A Phase 1, Single Center, Open-label Study of PF-07321332 Administrated as Multiple Oral Doses in Healthy Chinese Participants.
Phase: PHASE1
Conditions: Healthy Participants
Sponsor: Pfizer

PF-07321332
Protocol C4671016
Final Protocol, 27 September 2021 
PFIZER CONFIDENTIAL
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A PHASE 1, SINGLE CENTER, OPEN-LABEL STUDY OF PF-07321332 
ADMINISTERED IN COMBINATION WITH RITONAVIR AS REPEATED DOSES 
IN HEALTHY CHINESE PARTICIPANTS
Study Intervention Number:
PF-07321332
Study Intervention Name:
N/A
US IND Number:
N/A
EudraCT Number:
N/A
ClinicalTrials.gov ID: 
N/A
Protocol Number:
C4671016
Phase:
1
Brief Title: A Phase 1 Study of PF-07321332 Co-Administered With Ritonavir in 
Healthy Chinese Participants
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.

PF-07321332
Protocol C4671016
Final Protocol, 27 September 2021 
PFIZER CONFIDENTIAL
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Document History
Document
Version Date
Original protocol
27 September 2021

PF-07321332
Protocol C4671016
Final Protocol, 27 September 2021 
PFIZER CONFIDENTIAL
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TABLE OF CONTENTS
LIST OF TABLES.....................................................................................................................7
1. PROTOCOL SUMMARY.....................................................................................................8
1.1. Synopsis ....................................................................................................................8
1.2. Schema ....................................................................................................................10
1.3. Schedule of Activities .............................................................................................11
2. INTRODUCTION ...............................................................................................................14
2.1. Study Rationale .......................................................................................................14
2.2. Background .............................................................................................................14
2.2.1. Nonclinical Pharmacology..........................................................................15
2.2.2. Nonclinical Pharmacokinetics and Metabolism .........................................15
2.2.3. Nonclinical Safety ......................................................................................15
2.2.4. Clinical Overview.......................................................................................16
2.2.4.1. Safety Overview........................................................................16
2.2.4.2. Summary of PF-07321332 Pharmacokinetics in Human..........17
2.3. Benefit/Risk Assessment.........................................................................................17
2.3.1. Risk Assessment.........................................................................................19
2.3.2. Benefit Assessment.....................................................................................21
2.3.3. Overall Benefit/Risk Conclusion................................................................21
3. OBJECTIVES AND ENDPOINTS.....................................................................................21
4. STUDY DESIGN.................................................................................................................21
4.1. Overall Design.........................................................................................................21
4.2. Scientific Rationale for Study Design.....................................................................22
4.2.1. Choice of Contraception/Barrier Requirements .........................................23
4.3. Justification for Dose ..............................................................................................23
4.4. End of Study Definition ..........................................................................................23
5. STUDY POPULATION......................................................................................................24
5.1. Inclusion Criteria.....................................................................................................24
5.2. Exclusion Criteria....................................................................................................25
5.3. Lifestyle Considerations..........................................................................................28
5.3.1. Meals and Dietary Restrictions...................................................................28

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5.3.2. Caffeine, Alcohol, and Tobacco .................................................................28
5.3.3. Activity .......................................................................................................28
5.3.4. Contraception..............................................................................................29
5.4. Screen Failures ........................................................................................................29
6. STUDY INTERVENTION(S) AND CONCOMITANT THERAPY.................................29
6.1. Study Intervention(s) Administered........................................................................29
6.1.1. Administration............................................................................................29
6.2. Preparation, Handling, Storage, and Accountability...............................................30
6.2.1. Preparation and Dispensing........................................................................31
6.3. Measures to Minimize Bias: Randomization and Blinding.....................................31
6.3.1. Allocation to Study Intervention ................................................................31
6.4. Study Intervention Compliance...............................................................................32
6.5. Dose Modification...................................................................................................32
6.6. Continued Access to Study Intervention After the End of the Study......................32
6.7. Treatment of Overdose............................................................................................32
6.8. Concomitant Therapy..............................................................................................33
6.8.1. Rescue Medicine.........................................................................................33
7. DISCONTINUATION OF STUDY INTERVENTION AND PARTICIPANT 
DISCONTINUATION/WITHDRAWAL...........................................................................33
7.1. Discontinuation of Study Intervention ....................................................................33
7.1.1. ECG Changes..............................................................................................34
7.1.2. Potential Cases of Acute Kidney Injury .....................................................34
7.1.3. Stopping Rules............................................................................................35
7.2. Participant Discontinuation/Withdrawal From the Study.......................................35
7.2.1. Withdrawal of Consent...............................................................................36
7.3. Lost to Follow up ....................................................................................................36
8. STUDY ASSESSMENTS AND PROCEDURES...............................................................36
8.1. Efficacy Assessments..............................................................................................38
8.2. Safety Assessments .................................................................................................38
8.2.1. Physical Examinations................................................................................38
8.2.2. Vital Signs ..................................................................................................38
8.2.2.1. Respiratory Rate........................................................................39

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8.2.2.2. Temperature ..............................................................................39
8.2.3. Electrocardiograms.....................................................................................39
8.2.4. Clinical Safety Laboratory Assessments ....................................................40
8.2.5. COVID-19 Specific Assessments...............................................................40
8.2.6. Pregnancy Testing ......................................................................................40
8.2.7. Thyroid Ultrasound.....................................................................................41
8.3. Adverse Events, Serious Adverse Events, and Other Safety Reporting .................41
8.3.1. Time Period and Frequency for Collecting AE and SAE Information.......41
8.3.1.1. Reporting SAEs to Pfizer Safety...............................................42
8.3.1.2. Recording Nonserious AEs and SAEs on the CRF...................42
8.3.2. Method of Detecting AEs and SAEs ..........................................................42
8.3.3. Follow-Up of AEs and SAEs......................................................................42
8.3.4. Regulatory Reporting Requirements for SAEs...........................................43
8.3.5. Environmental Exposure, Exposure During Pregnancy or 
Breastfeeding, and Occupational Exposure.....................................................43
8.3.5.1. Exposure During Pregnancy......................................................43
8.3.5.2. Exposure During Breastfeeding ................................................45
8.3.5.3. Occupational Exposure .............................................................45
8.3.6. Cardiovascular and Death Events...............................................................46
8.3.7. Disease-Related Events and/or Disease-Related Outcomes Not 
Qualifying as AEs or SAEs..............................................................................46
8.3.8. Adverse Events of Special Interest.............................................................46
8.3.8.1. Lack of Efficacy........................................................................46
8.3.9. Medical Device Deficiencies......................................................................46
8.3.10. Medication Errors.....................................................................................46
8.4. Pharmacokinetics ....................................................................................................47
8.4.1. Plasma Pharmacokinetics ...........................................................................47
8.5. Genetics...................................................................................................................48
8.5.1. Specified Genetics ......................................................................................48
8.5.2. Retained Research Samples for Genetics ...................................................49
8.6. Biomarkers ..............................................................................................................49
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8.6.1. Specified Gene Expression (RNA) Research .............................................49
8.6.2. Specified Protein Research.........................................................................49
8.6.3. Specified Metabolomic Research ...............................................................49
8.6.4. Retained Research Samples for Biomarkers...............................................49
8.7. Immunogenicity Assessments.................................................................................49
8.8. Health Economics ...................................................................................................49
9. STATISTICAL CONSIDERATIONS ................................................................................49
9.1. Statistical Hypotheses .............................................................................................49
9.2. Analysis Sets ...........................................................................................................50
9.3. Statistical Analyses .................................................................................................50
9.3.1. Statistical Methods for Pharmacokinetic data ............................................50
9.3.2. Derivation of Pharmacokinetic Parameters Prior to Analysis ....................51
9.3.3. Safety Analyses ..........................................................................................52
9.4. Interim Analyses .....................................................................................................53
9.5. Sample Size Determination.....................................................................................53
10. SUPPORTING DOCUMENTATION AND OPERATIONAL 
CONSIDERATIONS..........................................................................................................54
10.1. Appendix 1: Regulatory, Ethical, and Study Oversight Considerations...............54
10.1.1. Regulatory and Ethical Considerations ....................................................54
10.1.1.1. Reporting of Safety Issues and Serious Breaches of the 
Protocol or ICH GCP.........................................................................54
10.1.2. Informed Consent Process ........................................................................55
10.1.3. Data Protection .........................................................................................55
10.1.4. Committees Structure ...............................................................................56
10.1.4.1. Data Monitoring Committee ...................................................56
10.1.5. Dissemination of Clinical Study Data ......................................................56
10.1.6. Data Quality Assurance ............................................................................57
10.1.7. Source Documents....................................................................................58
10.1.8. Study and Site Start and Closure ..............................................................59
10.1.9. Publication Policy.....................................................................................60
10.1.10. Sponsor’s Qualified Medical Personnel .................................................60
10.2. Appendix 2: Clinical Laboratory Tests .................................................................62

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10.3. Appendix 3: Adverse Events: Definitions and Procedures for Recording, 
Evaluating, Follow-Up, and Reporting .....................................................................63
10.3.1. Definition of AE .......................................................................................63
10.3.2. Definition of an SAE ................................................................................64
10.3.3. Recording/Reporting and Follow-Up of AEs and/or SAEs During 
the Active Collection Period............................................................................65
10.3.4. Reporting of SAEs....................................................................................69
10.4. Appendix 4: Contraceptive and Barrier Guidance ................................................70
10.4.1. Male Participant Reproductive Inclusion Criteria....................................70
10.4.2. Female Participant Reproductive Inclusion Criteria.................................70
10.4.3. Woman of Childbearing Potential ............................................................71
10.4.4. Contraception Methods.............................................................................72
10.5. Appendix 5: Liver Safety: Suggested Actions and Follow-Up Assessments .......73
10.6. Appendix 6: ECG Findings of Potential Clinical Concern ...................................75
10.7. Appendix 7: Abbreviations ...................................................................................77
11. REFERENCES ..................................................................................................................81
LIST OF TABLES
Table 1.
Plasma 
 PK Parameters.............................................................51
Table 2.
Protocol-Required Safety Laboratory Assessments .................................62
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1. PROTOCOL SUMMARY 
1.1. Synopsis 
Brief Title: A Phase 1 Study of PF-07321332 Co-Administered With Ritonavir in Healthy 
Chinese Participants
Rationale
The purpose of the study is to investigate the PK, safety and tolerability of PF-07321332 
following repeated oral doses in combination with a PK boosting agent ritonavir in Chinese 
healthy adults. One (or more) suitable Western study(ies) will be selected for comparison 
between Western and Chinese populations. This may involve comparison of Day 1 data 
and/or steady-state data 
 with the data obtained from the 
Chinese Phase 1 study and Western populations. 
 
Objectives and Endpoints
Objectives
Endpoints
Primary: 
Primary: 
•
To characterize the plasma PK of PF-07321332 
when PF-07321332/ritonavir is administered in 
healthy Chinese participants
•
PF-07321332 plasma PK parameters:
•
Day 1: Cmax, Tmax, AUC12
•
Day 5, 8,10 (pre-dose and 12 hours after last 
dose): Ctrough
•
Day 10: Cmax, Tmax, AUCtau; and if data 
permit, AUClast, Cav, Rac, Rac,Cmax, PTR, 
CL/F, Vz/F and t½
Secondary: 
Secondary: 
•
To determine the safety and tolerability of 
PF-07321332/ritonavir in healthy Chinese 
participants after dose administration
•
To characterize the plasma PK of ritonavir 
following PF-07321332/ritonavir
administration in healthy Chinese participants
•
AEs, clinical safety laboratory tests, vital signs, 
12-lead ECGs
•
Ritonavir plasma PK parameters:
•
Day 1: Cmax, Tmax, AUC12
•
Day 5, 8,10 (pre-dose and 12 hours after last 
dose): Ctrough
•
Day 10: Cmax, Tmax, AUCtau; and if data 
permit, AUClast, Cav, CL/F, Vz/F and t½
 
 
 
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Final Protocol, 27 September 2021 
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Overall Design
Brief Summary
This is a Phase 1, open-label study to estimate the PK, safety and tolerability of PF-07321332 
when PF-07321332/ritonavir is administered in healthy Chinese participants. The study will 
consist of 1 treatment: multiple oral doses of 300 mg PF-07321332/100 mg ritonavir. A total 
of approximately 14 healthy male and/or female participants will be enrolled into the study to 
ensure at least 12 participants will complete the study. Participants who discontinue from the 
study for non-safety reasons may be replaced at the sponsor’s discretion in collaboration with 
the Investigator.
The total duration of participation in this study is approximately 73 days, including a 
screening period of up to 28 days to confirm eligibility, treatment duration about 12 days 
(10 days of dose duration and another 2 days of full PK profile duration) and a follow-up 
period of approximately 28-35 days post the last dose of study intervention. 
Participants will be admitted to the CRU on Day -1 and may be discharged at the discretion 
of the investigator following completion of assessments per protocol requirement on Day 12
(2 days after last dose on Day 10).
All of participants will receive PF-07321332 and ritonavir together. The dose regimen is 
PF-07321332/ritonavir 300/100 mg q12h for a total of 19 oral doses (Day 1 to Day 10). The 
first dose and the last dose will be recommended to be administrated on Day 1 and Day 10 
morning, respectively, for intensive PK sample collection. 
Following discharge on Day 12 after last PK and safety assessment, follow-up contact may 
occur via telephone and must occur within 28 to 35 days after the last dose of investigational 
product, or via on-site visit if it is necessary per investigator’s evaluation. Participants who 
prematurely discontinue for non-safety related reasons may be replaced, at the discretion of 
the principal investigator and sponsor study team.
Number of Participants
Approximately 14 participants will be enrolled to study intervention.
Note: "Enrolled" means a participant's, or his or her legally authorized representative’s, 
agreement to participate in a clinical study following completion of the informed consent 
process and screening. A participant will be considered enrolled if the informed consent is 
not withdrawn prior to participating in any study activity after screening. Potential 
participants who are screened for the purpose of determining eligibility for the study, but do 
not participate in the study, are not considered enrolled, unless otherwise specified by the 
protocol.

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Final Protocol, 27 September 2021 
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Intervention Groups and Duration
All of participants will receive PF-07321332 and ritonavir together. The dose regimen is 
PF-07321332/ritonavir 300/100 mg q12h for a total of 19 oral doses (Day 1 to Day 10). The 
first dose and the last dose will be recommended to be administrated on Day 1 and Day 10 
morning, respectively, for intensive PK sample collection feasibility. 
Participants may be discharged on Day 12 following completion of PK sampling. 
The total duration of participation in this study is approximately 73 days, including a 
screening period of up to 28 days to confirm eligibility, treatment duration about 12 days 
(10 days of dose duration and another 2 days of full PK profile duration) and a follow-up 
period of approximately 28-35 days post the last dose of study intervention. 
Data Monitoring Committee or Other Independent Oversight Committee: No
Statistical Methods
All data analyses will be descriptive.
PF-07321332 and ritonavir PK parameters will be listed and summarized descriptively for 
single dose (Day 1) and repeated dose (Day 5, 8, 10). For AUCs and Cmax, box whisker plots 
will be plotted for each analyte. For pre-dose concentration, plot of Ctrough over time will be 
provided for each analyte. The concentrations of PF-07321332 and ritonavir will be listed 
and descriptively summarized by study day and nominal PK sampling times. For each 
analyte, individual participant and summary profiles (mean and median plots) of the plasma 
concentration time data will be plotted using actual and nominal sampling times, 
respectively.
Safety data (AEs, vital signs, ECGs, laboratory data etc.) will be presented in tabular and/or 
graphical format and summarized descriptively, where appropriate. 
1.2. Schema
Screening
Treatment
Follow-Up
Day -28 to Day -2
Day -1 to Day 12
Day 28-35*
Screening Eligibility
Combined Use
PF-07321332/Ritonavir, 300 mg/100 mg, BID 
(10 days, totally 19 doses)
(10 days of dose duration and another 2 days of full PK 
profile duration)
* 28 to 35 days after last dose.

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1.3. Schedule of Activities
The SoA table provides an overview of the protocol visits and procedures. Refer to the STUDY ASSESSMENTS AND 
PROCEDURES section of the protocol for detailed information on each procedure and assessment required for compliance with the 
protocol. 
The investigator may schedule visits (unplanned visits) in addition to those listed in the SoA table, in order to conduct evaluations or 
assessments required to protect the well-being of the participant.
Visit Identifiera
Abbreviations used in this table may be found 
in Appendix 7.
Screening
Treatment
Follow-Up 
Early 
Termination/
Discontinuation
Days Relative to Day 1
Day -28 
to Day -2
Day -1 Day 
1
Day 
2
Day 
3
Day
4
Day 
5
Day 
6
Day 
7
Day 8 Day 9 Day 10 Day 
11
Day
12
28-35 
Daysb
Informed consent
X
CRU confinementc
X
→
→
→
→ 
→
→
→ 
→
→
→
→
Inclusion/exclusion criteria
X
X
Medical/medication history (update)d
X
X
Physical exam (including height, body weight
and BMI at Screening only)e
X
X
X
X
Safety laboratoryf
X
X
X
X
X
X
X
X
TSH and free T4g
X
X
X
X
Thyroid ultrasound and antibody (aTPO, 
ATG) testsg
X
X
Demography
X
Pregnancy test (WOCBP only)
X
X
X
X
Contraception check (Inquiry)h
X
X
X
X
X
FSHi
X
Urine drug testingj
X
X
12-Lead ECG (triplicate)k
X
X
X
X
Vital signs (BP/PR/RR/temperature)k
X
X
X
X
Serology: HIV, HBsAg, HCVAb, HBcAb
X
COVID-19 questionnairel
X
X
COVID-19 testingm
Xn
Xn
COVID-19 check temperatureo
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Study intervention administrationp
X
X
X
X
X
X
X
X
X
X
PK blood samplingq
X
X
X
X
X
X
X
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Visit Identifiera
Abbreviations used in this table may be found 
in Appendix 7.
Screening
Treatment
Follow-Up 
Early 
Termination/
Discontinuation
Days Relative to Day 1
Day -28 
to Day -2
Day -1 Day 
1
Day 
2
Day 
3
Day
4
Day 
5
Day 
6
Day 
7
Day 8 Day 9 Day 10 Day 
11
Day
12
28-35 
Daysb
CRU dischargec
X
Serious and nonserious AE monitoring and
follow-up
X
→
→
→
→
→ 
→
→
→ 
→
→
→
→
→
→
X
a.
Day relative to start of study intervention (Day 1).
b.
Contact may occur via telephone contact and must occur 28 to 35 days from administration of the final dose of study intervention.
c.
Participants will be admitted to the CRU on Day -1 and may be discharged on Day 12, following completion of all PK and safety assessment required by protocol, at the 
investigator’s discretion.
d.
Medical history will include a history of prior illegal drug, alcohol, and tobacco use, as well as blood donation within prior 60 days. Medical history will be recorded at 
Screening and updated on Day -1.
e.
A complete PE will be performed by trained medical personnel at the investigator site at Screening or Day -1 only (height and weight must be obtained at Screening only to 
obtain BMI for eligibility criteria). A brief PE may be performed at other designated time points at the discretion of the investigator.
f.
Safety laboratory test: should be taken during screening period and Day-1, and should be taken pre-dose (within 30 min before administration) in the morning only during 
treatment period (Days 2, 5, 8, 10), and taken 48 (± 1 hour) hours after last dose of intervention administration on Day 12, with at least 4-hour fasting. Additional safety 
laboratory assessments may be performed at any time at the discretion of the investigator. Safety laboratory test includes hematology, chemistry, urinalysis and coagulation 
test (aPTT, PT, INR and fibrinogen).
g.
All thyroid related test should be collected at least once before dosing. Investigator may choose to either collect at screening or Day -1 or both. No fasting requirement for 
all TSH, free T4 and antibody (aTPO, ATG) testing. Other TSH, free T4, thyroid ultrasound and antibody (aTPO, ATG) tests are permitted to be conducted at any time of 
the investigator’s discretion. 
h.
The investigator will discuss with the participant the need to use highly effective contraception consistently and correctly according to contraception guidelines.
i.
For postmenopausal (amenorrheic for at least 12 consecutive months) female participants only.
j.
Urine drug test will be performed at Screening and on Day -1. This test may be performed at any other time at the discretion of the investigator. 
k.
Vital signs and 12-lead ECGs (triplicate) are collected during screening, Day 1, Day 10 or when early termination/discontinuation occurs. Refer to PK and ECG/Vital Signs 
Sampling Schedule below for detailed ECG/vital signs collection timepoint on Day 1 and Day 10. All ECG assessments (triplicate) and vital sign test will be made after at 
least a 5-minute rest in a supine position. The order is ECG assessment prior to vital sign measurements, and prior to any blood draws, if occurred on the same timepoint.
Additional 12-lead ECGs and vital signs assessments may be performed at any time at the discretion of the investigator.
l.
Check exposure to positive subject, residence or travel in area of high incidence and COVID-19 related signs and symptoms per local/site’s epidemic prevention
requirement. To be done at least 48 hours before and at admission on Day -1. Another COVID-19 questionnaire needs to be conducted if participants leave CRU and come 
back, or on site follow-up visit.
m.
The testing for COVID-19 pathogen by PCR (COVID-19 PCR testing) will be performed within at least 72 hours prior to admission on Day -1 (may be performed during 
screening or on Day -1). For participants admitted for residence, a subsequent COVID-19 test will be performed if they develop COVID-19 like symptoms.
n.
Additional COVID-19 testing (eg. COVID-19 PCR testing, CT, COVID-19 antibody, etc) at screening or Day -1 at investigator’s discretion may be permitted.
o.
To be done at least daily during the hospital stay in the clinical research unit. 
p.
PF-07321332/ritonavir will be administered orally, q12h for a total of 19 doses. PF-07321332 and ritonavir will be dosed simultaneously (within no more than 5 minutes of 
each other). Participants will receive randomization before dosing.
q.
Blood samples for PK analysis of PF-07321332 and ritonavir will be taken on each timepoint. Refer to PK and ECG/Vital Signs Sampling Schedule below for detailed PK
and ECG/vital signs sample timepoint.
 
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PK and ECG/Vital Signs Sampling Schedule
Visit Identifier 
Schedules for Days 1-9
Study Day
1
5, 8
Hours Post Morning Dose on That Day
0
0.5
1
1.5
2
4
6
8
12
0
Study intervention administration
X
X
X
PK blood sampling 
Xb
X
X
X
X
X
X
X
Xa
Xb
12-lead ECG (triplicate)d
X
 
→ 
→ 
→ 
 
 
 
Vital signs (BP/PR/RR/temperature)d
X
 
→ 
→ 
→ 
 
 
 
a.
PK blood sample should be collected within 10 min before the study intervention administration in the evening on Day 1.
b.
PK blood sample should be collected within 30 min before the study intervention administration in the morning on Day 1, Day 5 and Day 8.
 
d.
On Day 1, vital signs and 12-lead ECGs (triplicate) are to be collected pre-dose (within 2 hours before administration), and within 1 hour to 2 hours after administration in 
the morning. 
Visit Identifier 
Schedules for Days 10-12
Study Day
10
11-12
Hours Post Dose on Study Day 10
0
0.5
1
1.5
2
4
6
8
12
24
48
Study intervention administrationa
X
PK blood sampling 
Xb
X
X
X
X
X
X
X
X
X
X
12-Lead ECG (triplicate)d
X
 
→ 
→ 
→ 
 
 
 
Vital signs (BP/PR/RR/temperature)d
X
 
→ 
→ 
→ 
 
 
 
a.
The last dose will be administrated in the morning on Day 10, since no evening dose will be given on Day 10.
b.
PK blood sample should be collected within 30 min before the study intervention administration in the morning.
 
d.
On Day 10, vital signs and 12-lead ECGs (triplicate) are to be collected pre-dose (within 2 hours before administration), and within 1 hour to 2 hours after administration in 
the morning.
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2. INTRODUCTION
PF-07321332 is a potent and selective inhibitor of the SARS-CoV-2 3CL protease that is 
currently being developed as an oral treatment of COVID-19. Ritonavir is a strong CYP3A4 
inhibitor being used to inhibit the metabolism of PF-07321332 in order to increase plasma 
concentrations of PF-07321332 to values that are anticipated to be efficacious. 
2.1. Study Rationale 
The purpose of the study is to investigate the PK, safety and tolerability of PF-07321332 
following repeated oral doses in combination with a PK boosting agent ritonavir in Chinese 
healthy adults. 
All comparisons to Western participants will be conducted outside this protocol and the CSR. 
2.2. Background 
In December 2019, COVID-19 was identified as a new, potentially fatal, respiratory infection 
caused by the novel coronavirus, SARS-CoV-2. The WHO declared COVID-19 a Public 
Health Emergency of International Concern on 20 January 2020 and further characterized the 
disease outbreak as a pandemic on 11 March 2020.1
PF-07321332 is an orally bioavailable 3CLpro inhibitor shown to be effective against 
SARS-CoV-2 3CLpro (Ki = 0.00311 μM) in a biochemical enzymatic assay. Since the 3CLpro
from human coronaviruses are structurally similar and share a high degree of conservation at 
the active site of the enzyme, the ability of PF-07321332 to inhibit the 3CLpro of other 
coronaviruses (SARS-CoV-1 and HCoV-229E, MERS, HcoV-OC43, HcoV-HKU1, and 
HcoV-NL63) was also confirmed, indicating a potential for broad spectrum anti-coronavirus 
activity. The coronavirus 3CL protease is a virally encoded enzyme that is critical to the 
SARS-CoV-2 replication cycle, analogous to other obligatory virally encoded proteases (eg,
HIV Protease, HCV Protease).2 PF-07321332 is being developed as an oral treatment in 
patients with COVID-19 infection. 
Ritonavir is a strong CYP3A4 inhibitor being used to inhibit the metabolism of PF-07321332 
in order to increase plasma concentrations of PF-07321332 to values that are anticipated to 
be efficacious. Ritonavir is not expected to have any pharmacological impact on the 
SARS-CoV-2 virus and its elimination is not expected to be significantly altered by renal 
impairment. Ritonavir is being used only as a PK boosting agent.
In vitro and in vivo metabolite profiling suggests that the primary clearance mechanism for 
PF-07321332 is CYP3A4 mediated oxidation. In a reaction phenotyping study using human 
liver microsomes in the presence of selective CYP inhibitors, CYP3A4 was predicted to be 
the major contributor (fm = 0.99) to the in vitro oxidative metabolism of PF-07321332. As 
such, in the FIH Study, C4671001, the CYP3A4 inhibitor ritonavir was used to enhance the 
exposure of PF-07321332 in order to achieve plasma levels that are anticipated to be 
efficacious.
 
 
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 Ritonavir is 
extensively metabolized, primarily by CYP3A4.3
2.2.1. Nonclinical Pharmacology
Details of the nonclinical pharmacology of PF-07321332 can be found in the current IB.
2.2.2. Nonclinical Pharmacokinetics and Metabolism
Hepatic CYP3A enzymes were identified as the main pathway for clearance of PF-07321332 
in vitro in liver microsomes (mouse, rat, hamster, rabbit, monkey, and human), hepatocytes 
(rat, monkey, and human), and in vivo in rat and monkey after repeat oral dosing. In a 
reaction phenotyping study using human liver microsomes in the presence of selective CYP 
inhibitors, CYP3A4 was predicted to be the major contributor (fm = 0.99) to the in vitro 
oxidative metabolism of PF-07321332. No significant CYP3A5 contribution is expected to 
the metabolism of PF-07321332. Urinary excretion of PF-07321332 following single IV or 
oral doses in rats was approximately 11%, suggesting minor urinary contributions to the 
overall elimination of PF-07321332. 
PF-07321332 will be combine used with ritonavir (a CYP3A4 inhibitor) instead of 
monotherapy, 
 
Additional information of the nonclinical PK and metabolism of PF-07321332 is available in 
the current IB.
2.2.3. Nonclinical Safety
There were no adverse findings observed in repeat-dose toxicity studies in rats and monkeys 
up to two weeks duration and the NOAELs were the highest dose administered (1000 mg/kg 
and 600 mg/kg in the rat and monkey studies, respectively). PF-07321332
related non-adverse, test article-related clinical findings included sporadic occurrence of 
emesis with slight body weight decreases in monkeys. Monitorable and reversible clinical 
pathology findings included those possibly suggestive of low-grade inflammation (in rats and 
monkeys) or alterations in the coagulation pathways (in rats only) without clinical or 
microscopic correlates. Other non-adverse clinical pathology findings were likely due to the 
emesis and subsequent dehydration in monkeys. In rats administered 1000 mg/kg/day, lower 
mean absolute and relative heart weights (females) and higher absolute and relative liver 
weights (both sexes) were observed relative to controls. The lower heart weights had no 
microscopic correlates and were fully reversed at the end of the 2-week recovery period. 
Higher liver weights correlated with reversible, non-adverse microscopic findings of minimal 
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to mild severity in the liver and thyroid gland consistent with adaptive changes related to 
microsomal enzyme induction.

PF-07321332 was not mutagenic or clastogenic in in vitro genetic toxicity studies and 
was negative in the in vivo rat micronucleus assay incorporated into the GLP repeat-dose 
rat toxicity study. 

The nonclinical studies performed adequately support the oral administration of 
PF-07321332 in the clinic for up to 14 days. 
Further details of the nonclinical safety program are provided in the current IB.
2.2.4. Clinical Overview
Safety, tolerability and PK of PF-07321332 in healthy adult participants is currently being 
explored in an ongoing Phase 1 FIH Study (C4671001). It is a 5-part study combining 
PART-1: SAD, PART-2: MAD, PART-3: relative bioavailability/food effect, PART-4: M&E 
and PART-5: SE. PART-1 and 2 are randomized, double-blind, sponsor-open, 
placebo-controlled trial to evaluate safety, tolerability and PK of single and multiple 
escalating oral doses of PF-07321332 in healthy adult participants and PART-3 is a 
randomized open label study to evaluate relative bioavailability and food effect of an oral 
tablet formulation. PART-2 of the study may also evaluate the safety tolerability and PK in 
Japanese participants. PART-4 is an open-label, non-randomized, single period to evaluate 
the metabolism and excretion of PF-07321332. PART-5 is a double-blind, sponsor-open, 
randomized, cross-over study to evaluate safety and tolerability at supratherapeutic 
exposures.
2.2.4.1. Safety Overview
Preliminary safety and tolerability data from Study C4671001 as of 07 April 2021 in PART-1 
and 14 April 2021 in PART-2 (data snapshot taken) demonstrated PF-07321332 was 
generally safe and well-tolerated in healthy participants at single doses of PF-07321332 
ranging from 150 mg to 1500 mg alone and at 250 mg and 750 mg with ritonavir (100 mg at 
-12 h, 0 h, 12 h) in the PART-1: SAD, and 10 days of dosing from 75 mg q12h to 500 mg
q12h with 100 mg ritonavir q12h in the PART-2: MAD of the study. 
Following single doses of PF-07321332 with and without ritonavir, all AEs were mild and 
none were considered treatment related. There were no obvious trends in, or association of, 
TEAEs with dose level of PF-07321332. Following multiple doses, the most commonly 
observed AEs by system organ class were gastrointestinal disorders and nervous system 
disorders. Diarrhea was the most common reported AE, occurring in 4 participants across 
treatment groups. A total of 5 treatment related TEAEs were observed in Part-2: MAD. 
Across treatment groups, blood TSH increased in 3 participants, and 2 participants reported 
dysgeusia. The 3 participants with elevated TSH results did not experience related clinical 
symptoms and the free T4 results remained within reference range. 

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Based on review of preliminary (unaudited) data, all reported AEs have been of mild 
intensity. There have been no deaths, SAEs, or SUSARs reported. There were no clinically 
meaningful findings in vital signs, ECG, or potential Hy’s Law cases reported during this 
study. 
Further details on the clinical safety information with PF-07321332 are provided in the 
current IB.
2.2.4.2. Summary of PF-07321332 Pharmacokinetics in Human
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Further details on the clinical PK of PF-07321332 are provided in the current IB.
2.3. Benefit/Risk Assessment
PF-07321332/ritonavir are not expected to provide any clinical benefit to healthy participants 
in this study. This study is designed primarily to estimate the PK of PF-07321332 following 
multiple doses of PF-07321332/ritonavir in healthy Chinese participants.
 
 
 
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More detailed information about the known and expected benefits and risks and reasonably 
expected adverse events of PF-07321332 may be found in the IB, which is the SRSD for 
PF-07321332. The SRSD for ritonavir4 is the corresponding approved label.

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2.3.1. Risk Assessment
Potential Risk of Clinical 
Significance
Summary of Data/Rationale for Risk
Mitigation Strategy
Study Intervention(s): PF-07321332
Emesis
Sporadic emesis was observed at ≥100 mg/kg/day of PF-07321332 in the 
15-day NHP toxicology study (See IB). Based on preliminary data, no 
emesis was observed in the FIH Study C4671001 at single doses of 
PF-07321332 up to 1500 mg alone and up to 750 mg administered with 
ritonavir (100 mg at -12 h, 0 h, 12 h), and at repeated daily doses 
administered orally for 10 days of up to 500 mg PF-07321332 q12h with 
100 mg ritonavir q12h.
As this is an investigational agent, there is 
some risk that is mitigated by close 
observation of AEs, etc. If needed, 
palliative care or antiemetics may be 
provided.
Neuronal and pulmonary effects
Transient effect in rat neuronal and pulmonary endpoints were observed 
in rat toxicology study at the high dose level (1000 mg/kg as single dose; 
See IB). Based on preliminary data, no AEs suggestive of neuronal or 
pulmonary effects were observed in the FIH Study C4671001 at single 
doses of PF-07321332 up to 1500 mg alone and up to 750 mg 
administered with ritonavir (100 mg at -12 h, 0 h, 12 h), and at repeated 
daily doses administered orally for 10 days of up to 500 mg 
PF-07321332 q12h with 100 mg ritonavir q12h.
Vital signs, including respiratory rate, 
will be monitored for pulmonary effect. 
There will be close observation of AEs 
for any signs of neuronal effect.
Hemodynamic effects
Low level inflammation (increase in fibrinogen) in 15-day NHP 
toxicology study and changes in platelets, globulin and albumin/globulin 
ratio and coagulation system (increase in PT and aPTT) in 14-day rat 
toxicology study (See IB). No relevant laboratory changes in 
inflammatory markers have been observed in the FIH Study C4671001 at 
single doses of PF-07321332 up to 1500 mg alone and up to 750 mg 
administered with ritonavir (100 mg at -12 h, 0 h, 12 h), and at repeated 
daily doses administered orally for 10 days of up to 500 mg 
PF-07321332 q12h with 100 mg ritonavir q12h.
Fibrinogen, platelets, PT/INR and aPTT, 
albumin and total proteins will be 
monitored. 
Thyroid function studies
In 14-day rat toxicology study at high dose of PF-07321332 
(1000 mg/kg/day) thyroid gland changes observed were of low severity 
and without evidence of tissue damage. In the FIH Study C4671001,
3 participants had TEAEs of elevated TSH levels across treatment groups 
TSH and free T4 will be evaluated to 
monitor thyroid function
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Potential Risk of Clinical 
Significance
Summary of Data/Rationale for Risk
Mitigation Strategy
(PF-07321332 or placebo with ritonavir 100 mg q12h) in the MAD part 
of the study. There was no clinical correlation with these TSH changes 
and free T4 remained within reference range at all times.
Study Intervention(s): Ritonavir
Gastrointestinal disturbances 
(including diarrhea, nausea, vomiting 
and abdominal pain).
Frequently reported adverse reaction in HIV patients at 600 mg BID.
Lower dose of 100 mg twice daily is used 
in this study. There will be close 
observation of AEs. If needed, anti-
emetics may be provided. 
Neurological disturbances (eg, 
paresthesia, including oral 
paresthesia, dysgeusia and dizziness).
Frequently reported adverse reaction in HIV patients at 600 mg BID.
Lower dose used in this study. There will 
be close observation of AEs.
Rash (most commonly reported as 
erythematous and maculopapular, 
followed by pruritus).
Frequently reported adverse reaction in HIV patients at 600 mg BID.
Lower dose used in this study. There will 
be close observation of AEs and 
monitoring through targeted physical 
examinations. If needed, palliative care 
may be provided. 
Fatigue/Asthenia.
Frequently reported adverse reaction in HIV patients at 600 mg BID.
Lower dose used in this study. There will 
be close observation of AEs and 
monitoring through targeted physical 
examinations.
Limited case reports of renal toxicity
Although ritonavir therapy is not generally considered nephrotoxic, a 
limited number of cases of acute kidney injury secondary to ritonavir 
have been reported post-marketing in HIV patients.
Lower dose used in this study. There will 
be close observation of AEs and renal 
function.

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2.3.2. Benefit Assessment
PF-07321332/ritonavir will not provide any clinical benefit to healthy participants in this 
study. Any anticipated benefit to participants would be in terms of contribution to the process 
of developing a new therapy in an area of unmet medical need.
2.3.3. Overall Benefit/Risk Conclusion
PF-07321332/ritonavir are not expected to provide any clinical benefit to healthy participants 
in this study. Taking into account the measures taken to minimize risk to participants of this 
study, the potential risks identified in association with administration of 
PF-07321332/ritonavir are justified by the anticipated benefit, in terms of contribution to the 
process of developing a new therapy in an area of unmet medical need.
3. OBJECTIVES AND ENDPOINTS
Objectives
Endpoints
Primary: 
Primary: 
•
To characterize the plasma PK of PF-07321332 
when PF-07321332/ritonavir is administered in 
healthy Chinese participants
•
PF-07321332 plasma PK parameters:
•
Day 1: Cmax, Tmax, AUC12
•
Day 5, 8,10 (pre-dose and 12 hours after last 
dose): Ctrough
•
Day 10: Cmax, Tmax, AUCtau; and if data 
permit, AUClast, Cav, Rac, Rac,Cmax, PTR, 
CL/F, Vz/F and t½
Secondary: 
Secondary: 
•
To determine the safety and tolerability of 
PF-07321332/ritonavir in healthy Chinese 
participants after dose administration
•
To characterize the plasma PK of ritonavir 
following PF-07321332/ritonavir
administration in healthy Chinese participants
•
AEs, clinical safety laboratory tests, vital signs, 
12-lead ECGs
•
Ritonavir plasma PK parameters:
•
Day 1: Cmax, Tmax, AUC12
•
Day 5, 8,10 (pre-dose and 12 hours after last 
dose): Ctrough
•
Day 10: Cmax, Tmax, AUCtau; and if data 
permit, AUClast, Cav, CL/F, Vz/F and t½
 
 
 
4. STUDY DESIGN
4.1. Overall Design
This is a Phase 1, open-label study to estimate the PK, safety and tolerability of PF-07321332 
when PF-07321332/ritonavir is administered in healthy Chinese participants. The study will 
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consist of 1 treatment: 10-day oral doses of 300 mg PF-07321332/100 mg ritonavir. A total 
of approximately 14 healthy male and/or female participants will be enrolled into the study to 
ensure at least 12 participants will complete the study. Participants who discontinue from the 
study for non-safety reasons may be replaced at the sponsor’s discretion in collaboration with 
the Investigator.
The total duration of participation in this study is approximately 73 days, including a 
screening period of up to 28 days to confirm eligibility, treatment duration about 12 days 
(10 days of dose duration and another 2 days of full PK profile duration) and a follow-up 
period of approximately 28-35 days post the last dose of study intervention. 
Participants will be admitted to the CRU on Day -1 and may be discharged at the discretion 
of the investigator following completion of assessments per protocol requirement on Day 12
(2 days after last dose on Day 10).
All of participants will receive PF-07321332 and ritonavir together. The dose regimen is 
PF-07321332/ritonavir 300/100 mg q12h for a total of 19 oral doses (Day 1 to Day 10). The 
first dose and the last dose will be recommended to be administrated on Day 1 and Day 10 
morning, respectively, for intensive PK sample collection feasibility. The evening dose will
not be given on Day 10. 
Following discharge on Day 12 after last PK and safety assessment, follow-up contact may 
occur via telephone and must occur 28 to 35 days after the last dose of investigational 
product, or via on-site visit if it is necessary per investigator’s evaluation. Participants who 
prematurely discontinue for non-safety related reasons may be replaced, at the discretion of 
the principal investigator and sponsor study team.
4.2. Scientific Rationale for Study Design
Considering the dose 
duration in Phase 2/3 studies may be up to 5 or 10 days, a 10-day safety profile in Chinese 
healthy participants would be beneficial to describe the safety characteristic in the Chinese 
population and justify the ethnic difference. Therefore a 10-day dosing duration is planned, 
based on maximum duration of dosing in global C4671006 study.
The purpose of the study is to investigate the PK, safety and tolerability of PF-07321332 
following repeated oral doses in combination with a PK boosting agent ritonavir in Chinese 
healthy adults. One (or more) suitable Western study(ies) will be selected for comparison 
between Western and Chinese populations. This may involve comparison of Day 1 data 
and/or steady-state data (generally reached by Day 2) with the data obtained from the 
Chinese Phase 1 study.
 
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4.2.1. Choice of Contraception/Barrier Requirements 
Human reproductive safety data are limited for PF-07321332, but there is no suspicion of 
human teratogenicity based on the intended pharmacology of the compound. Therefore, the 
use of a highly effective method of contraception is required (see Appendix 4).
4.3. Justification for Dose
This study is designed to estimate the PK, safety of multiple dose administration of 
PF-07321332 and ritonavir when both of them administrated together. A dose of 300 mg 
PF-07321332, pharmacokinetically enhanced with 100 mg ritonavir, to be administered q12h 
for 10 days will be used in this study. This dose is the intended therapeutic dose to be 
evaluated in Phase 2/3 studies and is appropriate considering concomitant administration of 
PF-07321332 with ritonavir provides near maximal CYP3A4 inhibition. 
When co-administered with ritonavir, doses of PF-07321332 up to 750 mg single dose and 
500 mg q12h for 10 days were generally safe and well tolerated based on preliminary data 
form the Phase 1 Study C4671001. There have been no deaths or SAEs or SUSARs reported. 
Based on review of preliminary (unaudited) data, all reported adverse events have been of 
mild intensity. There were no clinically meaningful findings in vital signs, ECG, or potential 
Hy’s Law cases reported during the study. 
Furthermore, doses up to 500 mg PF-07321332/100 mg ritonavir administered orally q12h 
for 10 days have been studied in healthy participants in Study C4671001. 
 
 
 
 
 
 
 
 
 
 
 
 
4.4. End of Study Definition
The end of the study is defined as the date of the last scheduled procedure shown in the SoA
for the last participant in the trial.
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A participant is considered to have completed the study if he/she has completed all periods of 
the study, including the last scheduled procedure shown in the SoA.
5. STUDY POPULATION
This study can fulfill its objectives only if appropriate participants are enrolled. The 
following eligibility criteria are designed to select participants for whom participation in the 
study is considered appropriate. All relevant medical and nonmedical conditions should be 
taken into consideration when deciding whether a particular participant is suitable for this 
protocol.
Prospective approval of protocol deviations to recruitment and enrollment criteria, also 
known as protocol waivers or exemptions, is not permitted.
5.1. Inclusion Criteria
Participants are eligible to be included in the study only if all of the following criteria apply:
Age and Sex:
1. Chinese participants must be 18 to 60 years of age, inclusive, at the time of signing 
the ICD. Among enroll participants, both female and male participants need to be 
included. 

Refer to Appendix 4 for reproductive criteria for male (Section 10.4.1) and female
(Section 10.4.2) participants.
Type of Participant and Disease Characteristics:
2. Male and female participants who are overtly healthy as determined by medical 
evaluation including medical history, physical examination, laboratory tests, vital 
signs and standard 12-lead ECGs.
3. Participants who are willing and able to comply with all scheduled visits, treatment 
plan, laboratory tests, lifestyle considerations, and other study procedures.
Weight:
4. BMI of 17.5 to 28 kg/m2, inclusive; and a total body weight >50 kg (110 lb).
Informed Consent:
5. Capable of giving signed informed consent as described in Appendix 1, which 
includes compliance with the requirements and restrictions listed in the ICD and in 
this protocol.

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5.2. Exclusion Criteria
Participants are excluded from the study if any of the following criteria apply:
Medical Conditions:
1. Positive test result at the investigator’s discretion for SARS-CoV-2 infection at the 
time of Screening or Day -1.
2. Evidence or history of clinically significant hematological, renal, endocrine, 
pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or 
allergic disease (including drug allergies, but excluding untreated, asymptomatic, 
seasonal allergies at the time of dosing).
3. Clinically relevant abnormalities requiring treatment (eg, acute myocardial infarction, 
unstable ischemic conditions, evidence of ventricular dysfunction, serious tachy or 
brady arrhythmias) or indicating serious underlying heart disease (eg, prolonged PR 
interval, cardiomyopathy, heart failure greater than NYHA 1, underlying structural 
heart disease, Wolff Parkinson-White syndrome). 
4. Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy).
5. History of HIV infection, hepatitis B, or hepatitis C; positive testing for HIV, HbsAg, 
HbcAb, or HCVAb. Hepatitis B vaccination is allowed.
6. History of sensitivity reactions to ritonavir, or any of the formulation components of 
PF-07321332 and ritonavir.
7. Pregnant or breastfeeding women.
8. Other medical or psychiatric condition including recent (within the past year) or 
active suicidal ideation/behavior or laboratory abnormality or other conditions or 
situations related to COVID-19 pandemic (eg. Contact with positive case, residence, 
or travel to an area with high incidence) that may increase the risk of study 
participation or, in the investigator’s judgment, make the participant inappropriate for 
the study.
Prior/Concomitant Therapy:
9. Use of prescription or nonprescription drugs and dietary and herbal supplements 
within 7 days or 5 half-lives (whichever is longer) prior to the first dose of study 
intervention (Refer to Section 6.8 Concomitant Therapy for additional details).
10. Current use of any prohibited concomitant medication(s) or those unwilling/unable to 
use a permitted concomitant medication(s). Refer to Section 6.8 Concomitant 
Therapy.

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11. Participant who have received a COVID-19 vaccine recently which may impact the 
study evaluation, by the investigator’s discretion based on symptoms or impact on 
safety lab testing.
Prior/Concurrent Clinical Study Experience:
12. Previous administration with an investigational drug within 30 days (or as determined 
by the local requirement) or 5 half-lives preceding the first dose of study intervention
used in this study (whichever is longer). 
Diagnostic Assessments:
13. A positive urine drug test.
14. Screening supine BP ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic), following at 
least 5 minutes of supine rest. If BP is ≥140 mm Hg (systolic) or ≥90 mm Hg 
(diastolic), the BP should be repeated 2 more times and the average of the 3 BP 
values should be used to determine the participant’s eligibility.
15. Baseline standard 12-lead ECG that demonstrates clinically relevant abnormalities that
may affect participant safety or interpretation of study results (eg, baseline QTcF
interval >450 msec, complete LBBB, signs of an acute or indeterminate-age 
myocardial infarction, ST-T interval changes suggestive of myocardial ischemia, 
second- or third-degree AV block, or serious bradyarrhythmias or tachyarrhythmias). 
If the baseline uncorrected QT interval is >450 msec, this interval should be 
rate-corrected using the Fridericia method and the resulting QTcF should be used for 
decision making and reporting. If QTcF exceeds 450 msec, or QRS exceeds 
120 msec, the ECG should be repeated 2 more times and the average of the 3 QTcF or 
QRS values should be used to determine the participant’s eligibility.
Computer-interpreted ECGs should be overread by a physician experienced in 
reading ECGs before excluding a participant. The average of triplicate measurement 
should be used for eligibility determination.
16. Participants with ANY of the following abnormalities in clinical laboratory tests at 
screening, as assessed by the study-specific laboratory and confirmed by a single 
repeat test, if deemed necessary: 

AST or ALT level >1.0 × ULN;

Total bilirubin level ≥1.5 × ULN; participants with a history of Gilbert’s 
syndrome may have direct bilirubin measured and would be eligible for this study 
provided the direct bilirubin level is ≤ULN;

eGFR <90 mL/min/1.73 m2 (with 10% variation) based on the CKD-EPI 
equation.5 The following CKD-EPI equation will be used to calculate eGFR 

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(Scr, std denotes serum creatinine measured with a standardized assay for serum 
creatinine):
If female and SCr is ≤0.7 mg/dL:
eGFR (mL/min/1.73 m2) = 144 × (SCr, std/0.7) – 0.329 × 0.993age (× 1.159, if Black)
If female and SCr is >0.7 mg/dL:
eGFR (mL/min/1.73 m2) = 144 × (SCr, std /0.7) – 1.209 × 0.993age (× 1.159, if Black)
If male and SCr is ≤0.9 mg/dL:
eGFR (mL/min/1.73 m2) = 141 × (SCr, std /0.9) – 0.411 × 0.993age (× 1.159, if Black)
If male and SCr is >0.9 mg/dL:
eGFR (mL/min/1.73 m2) = 141 × (SCr, std /0.9) – 1.209 × 0.993age (× 1.159, if Black)
Other Exclusions:
17. History of alcohol abuse or binge drinking and/or any other illicit drug use or 
dependence within 6 months of Screening. Binge drinking is defined as a pattern of 
5 (male) and 4 (female) or more alcoholic drinks in about 2 hours. As a general rule, 
alcohol intake should not exceed 14 units per week (1 unit = 8 ounces (240 mL) beer, 
1 ounce (30 mL) of 40% spirit or 3 ounces (90 mL) of wine).
18. Use of tobacco or nicotine containing products in excess of the equivalents of 
5 cigarettes per day or 2 chews of tobacco per day.
19. Blood donation (excluding plasma donations) of approximately 1 pint (500 mL) or 
more within 60 days prior to dosing.
20. History of sensitivity to heparin or heparin-induced thrombocytopenia.
21. Unwilling or unable to comply with the criteria in the Lifestyle Considerations
section of this protocol.
22. Investigator site staff or Pfizer employees directly involved in the conduct of the 
study, site staff otherwise supervised by the investigator, and their respective family 
members.

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5.3. Lifestyle Considerations
The following guidelines are provided:
5.3.1. Meals and Dietary Restrictions

Participants must abstain from all food and drink (except water) at least 4 hours prior 
to any safety laboratory evaluations (includes hematology, chemistry, urinalysis and 
coagulation test).

At least a 2-hour fast is required before and after drug administration for all dose.

Water is restricted 1 hour prior to study intervention administration for all doses
(except water used to swallow drugs). Water may be consumed without restriction 
beginning 1 hour after morning dosing of Day 1 and Day 10, and may be consumed 
without restriction after morning dosing on non-PK days and all evening doses.
Noncaffeinated drinks (except grapefruit or grapefruit-related citrus fruit juices—see 
below) may be permitted with meals and the evening snack.

An evening snack may be permitted.

Participants will refrain from consuming red wine, grapefruit, or grapefruit-related 
citrus fruits (eg, Seville oranges, pomelos, fruit juices) from 7 days prior to the first 
dose of study intervention until collection of the final PK blood sample. 

While participants are confined, all meals need to provided by clinical research unit 
as standard meal. 
5.3.2. Caffeine, Alcohol, and Tobacco

Participants will abstain from caffeine-containing products for 24 hours prior to the 
start of dosing until collection of the final PK sample. 

Participants will abstain from alcohol for 24 hours to admission to the CRU and 
continue abstaining from alcohol until collection of the final PK sample. Participants 
may undergo an alcohol breath test or blood alcohol test at the discretion of the 
investigator.

Participants will abstain from the use of tobacco- or nicotine-containing products for 
24 hours prior to dosing and during confinement in the CRU.
5.3.3. Activity

Participants will abstain from strenuous exercise (eg, heavy lifting, weight training, 
calisthenics, aerobics) for at least 48 hours prior to each blood collection for clinical 
laboratory tests. Walking at a normal pace will be permitted;

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
In order to standardize the conditions on PK sampling days, participants will be 
required to maintain daily activities (such as sitting or walking at a normal pace, 
except when required for BP, PR, and ECG measurements), and refrain from drinking 
beverages other than water during the first 2 hours after dosing.
5.3.4. Contraception
The investigator or his or her designee, in consultation with the participant, will confirm that 
the participant has selected an appropriate method of contraception for the individual 
participant from the permitted list of contraception methods (see Appendix 4 Section 10.4.4)
and will confirm that the participant has been instructed in its consistent and correct use. At 
time points indicated in the schedule of activities (SoA), the investigator or designee will 
inform the participant of the need to use highly effective contraception consistently and 
correctly and document the conversation and the participant’s affirmation in the participant’s 
chart (participants need to affirm their consistent and correct use of at least 1 of the selected 
methods of contraception) considering that their risk for pregnancy may have changed since 
the last visit. In addition, the investigator or designee will instruct the participant to call 
immediately if the selected contraception method is discontinued or if pregnancy is known or 
suspected in the participant or partner.
5.4. Screen Failures
Screen failures are defined as participants who consent to participate in the clinical study but 
are not subsequently enrolled in the study. Screen failure data are collected and remain as 
source and are not reported on the CRF.
Individuals who do not meet the criteria for participation in this study (screen failure) may be 
rescreened, at the discretion of the investigator. 
6. STUDY INTERVENTION(S) AND CONCOMITANT THERAPY
Study intervention is defined as any investigational intervention(s), marketed product(s), 
placebo, medical device(s), or study procedure(s) intended to be administered to a study 
participant according to the study protocol.
For the purposes of this protocol, study intervention refers to PF-07321332 and ritonavir.
6.1. Study Intervention(s) Administered
PF-07321332 will be provided by Pfizer as tablet at the CRU, and will be supplied to the 
CRU in bulk bottle and will dispensed in individual dosing containers for unit dosing to 
participants.
Ritonavir will be provided by Pfizer as 100 mg tablets. 
6.1.1. Administration
Investigational products will be administered orally and according to the conditions 
described in the SoA section and Protocol Section 5.3.1 Meals and Dietary Restrictions.

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On Day 1 following a fast of at least 2 hours, participants will receive 300 mg PF-07321332, 
administered orally with 100 mg ritonavir (as 1 × 100 mg tablet) administered orally starting
in the morning. PF-07321332 and ritonavir will be dosed simultaneously (within no more 
than 5 minutes of each other). Participants will receive 300 mg PF-07321332, with 100 mg 
ritonavir (as 1 × 100 mg tablet) administered orally q12h (±30 min) for a total of 19 doses, 
with the last dose administered on the morning of Day 10 (no evening dose on Day 10). The 
dose interval between first dose and second dose on Day 1 needs to no less than 12 hours, to 
allow 12 hours for sample collection prior to start of Day 1 evening dosing. Participants will 
swallow both tablets whole and will not chew prior to swallowing. 
Investigator site personnel will administer study intervention with ambient temperature water 
to a total volume of approximately 240 mL. Study intervention will be administered 
according to the protocol.
6.2. Preparation, Handling, Storage, and Accountability
1. The investigator or designee must confirm appropriate temperature conditions have 
been maintained during transit for all study interventions received and any 
discrepancies are reported and resolved before use of the study intervention. 
2. Only participants enrolled in the study may receive study intervention and only 
authorized site staff may supply or administer study intervention. All study 
interventions must be stored in a secure, environmentally controlled, and monitored 
(manual or automated recording) area in accordance with the labeled storage 
conditions with access limited to the investigator and authorized site staff. At a 
minimum, daily minimum and maximum temperatures for all site storage locations 
must be documented and available upon request. Data for nonworking days must 
indicate the minimum and maximum temperatures since previously documented for 
all site storage locations upon return to business.
3. Any excursions from the study intervention label storage conditions should be 
reported to Pfizer upon discovery along with any actions taken. The site should 
actively pursue options for returning the study intervention to the storage conditions 
described in the labeling, as soon as possible. Once an excursion is identified, the 
study intervention must be quarantined and not used until Pfizer provides permission 
to use the study intervention. Specific details regarding the definition of an excursion 
and information the site should report for each excursion will be provided to the site 
in the IP manual or other specified location.
4. Any storage conditions stated in the SRSD will be superseded by the storage 
conditions stated on the label.
5. Study interventions should be stored in their original containers.
6. The investigator, institution, or the head of the medical institution (where applicable) 
is responsible for study intervention accountability, reconciliation, and record 

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maintenance (ie, receipt, reconciliation, and final disposition records), such as the 
IPAL or sponsor-approved equivalent. All study interventions will be accounted for 
using a study intervention accountability form/record.
7. Further guidance and information for the final disposition of unused study 
interventions are provided in the IP manual or other specified location. All 
destruction must be adequately documented. If destruction is authorized to take place 
at the investigator site, the investigator must ensure that the materials are destroyed in 
compliance with applicable environmental regulations, institutional policy, and any 
special instructions provided by Pfizer.
Upon identification of a product complaint, notify the sponsor within 1 business day of 
discovery as described in the IP manual.
6.2.1. Preparation and Dispensing
Within this protocol, preparation refers to the investigator site activities performed to make 
the study intervention ready for administration or dispensing to the participant by qualified 
staff. Dispensing is defined as the provision of study intervention, concomitant treatments, 
and accompanying information by qualified staff member(s) to a healthcare provider, 
participant in accordance with this protocol. Local health authority regulations or investigator 
site guidelines may use alternative terms for these activities.
See the package insert, or equivalent for instructions on how to prepare the study intervention
(ritonavir) for administration. Study intervention should be prepared and dispensed by an 
appropriately qualified and experienced member of the study staff (eg, physician, nurse, 
physician’s assistant, nurse practitioner, pharmacy assistant/technician, or pharmacist) as
allowed by local, state, and institutional guidance. A second staff member will verify the 
dispensing.
Tablets (PF-07321332) will be prepared at the CRU as single dose and provided to 
participants by 2 operators, 1 of whom is an appropriately qualified and experienced member 
of the study staff (eg, physician, nurse, physician’s assistant, nurse practitioner, pharmacy 
assistant/technician, or pharmacist). The tablets will be provided in unit dose containers and 
labeled in accordance with Pfizer regulations and the clinical site’s labeling requirements. 
6.3. Measures to Minimize Bias: Randomization and Blinding
6.3.1. Allocation to Study Intervention
The investigator’s knowledge of the treatment should not influence the decision to enroll a 
particular participant or affect the order in which participants are enrolled.
The investigator will assign participant numbers to the participants as they are screened for 
the study. Pfizer will provide a randomization schedule to the investigator and, in accordance 
with the randomization numbers, the participant will receive the study treatment regimen 
assigned to the corresponding randomization number.

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6.4. Study Intervention Compliance
When the individual dose for a participant is prepared from a bulk supply, the preparation of 
the dose will be confirmed by a second qualified member of the study site staff.
When participants are dosed at the site, they will receive study intervention directly from the 
investigator or designee, under medical supervision. The date and time of each dose 
administered in the clinic will be recorded in the source documents and recorded in the CRF. 
The dose of study intervention and study participant identification will be confirmed at the 
time of dosing by a member of the study site staff other than the person administering the 
study intervention. Study site personnel will examine each participant’s mouth to ensure that 
the study intervention was ingested.
6.5. Dose Modification
No dose modification is anticipated.
6.6. Continued Access to Study Intervention After the End of the Study
No intervention will be provided to study participants at the end of their study participation.
6.7. Treatment of Overdose
For this study, any dose of PF-07321332 greater than 600 mg or ritonavir greater than 
200 mg within a 24-hour time period ±2 hours will be considered an overdose.
There is no specific treatment for an overdose.
In the event of an overdose, the investigator should:
1. Contact the medical monitor within 24 hours.
2. Closely monitor the participant for any AEs/SAEs and laboratory abnormalities for at 
least 5 half-lives or 28 calendar days after the overdose of PF-07321332 or ritonavir
(whichever is longer).
3. Document the quantity of the excess dose as well as the duration of the overdose in 
the CRF.
4. Overdose is reportable to Pfizer Safety only when associated with an SAE.
5. Obtain a blood sample for PK analysis within 1 days from the date of the last dose of 
study intervention if requested by the medical monitor (determined on a case-by-case 
basis).
Decisions regarding dose interruptions or modifications will be made by the investigator in 
consultation with the medical monitor based on the clinical evaluation of the participant.

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6.8. Concomitant Therapy
Use of prescription or nonprescription drugs and dietary and herbal supplements are 
prohibited within 7 days or 5 half-lives (whichever is longer) prior to the first dose of study 
intervention. Limited use of nonprescription medications that are not believed to affect 
participant safety or the overall results of the study may be permitted on a case-by-case basis 
following approval by the sponsor. Acetaminophen/paracetamol may be used at doses of 
≤1 g/day.
Hormonal contraceptives that meet the requirements of this study are allowed to be used in 
participants who are WOCBP (see Appendix 4).
Females using hormonal contraceptives or taking hormone replacement therapy may be 
eligible to participate in this study if they are willing to discontinue therapy at least 28 days 
prior to the first dose of study treatment and remain off hormonal therapy for the duration of 
the study. Depo-Provera® must be discontinued at least 6 months prior to the first dose of 
study treatment.
All concomitant treatments taken during the study must be recorded with indication, daily 
dose, and start and stop dates of administration. All participants will be questioned about 
concomitant treatment at admission.
Treatments taken within 28 days before the first dose of study intervention will be 
documented as a prior treatment. Treatments taken after the first dose of study intervention 
will be documented as concomitant treatments.
6.8.1. Rescue Medicine 
There is no rescue therapy to reverse the AEs observed with PF-07321332 and ritonavir; 
standard medical supportive care must be provided to manage the AEs, at the discretion of
investigators. 
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 
for permanent discontinuation of study intervention include the following:

AE requiring discontinuation in investigator’s view;

Pregnancy;

Positive COVID-19 test.

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If study intervention is permanently discontinued, the participant will not remain in the study 
for further evaluation. See the SoA for data to be collected at the time of discontinuation of 
study intervention.
7.1.1. ECG Changes
A participant who meets either bulleted criterion based on the average of triplicate ECG 
readings will be withdrawn from the study intervention. 

QTcF >500 msec.

QTcF Change from baseline >60 msec and QTcF >450 msec.
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.
7.1.2. Potential Cases of Acute Kidney Injury
Abnormal values in SCr concurrent with presence or absence of increase in BUN that meet 
the criteria below, in the absence of other causes of kidney injury, are considered potential 
cases of acute kidney injury and should be considered important medical events. 
An increase of ≥0.3 mg/dL (or ≥26.5 µmol/L) in SCr level relative to the participant’s own 
baseline measurement should trigger a halt/stopping of dosing, followed by another 
assessment of SCr as soon as practically feasible, preferably within 48 hours from awareness.
If the second assessment (after the first observations of ≥0.3 mg/dL [or ≥26.5 µmol/L] in SCr
relative to the participant’s own baseline measurement) confirms the observation of 
≥0.3 mg/dL (or ≥26.5 µmol/L), the participant should be discontinued from the study and 
adequate, immediate, supportive measures taken to correct apparent acute kidney injury.
Participants should return to the investigator site and be evaluated as soon as possible, 
preferably within 48 hours from awareness of the abnormal SCr result. This evaluation 
should include laboratory tests, detailed history, and physical assessment. In addition to 
repeating SCr, laboratory tests should include serum BUN, serum creatine kinase, and serum 
electrolytes (including at a minimum potassium, sodium, phosphate/phosphorus, and 
calcium), in addition to urinary dipstick, urine microscopic examination, and urinary indices. 
All cases confirmed on repeat testing as meeting the laboratory criteria for acute kidney 
injury, with no other cause(s) of laboratory abnormalities identified, should be considered 
potential cases of drug-induced kidney injury irrespective of availability of all the results of 
the investigations performed to determine etiology of the abnormal SCr. If ≥2 healthy 
participants are noted to have 2 consecutive SCr results change from baseline of ≥0.3 mg/dL 
(or ≥26.5 µmol/L), an assessment of whether the finding may be considered an adverse drug 
reaction should be undertaken.

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7.1.3. Stopping Rules
Dosing will be halted at any time if 1 of the following circumstances occurs and it is 
determined by the investigator that the occurrence is at least possibly related to the 
administration of study drug:

A SAE (eg, a serious AE considered at least possibly related to study drug 
administration) in 1 participant.

Severe NSAE (eg, severe NSAEs considered at least possibly related to study drug 
administration) in 2 participants.
When stopping rules are met, a data review will be conducted by the sponsor and 
investigator. If integrated analysis of available data leads to the conclusion that further dosing 
is justified, an amendment to the protocol may be required if additional safety monitoring is 
warranted.
7.2. Participant Discontinuation/Withdrawal From the Study
A participant may withdraw from the study at any time at his/her own request. Reasons for 
discontinuation from the study include the following:

Refused further study procedures;

Lost to follow-up;

Death;

Study terminated by sponsor;

Investigator’s decision

Pregnancy

Other reasons that may make the participant not evaluable for the primary endpoints
at the evaluation by investigators and sponsor. 
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, he/she may request destruction of any remaining 
samples taken and not tested, and the investigator must document any such requests in the 
site study records and notify the sponsor accordingly.

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If the participant withdraws from the study and also withdraws consent (see Section 7.2.1) 
for disclosure of future information, no further evaluations should be performed and no 
additional data should be collected. The sponsor may retain and continue to use any data 
collected before such withdrawal of consent.
7.2.1. 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 him or her 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 he or she 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, he/she will be considered to have 
withdrawn from the study. 
8. STUDY ASSESSMENTS AND PROCEDURES
The investigator (or an appropriate delegate at the investigator site) must obtain a signed and 
dated ICD before performing any study-specific procedures. 

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Study procedures and their timing are summarized in the SoA. Protocol waivers or 
exemptions are not allowed.
Safety issues should be discussed with the sponsor immediately upon occurrence or 
awareness to determine whether the participant should continue or discontinue study 
intervention.
Adherence to the study design requirements, including those specified in the SoA, is essential 
and required for study conduct.
All screening evaluations must be completed and reviewed to confirm that potential 
participants meet all eligibility criteria. The investigator will maintain a screening log to 
record details of all participants screened and to confirm eligibility or record reasons for 
screening failure, as applicable.
Participants will be screened within 28 days prior to administration of the study intervention
to confirm that they meet the study population criteria for the study. If the time between 
screening and dosing exceeds 28 days as a result of unexpected delays (eg, delayed drug 
shipment), then participants do not require rescreening if the laboratory results obtained prior 
to first dose administration meet eligibility criteria.
Every effort should be made to ensure that protocol-required tests and procedures are 
completed as described. However, it is anticipated that from time to time there may be 
circumstances outside the control of the investigator that may make it unfeasible to perform 
the test. In these cases, the investigator must take all steps necessary to ensure the safety and 
well-being of the participant. When a protocol-required test cannot be performed, the 
investigator will document the reason for the missed test and any corrective and preventive 
actions that he or she has taken to ensure that required processes are adhered to as soon as 
possible. The study team must be informed of these incidents in a timely manner.
If an IV catheter is utilized for blood sample collections, ECGs and vital sign assessments 
(PR and BP) should be collected prior to the insertion of the catheter.
For samples being collected and shipped, detailed collection, processing, storage, and 
shipment instructions and contact information will be provided to the investigator site prior 
to initiation of the study.
The total blood sampling volume for individual participants in this study is approximately 
190 mL. The actual collection times of blood sampling may change. Additional blood 
samples may be taken for safety assessments at times specified by Pfizer, provided the total 
volume taken during the study does not exceed 550 mL during any period of 56 consecutive 
days.
To prepare for study participation, participants will be instructed on the information in the 
Lifestyle Considerations and Concomitant Therapy sections of the protocol.

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8.1. Efficacy Assessments
Not applicable. 
8.2. Safety Assessments
Planned time points for all safety assessments are provided in the SoA. Unscheduled clinical 
laboratory measurements may be obtained at any time during the study to assess any 
perceived safety issues.
8.2.1. Physical Examinations
A complete physical examination will include, at a minimum, head, ears, eyes, nose, mouth, 
skin, heart and lung examinations, lymph nodes, and gastrointestinal, musculoskeletal, and 
neurological systems. 
A brief physical examination will include, at a minimum, assessments of general appearance, 
the respiratory and cardiovascular systems, and participant-reported symptoms.
Physical examinations may be conducted by a physician.
Height and weight will also be measured and recorded as per the SoA. For measuring weight, 
a scale with appropriate range and resolution is used and must be placed on a stable, flat 
surface. Participants must remove shoes, bulky layers of clothing, and jackets so that only 
light clothing remains. They must also remove the contents of their pockets and remain still 
during measurement of weight. 
Physical examination findings collected during the study will be considered source data 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 
definition of an AE or SAE (Appendix 3) must be reported according to the processes in 
Sections 8.3.1 to 8.3.3.
8.2.2. Vital Signs
Vital signs test will include blood pressure, pulse rate, respiratory rate and temperature.
Supine BP will be measured with the participant’s arm supported at the level of the heart, and 
recorded to the nearest mm Hg after at least 5 minutes of supine rest. The same arm 
(preferably the dominant arm) should be used throughout the study as possible. Participants 
should be instructed not to speak during measurements.
The same properly sized and calibrated BP cuff will be used to measure BP each time. The 
use of an automated device for measuring BP and PR is acceptable; however, when done 
manually, PR will be measured in the brachial/radial artery for at least 30 seconds. When the 
timing of these measurements coincides with a blood collection, BP and PR should be 
obtained prior to the nominal time of the blood collection.

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Additional collection times, or changes to collection times, of BP and PR will be permitted, 
as necessary, to ensure appropriate collection of safety data.
8.2.2.1. Respiratory Rate
Respiratory rate will be measured after at least 5 minutes of rest in a supine position by 
observing and counting the respirations of the participant for 30 seconds and multiplying by 
2. When BP is to be taken at the same time, respiration measurement will be done during at 
least 5 minutes of rest and before BP measurement.
8.2.2.2. Temperature
Temperature will be measured according investigator’s discretion (eg, tympanic, are 
acceptable provided the same method is used and documented throughout the study). No 
eating, drinking, or smoking is allowed for 15 minutes prior to the measurement.
8.2.3. Electrocardiograms
Standard 12-lead ECGs utilizing limb leads (with a 10 second rhythm strip) should be 
collected at times specified in the SoA section of this protocol using an ECG machine that 
automatically calculates the heart rate and measures PR, QT, and QTc intervals and QRS 
complex. Alternative lead placement methodology using torso leads (eg, Mason-Likar) 
should not be used given the potential risk of discrepancies with ECGs acquired using 
standard limb lead placement. All scheduled ECGs should be performed after the participant
has rested quietly for at least 5 minutes in a supine position. 
To ensure safety of the participants, a qualified individual at the investigator site will make 
comparisons to baseline measurements. Additional ECG monitoring will occur if a) the mean 
value from the triplicate measurements for any postdose QTcF interval is increased by 
≥60 msec from the baseline and is >450 msec; or b) an absolute QT value is ≥500 msec for 
any scheduled ECG. If either of these conditions occurs, then a single ECG measurement 
must be repeated at least hourly until QTc values from 2 successive ECGs fall below the 
threshold value that triggered the repeat measurement.
If a) a postdose QTcF interval remains ≥60 msec from the baseline and is >450 msec; or b) 
an absolute QT value is ≥500 msec for any scheduled ECG for greater than 4 hours (or 
sooner, at the discretion of the investigator); or c) QTcF intervals get progressively longer, 
the participant should undergo continuous ECG monitoring. A cardiologist should be 
consulted if QTcF intervals do not return to less than the criteria listed above after 8 hours of 
monitoring (or sooner, at the discretion of the investigator).
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.

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ECG values of potential clinical concern are listed in Appendix 6.
8.2.4. Clinical Safety Laboratory Assessments
See Appendix 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, 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.
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. 
Clinically significant abnormal laboratory findings are those which 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 significantly abnormal during 
participation in the study or within 48 hours 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 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 5 for suggested actions and follow-up assessments in the event of potential 
drug-induced liver injury.
8.2.5. COVID-19 Specific Assessments
Participants will be tested for SARS-COVID-19 infection by PCR prior to being admitted to 
the clinic for confinement and a subsequent COVID-19 test will be performed if they develop 
COVID-19 like symptoms. Additional testing (eg. CT, COVID-19 antibody, etc) at screening 
or Day-1 may be required by local regulations or by the Principal Investigator. COVID-19 
temperature will be checked at least daily during the hospital stay in the clinical research 
unit.
8.2.6. Pregnancy Testing 
Pregnancy tests may be urine or serum tests, but must have a sensitivity of at least 
25 mIU/mL. Pregnancy tests will be performed in WOCBP at the times listed in the SoA. 
Following a negative pregnancy test result at screening, appropriate contraception must be 
commenced and a second negative pregnancy test result will be required at the baseline visit 
prior the participant’s receiving the study intervention. Pregnancy tests will also be done 
whenever 1 menstrual cycle is missed during the active treatment period (or when potential 
pregnancy is otherwise suspected) and at the end of the study. Pregnancy tests may also be 
repeated if requested by IRBs/ ECs or if required by local regulations. If a urine test cannot 
be confirmed as negative (eg, an ambiguous result), a serum pregnancy test is required. In 
such cases, the participant must be excluded if the serum pregnancy result is positive.

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8.2.7. Thyroid Ultrasound
Thyroid ultrasound should be conducted at least once before dosing. Investigator may choose 
to either collect at screening or Day -1 or both. Refer to CRU requirement for detailed 
operation method. 
Other thyroid ultrasounds are permitted to be conducted at any time of the investigator’s 
discretion.
8.3. Adverse Events, Serious Adverse Events, and Other Safety Reporting
The definitions of an AE and an SAE can be found in Appendix 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 8.3.1, each participant will be 
questioned about the occurrence of AEs in a nonleading manner.
In addition, the investigator may be requested by Pfizer Safety to obtain specific follow-up 
information in an expedited fashion.
8.3.1. Time Period and Frequency for Collecting AE and SAE Information
The time period for actively eliciting and collecting AEs and SAEs (“active collection 
period”) for each participant begins from the time the participant provides informed consent, 
which is obtained before the participant’s participation in the study (ie, before undergoing 
any study-related procedure and/or receiving study intervention), through and including a 
minimum of 28 calendar days, except as indicated below, after the last administration of the 
study intervention.
Follow-up by the investigator continues throughout and after the active collection period and 
until the AE or SAE or its sequelae resolve or stabilize at a level acceptable to the 
investigator.
For participants who are screen failures, the active collection period ends when screen failure 
status is determined.
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.

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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 completed the study, and he/she 
considers 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.
8.3.1.1. Reporting SAEs to Pfizer Safety
All SAEs occurring in a participant during the active collection period as described in 
Section 8.3.1 are reported to Pfizer Safety on the CT SAE Report Form immediately upon 
awareness and under no circumstance should this exceed 24 hours, as indicated in 
Appendix 3. The investigator will submit any updated SAE data to the sponsor within 
24 hours of it being available.
8.3.1.2. 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 8.3.1, will be recorded 
on the AE section of the CRF.
The investigator is to record on the CRF all directly observed and all spontaneously reported 
AEs and SAEs reported by the participant.
Reporting of AEs and SAEs for participants who fail screening are subject to the CRF 
requirements as described in Section 5.4.
8.3.2. Method of Detecting AEs and SAEs
The method of recording, evaluating, and assessing causality of AEs and SAEs and the 
procedures for completing and transmitting SAE reports are provided in Appendix 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.
8.3.3. 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 

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possible causality. Any information relevant to the event, such as concomitant medications 
and illnesses, must be provided. In the case of a participant death, a summary of available 
autopsy findings must be submitted as soon as possible to Pfizer Safety. 
Further information on follow-up procedures is given in Appendix 3.
8.3.4. Regulatory Reporting Requirements for SAEs
Prompt notification by the investigator to the sponsor of an SAE is essential so that legal 
obligations and ethical responsibilities 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.
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.
8.3.5. 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 exposure during pregnancy, exposure during 
breastfeeding, and occupational exposure.
Any such exposure to the study intervention under study are reportable to Pfizer Safety 
within 24 hours of investigator awareness.
8.3.5.1. Exposure During Pregnancy
An EDP occurs if: 

A female participant is found to be pregnant while receiving or after discontinuing 
study intervention.

A male participant who is receiving or has discontinued study intervention exposes a 
female partner prior to or around the time of conception.

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
A female is found to be pregnant while being exposed or having been exposed to 
study intervention due to 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 exposes 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 a participant’s partner, the investigator must report 
this information to Pfizer Safety on 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 28 days after 
the last dose.

If EDP occurs in the setting of environmental exposure, the investigator must report 
information to Pfizer Safety using the CT SAE Report Form and 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 CT SAE Report Form 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 EDP Supplemental Form. 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 
preprocedure 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;

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
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.
8.3.5.2. Exposure During Breastfeeding
An exposure during breastfeeding occurs if: 

A female participant is found to be breastfeeding while receiving or after 
discontinuing study intervention.

A female is found to be breastfeeding while being exposed or having been exposed to 
study intervention (ie, environmental exposure). An example of environmental 
exposure during breastfeeding 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 exposure during breastfeeding 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 exposure during 
breastfeeding 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 CT SAE Report Form is maintained in the 
investigator site file.
An exposure during breastfeeding report is not created when a Pfizer drug specifically 
approved for use in breastfeeding women (eg, vitamins) is administered in accord with 
authorized use. However, if the infant experiences an SAE associated with such a drug, the 
SAE is reported together with the exposure during breastfeeding.
8.3.5.3. 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 CT SAE Report Form must be maintained in the 
investigator site file.

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8.3.6. Cardiovascular and Death Events
Not applicable.
8.3.7. Disease-Related Events and/or Disease-Related Outcomes Not Qualifying as AEs 
or SAEs
Not applicable.
8.3.8. Adverse Events of Special Interest
AESIs are examined as part of routine safety data review procedures throughout the clinical 
trial and as part of signal detection processes.
All AESIs must be reported as an AE or SAE following the procedures described in 
Section 8.3.1 through 8.3.4 An AESI is to be recorded as an AE or SAE on the CRF. In 
addition, an AESI that is also an SAE must be reported using the CT SAE Report Form.
8.3.8.1. Lack of Efficacy
This section is not applicable because efficacy is not expected in the study population.
8.3.9. Medical Device Deficiencies
Not applicable. 
8.3.10. 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.
Exposures to the study intervention under study may occur in clinical trial settings, such as 
medication errors.
Safety Event
Recorded on the CRF
Reported on the CT SAE Report 
Form to Pfizer Safety Within 
24 Hours of Awareness
Medication errors All (regardless of whether 
associated with an AE)
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.

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Such medication errors occurring to a study participant are to be captured on the medication 
error page of the CRF, which is a specific version of the AE page.
In the event of a medication dosing error, the sponsor should be notified within 24 hours.
Whether or not the medication error is accompanied by an AE, as determined by the 
investigator, the medication error is recorded on the medication error page of the CRF and, if 
applicable, any associated AE(s), serious and nonserious, are recorded on the AE page of the 
CRF.
Medication errors should be reported to Pfizer Safety within 24 hours on a CT SAE Report 
Form only when associated with an SAE.
8.4. Pharmacokinetics 
8.4.1. Plasma Pharmacokinetics
Blood samples of approximately 4 mL, to provide a minimum of 1.5 mL plasma, will be 
collected for measurement of concentrations of PF-07321332 and ritonavir as specified in the 
SoA. Instructions for the collection and handling of biological samples will be provided in 
the laboratory manual or by the sponsor. The actual date and time (24-hour clock time) of 
each sample will be recorded.
The actual times may change, but the number of samples will remain the same. All efforts 
will be made to obtain the samples at the exact nominal time relative to dosing. Collection of 
samples up to and including 10 hours after dose administration that are obtained within 
10% of the nominal time relative to dosing (eg, ±3 minutes of 30-minute sample; ±6 minutes 
of a 1-hour sample; ±9 minutes of a 1.5-hour sample; ±12 minutes of a 2-hour sample; 
±24 minutes of a 4-hour sample; ±36 minutes of a 6-hour sample; ±48 minutes of a 8-hour
sample) will not be captured as a protocol deviation, as long as the exact time of the 
collection is noted on the source document and the CRF. Collection of samples more than 
10 hours after dose administration that are obtained ≤1 hour away from the nominal time 
relative to dosing will not be captured as a protocol deviation (eg, ±1 hour for a 
12-hour/24-hour/48-hour sample after last dose; pre-dose sample collection window refer to 
SoA), as long as the exact time of the collection is noted on the source document and 
the CRF. This protocol deviation window does not apply to samples to be collected more 
than 10 hours after dose administration at outpatient/follow-up visits with visit windows.
Samples will be used to evaluate the PK of PF-07321332 and ritonavir. As part of 
understanding the PK of the investigational product, samples may also be used to evaluate 
safety or efficacy aspects related to concerns arising during or after the study, for metabolite 
identification and/or evaluation of the bioanalytical method, 
 
Samples collected for measurement of plasma concentrations of PF-07321332 and ritonavir
will be analyzed using a validated analytical method in compliance with applicable SOPs.
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The PK samples must be processed and shipped as indicated in the instructions provided to 
the investigator site to maintain sample integrity. Any deviations from the PK sample 
handling procedure (eg, sample collection and processing steps, interim storage or shipping 
conditions), including any actions taken, must be documented and reported to the sponsor. 
On a case-by-case basis, the sponsor may make a determination as to whether sample 
integrity has been compromised.
Any changes in the timing or addition of time points for any planned study assessments must 
be documented and approved by the relevant study team member and then archived in the 
sponsor and site study files, but will not constitute a protocol amendment. The IRB/EC will 
be informed of any safety issues that require alteration of the safety monitoring scheme or 
amendment of the ICD.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8.5. Genetics
8.5.1. Specified Genetics
Genetics (specified analyses) are not evaluated in this study.
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8.5.2. Retained Research Samples for Genetics
Retained research samples for genetics were not collected. 
8.6. Biomarkers
Biomarkers are not evaluated in this study.
8.6.1. Specified Gene Expression (RNA) Research 
Specified gene expression (RNA) research is not included in this study.
8.6.2. Specified Protein Research 
Specified protein research is not included in this study.
8.6.3. Specified Metabolomic Research 
Specified metabolomic research is not included in this study.
8.6.4. Retained Research Samples for Biomarkers
Retained research samples for biomarkers are not collected in the study. 
8.7. Immunogenicity Assessments
Immunogenicity assessments are not included in this study.
8.8. Health Economics
Health economics/medical resource utilization and health economics parameters are not 
evaluated in this study.
9. STATISTICAL CONSIDERATIONS
Detailed methodology for summary and statistical analyses of the data collected in this study 
is outlined here and further detailed in an SAP, which will be maintained by the sponsor. The 
SAP may modify what is outlined in the protocol where appropriate; however, any major 
modifications of the primary endpoint definitions or their analyses will also be reflected in a 
protocol amendment.
9.1. Statistical Hypotheses
No statistical hypothesis will be tested in this study.

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9.2. Analysis Sets
For purposes of analysis, the following analysis sets are defined:
Participant Analysis Set
Description
Enrolled/Randomly 
assigned to study 
intervention
"Enrolled" means a participant's, or his or her legally 
authorized representative’s, agreement to participate in a 
clinical study following completion of the informed 
consent process and screening. A participant will be 
considered enrolled if the informed consent is not 
withdrawn prior to participating in any study activity after 
screening. Potential participants who are screened for the 
purpose of determining eligibility for the study, but do not 
participate in the study, are not considered enrolled, unless 
otherwise specified by the protocol. 
PK Concentration Analysis 
Set
The PK concentration population is defined as all 
participants assigned to investigational product and treated 
who have at least 1 concentration measured.
PK Parameter Analysis Set
The PK parameter analysis population is defined as all 
participants assigned to investigational product and treated 
who have at least 1 of the PK parameters of primary 
interest measured.
Safety Analysis Set
All participants enrolled to study intervention and who 
take at least 1 dose of study intervention. Participants will 
be analyzed according to the product they actually 
received.
9.3. Statistical Analyses
The SAP will be developed and finalized before any analyses are performed and will 
describe the analyses and 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. Statistical Methods for Pharmacokinetic data 
The PK parameters of PF-07321332 and ritonavir will be listed and descriptively 
summarized by study day, respectively. For AUCs and Cmax, box whisker plots for individual 
participant parameters overlaid with geometric means will be plotted for each analyte. For 
pre-dose concentration, plot of Ctrough over time will be provided for each analyte. The PK 
parameters of PF-07321332 and ritonavir obtained in this study will be compared to the 
corresponding PK data from one or more global completed/ongoing studies which will be 
defined in SAP. The detailed statistical analysis will also be described in SAP. The 
comparative PK data for PF-07321332 and ritonavir may be from different studies depends 
on the specific study design. These results may be reported separately from the clinical study 
report (eg, ethnic sensitivity analysis report, brief document for submission, or other 
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The concentrations of PF-07321332 and ritonavir will be listed and descriptively summarized 
by study day and nominal PK sampling times. For each analyte, individual participant and 
summary profiles (mean and median plots) of the plasma concentration time data will be 
plotted using actual and nominal sampling times, respectively. Additional specifications 
about the tables, listings, and figures will be outlined in the SAP.
9.3.2. Derivation of Pharmacokinetic Parameters Prior to Analysis
The plasma
PK parameters for PF-07321332 and ritonavir will be derived from the 
concentration-time profiles as detailed in Table 1. Actual PK sampling times will be used in 
the derivation of PK parameters. In the case that actual PK sampling times are not available, 
nominal PK sampling times will be used in the derivation of PK parameters.
Table 1.
Plasma 
 PK Parameters
Parameter
Analyte
Day(s)
Definition
Method of Determination
AUClasta
PF-07321332/ritonavir
10
Area under the plasma 
concentration-time 
profile from time 0 to 
the time of the last 
quantifiable 
concentration (Clast)
Linear/Log trapezoidal method.
AUC12
PF-07321332/ritonavir
1
Area under the plasma 
concentration-time 
profile from time 0 to 
time point on 12 hours, 
on Day 1
Linear/Log trapezoidal method.
AUCtau
PF-07321332/ritonavir
10
Area under the plasma
concentration-time 
profile from time 0 to 
the time of the end of 
the dosing interval 
(tau), where 
tau=12 hours
Linear/Log trapezoidal method.
Cmax
PF-07321332/ritonavir
1, 10
Maximum plasma 
concentration during
the dosing interval
Observed directly from data.
Tmax
PF-07321332/ritonavir
1,10
Time for Cmax
Observed directly from data as 
time of first occurrence.
T½a
PF-07321332/ritonavir
10
Terminal elimination 
half-life
Loge(2)/kel, where kel is the 
terminal phase rate constant 
calculated by a linear 
regression of the log-linear 
concentration-time curve. Only 
those data points judged to 
describe the terminal log-linear 
decline will be used in the 
regression.
CL/Fa
PF-07321332/ritonavir
10
Apparent clearance
Dose/AUCtau.
Vz/Fa
PF-07321332/ritonavir
10
Apparent volume of 
distribution
Dose/(AUCtau×kel).
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Table 1.
Plasma 
 PK Parameters
Parameter
Analyte
Day(s)
Definition
Method of Determination
Ctrough
PF-07321332/ritonavir
5, 8, 
10
Pre-dose concentration
Observed directly from data,
pre-dose and 12 hours after last 
dose for Day 10.
Cava
PF-07321332/ritonavir
10
Average concentration 
AUCtau (Day 10) /12 hours.
Raca
PF-07321332
10
Accumulation ratio for 
AUCtau following 
multiple dosing
AUCtau (Day 10) /AUC12 (Day 
1).
Rac,Cmax*
PF-07321332
10
Accumulation ratio for 
Cmax
Cmax (Day 10) /Cmax (Day 1).
PTR*
PF-07321332
10
Peak-to-trough ratio
Cmax (Day 10) /Ctrough (Day 10)漓
at steady state.
 
 
 
 
 
a.
As data permit.
9.3.3. Safety Analyses
All safety analyses will be performed on the safety population.
AEs, ECGs, vital signs, and safety laboratory data will be reviewed and summarized on an 
ongoing basis during the study to evaluate the safety of participants. Any clinical laboratory, 
ECG, BP, and PR abnormalities of potential clinical concern will be described. Safety data 
will be presented in tabular and/or graphical format and summarized descriptively, where 
appropriate.
Medical history and physical examination and neurological examination information, as 
applicable, collected during the course of the study will be considered source data and will 
not be required to be reported, unless otherwise noted. However, any untoward findings 
identified on physical and/or neurological examinations conducted during the active 
collection period will be captured as AEs, if those findings meet the definition of an AE. 
Data collected at screening that are used for inclusion/exclusion criteria, such as laboratory 
data, ECGs, and vital signs, will be considered source data, and will not be required to be 
reported, unless otherwise noted. Demographic data collected at screening will be reported.
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9.4. Interim Analyses
No formal interim analysis will be conducted for this study. As this is an open-label study,
the sponsor may conduct unblinded reviews of the data during the course of the study for the 
purpose of safety assessment, facilitating PK/PD modeling, and/or supporting clinical 
development.
9.5. Sample Size Determination
Approximately 14 participants will be enrolled to ensure approximately 12 participants will 
be evaluable for the primary endpoints. Participants who withdraw from the study may be 
replaced at the discretion of the investigator upon consultation with the sponsor.

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10. SUPPORTING DOCUMENTATION AND OPERATIONAL CONSIDERATIONS
10.1. Appendix 1: Regulatory, Ethical, and Study Oversight Considerations
10.1.1. Regulatory and Ethical Considerations
This study will be conducted in accordance with the protocol and with the following:

Consensus ethical principles derived from international guidelines, including the 
Declaration of Helsinki and CIOMS International Ethical Guidelines;

Applicable ICH GCP guidelines;

Applicable laws and regulations, including applicable privacy laws.
The protocol, protocol amendments, ICD, SRSD(s), and other relevant documents 
(eg, advertisements) must be reviewed and approved by the sponsor, submitted to an IRB/EC 
by the investigator, and reviewed and approved by the IRB/EC before the study is initiated.
Any amendments to the protocol will require IRB/EC approval before implementation of 
changes made to the study design, except for changes necessary to eliminate an immediate 
hazard to study participants.
Protocols and any substantial amendments to the protocol will require health authority 
approval prior to initiation except for changes necessary to eliminate an immediate hazard to 
study participants.
The investigator will be responsible for the following:

Providing written summaries of the status of the study to the IRB/EC annually or 
more frequently in accordance with the requirements, policies, and procedures 
established by the IRB/EC;

Notifying the IRB/EC of SAEs or other significant safety findings as required by 
IRB/EC procedures;

Providing oversight of the conduct of the study at the site and adherence to 
requirements of 21 CFR, ICH GCP guidelines, the IRB/EC, European regulation 
536/2014 for clinical studies (if applicable), European Medical Device Regulation 
2017/745 for clinical device research (if applicable), and all other applicable local 
regulations.
10.1.1.1. Reporting of Safety Issues and Serious Breaches of the Protocol or ICH GCP
In the event of any prohibition or restriction imposed (ie, clinical hold) by an applicable 
regulatory authority in any area of the world, or if the investigator is aware of any new 
information that might influence the evaluation of the benefits and risks of the study 
intervention, Pfizer should be informed immediately.

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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. Informed Consent Process
The investigator or his/her representative will explain the nature of the study, including the 
risks and benefits, to the participant and answer all questions regarding the study. The 
participant should be given sufficient time and opportunity to ask questions and to decide 
whether or not to participate in the trial.
Participants must be informed that their participation is voluntary. Participants 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 study participant is fully informed about the nature 
and objectives of the study, the sharing of data related to the study, and possible risks 
associated with participation, including the risks associated with the processing of the 
participant’s personal data. 
The participant must be informed that his/her personal study-related data will be used by the 
sponsor in accordance with local data protection law. The level of disclosure must also be 
explained to the participant.
The participant must be informed that his/her medical records may be examined by Clinical 
Quality Assurance auditors or other authorized personnel appointed by the sponsor, by 
appropriate IRB/EC members, and by inspectors from regulatory authorities.
The investigator further must ensure that each study participant is fully informed about his or 
her right to access and correct his or her personal data and to withdraw consent for the 
processing of his or her personal data.
The medical record must include a statement that written informed consent was obtained 
before the participant was enrolled in the study and the date on which the written consent was 
obtained. The authorized person obtaining the informed consent must also sign the ICD.
Participants must be reconsented to the most current version of the ICD(s) during their 
participation in the study.
A copy of the ICD(s) must be provided to the participant.
10.1.3. 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.

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Participants’ personal data will be stored at the study site in encrypted electronic and/or paper 
form and will be password-protected or secured in a locked room to ensure that only 
authorized study staff have access. The study site will implement appropriate technical and 
organizational measures to ensure that the personal data can be recovered in the event of 
disaster. In the event of a potential personal data breach, the study site will be responsible for 
determining whether a personal data breach has in fact occurred and, if so, providing breach 
notifications as required by law.
To protect the rights and freedoms of participants with regard to the processing of personal 
data, participants will be assigned a single, participant-specific numerical code. Any 
participant records or data sets that are transferred to the sponsor will contain the numerical 
code; participant names will not be transferred. All other identifiable data transferred to the 
sponsor will be identified by this single, participant-specific code. The study site will 
maintain a confidential list of participants who participated in the study, linking each 
participant’s numerical code to his or her actual identity and medical record 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.
10.1.4. Committees Structure
10.1.4.1. Data Monitoring Committee 
This study will not use a DMC.
10.1.5. Dissemination of Clinical Study Data
Pfizer fulfills its commitment to publicly disclose clinical study results through posting the 
results of studies on www.clinicaltrials.gov (ClinicalTrials.gov), the EudraCT, and/or 
www.pfizer.com, and other public registries in accordance with applicable local 
laws/regulations. In addition, Pfizer reports study results outside of the requirements of local 
laws/regulations pursuant to its SOPs.
In all cases, study results are reported by Pfizer in an objective, accurate, balanced, and 
complete manner and are reported regardless of the outcome of the study or the country in 
which the study was conducted.
www.clinicaltrials.gov
Pfizer posts clinical trial results on www.clinicaltrials.gov for Pfizer-sponsored interventional 
studies (conducted in patients) that evaluate the safety and/or efficacy of a product, 
regardless of the geographical location in which the study is conducted. These results are 
submitted for posting in accordance with the format and timelines set forth by US law.
EudraCT
Pfizer posts clinical trial results on EudraCT for Pfizer-sponsored interventional studies in 
accordance with the format and timelines set forth by EU requirements.

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www.pfizer.com
Pfizer posts public disclosure synopses (CSR synopses in which any data that could be used 
to identify individual participants have been removed) on www.pfizer.com for 
Pfizer-sponsored interventional studies at the same time the corresponding study results are
posted to www.clinicaltrials.gov.
Documents within marketing authorization packages/submissions
Pfizer complies with the European Union Policy 0070, the proactive publication of clinical 
data to the EMA website. Clinical data, under Phase 1 of this policy, includes clinical 
overviews, clinical summaries, CSRs, and appendices containing the protocol and protocol 
amendments, sample CRFs, and statistical methods. Clinical data, under Phase 2 of this 
policy, includes the publishing of individual participant data. Policy 0070 applies to new
marketing authorization applications submitted via the centralized procedure since 
01 January 2015 and applications for line extensions and for new indications submitted via 
the centralized procedure since 01 July 2015.
Data sharing
Pfizer provides researchers secure access to patient-level data or full CSRs for the purposes 
of “bona-fide scientific research” that contributes to the scientific understanding of the 
disease, target, or compound class. Pfizer will make data from these trials available 
24 months after study completion. Patient-level data will be anonymized in accordance with 
applicable privacy laws and regulations. CSRs will have personally identifiable information 
redacted.
Data requests are considered from qualified researchers with the appropriate competencies to 
perform the proposed analyses. Research teams must include a biostatistician. Data will not 
be provided to applicants with significant conflicts of interest, including individuals 
requesting access for commercial/competitive or legal purposes.
10.1.6. Data Quality Assurance
All participant data relating to the study will be recorded on printed or electronic CRF unless 
transmitted to the sponsor or designee electronically (eg, laboratory data). The investigator is 
responsible for verifying that data entries are accurate and correct by physically or 
electronically signing the CRF.
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 clinical study 
report.
The investigator must permit study-related monitoring, audits, IRB/EC review, and 
regulatory agency inspections and provide direct access to source data documents. This 
verification may also occur after study completion. It is important that the investigator(s) and 
their relevant personnel are available during the monitoring visits and possible audits or 
inspections and that sufficient time is devoted to the process.
Monitoring details describing strategy, 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/or 
IQMP 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.
10.1.7. Source Documents
Source documents provide evidence for the existence of the participant and substantiate the 
integrity of the data collected. Source documents are filed at the investigator site.

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Data reported on the CRF or entered in the eCRF that are from source documents must be 
consistent with the source documents or the discrepancies must be explained. The 
investigator may need to request previous medical records or transfer records, depending on 
the study. Also, current medical records must be available.
Definition of what constitutes source data and its origin can be found in the study monitoring 
plan, 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 data) that supports the 
information entered in the CRF.
Study monitors will perform ongoing source data verification to confirm that data entered 
into the CRF by authorized site personnel are accurate, complete, and verifiable from source 
documents; that the safety and rights of participants are being protected; and that the study is 
being conducted in accordance with the currently approved protocol and any other study 
agreements, ICH GCP guidelines, and all applicable regulatory requirements.
10.1.8. Study and Site Start and Closure
The study start date is the date on which the clinical study will be open for recruitment of 
participants.
The first act of recruitment is the date of the first participant’s first visit and will be the study 
start date.
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. 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.

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If the study is prematurely terminated or suspended, the sponsor shall promptly inform the 
investigators, the ECs/IRBs, the regulatory authorities, and any CRO(s) used in the study of 
the reason for termination or suspension, as specified by the applicable regulatory 
requirements. The investigator shall promptly inform the participant and should assure 
appropriate participant therapy and/or follow-up.
Study termination is also provided for in the clinical study agreement. If there is any conflict 
between the contract and this protocol, the contract will control as to termination rights.
10.1.9. Publication Policy
The results of this study may be published or presented at scientific meetings by the 
investigator after publication of the overall study results or 1 year after the end of the study 
(or study termination), whichever comes first. 
The investigator agrees to refer to the primary publication in any subsequent publications,
such as secondary manuscripts, and submits all manuscripts or abstracts to the sponsor 
30 days before submission. This allows the sponsor 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- or Pfizer-intervention 
related information necessary for the appropriate scientific presentation or understanding of 
the study results.
For all publications relating to the study, the investigator will comply with recognized ethical 
standards concerning publications and authorship, including those established by the 
International Committee of Medical Journal Editors.
The sponsor will comply with the requirements for publication of the overall study results 
covering all investigator sites. In accordance with standard editorial and ethical practice, the 
sponsor will support publication of multicenter studies only in their entirety and not as 
individual site data. In this case, a coordinating investigator will be designated by mutual 
agreement.
Authorship of publications for the overall study results will be determined by mutual 
agreement and in line with International Committee of Medical Journal Editors authorship 
requirements. 
If publication is addressed in the clinical study agreement, the publication policy set out in 
this section will not apply.
10.1.10. Sponsor’s Qualified Medical Personnel
The contact information for the sponsor’s appropriately qualified medical personnel for the 
study is documented in the study contact list located in the Investigator Site Master File or 
other supporting study documentation. 

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To facilitate access to appropriately qualified medical personnel for study-related medical 
questions or problems, participants are provided with an Emergency Contact Card (ECC) at 
the time of informed consent. The ECC contains, at a minimum, (a) protocol and study 
intervention identifiers, (b) participant’s study identification number, (c) site emergency 
phone number active 24 hours/day, 7 days per week, and (d) Pfizer Call Center number.
The ECC is intended to augment, not replace, the established communication pathways 
between the investigator, site staff, and study team. The ECC is to be used by healthcare 
professionals not involved in the research study only, as a means of reaching the investigator 
or site staff related to the care of a participant. The Pfizer Call Center number should only be 
used when the investigator and site staff cannot be reached. The Pfizer Call Center number is 
not intended for use by the participant directly; if a participant calls that number directly, he 
or she will be directed back to the investigator site.

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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. 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 2.
Protocol-Required Safety Laboratory Assessments
Hematology
Chemistry
Urinalysis
Other
Hemoglobin
Hematocrit
RBC count
MCV
MCH
MCHC
Platelet count
WBC count
Neutrophils (Abs)
Eosinophils (Abs)
Monocytes (Abs)
Basophils (Abs)
Lymphocytes (Abs)
BUN/Urea and 
creatinine
Glucose (fasting)
Calcium
Sodium
Potassium
Chloride
Carbondioxide 
combining power 
(CO2CP) or
carbondioxide (CO2)
AST, ALT
Total bilirubin
Alkaline phosphatase
Uric acid
Albumin
Total protein
Local Dipstick:
pH
Glucose 
Protein 
Blood 
Ketones
Nitrites
Leukocyte esterase
Laboratory:
Microscopya
COVID-19 testing (PCR)
Urine drug screeningb
Pregnancy test (-hCG)c
aPTT
PT and INR
Fibrinogen
TSH, free T4 and 
antibody (aTPO, ATG)d
At screening only:

FSHe

Hepatitis B surface 
antigen

Hepatitis C 
antibody

HbcAb

HIV
a.
Only if urine dipstick is positive for blood, protein, nitrites, or leukocyte esterase.
b.
At screening and Day -1, as well as at any other time if necessary, at the discretion of the investigator. 
The minimum requirement for drug screening (at screening and Day -1) includes cocaine, THC, 
opiates/opioids, benzodiazepines, and amphetamines (others are site and study specific).
c.
Local urine testing will be standard for the protocol unless serum testing is required by local regulation 
or IRB/EC. Serum or urine -hCG for female participants of childbearing potential (If a urine test 
cannot be confirmed as negative (eg, an ambiguous result), a serum pregnancy test is required).
d.
TSH, free T4 and antibody (aTPO, ATG) tests should be conducted according to SoA requirement.
e.
For confirmation of postmenopausal status only.
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.

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10.3. Appendix 3: Adverse Events: Definitions and Procedures for Recording, 
Evaluating, Follow-Up, and Reporting
10.3.1. Definition of AE
AE Definition

An AE is any untoward medical occurrence in a patient or clinical study 
participant, temporally associated with the use of study intervention, whether or 
not considered related to the study intervention.

Note: An AE can therefore be any unfavorable and unintended sign (including an 
abnormal laboratory finding), symptom, or disease (new or exacerbated) 
temporally associated with the use of study intervention.
Events Meeting the AE Definition

Any abnormal laboratory test results (hematology, clinical chemistry, or 
urinalysis) or other safety assessments (eg, ECG, radiological scans, vital sign 
measurements), including those that worsen from baseline, considered clinically 
significant in the medical and scientific judgment of the investigator. Any 
abnormal laboratory test results that meet any of the conditions below must be 
recorded as an AE:

Is associated with accompanying symptoms;

Requires additional diagnostic testing or medical/surgical intervention;

Leads to a change in study dosing (outside of any protocol-specified dose 
adjustments) or discontinuation from the study, significant additional 
concomitant drug treatment, or other therapy.

Exacerbation of a chronic or intermittent preexisting condition, including either 
an increase in frequency and/or intensity of the condition.

New condition detected or diagnosed after study intervention administration,
even though it may have been present before the start of the study.

Signs, symptoms, or the clinical sequelae of a suspected drug-drug interaction.

Signs, symptoms, or the clinical sequelae of a suspected overdose of either study 
intervention or a concomitant medication. Overdose per se will not be reported as 
an AE or SAE unless it is an intentional overdose taken with possible 
suicidal/self-harming intent. Such overdoses should be reported regardless of 
sequelae.

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Events NOT Meeting the AE Definition

Any clinically significant abnormal laboratory findings or other abnormal safety 
assessments that are associated with the underlying disease, unless judged by the 
investigator to be more severe than expected for the participant’s condition.

The disease/disorder being studied or expected progression, signs, or symptoms 
of the disease/disorder being studied, unless more severe than expected for the 
participant’s condition.

Medical or surgical procedure (eg, endoscopy, appendectomy): the condition that 
leads to the procedure is the AE.

Situations in which an untoward medical occurrence did not occur (social and/or 
convenience admission to a hospital).

Anticipated day-to-day fluctuations of preexisting disease(s) or condition(s) 
present or detected at the start of the study that do not worsen.
10.3.2. Definition of an SAE
An SAE is defined as any untoward medical occurrence that, at any dose, meets one 
or more of the criteria listed below:
a. Results in death
b. Is life-threatening
The term “life-threatening” in the definition of “serious” refers to an event in which 
the participant was at risk of death at the time of the event. It does not refer to an 
event that hypothetically might have caused death if it were more severe.
c.
Requires inpatient hospitalization or prolongation of existing hospitalization
In general, hospitalization signifies that the participant has been admitted (usually 
involving at least an overnight stay) at the hospital or emergency ward for 
observation and/or treatment that would not have been appropriate in the physician’s 
office or outpatient setting. Complications that occur during hospitalization are AEs. 
If a complication prolongs hospitalization or fulfills any other serious criteria, the 
event is serious. When in doubt as to whether “hospitalization” occurred or was 
necessary, the AE should be considered serious.
Hospitalization for elective treatment of a preexisting condition that did not worsen 
from baseline is not considered an AE.

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d. Results in persistent or significant disability/incapacity

The term disability means a substantial disruption of a person’s ability to conduct 
normal life functions.

This definition is not intended to include experiences of relatively minor medical 
significance, such as uncomplicated headache, nausea, vomiting, diarrhea, 
influenza, and accidental trauma (eg, sprained ankle), that may interfere with or 
prevent everyday life functions but do not constitute a substantial disruption.
e.
Is a congenital anomaly/birth defect
f.
Is a suspected transmission via a Pfizer product of an infectious agent, 
pathogenic or non-pathogenic, is considered serious. 
The event may be suspected from clinical symptoms or laboratory findings 
indicating an infection in a participant exposed to a Pfizer product. The terms 
“suspected transmission” and “transmission” are considered synonymous. These 
cases are considered unexpected and handled as serious expedited cases by 
pharmacovigilance personnel. Such cases are also considered for reporting as 
product defects, if appropriate.
g. Other situations:

Medical or scientific judgment should be exercised by the investigator in 
deciding whether SAE reporting is appropriate in other situations, such as 
significant medical events that may jeopardize the participant or may require 
medical or surgical intervention to prevent one of the other outcomes listed in the 
above definition. These events should usually be considered serious.

Examples of such events include invasive or malignant cancers, intensive 
treatment in an emergency room or at home for allergic bronchospasm, blood 
dyscrasias or convulsions that do not result in hospitalization, or development of 
drug dependency or drug abuse.
10.3.3. Recording/Reporting and Follow-Up of AEs and/or SAEs During the Active 
Collection Period
AE and SAE Recording/Reporting
The table below summarizes the requirements for recording AEs on the CRF and for 
reporting SAEs on the CT SAE Report Form to Pfizer Safety throughout the active 
collection period. These requirements are delineated for 3 types of events: (1) SAEs; (2) 
nonserious AEs; and (3) exposure to the study intervention under study during 
pregnancy or breastfeeding, and occupational exposure. 

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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
None
Exposure to the study 
intervention under study 
during pregnancy or 
breastfeeding
All AEs/SAEs associated 
with exposure during 
pregnancy or breastfeeding
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)*
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 non-
participant (not 
involving EDP or EDB).
None. Exposure to a study 
non-participant is not 
collected on the CRF.
The exposure (whether or 
not there is an associated 
AE or SAE) must be
reported.***
*
EDP (with or without an associated AE or SAE): any pregnancy information is reported to 
Pfizer Safety using CT SAE Report Form and EDP Supplemental Form; if the EDP is 
associated with an SAE, then the SAE is reported to Pfizer Safety using the CT SAE 
Report Form. 
** EDB is reported to Pfizer Safety using the CT SAE Report Form which would also include 
details of any SAE that might be associated with the EDB. 
*** Environmental or Occupational exposure: AEs or SAEs associated with occupational 
exposure are reported to Pfizer Safety using the CT SAE Report Form. 

When an AE or SAE occurs, it is the responsibility of the investigator to review 
all documentation (eg, hospital progress notes, laboratory reports, and diagnostic 
reports) related to the event.

The investigator will then record all relevant AE or SAE information in the CRF.

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
It is not acceptable for the investigator to send photocopies of the participant’s 
medical records to Pfizer Safety in lieu of completion of the CT SAE Report 
Form/AE or SAE CRF page.

There may be instances when copies of medical records for certain cases are 
requested by Pfizer Safety. In this case, all participant identifiers, with the 
exception of the participant number, will be redacted on the copies of the medical 
records before submission to Pfizer Safety.

The investigator will attempt to establish a diagnosis of the event based on signs,
symptoms, and/or other clinical information. Whenever possible, the diagnosis 
(not the individual signs/symptoms) will be documented as the AE or SAE.
Assessment of Intensity
The investigator will make an assessment of intensity for each AE and SAE reported 
during the study and assign it to 1 of the following categories: 

Mild: Asymptomatic or mild symptoms; clinical or diagnostic observations only; 
intervention not indicated.

Moderate: Minimal, local or noninvasive intervention indicated; limiting age-
appropriate instrumental ADL. Instrumental ADL refers to preparing meals, 
shopping for groceries or clothes, using the telephone, managing money, etc.

Severe: Severe or medically significant but not immediately life-threatening; 
hospitalization or prolongation of hospitalization indicated; disabling, limiting 
self care ADL. Self care ADL refers to bathing, dressing and undressing, feeding 
self, using the toilet, taking medications, and not bedridden.

An event is defined as “serious” when it meets at least 1 of the predefined 
outcomes as described in the definition of an SAE, NOT when it is rated as severe.
Assessment of Causality

The investigator is obligated to assess the relationship between study intervention 
and each occurrence of each AE or SAE. The investigator will use clinical 
judgment to determine the relationship.

A “reasonable possibility” of a relationship conveys that there are facts, 
evidence, and/or arguments to suggest a causal relationship, rather than a 
relationship cannot be ruled out.

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
Alternative causes, such as underlying disease(s), concomitant therapy, and other 
risk factors, as well as the temporal relationship of the event to study intervention 
administration, will be considered and investigated.

The investigator will also consult the IB and/or product information, for 
marketed products, in his/her assessment.

For each AE or SAE, the investigator must document in the medical notes that 
he/she has reviewed the AE or SAE and has provided an assessment of causality.

There may be situations in which an SAE has occurred and the investigator has 
minimal information to include in the initial report to the sponsor. However, it is 
very important that the investigator always make an assessment of causality 
for every event before the initial transmission of the SAE data to the 
sponsor.

The investigator may change his/her opinion of causality in light of follow-up 
information and send an SAE follow-up report with the updated causality 
assessment.

The causality assessment is one of the criteria used when determining regulatory 
reporting requirements.

If the investigator does not know whether or not the study intervention caused the 
event, then the event will be handled as “related to study intervention” for 
reporting purposes, as defined by the sponsor. In addition, if the investigator 
determines that an SAE is associated with study procedures, the investigator 
must record this causal relationship in the source documents and CRF, and report 
such an assessment in the dedicated section of the CT SAE Report Form and in 
accordance with the SAE reporting requirements.
Follow-Up of AEs and SAEs

The investigator is obligated to perform or arrange for the conduct of 
supplemental measurements and/or evaluations, as medically indicated or as 
requested by the sponsor, to elucidate the nature and/or causality of the AE or 
SAE as fully as possible. This may include additional laboratory tests or 
investigations, histopathological examinations, or consultation with other 
healthcare providers.

If a participant dies during participation in the study or during a recognized 
follow-up period, the investigator will provide Pfizer Safety with a copy of any 
postmortem findings, including histopathology.

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
New or updated information will be recorded in the originally submitted 
documents.

The investigator will submit any updated SAE data to the sponsor within 24 
hours of receipt of the information.
10.3.4. Reporting of SAEs
SAE Reporting to Pfizer Safety via CT SAE Report Form

Facsimile transmission of the CT SAE Report Form is the preferred method to 
transmit this information to Pfizer Safety.

In circumstances when the facsimile is not working, notification by telephone is 
acceptable with a copy of the CT SAE Report Form sent by overnight mail or 
courier service.

Initial notification via telephone does not replace the need for the investigator to 
complete and sign the CT SAE Report Form pages within the designated 
reporting time frames.

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10.4. Appendix 4: Contraceptive and Barrier Guidance
10.4.1. Male Participant Reproductive Inclusion Criteria
Male participants are eligible to participate if they agree to the following requirements 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 reproductive safety risk of the study 
intervention(s):

Refrain from donating sperm.
PLUS either:

Be abstinent from heterosexual intercourse with a female of childbearing potential as 
their preferred and usual lifestyle (abstinent on a long-term and persistent basis) and 
agree to remain abstinent.
OR

Must agree to use contraception/barrier as detailed below:

Agree to use a male condom and should also be advised of the benefit for a 
female partner to use a highly effective method of contraception as a condom may 
break or leak when having sexual intercourse with a woman of childbearing 
potential who is not currently pregnant.

In addition to male condom use, a highly effective method of contraception may be 
considered in WOCBP partners of male participants (refer to the list of highly 
effective methods below in Section 10.4.4).
10.4.2. Female Participant Reproductive Inclusion Criteria
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 definitions below in Section 10.4.3).
OR

Is a WOCBP and using a contraceptive method that is highly effective (with a failure 
rate of <1% per year), with low user dependency, as described below 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). The investigator should evaluate the effectiveness of the 
contraceptive method in relationship to the first dose of study intervention.

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A WOCBP agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during 
this period. 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 in adolescents or athletes) 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. Premenopausal female with 1 of the following.

Documented hysterectomy;

Documented bilateral salpingectomy;

Documented bilateral oophorectomy.
For individuals with permanent infertility due to an alternate 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.
2. 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 old 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 nonestrogen hormonal highly effective contraception methods 

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if they wish to continue their HRT during the study. Otherwise, they 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.
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.
4. Bilateral tubal occlusion (eg, bilateral tubal ligation).
5. Vasectomized partner.

A 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.
6. 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.

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10.5. Appendix 5: 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 Tbili elevations 
(>2 × ULN) by several days or weeks. The increase in Tbili typically occurs while AST/ALT 
is/are still elevated above 3 × ULN (ie, AST/ALT and Tbili values will be elevated within the 
same laboratory sample). In rare instances, by the time Tbili elevations are detected, 
AST/ALT values might have decreased. This occurrence is still regarded as a potential DILI. 
Therefore, abnormal elevations in either AST OR ALT in addition to Tbili that meet the 
criteria outlined below are considered potential DILI (assessed per Hy’s law criteria) cases
and should always be considered important medical events, even before all other possible 
causes of liver injury have been excluded.
The threshold of laboratory abnormalities for a potential DILI case depends on the 
participant’s individual baseline values and underlying conditions. Participants who present 
with the following laboratory abnormalities should be evaluated further as potential DILI 
(Hy’s law) cases to definitively determine the etiology of the abnormal laboratory values:

Participants with AST/ALT and Tbili baseline values within the normal range who 
subsequently present with AST OR ALT values >3 × ULN AND a Tbili value 
>2 × ULN with no evidence of hemolysis and an alkaline phosphatase value 
<2 × ULN or not available.

For participants with baseline AST OR ALT OR Tbili values above the ULN, the 
following threshold values are used in the definition mentioned above, as needed, 
depending on which values are above the ULN at baseline:

Preexisting AST or ALT baseline values above the normal range: AST or ALT 
values >2 times the baseline values AND >3 × ULN; or >8 × ULN (whichever is 
smaller).

Preexisting values of Tbili above the normal range: Tbili level increased from 
baseline value by an amount of at least 1 × ULN or if the value reaches 
>3 × ULN (whichever is smaller).

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Rises in AST/ALT and Tbili separated by more than a few weeks should be assessed 
individually based on clinical judgment; any case where uncertainty remains as to whether it 
represents a potential Hy’s law case should be reviewed with the sponsor. 
The participant should return to the investigator site and be evaluated as soon as possible, 
preferably within 48 hours from awareness of the abnormal results. This evaluation should 
include laboratory tests, detailed history, and physical assessment. 
In addition to repeating measurements of AST and ALT and Tbili for suspected Hy’s law 
cases, additional laboratory tests should include albumin, CK, direct and indirect bilirubin, 
GGT, PT/INR, total bile acids, and alkaline phosphatase. Consideration should also be given 
to drawing a separate tube of clotted blood and an anticoagulated tube of blood for further 
testing, as needed, for further contemporaneous analyses at the time of the recognized initial 
abnormalities to determine etiology. A detailed history, including relevant information, such 
as review of ethanol, acetaminophen/paracetamol (either by itself or as a coformulated 
product in prescription or over-the-counter medications), recreational drug, 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, liver imaging (eg, biliary tract), and collection of serum 
samples for acetaminophen/paracetamol drug and/or protein adduct levels may be warranted. 
All cases demonstrated on repeat testing as meeting the laboratory criteria of AST/ALT and 
Tbili elevation defined above should be considered potential DILI (Hy’s law) cases if no 
other reason for the LFT abnormalities has yet been found. Such potential DILI (Hy’s law) 
cases are to be reported as SAEs, irrespective of availability of all the results of the 
investigations performed to determine etiology of the LFT abnormalities.
A potential DILI (Hy’s law) case becomes a confirmed case only after all results of 
reasonable investigations have been received and have excluded an alternative etiology.

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10.6. Appendix 6: ECG Findings of Potential Clinical Concern
ECG Findings That May Qualify as AEs

Marked sinus bradycardia (rate <40 bpm) lasting minutes.

New PR interval prolongation >280 msec.

New prolongation of QTcF to >480 msec (absolute) or by ≥60 msec from 
baseline.

New-onset atrial flutter or fibrillation, with controlled ventricular response rate: ie, 
rate <120 bpm.

New-onset type I second-degree (Wenckebach) AV block of >30 seconds’
duration.

Frequent PVCs, triplets, or short intervals (<30 seconds) of consecutive 
ventricular complexes.
ECG Findings That May Qualify as SAEs

QTcF prolongation >500 msec.

New ST-T changes suggestive of myocardial ischemia.

New-onset left bundle branch block (QRS >120 msec).

New-onset right bundle branch block (QRS >120 msec).

Symptomatic bradycardia.

Asystole:

In awake, symptom-free participants in sinus rhythm, with documented 
periods of asystole ≥3.0 seconds or any escape rate <40 bpm, or with an 
escape rhythm that is below the AV node. 

In awake, symptom-free participants with atrial fibrillation and bradycardia 
with 1 or more pauses of at least 5 seconds or longer. 

Atrial flutter or fibrillation, with rapid ventricular response rate: rapid = rate 
>120 bpm.

Sustained supraventricular tachycardia (rate >120 bpm) (“sustained” = short 
duration with relevant symptoms or lasting >1 minute).

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
Ventricular rhythms >30 seconds’ duration, including idioventricular rhythm 
(heart rate <40 bpm), accelerated idioventricular rhythm (HR >40 bpm to
<100 bpm), and monomorphic/polymorphic ventricular tachycardia (HR 
>100 bpm (such as torsades de pointes)).

Type II second-degree (Mobitz II) AV block.

Complete (third-degree) heart block.
ECG Findings That Qualify as SAEs

Change in pattern suggestive of new myocardial infarction.

Sustained ventricular tachyarrhythmias (>30 seconds’ duration).

Second- or third-degree AV block requiring pacemaker placement.

Asystolic pauses requiring pacemaker placement.

Atrial flutter or fibrillation with rapid ventricular response requiring 
cardioversion.

Ventricular fibrillation/flutter.

At the discretion of the investigator, any arrhythmia classified as an adverse 
experience.
The enumerated list of major events of potential clinical concern are recommended as “alerts” or 
notifications from the core ECG laboratory to the investigator and Pfizer study team, and not to be 
considered as all inclusive of what to be reported as AEs/SAEs.

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10.7. Appendix 7: Abbreviations
The following is a list of abbreviations that are used in the protocol.
Abbreviation
Term
3CLpro
3C-like protease
Abs
absolute
ADL
activities of daily living
AE
adverse event
AESI
adverse events of special interest
 
 
ALT
alanine aminotransferase
aPTT
activated partial thromboplastin time
AST
aspartate aminotransferase
ATG
antithyroglobulin antibody
aTPO
anti-thyroid peroxidase
AUC
area under the curve
AUC12
area under the plasma concentration-time profile from time 0 to 
time point on 12 hours
AUClast
area under the plasma concentration-time profile from time 0 to the 
time of the last quantifiable concentration (Clast)
AUCtau
area under the plasma concentration-time profile from time 0 to the 
time of the end of the dosing interval (tau), where tau=12 hours
AV
atrioventricular
b-hCG
beta-human chorionic gonadotropin
BID
twice daily
BMI
body mass index
BP
blood pressure
bpm
beats per minute
BUN
blood urea nitrogen
Cav
average concentration
CDK-EPI
Chronic Kidney Disease-Epidemiology Collaboration
CFR
Code of Federal Regulations
CL/F
apparent clearance
CIOMS
Council for International Organizations of Medical Sciences
CK
creatine kinase
Cmax
maximum observed concentration
CO2
carbon dioxide (bicarbonate)
COVID-19
coronavirus disease 2019
CCI
CCI
CCI

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Abbreviation
Term
CRF
case report form
CRO
contract research organization
CRU
clinical research unit
CSR
clinical study report
CT
clinical trial; computerized tomography
Ctrough
trough concentration
CYP
cytochrome P450
CYP3A
cytochrome P450 3A
CYP3A4
cytochrome P450 3A4
CYP3A5
cytochrome P450 3A5
DILI
drug-induced liver injury
DMC
data monitoring committee
dNHBE
differentiated normal human bronchial epithelial
EC
ethics committee
EC90
concentration required for 90% effect
ECC
emergency contact card
ECG
electrocardiogram
eCRF
electronic case report form
EDB
exposure during breastfeeding
EDP
exposure during pregnancy
eGFR
estimated glomerular filtration rate
EMA
European Medicines Agency
EU
European Union
EudraCT
European Clinical Trials Database
FIH
first-in-human
fm
fraction metabolized
FSH
follicle-stimulating hormone
GCP
Good Clinical Practice
GGT
gamma-glutamyl transferase
GLP
Good Laboratory Practice
HBcAb
hepatitis B core antibody
HBsAg 
hepatitis B surface antigen
HCoV-229E
human coronavirus 229E
HCoV-HKU1
human coronavirus HKU1
HCoV-NL63
human coronavirus NL63
HCoV-OC43
human coronavirus OC43
HCV
hepatitis C virus
HCVAb
hepatitis C antibody
HIV
human immunodeficiency virus
HR
heart rate
HRT
hormone replacement therapy

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Abbreviation
Term
IB
investigator’s brochure
ICD
informed consent document
ICH
International Council for Harmonisation
ID
identification
IND
investigational new drug 
INR
international normalized ratio
IP manual
investigational product manual
IPAL
Investigational Product Accountability Log
IRB
institutional review board
IQMP
integrated quality management plan
IV
intravenous
Ki
inhibition constant
LBBB
left bundle branch block
LFT
liver function test
M&E
metabolism and excretion
MAD
multiple ascending dose
MCH
mean corpuscular hemoglobin
MCHC
mean corpuscular hemoglobin concentration
MCV
mean corpuscular volume
MERS
Middle East respiratory syndrome
msec
millisecond
N/A
not applicable
NHP
non-human primate
NOAEL
no-observed-adverse-effect level
NSAE
non-serious adverse event
NYHA
New York Heart Association functional classification
PCR
polymerase chain reaction
PD
pharmacodynamic(s)
PE
physical examination
PK
pharmacokinetic(s)
PR
pulse rate
PT
prothrombin time
PT/INR
prothrombin time/international normalized ratio
PTR
peak-to-trough ratio
PVC
premature ventricular contraction/complex
q12h
every 12 hours
QTc
corrected QT
QTcF
corrected QT (Fridericia method)
QTL
quality tolerance limit
qual
qualitative
Rac
accumulation ratio for AUCtau following multiple dosing

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Abbreviation
Term
Rac Cmax
accumulation ratio for Cmax
RBC
red blood cell
RNA
ribonucleic acid
RR
respiratory rate
SAD
single ascending dose
SAE
serious adverse event
SAP
statistical analysis plan
SARS-CoV-1
severe acute respiratory syndrome coronavirus 1
SARS-CoV-2
severe acute respiratory syndrome coronavirus 2
SCr
serum creatinine
SE
Supratherapeutic Exposure
SoA
schedule of activities
SOP
standard operating procedure
SRSD
single reference safety document
SUSAR
suspected unexpected serious adverse reaction
t½
terminal elimination half-life
T4
Thyroxine
TBili
total bilirubin
TEAE
treatment-emergent adverse event
THC
tetrahydrocannabinol
Tmax
time for Cmax
TSH
thyroid stimulating hormone
ULN
upper limit of normal
US
United States
Vz/F
apparent volume of distribution
WBC
white blood cell
WHO
World Health Organization
WOCBP
woman/women of childbearing potential

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11. REFERENCES
1
WHO Situation Report - 51. 11 March 2020. Available from: 
https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports. 
Accessed: 29 March 2020.
2
Anand K, Ziebuhr J, Wadhwani P, et al. Coronavirus main proteinase (3CLpro) 
structure: basis for design of anti-SARS drugs. Science. 2003;300(5626):1763-7.
3
Hsu A, Granneman GR, Bertz RJ. Ritonavir: Clinical pharmacokinetics and interactions 
with other anti-HIV agents. Clin Pharmacokinet. 1998;35(4):275-91.
4
Ritonavir SmPC. Available from: https://www.ema.europa.eu/en/documents/product-
information/norvir-epar-product-information_en.pdf.
5
Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular 
filtration rate. Ann Intern Med. 2009;150(9):604-12.