, 
chronic lung disease, heart failure, or a compromised immune system. The study will also 
evaluate the impact of sisunatovir on changes in RSV viral load that is obtained from 
nasopharyngeal samples.
2.2. Background 
RSV belongs to the recently defined Pneumoviridae family, Orthopneumovirus genus
[2,3]and was discovered more than 60 years ago [4] RSV has since been recognized as one of 
the most common causes of acute respiratory tract infections in adults. RSV is a major cause 
of morbidity and mortality among children [5], elderly people, people with cardiopulmonary 
comorbidities (such as COPD, asthma, or congestive heart failure), and individuals with a 
compromised immune system [6,7].An estimated 1.5 (95% CI 0.3 to 6.9) million episodes of 
RSV-related acute respiratory illness occurred in older adults in industrialized countries 
worldwide in 2015, and of these episodes approximately 14.5% involved a hospital 
admission. Globally, an estimated 14,000 in-hospital deaths in 2015 were associated with 
RSV-related acute respiratory illness [8]. Adults infected with RSV can have variable clinical 
findings that range in severity from mild respiratory symptoms to severe LRTI. Host 
immunity to RSV diminishes over time and can lead to recurrent infections [9].
At present, two adult RSV vaccines have regulatory approval in some countries to prevent 
progression to severe illness. However, no specific treatment with antivirals is available for 
patients who acquire the infection, other than aerosolized ribavirin [1]. Ribavirin, a 
nucleoside analogue, is the only licensed antiviral for the treatment of RSV in pediatric 
patients , but clinical use is restricted due to its limited antiviral potency, delivery route, 
toxicity, and teratogenic potential [10,11]. There is, thus, an unmet need for more targeted 
and better tolerated antivirals.
Sisunatovir (PF-07923568) is a novel, oral, potent inhibitor of RSV F protein mediated 
fusion and exerts antiviral activity against RSV by inhibiting viral entry into host cells. In 
this way, F protein inhibition may reduce both viral replication and pathology, reducing the 
severity of RSV related clinical outcomes. Thus, sisunatovir may provide clinical benefit to 
adult participants with RSV disease. 
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 3 4
T he sis u nat o vir precli nical pr ofile, as well as t he efficac y , safet y a n d t olera bilit y data fr o m 
t he i nitial h u ma n st u dies t hat are s u m marize d i n t his pr ot oc ol, pr o vi de a str o n g rati o nale f or 
t he cli nical de vel o p me nt of sis u nat o vir.
2. 2. 1. N o ncli nic al P h ar m ac ol o g y
See t he c urre nt I B f or f urt her details.
2. 2. 2. N o ncli nic al P h ar m ac o ki netics a n d Met a b olis m
I n a ni mal p har mac o ki netic st u dies sis u nat o vir s h o we d pr ol o n ge d Tma x , m o derate-hi g h C L, 
hi g h v ol u me of distri b uti o n, a n d oral bi oa vaila bilit y  of 4 6 %, 4 2- 1 3 2 %, a n d 6 3 % i n m o use, 
rat, a n d d o g, res pecti vely. 
Plas ma pr otei n bi n di n g of sis u nat o vir was l o w t o m o derate acr oss s pecies, wit h a vera ge 
fracti o n u n b o u n d of 
 i n h u ma n, m o use, rat, d o g a n d 
g ui nea pi g, res pecti vel y. Sis u nat o vir s h o we d e xte nsi ve distri b uti o n t o t he l u n g i n st u dies of 
rats.
Sis u nat o vir is a s u bstrate of
 a n d is meta b olize d pri maril y b y
.
Sis u nat o vir was e val uate d f or p ote ntial i n hi biti o n of C Y Ps a n d tra ns p orters i n vitr o. O verall, 
t he pri mar y D DI ris ks f or sis u nat o vir are
 a n d p ote ntial ris k f or 
.
See t he c urre nt I B f or f urt her details.
2. 2. 3. N o ncli nic al s afet y
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 3 5
See t he c urre nt I B f or f urt her details.
2. 2. 4. Cli nic al O ver vie w
T o date, 9 cli nical st u dies of sis u nat o vir ha ve bee n c o m plete d; a t otal of 2 6 4 healt h y  a d ult 
partici pa nts a n d 4 1 pe diatric patie nts wit h R S V -L R TI  recei ve d sis u nat o vir i n t hese st u dies. 
K e y  desi g n feat ures of t he c o m plete d cli nical st u dies are pr o vi de d i n t he I B a n d s u m maries 
of t he ke y cli nical p har mac ol o g y , cli nical efficac y a n d clinical safet y data fr o m t he 
c o m plete d st u dies are pr o vi de d i n t he secti o ns bel o w. 
C 5 2 4 1 0 0 2 is a n R S V c halle n ge st u d y w here 6 6 healt h y  a d ult male a n d fe male v ol u nteers 
were i n oc ulate d wit h c halle n ge vir us. After t he first p ositi ve P C R test fr o m a nasal was h or 
after 5 da ys ( w hic he ver occ urre d first), partici pa nts were ra n d o mize d 2: 1 t o recei ve 
sis u nat o vir, eit her at t he d ose of 2 0 0 m g or 3 5 0 m g q 1 2 h, or place b o f or 5 da ys. T he pri mar y 
o bjecti ve of t he st u d y was t o assess t he a nti viral acti vit y of sis u nat o vir vers us place b o fr o m 
nasal was h sa m ples b y R T- P C R fr o m pre -d ose u ntil disc har ge at Da y  1 2. Ot her o bjecti ves 
were relate d t o cli nical o utc o mes s uc h as pr o d ucti o n of nasal disc har ge a n d prese nce a n d 
d urati o n of R S V relate d s y m pt o ms, assesse d t hr o u g h a s y m pt o m sc ore m o del. Treat me nt 
wit h sis u nat o vir res ulte d i n a statisticall y  si g nifica nt re d ucti o n i n A U C of R S V viral l oa d 
c o m pare d wit h place b o; 5 5. 2 5 % ( p = 0. 0 0 7) a n d 6 3. 0 5 % ( p = 0. 0 0 2) f or t he 2 0 0 m g a n d 3 5 0 
m g sis u nat o vir d ose gr o u ps, res pecti vel y. Res ults f or t he A U C of t otal s y m pt o m sc ore were 
c o nsiste nt wit h t he viral l oa d A U C. Ge o metric mea n A U Cs of t otal s y m pt o m sc ore were 
1 9 5. 5 6, 3 0. 7 9 a n d 3 1. 7 6 h o urs x sc ore f or place b o, 2 0 0 m g sis u nat o vir a n d 3 5 0 m g 
sis u nat o vir, res pecti vely. T he re d ucti o n i n A U Cs of t ota l s ym pt o m sc ore c o m pare d wit h 
place b o was statisticall y  si g nifica nt f or b ot h sis u nat o vir treat me nt gr o u ps; p = 0. 0 0 9 ( 8 4. 2 6 %) 
a n d p = 0. 0 0 2 ( 8 3. 7 6 %), ( Wilc o x o n Ra n k S u m test) f or t he 2 0 0 m g a n d 3 5 0 m g sis u nat o vir 
d ose gr o u ps, res pecti vel y. Sis u nat o vir treat me n t res ulte d i n a statisticall y si g nifica nt 
re d ucti o n i n t he t otal wei g ht of nasal disc har ge c o m pare d wit h place b o. Least s q uares mea n 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 3 6
dail y  nasal m uc us wei g ht was si g nifica ntl y l o wer wit h sis u nat o vir 2 0 0 m g a n d 3 5 0 m g vers us 
place b o ( 0. 3 3 g, p = 0. 0 3 8 a n d 0. 2 7 g, p = 0. 0 1 0, vers us 0. 6 1 g).
T here are 7 o n g oi n g st u dies:

A P hase 1 m ulti ple site st u d y  ( C 5 2 4 1 0 1 2) t o assess t he effects of he patic i m pair me nt 
o n t he p har mac o ki netics of sis u nat o vir. 

A P hase 1 si n gle site st u d y  ( C 5 2 4 1 0 1 3) t o assess t he relati ve bi oa vailabilit y  of 
sis u nat o vir f oll o wi n g si n gle oral d ose of differe nt f or m ulati o ns u n der fe d a n d faste d 
c o n diti o ns i n healt h y a d ult partici pa nts .

A P hase 1 m ulti ple site st u d y  ( C 5 2 4 1 0 1 6) t o assess t he effects of re nal i m pair me nt o n 
t he P K of sis u nat o vir.

A P hase 1 si n gle site st u d y ( C 5 2 4 1 0 1 7) t o assess t he effects of a pr ot o n p u m p 
i n hi bit or o n t he P K of sis u nat o vir i n healt h y a d ult partici pa nts.

A P hase 1 si n gle site st u d y  ( C 5 2 4 1 0 1 8) t o assess t he P K, safety, a n d t olera bilit y  
f oll o wi n g si n gle a n d m ulti ple d oses of sis u nat o vir i n C hi nese healt h y a d ult 
partici pa nts.

A P hase 1 b m ulti ple site st u d y  ( C 5 2 4 1 0 0 9) t o assess t he safety, t olera bilit y,  a n d P K 
of sis u nat o vir i n pe diatric partici pa nts u p t o a ge 6 0 m o nt hs wit h R S V L R TI.

A P hase 2/ 3 m ulti ple site st u d y  ( C 5 2 4 1 0 0 7) t o i n vesti gate efficac y a n d safet y of oral 
sis u nat o vir c o m pare d wit h place b o i n n o n-h os pitalize d s y m pt o matic a d ults wit h R S V 
i nfecti o n w h o are at ris k of pr o gressi o n t o se vere ill ness.
I n a d ult st u dies, t he a d mi nistrati o n of sis u nat o vir was well t olerate d at all d oses, d osa ge 
f or ms a n d d osi n g re gi me ns teste d a n d t he occ urre nce of T E A Es c o nsi dere d relate d t o 
sis u nat o vir has bee n l o w. T he m ost c o m m o nl y re p orte d treat me nt relate d T E A Es i n a d ults 
were i n t he GI dis or ders S y ste m Or ga n Class: na usea, diarr hea a n d a b d o mi nal pai n. T hese 
T E A Es ha ve bee n mil d t o m o derate i n i nte nsit y  a n d res ol ve d wit h o ut se q uelae.
As of 2 0 Ja n uar y  2 0 2 4, t here were n o S A Es attri b uta ble t o sis u nat o vir a n d n o deat hs i n t he 
cli nical st u dies. T here has bee n 1 seri o us A E of fe ver re p orte d i n t he pe diatric st u d y  
( C 5 2 4 1 0 0 3) i n a c hil d h os pitalize d wit h R S V i nfecti o n w h o recei ve d a si n gle d ose of 
sis u nat o vir. T his was c o nsi dere d seri o us beca use it pr ol o n ge d h os pitalizati o n, b ut t he S A E 
was re p orte d as n ot relate d t o I M P. I n C 5 2 4 1 0 0 2 t here was 1
S A E of s u b -ac ute m yocar ditis 
re p orte d f or a s u bject o n place b o; t his was c o nsi dere d t o be ca usally relate d t o t he c halle n ge 
vir us. 
I n a d ults, sis u nat o vir is sl o wl y a bs or be d, reac hi n g ma xi m u m plas ma c o nce ntrati o ns (T ma x ) at 
 h o urs wit h a half-life of
h o urs i n healt h y partici pa nts. D osi n g t o stea d y state 
res ulte d i n stea dy state c o nce ntrati o ns bei n g reac he d after a p pr o xi matel y
da ys of d osi n g 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI C CI
C CI

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
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Page 38
2.3. Benefit/Risk Assessment
The sisunatovir preclinical profile, as well as the efficacy, safety, and tolerability data from 
the initial human studies, provide a strong rationale for the clinical development of 
sisunatovir.
More detailed information about the known and expected benefits and risks and reasonably 
expected AEs of sisunatovir may be found in the IB, which is the SRSD for this study. Refer 
to the Study Intervention(s) table in Section 6.1 for a complete description of SRSDs. 
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 3 9
2. 4. Ris k Assess me nt
P ote nti al Ris k of 
Cli nic al Si g nific a nce
S u m m ar y of D at a/ R ati o n ale f or Ris k
Miti g ati o n Str ate g y
St u d y I nter ve nti o n(s) [ Sis u n at o vir] 
He pat o biliar y s yste m 
effects
I n c o m plete d cli nical st u dies, mil d tra nsie nt as y m pt o matic ele vati o ns of li ver e nz y mes ha ve bee n 
o bser ve d i n a fe w partici pa nts. 
Safet y m o nit ori n g i ncl u di n g la b orat or y (ie, 
tra nsa mi nases, G G T) a n d A E m o nit ori n g. 
E xcl usi o n of patie nts wit h acti ve li ver 
disease or li ver f u ncti o n i m pair me nt. ( E C # 9).
Gastr oi ntesti nal 
effects
I n c o m plete d a d ult cli nical st u dies sis u nat o vir has bee n ass ociate d wit h mil d t o m o derate GI A Es.
Partici pa nts will be cl osel y e val uate d t o 
m o nit or f or GI A Es. 
Car di o vasc ular 
effects
T o date, P hase 1 st u dies i n healt h y partici pa nts a n d a st u d y i n pe diatric partici pa nts has n ot s h o w n 
cli nicall y si g nifica nt c ha n ges i n safet y la b orat or y para meters (i ncl u di n g tr o p o ni n i n C 5 2 4 1 0 0 1), E C Gs 
a n d vital si g ns relate d t o sis u nat o vir.
A
w as c o n d ucte d t o assess t he ef fect of sis u nat o vir o n Q T 
i nter val. T here was 
of t he
at  
 
 of sis u nat o vir wit h 
M o nit ori n g will i ncl u de vital si g ns, i ncl u di n g 
heart rate, a n d baseli ne a n d f or c a use E C G 
assess me nts.
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 40
2.4.1. Benefit Assessment
In the virus challenge study, sisunatovir was found to significantly reduce the nasal RSV 
viral load in healthy volunteers, with consequent early recovery of symptoms. These findings 
may translate to direct clinical benefit in patients who acquire the infection naturally and are 
at increased risk of developing severe illness, due to the presence of older age, 
cardiopulmonary comorbidities and compromised immune system. 
Participation in this study may also lead to improved knowledge about RSV and help develop 
new treatments that could benefit society.
Frequent medical evaluations, vital signs collection, blood tests and other assessments may 
also lead to improved health outcomes for participants. 
2.4.2. Overall Benefit/Risk Conclusion
Considering the high prevalence of RSV, its potential negative impact on the morbidity and 
mortality of individuals at increased risk of severe illness and the financial burden on the 
health systems worldwide, taken together, the expected benefits of receiving sisunatovir for 
the treatment of RSV outweigh the risks of trial participation and those associated with the 
potential toxicity of sisunatovir identified in the early stage of development. 
3. OBJECTIVES, ENDPOINTS, AND ESTIMANDS
All objectives, endpoints, and estimands will be evaluated in non-hospitalized adults who are 
infected with RSV and are at high risk of severe illness. The treatment effect is evaluated in 
the population of study participants who are randomized and treated irrespective of their 
compliance to the planned course of treatment or use of concomitant medications (see 
Section 9.1.1). The primary analysis and key secondary analyses are conducted in adults with 
confirmed RSV infection. 
Objectives
Endpoints
Estimands
Primary:
! To compare the efficacy of 
sisunatovir to placebo for 
treatment of RSV among 
non-hospitalized adults at 
high risk for severe illness.
! Proportion of participants with 
RSV-related hospitalization or 
death from any cause through Day 
28.
! The difference in treatment proportions 
of patients experiencing RSV-related 
hospitalization or death from any cause 
through Day 28. 
Key Secondary:
!
To compare the efficacy of 
sisunatovir to placebo for 
treatment of RSV among 
non-hospitalized adults at 
high risk for severe illness.
! Proportion of participants with 
RSV-related visits (urgent 
care/ED/hospital) or death from any 
cause through Day 28.
! The difference in treatment proportions 
of patients experiencing RSV-related 
visits (urgent care/ED/hospital) or death 
from any cause through Day 28. A 
hospital visit of any duration will be 
included. 
! Proportion of participants with 
progression of LRTI through 
Day 10.
! The difference in treatment proportions 
of patients with progression of LRTI 
through Day 10 will be evaluated in the 
population of participants who do not 
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
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Objectives
Endpoints
Estimands
have RSV-related severe LRTI (sLRTI-
RSV) at randomization. 
! Proportion of participants with 
development of LRTI through 
Day 10.
! The difference in treatment proportions 
of patients who develop sLRTI-RSV or 
nsLRTI-RSV through Day 10 will be 
evaluated in the population of 
participants who do not have sLRTI-RSV 
or nsLRTI-RSV at randomization.
! Proportion of participants with 
resolution of LRTI at Day 15.
! The difference in treatment proportions 
of patients with resolution of LRTI at 
Day 15 will be evaluated in the 
population of participants who have 
sLRTI-RSV or nsLRTI-RSV at 
randomization.
! Mean number of days alive and free 
from hospital stay (hospital-free 
days) through Day 28.
! The difference in treatment means of 
number of days alive and free from 
hospital stay (hospital-free days) through 
Day 28.
Other Secondary:
! To compare the efficacy of 
sisunatovir to placebo for 
treatment of RSV among 
non-hospitalized adults at 
high risk for severe illness.
! Proportion of participants with 
progression of LRTI through Day 3, 
5, 15, and 28.
! The difference in treatment proportions 
of patients with progression of LRTI 
through Day 3, 5, 15, and 28 will be 
evaluated in the population of 
participants who do not have sLRTI-RSV 
at randomization. 
! Proportion of participants with 
development of LRTI through Day 
3, 5, 15, and 28.
! The difference in treatment proportions 
of patients who develop sLRTI-RSV or 
nsLRTI-RSV through Day 3, 5, 15, and 
28 will be evaluated in the population of 
participants who do not have sLRTI-RSV 
or nsLRTI-RSV at randomization.
! Proportion of participants with 
resolution of LRTI at Day 3, 5, 10, 
and 28.
! The difference in treatment proportions 
of patients with resolution of LRTI at 
Day 3, 5, 10, and 28 will be evaluated in 
the population of participants who have 
sLRTI-RSV or nsLRTI-RSV at 
randomization. 
! Proportion of participants with 
improvement in LRTI status at Day 
3, 5, 10, 15, and 28.
! The difference in treatment proportions 
of patients with improvement in LRTI 
status at Day 3, 5, 10, 15, and 28 will be 
evaluated in the population of 
participants who have sLRTI-RSV or 
nsLRTI-RSV at randomization. 
! Number of RSV related days in 
hospital through Day 28.
! Number of RSV related days in ICU 
through Day 28.
! The difference in treatment means of 
number of RSV related days in hospital 
and separately, number of RSV related 
days in ICU, through Day 28.
! Proportion of participants with a 
clinical response of Improvement or 
Resolution at Day 5, 10, 15, and 28.
! The difference in treatment proportions 
of patients with Improvement or 
Resolution at Day 5, 10, 15, and 28.
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
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Page 42
Objectives
Endpoints
Estimands
! To compare NP viral load 
changes among non-
hospitalized adults at high 
risk for severe illness treated 
with sisunatovir relative to 
placebo.
! Proportion of participants with 
undetectable RSV viral load at each 
study visit through Day 28.
! Change from baseline in RSV viral 
load at each study visit through 
Day 28.
! The difference in treatment proportions 
of patients with undetectable RSV viral 
load at each visit through Day 28 
! The difference in treatment means of 
change from baseline in RSV viral load 
at each study visit through Day 28.
! To describe the safety and 
tolerability of sisunatovir 
relative to placebo among 
non-hospitalized adults at 
high risk for severe illness.
! Proportion of participants with 
TEAEs through Day 35.
! Proportion of participants with 
SAEs through Day 35.
! NA.
! To determine the PK of 
sisunatovir among non-
hospitalized adults at high 
risk for severe illness.
! Plasma concentrations of 
sisunatovir at steady state (Day 3 or 
later).
! NA.
Tertiary / Exploratory
! To describe treatment 
emergent resistance to 
sisunatovir or fusion 
inhibitor class and its impact 
on viral load and clinical 
outcomes.
! Proportion of participants with post 
baseline changes in RSV F gene 
sequence that confer resistance to 
sisunatovir or fusion inhibitor class.
! Change from baseline in viral load 
in participants with or without 
changes in RSV F gene sequence 
that confer resistance to sisunatovir 
or fusion inhibitor class.
! Proportion of participants with 
RSV-related hospitalization or 
death from any cause through Day 
28, in participants with and without
post baseline changes in RSV F 
gene sequence that confer resistance 
to sisunatovir or fusion inhibitor 
class.
! NA.
! To describe changes in 
patient reported outcomes 
between sisunatovir and 
placebo arms.
! Change from baseline at Day 3, 5, 
10, 15 and 28 in EQ-5D-5L scale.
! NA.
! To explore RSV recurrence 
in the sisunatovir and 
placebo arms.
! Proportion of participants with RSV 
recurrence at Day 10, 15 and 28.
! NA.
! To describe onward 
transmission in households 
between sisunatovir and 
placebo arms.
! The proportion of household 
contacts with confirmed or 
suspected ARI (symptomatic 
transmission) through Day 3, 5, 10, 
15, and 28.
! The proportion of household 
contacts who become infected with 
confirmed RSV (virological 
transmission) through Day 3, 5, 10, 
15, and 28.
! NA.
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
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recommendations will be reviewed by the Sponsor Management Committee and a 
determination will be made regarding continuation or cessation of randomization into the 
study.
The total study duration is up to 5 weeks and includes a screening period of 1-2 days where 
randomization (Day 1) must occur by the second consecutive day, study intervention 
administration through Day 5, efficacy outcome assessments through Day 28, and a safety 
follow-up period through Day 35.
An external data monitoring committee (E-DMC) will review blinded and unblinded data to 
ensure the safety of participants on an ongoing basis throughout the entire duration of the 
study. The E-DMC will also review data from each of the two planned efficacy IAs, as 
specified in the E-DMC Charter.
When the PK IA is performed, an internal, independent, unblinded review committee 
separate from the study team will review population PK model-derived plasma 
concentration-time curves and PK parameters for sisunatovir. No safety or efficacy data will 
be used to inform the PK IA.
Participants in the United States will be invited to participate in optional, additional research 
using real world data to describe long-term health outcomes and healthcare utilization (see 
Section 10.10.1).
4.2. Scientific Rationale for Study Design
The choice of the current study design (randomized, double blind, superiority with 2 parallel 
arms) allows for a direct and unbiased statistical comparison between sisunatovir and placebo 
groups. 
4.2.1. Rationale for end point selection.
The primary end point of hospitalization, defined as ≥24 hours of acute care in a hospital or 
similar acute care facility, or death by Day 28 reflects the poor clinical outcomes experienced 
by patients that progress to severe illness, and it has been agreed in consultation with 
regulatory agencies.
Secondary end points of LRTI and medically attended visits have been selected based on 
evidence from medical literature of disease progression and burden on health systems 
globally.
4.2.2. Rationale for Study Population
The population includes adult individuals with cardiopulmonary comorbidities and 
compromised immune system and older adults who are described in the medical literature as 
being at increased risk of hospitalization and death and in most need for safe and effective 
treatments. 
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 4 5
Selecti o n of partici pa nts wit h a s y m pt o m d urati o n of ≤5 da y s is bei n g i m ple me nte d d ue t o 
earl y data fr o m cli nical trials of ot her R S V F pr otei n i n hi bit ors i n de vel o p me nt [1 2 ,1 3 ]. 
4. 2. 3. Di versit y of St u d y P o p ul ati o n
T he di versit y  strate g y will i ncl u de sites wit h t he p ote ntial t o s u p p ort t he recr uit me nt of 
di verse p o p ulati o ns acr oss ge o gra p hicall y  di verse c o u ntries. Reas o na ble atte m pts will be 
ma de t o e nr oll partici pa nts t hat are re prese ntati ve of t he patie nt p o p ulati o n t hat will be 
treate d wit h sis u nat o vir i n cli nical practice.
4. 2. 4. R ati o n ale f or C o m p ar at or 
Place b o will be use d i n t his trial as a c o m parat or t o all o w f or a n u n biase d e val uati o n of t he 
safety a n d efficac y of sis u nat o vir. T he use of place b o is j ustifie d b y t he lac k of a p pr o ve d 
R S V s pecific treat me nts.
4. 2. 5. R ati o n ale f or A d a pti ve or N o vel St u d y Desi g n 
At t he ti me of pla n ni n g t he P hase 2/ 3 st u d y , t here was u ncertai nt y a b o ut t he rate of R S V 
relate d h os pitalizati o n or deat h i n t he pri mar y a nal ysis p o p ulati o n, a n d a b o ut t he treat me nt 
effect of sis u nat o vir. T he pla n ne d efficac y I As (i ncl u di n g sa m ple size re-assess me nt) all o w 
f or earl y st o p pi n g of t he trial d ue t o f utilit y or earl y efficac y or all o w f or i ncreasi n g t he 
sa m ple size. 
4. 2. 6. C h oice of C o ntr ace pti o n/ B arrier Re q uire me nts 
H u ma n re pr o d ucti ve safet y  data are li mite d f or sis u nat o vir, b ut t here is n o s us pici o n of 
h u ma n terat o ge nicit y base d o n t he i nte n de d p har mac ol o g y of t he c o m p o u n d. T heref ore, t he 
use of a hi g hl y effecti ve met h o d of c o ntrace pti o n is re q uire d f or fe male partici pa nts of 
c hil d beari n g p ote ntial (see S o A a n d Secti o n 1 0. 4 ).
4. 3. J ustific ati o n f or D ose
T o i n vesti gate t he effect of sis u nat o vir o n cli nical acti vit y  f oll o wi n g R S V i nfecti o n, a viral 
c halle n ge cli nical st u d y i n healt h y a d ult partici pa nts was c o n d ucte d w here d oses of 2 0 0 m g 
or 3 5 0 m g q 1 2 h x 5 da y s were a d mi nistere d f oll o wi n g c o nfir mati o n of a n R S V i nfecti o n p ost 
i n oc ulati o n ( C 5 2 4 1 0 0 2). W hile t here was n ot a cli nicall y mea ni n gf ul differe nce bet wee n 2 0 0 
a n d 3 5 0 m g sis u nat o vir (see Secti o n 2. 2. 4 ), a n i ncrease d i nci de nce of GI A Es was o bser ve d 
at t he 3 5 0 m g d ose relati ve t o t he 2 0 0 m g d ose, u n der fasti n g c o n diti o ns. Hi g her rates of GI 
A Es were als o o bser ve d at hi g her d oses wit hi n t he P hase 1 pr o gra m (i n t he faste d state). A 
p o p ulati o n e x p os ure -safet y m o del of sis u nat o vir i n dicates a d mi nistrati o n of t he
m g d ose 
has a l o wer pr o ba bilit y  of e x perie nci n g 
(
%), 
 (
%), a n d
(
%), as c o m pare d t o t he  
m g d ose  
%,  
%, a n d  
%, res pecti vely). A d diti o nall y , 
a d mi nistrati o n of  
m g u n der fe d state re d uces t he pr o ba bilit y  of e x perie nci n g 
v s  
%). Preli mi nar y res ults fr o m C 5 2 4 1 0 0 6 de m o nstrate d t hat t he  
m g 
sis u nat o vir d ose u n der fe d c o n diti o ns res ulte d i n e x p os ure a b o ve N O A E L li mits, w hereas 
e x p os ures ass ociate d wit h  
m g 
fasti n g a n d fe d were c o nsiste nt wit h t h ose o bser ve d 
i n pre vi o us st u dies. Base d o n t hese fi n di n gs, t he  
m g  
d ose t hat was f o u n d t o 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 4 6
ma xi mize efficac y  w hile mai ntai ni n g safety, t olera bilit y  a n d e x p os ures bel o w N O A E L will 
be e val uate d i n t his st u d y. T o vali date t he pr o p ose d d ose re gi me n i n a d ults, a viral d y na mics 
Q S P m o del was de vel o pe d fr o m i n vitr o Pla q ue Assa y  E C9 0 data i nf or mi n g Cli nical E C 9 0, 
sis u nat o vir P K i nf or mi n g cli nical e x p os ure, a n d viral c halle n ge data i nf or mi n g viral 
d y na mics. Si m ulati o ns i n dicate d t hat t here was n o a d diti o nal be nefit of l oa d i n g d oses or 
m ore t ha n 5 da y s of treat me nt o n re d ucti o n of viral l oa d A U C. A d diti o nall y, d oses bel o w 
m g were pre dicte d t o ha ve atte n uate d re d ucti o n of viral l oa d A U C.
4. 4. E n d of St u d y Defi niti o n
T he e n d of t he st u d y is defi ne d as t he date of t he last sc he d ule d visit ( Da y  3 5) of t he last 
partici pa nt i n t he st u d y  or t he last sc he d ule d pr oce d ure s h o w n i n t he S o A f or t he last 
partici pa nt i n t he trial gl o ball y .
A partici pa nt is c o nsi dere d t o ha ve c o m plete d t he st u d y  if t he y ha ve c o m plete d all peri o ds of 
t he st u d y, i ncl u di n g t he last sc he d ule d visit ( Da y 3 5) s h o w n i n t he S o A .
5. S T U D Y P O P U L A TI O N
T his st u d y  ca n f ulfill its o bjecti ves o nl y if a p pr o priate partici pa nts are e nr olle d, i ncl u di n g 
partici pa nts acr oss di verse a n d r e prese ntati ve racial a n d et h nic bac k gr o u n ds. If a 
prescree ni n g t o ol is utilize d f or st u d y recr uit me nt p ur p oses, it will i ncl u de c ollecti o n of 
i nf or mati o n t hat reflects t he e nr oll me nt of a di verse partici pa nt p o p ulati o n i ncl u di n g, w here 
per mitte d u n der l oca l re g ulati o ns, a ge, se x, race, a n d et h nicit y. T he f oll o wi n g eli gi bilit y  
criteria are desi g ne d t o select partici pa nts f or w h o m partici pati o n i n t he st u d y  is c o nsi dere d 
a p pr o priate. All rele va nt me dical a n d n o n me dical c o n diti o ns s h o ul d be ta ke n i nt o 
c o nsi derati o n w he n deci di n g w het her a partic ular partici pa nt is s uita ble f or t his pr ot oc ol. 
Pr os pecti ve a p pr o val of pr ot oc ol de viati o ns t o recr uit me nt a n d e nr oll me nt criteria, als o 
k n o w n as pr ot oc ol wai vers or e xe m pti o ns, is n ot per mitte d.
5. 1. I ncl usi o n Criteri a
Partici pa nts are eli gi ble t o be i ncl u de d i n t his st u d y  o nl y if all of t he f oll o wi n g criteria a p ply:
A ge a n d Se x:
1.
Partici pa nts a ge d 1 8 ye ars or ol der ( or t he mi ni m u m a ge of c o nse nt, if a b o ve 1 8, i n 
acc or da nce wit h l ocal re g ulati o ns) at scree ni n g.

W o me n of c hil d beari n g p ote ntial m ust a gree t o use hi g hl y effecti ve c o ntrace pti o n. 
Refer t o A p pe n di x 4 ( Secti o n 1 0. 4. 3 a n d 1 0. 4. 4 ) f or re pr o d ucti ve criteria f or fe male 
partici pa nts.
Dise ase C h ar acteristics:
2.
Dia g n osis of R S V i nfecti o n, as deter mi ne d b y a p ositive R T -P C R, ra pi d a nti ge n test, or 
ot her l ocall y a vaila ble dia g n ostic test i n a n y res pirat or y s peci me n (e g, nasal, 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 47
nasopharyngeal swab, sputum) collected within 5 days of randomization. Randomization 
must occur no later than the 5th day since the diagnosis of RSV infection where the day of 
RSV diagnosis is the 1st day.
3. New onset or worsening (if present chronically) of at least one of the following signs 
and/or symptoms consistent with a viral acute respiratory infection (ARI), within 5 days 
prior to randomization: nasal congestion, nasal discharge, sore throat, cough, sputum 
production, shortness of breath, or wheezing. Randomization must occur no later than the 
5th day, where the day of onset/worsening is the 1st day. 
Other Inclusion Criteria:
4. Has at least 1 of the following characteristics or underlying medical conditions:
!
65 years of age or older.
!
Chronic lung disease that is symptomatic or requiring treatment, including but not 
limited to: COPD, asthma, CF, PF, PAH, alpha-1 anti-trypsin deficiency, or 
pulmonary sarcoidosis. 
!
Heart failure (functional class II-IV according to NYHA classification).
!
Immunosuppressive disease or condition (eg, hematological malignancy, CAR-T, 
bone marrow or organ transplant recipient, primary immune deficiency, or HIV 
infection with CD4+ cell count <200 / μL within the last 6 months) OR use of at least 
1 of the following immune-weakening medications: 
o
Recent treatment with corticosteroids equivalent to prednisone ≥20 mg daily for 
at least 14 consecutive days, all of which must have been within the last 30 days 
prior to study entry OR are currently receiving ≥20 mg daily that must have been 
administered for at least 14 consecutive days at the time of study entry.
o
Active treatment causing significant immunosuppression, including alkylating 
agents, antimetabolites, transplant-related immunosuppressive drugs, cancer 
chemotherapeutic agents, TNF blockers, or other highly immunosuppressive 
drugs such as biologics (eg, ustekinumab, anti-CD20).
5.2. Exclusion Criteria
Participants are excluded from the study if any of the following criteria apply:
Medical Conditions:
1. Any medical (eg, confirmed concurrent active systemic infection other than RSV 
including bacterial, fungal, or viral) or psychiatric condition including recent (within the 
past year) or active suicidal ideation/behavior or laboratory abnormality that may 
increase the risk of study participation or, in the investigator’s judgment, make the 
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 48
participant inappropriate for the study or interfere with the evaluation of response to the 
study intervention.
2. Diagnosis of viral respiratory infections other than RSV including influenza and SARS-
CoV-2, within 7 days of randomization. A negative test for SARS-CoV-2 and influenza 
is required within 7 days of randomization.
3. Current need for hospitalization or anticipated need for hospitalization for any reason to 
provide inpatient/acute care within 24 hours after randomization in the clinical opinion of 
the site investigator.
4. Any clinically significant ECG abnormality in the pre-dose ECG that, per investigator 
judgement, may affect participant safety.
Prior/Concomitant Therapy:
5. Current or recent use of any prohibited concomitant medication(s) that may result in a 
clinically significant drug-drug interaction (see Section 10.9 for details).
6. Use of oral or inhaled ribavirin in prior 30 days or anticipated use during the study. 
Prior/Concurrent Clinical Study Experience:
7. Prior administration of study drug in a sisunatovir trial, recent administration of an 
investigational drug or vaccine (within 30 days or 5 half-lives), or concurrent 
participation in a study of another investigational drug or vaccine.
Diagnostic Assessments:
8. Renal impairment defined by an eGFR <30 mL/min/1.73 m2 or receiving dialysis.
9. Active liver disease with AST or ALT >3 ULN, Total bilirubin ≥2 × ULN (For Gilbert’s 
syndrome, direct bilirubin >ULN is exclusionary) within the past 3 months, or liver 
function impairment with Class B or C per Child Pugh classification.
Other Exclusion Criteria:
10. Has hypersensitivity to or other contraindication to any of the components of the study 
interventions, as determined by the investigator.
11. Investigator site staff directly involved in the conduct of the study and their family 
members, site staff otherwise supervised by the investigator, and sponsor and sponsor 
delegate employees directly involved in the conduct of the study and their family 
members.
090177e1a08f5ab3\Approved\Approved On: 30-Apr-2024 17:12 (GMT)

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 4 9
5. 3. Lifest yle C o nsi der ati o ns
5. 3. 1. C o ntr ace pti o n 
T he i n vesti gat or or t heir desi g nee, i n c o ns ultati o n wit h t he p artici pa nt, will c o nfir m t hat t he 
partici pa nt is utilizi n g a n a p pr o priate met h o d of c o ntrace pti o n f or t he i n di vi d ual partici pa nt 
fr o m t he per mitte d list of c o ntrace pti o n met h o ds (see A p pe n di x 4 , Secti o n 1 0. 4. 4 ) a n d will 
c o nfir m t hat t he partici pa nt has bee n i nstr ucte d i n its c o nsiste nt a n d c orrect use. 
At ti me p oi nts i n dicate d i n t he S o A , t he i n vesti gat or or desi g nee will i nf or m t he partici pa nt 
of t he nee d t o use hi g hl y effecti ve c o ntrace pti o n c o nsiste ntl y a n d c orrectl y a n d d oc u me nt t he 
c o n versati o n a n d t he partici pa nt’s affir mati o n i n t he partici pa nt’s c hart. Partici pa nts nee d t o 
affir m t heir c o nsiste nt a n d c orrect use of at least 1 of t he selecte d met h o ds of c o ntrace pti o n, 
c o nsi deri n g t hat t heir ris k f or pre g na nc y  ma y ha ve c ha n ge d si nce t he last visit. 
I n a d diti o n, t he i n vesti gator or desi g nee will i nstr uct t he partici pa nt t o call i m me diatel y  if t he 
selecte d c o ntrace pti o n met h o d is disc o nti n ue d a n d d oc u me nt t he re q uire me nt t o use a n 
alter nate pr ot oc ol-s pecifie d met h o d, i ncl u di n g if t he partici pa nt will n o l o n ger use a bsti ne nce 
as t he selecte d c o ntrace pti o n met h o d, or if pre g na nc y is k n o w n or s us pecte d i n t he partici pa nt 
or part ner.
5. 4. Pre -scree ni n g c o nse nt a n d pre-scree ni n g vir al testi n g ( o pti o n al, if a p plic a ble)
S o me patie nts wit h A RI  w h o are at ris k of pr o gressi o n t o se vere ill ness ma y  n ot ha ve r o uti ne 
me dical access t o ra pi d R S V testi n g. F or t hese patie nts, access t o a ra pi d R S V test w o ul d 
hel p deter mi ne if t his patie nt ma y  be eli gi ble t o e nr oll i n t his cli nical st u d y a n d a n o pti o nal 
pre -scree ni n g visit ma y be c o n d ucte d. O nce pre-s cree ni n g i nf or me d c o nse nt is o btai ne d, a 
s p o ns or-s u p p orte d pre-scree ni n g viral test will be perf or me d. I n a d diti o n t o testi n g f or R S V, 
t he pre-scree ni n g viral test ma y als o test f or S A R S-C o V -2 a n d/ or i nfl ue nza.
Partici pa nts m ust meet all of t he f oll o wi n g cr iteria t o be eli gi ble f or a pre-scree ni n g visit:

Partici pa nt has n ot u n der g o ne a n R S V test f or t his A RI  e pis o de. 

Partici pa nt is a ge d 1 8 ye ars or ol der ( or t he mi ni m u m a ge of c o nse nt, if a b o ve 1 8, i n 
acc or da nce wit h l ocal re g ulati o ns).

Ne w o nset or w orse ni n g (if prese nt c hr o nicall y) of at least o ne of t he f oll o wi n g si g ns 
a n d/ or s ym pt o ms c o nsiste nt wit h a viral A RI, wit hi n 5 da ys of pre -scree ni n g: nasal 
c o n gesti o n, nasal disc har ge, s ore t hr oat, c o u g h, s p ut u m pr o d ucti o n, s h ort ness of breat h, 
or w heezi n g. If the st u d y meets t he  
% e nr ol me nt li mit f or patie nts ra n d o mize d da y s 
fr o m s ym pt o m o nset, t he n t he a b o ve criteria will be li mite d t o wit hi n 4 da y s of s ym pt o m 
o nset.
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 5 0

Has at least 1 of t he f oll o wi n g c haracteristics or u n derl yi n g me dical c o n diti o ns:

6 5 y ears of a ge or ol der. If t he st u d y  meets t he
% e nr ol me nt li mit f or partici pa nts 
≥6 5 y ears of a ge wit h n o ne of t he ot her ris k fact ors t hat are liste d as i ncl usi o n criteria, 
t he n t he a ge criteri o n al o ne ca n n o l o n ger be use d t o deter mi ne eli gi bilit y f or pre-
scree ni n g viral testi n g.

C hr o nic l u n g disease t hat is s y m pt o matic or re q uiri n g treat me nt, i ncl u di n g b ut n ot 
li mite d t o: C O P D, ast h ma, C F, P F, P A H, al p ha-1 a nti -tr ypsi n deficie nc y , or 
p ul m o nar y  sarc oi d osis. 

Heart fail ure (f u ncti o nal class II -I V acc or di n g t o N Y H A classificati o n).

I m m u n os u p pressi ve disease or c o n diti o n (e g, he mat ol o gical mali g na nc y, C A R-T, 
b o ne marr o w or or ga n tra ns pla nt reci pie nt, pri mar y i m m u ne deficie nc y , or HI V 
i nfecti o n wit h C D 4 + cell c o u nt < 2 0 0 / µ L wit hi n t he last 6 m o nt hs) O R use of at least 
1 of t he f oll o wi n g i m m u ne -wea ke ni n g me dicati o ns: 
o
Rece nt treat me nt wit h c ortic oster oi ds e q ui vale nt t o pre d nis o ne ≥2 0 m g dail y
f or at least 1 4 c o nsec uti ve da ys, all of w hic h m ust ha ve bee n wit hi n t he last 3 0 
da y s pri or t o st u d y e ntr y O R are c urre ntly recei vi n g ≥2 0 m g daily t hat m ust
ha ve bee n a d mi nistere d f or at least 1 4 c o nsec uti ve da y s at t he ti me of st u d y 
e ntr y.
o
Acti ve treat me nt ca usi n g si g nifica nt i m m u n os u p pressi o n, i ncl u di n g al k yl ati n g 
a ge nts, a nti meta b olites, tra ns pla nt -relate d i m m u n os u p pressi ve dr u gs, ca ncer 
c he m ot hera pe utic a ge nts, T N F bl oc kers, or ot her hi g hl y i m m u n os u p pressi ve 
dr u gs s uc h as bi ol o gics (e g, uste ki n u ma b, a nti -C D 2 0).
5. 5. Scree n F ail ures
Scree n fail ures are defi ne d as partici pa nts w h o c o nse nt t o partici pate i n t he cli nical st u d y  b ut 
are n ot s u bse q ue ntl y ra n d o mize d i n t he st u d y. A mi ni mal set of scree n fail ure i nf or mati o n is 
re q uire d t o e ns ure tra ns pare nt re p orti n g of scree n fail ure partici pa nts t o meet t he C O N S O R T 
p u blis hi n g re q uire me nts a n d t o res p o n d t o q ueries fr o m re g ulat or y a ut h ori ties. Mi ni mal 
i nf or mati o n i ncl u des de m o gra p hy,  scree n fail ure details, a n d a ny S A E.
I n di vi d uals w h o d o n ot meet t he criteria f or partici pati o n i n t his st u d y (scree n fail ure) ma y 
n ot be rescree ne d f or 3 0 da y s (ie, t he y ma y be rescree ne d d uri n g t he f oll o wi n g R S V seas o n if 
t he y re prese nt wit h a ne w i nfecti o n).
6. S T U D Y I N T E R V E N TI O N( S ) A N D C O N C O MI T A N T T HE R A P Y
St u d y  i nter ve nti o ns are all pres pecifie d i n vesti gati o nal a n d n o n-i n vesti gati o nal me dici nal 
pr o d ucts, me dical de vices, a n d ot her i nter ve nti o ns (e g, s ur gical a n d be ha vi oral) i nte n de d t o 
be a d mi nistere d t o t he st u d y partici pa nts d uri n g t he st u d y  c o n d uct. 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 5 1
F or t he p ur p oses of t his pr ot oc ol, st u d y  i nter ve nti o n refers t o sis u nat o vir a n d place b o. 
6. 1. St u d y I nter ve nti o n(s) A d mi nistere d
St u d y I nter ve nti o ns
I nter ve nti o n N a me
Sis u nat o vir  
m g
Place b o
T y pe
Dr u g
Dr u g
Use
E x peri me ntal
Place b o
I M P or NI M P/ A x M P
I M P
I M P
D ose F or m ul ati o n
Ta blet
Ta blet
U nit D ose Stre n gt h(s)
1 0 0 m g 
0 m g
D os a ge Le vel(s)
 m g 
Place b o f or  
m g 
R o ute of 
A d mi nistr ati o n
Oral
Oral
S o urci n g
Pr o vi de d ce ntrall y b y 
t he s p o ns or
Pr o vi de d ce ntrall y b y t he s p o ns or 
P ac k a gi n g a n d 
L a beli n g
St u d y i nter ve nti o n will 
be pr o vi de d i n a b ottle. 
Eac h b ottle w ill be 
la bele d as re q uire d per 
c o u ntr y re q uire me nt.
Bli n de d.
St u d y i nter ve nti o n will be pr o vi de d i n a b ottle. Eac h 
b ottle w ill be la bele d as re q uire d per c o u ntr y 
re q uire me nt.
Bli n de d.
S R S D
I B
N A
C urre nt/ F or mer 
N a m e(s) or Ali as(es)
R V 5 2 1, P F -0 7 9 2 3 5 6 8
Place b o
St u d y Ar m(s)
A r m  Title
Sis u nat o vir
Place b o
A r m  Descri pti o n
Partici pa nts will recei ve 
ta blets of 1 0 0 m g of 
sis u nat o vir 
 fr o m 
D a y  1 t o Da y 5 (
d oses)
Partici pa nts will recei ve  
matc hi n g place b o ta blets 
fr o m Da y 1 t o Da y 5 ( 
d oses).
6. 1. 1. A d mi nistr ati o n
Partici pa nts will be dis pe nse d 1 b ottle of sis u nat o vir or matc hi n g pla ce b o. Partici pa nts will 
ta ke
ta blets of sis u nat o vir or matc hi n g place b o e ver y 
( d ose of  
m g; 
t otal dail y d ose of  
m g) f or a t otal of  
d oses ( 5 da ys or 6 da ys if o nly o ne d ose was 
ta ke n o n Da y 1). 
Partici pa nts s h o ul d ta ke t he fir st d ose of st u d y i nter ve nti o n o n Da y 1, prefera bl y d uri n g t he 
i n- pers o n visit or as s o o n as p ossi ble after ra n d o mizati o n. T o all o w t he partici pa nt t o select a 
c o n ve nie nt
 d osi n g sc he d ule, ti mi n g of d osi n g f or t he sec o n d d ose ma y be a dj uste d 
sli g htl y b ut s h o ul d be ta ke n at least  
b ut n o later t ha n  
 after t he first d ose. T he 
re mai ni n g d oses s h o ul d be ta ke n e ver y 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 5 2
Partici pa nts will s wall o w t he st u d y  i nter ve nti o n w h ole a n d will n ot ma ni p ulate or c he w t he 
st u d y i nter ve nti on pri or t o s wall o wi n g. Partici pa nts s h o ul d ta ke t he st u d y  i nter ve nti o n  
 
 Refer t o 
t he IP Ma n ual f or a d diti o nal d osi n g a n d a d mi nistrati o n i nstr ucti o ns. W het her or n ot t he 
partici pa nt ha d
 bef ore ta ki n g st u d y i nter ve nti o n will be c ollecte d.
If a d ose is dela ye d, it s h o ul d be ta ke n as s o o n as p ossi ble, b ut n o later t ha n  
bef ore 
t he ne xt sc he d ule d d ose. Partici pa nts s h o ul d n ot d o u ble u p t he ne xt d ose of st u d y dr u g t o 
“ ma ke u p” w hat ha d bee n misse d. D osi n g s h o ul d be st o p pe d at t he e n d of t he treat me nt 
peri o d  
 d oses t otal). A n y re mai ni n g ta blets at t he e n d of 5 da y s ( or 6 da ys if o nl y o ne d ose 
was a d mi nistere d o n Da y 1) m ust be ret ur ne d at t he ne xt st u d y  visit.
6. 1. 2. Me dic al De vices
N ot a p plica ble.
6. 2. Pre p ar ati o n, H a n dli n g, St or a ge, a n d Acc o u nt a bilit y
1.
T he i n vesti gat or or desi g nee m ust c o nfir m t hat a p pr o priate c o n diti o ns (e g, te m perat ure) 
ha ve bee n mai ntai ne d d uri n g tra nsit f or all st u d y  i nter ve nti o ns recei ve d a n d a n y 
discre pa ncies are re p orte d a n d res ol ve d bef ore use of t he st u d y  i nter ve nti o n. 
2.
O nl y  partici pa nts e nr olle d i n t he st u d y ma y recei ve st u d y i nter ve nti o n a n d o nl y 
a ut h orize d site staff ma y  s u p pl y, pre pare, a n d/ or a d mi nister st u d y i nter ve nti o n. 
3.
All st u d y  i nter ve nti o ns m ust be st ore d i n a sec ure, e n vir o n me ntall y c o ntr olle d, a n d 
m o nit ore d ( ma n ual or a ut o mate d rec or di n g) area i n acc or da nce wit h t he la bele d st ora ge 
c o n diti o ns wit h access li mite d t o t he i n vesti gat or a n d a ut h orize d site staff. At a mi n i m u m, 
dail y  mi ni m u m a n d ma xi m u m te m perat ures f or all site st ora ge l ocati o ns m ust be 
d oc u me nte d a n d a vaila ble u p o n re q uest. Data f or n o n w or ki n g da y s m ust i n dicate t he 
mi ni m u m a n d ma xi m u m te m perat ures si nce pre vi o usl y  d oc u me nte d u p o n ret ur n t o 
b usi ness.
4.
A n y  e xc ursi o ns fr o m t he st u d y i nter ve nti o n la bel st ora ge c o n diti o ns s h o ul d be re p orte d t o 
Pfizer u p o n disc o ver y  al o n g wit h acti o ns ta ke n. T he site s h o ul d acti vely p urs ue o pti o ns 
f or ret ur ni n g t he st u dy i nter ve nti o n t o la bele d st ora ge c o n diti o ns, as s o o n as p os si ble. 
O nce a n e xc ursi o n is i de ntifie d, t he st u d y i nter ve nti o n m ust be q uara nti ne d a n d n ot use d 
u ntil Pfizer pr o vi des per missi o n t o use t he st u d y  i nter ve nti o n. S pecific details re gar di n g 
t he e xc ursi o n defi niti o n a n d i nf or mati o n t o re p ort f or eac h e xc ursi o n will be pr o vi de d t o 
t he site i n t he IP M or ot her s pecifie d l ocati o n.
5.
A n y  st ora ge c o n diti o ns state d i n t he S R S D will be s u perse de d b y t he st ora ge c o n diti o ns 
state d o n t he la bel. Site staff will i nstr uct partici pa nts o n t he pr o per st ora ge re q uire me nts 
f or ta ke-h o me st u d y  i nter ve nti o n. See t he IP M f or st ora ge c o n diti o ns of t he st u d y  
i nter ve nti o n.
6.
St u d y  i nter ve nti o ns s h o ul d be st ore d i n t heir ori gi nal c o ntai ners.
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
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Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 54
6.4.1. Blinding of Participants
Participants and their caregivers will be blinded to their assigned study intervention.
6.4.2. Blinding of Site Personnel
Investigators and other site staff will be blinded to participants’ assigned study intervention. 
Participants will be assigned to receive study intervention according to the assigned treatment 
group from the randomization scheme. Investigators will remain blinded to each participant’s 
assigned study intervention until all participants complete the Day 35 visit (or early 
discontinuation prior to Day 35 visit). 
In the event of a Quality Assurance audit, the auditor(s) will be allowed access to unblinded 
study intervention records at the site(s) to verify that randomization/dispensing has been done 
accurately.
6.4.3. Blinding of the Sponsor
The study will be unblinded after all participants complete the Day 35 visit (or early 
discontinuation prior to Day 35 visit) and analyses through Day 35, including the primary 
and key secondary efficacy endpoint analyses, will be conducted. Details of the unblinded 
sponsor staff supporting the E-DMC and the timing of unblinding will be outlined in the 
Unblinding Plan. The majority of sponsor staff will be blinded to study intervention 
allocation. A third-party designee will be unblinded to limit the number of sponsor staff that 
need to be unblinded. Limited sponsor staff independent of the study team may be unblinded 
to support the interactions with, and the unblinded analyses for, the E-DMC and regulatory 
authorities that may be required while the study is ongoing. For the efficacy IAs, sponsor 
staff will only be unblinded at the group level and not have access to individual participant 
assignments. For the PK IA, participant-level unblinding will be restricted to limited sponsor 
staff performing the PK IA who will be independent from the study and have no other 
responsibilities associated with the study. 
6.4.4. Breaking the Blind 
The IRT will be programmed with blind-breaking instructions. In case of an emergency, the 
investigator has the sole responsibility for determining if unblinding of a participant’s 
treatment assignment is warranted. Participant safety must always be the first consideration 
in making such a determination. If the investigator decides that unblinding is warranted, the 
investigator should attempt to contact the study medical monitor prior to unblinding a 
participant’s treatment assignment unless this could delay further management of the 
participant. If a participant’s treatment assignment is unblinded, the sponsor must be notified 
within 24 hours after breaking the blind. The date and reason that the blind was broken must 
be recorded in the source documentation and CRF.
The study-specific IRT reference manual and IPM will provide the contact information and 
further details on the use of the IRT system.
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 5 5
6. 5. St u d y I nter ve nti o n C o m pli a nce
W he n partici pa nts self -a d mi nister st u d y i nter ve nti o n(s) at h o me, c o m plia nce wit h st u d y 
i nter ve nti o n will be assesse d at eac h visit as i n dicate d i n t he S o A . 
Partici pa nts will be iss ue d a pa per d osi n g l o g a n d will be trai ne d h o w t o re c or d t he date a n d 
ti me of st u d y i nter ve nti o n d osi n g o n Da y 1. T he partici pa nt will bri n g t he pa per d osi n g l o g t o 
eac h st u d y visit u ntil t he d osi n g l o g is c ollecte d after d osi n g is c o m plete.
Site pers o n nel will re vie w t he d osi n g l o g at site visits as i n dica te d i n t he S o A . If a ny 
n o nc o m plia nce wit h d osi n g e ntries is s us pecte d or o bser ve d i n t he data, site pers o n nel re mi n d 
t he partici pa nt of t he rele va nt st u d y pr oce d ures a n d/ or e nteri n g t he d osi n g i nf or mati o n i n t he 
d osi n g l o g, as a p plic a ble.
St u d y  i nter ve nti o n c o m plia nce a n d d ose a d mi nistrati o n dates a n d ti mes will be rec or de d i n 
t he C R F a n d will be assesse d b y  dele gate d st u d y pers o n nel at st u d y visits t hr o u g h c o u nti n g 
ret ur ne d ta blets, re vie wi n g t he d osi n g l o g, a n d disc ussi o n wit h t he partici pa nt, if a p plica ble. 
A rec or d of t he n u m ber of ta blets dis pe nse d t o a n d ta ke n b y  eac h partici pa nt m ust be 
mai ntai ne d a n d rec o ncile d wit h st u d y  i nter ve nti o n a n d c o m plia nce rec or ds as s o urce 
d oc u me ntati o n. De viati o n(s) fr o m t he prescri be d d osa ge re gi me n s h o ul d be rec or de d i n 
s o urce d oc u me nts. 
T he f oll o wi n g n o nc o m plia nce cases will be c o nsi dere d me dicati o n err ors a n d re p orte d as 
pr ot oc ol de viati o ns (see Secti o n 8. 4. 9 ):

Partici pa nts missi n g st u d y i nter ve nti o n f or 2 c o nsec uti ve d oses.

Partici pa nts w h o ha ve a n o verall st u d y  i nter ve nti o n c o m plia nce < 8 0 % or > 1 2 0 %.
6. 6. D ose M o dific ati o n 
D ose m o dificati o ns are n ot per mitte d i n t his st u d y .
6. 7. C o nti n ue d Access t o St u d y I nter ve nti o n After t he E n d of t he St u d y
N o st u d y  i nter ve nti o n will be pr o vi de d t o partici pa nts at t he e n d of t heir st u d y partici pati o n. 
It is e x pecte d t hat partici pa nts will be treate d as re q uire d wit h sta n dar d-of -care treat me nts, as 
a d vise d b y t hei r us ual care p h ysicia n.
6. 8. Tre at me nt of O ver d ose
F or t his st u d y , a n y si n gle d ose of sis u nat o vir greater t ha n  
m g or a dail y d ose greater t ha n 
m g wit hi n t he first 2 4 -h o ur ti me peri o d will be c o nsi dere d a n o ver d ose. T hese d oses 
were f o u n d t o be well -t olerate d, safe, a n d mai ntai ne d e x p os ures bel o w t he N O A E L i n 
pre vi o us cli nical st u dies.
T here is n o s pecific treat me nt f or a n o ver d ose. 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 5 6
I n t he e ve nt of a n o ver d ose, t he i n vesti gat or s h o ul d:
1.
C o ntact t he st u d y  me dical m o nit or wit hi n 2 4 h o urs.
2.
Cl osel y  m o nit or t he partici pa nt f or a n y A Es/ S A Es a n d la b orat or y  a b n or malities as 
me dicall y  a p pr o priate a n d f oll o w u p u ntil res ol uti o n, sta bilizati o n, t he e ve nt is ot her wise 
e x plai ne d, or t he partici pa nt is l ost t o f oll o w -u p (as defi ne d i n Secti o n 7. 3 ). 
3.
D oc u me nt t he q ua ntit y of t he e xcess d ose as well as t he d urati o n of t he o ver d ose i n t he 
C R F.
4.
O ver d ose is re p orta ble t o Pfizer Safet y  o nl y w he n ass oci ate d wit h a n S A E .
5.
O btai n a bl o o d sa m ple f or P K a nal ys is wit hi n 2 4 h o urs fr o m t he date of t he last d ose of 
st u d y i nter ve nti o n if re q ueste d b y t he st u d y me dical m o nit or ( deter mi ne d o n a 
case-b y -case basis).
Decisi o ns re gar di n g d ose i nterr u pti o ns or m o dificati o ns will be ma de b y  t he i n vesti gat or i n 
c o ns ultati o n wit h t he st u d y  me dical m o nit or as nee de d base d o n t he cli nical e val uati o n of t he 
partici pa nt.
6. 9. Pri or a n d C o nc o mit a nt T her a p y
Pr o hi bite d me dic ati o ns pri or t o t he st u d y:
Beca use t he p har mac ol o gical i n d ucti o n effect o n 
lasts f or a b o ut 1 4 da y s, a n y 
a d mi nistrati o n of a m o derate or str o n g 
i n d ucer m ust ha ve e n de d at least 1 4 da y s 
pri or t o ra n d o mizati o n.
Si milarl y , c o nsi deri n g t hat p har mac ol o gical i n hi biti o n of  
e nz yme w a nes 
a p pr o xi matel y 1 4 da ys after e x p os ure t o a n i n hi bit or, a n y m o derate or str o n g
i n hi bit or m ust ha ve bee n disc o nti n ue d at least 1 4 da ys bef ore ra n d o mizati o n ( 2 1 da ys f or 
St J o h n’s w ort).
A d diti o nall y , a d mi nistrati o n of
m ust ha ve e n de d 5 da y s pri or t o 
ra n d o mizati o n a n d a d mi nistrati o n of
m ust ha ve e n de d at least 1 2 h o urs pri or t o 
ra n d o mizati o n.
A n o n -e x ha usti ve list of pr o hi bite d me dicati o ns is i ncl u de d i n Secti o n 1 0. 9 .
Pr o hi bite d me dic ati o ns d uri n g t he st u d y:
Use of a n y c o nc o mita nt me dicati o n t hat is eit her a str o n g or m o derate i n d ucer, or a str o n g or 
m o derate i n hi bit or of 
e nz yme, a n d t heref ore ma y  res ult i n altere d e x p os ure of 
sis u nat o vir, is pr o hi bite d d uri n g t he d osi n g peri o d of t he st u d y. 
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI
C CI
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7. DISCONTINUATION OF STUDY INTERVENTION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL
7.1. Discontinuation of Study Intervention
It may be necessary for a participant to permanently discontinue study intervention. Reasons 
where study intervention will be permanently discontinued include the following: 
!
AE of Grade 3 severity or greater and considered by the investigator to be related to 
the study intervention;
!
SAE considered by the investigator to be related to the study intervention;
!
Requirement for prohibited concomitant medication;
!
Participant who becomes pregnant during the course of the study;
!
Study terminated by the Sponsor;
!
Withdrawal by participant or legally authorized representative;
!
If post-screening eGFR falls to <30 mL/min/1.73 m2 the participant will be instructed 
to discontinue any remaining study intervention doses as soon as study staff become 
aware of the eGFR results.
!
If the participant is hospitalized, and none of the criteria above are met, study 
intervention may continue to be administered, as feasible, and based on the judgment 
of the investigator.
Discontinuation of study intervention does not represent withdrawal from the study. If study 
intervention is permanently discontinued, the participant should remain in the study to be 
evaluated for all subsequent planned assessments. See the SoA for data to be collected at the 
time of discontinuation of study intervention and follow-up for any further evaluations that 
need to be completed.
In the event of discontinuation of study intervention, it must be documented on the 
appropriate CRF/in the medical records whether the participant is discontinuing further 
receipt of study intervention or also from study procedures, further study follow-up, and/or 
future collection of additional information.
7.1.1. Potential Cases of Acute Kidney Injury
Participants exposed to IMP demonstrating transient or sustained increase in Screat (with 
decrease in Screat-based eGFR) requiring expedited evaluation to differentiate AKI from 
DICI. DICI is defined as transporter-mediated effect related to altered renal tubular creatinine 
handling without histological injury. 
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AKI may be due to one or more types of injury, including DIKI. Differentiation of DIKI 
from other causes of AKI and from DICI may require clinical, radiographic, histopathologic, 
and laboratory assessments, as well as nephrology consultation.
Follow-up Assessments
The participant should return to the site for evaluation as soon as possible, preferably within 
48 hours of awareness of the abnormal results.
Evaluation should include physical examination, laboratory tests, detailed medical and 
surgical history, review of all medications (including recreational drugs and supplements 
[herbal]), family history, sexual history, travel history, blood transfusion, and potential 
occupational exposure to chemicals.
Laboratory assessments should include simultaneous serum cystatin C (Scys) and serum 
creatinine (Screat) tests. Estimates of eGFR and Screat-based eGFR and combined Screat-
Scys-based eGFR should also be derived using the appropriate equation described in 
Appendix 7 in Section 10.7.
If appropriate, nephrology consultation may be recommended to facilitate differentiation of 
renal parenchymal disease, pre-renal azotemia, and post-renal obstruction.
Differentiating Acute Kidney Injury from DICI:
A confirmed Screat increase is defined as:
(i) ≥0.3 mg/dL (≥26.5 μmol/L) within prior 48 hours OR 
(ii) confirmed Screat increase ≥1.5 times baseline (known or suspected to have 
occurred within the prior 7 days). 
Based on the assessments performed, suspected AKI (including DIKI) may be differentiated 
from DICI as follows.
Adult Participants
AKI (including DIKI)
Any one of the below
DICI
Scys & Screat
Simultaneous, confirmed serum cystatin 
C (Scys) increase and confirmed Screat 
increase 
Confirmed Screat increase without 
confirmed increase in reflex Scys 
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AKI (including DIKI)
Any one of the below
DICI
eGFR
Decrease in Screat-based eGFR and 
combined Screat-Scys-based eGFR (when 
available)
AND 
Confirmed Screat-based eGFR 
decrease without confirmed combined 
Screat-Scys-based eGFR decrease.
Albuminuria or 
proteinuria
Confirmed albuminuria increase (see 
Appendix 7 in Section 10.7) for Grades 
A1 to A3 quantitation)
Urine volume
Urine volume <0.5 mL/kg/h for 6 
consecutive hours
Regardless of the presence or absence of increase in Screat, DIKI and other causes of AKI 
may be suspected if new-onset or worsening albuminuria or proteinuria are detected.
All confirmed cases of clinically relevant decrease in kidney function should be considered 
potential cases of DIKI if no other reason for the kidney function abnormalities has been 
found.
7.1.2. Liver Injury 
A participant who meets the criteria of potential DILI (Hy’s law) case as described in 
Section 10.6 will be withdrawn from study intervention. 
7.1.3. ECG Changes
A participant who meets either bulleted criterion based on ECG readings will be withdrawn 
from the study intervention. 
!
QTcF >500 ms.
!
Change from baseline: QTcF ≥60 ms.
If a clinically significant finding is identified (including, but not limited to, changes from 
baseline in QTcF after enrollment), the investigator or qualified designee will determine if 
the participant can continue in the study and if any change in participant management is 
needed. This review of the ECG printed at the time of collection must be documented. Any 
new clinically relevant finding should be reported as an AE.
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7.1.4. Pregnancy
If a participant becomes aware of pregnancy during the study, they are to be discontinued 
from study intervention.
7.1.5. COVID-19 (SARS-CoV-2) and influenza
Participants will be tested for SARS-CoV-2 and influenza within 7 days of study 
randomization. If a participant develops an infection from influenza or SARS-CoV-2 through 
the course of the study, the investigator will decide whether to continue or permanently 
discontinue treatment with the study drug. If the patient’s treatment requires a prohibited 
medication (eg, nirmatrelvir/ritonavir), the study drug must be discontinued. If a participant 
has SARS-CoV-2 or influenza during the study, this should be reported as an AE or SAE (as 
appropriate).
7.1.6. Temporary Discontinuation 
Not permitted.
7.1.7. Rechallenge 
Not permitted.
7.2. Participant Discontinuation/Withdrawal From the Study 
A participant may withdraw from the study at any time at their own request. Reasons for 
discontinuation from the study include the following:
!
Refused further study procedures;
!
Lost to follow up;
!
Study terminated by Sponsor;
!
Withdrawal of consent by authorized legal representative.
At the time of discontinuing from the study, if possible, an early discontinuation visit should 
be conducted. See the SoA for assessments to be collected at the time of study 
discontinuation and follow-up and for any further evaluations that need to be completed.
If a participant withdraws from the study, they may request destruction of any remaining 
samples taken and not tested, and the investigator must document any such requests in the 
site study records and notify the sponsor accordingly.
If the participant withdraws from the study and also withdraws consent (see Section 7.2.1) 
for disclosure of future information, no further evaluations will be performed and no 
additional data will be collected. The sponsor may retain and continue to use any data 
collected before such withdrawal of consent.
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7.2.1. Withdrawal of Consent 
Participants who request to discontinue receipt of study intervention will remain in the study 
and must continue to be followed for protocol-specified follow-up procedures. The only 
exception to this is when a participant specifically withdraws consent for any further contact 
with them or persons previously authorized by the participant to provide this information. 
Participants should notify the investigator in writing of the decision to withdraw consent 
from future follow-up, whenever possible. The withdrawal of consent should be explained in 
detail in the medical records by the investigator, as to whether the withdrawal is only from 
further receipt of study intervention or also from study procedures and/or posttreatment study 
follow-up, and entered on the appropriate CRF page. In the event that vital status (whether 
the participant is alive or dead) is being measured, publicly available information should be 
used to determine vital status only as appropriately directed in accordance with local law.
7.3. Lost to Follow-Up 
A participant will be considered lost to follow-up if the participant repeatedly fails to return 
for scheduled visits and is unable to be contacted by the study site.
The following actions must be taken if a participant fails to attend a required study visit:
!
The site must attempt to contact the participant and reschedule the missed visit as 
soon as possible. Counsel the participant on the importance of maintaining the 
assigned visit schedule, and ascertain whether the participant wishes to and/or should 
continue in the study;
!
Before a participant is deemed lost to follow-up, the investigator or designee must 
make every effort to regain contact with the participant (where possible, 3 telephone 
calls and, if necessary, a certified letter to the participant’s last known mailing 
address or local equivalent methods). These contact attempts should be documented 
in the participant’s medical record;
!
Should the participant continue to be unreachable, the participant will be considered 
to have withdrawn from the study. 
8. STUDY ASSESSMENTS AND PROCEDURES
8.1. Administrative and Baseline Procedures
The investigator (or an appropriate delegate at the investigator site) must obtain a signed and 
dated ICD before performing any study-specific procedures.
Study procedures and their timing are summarized in the SoA. Protocol waivers or 
exemptions are not allowed.
Adherence to the study design requirements, including those specified in the SoA, is essential 
and required for study conduct.
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 6 3
All scree ni n g e val uati o ns m ust be c o m plete d a n d re vie we d t o c o nfir m t hat p ote ntial 
partici pa nts meet all eli gi bilit y  criteria. T he i n vesti gat or will mai ntai n a scree ni n g l o g t o 
rec or d details of all partici pa nts scree ne d a n d t o c onfir m eli gi bilit y  or rec or d reas o ns f or 
scree ni n g fail ure, as a p plica ble.
E ver y ef f ort s h o ul d be ma de t o e ns ure t hat pr ot oc ol-re q uire d tests a n d pr oce d ures are 
c o m plete d as descri be d. H o we ver, it is a ntici pate d t hat fr o m ti me t o ti me t here ma y be 
circ u mstances o utsi de t he c o ntr ol of t he i n vesti gat or t hat ma ke it u nfeasi ble t o perf or m t he 
test. In t hese cases, t he i n vesti gat or m ust ta ke all ste ps necessar y  t o e ns ure t he safety a n d 
well bei n g of t he partici pa nt. W he n a pr ot oc ol -re q uire d test ca n n ot be perf or med, t he 
i n vesti gat or will d oc u me nt t he reas o n f or t he misse d test a n d a ny c orrecti ve a n d pre ve nti ve 
acti o ns t hat t he y ha ve ta ke n t o e ns ure t hat re q uire d pr ocesses are a d here d t o as s o o n as 
p ossi ble. T he st u d y  tea m m ust be i nf or me d of t hese i nci de nts i n a timel y  ma n ner.
F or sa m ples bei n g c ollecte d a n d s hi p pe d, detaile d c ollecti o n, pr ocessi n g, st ora ge, a n d 
s hi p me nt i nstr ucti o ns a n d c o ntact i nf or mati o n will be pr o vi de d t o t he i n vesti gat or site pri or 
t o i nitiati o n of t he st u d y.
T he mi ni m u m t otal bl o o d sa m pli n g v ol u me f or i n di vi d ual partici pa nts i n t his st u d y  is 
a p pr o xi matel y 7 0 m L a n d 9 0 m L f or t he a p pr o xi matel y
partici pa nts pr o vi di n g a d diti o nal 
P K sa m ples. A d diti o nal bl o o d sa m ples ma y be ta ke n f or safet y or eli gi bilit y assess me nts at 
ti mes s pecifie d i n t he S o A , pr o vi de d t he t otal v ol u me ta ke n d uri n g t he st u d y d oes n ot e xcee d 
5 5 0 m L  d uri n g a ny peri o d of 5 6 c o nsec uti ve da ys. 
Partici pa nts m ust ha ve a p ositi ve R S V test bef ore e nr oll me nt i nt o t he cli nical st u d y . R S V, 
S A R S -C o V -2, a n d i nfl ue nza dia g n ostic tests or ot her pr oce d ures c o n d ucte d as part of t he 
partici pa nt’s sta n dar d of care a n d o btai ne d bef ore si g ni n g of t he I C D ma y  be utilize d f or 
eli gi bilit y re vie w p ur p oses pr o vi de d t he pr oce d ures met t he pr ot oc ol-s pecifie d criteria a n d 
were pe rf or me d wit hi n t he ti me fra me defi ne d i n t he S o A . If a partici pa nt d oes n ot ha ve 
access t o o btai n a n R S V test, please see Secti o n 5. 4 f or t he pre-scree ni n g pr oce d ure i nf or me d 
c o nse nt o pti o n. 
Partici pa nts i n t he U nite d States will be i n vite d t o pr o vi de i nf or me d c o nse nt t o partici pate i n 
o pti o nal, a d diti o nal researc h usi n g real w orl d data t o descri b e l o n g-ter m healt h o utc o mes a n d 
healt hcare utilizati o n (see Secti o n 1 0. 1 0. 1 )
8. 1. 1. B aseli ne Pr oce d ures 
Me dical hist or y  i n a d diti o n t o R S V disease hist or y a n d de m o gra p hics will be c ollecte d at 
scree ni n g. S m o ki n g stat us will be c ollecte d. 
C o m plete me dicati o n hist or y  of all prescri pti o n or n o n prescri pti o n dr u gs (i ncl u di n g 
vacci nati o ns), a n d dietar y a n d her bal s u p ple me nts ta ke n wit hi n 3 0 da ys pri or t o t he pla n ne d 
first d ose will be c ollecte d. R S V-relate d vacci nati o ns a n d m o n ocl o nal a nti b o d y f or t he 
treat me nt or pre ve nti o n of R S V at a n y ti me pri or t o ra n d o mizati o n will als o be c ollecte d. 
Me dicati o ns ca usi n g o n g o i n g i m m u n os u p pressa nt effect, s uc h as bi ol o gics or ca ncer 
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treatments, administered at any time prior to randomization will be collected. Risk factors for 
the participant developing severe RSV illness will be recorded.
Viral Screening Assessment for Study Eligibility
If the participant fails to provide a negative test for SARS-CoV-2 and influenza within 7 days 
of randomization, a specimen will be collected at screening for viral testing of SARS-CoV-2 
and/or influenza. Viral testing of SARS-CoV-2 and/or influenza will be performed according 
to the manufacturer information for use Some testing equipment will simultaneously test this 
nasal swab for RSV, and a negative RSV result from this test will exclude the participant 
from the study.
8.1.2. Telehealth Visits 
Telehealth visits may be used to assess participant safety and collect data points. Telehealth 
includes the exchange of healthcare information and services via telecommunication 
technologies (eg, audio, video, videoconferencing software) remotely, allowing the 
participant and the investigator to communicate on aspects of clinical care, including medical 
advice, reminders, education, and safety monitoring. Assessments that may be performed 
during a telehealth visit are described in the SoA.
Study participants must be reminded to promptly notify site staff about any change in their 
health status.
8.2. Efficacy Assessments
8.2.1. RSV-related hospitalizations and Medical Details
Details of participants’ RSV-related medical visits (ie, hospitalization of any duration, urgent 
care, emergency room) will be collected during study visits, including level of care (ICU 
status), dates of utilization (including admission and discharge), and discharge status, as 
applicable. 
For the primary endpoint, hospitalization of at least 24 hours of acute care is defined as ≥24 
hours of acute care in a hospital or similar acute care facility. This includes specialized acute 
medical care unit within an assisted living facility or nursing home. Participants who are 
waiting in an emergency department or other hospital unit for an inpatient bed to become 
available are considered hospitalized provided that a decision to admit to inpatient care has 
occurred. For the secondary endpoint of RSV-related visits (urgent care/ED/hospital) or 
death from any cause, no minimum duration of hospitalization is required.
Investigators will determine if a medical visit is related to RSV. For reference, RSV related 
medical visits are those attendances that would not otherwise occur in the absence of the 
RSV infection. These may include visits for: deterioration or decompensation of the lung 
function that require supplemental oxygen; development of secondary respiratory tract 
infections that require antibiotic treatment; management of severe symptoms associated with 
RSV such as fever; worsening or decompensation of cardiac or renal function in patients with 
underlying cardiac or renal disease.
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8.2.2. Survival status
Information about the death of a participant may be collected from death registries, hospital 
databases, other healthcare professionals, from participant’s legal representatives, or other 
persons authorized by the participant and according to local regulations. The death of a 
participant cannot be assumed by their non-responsiveness, as the participant may be lost to 
follow-up.
8.2.3. Clinical response 
Clinical response is evaluated by the investigator at Day 5, 10, 15, and 28 visits using the 
criteria for ARI in Table 2 that were required for study entry.
Table 2.
Criteria for ARI
ARI is defined as the presence of 1 or more of the following signs and symptoms:
!
New or increased nasal congestion.
!
New or increased nasal discharge.
!
New or increased sore throat.
!
New or increased cough.
!
New or increased sputum production.
!
New or increased shortness of breath.
!
New or increased wheezing.
The outcome of this assessment will be recorded in the CRF as one of the following 
categories:
!
Resolution – All ARI signs or symptoms are absent or have returned to pre-infection 
status.
!
Improvement – No new ARI signs or symptoms, and no worsening of existing signs 
or symptoms compared to the Day 1 visit. At least one sign or symptom (but not all) 
present at Day 1 is absent, improved or has returned to pre-infection status.
!
No change – No change in the ARI signs or symptoms compared to the Day 1 visit.
!
Worsening – New or worsening in severity of at least one ARI signs or symptom 
compared to the Day 1 visit.
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8.2.4. RSV-related lower respiratory tract infection
Signs and symptoms of RSV will be collected by the Investigator per the SoA (Section 1.3) 
during scheduled visits. Criteria for diagnosis of LRTI are provided in Table 3. Criteria for 
diagnosis of severe LRTI (sLRTI) are provided in Table 4 [14]. Intensity grading displayed 
in Table 5 is a component of the severe LRTI criteria. An episode of LRTI that does not meet 
criteria for sLRTI is considered non-severe LRTI (nsLRTI). Investigators will determine if 
sLRTI or nsLRTI is related to RSV (referred to as sLRTI-RSV and nsLRTI-RSV).
!
Development of LRTI is defined as transitioning from not having LRTI at 
randomization to having nsLRTI-RSV or sLRTI-RSV.
!
Progression of LRTI is defined as development of LRTI or transitioning from 
nsLRTI-RSV at randomization to sLRTI-RSV.
!
Resolution of LRTI is defined as transition from nsLRTI-RSV or sLRTI-RSV at 
randomization to not having nsLRTI-RSV and not having sLRTI-RSV.
!
Improvement in LRTI status is defined as LRTI resolution or transition from sLRTI-
RSV at randomization to nsLRTI-RSV.
Table 3.
Criteria for LRTI
LRTI is defined as:
!
≥2 lower respiratory signs or symptoms for at least 24 hours including at least 1 lower 
respiratory sign;
Or 
!
3 lower respiratory symptoms for at least 24 hours.
Lower respiratory symptoms
!
New or increased sputum.
!
New or increased cough.
!
New or increased dyspnea (shortness of 
breath).
Lower respiratory signs
!
New or increased wheezing.
!
New or increased crackles/ronchi based 
on chest auscultation.
!
Respiratory rate ≥ 20 respirations/ 
minute.
!
Low or decreased oxygen saturation (O2
< 95% or ≤ 90% if pre-season baseline is 
< 95%).
!
Need for new or increased oxygen 
supplementation.
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Table 3.
Criteria for LRTI
LRTI is defined as:
!
≥2 lower respiratory signs or symptoms for at least 24 hours including at least 1 lower 
respiratory sign;
Or 
!
3 lower respiratory symptoms for at least 24 hours.
Criteria for LRTI are based on Papi, et al. 2023 [14].
Table 4.
Criteria for severe LRTI
Severe LRTI is defined as the presence of LRTI with at least one of the following 
criteria:
!
≥2 lower respiratory signs.
!
An LRTI episode assessed as ‘severe intensity’ by investigator per intensity grading in 
Table 5.
!
Need for hospitalization.
!
Need for positive airway pressure therapy (eg, CPAP).
!
Need for other types of mechanical ventilation.
Lower respiratory signs:
!
New or increased wheezing.
!
New or increased crackles/ronchi based on chest auscultation.
!
Respiratory rate ≥ 20 respirations/minute.
!
Low or decreased oxygen saturation (O2 < 95% or ≤90% if pre-season baseline is 
<95%).
!
Need for new or increased oxygen supplementation.
Criteria for severe LRTI are based on Papi, et al. 2023[14].
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Table 5.
Intensity grading for LRTI 
Mild 
intensity
An LRTI episode which is easily tolerated by the participant causing minimal 
discomfort and not interfering with everyday activities* or self-care**.
Moderate 
intensity
An LRTI episode which is sufficiently discomforting to interfere with 
everyday activities* but does not interfere with self-care**.
Severe 
intensity
An LTRI episode which prevents everyday activities* and interferes with 
self-care.**
Intensity grading for LRTI are based on Papi, et al. 2023 [14].
* Everyday activities include housework, work, family activities, or leisure activities. Interference in 
everyday activities must be due to signs and symptoms of the acute respiratory infection and note solely due 
to viral infection quarantining/isolation considerations. 
**Self-care includes feeding, bathing, grooming, dressing, and toileting.
Change of everyday activities and self-care should be compared to each patient’s baseline status. For 
example, a previously mobile participant becoming bed bound would be an example of severe LRTI.
8.2.5. Post-treatment ARI
Participants must meet criteria for ARI (as defined in Table 2 to be enrolled in the study. Any 
patient with a clinical response of Resolution (see Section 8.2.3) at Day 5, 10, or 15 that later 
experiences new or worsening of ARI symptoms lasting more than 1 day should contact the 
site staff or investigator to schedule an unplanned post-treatment ARI visit, which should 
optimally occur within 2 days after the onset of new or worsening symptoms. If the 
participant is scheduled to have a planned treatment visit or follow-up visit within 3 days of 
symptom onset of the recurrent ARI, then an unplanned study visit is not necessary.
The purpose of this visit is to perform a clinical assessment and collect a NP swab for 
virology assessment that can be used to evaluate potential recurrence of RSV infection. 
8.2.6. Oxygen Support Details
Type of oxygen support (eg, oxygen supplementation received, mechanical ventilation or 
ECMO received in hospital) will be collected at baseline and subsequent visits.
8.2.7. Imaging Assessments 
Unplanned imaging performed according to routine medical care will be recorded in the 
source document.
8.2.8. PRO Assessment
8.2.8.1. EQ-5D-5L
EQ-5D is a standardized, validated, generic health related quality of life questionnaire used 
in clinical and economic HTA evaluations. The questionnaire comprises five questions and 
covers dimensions of mobility, self-care, usual activities, pain/discomfort, and 
anxiety/depression. Designed to be self-completed by respondents, the instrument takes a few 
minutes to complete and is intended to be cognitively undemanding [15-20].
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The participant will be invited to complete the questionnaire on an electronic device at the 
site, and according to the SoA. The first questionnaire should be administered before taking 
the study drug. If assistance is required to help complete the questionnaire, the site staff 
should remain neutral and avoid leading participants towards specific answers. 
In the suite of EQ-5D instruments developed, the most recent EQ-5D-5L has expanded to a 
5-level scale of evaluation compared to the original 3 level evaluation scale. Validation has 
shown improved reliability and sensitivity of the EQ-5D-5L compared with the original in 
various diseases. The instrument retains utilities in assessing mobility, self-care, usual 
activities, pain/discomfort, anxiety/depression and health status using a VAS. The EQ-5D-5L 
should be completed as described in the SoA, with appropriate training to ensure appropriate 
measurement at baseline and to limit any potential influence on patient self-assessment 
during denoted site visits [15-20].
8.2.9. Household Characteristics
Household characteristics will be determined through interview with the participant and may 
be updated during the study. This assessment is exploratory in nature and will support the 
characterization of household transmission of acute respiratory infection. The household 
characteristics include:
!
Number of people living in the household.
!
Number of additional cases of confirmed or suspected acute respiratory infection 
among household contacts.
!
Number of additional confirmed RSV positive household contacts.
8.3. Safety Assessments
Planned time points for all safety assessments are provided in the SoA. Unscheduled safety 
measurements may be obtained at any time during the study to assess any perceived safety 
issues.
8.3.1. Physical Examinations
A general physical examination will be performed by a medically qualified individual (or 
other authorized delegate) at screening/baseline (see Table 1) and include, at a minimum, 
assessments of the cardiovascular, respiratory, gastrointestinal, and neurological systems. 
Height and weight will also be measured and recorded. Physical examinations conducted at 
subsequent study visits will be done at discretion of the investigator if the participant has 
symptoms that need to be evaluated. Investigators should pay special attention to any 
previously identified or new AE/targeted condition that the participant has experienced.
Physical examination findings collected during the study will be considered source record 
and will not be required to be reported, unless otherwise noted. Any untoward physical 
examination findings that are identified during the active collection period and meet the 
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definition of an AE or SAE (Appendix 3) must be reported according to the processes in 
Section 8.4.1 to Section 8.4.3.
8.3.2. Vital Signs
Temperature, pulse rate, respiratory rate, oxygen saturation level, and blood pressure will be 
assessed as specified in Table 1.
Any untoward vital sign findings that are identified during the active collection period and 
meet the definition of an AE or SAE (Appendix 3 in Section 10.3) must be reported 
according to the processes in Sections 8.4.1 to 8.4.3.
8.3.2.1. Blood Pressure and Pulse Rate
BP and PR measurements will be assessed with the participant, in the supine or seated 
position with their feet on the floor, when possible, with a completely automated device. 
Manual techniques will be used only if an automated device is not available.
BP and PR measurements should be preceded by at least 5 minutes of rest with the 
participant in a semisupine or sitting position, in a quiet setting without distractions.
BP and PR will be taken before blood collection for laboratory tests and consist of a single 
measurement of PR and 3 BP measurements (3 consecutive BP readings will be recorded at 
intervals of at least 1 minute apart). The average of the 3 BP readings will be recorded on the 
CRF.
8.3.2.2. Temperature and Respiratory Rate
Temperature (oral, tympanic, axillary, or temporal artery), and respiratory rate, will be 
assessed and recorded in the CRF.
8.3.2.3. Oxygen Saturation
Oxygen saturation will be assessed as part of the vital signs assessment by a pulse oximeter 
and recorded in the CRF. Participants who are on chronic oxygen supplementation will be 
assessed whilst on supplementation.
8.3.3. Electrocardiograms
A single, standard 12-lead ECG will be collected at times specified in the SoA section of this 
protocol using an ECG system that automatically calculates the HR and measures PR, QT, 
QTcF, and QRS intervals. The ECG should be performed after the participant has rested 
quietly for at least 5 minutes in a supine position. 
A qualified medical provider should interpret the 12-Lead ECG used for screening prior to 
enrollment.
ECG data will be submitted to a central laboratory for measurement and interpretation. The 
final ECG report from the central laboratory should be maintained in the participant’s source 
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documentation and be the final interpretation of the ECG recording. Any clinically 
significant changes from the baseline/Day 1 ECG may potentially be AEs (Appendix 8 in 
Section 10.8) and should be evaluated further, as clinically warranted. 
In some cases, it may be appropriate to repeat abnormal ECGs to rule out improper lead 
placement as contributing to the ECG abnormality. It is important that leads be placed in the 
same positions each time in order to achieve precise ECG recordings. If a machine-read QTc 
value is prolonged, as defined above, repeat measurements may not be necessary if a 
qualified medical provider’s interpretation determines that the QTcF values are in the 
acceptable range.
ECG values of potential clinical concern are listed in Appendix 8 in Section 10.8.
8.3.3.1. Alternative Facilities for Electrocardiograms 
The participant may visit an alternative facility to have the ECGs performed. Qualified study 
site personnel must order, receive, and review results. ECGs can also be performed through 
remote device collection.
8.3.4. Clinical Safety Laboratory Assessments 
See Appendix 2 (Section 10.2) for the list of clinical safety laboratory tests to be performed 
and the SoA for the timing and frequency. All protocol-required laboratory assessments, as 
defined in Appendix 2 (Section 10.2), must be conducted in accordance with the laboratory 
manual and the SoA. Unscheduled clinical laboratory measurements may be obtained at any 
time during the study to assess any perceived safety issues.
Laboratory safety parameters will be graded according to the DAIDS Table for Grading the 
Severity of Adult and Pediatric Adverse Events, version 2.1 [21]. The investigator must 
review the laboratory report, document this review, and record any clinically significant 
changes occurring during the study in the AE section of the CRF. Clinically significant 
abnormal laboratory test findings are those that are not associated with the underlying 
disease, unless judged by the investigator to be more severe than expected for the 
participant's condition.
All laboratory tests with values considered clinically significant and abnormal during 
participation in the study or within 28 days of the last dose administration after the last dose 
of study intervention should be repeated until the values return to normal or baseline or are 
no longer considered clinically significant by the investigator or study medical monitor.
If such values do not return to normal/baseline within a period of time judged reasonable by 
the investigator, the etiology should be identified and the sponsor notified.
See Appendix 6 (Section 10.6) for suggested actions and follow-up assessments in the event 
of potential DILI.
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See Appendix 7 (Section 10.7) for instructions for laboratory testing to monitor kidney 
function and reporting laboratory test abnormalities.
8.3.4.1. Alternative Facilities for Clinical Safety Laboratory Assessment 
Protocol-specified safety laboratory evaluations may be conducted at a local laboratory, 
during a mobile visit, or at home if permitted by local regulations. The local laboratory may 
be a standalone institution or within a hospital. The following safety laboratory evaluations 
may be performed at a local laboratory:
!
Hematology
!
Biochemistry 
If a local laboratory is used, qualified study site personnel must order, receive, and review 
results. Site staff must collect the local laboratory reference ranges and certifications/
accreditations for filing at the site. Laboratory test results are to be provided to the site staff 
as soon as possible. The local laboratory reports should be filed in the participant’s source 
documents/medical records. Relevant data from the local laboratory report should 
be recorded on the CRF.
8.3.5. Pregnancy Testing 
A urine or serum pregnancy test is required at screening. Following screening, pregnancy 
tests may be urine or serum tests, and must have a sensitivity of at least 25 mIU/mL. 
Pregnancy tests will be performed in WOCBP at the times listed in the SoA. 
8.4. Adverse Events, Serious Adverse Events, and Other Safety Reporting
The definitions of an AE and an SAE can be found in Appendix 3 in Section 10.3.
AEs may arise from symptoms or other complaints reported to the investigator by the 
participant (or, when appropriate, by a caregiver, surrogate, or the participant's legally 
authorized representative), or they may arise from clinical findings of the investigator or 
other healthcare providers (clinical signs, test results, etc).
The investigator and any qualified designees are responsible for detecting, documenting, and 
recording events that meet the definition of an AE or SAE and remain responsible to pursue 
and obtain adequate information both to determine the outcome and to assess whether the 
event meets the criteria for classification as an SAE or caused the participant to discontinue 
the study intervention (see Section 7.1). 
During the active collection period as described in Section 8.3, each participant/legal 
guardian/legally authorized representative will be questioned about the occurrence of AEs in 
a nonleading manner.
In addition, the investigator may be requested by Pfizer Safety to obtain specific follow-up 
information in an expedited fashion.
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8.4.1. Time Period and Frequency for Collecting AE and SAE Information
The time period for actively eliciting and collecting AEs and SAEs (“active collection 
period”) for each participant begins from the time the participant provides informed consent 
(including the pre-screening informed consent document, if applicable), which is obtained 
before undergoing any study-related procedure and/or receiving study intervention, through 
Day 35.
Follow-up by the investigator continues throughout the active collection period and until the 
AE or SAE or its sequelae resolve or stabilize at a level acceptable to the investigator.
When a clinically important AE remains ongoing at the end of the active collection period, 
follow-up by the investigator continues until the AE or SAE or its sequelae resolve or 
stabilize at a level acceptable to the investigator and Pfizer concurs with that assessment.
For participants who are screen failures, the active collection period ends when screen failure 
status is determined. For participants who provide pre-screening informed consent, the active 
collection period ends 30 minutes after collection of the pre-screening viral testing or once 
viral testing results become available, whichever occurs first. 
If the participant withdraws from the study and also withdraws consent for the collection of 
future information, the active collection period ends when consent is withdrawn.
If a participant permanently discontinues or temporarily discontinues study intervention 
because of an AE or SAE, the AE or SAE must be recorded on the CRF and the SAE 
reported using the CT SAE Report Form. 
Investigators are not obligated to actively seek information on AEs or SAEs after the 
participant has concluded study participation. However, if the investigator learns of any SAE, 
including a death, at any time after a participant has concluded study participation, and they 
consider the event to be reasonably related to the study intervention, the investigator must 
promptly report the SAE to Pfizer using the CT SAE Report Form. 
8.4.1.1. Reporting SAEs to Pfizer Safety
All SAEs occurring in a participant during the active collection period as described in
Section 8.4.1 are reported to Pfizer Safety on the CT AE Report Form immediately upon 
awareness and under no circumstance should this exceed 24 hours, as indicated in 
Appendix 3 in Section 10.3. The investigator will submit any updated SAE data to the 
sponsor within 24 hours of its being available.
8.4.1.2. Recording Nonserious AEs and SAEs on the CRF
All nonserious AEs and SAEs occurring in a participant during the active collection period, 
which begins after obtaining informed consent as described in Section 8.4.1, will be recorded 
on the AE section of the CRF.
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The investigator is to record on the CRF all directly observed, and all spontaneously reported 
AEs and SAEs reported by the participant.
As part of ongoing safety reviews conducted by the sponsor, any nonserious AE that is 
determined by the sponsor to be serious will be reported by the sponsor as an SAE. To assist 
in the determination of case seriousness, further information may be requested from the 
investigator to provide clarity and understanding of the event in the context of the clinical 
study.
8.4.2. Method of Detecting AEs and SAEs
The method of recording, evaluating, and assessing causality of AEs and SAEs and the 
procedures for completing and transmitting SAE reports are provided in Appendix 3 in 
Section 10.3.
Care will be taken not to introduce bias when detecting AEs and/or SAEs. Open-ended and 
nonleading verbal questioning of the participant is the preferred method to inquire about 
AE occurrences.
8.4.3. Follow-Up of AEs and SAEs
After the initial AE or SAE report, the investigator is required to proactively follow each 
participant at subsequent visits/contacts. For each event, the investigator must pursue and 
obtain adequate information until resolution, stabilization, the event is otherwise explained, 
or the participant is lost to follow-up (as defined in Section 7.3).
In general, follow-up information will include a description of the event in sufficient detail to 
allow for a complete medical assessment of the case and independent determination of 
possible causality. Any information relevant to the event, such as concomitant medications 
and illnesses, must be provided. In the case of a participant death, a summary of available 
autopsy findings must be submitted as soon as possible to Pfizer Safety. 
Further information on follow-up procedures is provided in Appendix 3 (Section 10.3).
8.4.4. Regulatory Reporting Requirements for SAEs
Prompt notification by the investigator to the sponsor of an SAE is essential so that legal 
obligations and ethical responsibilities toward the safety of participants and the safety of a 
study intervention under clinical investigation are met.
The sponsor has a legal responsibility to notify both the local regulatory authority and other 
regulatory agencies about the safety of a study intervention under clinical investigation. The 
sponsor will comply with country-specific regulatory requirements relating to safety 
reporting to the regulatory authority, IRBs/ECs, and investigators.
Investigator safety reports must be prepared for SUSARs according to local regulatory 
requirements and sponsor policy and forwarded to investigators as necessary.
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An investigator who receives SUSARs or other specific safety information (eg, summary or 
listing of SAEs) from the sponsor will review and then file it along with the SRSD(s) for the 
study and will notify the IRB/EC, if appropriate according to local requirements.
8.4.5. Environmental Exposure, Exposure During Pregnancy or Breastfeeding, and 
Occupational Exposure
Environmental exposure occurs when a person not enrolled in the study as a participant 
receives unplanned direct contact with or exposure to the study intervention. Such exposure 
may or may not lead to the occurrence of an AE or SAE. Persons at risk for environmental 
exposure include healthcare providers, family members, and others who may be exposed. An 
environmental exposure may include EDP, EDB, and occupational exposure.
Any such exposures to the study intervention under study are reportable to Pfizer Safety 
within 24 hours of investigator awareness.
8.4.5.1. Exposure During Pregnancy
An EDP occurs if:
!
A female participant is found to be pregnant while receiving or after discontinuing 
study intervention. 
!
A male participant who is receiving or has discontinued study intervention 
inseminates a female partner. 
!
A female nonparticipant is found to be pregnant while being exposed or having been 
exposed to study intervention because of environmental exposure. Below are 
examples of environmental EDP:
!
A female family member or healthcare provider reports that she is pregnant after 
having been exposed to the study intervention by ingestion.
!
A male family member or healthcare provider who has been exposed to the study 
intervention by ingestion then inseminates his female partner prior to or around the 
time of conception.
The investigator must report EDP to Pfizer Safety within 24 hours of the investigator’s 
awareness, irrespective of whether an SAE has occurred. The initial information submitted 
should include the anticipated date of delivery (see below for information related to 
termination of pregnancy). 
!
If EDP occurs in a participant or participant’s partner, the investigator must report 
this information to Pfizer Safety using the CT SAE Report Form and an EDP 
Supplemental Form, regardless of whether an SAE has occurred. Details of the 
pregnancy will be collected after the start of study intervention and until a minimum 
of 28 calendar days after the last administration of study intervention.
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!
If EDP occurs in the setting of environmental exposure, the investigator must report 
information to Pfizer Safety using the CT SAE Report Form and an EDP 
Supplemental Form. Since the exposure information does not pertain to the 
participant enrolled in the study, the information is not recorded on a CRF; however, 
a copy of the completed report is maintained in the investigator site file.
!
Follow-up is conducted to obtain general information on the pregnancy and its 
outcome for all EDP reports with an unknown outcome. The investigator will follow 
the pregnancy until completion (or until pregnancy termination) and notify Pfizer 
Safety of the outcome as a follow-up to the initial report. In the case of a live birth, 
the structural integrity of the neonate can be assessed at the time of birth. In the event 
of a termination, the reason(s) for termination should be specified and, if clinically 
possible, the structural integrity of the terminated fetus should be assessed by gross 
visual inspection (unless pre-procedure test findings are conclusive for a congenital 
anomaly and the findings are reported).
Abnormal pregnancy outcomes are considered SAEs. If the outcome of the pregnancy meets 
the criteria for an SAE (ie, ectopic pregnancy, spontaneous abortion, intrauterine fetal 
demise, neonatal death, or congenital anomaly in a live-born baby, a terminated fetus, an 
intrauterine fetal demise, or a neonatal death), the investigator should follow the procedures 
for reporting SAEs. Additional information about pregnancy outcomes that are reported to 
Pfizer Safety as SAEs follows: 
!
Spontaneous abortion including miscarriage and missed abortion should be reported 
as an SAE;
!
Neonatal deaths that occur within 1 month of birth should be reported, without regard 
to causality, as SAEs. In addition, infant deaths after 1 month should be reported as 
SAEs when the investigator assesses the infant death as related or possibly related to 
exposure to the study intervention. 
Additional information regarding the EDP may be requested by the sponsor. Further 
follow-up of birth outcomes will be handled on a case-by-case basis (eg, follow-up on 
preterm infants to identify developmental delays). In the case of paternal exposure, the 
investigator will provide the participant with the Pregnant Partner Release of Information 
Form to deliver to his partner. The investigator must document in the source documents that 
the participant was given the Pregnant Partner Release of Information Form to provide to his 
partner.
8.4.5.2. Exposure During Breastfeeding
An EDB occurs if:
!
A female participant is found to be breastfeeding while receiving or after 
discontinuing study intervention. 
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!
A female nonparticipant is found to be breastfeeding while being exposed or having 
been exposed to study intervention (ie, environmental exposure). An example of 
environmental EDB is a female family member or healthcare provider who reports 
that she is breastfeeding after having been exposed to the study intervention by 
ingestion.
The investigator must report EDB to Pfizer Safety within 24 hours of the investigator’s 
awareness, irrespective of whether an SAE has occurred. The information must be reported 
using the CT SAE Report Form. When EDB occurs in the setting of environmental exposure, 
the exposure information does not pertain to the participant enrolled in the study, so the 
information is not recorded on a CRF. However, a copy of the completed report is 
maintained in the investigator site file.
An EDB report is not created when a Pfizer drug specifically approved for use in 
breastfeeding women (eg, vitamins) is administered in accordance with authorized use. 
However, if the infant experiences an SAE associated with such a drug, the SAE is reported 
together with the EDB.
8.4.5.3. Occupational Exposure
The investigator must report any instance of occupational exposure to Pfizer Safety within 24 
hours of the investigator’s awareness using the CT SAE Report Form, regardless of whether 
there is an associated SAE. Since the information about the occupational exposure does not 
pertain to a participant enrolled in the study, the information is not recorded on a CRF; 
however, a copy of the completed report is maintained in the investigator site file.
8.4.6. Cardiovascular and Death Events
Not applicable. 
8.4.7. Disease-Related Events and/or Disease-Related Outcomes Not Qualifying as AEs 
or SAEs
Not applicable.
8.4.8. Adverse Events of Special Interest
Not applicable.
8.4.8.1. Lack of Efficacy
This section is not applicable because efficacy is not yet proven in the study population and 
half of the participants are on placebo.
8.4.9. Medical Device Deficiencies
Not applicable. 
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8.4.10. Medication Errors
Medication errors may result from the administration or consumption of the study 
intervention by the wrong participant, or at the wrong time, or at the wrong dosage strength.
Medication errors are recorded and reported as follows:
Recorded on the 
Medication Error Page 
of the CRF
Recorded on the 
Adverse Event Page 
of the CRF
Reported on the CT SAE 
Report Form to Pfizer 
Safety Within 24 Hours of 
Awareness
All (regardless of whether 
associated with an AE)
Any AE or SAE associated 
with the medication error
Only if associated with an 
SAE
Medication errors include:
!
Medication errors involving participant exposure to the study intervention;
!
Potential medication errors or uses outside of what is foreseen in the protocol that do 
or do not involve the study participant.
!
The administration of expired study intervention;
!
The administration of an incorrect study intervention;
!
The administration of an incorrect dosage;
!
Two consecutive missed doses;
!
Participants who have an overall study intervention compliance ≤80% or ≥120%;
!
The administration of study intervention that has undergone temperature excursion 
from the specified storage range, unless it is determined by the sponsor that the study 
intervention under question is acceptable for use.
Whether or not the medication error is accompanied by an AE, as determined by the 
investigator, such medication errors occurring to a study participant are recorded on the 
medication error page of the CRF, which is a specific version of the AE page and, if 
applicable, any associated serious and nonserious AE(s) are recorded on the AE page of the 
CRF.
In the event of a medication dosing error, the sponsor should be notified within 24 hours. 
Medication errors should be reported to Pfizer Safety within 24 hours on a CT SAE Report
Form only when associated with an SAE.
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 7 9
8. 5. P h ar m ac o ki netics 
Bl o o d sa m ples of a p pr o xi matel y  3 m L will be c ollecte d f or meas ure me nt of plas ma 
c o nce ntrati o ns of sis u nat o vir as s pecifie d i n t he S o A . Partici pa nts ma y be re q ueste d d uri n g 
a n y sc he d ule d a n d u n pla n ne d treat me nt peri o d visits t o pr o vi de bl o o d sa m ples b y 
ve ni p u nct ure f or P K a nal ysis p ur p oses. T he act ual date a n d ti me ( 2 4 -h o ur cl oc k ti me) of eac h 
sa m ple will be rec or de d.
T he act ual ti mes ma y  c ha n ge, b ut t he n um ber of sa m ples will re mai n t he sa me. All eff orts 
will be ma de t o o btai n t he sa m ples at t he e xact n o mi nal ti me relati ve t o d osi n g. C ollecti o n of 
sa m ples o btai ne d ≤1 h o ur o utsi de t he sc he d ule d n o mi nal sa m pli n g ti me wi n d o ws will n ot be 
ca pt ure d as a pr ot oc ol de viati o n, as l o n g as t he e xact ti me of t he c ollecti o n is n ote d o n t he 
s o urce d oc u me nt a n d t he C R F. F or t he 
 partici pa nts wit h a d diti o nal P K sa m pli n g 
ti me p oi nts, c ollecti o n of sa m ples u p t o a n d i ncl u di n g 1 0 h o urs after d ose a d mi nistrati o n t hat 
are o btai ne d wit hi n 1 0 % of t he n o mi nal ti me relati ve t o d osi n g (e g, wit hi n 6 mi n utes of a 6 0 -
mi n ute sa m ple) will n ot be classifie d as a pr ot oc ol de viati o n, as l o n g as t he e xact ti me of t he 
c ollecti o n is n ote d o n t he s o urce d oc u me nt a n d t he C R F.
Sa m ples will be use d t o e val uate t he P K of sis u nat o vir. Sa m ples c ollecte d f or a nalys es of 
sis u nat o vir c o nce ntrati o n ma y als o be use d t o e val uate safet y or efficac y as pects relate d t o 
c o ncer ns arisi n g d uri n g or after t he st u d y , f or meta b olite i de ntificati o n a n d/ or e val uati o n of 
t he bi oa nalyt ical met h o d. T he data ma y be use d f or i nter nal e x pl orat or y p ur p oses. T he 
e x pl orat or y res ults ma y n ot be re p orte d i n t he C S R.
Ge netic a nal ys es will n ot be perf or me d o n t hese sa m ples. Partici pa nt c o nfi de ntialit y  will be 
mai ntai ne d.
Sa m ples c ollecte d f or meas ure me nt of c o nce ntrati o ns of sis u nat o vir will be a nal yz e d usi n g a 
vali date d a nal yt ical met h o d i n c o m plia nce wit h a p plica ble S O Ps. P ote ntial meta b olites ma y 
be a nal yz e d wit h eit her vali date d or e x pl orat or y  met h o ds.
T he P K sa m ples m ust be p r ocesse d a n d s hi p pe d as i n dicate d i n t he i nstr ucti o ns pr o vi de d t o 
t he i n vesti gat or site t o mai ntai n sa m ple i nte grit y. A n y  de viati o ns fr o m t he P K sa m ple 
ha n dli n g pr oce d ure (e g, sa m ple c ollecti o n a n d pr ocessi n g ste ps, i nteri m st ora ge or s hi p pi n g 
c o n diti o ns), i ncl u di n g a n y acti o ns ta ke n, m ust be d oc u me nte d a n d re p orte d t o t he s p o ns or. 
O n a case -b y -case basis, t he s p o ns or ma y  ma ke a deter mi nati o n as t o w het her sa m ple 
i nte grity has bee n c o m pr o mise d.
Dr u g c o nce ntrati o n i nf or mati o n t hat w o ul d u n bli n d t he st u d y  will n ot be re p orte d t o 
i n vesti gat or sites or bli n de d pers o n nel u ntil t he st u d y has bee n u n bli n de d.
A n y  c ha n ges i n t he ti mi n g or a d diti o n of ti me p oi nts f or a n y pla n ne d st u dy assess me nts m ust 
be d oc u me nte d a n d a p pr o ve d b y  t he rele va nt st u d y tea m me m ber a n d t he n arc hi ve d i n t he 
s p o ns or a n d site st u d y files, b ut will n ot c o nstit ute a pr ot oc ol a me n d me nt. T he IR B/ E C will 
be i nf or me d of a n y safet y iss ues t hat re q uire alterati o n of t he safet y m o nit ori n g sc he me or 
a me n d me nt of t he I C D.
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Endpoint: Proportion of participants with RSV-related hospitalization or death from any 
cause through Day 28.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
directly into the endpoint. 
Population-level summary: difference in proportions between treatments.
9.1.1.2. Secondary Estimands
Key Secondary Estimands
The first key secondary estimand is defined by the following attributes:
Population: non-hospitalized adults who are infected with RSV and are at high risk of severe 
illness.
Endpoint: Proportion of participants with RSV-related visits (urgent care/ED/hospital) or 
death from any cause through Day 28.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
directly into the endpoint. 
Population-level summary: difference in proportions between treatments.
The second key secondary estimand is defined by the following attributes:
Population: non-hospitalized adults who are infected with RSV and are at high risk of severe 
illness, who at randomization have either no LRTI or only nsLRTI-RSV.
Endpoint: Proportion of participants with progression of LRTI through Day 10.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
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Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
into the endpoint, ie, death will be considered progression of LRTI. 
Population-level summary: difference in proportions between treatments.
The third key secondary estimand is defined by the following attributes:
Population: non-hospitalized adults who are infected with RSV and are at high risk of severe 
illness, who at randomization have no LRTI.
Endpoint: Proportion of participants with development of LRTI through Day 10.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
into the endpoint, ie, death will be considered development of LRTI. 
Population-level summary: difference in proportions between treatments.
The fourth key secondary estimand is defined by the following attributes:
Population: non-hospitalized adults who are infected with RSV and are at high risk of severe 
illness, who at randomization have either nsLRTI-RSV or sLRTI-RSV.
Endpoint: Proportion of participants with resolution of LRTI at Day 15.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
into the endpoint, ie, death will be considered “not resolved”. 
Population-level summary: difference in proportions between treatments.
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The fifth key secondary estimand is defined by the following attributes:
Population: non-hospitalized adults who are infected with RSV and are at high risk of severe 
illness. 
Endpoint: Mean number of days alive and free from hospital stay (hospital-free days) 
through Day 28.
Treatment condition: the randomized treatment (sisunatovir or placebo). 
Intercurrent events: The intercurrent events “discontinuation from or non-compliance to the 
planned course of treatment,” “discontinuation from the study,” and “initiation of rescue or 
other concomitant medications” are addressed by including all available data in the analysis 
regardless of discontinuation, non-compliance, or use of concomitant medications. The 
composite strategy is followed for the intercurrent event of “death” by incorporating death 
directly into the endpoint. 
Population-level summary: difference in means between treatments.
Estimands for the other secondary outcome measures that are considered supportive of the 
primary and key secondary outcome measures will be provided in the statistical analysis 
plan.
9.1.2. Multiplicity Adjustment
Following the positive test of the primary endpoint, sequential testing will be performed for 
the key secondary endpoints in the following order:
!
Proportion of participants with RSV-related visits (urgent care/ED/hospital) or death 
from any cause through Day 28.
!
Proportion of participants with progression of LRTI through Day 10.
!
Proportion of participants with development of LRTI through Day 10.
!
Proportion of participants with resolution of LRTI at Day 15.
!
Mean number of days alive and free from hospital stay (hospital-free days) through 
Day 28.
A key secondary endpoint is tested only if the preceding key secondary endpoint in the 
hierarchy is determined to be significant, ie, p-value ≤ the applicable alpha level.
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The key secondary endpoints will not be tested at the second efficacy IA but will be tested 
according to the following framework [22] (see Section 9.4 for more details): 
!
If the study is stopped early for efficacy at the second efficacy IA, the key secondary 
endpoints will be tested on the accrued set of all participants available after 
enrollment has been stopped and all randomized participants have completed the 
study.
!
If the study is not stopped early for efficacy at the second efficacy IA, the key 
secondary endpoints will be tested at the conclusion of the full study, if the test for 
the primary endpoint is statistically significant at that final analysis.
9.2. Analysis Sets
For purposes of analysis, the following analysis sets are defined:
Participant Analysis Set
Description
Enrolled 
"Enrolled" means a participant, or their legally authorized 
representative, agreed to participate in this clinical study 
following completion of the informed consent process and 
the participant was randomized to study intervention. 
Full analysis set (FAS)
All participants randomly assigned to study intervention.
Safety analysis set
All participants randomly assigned to study intervention 
and who take at least 1 dose of study intervention. 
Participants will be analyzed according to the study 
intervention they received.
PK concentration 
population
All participants who received at least 1 dose of sisunatovir 
and in whom at least 1 concentration value can be 
reported.
PK parameter analysis 
population
All participants who received at least 1 dose of sisunatovir 
and in whom at least 1 of the PK parameters of interest can 
be reported.
Defined Analysis Set
Description
Modified Intent-to-Treat 
- Infected (mITT-
infected)
All participants randomly assigned to study intervention, 
who take at least 1 dose of study intervention, and who 
have confirmed RSV infection at randomization that is 
defined as detectable RSV RNA levels by RT-PCR as 
measured by the central laboratory. Participants will be 
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Defined Analysis Set
Description
analyzed according to the study intervention to which they 
were randomized. 
For the primary efficacy analysis and analyses of the key secondary endpoints, the 
mITT-infected set will be used. The Safety Analysis Set will be used in the analyses of the 
safety data.
9.3. Statistical Analyses
The SAP will be developed and finalized before any analyses are performed and will 
describe the analyses, including procedures for accounting for missing, unused, and spurious 
data. This section is a summary of the planned statistical analyses of the primary and 
secondary endpoints.
9.3.1. General Considerations
Descriptive statistics for all efficacy endpoints by treatment group and visit (as applicable) 
will be provided. 
The number of participants screened, randomized to the double blind treatment phase, 
completing the study drug administration, and completing the study will be summarized from 
the FAS. The reason for all discontinuations will be summarized by treatment group. 
Baseline demographic and other characteristics will be tabulated for the FAS and 
summarized by treatment group. Quantitative variables will be described by standard 
descriptive statistics (mean, standard deviation, minimum, and maximum), and qualitative 
variables will be summarized by frequency tables with number and proportion in each 
category (with the corresponding sample sizes).
For continuous endpoints, a mixed model repeated measures (MMRM) analysis of 
covariance will be used to analyze change from baseline over time. Estimated mean 
differences between treatments and their respective 95% CI and p‑values will be calculated.
For binary endpoints, proportions of participants with the event will be summarized for each 
group. Treatment comparisons between the groups will be presented as the difference of 
proportions with its 95% confidence interval using a similar analysis method as the primary 
endpoint.
For categorical endpoints, proportions of participants for each category will be summarized 
for each group.
For count endpoints, the total number of the events and average number of events will be 
summarized for each group. 
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 8 8
I m p utati o n of missi n g data wit hi n efficac y varia bles a n d e n d p oi nts will be c o m p ute d 
acc or di n g t o t he r ules s pecifie d i n t he S A P. Details o n c o variates t o be i ncl u de d i n m o dels 
will als o be s pecifie d i n t he S A P.
9. 3. 2. Pri m ar y E n d p oi nt/ Esti m a n d A n al ysis
9. 3. 2. 1. Defi niti o n of E n d p oi nt
T he pri mar y  e n d p oi nt is t he pr o p orti o n of partici pa nts wit h R S V-relate d h os pitalizati o n or 
deat h fr o m a n y ca use t hr o u g h Da y 2 8.
F or t he pri mar y  e n d p oi nt, h os pitalizati o n is defi ne d as ≥2 4 h o urs of ac ute care i n a h os pital 
or si milar ac ute care facilit y  (see Secti o n 8. 2. 1 ). T his i ncl u des s pecialize d ac ute me dical care 
u nit wit hi n a n assiste d li vi n g facilit y  or n ursi n g h o me.
9. 3. 2. 2. M ai n A n al ytic al A p pr o ac h
T he pri mar y  efficac y a nal ysis will be c o n d ucte d usi n g t he mI T T-i nfecte d p o p ulati o n. 
T he treat me nt differe nce i n pr o p orti o n of partici pa nts e x perie nci n g R S V-relate d 
h os pitalizati o n or deat h fr o m a n y  ca use d uri n g t he first 2 8 da ys of t he st u d y will be a nalyz e d 
b y  t he M N met h o d [2 3 ]. M ulti ple i m p utati o n will be use d t o i m p ute e n d p oi nt e ve nt stat us f or 
partici pa nts w h o disc o nti n ue pri or t o t he Da y  2 8 visit wit h o ut e x perie nci n g a n e n d p oi nt e ve nt
[2 4 ].
T he a b o ve pri mar y  a nal ysis will als o be c o n d ucte d f or t he t w o pla n ne d efficac y IAs. T w o -
si de d 9 5 % CI (a dj uste d f or t he pla n ne d i nteri m a nal yses) a n d ass ociate d p-val ue f or t he n ull 
h y p ot hesis of n o differe nce bet wee n treat me nt gr o u ps will be prese nte d. Si g nifica nce le vel 
f or assess me nt of efficac y will be determi ne d usi n g t he 
 at t he 
sec o n d efficac y IA a n d t he fi nal a nal ys is. Si g nifica nce le vel f or assess me nt of f utilit y will be 
deter mi ne d usi n g t he 
 
a p pr oac h at t he first a n d sec o n d efficac y IAs. T he o verall si g nifica nce le vel is 
set at 2. 5 % ( 1 si de d) [2 5 ] .
9. 3. 2. 3. Se nsiti vit y A n al yses
A d diti o nal se nsiti vit y  a nal yses will be descri be d i n t he S A P.
9. 3. 2. 4. S u p ple me nt ar y A n al yses
S u p ple me ntal a nal ys es will be perf or me d f or t he pri mar y  efficac y e n d p oi nt t o assess t he 
i m pact of baseli ne R S V R N A le vels b y R T-P C R as meas ure d b y t he ce ntral la b orat or y , da ys 
si nce s ym pt o m o nset, a n d R S V s u b -s pecies ( A/ B). A n ot her s u p ple me ntal a nal ysis will be 
perf or me d usi n g t he F A S. 
A d diti o nal s u p ple me ntal a nal ys es will be des cri be d i n t he S A P.
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9.3.3. Secondary Endpoints/Estimands Analysis
Proportion of participants with RSV-related visits (urgent care/ED/hospital) or death 
from any cause through Day 28
The first key secondary efficacy endpoint is the proportion of participants with RSV-related 
visits (urgent care/ED/hospital) or death from any cause through Day 28. The analysis for 
this endpoint is similar to the analysis of the primary endpoint. For this secondary endpoint, 
no minimum duration of hospitalization is required. If a patient is located in an urgent care or 
ED at time of randomization, that initial visit would not count towards assessment of this 
endpoint.
Proportion of participants with progression of LRTI through Day 10
The second key secondary efficacy endpoint is the proportion of participants with 
progression of LRTI through Day 10. Progression of LRTI is defined as progressing from no 
LRTI at randomization to nsLRTI-RSV or sLRTI-RSV, or from nsLRTI-RSV at 
randomization to sLRTI-RSV, at any time up to and including Day 10. The analysis for this 
endpoint is similar to the analysis of the primary endpoint.
Proportion of participants with development of LRTI through Day 10
The third key secondary efficacy endpoint is the proportion of participants with development 
of LRTI through Day 10. Development of LRTI is defined as not having LRTI at 
randomization but having nsLRTI-RSV or sLRTI-RSV at any time up to and including Day 
10. The analysis for this endpoint is similar to the analysis of the primary endpoint.
Proportion of participants with resolution of LRTI at Day 15
The fourth key secondary efficacy endpoint is the proportion of participants with resolution 
of LRTI at Day 15. Resolution of LRTI is defined as having nsLRTI-RSV or sLRTI-RSV at 
randomization and having no LRTI at Day 15. The analysis for this endpoint is similar to the 
analysis of the primary endpoint.
Mean number of days alive and free from hospital stay (hospital-free days) through 
Day 28
The fifth key secondary efficacy endpoint is the mean number of days alive and free from 
hospital stay (hospital-free days) through Day 28. All hospital days will be counted, 
regardless of whether or not the hospital admission or hospital day is related to RSV. The 
analysis for this endpoint will be based on a model with treatment group as a factor and 
symptom duration as a covariate.
!
Additional efficacy-related secondary endpoints
!
Proportion of participants with progression of LRTI through Day 3, 5, 15, and 28.
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!
Proportion of participants with development of LRTI through Day 3, 5, 15, and 28.
!
Proportion of participants with resolution of LRTI at Day 3, 5, 10, and 28.
!
Proportion of participants with improvement in LRTI status at Day 3, 5, 10, 15, and 
28.
!
Number of RSV related days in hospital through Day 28.
!
Number of RSV related days in ICU through Day 28.
!
Proportion of participants with a clinical response of Improvement or Resolution at 
Day 5, 10, 15, and 28. 
!
Proportion of participants with undetectable RSV viral load at each study visit 
through Day 28.
!
Change from baseline in RSV viral load at each study visit through Day 28.
Details on the definitions and analyses of secondary endpoints will be described in the SAP.
9.3.3.1. Pharmacokinetics
The plasma concentrations of sisunatovir will be listed and descriptively summarized by 
specific PK sampling windows or nominal sampling time as appropriate. Summary profiles 
(mean and median plots) of the sisunatovir plasma concentration data will be plotted using 
actual and nominal time or time windows, respectively. Mean and median profiles will be 
presented on both linear and semi-log scales.
An iterative population PK model is being developed from Phase 1 and 2 sisunatovir studies. 
This model is developed with successive updates and validations from available data as 
studies complete. The final population PK model will be used to simulate plasma 
concentration-time curves for sisunatovir for individuals (if feasible) and to calculate 
post-hoc estimates of PK parameters (CL/F, Cmax, Cmin, AUCtau and t½).
Data permitting, geometric mean of PK parameters estimated from the final population PK 
model will be summarized. A stand-alone population PK modeling and simulation analysis 
plan will be prepared, and the results will be reported in a stand-alone report outside of the 
clinical study report.
9.3.4. Tertiary/Exploratory Endpoint(s) Analysis
Analysis methodology for tertiary/exploratory endpoints will be described in the SAP.
Results of tertiary/exploratory endpoint analyses will be described in the CSR to the extent 
possible. Due to the exploratory nature of the endpoints, the associated data analyses may not 
be complete at the time of CSR preparation. If results of tertiary/exploratory endpoint 
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 9 1
a nal ys es ca n n ot be i ncl u de d i n t he C S R, t he y will be disse mi nate d t o t he scie ntific 
c o m m u nit y t o t he e xte nt possi ble t hr o u g h prese ntati o n at scie ntific meeti n gs a n d/ or 
p u blicati o n i n peer -re vie we d scie ntific j o ur nals.
9. 3. 5. S afet y A n al yses
All safet y a nal ys es will be perf or me d o n t he safet y p o p ulati o n.
T he safet y assess me nts i ncl u de A Es, la b orat or y  assess me nts, p h ysical e xa mi nati o ns, a n d 
vital si g ns. S u m maries of i nci de nce rates of A Es (e g, treat me nt -e mer ge nt A Es, S A Es, 
disc o nti n uati o ns d ue t o A Es) will be perf or me d, as will s u m maries of cate g orical 
assess me nts of la b orat or y a n d vital si g ns data. N o f or mal statistical a nalys is will be 
c o n d ucte d o n a n y of t he safet y data liste d a b o ve.    
9. 3. 6. Ot her A n al yses 
P har mac o ge n o mic or bi o mar ker data fr o m Retai ne d Researc h Sa m ples ma y be c ollecte d 
d uri n g or after t he t rial a n d retai ne d f or f ut ure a nal yses; t he res ults of s uc h a nalys es are n ot 
pla n ne d t o be i ncl u de d i n t he C S R. 
L o n g -ter m healt h o utc o mes a n d healt hcare utilizati o n fr o m real w orl d data i n t he U nite d 
States will be c ollecte d d uri n g a n d after t he trial a n d retai ne d f or f ut ure a nal yses; t he res ults 
of s uc h a nal ys es are n ot pla n ne d t o be i ncl u de d i n t he C S R.
9. 4. I nteri m A n al yses
A pla n ne d efficac y  IA f or f utilit y  will be c o n d ucte d a n d re vie we d by a n i n de pe n de nt E -D M C 
after a p pr o xi matel y 4 5 % of pla n ne d partici pa nts i n t he mIT T -i nfecte d a nal ysis set (ie, 
a p pr o xi matel y 4 5 % of  
partici pa nts) c o m plete Da y 2 8 assess me nts or ha ve 
disc o nti n ue d t he st u d y . A sec o n d pla n ne d efficac y IA f or earl y efficac y  a n d f utilit y wit h a 
sa m ple size re-assess me nt will be c o n d ucted a n d re vie we d b y a n i n de pe n de nt E-D M C after 
a p pr o xi matel y 6 5 % of pla n ne d partici pa nts i n t he mIT T -i nfecte d a nalys is set 
(ie, a p pr o xi matel y 6 5 % of 
 partici pa nts) c o m plete Da y 2 8 assess me nts or ha ve 
disc o nti n ue d t he st u d y . B ot h t he f utilit y r ules are n o n -bi n di n g. 
At t he ti me of pla n ni n g t he P hase 2/ 3 st u d y , t here was u ncertai nt y a b o ut t he rate of R S V-
relate d h os pitalizati o n or deat h i n t he pri mar y a nal ysis p o p ulati o n a n d a b o ut t he treat me nt 
effect of sis u nat o vir. He nce, a sa m ple size re -assess me n t will be c o n d ucte d d uri n g t he sec o n d 
efficac y IA base d o n c o n diti o nal p o wer [2 6 ]. T he sa m ple size ca n be a dj uste d o ne ti me if t he 
c o n diti o nal p o wer falls bet wee n 3 0 % a n d 9 0 %, a n d t he i ncrease will be 
A 
well -esta blis he d met h o d descri be d b y C ui, H u n g, a n d Wa n g ( 1 9 9 9) [2 7 ] will be use d t o 
c o ntr ol t he T ype I err or pr o ba bilit y [2 8 ].
T he n o mi nal si g nifica nce le vel f or t he pla n ne d i nteri m a n d fi nal pr o p orti o n of 
h os pitalizati o n/ deat h a nal y ses is deter mi ne d b y mea ns of t he 
 
wit h a n o verall 1 -si de d ty pe I err or rate of 2. 5 %.
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 9 4
a ntici pate d t hat at least 
% of partici pa nts will ha ve n o L R TI or o nl y ns L R TI -R S V at 
ra n d o mizati o n, a n d t h us be i ncl u de d i n t his a nalys is. Ass u mi n g 
% of place b o partici pa nts 
will e x perie nce pr o gressi o n, a n d t hat sis u nat o vir will pr o vi de a 
% relati ve re d ucti o n fr o m 
place b o i n t he e ve nt rate, mar gi nal p o wer after st o p pi n g d ue t o earl y efficac y or pr ocee di n g 
t o f ull st u d y c o ncl usi o n is e x pecte d t o be at least 9 0 %. 
1 0. S U P P O R TI N G D O C U M E N T A TI O N A N D O P E R A TI O N A L C O N SI D E R A TI O N S
1 0. 1. A p pe n di x 1: Re g ul at or y, Et hic al, a n d St u d y O versi g ht C o nsi der ati o ns
1 0. 1. 1. Re g ul at or y a n d Et hic al C o nsi der ati o ns
T his st u d y  will be c o n d ucte d i n acc or da nce wit h t he pr ot oc ol a n d wit h t he f oll o wi n g:

C o nse ns us et hical pri nci ples deri ve d fr o m i nter nati o nal g ui deli nes, i ncl u di n g t he 
Declarati o n of Helsi n ki a n d CI O M S I nter nati o nal Et hical G ui deli nes;

A p plica ble I C H G C P g ui deli nes;

A p plica ble la ws a n d re g ulati o ns, i ncl u di n g a p plica ble pri vac y la ws.
T he pr ot oc ol, pr ot oc ol a me n d me nts, I C D, S R S D(s), a n d ot her rele va nt d oc u me nts (e g, 
a d vertise me nts) m ust be re vie we d a n d a p pr o ve d b y t he s p o ns or, s u b mitte d t o a n IR B/ E C b y  
t he i n vesti gat or, a n d re vie we d a n d a p pr o ve d b y t he IR B/ E C bef ore t he st u d y  is i nitiate d.
A n y  a me n d me nts t o t he pr ot oc ol will re q uire I R B/ E C a p pr o val bef ore i m ple me ntati o n of 
c ha n ges ma de t o t he st u d y desi g n, e xce pt f or c ha n ges necessar y  t o eli mi nate a n i m me diate 
hazar d t o st u d y  partici pa nts.
Pr ot oc ols a n d a n y s u bsta ntial a me n d me nts t o t he pr ot oc ol will re q uire healt h a ut h orit y  
a p pr o val pri or t o i nitiati o n e xce pt f or c ha n ges necessar y t o eli mi nate a n i m me diate hazar d t o 
st u d y partici pa nts.
T he i n vesti gat or will be res p o nsi ble f or t he f oll o wi n g:

Pr o vi di n g writte n s u m maries of t he stat us of t he st u d y  t o t he I R B/ E C a n n uall y or 
m ore fre q ue ntl y  i n acc or da nce wit h t he re q uire me nts, p olicies, a n d pr oce d ures 
esta blis he d b y t he I R B/ E C;

N otif y i n g t he I R B/ E C of S A Es or ot her si g nifica nt safety fi n di n gs as re q uire d b y  
I RB/ E C pr oce d ures;

Pr o vi di n g o versi g ht of t he c o n d uct of t he st u d y at t he site a n d a d here nce t o 
re q uire me nts of 2 1 C F R, I C H G C P g ui deli nes, t he IR B/ E C, E ur o pea n re g ulati o n 
5 3 6/ 2 0 1 4 f or cli nical st u dies, E ur o pea n Me dical De vice Re g ulati o n 2 0 1 7/ 7 4 5 f or 
cli nical de vice researc h, a n d all ot her a p plica ble l ocal re g ulati o ns.
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI

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10.1.1.1. Reporting of Safety Issues and Serious Breaches of the Protocol or ICH GCP
In the event of any prohibition or restriction imposed (ie, clinical hold) by an applicable 
regulatory authority in any area of the world, or if the investigator is aware of any new 
information that might influence the evaluation of the benefits and risks of the study 
intervention, Pfizer should be informed immediately. 
In addition, the investigator will inform Pfizer immediately of any urgent safety measures 
taken by the investigator to protect the study participants against any immediate hazard, and 
of any serious breaches of this protocol or of the ICH GCP guidelines that the investigator
becomes aware of.
10.1.2. Financial Disclosure
Investigators and subinvestigators will provide the sponsor with sufficient, accurate financial 
information as requested to allow the sponsor to submit complete and accurate financial 
certification or disclosure statements to the appropriate regulatory authorities. Investigators 
are responsible for providing information on financial interests during the course of the study 
and for 1 year after completion of the study.
10.1.3. Informed Consent Process 
The investigator or the investigator’s representative will explain the nature of the study, 
including the risks and benefits, to the participant or their legally authorized representative
and answer all questions regarding the study. The participant or their legally authorized 
representative should be given sufficient time and opportunity to ask questions and to decide 
whether or not to participate in the trial.
Vulnerable participants, such as elderly individuals with impaired cognitive function, may be 
enrolled, with the consent process being completed by their legally authorized representative, 
if the expected benefits of receiving sisunatovir outweigh the risks of trial participation, in 
the opinion of the investigator.
Participants must be informed that their participation is voluntary. Participants or their legally 
authorized representative (if allowed by local regulations) will be required to sign a statement 
of informed consent that meets the requirements of 21 CFR 50, local regulations, ICH 
guidelines, privacy and data protection requirements, where applicable, and the IRB/EC or 
study center.
The investigator must ensure that each participant or their legally authorized representative is 
fully informed about the nature and objectives of the study, the sharing of data related to the 
study, and possible risks associated with participation, including the risks associated with the 
processing of the participant’s personal data. 
The participant or their legally authorized representative must be informed that their personal 
study-related data will be used by the sponsor in accordance with local data protection law. 
The level of disclosure must also be explained to the participant or their legally authorized 
representative.
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The participant or their legally authorized representative must be informed that their medical 
records may be examined by Clinical Quality Assurance auditors or other authorized 
personnel appointed by the sponsor, by appropriate IRB/EC members, and by inspectors 
from regulatory authorities.
The investigator further must ensure that each study participant or their legally authorized 
representative is fully informed about their right to access and correct their personal data and 
to withdraw consent for the processing of their personal data.
The medical record must include a statement that written informed consent was obtained 
before the participant was enrolled in the study and the date on which the written consent was 
obtained. The authorized person obtaining the informed consent must also sign the ICD.
Participants or their legally authorized representative must be reconsented to the most current 
version of the IRB/EC-approved ICD(s) during their participation in the study as required per 
local regulations.
A copy of the ICD(s) must be provided to the participant or their legally authorized 
representative (if allowed by local regulations).
10.1.3.1. Electronic Consent 
Participants may be able to experience the informed consent process by electronic means 
(eConsent). The eConsent process includes an electronic presentation of the informed 
consent document (eICD), clinical trial educational components (as applicable), and 
electronic signatures (if allowed by local regulations). The use of eConsent does not replace 
or alter the ICD content or informed consent process as described above. The eConsent 
process complies with applicable regulations and sponsor policies to ensure reliability and 
data privacy.
10.1.4. Data Protection
All parties will comply with all applicable laws, including laws regarding the implementation 
of organizational and technical measures to ensure protection of participant data.
Participants’ personal data will be stored at the study site in encrypted electronic and/or paper 
form and will be password protected or secured in a locked room to ensure that only 
authorized study staff have access. The study site will implement appropriate technical and 
organizational measures to ensure that the personal data can be recovered in the event of 
disaster. In the event of a potential personal data breach, the study site will be responsible for 
determining whether a personal data breach has in fact occurred and, if so, providing breach 
notifications as required by law.
To protect the rights and freedoms of participants with regard to the processing of personal 
data, participants will be assigned a single, participant-specific numerical code. Any 
participant records or data sets that are transferred to the sponsor will contain the numerical 
code; participant names will not be transferred. All other identifiable data transferred to the 
sponsor will be identified by this single, participant-specific code. The study site will 
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maintain a confidential list of participants who participated in the study, linking each 
participant’s numerical code to their actual identity and medical record ID. In case of data 
transfer, the sponsor will protect the confidentiality of participants’ personal data consistent 
with the clinical study agreement and applicable privacy laws.
Information technology systems used to collect, process, and store study-related data are 
secured by technical and organizational security measures designed to protect such data 
against accidental or unlawful loss, alteration, or unauthorized disclosure or access.
The sponsor maintains SOPs on how to respond in the event of unauthorized access, use, or 
disclosure of sponsor information or systems.
10.1.5. Committees Structure
10.1.5.1. Data Monitoring Committee 
This study will use an E-DMC. The E-DMC is independent of the study team and includes 
only external members. The E-DMC charter describes the role of the E-DMC in more detail.
The E-DMC will be responsible for ongoing monitoring of the safety of participants in the 
study according to the charter. The recommendations made by the E-DMC will be forwarded 
to the appropriate authorized Pfizer personnel for review and final decision. Pfizer will 
communicate such decisions, which may include summaries of aggregate analyses of 
endpoint events and of safety data that are not endpoints, to regulatory authorities and 
investigators, as appropriate. 
10.1.6. Dissemination of Clinical Study Data
Pfizer fulfills its commitment to publicly disclose clinical study results through posting the 
results of studies on www.clinicaltrials.gov (ClinicalTrials.gov), the EudraCT/CTIS, and/or 
www.pfizer.com, and other public registries and websites in accordance with applicable local 
laws/regulations. In addition, Pfizer reports study results outside of the requirements of local 
laws/regulations pursuant to its SOPs.
In all cases, study results are reported by Pfizer in an objective, accurate, balanced, and 
complete manner and are reported regardless of the outcome of the study or the country in 
which the study was conducted.
www.clinicaltrials.gov
Pfizer posts clinical trial results on www.clinicaltrials.gov for Pfizer-sponsored interventional 
studies (conducted in patients) that evaluate the safety and/or efficacy of a product, 
regardless of the geographical location in which the study is conducted. These results are 
submitted for posting in accordance with the format and timelines set forth by US law.
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EudraCT/CTIS
Pfizer posts clinical trial results on EudraCT/CTIS for Pfizer-sponsored interventional studies 
in accordance with the format and timelines set forth by EU requirements.
www.pfizer.com
Pfizer posts CSR synopses and plain-language study results summaries on www.pfizer.com 
for Pfizer-sponsored interventional studies at the same time the corresponding study results 
are posted to www.clinicaltrials.gov. CSR synopses will have personally identifiable 
information anonymized.
Documents within marketing applications
Pfizer complies with applicable local laws/regulations to publish clinical documents included 
in marketing applications. Clinical documents include summary documents and CSRs 
including the protocol and protocol amendments, sample CRFs, and SAPs. Clinical 
documents will have personally identifiable information anonymized.
Data sharing
Pfizer provides researchers secure access to participant-level data or full CSRs for the 
purposes of “bona-fide scientific research” that contributes to the scientific understanding of 
the disease, target, or compound class. Pfizer will make data from these trials available 
18 months after study completion. Participant-level data will be anonymized in accordance 
with applicable privacy laws and regulations. CSRs will have personally identifiable 
information anonymized.
Data requests are considered from qualified researchers with the appropriate competencies to 
perform the proposed analyses. Research teams must include a biostatistician. Data will not 
be provided to applicants with significant conflicts of interest, including individuals 
requesting access for commercial/competitive or legal purposes.
10.1.7. Data Quality Assurance
All participant data relating to the study will be recorded on printed or electronic CRF unless 
transmitted to the sponsor or designee electronically (eg, laboratory data). The investigator is 
responsible for verifying that data entries are accurate and correct by physically or 
electronically signing the CRF.
Guidance on completion of CRFs will be provided in the CRF Completion Requirements 
document.
The investigator must ensure that the CRFs are securely stored at the study site in encrypted 
electronic and or paper form and are password protected or secured in a locked room to 
prevent access by unauthorized third parties.
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QTLs are predefined parameters that are monitored during the study. Important deviations 
from the QTLs and any remedial actions taken will be summarized in the CSR.
The investigator must permit study-related monitoring, audits, IRB/EC review, and 
regulatory agency inspections and provide direct access to source records and documents. 
This verification may also occur after study completion. It is important that the 
investigator(s) and their relevant personnel are available during the monitoring visits and 
possible audits or inspections and that sufficient time is devoted to the process.
Monitoring details describing strategy, including definition of study-critical data items and 
processes (eg, risk-based initiatives in operations and quality such as risk management and 
mitigation strategies and analytical risk-based monitoring), methods, responsibilities, and 
requirements, including handling of noncompliance issues and monitoring techniques 
(central, virtual, or on-site monitoring), are provided in the data management plan and 
monitoring plan maintained and utilized by the sponsor or designee. 
The sponsor or designee is responsible for the data management of this study, including 
quality checking of the data.
Records and documents, including signed ICDs, pertaining to the conduct of this study must 
be retained by the investigator for 15 years after study completion unless local regulations or 
institutional policies require a longer retention period. No records may be destroyed during 
the retention period without the written approval of the sponsor. No records may be 
transferred to another location or party without written notification to the sponsor. The 
investigator must ensure that the records continue to be stored securely for as long as they are 
maintained.
When participant data are to be deleted, the investigator will ensure that all copies of such 
data are promptly and irrevocably deleted from all systems.
The investigator(s) will notify the sponsor or its agents immediately of any regulatory 
inspection notification in relation to the study. Furthermore, the investigator will cooperate 
with the sponsor or its agents to prepare the investigator site for the inspection and will allow 
the sponsor or its agent, whenever feasible, to be present during the inspection. The 
investigator site and investigator will promptly resolve any discrepancies that are identified 
between the study data and the participant’s medical records. The investigator will promptly 
provide copies of the inspection findings to the sponsor or its agent. Before response 
submission to the regulatory authorities, the investigator will provide the sponsor or its 
agents with an opportunity to review and comment on responses to any such findings.
10.1.8. Source Documents
Source documents provide evidence for the existence of the participant and substantiate the 
integrity of the data collected. Source documents are filed at the investigator site.
Data reported on the CRF or entered in the eCRF that are from source documents must be 
consistent with the source documents or the discrepancies must be explained. The 
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investigator may need to request previous medical records or transfer records, depending on 
the study. Also, current medical records must be available.
Definition of what constitutes a source document and its origin can be found in the Source 
Document Locator, which is maintained by the sponsor. Description of the use of the 
computerized system is documented in the data management plan, which is maintained by 
the sponsor. 
The investigator must maintain accurate documentation (source record) that supports the 
information entered in the CRF.
The sponsor or designee will perform monitoring to confirm that data entered into the CRF 
by authorized site personnel are accurate, complete, and verifiable from source documents; 
that the safety and rights of participants are being protected; and that the study is being 
conducted in accordance with the currently approved protocol and any other study 
agreements, ICH GCP guidelines, and all applicable regulatory requirements.
10.1.9. Use of Medical Records 
In certain situations, sponsor review of redacted copies of participant medical records, for 
instance follow up of SAE may be performed, where ethically and scientifically justified and 
permitted by local regulations, to ensure participant safety. 
Due to the potential for a participant to be re-identified from their medical records, the 
following actions must be taken when medical records are sent to the sponsor or sponsor 
designee:
!
The investigator or site staff must redact personal information from the medical 
record. The personal information includes, but is not limited to, the following: 
participant names or initials, participant dates (eg, birth date, date of hospital 
admission/discharge, date of death), participant identification numbers (eg, Social 
Security number, health insurance number, medical record number, 
hospital/institution identifier), participant location information (eg, street address, 
city, country, postal code, IP address), participant contact information (eg, 
telephone/fax number, email address).
!
Each medical record must be transmitted to the sponsor or sponsor designee using 
systems with technical and organizational security measures to ensure the protection 
of personal data (eg, Florence is the preferred system if available). 
!
There may be unplanned situations where the sponsor may request medical records 
(eg, sharing medical records so that the sponsor can provide study-related advice to 
the investigator). The medical records should be submitted according to the procedure 
described above. 
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10.1.10. Study and Site Start and Closure
The study start date is the date of the first participant’s first visit.
The sponsor designee reserves the right to close the study site or terminate the study at any 
time for any reason at the sole discretion of the sponsor, including (but not limited to) 
regulatory authority decision, change in opinion of the IRB/EC, or change in benefit-risk 
assessment. Study sites will be closed upon study completion. A study site is considered 
closed when all required documents and study supplies have been collected and a study-site 
closure visit has been performed.
The investigator may initiate study-site closure at any time upon notification to the sponsor 
or designee/CRO if requested to do so by the responsible IRB/EC or if such termination is 
required to protect the health of study participants.
Reasons for the early closure of a study site by the sponsor may include but are not limited 
to:
!
Failure of the investigator to comply with the protocol, the requirements of the 
IRB/EC or local health authorities, the sponsor’s procedures, or the ICH GCP 
guidelines;
!
Inadequate recruitment of participants by the investigator; 
!
Discontinuation of further study intervention development.
If the study is prematurely terminated or suspended, the sponsor shall promptly inform the 
investigators, the ECs/IRBs, the regulatory authorities, and any CRO(s) used in the study of 
the reason for termination or suspension, as specified by the applicable regulatory 
requirements. The investigator shall promptly inform the participant and should assure 
appropriate participant therapy and/or follow-up.
Study termination is also provided for in the clinical study agreement. If there is any conflict 
between the contract and this protocol, the contract will control as to termination rights.
10.1.11. Publication Policy
For multicenter trials, the primary publication will be a joint publication developed by the 
investigator and Pfizer reporting the primary endpoint(s) of the study covering all study sites. 
The investigator agrees to refer to the primary publication in any subsequent publications. 
Pfizer will not provide any financial compensation for the investigator’s participation in the 
preparation of the primary congress abstract, poster, presentation, or primary manuscript for 
the study.
Investigators are free to publish individual center results that they deem to be clinically 
meaningful after publication of the overall results of the study or 12 months after primary 
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completion date or study completion at all sites, whichever occurs first, subject to the other 
requirements described in this section.
The investigator will provide Pfizer an opportunity to review any proposed publication or 
any other type of disclosure of the study results (collectively, “publication”) before it is 
submitted or otherwise disclosed and will submit all publications to Pfizer 30 days before 
submission. If any patent action is required to protect intellectual property rights, the 
investigator agrees to delay the disclosure for a period not to exceed an additional 60 days 
upon request from Pfizer. This allows Pfizer to protect proprietary information and to provide 
comments, and the investigator will, on request, remove any previously undisclosed 
confidential information before disclosure, except for any study-intervention or Pfizer-related 
information necessary for the appropriate scientific presentation or understanding of the 
study results. For joint publications, should there be disagreement regarding interpretation 
and/or presentation of specific analysis results, resolution of, and responsibility for, such 
disagreements will be the collective responsibility of all authors of the publication.
For all publications relating to the study, the investigator and Pfizer will comply with 
recognized ethical standards concerning publications and authorship, including those 
established by the International Committee of Medical Journal Editors. The investigator will 
disclose any relationship with Pfizer and any relevant potential conflicts of interest, including 
any financial or personal relationship with Pfizer, in any publications. All authors will have 
access to the relevant statistical tables, figures, and reports (in their original format) required 
to develop the publication.
10.1.12. Sponsor’s Medically Qualified Individual 
The sponsor will designate a medically qualified individual (MQI, also known as the medical 
monitor) to advise the investigator on study-related medical questions. The contact 
information for the study medical monitor is documented in the Study Team Contact List 
located in the supporting study documentation/study portal.  
Participants are provided with a Pfizer study information card at the time of informed consent 
which includes contact information for their investigator in case of study-related medical 
questions. The study information card contains, at a minimum, (a) study number, (b) 
participant’s study identification number, and (c) principal investigator contact information.
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10.2. Appendix 2: Clinical Laboratory Tests
The following safety laboratory tests will be performed at times defined in the SoA section of 
this protocol. Additional laboratory results may be reported on these samples as a result of 
the method of analysis or the type of analyzer used by the clinical laboratory, or as derived 
from calculated values; for example: calculation of estimated kidney function. These 
additional tests would not require additional collection of blood. Unscheduled clinical 
laboratory measurements may be obtained at any time during the study to assess any 
perceived safety issues.
Table 6.
Protocol-Required Laboratory Assessments
Hematology
Chemistry
Other
Hemoglobin
Hematocrit
RBC count
Platelet count
WBC count
Total neutrophils (Abs)
Eosinophils (Abs)
Monocytes (Abs)
Basophils (Abs)
Lymphocytes (Abs)
Urea 
Creatinine 
Cystatin Ca (at Screening or Baseline)
Sodium
Potassium
AST, ALT
GGT
Total bilirubin
Alkaline phosphatase
Albumin
Total protein
Fasting glucose
At screening:
FSHb
Pregnancy test (β-hCG)c
a.
Cystatin C (Scys): Screening or Baseline Scys may help differentiate post-baseline DIKI from DICI. 
Post-baseline, Scys is measured if and only if serum creatinine increase post-baseline is observed (see 
Section 7.1).
b.
For confirmation of postmenopausal status only.
c.
Local urine testing will be standard for the protocol unless serum testing is required by local regulation 
or IRB/EC. 
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Table 7.
Protocol-Required Laboratory Assessments – Reflex Testing
Hematology
Chemistry
If Hb/RBC abnormal: 
MCV, MCH, MCHC 
Neutrophils (%) 
Eosinophils (%) 
Basophils (%) 
Lymphocytes (%) 
Monocytes (%) 
RBC morphology 
RBC distribution width
Required: 
For suspected DILI:
AST/ALT 
T bili, albumin, CK, direct and indirect bili, GGT, PT/INR, eosinophils (%), 
alkaline phosphatase. 
The following additional testing may be warranted:
Acetaminophen/paracetamol or 
protein adduct levels 
Hepatitis serology (even if screening negative) 
Total bile acids
Liver imaging
For suspected DICI/DIKI: 
Creatinine (Screat) 
Cystatin Ca (Scys) 
eGFR (Screat only and combined Screat+Scys)b
Urine albumin-to-creatinine-ratio (UACR) 
a.
Cystatin C (Scys): Screening or Baseline Scys is recommended to help differentiate post-baseline 
DIKI from DICI. Post-baseline, Scys is measured if and only if serum creatinine increase post-
baseline is observed (see Section 7.1).
b.
Screening and Baseline eGFR is measured with creatinine (Screat)-based formula. Age-specific 
kidney function calculation (see Section 10.7.2) is recommended to assess presence or absence of 
post-baseline change in kidney function.
The investigator must review the laboratory report, document this review, and record any 
clinically relevant changes occurring during the study in the AE section of the CRF.
Laboratory/analyte results that could unblind the study and have been collected for the 
purpose of the study will not be reported to investigator sites or other blinded personnel until 
the study has been unblinded.
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nonserious AEs; and (3) exposure to the study intervention under study during pregnancy
or breastfeeding, and occupational exposure. 
It should be noted that the CT SAE Report Form for reporting of SAE information is not 
the same as the AE page of the CRF. When the same data are collected, the forms must be 
completed in a consistent manner. AEs should be recorded using concise medical 
terminology and the same AE term should be used on both the CRF and the CT SAE 
Report Form for reporting of SAE information.
Safety Event
Recorded on the CRF
Reported on the CT SAE 
Report Form to Pfizer 
Safety Within 24 Hours of 
Awareness
SAE
All
All
Nonserious AE
All
All nonserious AEs leading 
to discontinuation of study 
intervention
None
Exposure to the study 
intervention under study 
during pregnancy or 
breastfeeding 
All AEs or SAEs associated 
with EDP or EDB
All nonserious AEs leading 
to permanent 
discontinuation or SAEs 
associated with EDP or
EDB. 
Note: Instances of EDP or 
EDB not associated with an 
AE or SAE are not captured 
in the CRF
All instances of EDP are 
reported (whether or not 
there is an associated 
SAE)*
Notification of EDP alone 
(not associated with an AE 
or SAE) is not required 
when the study population 
is pregnant women. 
However, if the mother or 
the fetus experiences any 
SAE, the information is 
reported to Pfizer Safety
All instances of EDB are 
reported (whether or not 
there is an associated 
SAE)**
Environmental or 
occupational exposure to 
the product under study to 
a nonparticipant (not 
involving EDP or EDB)
None. Exposure to a study 
nonparticipant is not 
collected on the CRF
The exposure (whether or 
not there is an associated 
AE or SAE) must be 
reported***
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10.4. Appendix 4: Contraceptive and Barrier Guidance 
10.4.1. Male Participant Reproductive Inclusion Criteria
No contraception methods are required for male participants in this study, as the calculated 
safety margin is ≥100-fold between the estimated maternal exposure due to seminal transfer 
and the NOAEL for serious manifestations of developmental toxicity in nonclinical studies. 
10.4.2. Female Participant Reproductive Inclusion Criteria
The criteria below are part of Inclusion Criterion 1 (Age and Sex; Section 5.1) and specify 
the reproductive requirements for including female participants. Refer to Section 10.4.4 for a 
complete list of contraceptive methods permitted in the study. 
!
A female participant is eligible to participate if she is not pregnant or breastfeeding 
and at least 1 of the following conditions applies:
!
Is not a WOCBP (see definition in Section 10.4.3).
OR
!
Is a WOCBP and agrees to use a highly effective contraceptive method (failure 
rate of <1% per year) during the intervention period and for at least 28 days after 
the last dose of study intervention, which corresponds to the time needed to 
eliminate any reproductive safety risk of the study intervention(s). If a highly 
effective, user-dependent method is chosen, she agrees to concurrently use an 
effective barrier method of contraception. The investigator should evaluate the 
effectiveness of the contraceptive method in relationship to the first dose of study 
intervention.
The investigator is responsible for review of medical history, menstrual history, and recent 
sexual activity to decrease the risk for inclusion of a woman with an early undetected 
pregnancy. 
10.4.3. Woman of Childbearing Potential
A woman is considered fertile following menarche and until becoming postmenopausal 
unless permanently sterile (see below).
If fertility is unclear (eg, amenorrhea or oligomenorrhea) and a menstrual cycle cannot be 
confirmed before the first dose of study intervention, additional evaluation should be 
considered.
Women in the following categories are not considered WOCBP:
1. Premenarchal.
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2. Premenopausal female with 1 of the following:
!
Documented hysterectomy;
!
Documented bilateral salpingectomy;
!
Documented bilateral oophorectomy.
For individuals with permanent infertility due to a medical cause other than the above (eg, 
mullerian agenesis, androgen insensitivity), investigator discretion should be applied to 
determining study entry.
Note: Documentation for any of the above categories can come from the site personnel’s 
review of the participant’s medical records, medical examination, or medical history 
interview. The method of documentation should be recorded in the participant’s medical 
record for the study.
3. Postmenopausal female:
!
A postmenopausal state is defined as no menses for 12 months without an alternative 
medical cause. In addition:
!
A high FSH level in the postmenopausal range must be used to confirm a 
postmenopausal state in women under 60 years of age and not using hormonal 
contraception or HRT. 
!
A female on HRT and whose menopausal status is in doubt will be required to use 
one of the highly effective nonestrogen hormonal contraception methods if she 
wishes to continue her HRT during the study. Otherwise, she must discontinue 
HRT to allow confirmation of postmenopausal status before study enrollment.
10.4.4. Contraception Methods
Contraceptive use by men or women should be consistent with local availability/regulations 
regarding the use of contraceptive methods for those participating in clinical trials.
The following contraceptive methods are appropriate for this study:
Highly Effective Methods That Have Low User Dependency 
1. Implantable progestogen-only hormone contraception associated with inhibition of 
ovulation.
2. Intrauterine device.
3. Intrauterine hormone-releasing system.
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4. Bilateral tubal occlusion.
5. Vasectomized partner:
!
Vasectomized partner is a highly effective contraceptive method provided that the 
partner is the sole sexual partner of the WOCBP and the absence of sperm has 
been confirmed. If not, an additional highly effective method of contraception 
should be used. The spermatogenesis cycle is approximately 90 days.
Highly Effective Methods That Are User Dependent 
6. Combined (estrogen- and progestogen-containing) hormonal contraception associated 
with inhibition of ovulation:
!
Oral + barrier*
!
Intravaginal + barrier*
!
Transdermal + barrier*
7. Progestogen-only hormone contraception associated with inhibition of ovulation:
!
Oral + barrier*
!
Injectable + barrier*
8. Sexual abstinence
!
Sexual abstinence is considered a highly effective method only if defined as 
refraining from heterosexual intercourse during the entire period of risk associated 
with the study intervention. The reliability of sexual abstinence needs to be 
evaluated in relation to the duration of the study and the preferred and usual 
lifestyle of the participant.
* Acceptable barrier methods to be used concomitantly with options 6 or 7 for the study 
include any of the following:
!
Male or female condom, with or without spermicide;
!
Cervical cap, diaphragm, or sponge with spermicide;
!
A combination of male condom with either cervical cap, diaphragm, or sponge with 
spermicide (double-barrier methods).
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10.5. Appendix 5: Genetics
Use/Analysis of DNA
!
Genetic variation may impact a participant’s response to study intervention, 
susceptibility to, and severity and progression of disease. Therefore, where local 
regulations and IRBs/ECs allow, a blood sample will be collected for DNA analysis.
!
The scope of the genetic research may be narrow (eg, 1 or more candidate genes) or 
broad (eg, the entire genome), as appropriate to the scientific question under 
investigation.
!
The samples may be analyzed as part of a multistudy assessment of genetic factors 
involved in the response to sisunatovir or study interventions of this class to 
understand treatments for the disease(s) under study or the disease(s) themselves.
!
The results of genetic analyses may be reported in the CSR or in a separate study 
summary, or may be used for internal decision making without being included in a 
study report.
!
The sponsor will store the DNA samples in a secure storage space with adequate 
measures to protect confidentiality. 
!
The samples will be retained as indicated:
!
Retained Research samples will be stored indefinitely or for another period as per 
local requirements. 
!
Participants may withdraw their consent for the storage and/or use of their Retained 
Research Samples at any time by making a request to the investigator; in this case, 
any remaining material will be destroyed. Data already generated from the samples 
will be retained to protect the integrity of existing analyses. 
!
Samples for genetic research will be labeled with a code. The key between the code 
and the participant’s personally identifying information (eg, name, address) will be 
held securely at the study site. 
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10.6. Appendix 6: Liver Safety: Suggested Actions and Follow-Up Assessments
Potential Cases of Drug-Induced Liver Injury
Humans exposed to a drug who show no sign of liver injury (as determined by elevations in 
transaminases) are termed “tolerators,” while those who show transient liver injury but adapt 
are termed “adaptors.” In some participants, transaminase elevations are a harbinger of a 
more serious potential outcome. These participants fail to adapt and therefore are 
“susceptible” to progressive and serious liver injury, commonly referred to as DILI. 
Participants who experience a transaminase elevation above 3 × ULN should be monitored 
more frequently to determine if they are “adaptors” or are “susceptible.”
In the majority of DILI cases, elevations in AST and/or ALT precede T bili elevations (>2 × 
ULN) by several days or weeks. The increase in T bili typically occurs while AST/ALT is/are 
still elevated above 3 × ULN (ie, AST/ALT and T bili values will be elevated within the same 
laboratory sample). In rare instances, by the time T bili elevations are detected, AST/ALT 
values might have decreased. This occurrence is still regarded as a potential DILI. Therefore, 
abnormal elevations in either AST OR ALT in addition to T bili that meet the criteria outlined 
below are considered potential DILI (assessed per Hy’s law criteria) cases and should always 
be considered important medical events, even before all other possible causes of liver injury 
have been excluded.
The threshold of laboratory abnormalities for a potential DILI case depends on the 
participant’s individual baseline values and underlying conditions. Participants who present 
with the following laboratory abnormalities should be evaluated further as potential DILI 
(Hy’s law) cases to definitively determine the etiology of the abnormal laboratory values:
!
Participants with AST/ALT and T bili baseline values within the normal range who 
subsequently present with AST OR ALT values ≥3 × ULN AND a T bili value 
≥2 × ULN with no evidence of hemolysis and an alkaline phosphatase value 
<2 × ULN or not available.
!
For participants with baseline AST OR ALT OR T bili values above the ULN, the 
following threshold values are used in the definition mentioned above, as needed, 
depending on which values are above the ULN at baseline:
!
Preexisting AST or ALT baseline values above the normal range: AST or ALT 
values ≥2 times the baseline values AND ≥3 × ULN; or ≥8 × ULN (whichever is 
smaller).
!
Preexisting values of T bili above the normal range: T bili level increased from 
baseline value by an amount of ≥1 × ULN or if the value reaches ≥3 × ULN 
(whichever is smaller).
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Rises in AST/ALT and T bili separated by more than a few weeks should be assessed 
individually based on clinical judgment; any case where uncertainty remains as to whether it 
represents a potential Hy’s law case should be reviewed with the sponsor. 
The participant should return to the investigator site and be evaluated as soon as possible, 
preferably within 48 hours from awareness of the abnormal results. This evaluation should 
include laboratory tests, detailed history, and physical assessment.
In addition to repeating measurements of AST and ALT and T bili for suspected Hy’s law 
cases, additional laboratory tests should include albumin, CK, direct and indirect bilirubin, 
GGT, PT/INR, eosinophils (%), and alkaline phosphatase. Consideration should also be 
given to drawing a separate tube of clotted blood and an anticoagulated tube of blood for 
further testing, as needed, for further contemporaneous analyses at the time of the recognized 
initial abnormalities to determine etiology. A detailed history, including relevant information, 
such as review of ethanol, acetaminophen/paracetamol (either by itself or as a coformulated 
product in prescription or over-the-counter medications), recreational drug, or supplement 
(herbal) use and consumption, family history, sexual history, travel history, history of contact 
with a jaundiced person, surgery, blood transfusion, history of liver or allergic disease, and 
potential occupational exposure to chemicals, should be collected. Further testing for acute 
hepatitis A, B, C, D, and E infection, total bile acids, liver imaging (eg, biliary tract), and 
collection of serum samples for acetaminophen/paracetamol drug and/or protein adduct 
levels may be warranted. 
All cases demonstrated on repeat testing as meeting the laboratory criteria of AST/ALT and 
T bili elevation defined above should be considered potential DILI (Hy’s law) cases if no 
other reason for the LFT abnormalities has yet been found. Such potential DILI (Hy’s law) 
cases are to be reported as SAEs, irrespective of availability of all the results of the 
investigations performed to determine etiology of the LFT abnormalities.
A potential DILI (Hy’s law) case becomes a confirmed case only after all results of 
reasonable investigations have been received and have excluded an alternative etiology.
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10.7. Appendix 7: Kidney Safety Monitoring Guidelines
10.7.1. Laboratory Assessment of Change in Kidney Function and Detection of Kidney 
Injury
Standard kidney safety monitoring requires assessment of baseline and postbaseline Screat 
measurement to estimate kidney function [Screat-based eGFR] or creatinine clearance 
[eCrCl]). Baseline and postbaseline Scys makes it feasible to distinguish AKI from other 
causes of Screat increase. If Screat increase is confirmed after baseline, then reflex 
measurement of Scys is indicated. 
ADULTS: Currently, 2021 CKD-EPI eGFR equations (Screat only-based and combined 
Screat plus Scys-based) are valid for use in adults only. At baseline Screat and Scys values 
are needed to calculate 2021 CKD-EPI eGFR by Screat only-based equation (see Table in 
Section 10.7.2.1.) and by combined Screat plus Scys-based equation. When post-baseline 
Screat increase ≥0.3 mg/dL is confirmed, then reflex Scys measurement is needed to enable 
post-baseline comparison of eGFR changes (Screat only-based eGFR and combined Screat 
plus Scys eGFR). 
Regardless of whether kidney function monitoring tests are required as a routine safety 
monitoring procedure in the study, if the investigator or sponsor deems it necessary to further 
assess kidney safety and quantify kidney function, then these test results should be managed 
and followed per standard of care.
10.7.2. Age-Specific Kidney Function Calculation Recommendations
10.7.2.1. Adults (18 Years and Above)—2021 CKD-EPI Equations [30]
eGFR (mL/min/1.73m²)
2021 CKD-
EPI        
Screat Only
Screat
(mg/dL)
Scys
(mg/L)
Recommended eGFR Equation
Female
if ≤0.7
NA
eGFR = 143 × (Screat/0.7)-0.241 × (0.9938)Age
Female
if >0.7
NA
eGFR = 143 × (Screat/0.7)-1.200 × (0.9938)Age
Male
if ≤0.9
NA
eGFR = 142 × (Screat/0.9)-0.302 × (0.9938)Age
Male
if >0.9
NA
eGFR = 142 × (Screat/0.9)-1.200 × (0.9938)Age
2021 CKD-
EPI
Screat-Scys 
Combined
Screat
(mg/dL)
Scys
(mg/L)
Recommended eGFR Equation
Female
if ≤0.7
if ≤0.8
eGFR = 130 × (Screat/0.7)-0.219 × (Scys/0.8)-0.323 × (0.9961)Age
Female
if ≤0.7
if >0.8
eGFR = 130 × (Screat/0.7)-0.219 × (Scys/0.8)-0.778 × (0.9961)Age
Female
if >0.7
if ≤0.8
eGFR = 130 × (Screat/0.7)-0.544 × (Scys/0.8)-0.323 × (0.9961)Age
Female
if >0.7
if >0.8
eGFR = 130 × (Screat/0.7)-0.544 × (Scys/0.8)-0.778 × (0.9961)Age
Male
if ≤0.9
if ≤0.8
eGFR = 135 × (Screat/0.9)-0.144 × (Scys/0.8)-0.323 × (0.9961)Age
Male
if ≤0.9
if >0.8
eGFR = 135 × (Screat/0.9)-0.144 × (Scys/0.8)-0.778 × (0.9961)Age
Male
if >0.9
if ≤0.8
eGFR = 135 × (Screat/0.9)-0.544 × (Scys/0.8)-0.323 × (0.9961)Age
Male
if >0.9
if >0.8
eGFR = 135 × (Screat/0.9)-0.544 × (Scys/0.8)-0.778 × (0.9961)Age
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10.7.3. Kidney Function Calculation Tools
The sponsor has provided the following resources to investigational sites when required to 
calculate age-specific kidney function at Screening, Baseline, and post-Baseline visits. Site 
calculations of kidney function can be performed manually, using the age appropriate 
formulae (see Section 10.7.2) and can use recommended online kidney function calculators 
to reduce the likelihood of a calculation error. 
The United States National Kidney Foundation Online Calculators. 
!
Adults (18 years and above) - 2021 CKD-EPI Creatinine Online Calculator (eGFR): 
https://www.kidney.org/professionals/KDOQI/gfr_calculator 
o
Investigational sites are responsible to ensure that the accurate age-specific 
equation is selected and that the correct units for serum creatinine (mg/dL 
only), serum cystatin C (mg/L only), total body weight (kg only), and age 
(years). Investigators are expected to (i) review and confirm correctness of the 
kidney function calculation results and (ii) evaluate the calculated value 
within the context of historical information available to them in the 
participant’s medical record. Investigators are responsible for the clinical 
oversight of the participant eligibility process, kidney function calculation, 
and dose selection and adjustments per study protocol. Investigators are 
encouraged to direct questions or uncertainties regarding kidney function and 
dosing to the Pfizer Clinical Team and Medical Monitor, if needed.
10.7.4. Adverse Event Grading for Kidney Safety Laboratory Abnormalities
AE grading for decline in kidney function (ie, eGFR) will be according to KDIGO criteria for 
adult participants.
KDIGO criteria
grade (G)
Study 
Population
G1
G2
G3
G4
G5
Decreased 
Kidney Function 
due to either 
Acute or Chronic 
Kidney Injury 
Adult 
participants
eGFR 
(mL/min/1.73m²)
≥90 
≥60 to 89
30 to 59 
15 to 29
<15
KDIGO albuminuria 
(A) criteria
A1
A2
A3
Albumin-to-creatinine 
ratio (ACR)
<30 mg/g
OR     
30 to 300 mg/g
OR 
>300 mg/g 
OR 
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10.10. Appendix 10: Country-Specific Requirements
10.10.1. United States
Participants in the United States will be invited to participate in optional, additional research 
using real world data to describe long-term health outcomes and healthcare utilization for 12 
months after taking the study medicine. Real world data may consist of large commercially 
available databases of medical claims, billing data, pharmacy claims, and electronic health 
records. Long-term follow-up will be conducted by accessing and evaluating real-world data 
sources using a technology called Tokenization.
Study participants who consent to participate in additional research using real world data via 
tokenization will have a unique identifier generated (ie, token) through a third-party vendor.
Tokenization transforms patient identifiable information (first name, last name, sex at birth, 
date of birth and zip code) into an irreversible random string of characters that can be used to 
securely link patient-level data from the clinical study database (eg, treatment group 
assignment of sisunatovir or placebo) with real world data sources (eg, medical visits 
observed in insurance claims) to evaluate medical outcomes (eg, number and type of medical 
visits and survival) that occur after the main study ends. 
Specific instructions for sites regarding how to record data on a secure website to enable 
token generation can be found in site training materials.
10.10.1.1. Management and reporting of adverse events/adverse reactions for additional 
research using real world data
This additional research involves a combination of existing structured data and unstructured 
data, which will be converted to structured form during the implementation of the protocol 
solely by a computer using automated/algorithmic methods, such as natural language 
processing.
In these data sources, individual patient data are not retrieved or validated, and it is not 
possible to link (ie, identify a potential association between) a particular product and medical 
event for any individual. Thus, the minimum criteria for reporting an adverse event (AE) (ie, 
identifiable patient, identifiable reporter, a suspect product, and event) cannot be met.
Therefore, investigators and real world data vendors do not have any AE reporting 
requirements related to any medical information obtained as part of additional research using 
real world data (secondary data).
10.10.2. China
Retained research samples in Section 8.6.2 and Section 8.7.5 will not be collected in China. 
Biological samples leftover after analysis will be destroyed at a designated center in China. 
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10.10.3. United Kingdom
WOCBP enrolled in the United Kingdom will undergo a serum or whole blood pregnancy 
test at the screening visit to confirm negative pregnancy prior to first dose. A urine pregnancy 
test will be used for screening in other countries.
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Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 1 2 9
1 0. 1 1. A p pe n di x 1 1: A b bre vi ati o ns
T he f oll o wi n g is a list of a b bre viati o ns t hat ma y  be use d i n t he pr ot oc ol. 
A b bre vi ati o n
Ter m
% C V
perce nt c oefficie nt of variati o n
A 1 t o A 3
al b u mi n uria ( K DI G O al b u mi n uria se verit y sta n dar dizati o n)
A bs
a bs ol ute
A C R
al b u mi n-t o-creati ni ne rati o
A E
a d verse e ve nt
A KI
ac ute ki d ne y i nj ur y
A L T
ala ni ne a mi n otra nsferase
A RI
ac ute res pirat or y i nfecti o n
A S T
as partate a mi n otra nsferase
A U C
area u n der t he c o nce ntrati o n -ti me c ur ve
A U C 1 2
area u n der t he c o nce ntrati o n -ti me c ur ve fr o m ti me zer o t o 1 2 h o urs
A U C i nf
area u n der t he ser u m c o nce ntrati o n -ti me pr ofile fr o m ti me zer o 
e xtra p olate d t o i nfi nite ti me
A U C ta u
area u n der plas ma c o nce ntrati o n ti me c ur ve o ver d osi n g i nter val
A V
atri o ve ntric ular
A x M P
a u xiliar y me dici nal pr o d uct
-h C G
-h u ma n c h ori o nic g o na d otr o pi n
B P
bl o o d press ure
b p m
beats per mi n ute
C A R -T
c hi meric a nti ge n rece pt or T -cell
C D
cl uster of differe ntiati o n 
C F
c ystic fi br osis
C F R
C o de of Fe deral Re g ulati o ns
CI
c o nfi de nce i nter val
CI O M S
C o u ncil f or I nter nati o nal Or ga nizati o ns of Me dical Scie nces
C K
creati ne ki nase
C K D -E PI
c hr o nic ki d ne y disease e pi de mi ol o g y 
C L
cleara nce
C L / F
oral cleara nce
C ma x
ma xi m u m o bser ve d c o nce ntrati o n
C mi n
mi ni m u m c o nce ntrati o n
C tr o u g h S S
tr o u g h ( pre-d ose) c o nce ntrati o n at stea d y  state
C O N S O R T
C o ns oli date d Sta n dar ds of Re p orti n g Trials
C O P D
c hr o nic o bstr ucti ve p ul m o nar y  disease
C O VI D -1 9
c or o na vir us disease 2 0 1 9
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 1 3 0
A b bre vi ati o n
Ter m
C P A P
c o nti n u o us p ositi ve air wa y press ure
C -Q T
c o nce ntrati o n Q T a nal ys is
C R F
case re p ort f or m
C R O
c o ntract researc h or ga nizati o n
C S R
Cli nical St u d y  Re p ort
C T
c o m p ute d t o m o gra p h y/ cli nical trial
C TI S
Cli nical Trial I nf or mati o n S y ste m
C V
c halle n ge vir us
D AI D S
Di visi o n of Ac q uire d I m m u n o deficie nc y  Sy n dr o me
D C T
data c ollecti o n t o ol
D DI
dr u g -dr u g i nteracti o n 
DI CI
dr u g -i n d uce d creati ni ne i ncrease
DI KI
dr u g -i n d uce d ki d ne y i nj ur y
DI LI
dr u g -i n d uce d li ver i nj ur y
D N A
de o x yri b o n ucleic aci d
D P B
dr y  p o w der ble n d
D U
dis pe nsa ble u nit
E C
et hics c o m mittee; e xcl usi o n criteri o n
E C 9 0
9 0 % ma xi mal effecti ve c o nce ntrati o n
E C G
electr ocar di o gra m or electr ocar di o gra p h y
e Cr Cl
esti mate d creati ni ne cleara nce
E C M O
e xtrac or p oreal me m bra ne o x y ge nati o n
e C R F
electr o nic case re p ort f or m
E D
e mer ge nc y de part me nt
E D B
e x p os ure d uri n g breastfee di n g
E -D M C
E xter nal Data M o nit ori n g C o m mittee
E D P
e x p os ure d uri n g pre g na nc y
e G F R
esti mate d gl o mer ular filtrati o n rate
eIC D
electr o nic i nf or me d c o nse nt d oc u me nt
E Q - 5 D-5 L
a sta n dar dize d, vali date d, ge neric healt h relate d q ualit y  of life 
q uesti o n naire use d i n cli nical a n d ec o n o mic H T A e val uati o ns 
e x pa n de d t o a 5 le vel scale
e S A E
electr o nic seri o us a d verse e ve nt
E U
E ur o pea n U ni o n
E u dra C T
E ur o pea n U ni o n Dr u g Re g ulati n g A ut h orities Cli nical Trials 
( E ur o pea n Cli nical Trials Data base)
F A S
f ull a nal ysis set
F S H
f ollicle-sti m ulati n g h or m o ne
F/ U
f oll o w-u p
G C P
G o o d Cli nical Practice
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 1 3 1
A b bre vi ati o n
Ter m
G G T
ga m ma -gl uta m y l tra nsferase
GI
gastr oi ntesti nal
H 2
hista mi ne 2 rece pt or
H 0 P
n ull h y p ot hesis f or pri mar y  e n d p oi nt
H 0 S
n ull h y p ot hesis f or ke y  sec o n dar y e n d p oi nt
H b
he m o gl o bi n
H C P
healt h care pr ofessi o nal
HI V
h u ma n i m m u n o deficie nc y vir us
H R
heart rate
H R T
h or m o ne re place me nt t hera py
H T A
healt h tec h n ol o g y  assess me nt
I A
i nteri m a nal ysis
I B
I n vesti gat or’s Br oc h ure
I C D
i nf or me d c o nse nt d oc u me nt
I C H
I nter nati o nal C o u ncil f or Har m o nisati o n of Tec h nical Re q uire me nts 
f or P har mace uticals f or H u ma n Use
I C U
i nte nsi ve care u nit
I D
i de ntificati o n
I M P
i n vesti gati o nal me dici nal pr o d uct
I ND
I n vesti gati o nal Ne w Dr u g
I N R
i nter nati o nal n or malize d rati o
I P A L
I n vesti gati o nal Pr o d uct Acc o u nta bilit y L o g
I P M
i n vesti gati o nal pr o d uct ma n ual
I RB
I nstit uti o nal Re vie w B oar d
I R T
I nteracti ve Res p o nse Tec h n ol o g y
K DI G O
Ki d ne y  Disease: Im pr o vi n g Gl o bal O utc o mes
K D O QI
Ki d ne y  disease o utc o mes q ualit y i nitiati ve
L B B B
left b u n dle bra nc h bl oc k
L F T
li ver f u ncti o n test
L R TI
l o wer res pirat or y tract i nfecti o n
M A D
m ulti ple asce n di n g d ose
M C H
mea n c or p usc ular he m o gl o bi n
M C H C
mea n c or p usc ular he m o gl o bi n c o nce ntrati o n
M C V
mea n c or p usc ular v ol u me
mI T T
m o difie d i nte nt t o treat
M M R M
mi xe d m o del re peate d meas ures
M N
Mi etti ne n-N ur mi ne n
M QI
me dicall y  q ualifie d i n di vi d ual
N A
n ot a p plica ble
NI M P
n o ni n vesti gati o nal me dici nal pr o d uct
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI
C CI

Sis u nat o vir ( P F -0 7 9 2 3 5 6 8)
Pr ot oc ol C 5 2 4 1 0 0 7
Fi nal Pr ot oc ol A me n d me nt 1, 3 0 A pril 2 0 2 4
P FI Z E R C O N FI D E N TI A L
C T 0 2 -G S O P Cli nical Pr ot oc ol Te m plate P hase 1 2 3 4 ( 1 4 A pril 2 0 2 3)
Pa ge 1 3 2
A b bre vi ati o n
Ter m
N O A E L
n o o bser ve d a d verse effect le vel
N P
nas o p har y n geal
ns L R TI -R S V
R S V -relate d n o n-se vere l o wer res pirat or y tract i nfecti o n
N TI
narr o w t hera pe utic i n de x
N Y H A
Ne w Y or k Heart Ass ociati o n
P A H
p ul m o nar y  arterial h yperte nsi o n
P C R
p ol y merase c hai n reacti o n
P F
p ul m o nar y  fi br osis
P -g p
P -gl yc o pr otei n
P K
p har mac o ki netic(s)
P O
Oral(l y)
P R
p ulse rate
P R O
patie nt re p orte d o utc o me
P S S A
Pfizer's Seri o us A E S u b missi o n Assista nt
P T
pr ot hr o m bi n ti me
P V C
pre mat ure ve ntric ular c o ntracti o n
q 1 2 h
e ver y 1 2 h o urs
Q S P 
Q ua ntitati ve S y ste ms P har mac ol o g y
Q Tc
c orrecte d Q T i nter val
Q Tc F
Q Tc c orrecte d usi n g Fri dericia’s f or m ula
Q T L
q ualit y  t olera nce li mit
R B C
re d bl o o d cell
R ac
acc u m ulati o n rati o base d o n A U C ( o bser ve d)
R N A
ri b o n ucleic aci d
R S V
res pirat or y sy n c ytial vir us
R T -P C R
re verse tra nscri ptase P C R
S A D
si n gle asce n di n g d ose
S A E
seri o us a d verse e ve nt
S A P
Statistical A nal y sis Pla n
S A R S -C o V -2
se vere ac ute res pirat or y s yn dr o me c or o na vir us 2
Screat
ser u m creati ni ne
Sc y s
ser u m c ystati n C
s LR TI -R S V
R S V -relate d se vere l o wer res pirat or y tract i nfecti o n
S o A
sc he d ule of acti vities
S O P
sta n dar d o perati n g pr oce d ure
S R S D
Si n gle Refere nce Safet y D oc u me nt
S U S A R
S us pecte d U ne x pecte d Seri o us A d verse Reacti o n
t1/ 2
half life
T bili
t otal bilir u bi n
T E A E
treat me nt e mer ge nt a d verse e ve nt
T ma x
ti me ta ke n f or dr u g t o reac h C ma x after a d mi nistrati o n
0 9 0 1 7 7 e 1 a 0 8f 5 a b 3\ A p pr o v e d\ A p pr o v e d O n: 3 0- A pr- 2 0 2 4 1 7: 1 2 ( G M T)
C CI

Sisunatovir (PF-07923568)
Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 133
Abbreviation
Term
TNF
tumor necrosis factor
UACR
urine albumin/creatinine ratio
ULN
upper limit of normal
US
United States
VAS
visual analogue scale
WBC
white blood cell
WOCBP
woman/women of childbearing potential
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 134
11. REFERENCES
1.
Walsh EE, Falsey AR. Respiratory syncytial virus infection in adult populations. 
Infect Disord Drug Targets. 2012;12(2):98-102.
2.
Afonso CL, Amarasinghe GK, Banyai K, et al. Taxonomy of the order 
Mononegavirales: update 2016. Arch Virol. 2016;161(8):2351-60.
3.
Rima B, Collins P, Easton A, et al. ICTV Virus Taxonomy Profile: Pneumoviridae. J 
Gen Virol. 2017;98(12):2912-13.
4.
Chanock R, Finberg L. Recovery from infants with respiratory illness of a virus 
related to chimpanzee coryza agent (CCA). II. Epidemiologic aspects of infection in 
infants and young children. Am J Hyg. 1957;66(3):291-300.
5.
Nair H, Nokes DJ, Gessner BD, et al. Global burden of acute lower respiratory 
infections due to respiratory syncytial virus in young children: a systematic review 
and meta-analysis. Lancet. 2010;375(9725):1545-55.
6.
Jansen AG, Sanders EA, Hoes AW, et al. Influenza- and respiratory syncytial virus-
associated mortality and hospitalisations. Eur Respir J. 2007;30(6):1158-66.
7.
Falsey AR, Hennessey PA, Formica MA, et al. Respiratory syncytial virus infection 
in elderly and high-risk adults. N Engl J Med. 2005;352(17):1749-59.
8.
Shi T, Denouel A, Tietjen AK, et al. Global Disease Burden Estimates of Respiratory 
Syncytial Virus-Associated Acute Respiratory Infection in Older Adults in 2015: A 
Systematic Review and Meta-Analysis. J Infect Dis. 2020;222(Suppl 7):S577-S83.
9.
Taleb SA, Al Thani AA, Al Ansari K, et al. Human respiratory syncytial virus: 
pathogenesis, immune responses, and current vaccine approaches. Eur J Clin 
Microbiol Infect Dis. 2018;37(10):1817-27.
10.
Jha A, Jarvis H, Fraser C, et al. Respiratory Syncytial Virus. In: SARS, MERS and 
other Viral Lung Infections. Wellcome Trust-Funded Monographs and Book 
Chapters. Hui DS, Rossi GA, Johnston SL, eds. Sheffield (UK):2016.
11.
Kim L, Rha B, Abramson JS, et al. Identifying Gaps in Respiratory Syncytial Virus 
Disease Epidemiology in the United States Prior to the Introduction of Vaccines. Clin 
Infect Dis. 2017;65(6):1020-25.
12.
Nilsson AC, Pullman J, Napora P, et al. A pilot phase 2a, randomized, double-blind, 
placebo-controlled study to explore the antiviral activity, clinical outcomes, safety, 
and tolerability of rilematovir at two dose levels in non-hospitalized adults with 
respiratory syncytial virus infection. Clin Microbiol Infect. 
2023;10.1016/j.cmi.2023.07.004.
13.
Chemaly RF, Dadwal SS, Bergeron A, et al. A Phase 2, Randomized, Double-blind, 
Placebo-Controlled Trial of Presatovir for the Treatment of Respiratory Syncytial 
Virus Upper Respiratory Tract Infection in Hematopoietic-Cell Transplant 
Recipients. Clin Infect Dis. 2020;71(11):2777-86.
14.
Papi A, Ison MG, Langley JM, et al. Respiratory Syncytial Virus Prefusion F Protein 
Vaccine in Older Adults. N Engl J Med. 2023;388(7):595-608.
15.
Agborsangaya CB, Lahtinen M, Cooke T, et al. Comparing the EQ-5D 3L and 5L: 
measurement properties and association with chronic conditions and multimorbidity 
in the general population. Health Qual Life Outcomes. 2014;12:74.
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Protocol C5241007
Final Protocol Amendment 1, 30 April 2024
PFIZER CONFIDENTIAL
CT02-GSOP Clinical Protocol Template Phase 1 2 3 4 (14 April 2023)
Page 135
16.
Herdman M, Gudex C, Lloyd A, et al. Development and preliminary testing of the 
new five-level version of EQ-5D (EQ-5D-5L). Qual Life Res. 2011;20(10):1727-36.
17.
Janssen MF, Pickard AS, Golicki D, et al. Measurement properties of the EQ-5D-5L 
compared to the EQ-5D-3L across eight patient groups: a multi-country study. Qual 
Life Res. 2013;22(7):1717-27.
18.
Rabin R, Gudex C, Selai C, et al. From translation to version management: a history 
and review of methods for the cultural adaptation of the EuroQol five-dimensional 
questionnaire. Value Health. 2014;17(1):70-6.
19.
Ramos-Goni JM, Pinto-Prades JL, Oppe M, et al. Valuation and Modeling of EQ-5D-
5L Health States Using a Hybrid Approach. Med Care. 2017;55(7):e51-e58.
20.
van Hout B, Janssen MF, Feng YS, et al. Interim scoring for the EQ-5D-5L: mapping 
the EQ-5D-5L to EQ-5D-3L value sets. Value Health. 2012;15(5):708-15.
21.
National Institute of Allergy and Infectious Diseases NIoH. Division of AIDS 
(DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events 
Corrected Version 2.1. Jul 2017. Available from: 
https://rsc.niaid.nih.gov/sites/default/files/daidsgradingcorrectedv21.pdf. Accessed: 
10 Jun 2021.
22.
Glimm E, Maurer W, Bretz F. Hierarchical testing of multiple endpoints in group-
sequential trials. Stat Med. 2010;29(2):219-28.
23.
Miettinen O, Nurminen M. Comparative analysis of two rates. Stat Med. 
1985;4(2):213-26.
24.
Austin PC, White IR, Lee DS, et al. Missing Data in Clinical Research: A Tutorial on 
Multiple Imputation. Can J Cardiol. 2021;37(9):1322-31.
25.
Hwang IK, Shih WJ, De Cani JS. Group sequential designs using a family of type I 
error probability spending functions. Stat Med. 1990;9(12):1439-45.
26.
Mehta CR, Pocock SJ. Adaptive increase in sample size when interim results are 
promising: a practical guide with examples. Stat Med. 2011;30(28):3267-84.
27.
Cui L, Hung HM, Wang SJ. Modification of sample size in group sequential clinical 
trials. Biometrics. 1999;55(3):853-7.
28.
FDA. Adaptive Designs for Clinical Trials of Drugs and Biologics - Guidance for 
Industry. Nov 2019. Available from: https://www.fda.gov/media/78495/download.
29.
Lan KKG, Demets DL. Discrete Sequential Boundaries for Clinical-Trials. 
Biometrika. 1983;70(3):659-63.
30.
Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C-Based 
Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-49.
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