Clinical trial NCT04608344
Conditions: Rheumatoid Arthritis
Sponsor: Gilead Sciences
Start date: 2020-11-04; Completion date: 2021-01-13
Enrollment: 27 participants; Allocation: RANDOMIZED; Intervention model: CROSSOVER

Brief summary:
The primary objective of this study is to evaluate the effect of filgotinib on a mixed organic anion transporting polypeptide/cytochrome P450 3A (OATP/CYP3A), OATP/ breast cancer resistance protein (BCRP), and OATP substrates using phenotypic probes.

Detailed description:

Arms: arm 1: Participants will receive atorvastatin (ATV) 40 mg tablet on Day 1, followed by a washout period of 1 day, and then pravastatin (PRA) 40 mg + rosuvastatin (ROS) 10 mg tablets on Day 3 in Treatment A, Period 1. In Treatment B, Period 2 participants will receive filgotinib 200 mg tablet once daily for 11 days, with ATV 40 mg on Day 12 and PRA 40 mg + ROS 10 mg tablets on Day 14. Period 1 and Period 2 will be separated by a washout period of 3 days. arm 2: Participants will receive filgotinib 200 mg tablet once daily for 11 days, with ATV 40 mg on Day 6 and PRA 40 mg + ROS 10 mg tablets on Day 8 in Treatment B, Period 1. In Treatment A, Period 2 participants will receive ATV 40 mg tablet on Day 18, followed by a washout period of 1 day and PRA 40 mg + ROS 10 mg tablets on Day 20. Period 1 and Period 2 will be separated by a washout period of 6 days.
Interventions: intervention 1: Atorvastatin intervention 2: Pravastatin intervention 3: Rosuvastatin intervention 4: Filgotinib
Intervention descriptions: intervention 1: Administered as single dose tablet orally. intervention 2: Administered as single dose tablet orally. intervention 3: Administered as single dose tablet orally. intervention 4: Administered as tablet orally once daily for 11 days.

Protocol documents:
Prot_000.pdf: 
CLINICAL STUDY PROTOCOL
Study Title:
A Phase 1 Study to Evaluate OATP Transporter-Mediated 
Drug-Drug Interactions Between Filgotinib and Statins as Probe 
Drugs in Healthy Participants
Sponsor:
Gilead Sciences, Inc.
333 Lakeside Drive
Foster City, CA 94404
USA
IND Number:
EudraCT Number:
Clinical Trials.gov 
Identifier:
115510
Not Applicable
Not Available
Indication:
Rheumatoid Arthritis 
Protocol ID:
GS-US-417-5937
Contact Information:
The medical monitor name and contact information will be 
provided on the Key Study Team Contact List.
Protocol Version/Date:
Original:
25 Septemeber 2020
This study will be conducted under United States Food and Drug Administration investigational 
new drug (IND) regulations (21 Code of Federal Regulations Part 312).
CONFIDENTIALITY STATEMENT
The information contained in this document, particularly unpublished data, is the property or 
under control of Gilead Sciences, Inc., and is provided to you in confidence as an investigator, 
potential investigator, or consultant, for review by you, your staff, and an applicable 
institutional review board or independent ethics committee. The information is only to be used 
by you in connection with authorized clinical studies of the investigational drug described in 
the protocol. You will not disclose any of the information to others without written 
authorization from Gilead Sciences, Inc., except to the extent necessary to obtain informed 
consent from those persons to whom the drug may be administered.
(r) GILEAU 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 2
25 Septemeber 2020
TABLE OF CONTENTS
TABLE OF CONTENTS ..............................................................................................................................................2
LIST OF IN-TEXT TABLES........................................................................................................................................5
LIST OF IN-TEXT FIGURES ......................................................................................................................................5
PROTOCOL SYNOPSIS ..............................................................................................................................................6
GLOSSARY OF ABBREVIATIONS AND DEFINITION OF TERMS....................................................................13
1.
INTRODUCTION ..............................................................................................................................................16
1.1.
Background ............................................................................................................................................16
1.1.1.
Filgotinib General Information ............................................................................................16
1.1.2.
Preclinical Pharmacology, Pharmacokinetics, and Toxicology............................................17
1.1.3.
Additional Clinical Studies of Filgotinib .............................................................................17
1.1.4.
Atorvastatin..........................................................................................................................17
1.1.5.
Pravastatin............................................................................................................................18
1.1.6.
Rosuvastatin .........................................................................................................................18
1.2.
Rationale for This Study ........................................................................................................................19
1.3.
Rationale for the Dose Selection............................................................................................................20
1.4.
Risk/Benefit Assessment for the Study..................................................................................................21
1.5.
Compliance ............................................................................................................................................21
2.
OBJECTIVES.....................................................................................................................................................22
3.
STUDY DESIGN................................................................................................................................................23
3.1.
Study Design..........................................................................................................................................23
3.2.
Study Drug Administration ....................................................................................................................24
3.3.
Duration of Dosing.................................................................................................................................24
3.4.
Clinic Confinement ................................................................................................................................24
3.5.
Pharmacokinetic Assessments................................................................................................................24
3.5.1.
Plasma Pharmacokinetic Collection.....................................................................................25
3.5.2.
Genomic Sample Collection.................................................................................................25
3.6.
Safety Assessments ................................................................................................................................25
3.7.
End of Study...........................................................................................................................................25
3.8.
Discontinuation Criteria.........................................................................................................................25
3.9.
Source Data............................................................................................................................................26
3.9.1.
Discontinuation ....................................................................................................................26
4.
PARTICIPANT POPULATION.........................................................................................................................27
4.1.
Number of Participants and Participant Selection..................................................................................27
4.1.1.
Participant Replacement.......................................................................................................27
4.2.
Inclusion Criteria....................................................................................................................................27
4.3.
Exclusion Criteria...................................................................................................................................28
5.
STUDY DRUGS.................................................................................................................................................30
5.1.
Randomization, Blinding, and Treatment Codes Access .......................................................................30
5.1.1.
Randomization .....................................................................................................................30
5.1.2.
Blinding................................................................................................................................30
5.2.
Description and Handling of Filgotinib..................................................................................................30
5.2.1.
Formulation..........................................................................................................................30
5.2.2.
Packaging and Labeling .......................................................................................................30
5.2.3.
Storage and Handling...........................................................................................................31


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 3
25 Septemeber 2020
5.3.
Description and Handling of Commercially Available Drugs ...............................................................31
5.4.
Dosage and Administration of Study Drug ............................................................................................31
5.5.
Fasting and Meals ..................................................................................................................................32
5.6.
Dispensing, Accountability, and Disposal or Return of Study Drug......................................................32
5.7.
Concomitant Medications and Other Protocol Restrictions ...................................................................33
5.7.1.
Concomitant Medications.....................................................................................................33
5.7.2.
Other Protocol Restrictions ..................................................................................................33
6.
STUDY ASSESSMENTS...................................................................................................................................35
6.1.
Participant Enrollment and Treatment Assignment................................................................................35
6.2.
Pretreatment Assessments......................................................................................................................41
6.2.1.
Screening Assessments.........................................................................................................41
6.2.2.
Admission Assessments .......................................................................................................41
6.3.
Check-in Assessments............................................................................................................................42
6.4.
Treatment Assessments..........................................................................................................................42
6.5.
Pharmacokinetic Assessments................................................................................................................42
6.5.1.
Plasma PK Collection...........................................................................................................42
6.6.
Safety Assessments ................................................................................................................................43
6.6.1.
Electrocardiogram Assessment ............................................................................................43
6.6.2.
Physical Examination...........................................................................................................43
6.6.3.
Vital Signs............................................................................................................................44
6.6.4.
Body Mass Index..................................................................................................................44
6.6.5.
Clinical Laboratory Tests/Assessments................................................................................44
6.6.6.
Creatinine Clearance ............................................................................................................45
6.6.7.
Adverse Events/Concomitant Medications/Protocol Restrictions........................................45
6.7.
Posttreatment Assessments ....................................................................................................................45
6.8.
Assessments for Early Discontinuation from Study...............................................................................45
7.
ADVERSE EVENTS AND TOXICITY MANAGEMENT...............................................................................46
7.1.
Definitions of Adverse Events and Serious Adverse Events..................................................................46
7.1.1.
Adverse Events.....................................................................................................................46
7.1.2.
Serious Adverse Events........................................................................................................46
7.1.3.
Study Drugs and Gilead Concomitant Therapy Special Situations Reports.........................47
7.2.
Assessment of Adverse Events and Serious Adverse Events.................................................................48
7.2.1.
Assessment of Causality for Study Drugs and Procedures...................................................48
7.2.2.
Assessment of Severity ........................................................................................................48
7.3.
Investigator Reporting Requirements and Instructions ..........................................................................49
7.3.1.
Requirements for Collection Prior to Study Drug Initiation.................................................49
7.3.2.
Adverse Events.....................................................................................................................49
7.3.3.
Serious Adverse Events........................................................................................................49
7.3.4.
Study Drug Special Situations Reports ................................................................................49
7.3.5.
Concomitant Therapy Reports..............................................................................................49
7.4.
Reporting Process for Serious Adverse Events and Special Situation Reports......................................50
7.4.1.
Serious Adverse Event Reporting Process ...........................................................................50
7.4.2.
Special Situations Reporting Process ...................................................................................51
7.5.
Gilead Reporting Requirements.............................................................................................................52
7.6.
Clinical Laboratory Abnormalities and Other Abnormal Assessments as Adverse Events or 
Serious Adverse Events..........................................................................................................................53
7.7.
Toxicity Management ............................................................................................................................53
7.7.1.
Grades 1 and 2 Laboratory Abnormality or Clinical Event..................................................53
7.7.2.
Grades 3 Laboratory Abnormality or Clinical Event ...........................................................53
7.7.3.
Grades 4 Laboratory Abnormality or Clinical Event ...........................................................54
CCI


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 4
25 Septemeber 2020
8.
STATISTICAL CONSIDERATIONS................................................................................................................55
8.1.
Analysis Objectives and Endpoints........................................................................................................55
8.1.1.
Analysis Objectives..............................................................................................................55
8.1.2.
Primary Endpoint .................................................................................................................55
8.1.3.
Secondary Endpoint .............................................................................................................55
8.2.
Planned Analyses ...................................................................................................................................55
8.2.1.
Final Analysis.......................................................................................................................55
8.3.
Analysis Conventions.............................................................................................................................56
8.3.1.
Analysis Sets ........................................................................................................................56
8.3.2.
Data Handling Conventions .................................................................................................56
8.4.
Demographic Data and Baseline Characteristics ...................................................................................56
8.5.
Safety Analysis.......................................................................................................................................57
8.5.1.
Extent of Exposure...............................................................................................................57
8.5.2.
Adverse Events.....................................................................................................................57
8.5.3.
Laboratory Evaluations ........................................................................................................57
8.5.4.
Other Safety Evaluations......................................................................................................57
8.6.
Pharmacokinetic Analysis......................................................................................................................57
8.7.
Sample Size............................................................................................................................................58
9.
RESPONSIBILITIES..........................................................................................................................................59
9.1.
Investigator Responsibilities ..................................................................................................................59
9.1.1.
Good Clinical Practice..........................................................................................................59
9.1.2.
Financial Disclosure.............................................................................................................59
9.1.3.
Institutional Review Board Review and Approval...............................................................59
9.1.4.
Informed Consent.................................................................................................................59
9.1.5.
Study Files and Retention of Records ..................................................................................60
9.1.6.
Case Report Forms...............................................................................................................61
9.1.7.
Investigator Inspections........................................................................................................62
9.1.8.
Protocol Compliance............................................................................................................62
9.2.
Sponsor Responsibilities ........................................................................................................................62
9.2.1.
Protocol Modifications.........................................................................................................62
9.2.2.
Study Report and Publications .............................................................................................62
9.3.
Joint Investigator/Sponsor Responsibilities ...........................................................................................63
9.3.1.
Payment Reporting...............................................................................................................63
9.3.2.
Access to Information for Monitoring..................................................................................63
9.3.3.
Access to Information for Auditing or Inspections ..............................................................63
9.3.4.
Study Discontinuation..........................................................................................................63
10.
REFERENCES ...................................................................................................................................................64
11.
APPENDICES ....................................................................................................................................................65
Appendix 1.
Investigator Signature Page....................................................................................................66
Appendix 2.
Pregnancy Precautions, Definition for Female of Childbearing Potential, and 
Contraceptive Requirements...................................................................................................67
Appendix 3.
Management of Clinical and Laboratory Adverse Events......................................................70
Appendix 4.
Common Terminology Criterial for Adverse Events (CTCAE) Grading Scale v5.0 .............71


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 5
25 Septemeber 2020
LIST OF IN-TEXT TABLES
Table 6-1.
Schedule of Assessments (Sequence AB) ..............................................................................36
Table 6-2.
Schedule of Assessments (Sequence BA) ..............................................................................38
LIST OF IN-TEXT FIGURES
Figure 3-1.
Study Schema – Sequence AB ...............................................................................................23
Figure 3-2.
Study Schema – Sequence BA ...............................................................................................24


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 6
25 Septemeber 2020
PROTOCOL SYNOPSIS
Gilead Sciences, Inc.
333 Lakeside Drive
Foster City, CA 94404
USA
Study Title:
A Phase 1 Study to Evaluate OATP Transporter-Mediated 
Drug-Drug Interactions Between Filgotinib and Statins as Probe 
Drugs in Healthy Participants
IND Number:
EudraCT Number:
Clinical Trials.gov 
Identifier:
115510
Not Applicable
Not Available
Study Centers 
Planned:
Single Phase 1 center in the United States (US)
Objectives:
The primary objective of this study is as follows:

To evaluate the effect of filgotinib on a mixed organic anion 
transporting polypeptide/cytochrome P450 3A (OATP/CYP3A), 
OATP/breast cancer resistance protein (BCRP), and OATP 
substrates using phenotypic probes
The secondary objective of this study is as follows:

To evaluate the safety and tolerability of multiple filgotinib doses 
administered alone or in combination with probe drugs
Study Design:
Phase 1, randomized, two-way cross-over, open-label, single and 
multiple dose, single center study
Number of 
Participants
Planned:
30 participants (for 26 evaluable)
Target Population:
Healthy nonpregnant, nonlactating female and surgically sterile male 
participants, aged 18-55, inclusive
Duration of 
Dosing:
13 days
Study Duration:
Up to 27 days (not including screening window) for Sequence AB
Up to 30 days (not including screening window) for Sequence BA


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 7
25 Septemeber 2020
Diagnosis and 
Main Eligibility 
Criteria:
Eligible participants will be surgically sterile male and nonpregnant, 
nonlactating female participants, with body mass index (BMI) of 
≥19 and ≤30 kg/m2, normal 12-lead electrocardiogram (ECG), 
normal renal function, and no significant medical history. 
Participants will also be in good general health as determined by the 
investigator at the screening evaluation performed no more than 
28 days prior to the scheduled first dose.
Study Procedures/
Frequency:
Following completion of screening and admission assessments 
(Day 1), eligible participants will be randomized the evening of 
Day 1 to receive 1 of 2 treatment sequences starting on Day 1:
The study treatments are as follows:
OATP/CYP3A substrate: Atorvastatin (ATV) 40 mg
OATP substrate: Pravastatin (PRA) 40 mg
OATP/BCRP substrate: Rosuvastatin (ROS) 10 mg
Pravastatin/Rosuvastatin (PRA/ROS) will be coadministered as a 
probe cocktail
Treatment A: Single dose of ATV 40 mg, followed by a washout 
period of one day or a single dose of the PRA 40 mg/ROS 10 mg
cocktail 
Treatment B: Filgotinib 200 mg administered once daily for 11 
days, with a single dose of ATV 40 mg administered on the sixth day 
followed by a single dose of PRA 40 mg/ROS 10 mg cocktail 
administered on the eighth day
Sequence
Days
AB
Period 1
Period 2
1
2
3
4-6
7-
11
12
13
14
15-
17
ATV
WO
PRA 
+ 
ROS
WO
FIL
FIL +
ATV
FIL
FIL 
+ 
PRA 
+ 
ROS
FIL
BA
Period 1
Period 2
1-5
6
7
8
9-
11
12-
17
18
19
20
FIL
FIL + 
ATV
FIL
FIL 
+ 
PRA 
+ 
ROS
FIL
WO
ATV
WO
PRA 
+ 
ROS
FIL  filgotinib; ATV  atorvastatin; PRA  pravastatin; ROS  rosuvastatin; 
WO
washout


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 8
25 Septemeber 2020
Study Visits and Confinement
Following screening and admission assessments, eligible participants 
will be confined to the study center beginning Day 1 until the 
completion of assessments on Day 17 (Sequence AB) or Day 23 
(Sequence BA). All participants will be contacted by 
telephone 7 (± 2) days after last dose for follow up (ie, on Day 24 
[± 2] for Sequence AB or Day 27 [± 2] for Sequence BA).
Study Drug Administration
All study treatments will be administered at approximately the same 
time each day with 240 mL of water following an overnight fast 
(no food or drinks except water) for at least 10 hours. On 
non-intensive Pharmacokinetic (PK) days, participants will continue 
to fast for 2 hours after dosing postdose relative to study drug 
dosing.
On the days of intensive PK sampling, study treatments will be 
administered in the morning following an overnight fast (no food or 
drinks except water for at least 10 hours). Participants will continue 
to fast until after collection of the 4-hour PK sample, relative to 
study drug dosing. Additionally, participants will be restricted from 
water consumption 1 hour before and until 2 hours after dosing, 
except for the 240 mL given with the study treatment. After 
collection of the 4-hour PK sample, participants will be provided 
with a standardized meal.
Pharmacokinetic Assessments
Intensive plasma PK sampling will occur relative to dosing of study 
drug at the following time points for each study day as specified 
below:
Sequence AB:

Days 1 and 12: 0 (pre-dose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 
8, 10, 12, 16, 24, 36, and 48 hours postdose

Days 3 and 14: 0 (pre-dose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 
12, 16, 24, 48, and 72 hours postdose
Sequence BA: 

Days 6 and 18: 0 (pre-dose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 
8, 10, 12, 16, 24, 36, and 48 hours postdose

Days 8 and 20: 0 (pre-dose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 
12, 16, 24, 48, and 72 hours postdose


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 9
25 Septemeber 2020
Plasma concentrations of ATV, PRA, and ROS will be determined 
and PK evaluated. Plasma concentrations of filgotinib and its 
metabolite (GS-829845) may be analyzed. Plasma concentrations of 
metabolites of probe drugs or filgotinib may be analyzed, if 
applicable.
Safety Assessments
Assessment of adverse events (AEs) and concomitant medications 
will continue throughout the study. All clinical and clinically 
significant laboratory toxicities will be managed according to 
uniform guidelines detailed in protocol Appendix 4.
The schedules of assessments are as follows:
Sequence AB
Complete physical exam: screening, admission (Day 1), Day 9, 17,
and at the early termination (ET) visit, if applicable. 
Symptom-driven physical exam: Daily during confinement as needed 
based on reported signs and symptoms
Vital signs (blood pressure, heart rate, respiration rate, and body 
temperature): Screening, Admission (Day 1), Days 1, 3, 6, 7, 10, 
12, 14, 15, 17, and at the ET visit, if applicable
Height: Screening
Weight: Screening, Admission (Day 1), Days 7, 14, 17, and at the 
ET visit, if applicable
12-lead ECG: Screening 
Hepatitis B virus (HBV), hepatitis C virus (HCV), human 
immunodeficiency virus type 1 testing (HIV-1): Screening
Follicle Stimulating Hormone (FSH): Screening
Urine drug and alcohol assessments: Screening and Admission 
(Day 1)
Thyroid-stimulating hormone (TSH): Screening
Serum pregnancy test (female of childbearing potential only): 
Screening, Admission (Day
1), (Day 17), and at the ET visit, if 
applicable
Urine pregnancy test: Admission (Day 1), Day 7 
Clinical laboratory tests (hematology, chemistry, creatine 
phosphokinase [CPK], and urinalysi): Screening, Admission 
(Day 1), Days 1, 3, 6, 7, 12, 13, 14, 15, 17, and at the ET visit, if 
applicable


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 10
25 Septemeber 2020
Calculated Creatinine Clearance (CLcr): Screening, Admission 
(Day 1), Days 7, 14, 17, and at the ET visit, if applicable
Sequence BA
Complete physical exam: Screening, Admission (Day 1), Days 9,
23, and at the ET visit, if applicable 
Symptom-driven physical exam: Daily during confinement as needed 
based on reported signs and symptoms
Vital signs (blood pressure, heart rate, respiration rate, and body 
temperature): Screening, Admission (Day 1), Days 1, 3, 6, 7, 8, 9, 
11, 18, 20, 23 and at the ET visit, if applicable
Height: Screening
Weight: Screening, Admission (Day 1), Days 7, 11, 18, 23, and at 
the ET visit, if applicable
12-lead ECG: Screening 
Hepatitis B virus (HBV), hepatitis C virus (HCV), human 
immunodeficiency virus type 1 testing (HIV-1): Screening
Follicle Stimulating Hormone (FSH): Screening
Urine drug and alcohol assessments: Screening and Admission 
(Day 1)
Thyroid-stimulating hormone (TSH): Screening
Serum pregnancy test (female of childbearing potential only): 
Screening, Admission (Day 1), Days 7 and 20 and at the ET visit, if 
applicable
Urine pregnancy test: Admission (Day 1), Day 7 
Clinical laboratory tests (hematology, chemistry, CPK, and 
urinalysis): Screening, Admission (Day 1), Days 1, 5, 6, 7, 8, 9, 11, 
18, 20, 23 and at the ET visit, if applicable
Calculated Creatinine Clearance (CLcr): Screening, Admission 
(Day 1), Days 7, 11, 18, and 23, and at the ET visit, if applicable
All Sequences
Coronavirus Disease 2019 (COVID-19) Real-Time Reverse 
Transcriptase-Polymerase Chain Reaction (RT-PCR) Test: RT-PCR 
testing will be conducted and reviewed per site specific policy at 
Screening, Admission, and as needed during the study. Alternatively, 
a comparable test may be used after consultation with the Sponsor.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 11
25 Septemeber 2020
Genomic Sample Collection
A single blood sample for genomic testing and genotyping to 
identify polymorphisms of drug transporters (eg, OATP1B1) will be 
obtained for all participants and may be analyzed, as applicable. This 
sample should be collected on Day 1, but may be collected at any 
time during the study, if necessary.
Test Product, Dose, 
and Mode of 
Administration:
Treatment B: Filgotinib 200 mg administered once daily with a 
single dose of ATV 40 mg or a single dose of PRA 40 mg/ROS
10 mg cocktail. All agents should be administered in the morning 
under fasted conditions.
Reference Therapy, 
Dose, and Mode of 
Administration:
Treatment A: Single dose of ATV 40 mg or a single dose of the 
PRA 40 mg/ROS 10 mg cocktail administered in the morning under 
fasted conditions.
Criteria for 
Evaluation:
Safety:
Safety will be assessed during the study through the documentation 
of AEs, and by clinical laboratory tests, physical examinations, vital 
signs, and 12-lead safety ECGs at various time points during the 
study.
Efficacy:
Not applicable
Pharmacokinetics:
The following plasma PK parameters will be calculated for ATV, 
PRA, and ROS, as applicable: AUClast, AUCinf, %AUCexp, Cmax, Clast, 
Tmax, Tlast, t1/2, CL/F, λz, and Vz/F.
PK parameters for other analytes may be determined.
Statistical Methods:
Pharmacokinetics:
Plasma concentrations and PK parameters will be listed and 
summarized using descriptive statistics by treatment. 
An analysis of variance (ANOVA) using a mixed-effects model with 
treatment, and sequence as fixed effects and participant as a random 
effect will be fitted to the natural logarithmic transformation of PK 
parameters (AUClast, AUCinf, and Cmax) for each analyte. Two-sided 
90% CIs will be calculated for the ratios of geometric least-squares 
means (GLSMs) of primary PK parameters between test (Treatment 
B) versus reference (Treatment A) treatments. Lack of PK 
interaction between the test and reference treatments will be 
concluded if the 90% CIs for the GLSM ratios are contained within 
the 0.70 and 1.43 range for ATV, PRA, and ROS AUC and Cmax. 
Additional analyses may be performed if useful and appropriate. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 12
25 Septemeber 2020
Safety: 
The AE data will be listed by participant. Treatment-emergent AEs, 
serious adverse events (SAEs), and AEs leading to permanent study 
drug discontinuation will be summarized by treatment, system organ 
class, and preferred term using the current version of the Medical 
Dictionary for Regulatory Activities (MedDRA).
Listings of individual participant laboratory results will be provided. 
Laboratory results and change from predose values for selected lab 
tests will be summarized by treatment sequence at scheduled visits. 
The incidence of treatment-emergent laboratory abnormalities will 
be summarized by treatment.
Vital signs and ECG data will be summarized by treatment/treatment 
sequence.
Sample Size:
With 26 evaluable participants the estimated two-sided 90% CI of 
the GLSM ratio of test versus reference treatments, with regards to 
AUCinf, AUClast, and Cmax, will be within [70%, 143%] with ≥85% 
probability, if the true GLSM ratio is 1.0. This is assuming a 
standard deviation (SD) of differences of no more than 0.569 on a 
natural logarithm scale, supported by PK data from Study 
GS-US-402-2102. With 4 participants for overage, a total sample 
size of 30 participants will be required.
This study will be conducted in accordance with the guidelines of Good Clinical Practice 
(GCP) including archiving of essential documents.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 13
25 Septemeber 2020
GLOSSARY OF ABBREVIATIONS AND DEFINITION OF TERMS
%AUCexp
percentage of AUC extrapolated between AUClast and AUCinf
AE
adverse event
AE 
adverse events 
eCRF
electronic case report form
ALT
alanine aminotransferase
ANOVA
analysis of variance
AS
ankylosing spondylitis
AST
aspartate aminotransferase
ATV
atorvastatin
AUC
area under the concentration versus time curve
AUCinf
area under the concentration versus time curve extrapolated to infinite time, calculated 
as AUClast + (Clast/z)
AUClast
area under the concentration versus time curve from time zero to the last quantifiable 
concentration
BCRP
breast cancer resistance protein
BMI
body mass index
CD
Crohn’s Disease 
CI
confidence interval
CK
creatine kinase
Clast
last observed quantifiable concentration of the drug
CLcr
creatinine clearance
Cmax
maximum observed concentration of drug
COVID-19 RT-PCR
a real-time reverse transcription polymerase chain reaction (rTT-PCR) test for the 
qualitative detection of nucleic acid from SARS-CoV-2
CPK
creatine phosphokinase
CTCAE
Common Terminology Criteria for Adverse Events
DDI
drug-drug interaction
DNA
deoxyribonucleic acid
ECG
electrocardiogram
eCRF
electronic case report form
EDC
electronic data capture
EMA
European Medicines Agency
ET
early termination
FDA
Food and Drug Administration
FSH
follicle-stimulating hormone
GCP
Good Clinical Practice
Gilead
Gilead Sciences
GLPS
Global Patient Safety
GLSM
geometric least-squares mean


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 14
25 Septemeber 2020
HBV
hepatitis B virus
HCV
hepatitis C virus
HIV-1
human immunodeficiency virus type 1
HMG-CoA
3-hydroxy-3-methylglutaryl-coenzyme A
IB
investigator’s brochure
IBD
inflammatory bowel disease
ICF
informed consent form
ICH
International Council for Harmonisation (of Technical Requirements for 
Pharmaceuticals for Human Use) 
IC50
half maximal inhibitory concentration
IND
investigational new drug
IRB
institutional review board
JAK
Janus kinase
z
terminal elimination rate constant, estimated by linear regression of the terminal 
elimination phase of the log concentration of drug versus time curve of the drug
LDL
low-density lipoprotein
LLOQ
lower limit of quantitation
Macrogol/PEG 3350
based oral osmotic laxative promotes the retention of water in the bowel
MedDRA
Medical Dictionary for Regulatory Activities
OATP
organic anion transporting polypeptide
OATP/CYP3A
organic anion transporting polypeptide/cytochrome P450 3A
PCR
polymerase chain reaction
PK
pharmacokinetic(s)
PRA
Pravastatin
PRA/ROS
Pravastatin/Rosuvastatin
PsA
psoriatic arthritis
PT
preferred term
QT syndrome
a disorder of the heart’s electrocial activity
RA
rheumatoid arthritis
ROS
Rosuvastatin
SAE
serious adverse event
SD
standard deviation
SDV
source data verification
SOC
system organ class
SOP
standard operating procedure
SSRs
Special situation reports
STAT
signal transducer and activator of transcription
SUSAR
suspected unexpected serious adverse reaction
t1/2
estimate of the terminal elimination half-life of the drug, calculated by dividing the 
natural log of 2 by the terminal elimination rate constant (z)
TEAE
treatment-emergent adverse event


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 15
25 Septemeber 2020
TSH
thyroid-stimulating hormone
TYKs
tyrosine kinases
UC
ulcerative colitis
US
United States
Vz/F
apparent volume of distribution of the drug


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 16
25 Septemeber 2020
1.
INTRODUCTION
1.1.
Background
Over the last decade changes in rheumatoid arthritis (RA) treatment strategies, accompanied by 
advances in drug development and the addition of targeted biological therapies, have greatly 
improved the outcomes for patients with RA. Despite these developments, therapeutic challenges 
remain. The current conventional and biological disease-modifying anti-rheumatic drugs 
(DMARDs) may be ineffective or produce only partial responses in some patients and are 
associated with significant safety and tolerability concerns. There is an unmet medical need for 
simple, orally administered therapies with novel mechanisms of action that can effectively 
improve the disease course while being safe and well tolerated. 
Janus kinases (JAKs) are intracellular cytoplasmic tyrosine kinases (TYKs) that transduce 
cytokine signaling from membrane receptors to the nucleus of cells. JAK/signal transducer and 
activator of transcription (STAT) signaling pathways are evolutionarily conserved and 
ubiquitous in humans and animals and are activated by a variety of cytokines, growth factors, 
and other chemical messengers.
Filgotinib is a potent JAK inhibitor that is highly selective for JAK1. The main metabolite of 
filgotinib, GS-829845, is pharmacologically active and is also a selective inhibitor of JAK1. It is 
expected that targeted inhibition of JAK1 will retain the clinical efficacy, while improving upon 
the safety profile of the less selective JAK family inhibitors. To date, JAK inhibitors approved 
for the treatment of RA include tofacitinib, baricitinib, and upadacitinib. Filgotinib is currently in 
development for the treatment of multiple inflammatory conditions including RA, psoriatic 
arthritis (PsA), ankylosing spondylitis (AS), ulcerative colitis (UC), Crohn’s disease (CD), and 
uveitis. 
1.1.1.
Filgotinib General Information
Filgotinib (GS-6034, formerly GLPG0634) is an orally administered potent and selective 
inhibitor of JAK1. JAK inhibitors block the signaling of various cytokines, growth factors, and 
hormones, including the pro-inflammatory cytokine IL-6. Four different types of JAKs are 
known, JAK1, JAK2, JAK3, and TYK2 which co-interact with different sets of membrane 
receptors. Inhibition of JAKs is a promising therapeutic option for a range of inflammatory 
conditions including RA, UC, and CD. The compound has shown good preliminary efficacy in 
participants with PsA {Mease 2018}, AS {van der Heijde 2018} and CD in Phase 2 studies 
(filgotinib Investigator’s Brochure [IB] Edition 15, dated 03 September 2020). In Phase 3 RA 
studies, filgotinib was generally well tolerated for the duration of the studies (24 weeks in 
GS-US-417-0302 and 52 weeks in GS-US-417-0301 and GS-US-417-0303) (filgotinib IB). 
Filgotinib is currently under assessment in ongoing Phase 3 PsA, UC, CD studies 
(clinicaltrials.gov). Additionally, filgotinib is currently under review by regulatory agencies for 
the treatment of adults who are living with moderate-to-severe RA. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 17
25 Septemeber 2020
For further information on filgotinib, refer to the IB, including information on the following:

Nonclinical pharmacokinetic (PK) and in vitro metabolism

Nonclinical pharmacology and toxicology

Clinical experience
1.1.2.
Preclinical Pharmacology, Pharmacokinetics, and Toxicology
For detailed information on all supporting preclinical data for filgotinib, please refer to the IB.
1.1.3.
Additional Clinical Studies of Filgotinib
An overview of clinical studies conducted with filgotinib is available in the IB.
As of 30 June 2020, 41 Phase 1, 2, and 3 clinical studies have been conducted/are ongoing in 
which 394 healthy volunteers or special populations (15 subjects with renal impairment and 
10 subjects with hepatic impairment), 4126 subjects with RA, an estimated 1121 subjects with 
CD, an estimated 1334 subjects with UC, 94 subjects with AS, an estimated 178 subjects with 
PsA, and an estimated 111 subjects with other inflammatory diseases have been dosed with 
filgotinib. Subjects in long-term extension (LTE) studies (Studies GLPG0634-CL-205, 
GS-US-417-0304, GS-US-419-3896, and GLPG0634-CL-225) were not included in subject 
numbers in order to eliminate double-counting. Information About Atorvastatin, Pravastatin,
and Rosuvastatin
1.1.4.
Atorvastatin
Atorvastatin (ATV) is a synthetic lipid-lowering agent that works via inhibition of 
3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme catalyzes the 
conversion of HMG-CoA to mevalonate, an early and rate-limiting step in cholesterol 
biosynthesis. Atorvastatin 40 mg is representative of the middle of the recommended ATV dose 
range used in clinical practice (10 mg to 80 mg). Drug interactions resulting in significant 
changes in ATV exposure generally involve inhibition of cytochrome P450 (CYP) 3A4 
(eg, cyclosporine) (Elsby et al 2012), and filgotinib has been show to not inhibit CYP34A4 in 
vivo GLPG0634-CL-103; accordingly, large increases in ATV exposure are not expected when 
administered with filgotinib, which does not inhibit CYP enzymes. 
Atorvastatin, as well as some of its metabolites, are pharmacologically active in humans. The 
liver is the primary site of action and the principal site of cholesterol synthesis and low-density 
lipoprotein (LDL) clearance. Atorvastatin has 14% bioavailability via oral administration and is 
rapidly absorbed after oral administration in the fasted state; maximum plasma concentrations 
occur within 1 to 2 hours. Food slows the rate of absorption. Hepatic CYP3A4 is the major 
metabolic pathway. Elimination is mostly through the biliary route, with 1-2% also being 
excreted renally. Mean plasma elimination half-life of ATV in humans is approximately 
14 hours, but the half-life of inhibitory activity for HMG-CoA reductase is 20 to 30 hours due to 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 18
25 Septemeber 2020
the contribution of active metabolites. Atorvastatin 10 to 80 mg once daily is the recommended 
dose range used in clinical practice to treat hyperlipidemia or to prevent cardiovascular disease.
Further information regarding ATV is available in the prescribing information.
1.1.5.
Pravastatin
Pravastatin (PRA) is a HMG-CoA reductase inhibitor used in patients with elevated cholesterol 
and with a risk of cardiovascular disease. In this study, PRA 40 mg (1 40 mg tablet), will be 
administered as a single dose to healthy participants to assess organic anion transporting 
polypeptide (OATP) activity in the presence and absence of filgotinib. The sensitivity of PRA as 
an in vivo probe for assessing OATP activity at this dose has been previously established 
{Giacomini 2010}.
After oral administration, peak plasma PRA concentrations were observed 1 to 1.5 hours 
postdose. Based on urinary recovery of total radiolabeled drug, the average oral absorption of 
PRA is 34% and absolute bioavailability is 17%. Food in the gastrointestinal tract reduces 
systemic bioavailability of PRA. Pravastatin is not extensively protein bound (50%). The major 
biotransformation pathways of PRA are 1) isomerization to 6-epi PRA and the 
3α-hydroxyisomer of PRA and 2) enzymatic ring hydroxylation. Approximately 20% of a 
radiolabeled oral dose is excreted in urine and 70% in the feces. After intravenous administration 
of radiolabeled PRA to healthy participants, approximately 47% of total body clearance was via 
renal excretion and 53% by non-renal routes (eg, biliary excretion and biotransformation). 
Following single dose oral administration of 14C-PRA, the radioactive elimination t1/2 for PRA is 
1.8 hours in humans. Pravastatin is indicated for hyperlipidemia and for cardiovascular disease 
prevention, the recommended starting dose is 40 mg once daily, and to use 80 mg dose only for 
patients not reaching LDL-Cholesterole goal with 40 mg. 
Further information regarding PRA is available in the prescribing information.
1.1.6.
Rosuvastatin
Rosuvastatin (ROS), is a HMG-CoA reductase inhibitor used in patients with elevated 
cholesterol and with a risk of cardiovascular disease. In this study, ROS 10 mg (1 10 mg tablet) 
will be administered as a single dose to healthy participants to collectively assess 
OATP1B1/1B3 and breast cancer resistance protein (BCRP) activity in the presence and absence 
of filgotinib {Chu 2018, Giacomini 2010}.
The relative contribution of OATP and BCRP in determining in vivo ROS disposition is not 
known. However, emerging data on the significance of SLCO1B1 polymorphisms and associated 
statin-induced myopathy provides compelling evidence on the importance of OATP in ROS PK
{Elsby 2012, Meyer zu Schwabedissen 2009, Neuvonen 2010, Pasanen 2007}. Collectively, use 
of both PRA and ROS as probes in this study will allow for a better understanding and/or 
discrimination of the effects of filgotinib on OATP and BCRP. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 19
25 Septemeber 2020
Rosuvastatin can be taken with or without food, any time of the day, over a dose range of 5 to 
40 mg once daily. Rosuvastatin peak plasma concentrations are reached in 3 to 5 hours after oral 
dosing, and administration with food does not affect the AUC of ROS. Rosuvastatin is not 
extensively metabolized and the major metabolite, N-desmethyl rosuvastatin, is formed 
principally by CYP2C9; this metabolite displays one-sixth to one-half of the 
HMG-CoA-reductase inhibitory activity of the parent. Overall, greater than 90% of active 
plasma HMG-CoA-reductase inhibitory activity is accounted for by the parent compound. The 
elimination half-life of ROS is approximately 19 hours. Rosuvastatin clearance is not dependent 
on metabolism by CYP3A4 to a clinically significant extent. 
Further information regarding ROS is available in the package insert.
1.2.
Rationale for This Study
The objective of this study is to evaluate filgotinib as a perpetrator of drug-drug interactions
(DDIs) with OATPs. Filgotinib and its metabolite, GS-829845, are determined to be in vitro 
inhibitors of OATP1B1 and OATP1B3. Filgotinib inhibits OATP1B1 and OATP1B3 at a 
half-maximal inhibitory concentration (IC50) of 98 µM and > 285 µM, respectively. GS-829845 
inhibits OATP1B1 and OATP1B3 at an IC50 of 260 µM and > 473 µM, respectively 
(AD-417-2024). Based on in vitro data, filgotinib and GS-829845 are unlikely to have in vivo 
DDIs mediated by OATP1B1 and OATP1B3. Data generated from this study will be used to 
further support the use of filgotinib with OATP substrates such as statins. This study will 
evaluate the potential effect of filgotinib and GS-829845 on OATP1B1 and OATP1B3 
transporters using probe substrates of ATV (probe for CYP3A and OATP), ROS (probe for 
BCRP and OATP), and PRA (probe for OATP). The probe drugs selected for this study are 
based on the recommendations from the International Transporter Consortium on “Membrane 
Transporters in Drug Development” and “Transporters in Drug Development: Advancing on the 
Critical Path”{Giacomini 2010, Huang 2010}.
The design of this study is based on the results of a comprehensive panel of nonclinical studies, 
and in accordance with the Food and Drug Administration (FDA) guidance entitled “Drug 
Interaction Studies Study Design, Data Analysis, Implications for Dosing, and Labeling 
Recommendations” (Jan 2020) and the European Medicines Agency (EMA) guidance entitled 
“Guideline on the Investigation of Drug Interactions” (June 2012).
Data from this DDI study will inform the suitability of filgotinib co-administration with 
concomitant medications and the need for dose adjustment, as applicable.
Healthy participants will be selected for this study to remove any potential confounding effects 
of background medications and other therapies, and to avoid the need to make multiple, 
short-term changes in treatment regimens in patients for the purpose of examining the PK of the 
different agents and their combinations. For safety and adherence monitoring, all participants 
will be confined within a Phase 1 unit for the duration of the study.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 20
25 Septemeber 2020
1.3.
Rationale for the Dose Selection
Filgotinib will be administered at 200 mg once daily for 11 days. The 200 mg once daily dose of 
filgotinib is the highest therapeutic dose under evaluation for multiple inflammatory diseases 
including RA, UC, PsA, and AS. This dose has been selected based on efficacy, tolerability, and 
safety data derived across Phase 1, Phase 2, and Phase 3 clinical studies. In Phase 2 and Phase 3 
studies in participants with RA, treatment with filgotinib was well tolerated and achieved a high 
level of efficacy (ACR20/50/70) at a 200 mg daily dose. Exposure-efficacy analysis based on 
data from all Phase 2 and Phase 3 studies indicated an increase in efficacy (ACR50/70) with 
increasing filgotinib exposure, with a plateau in response corresponding to filgotinib exposures 
at the 200 mg daily dose. No trend in adverse events (AEs) or laboratory abnormalities have
been observed in exposure-safety analysis of filgotinib up to 300 mg administered as once daily 
doses. Therefore, the 200 mg dose of filgotinib is selected as the clinically relevant dose for 
evaluation. Multiple doses of filgotinib at 200 mg once daily is selected to achieve steady state 
exposure of filgotinib and its metabolite, GS-829845, in order to assess the potential impact of 
the highest clinically relevant exposure of filgotinib (as an inhibitor) on the PK of the OATP 
transporter probes (ATV, ROS, and PRA).
Atorvastatin 40 mg (1 40 mg tablet) will be administered as a single dose to healthy 
participants in a crossover design to assess OATP activity in the presence and absence of 
filgotinib. Atorvastatin 40 mg is representative of the middle of the recommended ATV dose 
range used in clinical practice (10 mg to 80 mg). Drug interactions resulting in significant 
changes in ATV exposure generally involve inhibition of CYP3A4 (eg, cyclosporine) 
{Elsby 2012}. Additionally, filgotinib is not expected to be a strong inhibitor of OATPs. 
Accordingly, large increases in ATV exposure are not expected when administered with 
filgotinib, which does not inhibit CYP enzymes.
Pravastatin 40 mg (1 40 mg tablet) will be administered as a single dose to healthy participants 
in a crossover design to assess OATP activity in the presence and absence of filgotinib. 
Pravastatin 40 mg is representative of the middle of the PRA dose range used in clinical practice 
(10 mg to 80 mg). The sensitivity of PRA as an in vivo probe for assessing OATP activity at this 
dose has been previously established {Giacomini 2010}. 
Rosuvastatin 10 mg (1 10 mg tablet) will be administered as a single dose to healthy 
participants in a crossover design to collectively assess OATP1B1/1B3 and BCRP activity in the 
presence and absence of filgotinib {Chu 2018, Giacomini 2010}. Rosuvastatin 10 mg is 
representative of the recommended dose range used in clinical practice (5 mg to 40 mg). 
Collectively, use of both PRA and ROS as probes in this study will allow for a better 
understanding and/or discrimination of the effects of filgotinib and its primary metabolite on 
OATP and BCRP.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 21
25 Septemeber 2020
Rosuvastatin and PRA will be administered as a cocktail of drug transport probe substrates. The 
use of this cocktail as a measure of OATP and BCRP activity has been confirmed in a previous 
study (GS-US-334-2130), in which these probe drugs were administered simultaneously with no 
effect on their respective exposure as compared with administration alone and thus are sensitive 
to measure changes in OATP and BCRP activity when administered as a cocktail.
1.4.
Risk/Benefit Assessment for the Study
Potential risks of a participant’s involvement in this study include AEs related to short-term use 
of filgotinib, ATV, PRA and/or ROS, in addition to the general risks associated with frequent 
laboratory blood draws. 
An infectious disease pandemic may pose additional risks to study drug availability, study visit 
schedule, and adherence to protocol-specified safety monitoring or laboratory assessments. 
There is no anticipated benefit to healthy participants. However, data from this study will support 
the development of filgotinib for the treatment of chronic inflammatory diseases (eg, RA, PsA, 
IBD). All participants will be monitored for AEs and laboratory parameters, and eligibility 
criteria will ensure a healthy participant population. Individual participant and study stopping 
criteria are outlined as an added measure of safety. Finally, safety data will be evaluated on an 
ongoing basis. Taken together with the totality of the nonclinical toxicology and clinical safety 
data outlined in the filgotinib IB, the risks to healthy participants are considered acceptable.
1.5.
Compliance
This study will be conducted in compliance with this protocol, Good Clinical Practice (GCP), 
and all applicable regulatory requirements.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 22
25 Septemeber 2020
2.
OBJECTIVES
The primary objective of this study is as follows:

To evaluate the effect of filgotinib on a mixed OATP/CYP3A, OATP/BCRP, and OATP 
substrates using phenotypic probes
The secondary objective of this study is as follows:

To evaluate the safety and tolerability of multiple filgotinib doses administered alone or in 
combination with probe drugs


Filgotinib 
Protocol GS-US-417-5937 
Gilead Sciences, lnc. 
3. 
STUDY DESIGN 
3.1. 
Study Design 
Final 
Original 
This protocol describes a Phase 1, randomized, two-way crossover, open-label, single and 
multiple dose, single center study to evaluate the effect of filgotinib on a mixed OATP/CYP3A, 
OATP/BCRP, and OATP substrates using phenotypic probes in healthy nonnal participants. Up 
to 30 participants will be enrolled. 
Healthy surgically sterile male and nonpregnant, nonlactating female participants aged 18 
through 55 years will be enrolled into the study. 
An overview of the study design is described below and shown in Figure 3-1 and Figure 3-2. 
Treatment A: Single dose of ATV 40 mg, followed by a washout period of 1 day and a single 
dose of the PRA 40 mg/ROS 10 mg cocktail 
Treatment B: Filgotinib 200 mg administered once daily for 11 days, with a single dose of A TV 
40 mg administered on the sixth day or a single dose of PRA 40 mg/ROS 10 mg cocktail 
administered on the eighth day 
Figure 3-1. 
28 
Study Schema - Sequence AB 
1 
17 
24 (±2) 
1 
3 
7 
11 12 13 14 15 16 
Screening 
Admission 6. 
• 
Clinic Confinement 
Intensive PK sampling 
• 
Filgotinib 
6. 
Atorvastatin 
• 
Pravastatin + Rosuvastatin 
I 
Washout 
CONFIDENTIAL 
____ _..., ••• 
6. 
• 
Page 23 
e Discharge 
Follow up 
25 Septemeber 2020 


Filgotinib 
Protocol GS-US-417-5937 
Final 
Gilead Sciences, lnc. 
Original 
Figure 3-2. 
Study Schema - Sequence BA 
3.2. 
-28 
Screening 
-• 
6. • 
I 
-1 
1 
5 6 7 8 
Clinic Confinement 
Intensive PK sampling 
Filgotinib 
Atorvastatin 
Pravastatin + Rosuvastatin 
Washout 
Study Drug Administration 
11 
23 
27 (±2) 
18 
20 
Follow up 
Please refer to Section 5.3 for additional infonnation for study drug dosage and administration. 
3.3. 
Duration of Dosing 
Participants will dose for 13 days, all of which occur during the clinic confinement. 
3.4. 
Clinic Confinement 
Following screening and admission procedures, eligible participants will be confined to the study 
center beginning at admission on Day 1 until the completion of assessments on Day 17 
(Sequence AB) or Day 23 (Sequence BA). All participants will be contacted by telephone 
7 (± 2) days after last dose for follow up (ie, on Day 24 [± 2] for Sequence AB or on Day 27 
[ ± 2] for Sequence BA). 
3.5. 
Pharmacokinetic Assessments 
Phannacokinetic assessments will occur on assigned study days as outlined in Table 6-1 through 
Table 6-2 and in Section 6.5. 
CONFIDENTIAL 
Page 24 
25 Septemeber 2020 


Filgotinib 
Protocol GS-US-417-5937 
Gilead Sciences, lnc. 
3.5.1. 
Plasma Pharmacokinetic Collection 
Final 
Original 
Plasma concentrations of ATV, PRA, and ROS will be detennined and PK parameters estimated 
as outlined in Section 6.5.1. Plasma concentrations of filgotinib and its metabolite (GS-829845) 
may be analyzed. Plasma concentrations of metabolites of probe drugs or filgotinib may be 
analyzed, if applicable. 
3.5.2. 
Genomic Sample Collection 
A mandatory blood sample will be collected from all participants who have provided consent to 
participate in this study. This sample will be collected for the extraction of DNA for genomic 
testing and genotyping to identify polymorphisms of drug transporters ( eg, OA TP 1 B 1) . This 
sample should be collected on Day 1, before administration of the first dose of study drug, but 
may be collected at any time during the study, if neccessary. 
3.6. 
Safety Assessments 
Safety assessments will be perfonned through the study as outlined in Table 6-1 through 
Table 6-2 and in Section 6.6. 
3.7. 
End of Study 
The end of this study will be the last participant's last observation ( or visit). 
3.8. 
Discontinuation Criteria 
Study treatment and/or study procedures may be discontinued in the following instances: 
• 
Intercurrent illness that would, in the judgment of the investigator, affect assessments of 
clinical status to a significant degree 
• 
Unacceptable toxicity, as defined in the toxicity management section of the protocol, or 
toxicity that, in the judgment of the investigator, compromises the ability to continue 
study-specific procedures or is considered not to be in the participant's best interest 
• 
Participant requests to discontinue for any reason 
• 
Participant noncompliance 
• 
Pregnancy during the study (refer to Appendix 2) 
• 
Investigator discretion 
• 
Discontinuation of the study at the request of Gilead, regulatory agency, or an institutional 
review board (IRB) 
CONFIDENTIAL 
Page 25 
25 Septemeber 2020 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 26
25 Septemeber 2020
3.9.
Source Data
The source data for this study will be obtained from electronic data capture (EDC), a local 
laboratory, and specialty laboratory (for PK and/or pharmacodynamics data) .
3.9.1.
Discontinuation
3.9.1.1.
Study Stopping Criteria

If 3 or more participants in any group experience the same or similar Grade 3 
treatment-emergent AE or confirmed laboratory abnormality, unless there is a clear and 
obvious physiologic explanation for the events (eg, blood in urine occurring in a 
menstruating female or creatine phosphokinase (CPK) elevation after strenuous exercise, 
etc.), then a review of all safety data generated in participants dosed to date will be initiated.

If 2 or more participants in any group experience the same or similar Grade 4 
treatment-emergent AE or confirmed laboratory abnormality, then a review of all safety data 
generated in participants dosed to date will be initiated. Dosing will be on hold until the 
review of all the safety data is completed. If the safety review determines that it is safe and 
tolerable to continue dosing, study drug administration will continue. If the safety review 
determines that dosing should not continue, the study will be stopped. The decision whether 
or not to complete the full course of study medication will be made by the sponsor, in 
consultation with the principal investigator, with disclosure of new information to the study 
participant(s).


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 27
25 Septemeber 2020
4.
PARTICIPANT POPULATION
4.1.
Number of Participants and Participant Selection
Approximately 30 unique participants will be enrolled in the study, which include healthy 
nonpregnant, nonlactating female and surgically sterile male participants 18 through 55 years of 
age, inclusive
4.1.1.
Participant Replacement
If necessary, replacement participants may be enrolled after discussion and approval from the 
sponsor if participants do not complete all intensive PK procedures or the participant is 
considered nonevaluable. Replacement participants will not be enrolled for participants who 
discontinue the study due to study drug-related AEs.
4.2.
Inclusion Criteria
Participants must meet all of the following inclusion criteria to be eligible for participation in this 
study:
1) Have the ability to understand and sign a written informed consent form (ICF), which must 
be obtained prior to initiation of study procedures
2) Be aged 18 through 55 years, inclusive, at screening
3) Be a nonsmoker. The use of nicotine or nicotine-containing products must be discontinued 
90 days prior to the first dose of study drug
4) Have a calculated body mass index (BMI) of ≥19.0 and ≤30.0 kg/m2 at screening
5) Have a creatinine clearance (CLcr) ≥90 mL/min (using the Cockcroft-Gault method 
{Cockcroft 1976}) based on serum creatinine and actual body weight as measured at 
screening and upon admission:
Male:
(140
Age [years]) (Weight [kg])
CLcr (mL/min)
72 (Serum Creatinine [mg/dL])
Female:
(140
Age [years]) (Weight [kg]) 0.85 
CLcr (mL/min)
72 (Serum Creatinine [mg/dL])
6) Female participants of childbearing potential (as defined in Appendix 2) must have a 
negative serum pregnancy test at screening and a negative urine pregnancy test at clinic 
admission.
7) Male participants must be surgically sterile


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 28
25 Septemeber 2020
8) Male participants and female participants of childbearing potential who engage in 
heterosexual intercourse must agree to use protocol-specified method(s) of contraception as 
described in Appendix 2.
9) Screening laboratory evaluations and 12-lead electrocardiogram (ECG) evaluations must be 
without clinically significant abnormalities as assessed by the investigator.
10) Have liver biometric tests such as alanine aminotransferase (ALT), aspartate 
aminotransferase (AST), alkaline phosphatase, and total bilirubin below the upper limit of 
normal at screening
11) Must be willing and able to comply with all study requirements
12) Must, in the opinion of the investigator, be in good health based upon medical history and 
physical examination, including vital signs
13) Participants must not have donated blood within 56 days of study entry or plasma within 
7 days of study entry and must refrain from blood donation from clinic admission, 
throughout the study period, and continuing for at least 30 days following the last dose of 
study drug.
4.3.
Exclusion Criteria
Participants who meet any of the following exclusion criteria will not be enrolled in this study:
1) Positive serum pregnancy test (Female participant) (Appendix 2)
2) Lactating female
3) Have received any investigational drug/device within 30 days prior to study dosing (or within 
5 half-lives of the drug, whichever is longer)
4) Have current alcohol or substance abuse judged by the investigator to potentially interfere 
with participant compliance or participant safety, or a positive drug or alcohol test at 
screening or admission.
5) Have a positive test result for human immunodeficiency virus type 1 (HIV-1) antibody, 
hepatitis B virus (HBV) surface antigen (HBsAg), or hepatitis C virus (HCV) antibody at 
screening
6) Have positive Coronavirus Disease 2019 (COVID-19) Real-Time Reverse 
Transcriptase-Polymerase Chain Reaction (RT-PCR) testing on screening and admission.
7) Have poor venous access that limits phlebotomy


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 29
25 Septemeber 2020
8) Have taken any prescription medications or over-the-counter medications, including herbal 
products, within 28 days prior to start of study drug dosing, with the exception of vitamins 
and/or acetaminophen and/or ibuprofen and/or hormonal contraceptive medications
9) Have been treated with systemic steroids, immunosuppressant therapies, or chemotherapeutic 
agents within 3 months prior to screening or is expected to receive these agents during the 
study (eg, corticosteroids, immunoglobulins, other immune- or cytokine-based therapies)
10) Have a history of any of the following:
a.
Significant serious skin disease, such as but not limited to rash, food allergy, eczema, 
psoriasis, or urticaria
b. Significant drug sensitivity or drug allergy (such as anaphylaxis or hepatoxicity)
c.
Known hypersensitivity to the study drugs, their metabolites, or to formulation excipients 
(see Section 5)
d. Significant cardiac disease (including history of myocardial infarction based on ECG 
and/or clinical history, any history of ventricular tachycardia, congestive heart failure, or 
dilated cardiomyopathy with left ventricular ejection fraction < 40%), a family history of 
long QT syndrome, or unexplained death in an otherwise healthy individual between the 
ages of 1 and 30 years
e.
Recurrent syncope, palpitations, or unexplained dizziness
f.
Implanted defibrillator or pacemaker
g. Liver disease, including Gilbert syndrome
h. Severe peptic ulcer disease, gastroesophageal reflux disease, or other gastric acid 
hypersecretory conditions requiring prolonged (> 6 months) medical treatment
i.
Medical or surgical treatment that permanently altered gastric absorption (eg, gastric or 
intestinal surgery). A history of cholecystectomy is not exclusionary 
11) Have any serious or active medical or psychiatric illness (including depression) that, in the 
opinion of the investigator, would interfere with participant treatment, assessment, or 
compliance with the protocol. This would include renal, cardiac, hematological, hepatic, 
pulmonary (including chronic asthma), endocrine (including diabetes), central nervous, 
gastrointestinal (including an ulcer), vascular, metabolic (thyroid disorders, adrenal disease), 
immunodeficiency disorders, active infection, or malignancy that are clinically significant or 
requiring treatment.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 30
25 Septemeber 2020
5.
STUDY DRUGS
5.1.
Randomization, Blinding, and Treatment Codes Access
5.1.1.
Randomization
Following screening and admission assessments, eligible participants will be confined to the 
study center. Once eligibility has been confirmed and following completion of the admission 
study procedures, eligible participants will be randomized at 1:1 ratio on the evening of Day 1 
to receive 1 of 2 treatment sequences starting on Day 1.
All screening and admission (Day 1) tests and procedures must be completed and reviewed by 
the investigator prior to the administration of the first dose of study drug on Day 1. It is the 
responsibility of the investigator to ensure that the participant is eligible for the study prior to 
enrollment. Once a participant number has been assigned to a participant, it will not be 
reassigned to another participant. If necessary, replacement participants may be enrolled after 
discussion and approval from the sponsor. 
5.1.2.
Blinding
Blinding of treatment assignments or data will not be performed in this study.
5.2.
Description and Handling of Filgotinib
5.2.1.
Formulation
Filgotinib is provided as 200 mg strength tablets. Filgotinib tablets, 200 mg, are beige, debossed 
with “GSI” on one side and “200” on the other, capsule-shaped, film-coated tablets. Each tablet 
contains the equivalent of 200 mg filgotinib free base in the form of filgotinib maleate. In 
addition to the active ingredient, filgotinib tablets contain the following inactive ingredients: 
microcrystalline cellulose, lactose monohydrate, fumaric acid, pregelatinized starch, silicon 
dioxide, magnesium stearate, macrogol/PEG 3350, polyvinyl alcohol, talc, titanium dioxide, iron 
oxide yellow, and iron oxide red.
5.2.2.
Packaging and Labeling
Filgotinib tablets, 200 mg, are packaged in white, high density polyethylene (HDPE) bottles. 
Each bottle contains 30 tablets, silica gel desiccant and polyester packing material. Each bottle is 
enclosed with a white, continuous thread, child-resistant polypropylene screw cap fitted with an 
induction-sealed and aluminum-faced liner.
Sufficient quantities of filgotinib tablets, 200 mg to complete the entire study will be shipped to 
the investigator or qualified designee from the Gilead Supply Management Team.
Study drugs to be distributed to the participating site shall be labeled to meet applicable 
requirements of the United States FDA.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 31
25 Septemeber 2020
5.2.3.
Storage and Handling
Filgotinib tablets should be stored at controlled room temperature of 25 °C (77 °F); excursions 
are permitted between 15 °C and 30 °C (59 °F to 86 °F).
Storage conditions are specified on the label. Until dispensed to the participants, all drug 
products should be stored in a securely locked area, accessible only to authorized site personnel. 
To ensure the stability of the study drug and to ensure proper product identification, the drug 
product should not be stored in a container other than the container in which they are supplied. 
Consideration should be given to handling, preparation, and disposal through measures that 
minimize drug contact with the body. Appropriate precautions should be followed to avoid direct 
eye contact or exposure when handling.
5.3.
Description and Handling of Commercially Available Drugs
Commercial product of ATV, PRA, and ROS will be used for the study. Further information 
regarding storage and handling are available in the Prescribing Information for these commercial 
products.
5.4.
Dosage and Administration of Study Drug
Following completion of screening and admission assessments (Day 1), eligible participants 
will be randomized the evening of Day 1 to receive 1 of 2 treatment sequences starting on 
Day 1:
OATP/CYP3A substrate: ATV 40 mg
OATP substrate: PRA 40 mg
OATP/BCRP substrate: ROS 10 mg
Pravastatin/Rosuvastatin (PRA/ROS) will be coadministered as a probe cocktail.
Treatment A: Single dose of ATV 40 mg, followed by a washout period of one day followed by
a single dose of the PRA 40 mg/ROS 10 mg cocktail 
Treatment B: Filgotinib 200 mg administered once daily for 11 days, with a single dose of ATV 
40 mg administered on the sixth day followed by a single dose of PRA 40 mg/ROS 10 mg
cocktail administered on the eighth day


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 32
25 Septemeber 2020
Sequence
Days
AB
Period 1
Period 2
1
2
3
4-6
7-
11
12
13
14
15-17
ATV
WO
PRA + ROS
WO
FIL
FIL
+
ATV
FIL
FIL + PRA + 
ROS
FIL
BA
Period 1
Period 2
1-5
6
7
8
9-
11
12-
17
18
19
20
FIL
FIL + 
ATV
FIL
FIL + PRA + ROS
FIL
WO
ATV
WO
PRA + 
ROS
FIL  filgotinib; ATV  atorvastatin; PRA  pravastatin; ROS  rosuvastatin; WO Washout
5.5.
Fasting and Meals
All study treatments will be administered orally at the study center in the morning at 
approximately the same time on each day with 240 mL of water following an overnight fast 
(no food or drink, except water, for at least 10 hours). On non-intensive PK days, participants 
will continue to fast for 2 hours postdose relative to study drug dosing.
On the days of intensive PK sampling(Days 1, 3, 12, and 14 for Sequence AB and Days 6, 8, 18, 
and 20 for Sequence BA), the study drug will be administered in the morning following an 
overnight fast (no food or drink, except water, for at least 10 hours). On intensive PK days, 
participants will be restricted from food intake until after collection of the 4-hour blood draw. 
Participants will continue to fast until after collection of the 4-hour PK sample, relative to study 
drug dosing. Additionally, participants will be restricted from water consumption 1 hour before 
and until 2 hours after dosing, except for the 240 mL given with the study treatment(s). After 
collection of the 4-hour PK sample, participants will be provided with a standardized meal.
All meals and/or snacks given to participants during their stay in the clinical study facility will be 
standardized for all participants and should be similar in calorie and fat content and taken at 
approximately the same time each day. All meals provided must be approved by the sponsor. 
Components of meals (eg, margarine, jelly, bread) should be given to participants in individual 
portions (eg, 1 tablespoon) per the approved meal schedule. The provision of meal components 
in bulk (eg, a jar of jelly for participants to share) should not be practiced. All meals should be 
given at approximately the same time each day (eg, 07:30, 12:00, 18:00).
5.6.
Dispensing, Accountability, and Disposal or Return of Study Drug
The investigator (or designee, eg, study center pharmacist) will acknowledge receipt of the study 
drug (after reviewing the shipment’s content and condition) from Gilead (or designee). The 
investigator will maintain an accurate inventory of all study drug(s). Each dose of the study 
drug(s) administered at the study center will be administered by qualified study center staff. The 
dose of study drug(s) administered to participants in the clinic under the supervision of staff will 
be accurately recorded on the Study Drug Accountability form provided by Gilead (or on 
equivalent documentation maintained by the study center), which indicates the date and quantity 
of each dosage formulation dispensed to individual participants.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 33
25 Septemeber 2020
Gilead recommends that used and unused study drug should be destroyed at the site. If the site 
has an appropriate Standard Operating Procedure (SOP) for drug destruction as determined by 
Gilead, the site may destroy used (empty or partially empty) and unused study drug supplies in 
accordance with that site’s approved SOP. A copy of the site’s approved SOP will be obtained 
for the eTMF. If study drug is destroyed onsite, the investigator must maintain accurate records 
for all study drugs destroyed. Records must show the identification and quantity of each unit 
destroyed, the method of destruction, and the person who disposed of the study drug. Upon study 
completion, copies of the study drug accountability records must be filed at the site. Another 
copy will be returned to Gilead. 
If the site does not have an appropriate SOP for drug destruction, used and unused study drug
supplies are to be sent to the designated disposal facility for destruction. The study monitor will 
provide instructions for return.
The study monitor will review study drug supplies and associated records at periodic intervals.
For both disposal options listed above, the study monitor must first perform drug accountability 
during a monitoring visit.
5.7.
Concomitant Medications and Other Protocol Restrictions
5.7.1.
Concomitant Medications 
The following medications are excluded while participants are participating in the study (from 
screening until discharge):

Any prescription medications and over-the-counter medications, including herbal products 
and antacids, with the exception of vitamins, and/or acetaminophen and/or ibuprofen and/or 
hormonal contraceptive medications. However, the short-term use of topical hydrocortisone 
cream or AD ointment to treat minor skin irritation due to ECG leads will be allowed. If a 
participant requires use of a disallowed medication, a request for such use must be reviewed 
by the sponsor and if approved, participants may continue to participate in the study.

Any and all illegal or illicit drug use, including use of prescription drugs outside the care of 
the prescribing physician.
5.7.2.
Other Protocol Restrictions

Participants will be required to refrain from the consumption of food and beverages 
containing alcohol 72 hours prior to the first dose of study drug and during the course of the 
study through discharge.

Participants will be required to refrain from the use of nicotine or nicotine-containing 
products 90 days prior to first dose of study drug and during the course of the study through 
discharge. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 34
25 Septemeber 2020

Participants will be required to refrain from consumption of grapefruit juice, grapefruits, and 
Seville orange juice 72 hours prior to the first dose of study drug and during the course of the 
study through discharge.

While confined at the study center, tea, coffee, chocolate, and other foods and beverages 
containing caffeine and other methyl xanthines will be prohibited on each dosing day. At all 
other times, caffeine-containing beverages and foodstuffs may be served or withheld in 
accordance with normal study center practice. Caffeine-containing beverages and foodstuffs 
will not be restricted while participants are outside of the clinic.

Participants will be encouraged to avoid strenuous or prolonged exercise, as well as saunas, 
steambaths, and sunbathing or other prolonged ultraviolet exposure (eg, in a tanning salon)
from the screening evaluation and during the course of the study through discharge, as these 
activities are known to affect certain clinical laboratory test parameters (eg, creatine kinase) 
and will provide false indicators of a potentially treatment-related toxicity. 
Upon every admission to the clinic, each participant will be questioned as to their compliance 
with the above protocol restrictions. If a participant is unable to comply with any of the 
restrictions described above, the participant’s continued participation in the study will be 
reevaluated by the investigator in consultation with the sponsor.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 35
25 Septemeber 2020
6.
STUDY ASSESSMENTS
The study procedures to be conducted for each participant enrolled in the study are detailed 
below.
Any deviation from protocol procedures should be noted in the participant’s clinical chart and 
appropriate electronic case report forms (eCRFs). In addition, the sponsor should be promptly 
notified of any protocol deviations. 
The study center will not initiate dosing until the following have all been met:

The IRB has reviewed and approved the study and the informed consent document.

All requested regulatory documents have been submitted to and approved by Gilead.

A master services agreement and/or study agreement is executed.

The study initiation meeting has been conducted by the Gilead (or designee).
The initiation meeting will include but is not limited to a review of the protocol, the IB, study 
drugs, and investigator responsibilities.
Documentation of the personally signed and dated ICF for each participant, using the 
study-specific, IRB approved ICF, is required before initiating the screening process. 
6.1.
Participant Enrollment and Treatment Assignment
Entry into screening does not guarantee enrollment into the study. In order to manage the total 
study enrollment, Gilead, at its sole discretion, may suspend screening and/or enrollment only a 
single site at any time.
It is the responsibility of the investigator to ensure that participants are eligible to participate in 
the study prior to enrollment and continue to remain eligible throughout the study.
Once the ICF has been obtained, all screening and admission tests and assessments have been 
assessed, and study eligibility has been confirmed, participants will be enrolled to receive study 
drug on Day 1.
Participants will receive the study treatments as described in Section 5.3.


Filgotinb
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc. 
Original
CONFIDENTIAL
Page 36
24 Septemeber 2020
Table 6-1.
Schedule of Assessments (Sequence AB)
Study 
Procedure
Screening
a
Admission
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
Day 13
Day 14
Day 15
Day 16
Discharge
Day 17b
Follow-Upc
Day 24± 2
ETd
Written 
Informed 
Consent
X
Medical 
History 
X
Complete 
Physical 
Examination
X
X
X
X
X
Symptom
Driven Physical 
Examinatione
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Height 
X
Weight 
X
X
X
X
X
X
Vital Signsf
X
X
X
X
X
X
X
X
X
X
X
X
HIV 1, HBV, 
and HCV 
Testingg
X
Hematologyg
X
X
X
X
X
X
X
X
X
X
X
X
Chemistryg
X
X
X
X
X
X
X
X
X
X
X
X
Creatine 
phosphokinase 
(CPK)
X
X
X
X
X
X
X
X
X
X
X
X
Calculated 
Creatinine 
Clearance
X
X
X
X
X
X
Urinalysisg
X
X
X
X
X
X
X
X
X
X
X
X
Serum 
Pregnancy 
Testg,h
X
X
X
X
Urine 
Pregnancy Test
h
X
X


Filgotinb
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc. 
Original
CONFIDENTIAL
Page 37
24 Septemeber 2020
Study 
Procedure
Screening
a
Admission
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
Day 13
Day 14
Day 15
Day 16
Discharge
Day 17b
Follow-Upc
Day 24± 2
ETd
Follicle
Stimulating 
Hormone 
(FSH)g,h
X
Thyroid 
Stimulating 
Hormone 
(TSH)gh
X
Urine Drug and 
Alcohol 
Screeng
X
X
12 Lead ECG
X
COVID 19
RT PCR
X
X
Randomization/
Enrollmenti
X
Study Drug 
Administrationj
X
X
X
X
X
X
X
X
X
X
X
X
X
Intensive 
Plasma PKk
X
X
X
X
Genotype 
Testingl
X
Review Study 
Restrictions
X
X
X
X
Clinic 
Confinement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Review AEs & 
Concomitant 
Medicationsm
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
AE  adverse event; ECG  electrocardiogram; COVID 19 RT PCR
a real time reverse transcription polymerase chain reaction (rTT PCR) test for the qualitative detection of 
nucleic acid from SARS CoV 2
eCRF
electronic case report form; ET  early termination; HBV  hepatitis B virus; HCV  hepatitis C virus; HIV 1  human immunodeficiency virus type 1 and type 2; 
PE
physical examination; PG  pharmacogenomic; PK  pharmacokinetic(s
a.
Prospective participant should be screened no more than 28 days prior to administration of the first dose of study drug.


Filgotinb
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc. 
Original
CONFIDENTIAL
Page 38
24 Septemeber 2020
b.
Participants will be discharged from the clinic on Day 17 (Sequence AB) following all assessments.
c.
7 (± 2) days after the last administration of study drug, all participants will be contacted via telephone to review and document AEs and concomitant medications 
d.
Early termination (ET) assessments will be performed within 72 hours of prematurely discontinuing from the study.
e.
Symptom driven PEs will be performed during confinement as needed, based on reported signs and symptoms.
f.
Vital signs include blood pressure, heart rate, respiration rate, and body temperature.
g.
See Section 6.6.5 for specifics.
h.
Females of childbearing potential only.
i.
On Day 1, participants will be randomized the evening to receive 1 of 2 treatment sequences starting on Day 1. 
j.
See Section 5.4 for specifics.
k.
Intensive PK sampling will occur relative to the morning dosing of study drug at the time points as outlined in Section 6.5.1.
l.
Blood sample should be collected on Day 1, but may be collected at any time during the study, if necessary
m.
From the time of obtaining informed consent through the first administration of study drug, record all SAEs, as well as any nonserious AEs related to protocol mandated 
procedures, on the AE eCRF. All other untoward medical occurrences observed during the screening period, including exacerbation or changes in medical history, are to be 
captured on the medical history eCRF. See Section 7, Adverse Events and Toxicity Management, for additional details.
Table 6-2.
Schedule of Assessments (Sequence BA)
Study 
Procedure
Screening
a
Admission
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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge
Day 23b
Follow-Upc
Day 27 ± 2
ETd
Written 
Informed 
Consent
X
Medical 
History 
X
Complete 
Physical 
Examination
X
X
X
X
X
Symptom
Driven 
Physical 
Examinatione
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Height 
X
Weight 
X
X
X
X
X
X
X
Vital Signsf
X
X
X
X
X
X
X
X
X
X
X
X
X
HIV 1, HBV, 
and HCV 
Testingg
X
Hematologyg
X
X
X
X
X
X
X
X
X
X
X
X
X


Filgotinb
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc. 
Original
CONFIDENTIAL
Page 39
24 Septemeber 2020
Study 
Procedure
Screening
a
Admission
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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge
Day 23b
Follow-Upc
Day 27 ± 2
ETd
Chemistryg
X
X
X
X
X
X
X
X
X
X
X
X
X
Creatine 
phosphokinase 
(CPK)
X
X
X
X
X
X
X
X
X
X
X
X
X
Calculated 
Creatinine 
Clearance
X
X
X
X
X
X
X
Urinalysisg
X
X
X
X
X
X
X
X
X
X
X
X
X
Urine 
Pregnancy Test
X
X
Follicle
Stimulating 
Hormone 
(FSH) g,h
X
Thyroid 
Stimulating 
Hormone 
(TSH)gh
X
Serum 
Pregnancy 
Testg, h
X
X
X
X
X
Urine Drug and 
Alcohol 
Screeng
X
X
12 Lead ECG
X
COVID 19 
RT PCR
X
X
Randomization
/Enrollmenti
X
Study Drug 
Administrationj
X
X
X
X
X
X
X
X
X
X
X
X
X
Intensive 
Plasma PKk
X
X
X
X
Genotype 
Testingl
X


Filgotinb
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc. 
Original
CONFIDENTIAL
Page 40
24 Septemeber 2020
Study 
Procedure
Screening
a
Admission
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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge
Day 23b
Follow-Upc
Day 27 ± 2
ETd
Review Study 
Restrictions
X
X
X
X
Clinic 
Confinement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Review AEs & 
Concomitant 
Medicationsm
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
AE  adverse event; ECG  electrocardiogram; COVID 19 RT PCR a real time reverse transcription polymerase chain reaction (rTT PCR) test for the qualitative detection of 
nucleic acid from SARS CoV 2
eCRF  electronic case report form; ET  early termination; HBV  hepatitis B virus; HCV  hepatitis C virus; HIV 1  human immunodeficiency virus type 1 and type 2; PE 
physical examination; PG  pharmacogenomic; PK  pharmacokinetic(s); COVID 19 RT PCR a real time reverse transcription polymerase chain reaction (rTT PCR) test for the 
qualitative detection of nucleic acid from SARS CoV 2
a.
Prospective participants should be screened no more than 28 days prior to administration of the first dose of study drug.
b.
Participants will be discharged from the clinic on Day 23 (Sequence BA) following all assessments.
c.
7 (± 2) days after the last administration of study drug, all participants will be contacted via telephone to review and document AEs and concomitant medications.
d.
Early termination (ET) assessments will be performed within 72 hours of prematurely discontinuing from the study.
e.
Symptom driven PEs will be performed during confinement as needed, based on reported signs and symptoms.
f.
Vital signs include blood pressure, heart rate, respiration rate, and body temperature.
g.
See Section 6.6.5 for specifics.
h.
Females of childbearing potential only.
i.
On Day 1, participants will be randomized the evening to receive 1 of 2 treatment sequences starting on Day 1.
j.
See Section 5.4 for specifics.
k.
Intensive PK sampling will occur relative to the morning dosing of study drug at the time points as outlined in Section 6.5.1.
l.
Blood samples should be collected on Day 1, but may be collected at any time during the study, if necessary
m.
From the time of obtaining informed consent through the first administration of study drug, record all SAEs, as well as any nonserious AEs related to protocol mandated 
procedures, on the AE eCRF. All other untoward medical occurrences observed during the screening period, including exacerbation or changes in medical history, are to be 
captured on the medical history eCRF. See Section 7, Adverse Events and Toxicity Management, for additional details.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 41
25 Septemeber 2020
6.2.
Pretreatment Assessments
6.2.1.
Screening Assessments
Prospective participants should be screened no more than 28 days prior to administration of the 
first dose of study drug. If a participant does not begin the treatment phase within this 28-day 
window, all screening evaluation procedures must be repeated. Screening laboratory assessments 
may be repeated once within 28 days prior to administration of study drug to rule out laboratory 
error.
A sufficient number of participants will be screened to identify planned number of participants 
for randomization.
Participants should be instructed to fast (no food or drink, except water), starting from midnight 
(00:00) or earlier, as appropriate, on the evening prior to the screening visit to ensure an 
approximate 8-hour fast prior to the fasted blood sample collection the next morning.
Written informed consent must be obtained from each participant before initiation of any
screening procedure. After a participant has provided informed consent, the investigator and 
other study personnel will determine if the participant is eligible for participation in the study. 
This assessment will include a review of the inclusion/exclusion criteria and completion of all 
screening procedures as outlined in Table 6-1 through Table 6-2 and described in the following 
text. 
Eligible participants meeting all of the inclusion criteria and none of the exclusion criteria will be 
instructed on all protocol requirements, including the restrictions on concomitant medication 
usage and other substances as well as consumption of food or beverages containing alcohol, 
caffeine, or xanthine. Participants will be asked to arrive at the study center on Day 1 for 
admission assessments.
From the time of obtaining informed consent through the first administration of study drug, 
record all serious adverse events (SAEs), as well as any adverse events related to 
protocol-mandated procedures on the adverse events case report form (AE eCRF). All other 
untoward medical occurrences observed during the screening period, including exacerbation or 
changes in medical history are to be captured on the medical history eCRF. See Section 7,
Adverse Events and Toxicity Management, for additional details.
6.2.2.
Admission Assessments
6.2.2.1.
Admission
Participants should be instructed to fast (no food or drink, except water), starting from midnight 
(00:00) or earlier, as appropriate, on the evening prior to the admission visit to ensure an 
approximate 8-hour fast prior to the fasted blood sample collection.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 42
25 Septemeber 2020
Participants meeting all eligibility criteria following the screening evaluation will return to the 
clinic for admission assessments on Day
1. The admission evaluations and/or procedures are 
outlined in Table 6-1 through Table 6-2.
Prior to dosing on Day 1, the results of the clinical and laboratory evaluations (as described in 
Table 6-1 through Table 6-2) must be reviewed by the investigator to confirm the continued 
eligibility of each participant to participate in the study. At the time of randomization, 
participants will be assigned a participant number as described in Section 5.1. Participants will 
remain confined to the study clinic for the duration as described in Section 6.2.2.2 and Table 6-1
through Table 6-2.
Prior to study drug administration, record any SAEs and all AEs related to protocol-mandated 
procedures. After drug administration, report all AEs and SAEs.
6.2.2.2.
Clinic Confinement
Participants will be confined to the study clinic starting at on Day 1 until completion of 
assessments on Day 17 (Sequence AB) or Day 23 (Sequence BA).
6.3.
Check-in Assessments
Following completion of screening and Day 1 assessments, eligible participants will be 
randomized the evening of Day 1 to receive 1 of 2 treatment sequences starting on Day 1 in 
Section 5.4.
6.4.
Treatment Assessments
Study treatment assessments are outlined in Table 6-1 through Table 6-2.
6.5.
Pharmacokinetic Assessments
6.5.1.
Plasma PK Collection
Plasma concentrations of ATV, PRA, and ROS will be determined and PK parameters evaluated. 
Plasma concentrations of filgotinib and its metabolite (GS-829845) may be analyzed. Plasma 
concentrations of metabolites of probe drugs or filgotinib may be analyzed, if applicable.
Intensive PK sampling will occur relative to dosing of study drug at the following time points:
Sequence AB:

Days 1 and 12: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 24, 36, and 
48 hours postdose

Days 3 and 14: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 48, and 72 hours 
postdose


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 43
25 Septemeber 2020
Sequence BA: 

Days 6 and 18: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 24, 36, and 
48 hours postdose

Days 8 and 20: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 48, and 72 hours 
postdose
6.6.
Safety Assessments
Safety will be evaluated throughout the study. Refer to Table 6-1 through Table 6-2 for the 
schedule of assessments.
6.6.1.
Electrocardiogram Assessment
Participants should rest quietly in the supine position for a minimum of 10 minutes prior to each 
scheduled ECG acquisition and should remain in that position until the recording is complete.
There should be no environmental distractions (including TV, radio, video games, and 
conversation) while the participants are resting prior to and during the recordings. 
Electrocardiograms will be recorded using the site’s standard ECG equipment. All ECGs will be 
obtained using instruments that analyze data using the same algorithms and produce the same 
data for interpretation. Electrode placement will be performed according to the method of 
Wilson, Goldberger, and Einthoven with a check to confirm that the aVR lead is not inverted.
The investigator or other qualified individuals at the study center will review ECGs to assess for 
changes in ECG intervals and morphology as compared with pretreatment ECGs. The ECG 
interval measurements output by the machine will be used for bedside safety monitoring.
Collection of additional ECGs for routine safety monitoring at additional time points or days is at 
the discretion of the investigator based on GCP.
6.6.2.
Physical Examination
Physical examinations conducted throughout the study will be a complete physical examination 
or a symptom-driven physical examination, as outlined in Table 6-1 through Table 6-2. The 
complete physical examination conducted at screening will also include the following 
assessments:

Review medical history, including history of allergies, prior and current use of nicotine or 
nicotine-containing products, alcohol and illegal drug use, and prior (within 30 days) and 
current medication use


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 44
25 Septemeber 2020
6.6.3.
Vital Signs
Vital sign measurements include blood pressure, heart rate, respiratory rate, and body 
temperature and should be taken in the supine position. Participant position for measurement 
should be kept consistent throughout the study. Refer to Table 6-1 through Table 6-2 for vital 
signs collection time points.
6.6.4.
Body Mass Index
Height and weight will be collected at screening for calculation of BMI for inclusion criteria.
6.6.5.
Clinical Laboratory Tests/Assessments
Blood and urine samples for safety evaluations will be collected throughout the study as outlined 
in Table 6-1 through Table 6-2.
6.6.5.1.
Blood Sampling
Blood samples will be collected for the following laboratory analyses:

Hematology: Hematocrit, hemoglobin, platelet count, red blood cell count, white blood cell
count with differential (absolute and percentage), including lymphocytes, monocytes, 
neutrophils, eosinophils, basophils, and mean corpuscular volume 

Chemistry (fasting): alkaline phosphatase, AST, ALT, total bilirubin, direct and indirect 
bilirubin, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, 
total protein, albumin, lactic acid dehydrogenase, CPK, bicarbonate, blood urea nitrogen, 
calcium, chloride, creatinine (see below), glucose, phosphorus, magnesium, potassium, 
sodium, uric acid, and amylase (reflex lipase testing is performed in participants with total 
amylase > 1.5 × upper limit of normal )

Serum pregnancy test (females of childbearing potential only)

Follicle-stimulating hormone testing (screening only): females who have ceased 
menstruating for ≥12 months but do not have documentation of ovarian hormonal failure
only

Thyroid stimulating hormone testing (screening only)

HIV-1, HBV, and HCV testing (screening only)

COVID-19 RT-PCR testing will be conducted and reviewed per site specific policy at 
screening, admission, and as needed during the study. Alternatively, a comparable test may 
be used after consultation with the Sponsor. 


Filgotinib 
Protocol GS-US-417-5937 
Gilead Sciences, lnc. 
6.6.5.2. 
Urine Samples 
Final 
Original 
Urine samples will be collected for urinalysis, urine pregnancy (females only) and alcohol and 
drug screen assessments. 
6.6.6. 
Creatinine Clearance 
Weight will be collected at the times shown in Table 6-1 through Table 6-2 to calculate CLcr. 
6.6.7. 
Adverse Events/Concomitant Medications/Protocol Restrictions 
Evaluation for AEs, review of concomitant medications, and review of protocol restrictions will 
occur at the times shown in Table 6-1 through Table 6-2 . See Section 7 for more infonn ation 
regarding AEs and Sections 4.3 and 5.7.1 for more infonnation about concomitant medications. 
6.7. 
Posttreatment Assessments 
All participants will be contacted by telephone 7 days ± 2 days after last dose of study drug for 
follow up(ie, on Day 24 [± 2] for Sequence AB or Day 27 [± 2] for Sequence BA). Study 
procedures and assessments are outlined in Table 6-1 and Table 6-2 . 
6.8. 
Assessments for Early Discontinuation from Study 
If a participant discontinues study treatment dosing (see Section 3.8), for example as a result of 
an AE, every attempt should be made to keep the participant and continue to perfonn procedures 
for stabilization per the investigator. Evaluations indicating abnonn al results believed to be 
possibly or probably related to study treatment at the early tennination visit should be repeated 
weekly or as often as deemed appropriate by the investigator until the abnonn ality resolves, 
returns to baseline visit levels, or is otherwise explained. 
If the participant withdraws consent from the study, the ET evaluations and/or procedures 
outlined in Table 6-1 through Table 6-2 should be perfonn ed within 72 hours of penn anently 
discontinuing the study. 
CONFIDENTIAL 
Page 45 
25 Septemeber 2020 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 46
25 Septemeber 2020
7.
ADVERSE EVENTS AND TOXICITY MANAGEMENT
7.1.
Definitions of Adverse Events and Serious Adverse Events
7.1.1.
Adverse Events
An AE is any untoward medical occurrence in a clinical study participant administered a study 
drug, which does not necessarily have a causal relationship with the treatment. An AE can,
therefore, be any unfavorable and/or unintended sign, symptom, or disease temporally associated 
with the use of a study drug, whether or not considered related to the study drug. Adverse events
may also include pretreatment or posttreatment complications that occur as a result of 
protocol-specified procedures, or special situations (Section 7.1.3). 
An AE does not include the following:

Medical or surgical procedures such as surgery, endoscopy, tooth extraction, and transfusion. 
The condition that led to the procedure may be an AE and must be reported.

Preexisting diseases, conditions, or laboratory abnormalities present or detected before the 
screening visit that do not worsen

Situations where an untoward medical occurrence has not occurred (eg, hospitalization for 
elective surgery, social and/or convenience admissions)

Overdose without clinical sequelae (see Section 7.1.3)

Any medical condition or clinically significant laboratory abnormality with an onset date 
before the consent form is signed and not related to a protocol-associated procedure is not an 
AE. It is considered to be preexisting and should be documented medical history.
Preexisting events that increase in severity or change in nature after study drug initiation or 
during or as a consequence of participation in the clinical study will also be considered AEs.
7.1.2.
Serious Adverse Events
An SAE is defined as an event that, at any dose, results in the following:

Death

A life-threatening situation (Note: 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.)

Inpatient hospitalization or prolongation of existing hospitalization


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 47
25 Septemeber 2020

Persistent or significant disability/incapacity

A congenital anomaly/birth defect

A medically important event or reaction; such events may not be immediately 
life-threatening or result in death or hospitalization but may jeopardize the participant or may 
require intervention to prevent 1 of the other outcomes constituting SAEs. Medical and 
scientific judgment must be exercised to determine whether such an event is a reportable 
under expedited reporting rules. Examples of medically important events include intensive 
treatment in an emergency room or at home for allergic bronchospasm; blood dyscrasias or 
convulsions that do not result in hospitalization; and development of drug dependency or 
drug abuse.
7.1.3.
Study Drugs and Gilead Concomitant Therapy Special Situations Reports
Special situation reports (SSRs) include all reports of medication error, abuse, misuse, overdose, 
occupational exposure, drug interactions, exposure via breastfeeding, unexpected benefit, 
transmission of infectious agents via the product, counterfeit of falsified medicine, and 
pregnancy regardless of an associated AE.
Medication error is any unintentional error in the prescribing, dispensing, preparation for 
administration or administration of a study drug while the medication is in the control of a health 
care professional, patient, or consumer. Medication errors may be classified as a medication error 
without an AE, which includes situations of missed dose, medication error with an AE, 
intercepted medication error, or potential medication error.
Abuse is defined as persistent or sporadic intentional excessive use of a study drug by a 
participant.
Misuse is defined as any intentional and inappropriate use of a study drug that is not in 
accordance with the protocol instructions or the local prescribing information.
An overdose is defined as an accidental or intentional administration of a quantity of a study 
drug given per administration or cumulatively which is above the maximum recommended dose 
as per protocol or in the product labeling (as it applies to the daily dose of the participant in 
question). In cases of a discrepancy in drug accountability, overdose will be established only 
when it is clear that the participant has taken the excess dose(s). Overdose cannot be established 
when the participant cannot account for the discrepancy, except in cases in which the 
investigator has reason to suspect that the participant has taken the additional dose(s).
Occupational exposure is defined as exposure to a study drug as a result of one’s professional or 
nonprofessional occupation.
Drug interaction is defined as any drug/drug, drug/food, or drug/device interaction.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 48
25 Septemeber 2020
Unexpected benefit is defined as an unintended therapeutic effect where the results are judged to 
be desirable and beneficial. 
Transmission of infectious agents is defined as any suspected transmission of an infected agent 
through a Gilead study drug.
Counterfeit or falsified medicine is defined as any study drug with a false representation of 
(a) its identity, (b) its source, or (c) its history.
7.2.
Assessment of Adverse Events and Serious Adverse Events
The investigator or qualified subinvestigator is responsible for assessing AEs and SAEs for 
causality and severity, and for final review and confirmation of accuracy of event information 
and assessments.
7.2.1.
Assessment of Causality for Study Drugs and Procedures
The investigator or qualified subinvestigator is responsible for assessing the relationship to the 
study drug using clinical judgment and the following considerations:

No: Evidence exists that the AE has an etiology other than the study drug. For SAEs, an 
alternative causality must be provided (eg, preexisting condition, underlying disease, 
intercurrent illness, concomitant medication).

Yes: There is reasonable possibility that the AE may have been caused by the study drug.
It should be emphasized that ineffective treatment should not be considered as causally related in 
the context of AE reporting. 
The relationship to study procedures (eg, invasive procedures such as venipuncture or biopsy) 
should be assessed using the following considerations:

No: Evidence exists that the AE has an etiology other than the study procedure.

Yes: The AE occurred as a result of protocol procedures (eg, venipuncture).
7.2.2.
Assessment of Severity 
The severity of AEs will be graded using the Common Terminology Criteria for Adverse Events
(CTCAE) Toxicity Grading Scale, Version 5. For each episode, the highest grade attained should
be reported as defined in the Toxicity Grading Scale (Appendix 4).


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 49
25 Septemeber 2020
7.3.
Investigator Reporting Requirements and Instructions
7.3.1.
Requirements for Collection Prior to Study Drug Initiation
After obtaining informed consent, but prior to initiation of study drug, the following types of 
events must be reported on the applicable eCRFs: all SAEs and AEs related to 
protocol-mandated procedures.
7.3.2.
Adverse Events
Following initiation of study treatment, collect all AEs, regardless of cause or relationship, until 
30 days after last administration of study drug and report to the eCRF database as instructed.
All AEs should be followed up until resolution or until the AE is stable, if possible. Gilead may 
request that certain AEs be followed beyond the protocol-defined follow-up period.
7.3.3.
Serious Adverse Events
All SAE and death, regardless of cause or relationship, that occurs after the participant
first consents to participate in the study (ie, signing the informed consent) and throughout the 
duration of the study, until 30 days after last administration of study drug must be reported on the 
applicable eCRFs and to Global Patient Safety (GLPS) as instructed below in this section. This 
also includes any SAEs resulting from protocol-associated procedures performed after informed 
consent is signed.
Investigators are not obligated to actively seek SAEs after the protocol-defined follow-up period;
however, if an investigator learns of any SAEs that occur after the protocol-defined follow-up 
period has concluded and the event is deemed relevant to the use of the study drug, the 
investigator should promptly document and report the event to GLPS.
Instructions for reporting SAEs are described in Section 7.4.1.
7.3.4.
Study Drug Special Situations Reports
All study drug SSRs that occur from study drug initiation and throughout the duration of the 
study, including the posttreatment follow-up visit, must be reported to GLPS (Section 7.4.2). 
Adverse events and SAEs resulting from SSRs must be reported in accordance to the AE and 
SAE reporting guidance (Section 7.3).
7.3.5.
Concomitant Therapy Reports
7.3.5.1.
Gilead Concomitant Therapy Special Situations Report
Special situation reports involving a Gilead concomitant therapy (not considered study drug), 
that occurs after the participant first consents to participate in the study (ie, signing the informed 
consent) and throughout the duration of the study, including the posttreatment follow-up phone 
call must be reported to GLPS utilizing the paper SSR (Section 7.4.2.3).


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 50
25 Septemeber 2020
7.3.5.2.
Non-Gilead Concomitant Therapy Report
Special situations involving non-Gilead concomitant medications do not need to be reported on 
the SSR form; however, for special situations that result in AEs due to a non-Gilead concomitant 
medication, the AE should be reported on the AE form. 
Any inappropriate use of concomitant medications prohibited by this protocol should not be 
reported as “misuse,” but may be more appropriately documented as a protocol deviation.
All clinical sequelae in relation to these SSRs will be reported as AEs or SAEs at the same time 
using the AE eCRF and/or the SAE report form. Details of the symptoms and signs, clinical 
management, and outcome will be reported, when available.
7.4.
Reporting Process for Serious Adverse Events and Special Situation Reports
7.4.1.
Serious Adverse Event Reporting Process

For fatal or life-threatening events, copies of hospital case reports, autopsy reports, and other 
documents are also to be transmitted by email or fax when requested and applicable. 
Transmission of such documents should occur without personal participant identification, 
maintaining the traceability of a document to the participant identifiers.

Additional information may be requested to ensure the timely completion of accurate safety 
reports.

Any medications necessary for treatment of the SAE must be recorded onto the concomitant 
medication section of the participant’s eCRF and the SAE narrative section of the Safety 
Report Form eCRF.
7.4.1.1.
Paper Serious Adverse Event Reporting Process

All SAEs will be recorded on the SAE report form and transmitted by emailing or faxing the 
report form within 24 hours of the investigator’s knowledge of the event to the attention of 
Gilead GLPS from ICF signature throughout the duration of the study, including the 
protocol-required posttreatment follow-up period.
Gilead GLPS:
Gilead GLPS 
Email
 
or
Fax: 
PPD
PPD


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 51
25 Septemeber 2020
7.4.2.
Special Situations Reporting Process 
7.4.2.1.
Paper Special Situations Reporting Process for Study Drug

All SSRs will be recorded on the special situations report form and transmitted by emailing 
or faxing the report form within 24 hours of the investigator’s knowledge of the event to the 
attention of Gilead GLPS from study drug initiation throughout the duration of the study, 
including the protocol-required post treatment follow-up period.
Gilead GLPS:
Gilead GLPS
Email: 
 
or
Fax: 
7.4.2.2.
Reporting Process for Gilead Concomitant Medications

Special situations that involve Gilead concomitant medications that are not considered study 
drug must be reported within 24 hours of the investigator’s knowledge of the event to Gilead 
GLPS utilizing the paper special situations report form to:
Gilead GLPS:
Gilead GLPS
Email:
 
or
Fax: 

Any inappropriate use of concomitant medications prohibited by this protocol should not be 
reported as “misuse,” but may be more appropriately documented as a protocol deviation.

Special situations involving non-Gilead concomitant medications do not need to be reported 
on the SSR form; however, special situations that result in AEs due to a non-Gilead 
concomitant medication, must be reported as an AE.
7.4.2.3.
Pregnancy Reporting Process

The investigator should report pregnancies in females, and/or female partners of male 
participants that are identified after initiation of study drug and throughout the study, 
including the protocol-required posttreatment follow-up period to be reported, to Gilead 
GLPS using the pregnancy report form within 24 hours of becoming aware of the pregnancy. 
Contact details for transmitting the pregnancy report form are as follows:
Gilead GLPS:
Gilead GLPS
Email: 
 
or
Fax: 
PPD
PPD
PPD
PPD
PPD
PPD


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 52
25 Septemeber 2020

The pregnancy itself is not considered an AE, nor is an induced elective abortion to terminate 
a pregnancy without medical reasons.

All other premature terminations of pregnancy (eg, a spontaneous abortion, an induced 
therapeutic abortion due to complications or other medical reasons) must be reported within 
24 hours as an SAE, as described in Section 7.4.1. The underlying medical reason for this 
procedure should be recorded as the AE term.

A spontaneous abortion is always considered to be an SAE and will be reported as described 
in Section 7.4.1. Furthermore, any SAE occurring as an adverse pregnancy outcome post 
study must be reported to the Gilead GLPS.

The participant should receive appropriate monitoring and care until the conclusion of the 
pregnancy. The outcome of the pregnancy/partner pregnancy should be reported to Gilead 
GLPS using the pregnancy outcome report form. If the end of the pregnancy/partner 
pregnancy occurs after the study has been completed, the outcome should be reported 
directly to Gilead GLPS. Gilead GLPS contact information is as follows: email: 
 and fax: 
. 

Refer to Appendix 2 for Pregnancy Precautions, Definition for Female of Childbearing 
Potential, and Contraceptive Requirements.
7.5.
Gilead Reporting Requirements
Depending on relevant local legislation or regulations, including the applicable FDA Code of 
Federal Regulations, the European Union Clinical Trials Directive (2001/20/EC) and relevant 
updates, and other country-specific legislation or regulations, Gilead may be required to expedite 
to worldwide regulatory agencies reports of SAEs which may be in the form of line-listings, 
serious adverse drug reactions, or SUSARs. In accordance with the European Union Clinical 
Trials Directive (2001/20/EC), Gilead or a specified designee will notify worldwide regulatory 
agencies and the relevant IEC in concerned member states of applicable SUSARs as outlined in 
current regulations.
Assessment of expectedness for SAEs will be determined by Gilead using reference safety 
information specified in the IB or relevant local label as applicable. 
All investigators will receive a safety letter notifying them of relevant suspected unexpected 
serious adverse reaction (SUSAR) reports associated with any study drug. The investigator 
should notify the IRB of SUSAR reports as soon as is practical, where this is required by local 
regulatory agencies, and in accordance with the local institutional policy. 
PPD
PPD


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 53
25 Septemeber 2020
7.6.
Clinical Laboratory Abnormalities and Other Abnormal Assessments as 
Adverse Events or Serious Adverse Events
Laboratory abnormalities without clinical significance are not to be recorded as AEs or SAEs. 
However, laboratory abnormalities (eg, clinical chemistry, hematology, urinalysis) that require 
medical or surgical intervention or lead to study drug interruption, modification, or 
discontinuation must be recorded as an AE, as well as an SAE, if applicable. In addition, 
laboratory or other abnormal assessments (eg, ECG, X-rays, vital signs) that are associated with 
signs and/or symptoms must be recorded as an AE or SAE if they meet the definition of an AE 
(or SAE) as described in Sections 7.1.1 and 7.1.2. If the laboratory abnormality is part of a 
syndrome, record the syndrome or diagnosis (eg, anemia) not the laboratory result (ie, decreased 
hemoglobin).
Severity should be recorded and graded according to the CTCAE Toxicity Grading Scale, 
Version 5 in Appendix 4. For AEs associated with laboratory abnormalities, the event should be 
graded on the basis of the clinical severity in the context of the underlying conditions; this may 
or may not be in agreement with the grading of the laboratory abnormality.
7.7.
Toxicity Management 
All clinical and clinically significant laboratory toxicities will be managed according to uniform 
guidelines detailed in Appendix 3, and as outlined below.
Grade 3 or 4 clinically significant laboratory abnormalities should be confirmed by repeat testing 
as soon as possible, and preferably within 3 calendar days after receipt of the original test results.
The Gilead medical monitor should be consulted prior to study drug discontinuation when 
medically feasible.
7.7.1.
Grades 1 and 2 Laboratory Abnormality or Clinical Event

Continue study drug at the discretion of the investigator.
7.7.2.
Grades 3 Laboratory Abnormality or Clinical Event

For a Grade 3 clinically significant laboratory abnormality or clinical event, the study drug
may be continued if the event is considered to be unrelated to the study drug.

For a Grade 3 clinically significant laboratory abnormality or clinical event confirmed by 
repeat testing, that is considered to be related to the study drug, then the study drug should be 
withheld until the toxicity returns to ≤Grade 2.

If a laboratory abnormality recurs to ≥Grade 3 following rechallenge with the study drug and 
is considered to be related to the study drug, then the study drug should be permanently 
discontinued and the participant managed according to local practice. Recurrence of 
laboratory abnormalities considered unrelated to the study drug may not require permanent 
discontinuation.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 54
25 Septemeber 2020
7.7.3.
Grades 4 Laboratory Abnormality or Clinical Event

For a Grade 4 clinically significant laboratory abnormality or clinical event confirmed by 
repeat testing, that is considered to be related to the study drug, the study drug should be 
permanently discontinued and the participant managed according to local practice. The 
participant should be followed as clinically indicated until the laboratory abnormality returns 
to baseline or is otherwise explained, whichever occurs first. A clinically significant Grade 4 
laboratory abnormality that is not confirmed by repeat testing should be managed according 
to the algorithm for the new toxicity grade.

Study drug may be continued without dose interruption for a clinically nonsignificant 
Grade 4 laboratory abnormality (eg, Grade 4 CK elevation after strenuous exercise, 
triglyceride elevation that is nonfasting or that can be medically managed) or a clinical event 
considered unrelated to the study drug.
Treatment-emergent toxicities will be noted by the investigator and brought to the attention of 
the Gilead medical monitor, and the appropriate course of action will be discussed and decided. 
Whether or not considered treatment related, all participants experiencing AEs must be 
monitored periodically until symptoms subside, any abnormal laboratory values have resolved or 
returned to baseline levels or they are considered irreversible, or until there is a satisfactory 
explanation for the changes observed.
Any questions regarding toxicity management should be directed to the Gilead medical monitor.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 55
25 Septemeber 2020
8.
STATISTICAL CONSIDERATIONS
8.1.
Analysis Objectives and Endpoints
8.1.1.
Analysis Objectives
The primary objectives of this study are as follows:

To evaluate the effect of filgotinib on a mixed OATP/CYP3A, OATP/ BCRP, and OATP 
substrates using phenotypic probes
The secondary objectives of this study are as follows:

To evaluate the safety and tolerability of multiple filgotinib doses administered alone or in 
combination with probe drugs.
8.1.2.
Primary Endpoint
The primary endpoint of this study is as follows:

PK parameters AUClast, AUCinf, and Cmax of ATV, PRA, and ROS. 
8.1.3.
Secondary Endpoint
The secondary endpoints of this study are as follows:

Incidences of AEs 

Laboratory abnormalities

Vital signs
8.2.
Planned Analyses
8.2.1.
Final Analysis
The final analysis will be performed after all participants have completed the study, outstanding 
data queries have been resolved or adjudicated as unresolvable, and the data have been cleaned 
and finalized.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 56
25 Septemeber 2020
8.3.
Analysis Conventions
8.3.1.
Analysis Sets
8.3.1.1.
All Randomized Analysis Set
The All Randomized Analysis Set includes all participants randomized into the study after 
screening. This is the primary analysis set for safety listings.
8.3.1.2.
Safety Analysis Set
The Safety Analysis Set will include all randomized participants who received at least 1 dose of 
study drug. Participants who received treatment other than that to which they were assigned will 
be analyzed according to the treatment received.
8.3.1.3.
Pharmacokinetics Analysis Set
The PK Analysis Set will include all randomized participants who received at least 1 dose of 
study drug and had at least 1 nonmissing PK concentration datum reported by PK laboratory for 
each respective analyte.
8.3.2.
Data Handling Conventions
For summary statistics, PK concentration values below the limit of quantitation will be treated as 
zero at predose and 1-half of the lower limit of quantitation (LLOQ) for postdose time points.
Laboratory data that are continuous in nature but are less than the LLOQ or above the upper limit 
of quantitation will be imputed to the value of the lower or upper limit minus or plus 
1 significant digit, respectively (eg, if the result of a continuous laboratory test is < 20, a value 
of 19 will be assigned; if the result of a continuous laboratory test is < 20.0, a value of 19.9 will 
be assigned).
Missing data can have an impact upon the interpretation of the study data. As this study is of 
short duration, it is anticipated that missing data will be minimal. In general, values for missing 
data will not be imputed. However, a missing pretreatment laboratory result would be treated as 
normal (ie, no toxicity grade) for the laboratory abnormality summary.
8.4.
Demographic Data and Baseline Characteristics
Demographic and baseline measurements will be summarized and descriptive statistics will be 
provided. 
Demographic summaries will include sex, race/ethnicity, and age.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 57
25 Septemeber 2020
8.5.
Safety Analysis
All safety data collected on or after the date that study drug was first administered up to 30 days
after last study drug administration will be summarized by treatment (according to the study drug 
received) using the Safety Analysis Set. 
8.5.1.
Extent of Exposure
A participant’s extent of exposure to study drug data will be generated from the study drug
administration data. Exposure data will be listed.
8.5.2.
Adverse Events
Clinical and laboratory AEs will be coded using the current version of the Medical Dictionary 
for Regulatory Activities (MedDRA). System organ class (SOC), high-level group term, 
high-level term, preferred term (PT), and lower-level term will be attached to the clinical 
database.
Treatment-emergent AEs (TEAEs), serious TEAEs, and TEAEs leading to discontinuation of 
treatment will be summarized by treatment, SOC, and PT using the current version of MedDRA. 
Adverse event data will be listed by participant.
8.5.3.
Laboratory Evaluations
Laboratory results and changes from predose values for selected laboratory tests will be 
summarized by treatment sequence at scheduled visits. The incidence of treatment-emergent 
graded laboratory abnormalities will be summarized by treatment. Listings of individual 
participant laboratory results will be provided.
8.5.4.
Other Safety Evaluations
Vital signs and ECG data will be summarized by treatment/treatment sequence..
8.6.
Pharmacokinetic Analysis
An analysis of variance (ANOVA) using a mixed-effects model with treatment, period, and 
sequence as fixed effects and participant as a random effect will be fitted to the natural 
logarithmic transformation of PK parameters (AUClast, AUCinf, Cmax) for each analyte. 
Two-sided 90% CIs will be calculated for the ratios of geometric least-squares means (GLSMs) 
of primary PK parameters between test (Treatment B) versus reference (Treatment A) 
treatments. 
Lack of PK interaction between the test and reference treatments will be concluded if the 
90% CIs for the GLSM ratios are contained within the 0.70 and 1.43 range for ATV, PRA, and 
ROS AUC and Cmax. Additional analyses may be performed if useful and appropriate.
Plasma concentrations and PK parameters AUClast, AUCinf, Cmax, %AUCexp, Clast, Tmax, Tlast, t1/2, 
CL/Z, λz and Vz/F will be listed and summarized for ATV, PRA, and ROS using descriptive 
statistics by treatment. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 58
25 Septemeber 2020
8.7.
Sample Size
With 26 evaluable participants, the estimated two-sided 90% CI of the GLSM ratio of test versus 
reference treatments, with regards to AUCinf, AUClast, and Cmax, will be within [70%, 143%] with 
≥ 85% probability, if the true GLSM ratio is 1.0. This is assuming a standard deviation (SD) of 
differences of no more than 0.569 on a natural logarithm scale, supported by PK data from Study 
GS-US-402-2102. With 4 participants for overage, a total sample size of 30 participants will be 
required.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 59
25 Septemeber 2020
9.
RESPONSIBILITIES
9.1.
Investigator Responsibilities
9.1.1.
Good Clinical Practice
The investigator will ensure that this study is conducted in accordance with International Council 
for Harmonisation (of Technical Requirements for Pharmaceuticals for Human Use) (ICH)
E6(R2) GCP and applicable laws and regulations.
9.1.2.
Financial Disclosure
The investigator and subinvestigators will provide documentation of their financial interest or 
arrangements with Gilead or proprietary interests in the study drug under study. This 
documentation must be provided prior to the investigator’s (and any subinvestigator’s) 
participation in the study. The investigator and subinvestigator agree to notify Gilead of any 
change in reportable interests during the study and for 1 year following completion of the study. 
Study completion is defined as the date when the last participant completes the protocol-defined 
activities.
9.1.3.
Institutional Review Board Review and Approval
The investigator (or sponsor as appropriate according to local regulations) will submit this 
protocol, ICF, and any accompanying material to be provided to the participant (such as 
advertisements, participant information sheets, or descriptions of the study used to obtain 
informed consent) to an IRB. The investigator will not begin any study participant activities until 
approval from the IRB has been documented and provided as a letter to the investigator and 
documentation of the approval is provided to the investigator.
Before implementation, the investigator will submit to and receive documented approval from 
the IRB for any modifications made to the protocol or any accompanying material to be provided 
to the participant after initial IRB approval, with the exception of those necessary to reduce 
immediate risk to study participants.
9.1.4.
Informed Consent
The investigator is responsible for obtaining written informed consent from each individual 
participating in this study after adequate explanation of the aims, methods, objectives, and 
potential hazards of the study before undertaking any study-related procedures. The investigator 
must use the most current IRB-approved ICF for documenting written informed consent. Each 
ICF will be appropriately signed and dated by the participant, the person conducting the consent 
discussion, and also by an impartial witness if required by IRB or local requirements. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 60
25 Septemeber 2020
The ICF will inform participants about genomic testing and/or planned sample 
retentionConfidentiality
The investigator must ensure that participants’ anonymity will be strictly maintained and that 
their identities are protected from unauthorized parties. Only an identification code and any other 
unique identifier(s) as allowed by local law (such as year of birth) will be recorded on any form 
or biological sample submitted to the sponsor, IRB, or the laboratory. Laboratory specimens 
must be labeled in such a way as to protect participant identity while allowing the results to be 
recorded to the proper participant. Refer to specific laboratory instructions. NOTE: The 
investigator must keep a screening log showing codes, names, and addresses for all participants 
screened and for all participants enrolled in the study. Participant data will be processed in 
accordance with all applicable regulations. 
The investigator agrees that all information received from Gilead, including but not limited to the 
IB, this protocol, eCRF, study drug information, and any other study information, remain the 
sole and exclusive property of Gilead during the conduct of the study and thereafter. This 
information is not to be disclosed to any third party (except employees or agents directly 
involved in the conduct of the study or as required by law) without prior written consent from 
Gilead. The investigator further agrees to take all reasonable precautions to prevent the 
disclosure by any employee or agent of the study site to any third party or otherwise into the 
public domain.
9.1.5.
Study Files and Retention of Records
The investigator must maintain adequate and accurate records to enable the conduct of the study 
to be fully documented and the study data to be subsequently verified. These documents should 
be classified into at least the following 2 categories: (1) investigator’s study file and 
(2) participant clinical source documents.
The investigator’s study file will contain the protocol/amendments, eCRF, IRB governmental 
approval with correspondence, ICF, drug records, staff curriculum vitae and authorization forms, 
and other appropriate documents and correspondence.
The required source data should include sequential notes containing at least the following 
information for each participant:

Participant identification (name, date of birth, gender)

Documentation that participant meets eligibility criteria, ie, history, physical examination, 
and confirmation of diagnosis (to support inclusion and exclusion criteria)

Documentation of the reason(s) a consented participant is not enrolled

Participation in study (including study number)

Study discussed and date of informed consent


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 61
25 Septemeber 2020

Dates of all visits

Documentation that protocol-specific procedures were performed

Results of efficacy parameters, as required by the protocol

Start and end dates (including dose regimen) of study drug, including dates of dispensing and 
return

Record of all AEs and other safety parameters (start and end date; causality and severity), 
and documentation that adequate medical care has been provided for any AE

Concomitant medication (including start and end dates, dose if relevant, and dose changes)

Date of study completion and reason for early discontinuation, if it occurs
All clinical study documents must be retained by the investigator for at least 2 years or according 
to local laws, whichever is longer, after the last approval of a marketing application in an ICH 
region (ie, US, Europe, or Japan) and until there are no pending or planned marketing 
applications in an ICH region; or, if no application is filed or if the application is not approved 
for such indication, for 2 years after the investigation is discontinued and regulatory authorities 
have been notified. Investigators may be required to retain documents longer if specified by 
regulatory requirements, by local regulations, or by an agreement with Gilead. The investigator 
must notify Gilead before destroying any clinical study records.
Should the investigator wish to assign the study records to another party or move them to another 
location, Gilead must be notified in advance.
If the investigator cannot provide for this archiving requirement at the study site for any or all of 
the documents, special arrangements must be made between the investigator and Gilead to store 
these records securely away from the site so that they can be returned sealed to the investigator 
in case of an inspection. When source documents are required for the continued care of the 
participant, appropriate copies should be made for storage away from the site.
9.1.6.
Case Report Forms
For each participant enrolled, an eCRF will be completed by an authorized study staff member 
whose training for this function is documented according to study procedures. The eCRF should 
be completed on the day of the participant visit to enable the sponsor to perform central 
monitoring of safety data, whenever possible. The Eligibility Criteria eCRF should be completed 
only after all data related to eligibility have been received and the participant has been enrolled. 
Subsequent to data entry, a study monitor will perform source data verification SDV within the 
EDC system. Original entries as well as any changes to data fields will be stored in the audit trail 
of the system. Prior to database lock (or any interim time points as described in the clinical data 
management plan), the investigator will use his/her login credentials to confirm that the forms 
have been reviewed, and that the entries accurately reflect the information in the source 
documents. The eCRF captures the data required per the protocol schedule of events and 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 62
25 Septemeber 2020
procedures. System-generated or manual queries will be issued to the investigative site staff as 
data discrepancies are identified by the monitor or internal Gilead staff who routinely review the 
data for completeness, correctness, and consistency. The site coordinator is responsible for 
responding to the queries in a timely manner, within the system, either by confirming the data as 
correct or updating the original entry, and providing the reason for the update (eg, data entry 
error). At the conclusion of the study, Gilead will provide the site with a read-only archive copy 
of the data entered by that site. This archive must be stored in accordance with the records 
retention requirements outlined in Section 9.1.5.
9.1.7.
Investigator Inspections
The investigator will make available all source documents and other records for this study to 
Gilead’s appointed study monitors, to IRB, or to regulatory authority or health authority 
inspectors.
9.1.8.
Protocol Compliance
The investigator is responsible for ensuring the study is conducted in accordance with the 
procedures and evaluations described in this protocol.
9.2.
Sponsor Responsibilities
9.2.1.
Protocol Modifications
Protocol modifications, except those intended to reduce immediate risk to study participants, 
may be made only by Gilead. The investigator must submit all protocol modifications to IRB in 
accordance with local requirements and receive documented IRB approval before modifications 
may be implemented.
9.2.2.
Study Report and Publications
A clinical study report will be prepared and provided to the regulatory agency. Gilead will ensure 
that the report meets the standards set out in the ICH Guideline for Structure and Content of 
Clinical Study Reports (ICH E3). Note that an abbreviated report may be prepared in certain 
cases. 
Investigators in this study may communicate, orally present, or publish in scientific journals or 
other scholarly media only after the following conditions have been met:
The results of the study in their entirety have been publicly disclosed by or with the consent of 
Gilead in an abstract, manuscript, or presentation form or the study has been completed at all 
study sites for at least 2 years.
The investigator will submit to Gilead any proposed publication or presentation along with the 
respective scientific journal or presentation forum at least 30 days before submission of the 
publication or presentation. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 63
25 Septemeber 2020
No such communication, presentation, or publication will include Gilead’s confidential 
information (see Section 9.1.5).
The investigator will comply with Gilead’s request to delete references to its confidential 
information (other than the study results) in any paper or presentation and agrees to withhold 
publication or presentation for an additional 60 days in order to obtain patent protection if 
deemed necessary.
9.3.
Joint Investigator/Sponsor Responsibilities
9.3.1.
Payment Reporting
Investigators and their study staff may be asked to provide services performed under this 
protocol (eg, attendance at investigator's meetings). If required under the applicable statutory and 
regulatory requirements, Gilead will capture and disclose to federal and state agencies any 
expenses paid or reimbursed for such services, including any clinical study payments, meal, 
travel expenses or reimbursements, consulting fees, and any other transfer of value.
9.3.2.
Access to Information for Monitoring
In accordance with regulations and guidelines, the medical monitor must have direct access to 
the investigator’s source documentation in order to verify the accuracy of the data recorded in 
the eCRF.
The monitor is responsible for routine review of the eCRF at regular intervals throughout the 
study to verify adherence to the protocol and the completeness, consistency, and accuracy of the 
data being entered on them. The monitor should have access to any participant records needed to 
verify the entries on the eCRF. The investigator agrees to cooperate with the monitor to ensure 
that any problems detected through any type of monitoring (central, onsite) are resolved.
9.3.3.
Access to Information for Auditing or Inspections
Representatives of regulatory authorities or Gilead may conduct inspections or audits of the 
clinical study. If the investigator is notified of an inspection by a regulatory authority the 
investigator agrees to notify the Gilead medical monitor immediately. The investigator agrees to 
provide to representatives of a regulatory agency or Gilead access to records, facilities, and 
personnel for the effective conduct of any inspection or audit.
9.3.4.
Study Discontinuation
Both Gilead and the investigator reserve the right to terminate the study at any time. Should this 
be necessary, both parties will arrange discontinuation procedures and notify the particpants, 
appropriate regulatory authority, and IRBs. In terminating the study, Gilead and the investigator 
will ensure that adequate consideration is given to the protection of the participants’ interests.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 64
25 Septemeber 2020
10.
REFERENCES
Chu X, Liao M, Shen H, Yoshida K, Zur AA, Arya V, et al. Clinical Probes and Endogenous 
Biomarkers as Substrates for Transporter Drug-Drug Interaction Evaluation: 
Perspectives From the International Transporter Consortium. Clin Pharmacol 
Ther 2018;104 (5):836-64.
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 
1976;16:31-41.
Elsby R, Hilgendorf C, Fenner K. Understanding the critical disposition pathways of statins to 
assess drug-drug interaction risk during drug development: it's not just about 
OATP1B1. Clin Pharmacol Ther 2012;92 (5):584-98.
Giacomini KM, Huang SM, Tweedie DJ, Benet LZ, Brouwer KL, Chu X, et al. Membrane 
transporters in drug development. Nat Rev Drug Discov 2010;9 (3):215-36.
Huang SM, Woodcock J. Transporters in drug development: advancing on the Critical Path. Nat 
Rev Drug Discov 2010;9 (3):175-6.
Mease P, Coates LC, Helliwell PS, Stanislavchuk M, Rychlewska-Hanczewska A, Dudek A, et 
al. Efficacy and Safety of Filgotinib, a Selective Januse Kinase 1 Inhibitor, in 
Patients with Active Psoriatic Arthritis (EQUATOR): Results from a 
Randomized, Placebo-Controlled Phase 2 Trial. Lancet 2018;392:2367-77.
Meyer zu Schwabedissen HE, Kim RB. Hepatic OATP1B transporters and nuclear receptors 
PXR and CAR: interplay, regulation of drug disposition genes, and single 
nucleotide polymorphisms. Mol Pharm 2009;6 (6):1644-61.
Neuvonen PJ. Drug interactions with HMG-CoA reductase inhibitors (statins): the importance of 
CYP enzymes, transporters and pharmacogenetics. Curr Opin Investig Drugs 
2010;11 (3):323-32.
Pasanen MK, Fredrikson H, Neuvonen PJ, Niemi M. Different effects of SLCO1B1 
polymorphism on the pharmacokinetics of atorvastatin and rosuvastatin. Clin 
Pharmacol Ther 2007;82 (6):726-33.
van der Heijde D, Baraliakos X, Gensler LS, Maksymowych WP, Tseluyko V, Nadashkevich O, 
et al. Efficacy and Safety of Filgotinib, a Selective Janus Kinase 1 Inhibitor, in 
Patients with Active Ankylosing Spondylitis (TORTUGA): Results from a 
Randomized Placebo-Controlled, Phase 2 Trial. Lancet 2018;392:2378 87.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 65
25 Septemeber 2020
11.
APPENDICES
Appendix 1.
Investigator Signature Page
Appendix 2.
Pregnancy Precautions, Definition for Female of Childbearing Potential, and 
Contraceptive Requirements
Appendix 3.
Management of Clinical and Laboratory Adverse Events
Appendix 4.
Common Terminology Criterial for Adverse Events (CTCAE) Grading Scale v5.0


Filgotinib 
 
Protocol GS-US-417-5937 
Final 
Gilead Sciences, Inc.  
Original 
CONFIDENTIAL 
Page 66 
 
25 Septemeber 2020 
Appendix 1. 
Investigator Signature Page 
 
Gilead Sciences, Inc. 
333 Lakeside Drive 
Foster City, CA 94404 
USA 
 
STUDY ACKNOWLEDGEMENT 
 
A Phase 1 Study to Evaluate OATP Transporter-Mediated Drug-Drug Interactions Between 
Filgotinib and Stains as Probe Drugs in Healthy Participants 
Original Protocol, 25 Septemeber 2020 
This protocol has been approved by Gilead Sciences, Inc. The following signature documents 
this approval. 
 
Name (Printed) 
Responsible Person’s Title 
 
Signature 
 
 
 
 
Date 
 
 
INVESTIGATOR STATEMENT 
 
I have read the protocol, including all appendices, and I agree that it contains all necessary 
details for me and my staff to conduct this study as described. I will conduct this study as 
outlined herein and will make a reasonable effort to complete the study within the time 
designated. 
I will provide all study personnel under my supervision copies of the protocol and access to all 
information provided by Gilead Sciences, Inc. I will discuss this material with them to ensure 
that they are fully informed about the drugs and the study. 
 
 
 
Principal Investigator Name (Printed) 
 
Signature 
 
 
 
 
Date 
 
Site Number 
 
25 September 2020
PPD
PPD


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 67
25 Septemeber 2020
Appendix 2.
Pregnancy Precautions, Definition for Female of Childbearing 
Potential, and Contraceptive Requirements
1) Definitions
a. Definition of Childbearing Potential
For the purposes of this study, a female born participant is considered of childbearing potential 
following the initiation of puberty (Tanner stage 2) until becoming postmenopausal unless the 
participant is permanently sterile or has medically documented ovarian failure.
Women are considered to be in a postmenopausal state when they are ≥54 years of age with 
cessation of previously occurring menses for ≥12 months without an alternative cause. In 
addition, women < 54 years of age with amenorrhea of ≥12 months may also be considered 
postmenopausal if their follicle-stimulating hormone (FSH) level is in the postmenopausal range 
and they are not using hormonal contraception or hormonal replacement therapy.
Permanent sterilization includes hysterectomy, bilateral oophorectomy, or bilateral 
salpingectomy in a female participant of any age.
b. Definition of Male Fertility
For the purposes of this study, a male born participant is considered fertile after the initiation of 
puberty unless the participant is permanently sterile by bilateral orchidectomy or medical 
documentation.
2) Contraception Requirements for Female Participants
a. Study Drug Effects on Pregnancy and Hormonal Contraception
Filgotinib is contraindicated in pregnancy as a malformative effect has been 
demonstrated/suspected or is unknown taking into consideration class effect and/or strong 
suspicion of human teratogenicity/fetotoxicity in early pregnancy based on nonclinical data. Data 
from clinical PK interaction studies of filgotinib have demonstrated that there is no reduction in 
the clinical efficacy of hormonal contraception. Refer to the latest version of the IB for additional 
information.
b. Contraception Requirements for Female Participants of Childbearing Potential
The inclusion of female participants of childbearing potential requires the use of highly effective 
contraceptive measures with a failure rate of < 1% per year. They must have a negative serum 
pregnancy test at screening and admission and a urine negative pregnancy test at the Admission 
(Day 1) prior to randomization. Pregnancy tests will be performed as specified in the protocol.
Female participants of childbearing potential must agree to use one of the contraceptive methods 
below from Screening until 1 week after the last dose of study drug.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 68
25 Septemeber 2020

Complete abstinence from intercourse of reproductive potential. Abstinence is an acceptable 
method of contraception only when it is in line with the participant’s preferred and usual 
lifestyle. 
Or
Consistent and correct use of 1 of the following methods of birth control listed below: 

Hormonal or non-hormonal intrauterine device (IUD) 

Subdermal contraceptive implant

Bilateral tubal occlusion (upon medical assessment of surgical success)

Vasectomy in the male partner (upon medical assessment of surgical success)
Or 
Female participants who wish to use a hormonally-based method must use it in conjunction with 
a barrier method, preferably a male condom. Hormonal methods are restricted to those associated 
with the inhibition of ovulation. Hormonally-based contraceptives and barrier methods permitted 
for use in this protocol are as follows:

Hormonal methods (each method must be used with a barrier method, preferably male 
condom)
Oral contraceptives (either combined or progesterone only)
Injectable progesterone
Transdermal contraceptive patch
Contraceptive vaginal ring

Barrier methods (each method must be used with a hormonal method)
Male condom (with or without spermicide)
Female condom (with or without spermicide)
Diaphragm with spermicide
Cervical cap with spermicide
Sponge with spermicide


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 69
25 Septemeber 2020
Inclusion of methods of contraception in this list of permitted methods does not imply that the 
method is approved in any country or region. Methods should only be used if locally approved. 
Female participants must also refrain from egg donation and in vitro fertilization during 
treatment and until the end of the contraceptive requirement.
3) Contraception Requirements for Male Participants
It is theoretically possible that a relevant systemic concentration of study drug may be achieved 
in a female partner from exposure of the male participant’s seminal fluid and poses a potential 
risk to an embryo/fetus. Therefore, male participants with female partners of childbearing 
potential must use condoms during treatment until 1 week after last dose of study drug. 
4) Unacceptable Birth Control Methods
Birth control methods that are unacceptable include periodic abstinence (eg, calendar, ovulation, 
symptothermal, postovulation methods), withdrawal (coitus interruptus), spermicides only, and 
lactational amenorrhea method. A female condom and a male condom should not be used 
together.
5) Procedures to be Followed in the Event of Pregnancy
Female participants will be instructed to notify the investigator if they become pregnant or 
suspect they are pregnant at any time from start of the study to 1 week after the last dose of study 
drug.
Male subjects whose partner has become pregnant or suspects she is pregnant from start of study 
through one week after last dose of study drug must also report the information to the 
investigator.
Study drug must be discontinued immediately upon discussion with the medical monitor.
Instructions for reporting pregnancy, partner pregnancy, and pregnancy outcome are outlined in 
Section 7.4.2.3.


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 70
25 Septemeber 2020
Appendix 3.
Management of Clinical and Laboratory Adverse Events
Grade 1 
Grade 2 
Grade 3 
Continue study drug dosing at the 
discretion of the investigator 
Repeat lab to confirm toxicity 
grade 
If confirmed, and possibly or probably related to study drug(s): 
If confirmed and 
unrelated to study 
drug(s), dosing may 
continue at the 
discretion of the 
investigator. 
1. Withhold study drug(s) until !s Grade 2 
2. 
Restart all study drug(s) at full dose upon discussion with the 
Gilead Medical Monitor 
If Grade 3 or 4 recurrence is 
confirmed and possibly or 
probably related to study drug(s), 
discontinue all study drug(s) 
permanently, and manage the 
subject according to local practice. 
If Grade 3 or 4 recurrence is 
confirmed and unrelated to 
study drug(s), continue all 
investigational medicinal 
product(s) at the same dose at 
the discretion of the 
investigator. 
Grade 4 
If confirmed, and 
possibly or probably 
related to study 
drug(s), discontinue 
study(s) dosing 
permanently, and 
manage subject 
according to local 
practice. Subject 
should be followed as 
clinically indicated 
until the laboratory 
abnormality returns to 
baseline, or is 
otherwise explained. 


Filgotinib
Protocol GS-US-417-5937
Final
Gilead Sciences, Inc.
Original
CONFIDENTIAL
Page 71
25 Septemeber 2020
Appendix 4.
Common Terminology Criterial for Adverse Events (CTCAE)
Grading Scale v5.0
https://ctep.cancer.gov/protocolDevelopment/electronic_applications/ctc.htm#ctc_50

SAP_001.pdf: 
STATISTICAL ANALYSIS PLAN
Study Title:
A Phase 1 Study to Evaluate OATP Transporter-Mediated 
Drug-Drug Interactions Between Filgotinib and Statins as Probe 
Drugs in Healthy Participants
Study Phase 
1
Name of Test Drug:
Filgotinib
Study Number:
GS-US-417-5937
Sponsor:
Gilead Sciences, Inc.
Protocol Version (Date):
Original (25 September 2020) 
Analysis Type:
Final Analysis
Analysis Plan Version:
Version 1.0
Analysis Plan Date:
23 February 2021
Analysis Plan Author(s):
CONFIDENTIAL AND PROPRIETARY INFORMATION
PPD
(rJ GILEAU 
-


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 2
23 February 2021
TABLE OF CONTENTS
TABLE OF CONTENTS................................................................................................................................................2
LIST OF IN-TEXT TABLES .........................................................................................................................................3
LIST OF IN-TEXT FIGURES........................................................................................................................................3
1.
INTRODUCTION..................................................................................................................................................6
1.1.
Study Objectives........................................................................................................................................6
1.2.
Study Endpoints.........................................................................................................................................6
1.3.
Study Design .............................................................................................................................................6
1.4.
Sample Size and Power .............................................................................................................................9
2.
TYPE OF PLANNED ANALYSIS.......................................................................................................................10
2.1.
Data Monitoring Committee Analyses ....................................................................................................10
2.2.
Interim Analysis ......................................................................................................................................10
2.3.
Final Analysis..........................................................................................................................................10
2.4.
Changes from Protocol-Specified Analysis.............................................................................................10
3.
GENERAL CONSIDERATIONS FOR DATA ANALYSES ................................................................................11
3.1.
Analysis Sets ...........................................................................................................................................11
3.1.1.
All Randomized Analysis Set................................................................................................11
3.1.2.
Safety Analysis Set................................................................................................................11
3.1.3.
Pharmacokinetic Analysis Set ...............................................................................................11
3.2.
Missing Data and Outliers .......................................................................................................................11
3.2.1.
Missing Data..........................................................................................................................11
3.2.2.
Outliers ..................................................................................................................................12
3.3.
Data Handling Conventions and Transformations...................................................................................12
3.4.
Visit Windows.........................................................................................................................................13
3.4.1.
Definition of Predose, Postdose, Study day, and Treatment Day .........................................13
3.4.2.
Analysis Window ..................................................................................................................14
3.4.3.
Selection of Data in the Event of Multiple Records on the Same Day..................................14
4.
SUBJECT DISPOSITION....................................................................................................................................16
4.1.
Subject Enrollment and Disposition........................................................................................................16
4.2.
Extent of Exposure ..................................................................................................................................16
4.3.
Protocol Deviations .................................................................................................................................17
5.
BASELINE CHARACTERISTICS......................................................................................................................18
5.1.
Demographics..........................................................................................................................................18
5.2.
Other Baseline Characteristics.................................................................................................................18
5.3.
Medical History.......................................................................................................................................18
6.
EFFICACY ANALYSES......................................................................................................................................19
7.
SAFETY ANALYSES..........................................................................................................................................20
7.1.
Adverse Events and Deaths .....................................................................................................................20
7.1.1.
Adverse Event Dictionary......................................................................................................20
7.1.2.
Adverse Event Severity .........................................................................................................20
7.1.3.
Relationship of Adverse Events to Study Drug.....................................................................20
7.1.4.
Relationship of Adverse Events to Study Procedure.............................................................20
7.1.5.
Serious Adverse Events.........................................................................................................20
7.1.6.
Treatment-Emergent Adverse Events....................................................................................21


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 3
23 February 2021
7.1.7.
Summaries of Adverse Events and Deaths............................................................................21
7.1.8.
Additional Analysis of Adverse Events ................................................................................22
7.2.
Laboratory Evaluations............................................................................................................................23
7.2.1.
Summaries of Numeric Laboratory Results ..........................................................................23
7.2.2.
Graded Laboratory Values.....................................................................................................24
7.2.3.
Liver-Related Laboratory Evaluations ..................................................................................25
7.3.
Body Weight, Height, BMI, and Vital Signs...........................................................................................25
7.4.
Prior and Concomitant Medications ........................................................................................................26
7.5.
Electrocardiogram Results.......................................................................................................................26
7.6.
Other Safety Measures.............................................................................................................................26
7.7.
Changes From Protocol-Specified Safety Analyses ................................................................................26
8.
PHARMACOKINETIC EVALUATION/ANALYSIS .........................................................................................28
8.1.
Estimation of Pharmacokinetic Parameters .............................................................................................28
8.1.1.
Pharmacokinetic Parameters..................................................................................................28
8.1.2.
Statistical Analysis Method...................................................................................................29
8.1.3.
Sensitivity Analysis...............................................................................................................31
8.1.4.
Changes From Protocol-Specified PK Analyses ...................................................................32
9.
REFERENCES .....................................................................................................................................................33
10.
SOFTWARE .........................................................................................................................................................34
11.
SAP REVISION...................................................................................................................................................35
12.
APPENDICES......................................................................................................................................................36
LIST OF IN-TEXT TABLES
Table 1-1.
Treatment Schema .....................................................................................................................7
Table 8-1.
Study Treatments and Associated Analytes.............................................................................28
Table 8-2.
Pharmacokinetic Parameters for Each Analyte........................................................................29
Table 8-3.
Statistical Comparisons for Pharmacokinetic Analyses ..........................................................31
LIST OF IN-TEXT FIGURES
Figure 1-1.
Study Schema – Sequence AB ..................................................................................................8
Figure 1-2.
Study Schema – Sequence BA ..................................................................................................8


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 4
23 February 2021
LIST OF ABBREVIATIONS
AE
adverse event
ATV
atorvastatin
BLQ
below the limit of quantitation
BCRP
breast cancer resistance proteins
BMI
body mass index
CI
confidence interval
COVID-19 RT-PCR
a real-time reverse transcription polymerase chain reaction (rTT-PCR) test for the 
qualitative detection of nucleic acid from SARS-CoV-2
CRF
case report form
CSR
clinical study report
CTCAE 
Common Terminology Criteria for Adverse Events
CV
coefficient of variation
CYP3A
cytochrome P450 3A
DDI
drug-drug interaction
DMC
data monitoring committee
ECG
electrocardiogram
eCRF
electronic case report form
ET
early termination
FIL
filgotinib
Gilead
Gilead Sciences
GLSM
geometric least-squares mean
LLOQ
lower limit of quantitation
LOQ
limit of quantitation
MedDRA
Medical Dictionary for Regulatory Activities
OATP
organic anion transporting polypeptide
PT
preferred term
PRO
pravastatin
Q1, Q3
first quartile, third quartile
RA
rheumatoid arthritis
ROS
rosuvastatin
SAP
statistical analysis plan
SD
standard deviation
SI
International System of Units (Systeme International d’Unites)
SOC
system organ class
TEAE
treatment-emergent adverse events
TFLs
tables, figures, and listings
TOST
two one-sided tests
ULOQ
upper limit of quantitation
WHO
World Health Organization


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 5
23 February 2021
PHARMACOKINETIC ABBREVIATIONS
λz
terminal elimination rate constant, estimated by linear regression of the terminal elimination 
phase of the log plasma/serum concentration of drug versus time curve of the drug
%AUCexp
percentage of AUC extrapolated between AUClast and AUCinf
AUC
area under the plasma/serum concentration versus time curve
AUClast
area under the plasma/serum concentration versus time curve from time zero to the last 
quantifiable concentration
AUCinf
area under the plasma/serum concentration versus time curve extrapolated to infinite time, 
calculated as AUClast + (Clast /λz )
AUCxxx
partial area under the plasma/serum concentration versus time curve from time “x” to time “xx”
CL/F
apparent oral clearance after administration of the drug: CL/F = Dose/ AUCinf, where “Dose” is 
the dose of the drug
Clast
last observed quantifiable plasma/serum concentration of the drug
Cmax
maximum observed plasma/serum concentration of drug
Cmin
minimum observed plasma/serum concentration of drug
PK
    pharmacokinetic(s)
t½
estimate of the terminal elimination half-life of the drug in plasma/serum, calculated by 
dividing the natural log of 2 by the terminal elimination rate constant (λz)
Tlast
time (observed time point) of Clast
Tmax
time (observed time point) of Cmax


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 6
23 February 2021
1.
INTRODUCTION
This statistical analysis plan (SAP) describes the statistical analysis methods and data 
presentations to be used in tables, figures, and listings (TFLs) in the clinical study report (CSR) 
for Study GS-US-417-5937. This SAP is based on the original study protocol dated 
25 September 2020 and the electronic case report form (eCRF). The SAP will be finalized prior 
to database finalization. Any changes made after finalization of the SAP will be documented in 
the CSR.
1.1.
Study Objectives
The primary objective of this study is as follows:

To evaluate the effect of filgotinib (FIL) on a mixed organic anion transporting 
polypeptide/cytochrome P450 3A (OATP/CYP3A), organic anion transporting polypeptide/ 
breast cancer resistance protein (OATP/BCRP), and OATP substrates using phenotypic 
probes
The secondary objective of this study is as follows:

To evaluate the safety and tolerability of multiple filgotinib doses administered alone or in 
combination with probe drugs.
1.2.
Study Endpoints
The primary endpoints are the pharmacokinetic (PK) parameters: AUClast, AUCinf, and Cmax of 
atorvastatin (ATV), ATV’s metabolite (2-OH-ATV), pravastatin (PRA), and rosuvastatin (ROS).
The secondary endpoints are as follows:

Incidences of adverse events (AEs)

Laboratory abnormalities

 Vital signs
1.3.
Study Design
This study is a Phase 1, randomized, two-way crossover, open-label, single and multiple dose, 
single center study to evaluate the effect of filgotinib on a mixed OATP/CYP3A, OATP/BCRP, 
and OATP substrates using phenotypic probes in healthy normal subjects. Up to 30 subjects will 
enrolled. 
Healthy surgically sterile male and nonpregnant, nonlactating female subjects aged 18 through 
55 years old will be enrolled into the study. 


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 7
23 February 2021
Following completion of screening and admission assessments (Day −1), eligible subjects will be 
randomized at 1:1 ratio on the evening of Day −1 to receive 1 of 2 treatment sequences starting 
on Day 1. Subjects will dose for 13 days. The treatment end dates are on Day 17 (Sequence AB) 
or Day 20 (Sequence BA). The completion of assessments is on Day 17 (Sequence AB) or 
Day 23 (Sequence BA). All subjects will be contacted by telephone 7 (± 2) days after last dose 
for follow up. The treatment schema is shown below in Figure 1-1. 
The study drugs and treatments are as follows:
OATP/CYP3A substrate: Atorvastatin (ATV) 40 mg 
OATP substrate: Pravastatin (PRA) 40 mg
OATP/BCRP substrate: Rosuvastatin (ROS) 10 mg
Pravastatin/Rosuvastatin (PRA/ROS) will be coadministered as a probe cocktail.
Treatment A: Single dose of ATV 40 mg, followed by a washout period of 1 day and then a 
single dose of the PRA 40 mg/ROS 10 mg cocktail. All agents should be administered in the 
morning under fasted conditions.
Treatment B: Filgotinib 200 mg administered once daily for 11 days, with a single dose of ATV 
40 mg administered on the sixth day followed by a single dose of PRA 40 mg/ROS 10 mg 
cocktail administered on the eighth day. All agents should be administered in the morning under 
fasted conditions.
Table 1-1.
Treatment Schema
Sequence
Days
Period 1
Period 2
1
2
3
4-6
7-
11
12
13
14
15-17
AB
ATV
WO
PRA + 
ROS
WO
FIL
FIL+ 
ATV
FIL
FIL + PRA 
+ ROS
FIL
Period 1
Period 2
1-5
6
7
8
9-
11
12-
17
18
19
20
BA
FIL
FIL + 
ATV
FIL
FIL + PRA + 
ROS
FIL
WO
ATV
WO
PRA + 
ROS
FIL = filgotinib; ATV = atorvastatin; PRA = pravastatin; ROS = rosuvastatin; WO=wash out
An overview of the study design is described below and shown in Figure 1-1 and Figure 1-2.


Filgotinib 
GS-US-417-5937 
Statistical Analysis Plan 
Version 1. 0 
Figure 1-1. 
Study Schema - Sequence AB 
-28 
-1 
17 
24(±2) 
1 
3 
7 
11 12 13 14 15 16 
Screening 
Admission 
6, • 
• •• 
-• 
6. • 
I 
Figure 1-2. 
-28 
Clinic Confinement 
Intensive PK sampling 
Filgotinib 
Atorvastatin 
Pravastatin + Rosuvastatin 
Washout 
Study Schema - Sequence BA 
-1 
1 
5 6 7 8 
11 
Screening 
-
• 
6. • 
I 
CONFIDENTIAL 
Clinic Confinement 
Intensive PK sampling 
Filgotinib 
Atorvastati n 
Pravastatin + Rosuvastatin 
Washout 
Page8 
6. 
• 
18 
20 
• e Discharge 
Follow-up 
23 
27 (±2) 
Follow-up 
23 Febrna1y 2021 


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 9
23 February 2021
Pharmacokinetic Assessments
Plasma Pharmacokinetic Collection
Plasma concentrations of ATV, 2-OH-ATV, PRA, and ROS will be determined and PK 
parameters will be evaluated. Plasma concentrations of filgotinib and its metabolite (GS-829845) 
may be analyzed. Intensive PK sampling will occur relative to dosing of study drug at the 
following time points. Details regarding study assessment can be found in Appendix 1 and 
Appendix 2.
Sequence AB:

Days 1 and 12: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 24, 36, 
and 48 hours postdose

Days 3 and 14: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 48, and 
72 hours postdose
Sequence BA:

Days 6 and 18: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 16, 24, 36, 
and 48 hours postdose

Days 8 and 20: 0 (predose, ≤ 5 minutes), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 48, and 
72 hours postdose
Genomic Sample Collection
A mandatory blood sample will be collected from all subjects who have provided consent to 
participate in this study. This sample will be collected for the extraction of DNA for genomic 
testing and genotyping to identify polymorphisms of drug transporters (eg, OATP1B1). This 
sample should be collected on Day 1, before administration of the first dose of study drug, but 
may be collected at any time during the study, if necessary.
Safety Assessments
Safety will be evaluated throughout the study. Details regarding study assessments can be found 
in Appendix 1 and Appendix 2.
1.4.
Sample Size and Power
With 26 evaluable subjects (13 in each sequence), the estimated two-sided 90% CI of the GLSM 
ratio of test versus reference treatments, with regards to AUCinf, AUClast, and Cmax, will be within 
[70%, 143%] with ≥ 85% probability, if the true GLSM ratio is 1.0. This is assuming a standard 
deviation (SD) of differences of no more than 0.569 on a natural logarithm scale, supported by 
PK data from Study GS-US-402-2102. With 4 subjects for overage, a total sample size of 30 
subjects will be required.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 10
23 February 2021
2.
TYPE OF PLANNED ANALYSIS
2.1.
Data Monitoring Committee Analyses
This study does not have a data monitoring committee (DMC). Therefore, no analyses will be 
conducted for the DMC.
2.2.
Interim Analysis
No interim analysis is planned.
2.3.
Final Analysis
After all subjects have completed the study, outstanding data queries have been resolved or 
adjudicated as unresolvable, and the data have been cleaned and finalized, the final analysis of 
the data will be performed.
2.4.
Changes from Protocol-Specified Analysis
No changes from protocol-specified analyses are planned.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 11
23 February 2021
3.
GENERAL CONSIDERATIONS FOR DATA ANALYSES
Analysis results will be presented using descriptive statistics. For categorical variables, the 
number and percentage of subjects in each category will be presented; for continuous variables, 
the number of subjects (n), mean, standard deviation (SD) or standard error (SE), median, first 
quartile (Q1), third quartile (Q3), minimum, and maximum will be presented.
By-subject listings will be presented for all subjects in the All Randomized Analysis Set and 
sorted by subject identification (ID) number in ascending order, visit date, and time 
(if applicable), unless otherwise specified. Data collected on log forms, such as AEs, will be 
presented in chronological order within subject. The treatment group and treatment sequence to 
which subjects were initially assigned will be used in the listings.
3.1.
Analysis Sets
Analysis sets define the subjects to be included in an analysis. Analysis sets and their definitions 
are provided in this section. The analysis set will be identified and included as a subtitle of each 
table, figure, and listing.
For each analysis set, the number and percentage of subjects eligible for inclusion will be 
provided in the disposition table as detailed in Section 4. A listing of reasons for exclusion from 
analysis sets will be provided by subject.
3.1.1.
All Randomized Analysis Set
The All Randomized Analysis Set includes all subjects randomized into the study after screening. 
This is the primary analysis set for safety listings.
3.1.2.
Safety Analysis Set
The Safety Analysis Set will include all randomized subjects who received at least 1 dose of 
study drug. Subjects who received treatment other than that to which they were assigned will be 
analyzed according to the treatment received. This is the primary analysis set for safety analyses.
3.1.3.
Pharmacokinetic Analysis Set
The PK Analysis Set will include all randomized subjects who received at least 1 dose of study 
drug and had at least 1 non-missing PK concentration datum reported by PK laboratory for each 
respective analyte. This is the primary analysis set for all PK analyses.
3.2.
Missing Data and Outliers
3.2.1.
Missing Data
In general, missing data will not be imputed unless methods for handling missing data are 
specified.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 12
23 February 2021
The handling of missing or incomplete dates for AE onset is described in Section 7.1.6.2.
3.2.2.
Outliers
Outliers of non-PK data will be identified during the data management and data analysis process, 
but no sensitivity analyses will be conducted. All data will be included in the data analysis.
3.3.
Data Handling Conventions and Transformations
In general, age (in years) on the date of the first dose of study drug will be used for analyses and 
presentation in listings. If an enrolled subject was not dosed with any study drug, the enrollment 
date will be used instead of the first dosing date of study drug. If only the birth year is collected 
on the CRF, “01 July” will be used for the unknown birth day and month for the purpose of age 
calculation. If only birth year and month are collected, “01” will be used for the unknown 
birthday.
Non-PK Data that are continuous in nature but are less than the lower limit of quantitation 
(LLOQ) or above the upper limit of quantitation (ULOQ) will be imputed as follows:

A value that is 1 unit less than the LLOQ will be used to calculate descriptive statistics if the 
datum is reported in the form of “ x” (where x is considered the LLOQ). For example, if the 
values are reported as < 50 and < 5.0, values of 49 and 4.9, respectively, will be used to 
calculate summary statistics. An exception to this rule is any value reported as 
< 1 or <0.1, etc. For values reported as < 1 or < 0.1, a value of 0.9 or 0.09, respectively, will 
be used to calculate summary statistics.

A value that is 1 unit above the LLOQ will be used to calculate descriptive statistics if the 
datum is reported in the form of “> x” (where x is considered the LLOQ). Values with 
decimal points will follow the same logic as the bullet point above.

The LLOQ will be used to calculate descriptive statistics if the datum is reported in the form 
of “≤ x” or “≥ x” (where x is considered the LLOQ).
If methods based on the assumption that the data are normally distributed are not adequate, 
analyses may be performed on transformed data or nonparametric analysis methods may be used, 
as appropriate.
Natural logarithmic transformation will be used for plasma concentrations and analysis of PK 
parameters. Plasma concentration values that are below the limit of quantitation (BLQ) will be 
presented as “BLQ” in the concentration data listing. Values that are BLQ will be treated as 0 at 
predose time points, and one-half the value of the lower limit of quantitation (LLOQ) at postdose 
time points for determination of summary and order statistics.
The following conventions will be used for the presentation of summary and order statistics:


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 13
23 February 2021

If at least 1 subject has a concentration value of BLQ for the time point, the minimum value 
will be displayed as “BLQ.”

If more than 25% of the subjects have a concentration data value of BLQ for given time 
point, the minimum and Q1 values will be displayed as “BLQ.”
If more than 50% of the subjects have a concentration data value of BLQ for a given time point, 
the minimum, Q1, and median values will be displayed as “BLQ.”

If more than 75% of the subjects have a concentration data value of BLQ for a given time 
point, the minimum, Q1, median, and Q3 values will be displayed as “BLQ.”

If all subjects have concentration data values of BLQ for a given time point, all order 
statistics (minimum, Q1, median, Q3, and maximum) and summary statistics will be 
displayed as “BLQ.”
PK parameters that are BLQ will be imputed as one-half the value of lower limit of quantitation 
(LLOQ) before log transformation or statistical model fitting.
3.4.
Visit Windows
3.4.1.
Definition of Predose, Postdose, Study day, and Treatment Day
Predose value is defined as the last available off-treatment value collected prior to the first dose 
of study drug.
Postdose value is defined as any value collected after the first dose of study drug and before the 
date of the last dose of study drug plus 30 days.
Study Day is the day relative to the date of the first dose of study drug administration.
Study Day will be calculated from the first dosing date of study drug and derived as follows:

For postdose study days: assessment date – first dosing date + 1

For days prior to the first dose: assessment date – first dosing date 
Therefore, Study Day 1 is the day of first dose of study drug administration.
Treatment Day is the day relative to the first dose of study drug administration in each period. 
Treatment Day 1 will be defined as the first dosing date of study drug in each period. Treatment 
Day will only be used in PK-related listings.
Treatment Day will be calculated from the date of first dose of study drug administration in each 
period and derived as follows:

For postdose treatment days: assessment date – first dosing date in each period + 1


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 14
23 February 2021

 For days prior to the first dose: assessment date – first dosing date in each period.
3.4.2.
Analysis Window
The nominal visit as recorded on the CRF will be used when data are summarized by visit. Any 
data relating to unscheduled visits will not be assigned to a particular visit or time point and in 
general will not be included in summaries but will be listed in the listings. However, the 
following exceptions will be made:

An unscheduled visit prior to the first dose of study drug may be included in the calculation 
of predose value, if applicable.

For subjects who prematurely discontinue from the study, ET data will be summarized as a 
separate visit, labeled ‘Early Termination Visit.’

For laboratory abnormalities, all postdose values (including scheduled and unscheduled 
visits) will be used to assess the maximum toxicity.

For vitals assessments, all postdose values (including scheduled and unscheduled visits) will 
be used to assess maximum postdose and maximum postdose change.
3.4.3.
Selection of Data in the Event of Multiple Records on the Same Day
Depending on the statistical analysis method, single values may be required for each day. For 
example, change from predose by visit usually requires a single value.
If multiple valid, non-missing numeric observations exist on a day, records will be chosen based 
on the following rules if a single value is needed:

For predose, the last available record on or prior to the date and time of the first dose of study 
drug will be selected. If there are multiple records with the same time or no time recorded on 
the same day, average (arithmetic or geometric mean, as appropriate) will be used for the 
predose value.

For postdose values:
The record closest to the nominal day for that visit will be selected.
If there are 2 records that are equidistant from the nominal day, the later record will be 
selected.
If there is more than 1 record on the selected day, the average will be taken, unless 
otherwise specified.
If multiple, valid, non-missing categorical observations exist on a day, records will be 
chosen based on the following rules if a single value is needed:


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 15
23 February 2021

For predose, the last available record on or prior to the date and time of the first dose of study 
drug will be selected. If there are multiple records with the same time or no time recorded on 
the same day, the value with the lowest severity will be selected (e.g., normal will be selected 
over abnormal for safety ECG findings).

For postdose values, if there are multiple records with the same time or no time recorded on 
the same day, the most conservative value within the window will be selected (e.g., abnormal 
will be selected over normal for safety findings).


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 16
23 February 2021
4.
SUBJECT DISPOSITION
4.1.
Subject Enrollment and Disposition
A summary of subject enrollment (randomization) and disposition will be provided by treatment 
sequence and overall. This summary will present the number of subjects randomized, and the 
number and percentage of subjects in each of the categories listed below. For the Safety Analysis 
Set category, the denominator for the percentage calculation will be the total number of subjects 
randomized for each column using All Randomized Analysis Set. For all other categories, the 
denominator for the percentage calculation will be the total number of subjects in the Safety 
Analysis Set for each column.

Safety Analysis Set

PK Analysis Set for each analyte

Completed study drug

Did not complete study drug with reason for premature discontinuation of study drug

Completed the study

Did not complete the study with reason for premature discontinuation of study
In addition, the total number of subjects who were enrolled and the number of subjects in each of 
the disposition categories listed above will be displayed in a flowchart.
The following by-subject listings will be provided by subject ID number in ascending order to 
support the above summary tables:

Reasons for premature discontinuation of study drug or study
A by-subject listing of subject disposition including treatment sequence, date of the first dose of 
study drug, date of the last dose of study drug(s) (study days), study drug completion status, 
reason for study drug discontinuation, study completion status, reason for study discontinuation, 
and PK set status (indicating whether or not a subject is included in a PK analysis set) will be 
provided by subject ID number in ascending order.
4.2.
Extent of Exposure
A subject’s extent of exposure to study drug data will be generated from the study drug 
administration page in the eCRF. Exposure data will be listed.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 17
23 February 2021
4.3.
Protocol Deviations
A by-subject listing will be provided for those subjects who violated at least 1 inclusion or 
exclusion criterion, regardless of whether they were exempted or not by the sponsor. The listing 
will present the entry criterion (or criteria if more than 1 violation) that subjects did not meet and 
related comments, if collected.
Protocol deviations occurring after subjects entered the study are documented during routine 
monitoring. Any deviations identified will be evaluated to determine if it justifies excluding the 
subjects from any analysis sets.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 18
23 February 2021
5.
BASELINE CHARACTERISTICS
5.1.
Demographics
Subject demographic variables (ie, age, sex, race, and ethnicity) will be summarized by treatment 
sequence and overall using descriptive statistics for continuous variables and using number and 
percentage of subjects for categorical variables. The summary of demographic data will be 
provided for the Safety Analysis Set.
A by-subject demographic listing, including the informed consent date, will be provided by 
subject ID number in ascending order.
5.2.
Other Baseline Characteristics
Other baseline characteristics include creatine clearance (as measured by Cockcroft-Gault 
equation) {Cockcroft 1976}), height, BMI, body weight, and blood tests. These baseline 
characteristics will be summarized by treatment sequence and overall using descriptive statistics 
for continuous variables and using number and percentage of subjects for categorical variables. 
The summary of baseline characteristics will be provided for the Safety Analysis Set. No formal 
statistical testing is planned.
A by-subject listing of other baseline characteristics will be provided by subject ID number in 
ascending order.
5.3.
Medical History
General medical history data will be collected at screening and listed only. General medical 
history data will not be coded.
A by-subject listing of general medical history will be provided by subject ID number in 
ascending order. The listing will include relevant medical condition or procedure reported term, 
onset date, ongoing status, and resolution date (if applicable).


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 19
23 February 2021
6.
EFFICACY ANALYSES
Efficacy will not be evaluated in the study.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 20
23 February 2021
7.
SAFETY ANALYSES
7.1.
Adverse Events and Deaths
7.1.1.
Adverse Event Dictionary
Clinical and laboratory adverse events (AEs) will be coded using Medical Dictionary for 
Regulatory Activities (MedDRA) 23.1. System organ class (SOC), high-level group term 
(HLGT), high-level term (HLT), preferred term (PT), and lower-level term (LLT) will be 
provided in the AE dataset.
7.1.2.
Adverse Event Severity
Adverse events are graded by the investigator using the Common Terminology Criteria for 
Adverse Events (CTCAE) Toxicity Grading Scale, Version 5. The severity grade of events for 
which the investigator did not record severity will be categorized as “missing” for tabular 
summaries and data listings. The missing category will be presented last in the summary 
presentation.
7.1.3.
Relationship of Adverse Events to Study Drug
Study drug related AEs are those for which the investigator selected “Related” on the AE CRF to 
the question of “Related to Study Treatment.” Relatedness will always default to the 
investigator’s choice, not that of the medical monitor. Events for which the investigator did not 
record relationship to study drug will be considered related to study drug for summary purposes. 
However, by-subject data listings will show the relationship as missing from that captured on the 
CRF.
7.1.4.
Relationship of Adverse Events to Study Procedure
Study procedure related AEs are those for which the investigator selected “Yes” on the AE CRF 
to the question of “Related to Study Procedures”. Relatedness will always default to the 
investigator’s choice, not that of the medical monitor. Events for which the investigator did not 
record relationships to study procedure be considered related to study procedure for summary 
purposes. However, by-subject data listings will show the relationship as missing from that 
captured on the CRF.
7.1.5.
Serious Adverse Events
Serious adverse events (SAEs) will be identified and captured as SAEs if the AEs met the 
definition of SAEs that were specified in the study protocol. Serious adverse events captured and 
stored in the clinical database will be reconciled with the SAE database from the Global Patient 
Safety Department before database finalization.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 21
23 February 2021
7.1.6.
Treatment-Emergent Adverse Events
7.1.6.1.
Definition of Treatment Emergent
Treatment-emergent adverse events (TEAEs) are defined as any AEs with an onset date on or 
after the study drug start date and no later than 30 days after permanent discontinuation of study 
drug. If the AE onset date is the same as the date of study drug start date, the AE onset time must 
be on or after the study drug start time. If the AE onset time is missing when the start dates are 
the same, the AE will be considered treatment emergent.
TEAEs with an onset date on/after previous treatment administration date and prior to the next 
treatment administration date will be attributed to the previous treatment.
7.1.6.2.
Incomplete Dates
If the onset date of the AE is incomplete and the AE stop date is not prior to the first dosing date 
of study drug, then the month and year (or year alone if month is not recorded) of onset 
determine whether an AE is treatment emergent. The event is considered treatment emergent if 
both of the following 2 criteria are met:

The AE onset is the same as or after the month and year (or year) of the date of first dose of 
study drug, and

The AE onset date is the same as or before the month and year (or year) of the date 
corresponding to 30 days after the date of the last dose of study drug
An AE with completely missing onset and stop dates, or with the onset date missing and a stop 
date later than the date of the first dose of study drug, will be considered to be treatment 
emergent. In addition, an AE with the onset date missing and incomplete stop date with the same 
or later month and year (or year alone if month is not recorded) as the first dosing date of study 
drug will be considered treatment emergent.
7.1.7.
Summaries of Adverse Events and Deaths
The number and percentage of subjects who experienced at least 1 TEAE will be provided and 
summarized by SOC and PT, and by treatment sequence with treatments listed thereunder based 
on the Safety Analysis Set as follows:

All TEAEs

All TEAEs related to study drug

All TEAEs related to study procedures

All TEAEs by severity 


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 22
23 February 2021

TEAEs of Grade 3 or higher

All TEAEs related to study drug by severity

All SAEs

All SAEs related to study drug

All TEAEs leading to premature discontinuation of study drug

Death
There will be two ways to summarize AEs:
1) Two treatment sequences will be combined. And the same treatment (FIL, ATV, etc.) from 
different treatment sequence will be pooled together.
2) Two treatment sequences will be summarized separately. 
A brief, high-level summary of AEs described above will be provided by the number and 
percentage of subjects who experienced the above AEs and by treatment group and overall total. 
All deaths observed in the study will also be included in this summary.
Multiple events will be counted only once per subject per treatment in each summary. An AE 
that starts in one treatment period and continues into the following treatment period(s) will be 
counted only in the period in which the AE began. Adverse events will be summarized and listed 
first in alphabetic order of SOC and then by PT in descending order of total frequency within 
each SOC, and the alphabetic order of PT will be applied within the same frequency. For 
summaries by grade, the most severe grade will be used for those AEs that occurred more than 
once in an individual subject per treatment during the study.
In addition to the above summary tables, all TEAEs and SAEs will be summarized by PT only, in 
descending order of total frequency and the alphabetic order within the same frequency.
In addition, data listings will be provided by subject for the following:

All AEs (indicating whether the event is treatment emergent)

SAEs

Deaths

AEs leading to premature discontinuation of study drug
7.1.8.
Additional Analysis of Adverse Events
No additional analysis of adverse events is planned.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 23
23 February 2021
7.2.
Laboratory Evaluations
Laboratory data collected during the study will be analyzed and summarized using both 
quantitative and qualitative methods. Summaries of laboratory data will be provided for the 
Safety Analysis Set and will include data collected up to the last dose of study drug plus 30 days 
for subjects who have permanently discontinued study drug. The analysis will be based on values 
reported in conventional units. When values are BLQ, the imputed value will be used for the 
purpose of calculating summary statistics. If a lab value is reported using a non-numeric qualifier 
(eg, less than (<) a certain value, or greater than (>) a certain value), the given numeric value will 
be used in the summarization and will be listed. Both of them will be listed as such.
The Incidence of treatment-emergent graded laboratory abnormalities will be summarized by 
treatment sequence with treatments listed thereunder. 
A by-subject listing for laboratory test results will be provided by subject ID number and time 
point in chronological order for hematology, serum chemistry (fasting) and urinalysis separately. 
Values falling outside of the relevant reference range and/or having a severity grade of 1 or 
higher on the Gilead Grading Scale for Severity of Adverse Events and Laboratory 
Abnormalities and treatment emergent graded laboratory abnormalities will be flagged in the 
data listings, as appropriate. 
Listings by subjects for Serum pregnancy test (females of childbearing potential only), 
Hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus type 1 testing 
(HIV-1), Follicle Stimulating Hormone (FSH), Thyroid stimulating hormone testing (screening 
only), and Urine drug and alcohol assessments at screening will also be provided. 
Separate by-subject listing of treatment-emergent laboratory abnormalities and 
treatment-emergent grade 3 or higher laboratory abnormalities will be provided by subject 
ID number and visit in chronological order. These listing will include all test results that were 
collected throughout the study for the laboratory test(s) of interest, with all applicable severity 
grades displayed.
No inferential statistics will be generated.
7.2.1.
Summaries of Numeric Laboratory Results
Descriptive statistics will be provided by treatment sequence for all laboratory test specified in 
the study protocol as follows:

Predose values

Values at each postdose scheduled time point

Change from predose at each postdose scheduled time point


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 24
23 February 2021
Predose and postdose values will be defined as described in Section 3.4. Change from predose to 
a postdose visit will be defined as the visit value minus the predose value. The mean, median, 
Q1, Q3, minimum, and maximum values will be displayed to the reported number of digits; SD 
values will be displayed to the reported number of digits plus 1.
In the case of multiple values in an analysis window, data will be selected for analysis as 
described in Section 3.4.2.
7.2.2.
Graded Laboratory Values
The CTCAE Version 5.0 will be used to assign toxicity grades (0 to 4) to laboratory results for 
analysis. Grade 0 includes all values that do not meet the criteria for an abnormality of at least 
Grade 1. For laboratory tests with criteria for both increased and decreased levels, analyses for 
each direction (ie, increased, decreased) will be presented separately. 
7.2.2.1.
Treatment-Emergent Laboratory Abnormalities
Treatment-emergent laboratory abnormalities are defined as values that increase at least 
1 toxicity grade from predose at any postdose time point, up to and including the date of last 
dose of study drug plus 30 days for subjects who permanently discontinued study drug. If the 
relevant predose laboratory value is missing, any abnormality of at least Grade 1 observed within 
the time frame specified above will be considered treatment emergent.
7.2.2.2.
Summaries of Treatment-emergent Laboratory Abnormalities
The following summaries (number and percentage of subjects) for treatment-emergent laboratory 
abnormalities will be provided by lab test and by treatment sequence with treatments under the 
treatment sequence; subjects will be categorized according to the most severe postdose 
abnormality grade for a given lab test within a treatment:

Treatment-emergent graded laboratory abnormalities

Treatment-emergent grade 3 or higher laboratory abnormalities
There will be two ways to summarize treatment-emergent laboratory abnormalities:
3) Two treatment sequences will be combined. And the same treatment (FIL, ATV, etc.) from 
different treatment sequence will be pooled together.
4) Two treatment sequences will be summarized separately. 
For all summaries of laboratory abnormalities, the denominator is the number of subjects with 
nonmissing postdose values up to 30 days after last dosing date.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 25
23 February 2021
7.2.3.
Liver-Related Laboratory Evaluations
Liver-related abnormalities after initial study drug dosing will be examined and summarized 
using the number and percentage of subjects who were reported to have the following laboratory 
test values for postdose measurements:

Aspartate aminotransferase (AST): (a) > 3 times of the upper limit of reference range (ULN); 
(b) > 5  ULN; (c) > 10  ULN; (d) > 20  ULN

Alanine aminotransferase (ALT): (a) > 3  ULN; (b) > 5  ULN; (c) > 10  ULN; 
(d) > 20  ULN

AST or ALT: (a) > 3  ULN; (b) > 5  ULN; (c) > 10  ULN; (d) > 20  ULN

Total bilirubin: > 2  ULN

Alkaline phosphatase (ALP) > 1.5  ULN

AST or ALT > 3  ULN and total bilirubin: (a) > 1.5  ULN; (b) > 2  ULN
The summary will be provided by treatment sequence with treatments listed thereunder. 
There will be two ways to summarize liver-related laboratory abnormalities:
5) Two treatment sequences will be combined. And the same treatment (FIL, ATV, etc.) from 
different treatment sequence will be pooled together.
6) Two treatment sequences will be summarized separately. 
The summary will include data from all postdose visits up to 30 days after the last dose of study 
drug. For individual laboratory tests, subjects will be counted once based on the most severe 
postdose values. For both the composite endpoint of AST or ALT and total bilirubin, subjects 
will be counted once when the criteria are met at the same postdose visit date. The denominator 
is the number of subjects in the Safety Analysis Set who have nonmissing postdose values of all 
relevant tests at the same postdose visit date. A listing of subjects who met at least 1 of the above 
criteria will be provided.
7.3.
Body Weight, Height, BMI, and Vital Signs
Descriptive statistics will be provided by treatment sequence for body weight, BMI, and vital 
signs as follows:

Predose value

Values at each postdose at scheduled time point

Change from predose at each postdose scheduled time point


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 26
23 February 2021
In addition, descriptive statistics will be provided by treatment sequence for height at baseline 
only.
Predose and postdose values will be defined as described in Section 3.4. Change from predose to 
a postdose visit will be defined as the postdose value minus the predose value.
In the case of multiple values in an analysis window, data will be selected for analysis as 
described in Section 3.4.2. No inferential statistics will be generated.
A by-subject listing of vital signs will be provided by subject ID number and time point in 
chronological order. Body weight, height, and BMI will be included in the vital signs listing, if 
space permits, otherwise they will be provided separately.
7.4.
Prior and Concomitant Medications
Medications collected at screening, admission (Day -1) and during the study will be coded using 
the BMAR20 version of the World Health Organization (WHO) Drug dictionary.
A summary of prior and concomitant medications will not be provided.
All prior and concomitant medications (other than per-protocol study drugs) will be provided in a 
by-subject listing sorted by subject ID number and administration date in chronological order.
7.5.
Electrocardiogram Results
Electrocardiogram (ECG) data will not be presented in the CSR since ECGs were not assessed in 
this study other than as part of the screening process for potential new subjects.
A by-subject listing for ECG assessment results will be provided.
7.6.
Other Safety Measures
By-subject listings for creatine clearance test results and physical examination findings during 
the study will be provided by subject ID number. 
Although not necessarily related to safety, a by-subject listing of all comments received during 
the study on the comments form will be provided by subject ID number, and form for which the 
comment applies.
7.7.
Changes From Protocol-Specified Safety Analyses
If any of below events related to COVID-19 occurs, a by-subject listing may be provided by 
subject identification (ID) number in ascending order to show:

Reasons for premature study drug or study discontinuation due to COVID-19

Important protocol deviations related to COVID-19

AEs related to COVID-19


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 27
23 February 2021
Premature study drug or study discontinuation due to COVID-19 is identified either with reason 
of AE, and AE is COVID-19 related, or with reason of other than AE, and description contains 
key word “COVID”.
IPD related to COVID-19 is identified by searching description with key word “COVID”.
AE’s related to COVID-19. 
Vital sign will only be summarized by treatment sequence, not treatment. 
Electrocardiogram assessments will not be summarized by treatment or treatment sequence, as 
they will only be performed as part of the screening process.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 28
23 February 2021
8.
PHARMACOKINETIC EVALUATION/ANALYSIS
8.1.
Estimation of Pharmacokinetic Parameters
Pharmacokinetic parameters will be estimated using Phoenix WinNonlin® software using 
standard noncompartmental methods, with input values for dose level, dosing time, plasma 
concentration, and corresponding real-time values, based on drug dosing times whenever 
possible.
All predose sample times before time-zero will be converted to zero.
For area under the curve (AUC), samples below the limit of quantitation (BLQ) of the 
bioanalytical assays occurring prior to the achievement of the first quantifiable concentration will 
be assigned a concentration value of zero to prevent overestimation of the initial AUC. Samples 
that are BLQ at all other time points will be treated as missing data in WinNonlin. The nominal 
time point for a key event or dosing interval (τ) may be used to permit direct calculation of AUC 
over specific time intervals. The appropriateness of this approach will be assessed by the PK 
scientist on a profile-by-profile basis.
Pharmacokinetic parameters such as AUCinf, λz and t1/2 are dependent on an accurate estimation 
of the terminal elimination phase of drug. The appropriateness of calculating these parameters 
will be evaluated upon inspection of PK data on a profile-by-profile basis by the PK scientist.
8.1.1.
Pharmacokinetic Parameters
Pharmacokinetic parameters will be generated for all subjects for whom parameters can be 
derived. The analytes presented in Table 8-1 will be evaluated if data are available.
Table 8-1.
Study Treatments and Associated Analytes
Sequence
Treatment
Analyte
ATV
2-OH-ATV
PRA
AB
Treatment A:
ATV
PRA/ROS
Treatment B:
FIL + ATV
FIL + PRA/ROS
ROS
ATV
2-OH-ATV
PRA
BA
Treatment B:
FIL + ATV
FIL + PRA/ROS
Treatment A:
ATV
PRA/ROS
ROS


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 29
23 February 2021
The analytes and parameters presented in Table 8-2 will be used to evaluate the PK objectives of 
the study. The primary PK parameters are AUClast, AUCinf, and Cmax of ATV, 2-OH-ATV, PRA 
and ROS. Other PK parameters will be presented as applicable. The PK parameters to be 
estimated in this study are listed and defined in the Pharmacokinetic Abbreviations section.
Table 8-2.
Pharmacokinetic Parameters for Each Analyte
Matrix
Analyte
Parameters
ATV
2-OH-ATV
PRA
Plasma
ROS
AUClast , AUCinf , %AUCexp , Cmax , Clast , Tmax , Tlast , λz , CL/F, 
Vz /F and t1/2 , as applicable
In addition, molar ratio of metabolite to parent exposure (AUClast, AUCinf, and Cmax) will be 
calculated for individual subjects and summarized by treatment group of ATV alone and ATV + 
FIL. 

The 2-OH-ATV to ATV ratio for AUClast will be calculated by dividing the AUClast (in 
h*nmol/L) of 2-OH-ATV by the AUClast (in h*nmol/L) of ATV. 

The 2-OH-ATV to ATV ratio for AUCinf will be calculated by dividing the AUCinf (in 
h*nmol/L) of 2-OH-ATV by the AUCinf ((in h*nmol/L) of ATV. 

The 2-OH-ATV to ATV ratio for Cmax will be calculated by dividing the Cmax (in nmol/L) 
of 2-OH-ATV by the Cmax (in nmol/L) of ATV.
8.1.2.
Statistical Analysis Method
8.1.2.1.
General Consideration
Individual subject concentration data and individual subject PK parameters for ATV, 2-OH-
ATV, PRA and ROS will be listed and summarized using descriptive statistics by treatment. 
Summary statistics (numbers of subjects, mean, SD, coefficient of variation [%CV], median, 
minimum, maximum, Q1, and Q3) will be presented for both individual subject concentration 
data by time point and individual subject PK parameters by treatment. Moreover, the geometric 
mean, 95% confidence interval (CI), and the mean and SD of the natural log-transformed values 
will be presented for individual subject PK parameter data.
Individual concentration data listings and summaries will include all subjects with concentration 
data. The sample size for each time point will be based on the number of subjects with 
nonmissing concentration data at that time point. The number of subjects with concentration 
BLQ will be presented for each time point. For summary statistics, BLQ values will be treated as 
zero at predose and one-half of the lower limit of quantitation (LLOQ) for postdose time points.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 30
23 February 2021
Individual PK parameter data listings and summaries will include all subjects for whom PK 
parameters can be derived. The sample size for each PK parameter will be based on the number 
of subjects with nonmissing data for that PK parameter.
The following tables will be provided for ATV, 2-OH-ATV, PRA and ROS by treatment:

Individual subject concentration data and summary statistics

Individual subject plasma PK parameters and summary statistics
The following figures will be provided for ATV versus ATV + FIL, and PRA/ROS versus 
PRA/ROS + FIL by treatment:

Individual subjects concentration data versus time (on linear and semilogarithmic scales)

Mean (± SD) concentration data versus time (on linear and semilogarithmic scales)

 Median (Q1, Q3) concentration data versus time (on linear and semilogarithmic scales) 
Individual, mean, and median postdose concentration values that are ≤ LLOQ will not be 
displayed in the figures and remaining point connected. 
The following listings will be provided:

PK sampling details by subject, including procedures, differences in scheduled and actual 
draw times, and sample age

Individual data on determination of plasma half-life and corresponding regression correlation 
coefficient by analyte.
8.1.2.2.
Statistical Methodology
8.1.2.2.1.
8.1.3.2.1 Analysis of Drug-Drug Interaction
An analysis of variance (ANOVA) using a mixed-effects model with treatment, period, and 
sequence as fixed effects and subject as a random effect will be fitted to the natural logarithmic 
transformation of PK parameters (AUClast, AUCinf, Cmax) for ATV versus ATV + FIL, and 
PRA/ROS versus PRA/ROS+FIL. The same model will be fitted to the natural logarithmic 
transformation of molar ratio of metabolite to parent exposure (2-OH-ATV to ATV) of PK 
parameters (AUClast, AUCinf, and Cmax) for ATV versus ATV + FIL. Additional analyses may be 
performed if useful and appropriate. Two-sided 90% CIs will be calculated for the ratios of 
geometric least-squares means (GLSMs) of primary PK parameters between test (Treatment B) 
versus reference (Treatment A) treatments.
Lack of PK interaction between the test and reference treatments will be concluded if the 
90% CIs for the GLSM ratios are contained within the 70% - 143% range for ATV, 2-OH-ATV, 
PRA, and ROS AUC and Cmax. 


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 31
23 February 2021
Treatment comparisons of interest are shown in Table 8-3.
Table 8-3.
Statistical Comparisons for Pharmacokinetic Analyses
Comparison (mean [%CV])
Analyte
Parameter
Test
Reference
(% GLSM ratio and 90% CI)
ATV
2-OH-ATV
ATV+FIL
ATV
PRA
ROS
AUClast 
AUCinf
Cmax
PRA/ROS+FIL
PRA/ROS
Molar ratio of 
2-OH-ATV to 
ATV
AUClast / AUClast
AUCinf / AUCinf
Cmax  / Cmax
 ATV+FIL
      ATV
Lack of effect boundary:
70% - 143%
The statistical model will include treatment period and treatment sequence as a fixed effect and 
subject as a random effect. The following SAS PROC MIXED code will provide the treatment 
comparison analysis and the 90% CI calculations for natural log-transformed PK parameters.
proc mixed;
where param=‘AUClast’; 
class treat period sequence subjid; 
model lnest = treat period sequence / ddfm=kr; 
random subjid;
lsmeans treat / diff cl alpha = 0.1;
estimate ‘Test versus Reference’ treat -1 1 / cl alpha = 0.10;
ods output Estimates = LS_Diffs LSMeans = LS_Means CovParms MSE;  
 run;
The ESTIMATE statement will be used to produce the point estimate and the corresponding 
90% CI of the difference in PK parameters of interest on a logarithmic scale. The 
test-to-reference ratio and associated 90% CI will be calculated by taking the exponential of the 
point estimate and the corresponding lower and upper limits, which is consistent with the 
two 1-sided tests approach {U.S. Department of Health and Human Services Food and Drug 
Administration Center for Drug Evaluation and Research (CDER) 2001, U.S. Department of 
Health and Human Services Food and Drug Administration Center for Drug Evaluation and 
Research (CDER) 2003}.
8.1.3.
Sensitivity Analysis
Sensitivity analysis may be conducted for the key PK analyses if the PK scientist identifies PK 
data as questionable. The sensitivity analysis will exclude specific data from analyses, if 
appropriate. If a sensitivity analysis is deemed necessary, a listing of the PK parameter(s) data 
being excluded, with associated reason(s) provided by the PK scientist, will be generated.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 32
23 February 2021
8.1.4.
Changes From Protocol-Specified PK Analyses
Rather than 26 subjects (13 in each sequence), as specified in the protocol, 25 evaluable subjects 
(12 in one sequence and 13 in another sequence) was randomized and completed the study. The 
probability of the estimated two-sided 90% CI of the GLSM ratio of test versus reference 
treatments, with regards to AUCinf, AUClast, and Cmax, will be within [70%, 143%] changed from 
≥ 85% to ≥ 83%.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 33
23 February 2021
9.
REFERENCES
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 
1976;16:31-41.
U.S. Department of Health and Human Services Food and Drug Administration Center for Drug 
Evaluation and Research (CDER). Guidance for Industry. Statistical Approaches 
to Establishing Bioequivalence.  January, 2001.
U.S. Department of Health and Human Services Food and Drug Administration Center for Drug 
Evaluation and Research (CDER). Guidance for Industry. Bioavailability and 
Bioequivalence Studies for Orally Administered Drug Products - General 
Considerations (Revision 1).  March, 2003.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 34
23 February 2021
10.
SOFTWARE
SAS® Software Version 9.4. SAS Institute Inc., Cary, NC, USA.
Phoenix WinNonlin® 8.2. Pharsight Corporation, Princeton, NJ, USA. 
nQuery Version 8.5.2.0. Statistical Solutions, Cork, Ireland.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 35
23 February 2021
11.
SAP REVISION
Revision Date
(DD MMM YYYY)
Section
Summary of Revision
Reason for Revision


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 36
17 February 2021
12.
APPENDICES
Appendix 1.
Schedule of Assessments (Sequence AB)
Study 
Procedure
Screeninga
Admission
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
Day 13
Day 14
Day 15
Day 16
Discharge
Day 17b
Follow-Upc
Day  24 ± 2
ETd
Written 
Informed 
Consent
X
Medical History 
X
Complete 
Physical 
Examination
X
X
X
X
X
Symptom-
Driven Physical 
Examinatione
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Height 
X
Weight 
X
X
X
X
X
X
Vital Signsf
X
X
X
X
X
X
X
X
X
X
X
X
HIV-1, HBV, 
and HCV 
Testingg
X
Hematologyg
X
X
X
X
X
X
X
X
X
X
X
X
Chemistryg
X
X
X
X
X
X
X
X
X
X
X
X
Creatine 
phosphokinase 
(CPK)
X
X
X
X
X
X
X
X
X
X
X
X
Calculated 
Creatinine 
Clearance
X
X
X
X
X
X


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 37
17 February 2021
Study 
Procedure
Screeninga
Admission
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
Day 13
Day 14
Day 15
Day 16
Discharge
Day 17b
Follow-Upc
Day  24 ± 2
ETd
Urinalysisg
X
X
X
X
X
X
X
X
X
X
X
X
Serum 
Pregnancy 
Testg,h
X
X
X
X
Urine Pregnancy 
Test h
X
X
Follicle-
Stimulating 
Hormone
(FSH)
g,h
X
Thyroid 
Stimulating 
Hormone 
(TSH)gh
X
Urine Drug 
and Alcohol 
Screeng
X
X
12-Lead ECG
X
COVID-19 
RT-PCR
X
X
Randomizatio
n/ Enrollmenti
X
Study Drug 
Administratio
nj
X
X
X
X
X
X
X
X
X
X
X
X
X
Intensive 
Plasma PKk
X
X
X
X
Genotype 
Testingl
X


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 38
17 February 2021
Study 
Procedure
Screeninga
Admission
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
Day 13
Day 14
Day 15
Day 16
Discharge
Day 17b
Follow-Upc
Day  24 ± 2
ETd
Review Study 
Restrictions
X
X
X
X
Clinic 
Confinement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Review AEs 
& 
Concomitant 
Medicationsm
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
AE = adverse event; ECG = electrocardiogram; COVID-19 RT-PCR = a real-time reverse transcription polymerase chain reaction (rTT-PCR) test for the qualitative detection of 
nucleic acid from SARS-CoV-2
eCRF = electronic case report form; ET = early termination; HBV = hepatitis B virus; HCV = hepatitis C virus; HIV-1= human immunodeficiency virus type 1 and type 2;
PE = physical examination; PG = pharmacogenomic; PK = pharmacokinetics
a.
Prospective subject should be screened no more than 28 days prior to administration of the first dose of study drug.
b.
Subjects will be discharged from the clinic on Day 17 (Sequence AB) following all assessments.
c.
7 (± 2) days after the last administration of study drug, all subjects will be contacted via telephone to review and document AEs and concomitant medications
d.
Early termination (ET) assessments will be performed within 72 hours of prematurely discontinuing from the study.
e.
Symptom-driven PEs will be performed during confinement as needed, based on reported signs and symptoms.
f.
Vital signs include blood pressure, heart rate, respiration rate, and body temperature.
g.
See Protocol Section 6.6.5 for specifics.
h.
Females of childbearing potential only.
i.
On Day −1, subjects will be randomized the evening to receive 1 of 2 treatment sequences starting on Day 1.
j.
See Protocol Section 5.4 for specifics.
k.
Intensive PK sampling will occur relative to the morning dosing of study drug at the time points as outlined in Protocol Section 6.5.1.
l.
Blood sample should be collected on Day 1, but may be collected at any time during the study, if necessary
m.
From the time of obtaining informed consent through the first administration of study drug, record all SAEs, as well as any nonserious AEs related to protocol-mandated 
procedures, on the AE eCRF. All other untoward medical occurrences observed during the screening period, including exacerbation or changes in medical history, are to be 
captured on the medical history eCRF. See Section 7, Adverse Events and Toxicity Management, for additional details.


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 39
17 February 2021
Appendix 2.
Schedule of Assessments (Sequence BA)
Study 
Procedure
Screeninga
Admission 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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge Day 23b
Follow-Upc 
Day 27 ± 2
ETd
Written 
Informed 
Consent
X
Medical 
History
X
Complete 
Physical 
Examination
X
X
X
X
X
Symptom- 
Driven 
Physical 
Examination
e
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Height
X
Weight
X
X
X
X
X
X
X
Vital Signs
f
X
X
X
X
X
X
X
X
X
X
X
X
X
HIV-1, HBV,
and HCV 
Testing
g
X
Hematology
g
X
X
X
X
X
X
X
X
X
X
X
X
X
Chemistry
g
X
X
X
X
X
X
X
X
X
X
X
X
X
Creatine 
phosphokinas
e (CPK)
X
X
X
X
X
X
X
X
X
X
X
X
X
Calculated 
Creatinine 
Clearance
X
X
X
X
X
X
X
Urinalysis
g
X
X
X
X
X
X
X
X
X
X
X
X
X
Urine 
Pregnancy 
Test
X
X


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 40
17 February 2021
Study 
Procedure
Screeninga
Admission 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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge Day 23b
Follow-Upc 
Day 27 ± 2
ETd
Follicle- 
Stimulating 
Hormone 
(FSH) 
g,h
X
Thyroid 
Stimulating 
Hormone 
(TSH)
gh
X
Serum 
Pregnancy 
Testg, h
X
X
X
X
X
Urine Drug 
and Alcohol 
Screen
g
X
X
12-Lead 
ECG
X
COVID-19 
RT-PCR
X
X
Randomizati
on
/Enrollment
i
X
Study Drug 
Administratio
n
j
X
X
X
X
X
X
X
X
X
X
X
X
X
Intensive 
Plasma PK
k
X
X
X
X
Genotype 
Testing
l
X
Review 
Study
Restrictions
X
X
X
X
Clinic 
Confinement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X


Filgotinib 
GS-US-417-5937
Statistical Analysis Plan
Version 1.0
CONFIDENTIAL
Page 41
17 February 2021
Study 
Procedure
Screeninga
Admission 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
Day 13
Day 14
Day 15
Day 16
Day 17
Day 18
Day 19
Day 20
Day 21
Day 22
Discharge Day 23b
Follow-Upc 
Day 27 ± 2
ETd
Review AEs 
& 
Concomitant 
Medications
m
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
AE = adverse event; ECG = electrocardiogram; COVID-19 RT-PCR=a real-time reverse transcription polymerase chain reaction (rTT-PCR) test for the qualitative detection of 
nucleic acid from SARS-CoV-2
eCRF = electronic case report form; ET = early termination; HBV = hepatitis B virus; HCV = hepatitis C virus; HIV-1 = human immunodeficiency virus type 1 and type 2; PE = 
physical examination; PG = pharmacogenomic; PK = pharmacokinetic(s); COVID-19 RT-PCR=a real-time reverse transcription polymerase chain reaction (rTT-PCR) test for the 
qualitative detection of nucleic acid from SARS-CoV-2
a.
Prospective subjects should be screened no more than 28 days prior to administration of the first dose of study drug.
b.
Subjects will be discharged from the clinic on Day 23 (Sequence BA) following all assessments.
c.
7 (± 2) days after the last administration of study drug, all subjects will be contacted via telephone to review and document AEs and concomitant medications.
d.
Early termination (ET) assessments will be performed within 72 hours of prematurely discontinuing from the study.
e.
Symptom-driven PEs will be performed during confinement as needed, based on reported signs and symptoms.
f.
Vital signs include blood pressure, heart rate, respiration rate, and body temperature.
g.
See Protocol Section 6.6.5 for specifics.
h.
Females of childbearing potential only.
i.
On Day −1, subjects will be randomized the evening to receive 1 of 2 treatment sequences starting on Day 1.
j.
See Protocol Section 5.4 for specifics.
k.
Intensive PK sampling will occur relative to the morning dosing of study drug at the time points as outlined in Protocol Section 6.5.1.
l.
Blood samples should be collected on Day 1, but may be collected at any time during the study, if necessary
m.
From the time of obtaining informed consent through the first administration of study drug, record all SAEs, as well as any nonserious AEs related to protocol-mandated 
procedures, on the AE eCRF. All other untoward medical occurrences observed during the screening period, including exacerbation or changes in medical history, are to be 
captured on the medical history eCRF. See Section 7, Adverse Events and Toxicity Management, for additional details.


GS-US-417-5937_SAP
ELECTRONIC SIGNATURES
Signed by
Meaning of Signature
Server Date
(dd-MMM-
yyyy hh:mm:ss)
Clinical Pharmacology
eSigned
25-Feb-2021
21:51:56
Project Team
Leader eSigned
25-Feb-2021
22:15:48
Biostatistics eSigned
26-Feb-2021
08:20:35
PPD
PPD
PPD