A Randomized, Double-Blind, Placebo-Controlled, Phase 2 Study to Evaluate the Safety and Efficacy of IW-1973 in Patients With Type 2 Diabetes With Albuminuria Treated With Renin-Angiotensin System Inhibitors
Phase: PHASE2
Conditions: Type 2 Diabetes Mellitus With Diabetic Nephropathy
Sponsor: Akebia Therapeutics



IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 3 of 106 
SYNOPSIS 
Sponsor: Ironwood Pharmaceuticals, Inc. 
Name of Finished Product: IW-1973 Tablets 
Name of Active Ingredient: IW-1973 
Study Title: 
A Randomized, Double-blind, Placebo-controlled, Phase 2 Study to Evaluate the Safety and 
Efficacy of IW-1973 in Patients with Type 2 Diabetes with Albuminuria Treated with Renin-
Angiotensin System Inhibitors  
Study Number: C1973-203 
Study Phase: 2 
Study Objectives 
Primary 
• To assess the safety and tolerability of oral IW-1973 when administered daily for 
approximately 12 weeks to adult patients with type 2 diabetes mellitus with albuminuria 
who are on a stable regimen of renin-angiotensin system inhibitors 
• To evaluate the effect of oral IW-1973 on renal function when administered daily for 
approximately 12 weeks to adult patients with type 2 diabetes mellitus with albuminuria 
who are on a stable regimen of renin-angiotensin system inhibitors 
Study Design 
This multicenter, randomized, double-blind, placebo-controlled, parallel-group study will 
evaluate 2 dose levels of IW-1973 compared with placebo.  
Study Population and Planned Number of Patients  
The study population will consist of adult patients with type 2 diabetes mellitus, albuminuria, 
and impaired renal function. Patients must have been taking antihyperglycemic medications for 
at least 12 weeks and with their regimen stable (ie, drug and dose) for at least 28 days before 
the Randomization Visit. Additionally, patients must have been on a stable regimen of an 
angiotensin-converting enzyme inhibitor (ACEi) or an angiotensin receptor blocker (ARB), for 
at least 28 days before the Randomization Visit. For details, see Eligibility Criteria. 
Approximately 150 patients (50 per arm) will be stratified by baseline estimated glomerular 
filtration rate (eGFR) (ie, eGFR 30 to 45, >45 to 60, and >60 to 75 mL/min/1.73 m2) and 
randomized 1:1:1 to daily 20 mg IW-1973, 40 mg IW-1973, or placebo. Patients who withdraw 
from the study after Randomization will not be replaced. 
Test Product, Dose, and Mode of Administration  
• 20 mg dose: Two IW-1973 Tablets, 10 mg administered orally 
• 40 mg dose: Two IW-1973 Tablets, 20 mg administered orally 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Reference Therapy, Dosage, and Mode of Administration 
Placebo to match IW-1973 Tablets: Two tablets administered orally 
Study Periods  
The study will consist of 3 periods (see Study Schematic). 
Screening Period: The Screening Period will begin with the signature of the informed consent 
form (ICF) at the Screening Visit and may last up to 45 days. At the Screening Visit (which can 
occur from Day -45 to Day -15), patients will undergo preliminary screening procedures to 
determine their eligibility. Eligible patients will return to the clinic for the Baseline Visit (Day 7 
±3) for baseline and eligibility assessments including 24-hour ambulatory blood pressure 
monitoring (ABPM). The end of the Screening Period will coincide with the beginning of the 
Treatment Period. 
Treatment Period: The Treatment Period will begin on Day 1 at Randomization (there is no 
Day 0) and will end after the End of Treatment Visit on Day 87 (±3). Patients will be stratified 
by baseline eGFR (ie, eGFR 30 to 45, >45 to 60, and >60 to 75 mL/min/1.73 m2) and 
randomized in a 1:1:1 ratio to receive 20 mg IW-1973, 40 mg IW-1973, or placebo for 
approximately 12 weeks. 
Dosing on Days 1 to 7 (±1) will be BID (twice daily), morning and evening; dosing on Day 8 
(±1) onward will be QD (once daily), 2 tablets in the morning.  
At the Randomization Visit on Day 1, patients will receive their morning dose of study drug in 
the clinic and will undergo safety, efficacy, and pharmacokinetic (PK) assessments, including 
blood and urine collections at prespecified times (Schedule of Events). Patients must stay in the 
clinic at least 6 hours postdose and may leave the clinic at the Investigator’s discretion 
following all study procedures.  
At the Week 1 Visit on Day 8 (±1), patients will return to the clinic and receive their first QD 
dose of study drug in the clinic. Patients will undergo safety, efficacy, and PK assessments, 
including blood and urine collections at prespecified times (see Schedule of Events). Patients 
must stay in the clinic at least 6 hours postdose and may leave the clinic at the Investigator’s 
discretion following all study procedures.  
At the Week 4 (Day 29 ±3), Week 8 (Day 57 ±3), and End of Treatment (Day 87 ±3) Visits, 
patients will return to the clinic for study drug administration; safety, efficacy, and PK 
assessments; and study drug supply, if applicable (see Schedule of Events). 
Follow-up Period: The Follow-up Period will begin immediately after the End of Treatment 
Visit and will last for 28 (±3) days. At the Follow-up Visit on Day 115 (±3), patients will return 
to the clinic for final study assessments (see Schedule of Events). 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Study Schematic  
 
Study Drug Administration 
During Week 1, patients will take study drug BID (2×/day), 1 tablet in the morning and 1 tablet 
approximately 12 hours later in the evening, preferably at approximately the same times each 
day. From the Week 1 Visit (Day 8 ±1) on, patients will take study drug QD (1×/day), 2 tablets 
in the morning, preferably at approximately the same time each day. Patients should take study 
drug with water, may take study drug with or without food, and, for QD dosing, may swallow 
tablets together, if desired. On study visit days, patients will receive their study drug dose in the 
clinic (on Randomization Day, patients will receive only their morning dose in the clinic). 
Study visits should be scheduled in the morning to accommodate regular dosing schedule. 
Duration of Treatment 
Patients will receive daily study drug for up to 90 days. Total patient participation will be 131 
to 163 days, including the Screening, Treatment, and Follow-up Periods. 
Dose Reduction 
Per Investigator discretion, on a per-patient basis, dose may be reduced by half, ie, from 
2 tablets daily to 1 tablet daily (in the morning). Each patient’s dose may only be reduced once 
and may not be increased after reduction. Investigators should notify the Medical Monitor of all 
decisions to dose reduce on a per-patient basis.
Follow-up
Visit
(Day 115 ±3)
Screening
Visit
(Day -45 to -15)
Randomization
Visit
(Day 1)
End of Treatment
Visit
(Day 87 ±3)
Screening 
Period 
Treatment
Period
Follow-up 
Period
15 to 45 days
87 (±3) days
28 (±3) days
Week 1 
Visit
(Day 8 ±1)
Baseline
Visit
(Day -7 ±3)
Week 4
Visit
(Day 29 ±3)
Week 8
Visit
(Day 57 ±3)
40 mg IW-1973
20 mg IW-1973
Placebo
BID
QD
1
2 to 12
Dosing
Week
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Individual Stopping Criteria and Data Monitoring Committee Reviews 
If any events included in the table below are reported during the study and are judged to be both 
study drug related and a serious adverse event (SAE; per causality and SAE definitions in the 
protocol), individual stopping criteria or Data Monitoring Committee (DMC) review will be 
triggered as described below. The inclusion of these AEs is based on the clinical experience 
with IW-1973, the prescribing information for riociguat, and the patient population for this 
study. 
 
Treatment-emergent,  
Study Drug-related SAE Category 
# of patients to 
trigger DMC review 
Renal failure  
(eGFR <15 mL/min/1.73 m2; dialysis or renal transplant indicated) 
2 
Spontaneous bleeding events  
(eg, hemoptysis, subarachnoid or subdural hemorrhage, hematemesis, 
hematochezia) 
2 
Symptomatic hypotension-related events 
(eg, syncope) 
2 
DMC=Data Monitoring Committee; eGFR=estimated glomerular filtration rate; SAE=serious adverse event 
 
Individual  
On an individual basis, a patient will be discontinued from study drug dosing if 1 or more SAEs 
from the table is reported. At the Investigator’s or Sponsor’s discretion, any AE(s) of concern 
can likewise be the basis for patient discontinuation from the trial. 
Study 
An independent DMC will review trial safety data. The DMC will comprise experts in 
cardiovascular and/or renal disease and/or diabetes and a biostatistician who have experience in 
clinical trials and are not involved in the conduct of this trial.  
Periodic safety review meetings will be scheduled after 30 subjects have been randomized or 
5 months after the first subject is randomized (whichever is earlier) and when approximately 
1/3 and 2/3 of patients have completed or discontinued treatment. The committee will review 
accumulated AE data and recommend trial continuation, continuation with modification, or 
termination. For these periodic reviews, the DMC will be provided with summaries of AE and 
blood pressure data. If a safety/tolerability signal or concerning AE imbalance is identified at a 
review, the committee can request unblinding of the masked treatment groups and may request 
additional safety data (eg, vital signs, concomitant medications).  
The DMC will also be required to perform an ad hoc review if SAEs from the same category in 
the above table are reported at the incidence indicated in the table shown above (eg, 2 patients 
with spontaneous bleeding SAEs). In this circumstance, the DMC will be provided with 
narrative descriptions and all relevant clinical supporting documentation related to the SAEs. 
Upon request, the unblinded treatment codes and dose the subjects with the SAEs received will 
be made available to the committee.  
In addition to the periodic and ad hoc reviews, during the trial, committee members will be 
provided with blinded reports on all SAEs. The DMC or the Sponsor may request ad hoc 
meetings at any time. 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Study Endpoints 
Primary Endpoints 
• Primary Safety:  Incidence of TEAEs and study drug-related TEAEs  
• Primary Efficacy: Change from baseline in UACR over Weeks 8 and 12 
Statistical Methods  
Sample Size Determination 
Using an estimate of standard deviation of 0.67, a sample size of 40 patients per treatment 
group would provide approximately 80% power to detect a mean between-group difference 
of -0.376 units in change from baseline in log-transformed UACR over 12 weeks, with a one-
sided significance level of 0.05 for at least 1 dose versus placebo comparison. This difference 
corresponds to a 31% between-group reduction of geometric mean change from baseline in 
UACR. Assuming a drop-out rate of 20%, approximately 150 patients will be randomly 
assigned in a 1:1:1 ratio (approximately 50 patients per treatment group) to 20 mg IW-1973, 
40 mg IW-1973, or placebo. 
Analysis Populations 
Safety Population: The Safety Population will consist of all randomized patients who receive at 
least 1 dose of study drug. Patients in this population will be evaluated according to the 
treatment they actually received. 
Intent-to-Treat (ITT) Population: The ITT Population will consist of all randomized patients 
who receive at least 1 dose of study drug. Patients in this population will be evaluated 
according to the treatment group they were assigned at Randomization. 
PK Population: The PK Population will consist of all randomized patients who receive at least 
1 dose of study drug and have at least 1 postdose PK parameter assessment. 
Per-Protocol (PP) Population: The PP Population will consist of all ITT patients who did not 
have any major protocol deviations or dose reduction.  
Efficacy Analyses 
Corresponding with the primary efficacy objective of the trial, the primary inference for 
hypothesis testing is the treatment difference between the placebo group and the IW-1973 
groups on the change from baseline in log UACR over Weeks 8 and 12. The primary efficacy 
analysis will be conducted using the ITT population using a mixed-effects model repeated 
measures (MMRM) analysis with change from baseline in log-transformed UACR as the 
response variable, treatment, site, visit, treatment-by-visit interaction, and baseline eGFR 
stratum as fixed effects, and baseline log UACR and baseline mean arterial pressure as 
covariates with unstructured as the variance-covariance structure. Treatment differences 
between the pooled IW-1973 dose groups and the placebo group will be estimated overall. The 
null hypothesis of the test will be interpreted as equality between the placebo and pooled 
treatment groups, and rejection of the null hypothesis as evidence that the pooled IW-1973 
groups have a greater effect on lowering UACR than the placebo group. If the null hypothesis 
is rejected, the nature of these differences will be explored further by estimating the treatment 
differences between each IW-1973 dose group and the placebo group overall and at each 
assessment timepoint. Least square (LS) means, and LS mean differences between each 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 10 of 106 
TABLE OF CONTENTS 
STUDY IDENTIFICATION ...........................................................................................................2
SYNOPSIS .......................................................................................................................................3
LIST OF ABBREVIATIONS AND DEFINITIONS OF TERMS ................................................17
ELIGIBILITY CRITERIA .............................................................................................................21
INCLUSION CRITERIA .........................................................................................................21
EXCLUSION CRITERIA .......................................................................................................22
SCHEDULE OF EVENTS ............................................................................................................25
1.
INTRODUCTION .................................................................................................................28
1.1
DIABETIC NEPHROPATHY .....................................................................................28
1.2
THE NO-SGC-CGMP PATHWAY ............................................................................29
1.3
RATIONALE FOR USE OF AN SGC STIMULATOR IN DIABETIC 
NEPHROPATHY ........................................................................................................30
1.4
IW-1973 BACKGROUND ..........................................................................................30
1.4.1
Nonclinical Studies in Support of DN ...............................................................30
2.
STUDY OBJECTIVES ..........................................................................................................32
3.
INVESTIGATIONAL PLAN ................................................................................................33
3.1
OVERALL STUDY DESIGN AND PLAN ................................................................33
3.2
DISCUSSION OF STUDY DESIGN AND CONTROL GROUP ..............................35
3.3
STUDY DURATION ..................................................................................................35
3.4
STUDY POPULATION ..............................................................................................35
3.4.1
Study Population Description ............................................................................35
3.4.2
Removal of Patients from Therapy or Assessment ............................................36
3.4.3
Early Termination Procedures ...........................................................................37
3.4.4
Replacement Procedures ....................................................................................37
3.5
STUDY TREATMENT(S) ..........................................................................................37
3.5.1
Description of Treatment(s) ...............................................................................37
3.5.1.1
Investigational Product ............................................................................37
3.5.1.2
Placebo .....................................................................................................37
3.5.1.3
Packaging and Labeling ...........................................................................37
3.5.1.4
Dosage......................................................................................................38
3.5.1.5
Storage and Accountability ......................................................................38
3.5.2
Method of Assigning Patients to Treatment Groups ..........................................39
3.5.3
Selection of Dosage in the Study .......................................................................39
3.5.4
Selection and Timing of Dose for Each Patient and Dose Reduction ...............40
3.5.4.1
Study Drug Administration ......................................................................40
3.5.4.2
Dose Reduction ........................................................................................40
3.5.5
Treatment Compliance .......................................................................................40
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Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
20 December 2017 
Confidential 
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3.8.12
Pharmacokinetic Assessments ...........................................................................57
3.8.13

3.9
STUDY ACTIVITIES .................................................................................................58
3.9.1
Screening Period (Day -45 to Day -1) ...............................................................58
3.9.1.1
Screening Visit (Days -45 to -15) ............................................................58
3.9.1.2
Baseline Visit (Days –7 ±3) .....................................................................59
3.9.2
Treatment Period (Day 1 to Day 87 ±3) ............................................................59
3.9.2.1
Randomization Visit (Day 1) ...................................................................59
3.9.2.2
Week 1 Visit (Day 8 ±1) ..........................................................................60
3.9.2.3
Week 4 Visit (Day 29 ±3) ........................................................................61
3.9.2.4
Week 8 Visit (Day 57 ±3) ........................................................................62
3.9.2.5
End of Treatment Visit (Day 87 ±3) ........................................................63
3.9.3
Follow-up Period (Day 87 ±3 to Day 115 ±3) ...................................................64
3.9.3.1
Follow-up Visit (Day 115 ±3) ..................................................................64
4.
STUDY ENDPOINTS ...........................................................................................................65
4.1
PRIMARY ENDPOINTS ............................................................................................65
4.1.1
Primary Safety ...................................................................................................65
4.1.2
Primary Efficacy ................................................................................................65
4.2
EXPLORATORY ENDPOINTS .................................................................................65






5.
STATISTICAL METHODS ..................................................................................................67
5.1
GENERAL CONSIDERATIONS ...............................................................................67
5.2
DETERMINATION OF SAMPLE SIZE ....................................................................67
5.3
ANALYSIS POPULATIONS .....................................................................................67
5.4
PATIENT DISPOSITION ...........................................................................................68
5.5
DEMOGRAPHICS AND BASELINE CHARACTERISTICS...................................68
5.6
DRUG EXPOSURE AND COMPLIANCE ................................................................68
5.7
PRIOR AND CONCOMITANT MEDICATIONS .....................................................68
5.8
MAJOR PROTOCOL DEVIATIONS .........................................................................69
5.9
EFFICACY ANALYSES ............................................................................................69
5.9.1
Controlling for Multiplicity ...............................................................................70
5.10
SAFETY ANALYSES.................................................................................................70
5.10.1
Adverse Events ..................................................................................................70
5.10.2
Clinical Laboratory Parameters .........................................................................71
5.10.3
Vital Signs ..........................................................................................................71
5.10.4
ECGs ..................................................................................................................71
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IW-1973 Tablets 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
20 December 2017 
Confidential 
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5.10.5

5.11
PK 
 .....................................................................................72
5.12











5.13
DATA MONITORING COMMITTEE .......................................................................73
5.14
INTERIM ANALYSIS (OPTIONAL) ........................................................................74
5.15
CHANGES IN THE CONDUCT OF THE STUDY OR PLANNED ANALYSES ...74
6.
ETHICAL CONSIDERATIONS ...........................................................................................76
6.1
INSTITUTIONAL REVIEW BOARD ........................................................................76
6.2
PATIENT INFORMATION AND INFORMED CONSENT .....................................76
7.
INVESTIGATORS AND STUDY ADMINISTRATIVE STRUCTURE ............................78
7.1
GENERATION OF STUDY RECORDS ....................................................................78
7.2
DATA QUALITY ASSURANCE ...............................................................................79
7.3
ELECTRONIC CASE REPORT FORMS AND DATA MANAGEMENT ...............79
7.4
STUDY MONITORING .............................................................................................79
8.
STUDY SPONSORSHIP.......................................................................................................81
8.1
INVESTIGATOR AND STUDY TERMINATION ...................................................81
8.2
REPORTING AND PUBLICATION ..........................................................................81
9.
INVESTIGATOR OBLIGATIONS ......................................................................................82
9.1
DOCUMENTATION ..................................................................................................82
9.2
PERFORMANCE ........................................................................................................84
9.3
USE OF INVESTIGATIONAL MATERIALS ...........................................................84
9.4
RETENTION AND REVIEW OF RECORDS ...........................................................84
9.5
PATIENT CONFIDENTIALITY ................................................................................85
10. REFERENCE LIST ...............................................................................................................86
11. SPONSOR SIGNATURES ....................................................................................................89
12. INVESTIGATOR’S SIGNATURE .......................................................................................90
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 14 of 106 
LIST OF IN-TEXT TABLES 
Table 1.
Key Study Participants .........................................................................................2
Table 2.
Dosage by Week ................................................................................................38
Table 3.
Categories of SAEs Triggering Individual Stopping Criteria and Safety 
Committee Review ............................................................................................44
Table 4.
Clinical Laboratory Tests ...................................................................................50
 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 15 of 106 
LIST OF IN-TEXT FIGURES 
Figure 1.
Study Schematic ................................................................................................33
 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 16 of 106 
LIST OF APPENDICES 
Appendix 1
Prohibited Medicines and Supplements .............................................................91
Appendix 2

Appendix 3

Appendix 4

 
 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 17 of 106 
LIST OF ABBREVIATIONS AND DEFINITIONS OF TERMS 
Abbreviation 
Term 
ABPM 
ambulatory blood pressure monitoring 
ACEi 
angiotensin-converting enzyme inhibitor 
AE 
adverse event 
ALT 
alanine aminotransferase 
AOBP 
automated office blood pressure 
ARB 
angiotensin receptor blocker 
AST 
aspartate aminotransferase 
 
 
BID 
twice daily 
BMI 
body mass index (kg/m2) 
BP 
blood pressure 
BUN 
blood urea nitrogen 
CBC 
complete blood count 
cGMP 
cyclic guanosine 3’, 5’-monophosphate 
CKD-EPI 
Chronic Kidney Disease Epidemiology Collaboration  
 
 
CMH 
Cochran-Mantel-Haenszel 
CYP3A 
cytochrome P450 3A 
DBP 
diastolic blood pressure 
DMC 
Data Monitoring Committee 
DN 
diabetic nephropathy 
DNA 
deoxyribonucleic acid 
ECG 
electrocardiogram 
eCRF 
electronic case report form 
EDC 
electronic data capture 
eGFR 
estimated glomerular filtration rate (mg/mL/1.73 m2) 
eNOS 
endothelial nitric oxide synthase 
 
 
ESRD 
end-stage renal disease 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Abbreviation 
Term 
FDA 
Food and Drug Administration 
FPG 
fasting plasma glucose 
FPI 
fasting plasma insulin  
GCP 
good clinical practice 
GGT 
gamma glutamyl transferase  
GI 
gastrointestinal 
GLP 
good laboratory practice 
h 
hour(s)  
HbA1c 
hemoglobin A1c (glycated hemoglobin) 
HBsAG 
hepatitis B surface antigen 
HCV 
hepatitis C virus 
HDPE 
high-density polyethylene 
hERG 
ether-à-go-go related gene 
HIV 
human immunodeficiency virus 
HOMA-IR 
homeostatic model assessment to quantify insulin resistance 
HPF 
high power field 
HR 
heart rate 
IC50 
half maximal inhibitory concentration 
ICF  
informed consent form 
ICH 
International Conference on Harmonisation 
IRB 
Institutional Review Board 
ITT 
intent to treat 
IUD 
intrauterine device 
IWRS 
interactive web response system 
KDIGO 
Kidney Disease: Improving Global Outcomes 
 
 
kg 
kilogram 
kg/m2 
kilograms/meters squared (body mass index) 
LDH 
lactate dehydrogenase  
L-NAME 
L-nitroarginine methyl ester 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Abbreviation 
Term 
LS 
least square 
m 
minute  
MAD 
multiple ascending dose 
MAP 
mean arterial pressure 
MCH 
mean corpuscular hemoglobin 
MCHC 
mean corpuscular hemoglobin concentration 
MCV 
mean corpuscular volume 
MedDRA 
Medical Dictionary for Regulatory Activities 
MEMS 
Medication Event Monitoring System 
mg 
milligram 
MI 
myocardial infarction 
mL 
milliliter 
mm Hg 
millimeters of mercury 
MMRM 
mixed-effects model repeated measures 
MPV 
mean platelet volume 
msec 
millisecond 
NO 
nitric oxide 
NT-proBNP 
N-terminal pro B-type natriuretic peptide  
NYHA 
New York Heart Association  
PEG 
polyethylene glycol 
pd 
postdose 
 
 
PDE 
phosphodiesterase 
 
 
 
 
PID 
patient identification 
PK 
pharmacokinetic(s) 
PKG 
protein kinase G 
PP 
per protocol 
PRN 
pro re nata [ie, as needed]  
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
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Abbreviation 
Term 
PT 
preferred term 
QD 
once daily  
QTcF 
QT interval corrected using Fridericia’s formula 
RAAS 
renin-angiotensin-aldosterone system 
SAE 
serious adverse event 
SBP 
systolic blood pressure 
Scr 
serum creatinine 
sGC 
soluble guanylate cyclase 
SOC 
system organ class 
tau 
dosing interval 
TEAE 
treatment-emergent adverse event 
UACR 
urine albumin creatinine ratio 
 
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IW-1973 Tablets 
 
Ironwood Pharmaceuticals, Inc. 
Clinical Trial Protocol: C1973-203 Amendment 4 
 
20 December 2017 
 
Confidential 
Page 21 of 106 
ELIGIBILITY CRITERIA 
INCLUSION CRITERIA 
Patients must meet all of the following criteria to be eligible for enrollment in this study: 
1. Patient has signed an informed consent form (ICF) before any study-specific procedures are 
performed. 
2. Patient is an ambulatory male or female from 25 to 75 years old at the Screening Visit. 
3. Patient has type 2 diabetes diagnosed by a physician or nurse practitioner 6 months before 
the Screening Visit, has been on 1 antihyperglycemic medication for 12 weeks preceding 
the Randomization Visit, and has been on a stable regimen (ie, same drug and same dose) of 
1 antihyperglycemic medication for 28 days preceding the Randomization Visit. 
(Modification of short-acting insulin throughout the Screening Period will not affect 
eligibility.) 
4. Patient has been on a stable regimen (ie, same drug and dose) of an angiotensin-converting 
enzyme inhibitor (ACEi) or an angiotensin receptor blocker (ARB), for 28 days preceding 
the Randomization Visit and is expected to remain on their regimen through the Follow-up 
Visit. (Note: These medications may be modified during the study if medically necessary.) 
5. If patient is on medications for hypertension, regimen (drug[s] and dose[s]) must be stable 
for 28 days preceding the Randomization Visit and is expected to remain stable through the 
Follow-up Visit. (Note: Medications for antihypertension may be modified during the study 
if medically necessary.) 
6. Patient has the following:   
a. Estimated glomerular filtration rate (eGFR) 30 to 75 mL/min/1.73 m2 by the Chronic 
Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation (1) at the 
Screening and Baseline Visits 
b. Urine albumin creatinine ratio (UACR) >200 mg/g and <5000 mg/g at the Screening and 
Baseline Visits (at the Baseline Visit, the mean of the 2 first morning void tests will be 
used to determine eligibility) 
c. Serum albumin >3.0 g/dL at the Screening and Baseline Visits 
d. Hemoglobin A1c (HbA1c) 12% at the Screening and Baseline Visits 
e. Systolic blood pressure (BP) of 110 to 160 mm Hg based on the average of 3 seated 
automated office blood pressure (AOBP) measurements at the Screening and Baseline 
Visits 
7. Female patient must be postmenopausal (no menses for 12 consecutive months); surgically 
sterile (ie, bilateral oophorectomy, hysterectomy, or tubal sterilization [tie, clip, band, or 
burn]); must agree to completely abstain from heterosexual intercourse; or, if heterosexually 
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active, must agree to use 1 of the following methods of birth control from the date she signs 
the ICF until 60 days after the final dose of study drug: 
a. Progesterone implant or an intrauterine device (IUD) 
b. Combination of 2 highly effective birth control methods (eg, diaphragm with spermicide 
plus a condom, condom with spermicide plus a diaphragm or cervical cap, hormonal 
contraceptive [eg, oral and transdermal patch] plus a barrier method, partner with 
vasectomy [conducted 60 days before the Screening Visit or confirmed via sperm 
analysis] plus a hormone/barrier method).  
8. Male patients must be surgically sterile by vasectomy (conducted 60 days before the 
Screening Visit or confirmed via sperm analysis), must agree to completely abstain from 
heterosexual intercourse, or, if heterosexually active, must agree to use a combination of 
2 highly effective birth control methods (eg, condom with spermicide plus partner IUD, 
condom with spermicide plus a partner diaphragm or cervical cap, partner hormonal 
contraceptive [including progesterone implant] plus a barrier method, or postmenopausal 
partner [no menses for 1 year or 12 consecutive months] plus barrier method) from the 
Screening Visit through 60 days after the final dose of study drug. 
9. Patient must agree not to make any major lifestyle (eg, diet, exercise) changes from the 
Screening Visit through the Follow-up Visit. 
 
EXCLUSION CRITERIA 
Patients who meet any of the following criteria will not be eligible to participate in the study: 
1. Patient has a history of secondary hypertension (ie, renal artery stenosis, primary 
aldosteronism, or pheochromocytoma). 
2. Patient has a body mass index (BMI) <20 or >45 kg/m2 at the Screening Visit. 
3. Patient has elevated (>1.5× the upper limit of normal as defined by laboratory) levels of 
alanine aminotransferase (ALT) or aspartate aminotransferase (AST) at the Screening or 
Baseline Visits. 
4. Patient has hemoglobin level <9 g/dL at the Screening or Baseline Visit. 
5. Patient has a 12-lead electrocardiogram (ECG) demonstrating severe bradycardia (heart rate 
<50 beats per minute) or QTcF is 450 msec for male patients or is 470 msec for female 
patients at the Screening or Baseline Visit. (NOTE: If on initial ECG, QTcF exceeds the 
limit, the ECG will be repeated 2 more times, and the average of the 3 QTcF values will be 
used to determine the patient's eligibility at the Screening and Baseline Visits.) 
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6. Patient has any history of platelet dysfunction, hemophilia, von Willebrand disease, 
coagulation disorder, other bleeding diathesis, or significant, nontraumatic bleeding episodes, 
such as from a gastrointestinal (GI) source. 
7. Patient has hepatic impairment defined as Child-Pugh A, B, C. 
8. Patient has significant comorbidities (eg, malignancy, advanced liver disease, pulmonary 
hypertension, pulmonary fibrosis, lung disease requiring supplemental oxygen) or other 
significant conditions, including clinically significant abnormality(ies) in laboratory values, 
that, in the Investigator’s opinion, would limit the patient’s ability to complete or participate 
in this clinical study; has been hospitalized for cardiovascular, renal, or metabolic cause in 
the 3 months before the Screening Visit; or has a life expectancy of less than 1 year. 
9. Patient has a history of a chronic GI disease, which in the Investigator's opinion could cause 
significant GI malabsorption. 
10. Patient with known nondiabetic renal disease (eg, known polycystic kidney disease, focal 
segmental glomerulosclerosis) or nondiabetic etiology of renal function compromise. 
Concomitant hypertension-associated nephrosclerosis superimposed on diabetic nephropathy 
is acceptable. 
11. Patient has had prior dialysis, renal transplant, or planned renal transplant. (Prior dialysis 
does not include transient, short-term dialysis indicated for an illness or during acute 
hospitalization. This “transient” dialysis must have occurred >3 months prior to 
Randomization, must have been <7 days in duration, and the current eGFR must be stable 
and within the eligible range [>30 mL/min/1.73 m2].) 
12. Patient has clinically active, symptomatic, or unstable coronary artery or heart disease within 
the 3 months before the Screening Visit, defined as 1 of the following: 
a. Hospitalization for myocardial infarction (MI), unstable angina, or heart failure 
b. New-onset angina with positive functional study or coronary angiogram revealing 
stenosis 
c. Coronary revascularization procedure 
13. Patient has a documented history of New York Heart Association (NYHA) Class III or IV 
heart failure.(2)  A prior brief/transient NYHA Class III or IV designation is not exclusionary 
provided that, at Randomization, the status is Class II or better and has been stable without 
deterioration into a more severe class for 3 months.  
14. Patient has a positive hepatitis panel (hepatitis B surface antigen [HBsAg] and antihepatitis C 
virus [HCV]) or human immunodeficiency virus (HIV) antibody at the Screening Visit. 
15. Patient has a history of viral or bacterial infection within 4 weeks of the Screening Visit. 
16. Patient has had surgery with general anesthesia in the 12 weeks before the Screening Visit or 
has scheduled or planned surgery with general anesthesia during the study. 
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17. Patient has a history of active alcoholism or drug addiction during the year before the 
Screening Visit or, at the Screening Visit, has a positive drug screen for drugs not legally 
prescribed. 
18. Patient is taking specific inhibitors of phosphodiesterase 5 (PDE5), nonspecific inhibitors of 
PDE5 (including dipyridamole and theophylline), any supplements for the treatment of 
erectile dysfunction, riociguat, or nitrates or nitric oxide (NO) donors in any form. These 
medications and supplements are prohibited from 7 days before Randomization through the 
duration of the study.  
Patient is taking strong cytochrome P450 3A (CYP3A) inhibitors, examples of which include 
azole antifungals, macrolide antibiotics, protease inhibitors, and diltiazem. These 
medications and excessive grapefruit intake are prohibited 14 days before Randomization 
through the duration of the trial. 
See Appendix 1 for a more detailed list of prohibited medications and supplements. 
19. Female patient who may wish to become pregnant and/or plan to undergo egg donation or 
egg harvesting for current or future in vitro fertilization during the study and for at least 
60 days after the final dose of study drug. 
20. Male patient unwilling to refrain from sperm donation during the study and for at least 
60 days after the final dose of study drug. 
21. Patient has a history of clinically significant hypersensitivity or allergies to any of the 
inactive ingredients contained in the active or placebo drug products. 
22. Patient has previously received IW-1973 in a study, or received an investigational drug 
during the 30 days or 5 half-lives of that investigational drug (whichever is longer) before the 
Screening Visit, or is planning to receive another investigational drug at any time during the 
study. 
23. Female patient is pregnant or nursing at the Screening Visit. Nursing is not allowed from the 
Screening Visit through the Follow-up Visit. 
24. Patient will not be able to adhere to the trial assessment schedule, or, in the clinical judgment 
of the Investigator, the patient is otherwise not suitable for the trial. 
 
Note: Screening Visit assessments may take place over more than 1 day. Patients may be 
rescreened should they discontinue in the Screening Period due to visit window deviations or 
other administrative reasons. In addition, laboratory values or BPs that are outside the range 
specified in the protocol may be repeated to confirm eligibility during the Screening Period at the 
Investigator’s discretion after consultation with the Medical Monitor.
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SCHEDULE OF EVENTS 
 
Visit Days ĺ 
Study Procedure Ļ 
Screening Period 
Treatment Period 
Follow-up 
Period 
Screening 
Visit 
(Day -45 
to -15) 
Baseline 
Visit 
(Day -7 
±3) 
Randomization 
Visit 
(Day 1) 
Week 1 Visit 
(Day 8 ±1) 
Week 4 Visit 
(Day 29 ±3) 
Week 8 Visit 
(Day 57 ±3) 
End of 
Treatment 
Visit 
(Day 87 ±3) 
Follow-up 
Visit 
(Day 115 ±3) 
ICF signed 
X 
 
 
 
 
 
 
 
Demographics 
X 
 
 
 
 
 
 
 
Medical history 
X 
 
 
 
 
 
 
 
Prior & concomitant meds 
X 
X 
X 
X 
X 
X 
X 
X 
Inclusion/exclusion 
evaluation/review 
X 
X 
X 
 
 
 
 
 
Physical exam 
X 
 
 
 
 
 
X 
 
Hepatitis (HBsAg, HCV) & 
HIV screen 
X 
 
 
 
 
 
 
 
Drug screen (a) 
X 
 
 
 
 
 
 
 
Urine pregnancy test (b) 
X 
X 
predose 
predose 
predose 
predose 
predose 
X 
Weight (W) & height (H) 
W, H 
W 
W 
W 
W 
W 
W 
W 
12-lead ECG (c) 
X 
X 
 
 
 
 
predose 
 
Respiratory rate and oral 
temperature  
X 
 
pre: 0 (30m) 
pd: 1h (±15m) 
pre: 0 (30m) 
pd: 1h (±15m)
 
 
X 
X 
Seated pulse and BP (d) 
X 
X 
 
 
 
 
 
 
First-void urine for UACR (e) 
X 
preVisit 
preVisit 
preVisit 
 preVisit 
 preVisit 
 preVisit 
preVisit 
Issue UACR sample supplies 
X 
X 
X 
X 
X 
X 
X 
 
Urinalysis sample (f) 
X 
X 
 
 
 
 
predose 
X 
Serum chemistry, coagulation, 
hematology (f) 
X 
X 
serum creatinine 
& glucose only 
pre: 0 (30m) 
serum creatinine 
& glucose only 
pre: 0 (30m) 
pre: 0 (30m) 
serum creatinine 
& glucose only 
pre: 0 (30m) 
pre: 0 (30m)
X 
Hemoglobin A1c (f) 
X 
X 
 
pre: 0 (30m) 
pre: 0 (30m) 
pre: 0 (30m) 
pre: 0 (30m)
X 
Adverse event evaluations 
X 
X 
X 
X 
X 
X 
X 
X 
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Visit Days ĺ 
Study Procedure Ļ 
Screening Period 
Treatment Period 
Follow-up 
Period 
Screening 
Visit 
(Day -45 
to -15) 
Baseline 
Visit 
(Day -7 
±3) 
Randomization 
Visit 
(Day 1) 
Week 1 Visit 
(Day 8 ±1) 
Week 4 Visit 
(Day 29 ±3) 
Week 8 Visit 
(Day 57 ±3) 
End of 
Treatment 
Visit 
(Day 87 ±3) 
Follow-up 
Visit 
(Day 115 ±3) 
Fasting plasma glucose & 
insulin (f) 
X 
pre: 0 (30m) 
pre: 0 (30m) 
pre: 0 (30m) 
pre: 0 
(30m) 
Urine cotinine 
predose 
24- or 12-h ABPM (h)
X (24h)
X (12h) 
X (12h) 
X (24h) 
Return of ABPM monitor 
X 
X 
X 
X 
Orthostatic (seated to 
standing) pulse and BP (i) 
pre: 0 (30m) 
pd: 1,2,4,6h 
(±15m) 
pre: 0 (30m) 
pd: 1,2,4,6h 
(±15m) 
pre: 0 (30m) 
pre: 0 (30m) 
pre: 0 
(30m) 
X 
Randomization
 
X
MEMS instruction/review 
X 
X
X
X
Study drug dispensed 
X 
X 
X 
In-clinic study drug 
administration (j) 
X
X
X
X
X
Study drug return (k)
X
X
X
X
Pharmacokinetic blood 
samples  
pre: 0 (30m) 
pd: 1,3,6h 
(±15m) 
pre: 0 (30m) 
pd: 1,3,6h 
(±15m) 
pre: 0 (30m) 
pre: 0 (30m) pre: 0 (30m) 
pd: 3h (±15m)
X 
Study completion 
X
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1. 
INTRODUCTION 
1.1 
DIABETIC NEPHROPATHY 
Diabetic nephropathy (DN), also known as diabetic kidney disease, is a common and serious 
complication of Type 1 and Type 2 diabetes mellitus and is characterized by pathological urinary 
albumin excretion, glomerular lesions, hypertension, and progressive loss of renal function.(3-5) 
Diagnosis is based on the presence of albuminuria (urine albumin creatinine ratio [UACR] 
>30 mg/g) and/or reduced estimated glomerular filtration rate (eGFR <90 mL/min/1.73 m2) in 
patients with diabetes.(6) The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical 
Practice Guideline (7) provides a kidney disease classification system and risk-stratifies patients 
based on levels of albuminuria and eGFR.  
Diabetic nephropathy is the leading cause of end-stage renal disease (ESRD) in the United States 
and other industrialized countries.(8,9) Diabetic nephropathy is also a major risk factor for 
cardiovascular disease as well as the single strongest predictor of mortality in patients with 
diabetes. An estimated 20% to 40% of patients with diabetes develop DN, with higher rates seen 
in middle-aged African Americans, Hispanics, and American Indians.(3,9) The prevalence of 
DN is increasing in the United States and globally with the increasing prevalence of 
diabetes.(9,10) The estimated number of persons in the United States with DN has increased 
from 3.9 million in 1988-1994 to 6.9 million in 2005-2008.(9) 
Current first-line therapy for DN includes glycemic and blood pressure (BP) control and 
treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors: angiotensin-converting-
enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs).(3,4,6) RAAS inhibitors 
have been shown in clinical trials to reduce albuminuria and delay progression to ESRD and 
renal replacement therapy. However, the current standard of care does not prevent progression to 
ESRD, and the prevalence of DN has not declined with increased use of RAAS inhibitors and 
glucose-lowering medications.(9) The burden of caring for DN patients is extremely high due to 
the cost of treating ESRD as well as the strong association of DN with cardiovascular disease.(3) 
New therapies for DN are urgently needed. 
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1.2 
THE NO-SGC-CGMP PATHWAY 
Although the pathogenesis of DN is not completely understood, nitric oxide (NO) deficiency 
resulting from endothelial dysfunction is believed to play an important role.(11,12) In the healthy 
endothelium, the enzyme endothelial nitric oxide synthase (eNOS) catalyzes the conversion of 
L-arginine to NO. Locally generated NO stimulates soluble guanylate cyclase (sGC) to produce 
cyclic guanosine 3’, 5’-monophosphate (cGMP), which acts on downstream targets including 
cGMP-dependent protein kinases (PKG), phosphodiesterases, and ion channels. NO-sGC-cGMP 
signaling promotes the relaxation of vascular smooth muscles cells and blocks endothelial cell 
activation and cytokine-induced injury in the kidney and elsewhere.(13) Intracellular cGMP also 
plays a role in processes that affect vascular proliferation (14), fibrosis (15,16), and 
inflammation.(17)  
Diabetes patients show evidence of vascular endothelial dysfunction (18,19), and endothelial 
dysfunction promotes the progression of DN.(18) In patients with diabetes, endothelial NO 
bioavailability may be reduced by several mechanisms, including the generation of advanced 
glycation end-products, increased uric acid levels, increased levels of the eNOS inhibitor 
asymmetric dimethyl arginine, and increased oxidative stress.(11,12) High levels of glucose also 
induce the uncoupling of endothelial eNOS, resulting in decreased production of NO and 
increased production of superoxide. Superoxide can react with NO to produce peroxynitrite, 
further reducing NO bioavailability. 
Animal model data suggest that NO deficiency plays a role in the pathogenesis of DN. Animal 
models of diabetes generally produce only early signs of kidney disease, but models of diabetes 
in the context of NO deficiency, such as the diabetic eNOS-knockout mouse model, show 
features more consistent with human DN, including nephrotic albuminuria, systemic 
hypertension, glomerular hypertension, tubulointerstitial damage, and glomerular ischemia and 
fibrosis.(11,20) In a rat model of obstructive nephropathy, treatment with the eNOS inhibitor 
L-nitroarginine methyl ester (L-NAME) resulted in increased renal fibrosis and apoptosis, 
reduced blood flow, and reduced filtration rates.(21) In another study using a sub-total 
nephrectomized rat model, eNOS inhibition by L-NAME resulted in impaired autoregulation of 
glomerular blood flow and increased renal injury.(22) Recently, Ueda et al (23) showed that 
endothelial NO is required for mitochondrial integrity in cultured podocytes. They also showed 
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that eNOS-knockout mice exhibit morphologic evidence of podocyte damage and develop 
oxidative stress associated with podocyte mitochondrial abnormalities. Overall, these data 
indicate that NO deficiency may be involved in producing renal damage by multiple 
mechanisms. 
1.3 
RATIONALE FOR USE OF AN SGC STIMULATOR IN DIABETIC 
NEPHROPATHY 
Pharmacologic stimulation of sGC could offer a new approach for treating DN.(24,25) By 
increasing intracellular cGMP levels, sGC stimulators could potentially compensate for deficient 
NO bioavailability and thereby improve renal endothelial function and attenuate or prevent renal 
inflammation and fibrosis. Both sGC stimulators (which act synergistically with NO on the 
native, heme-containing form of the enzyme) and sGC activators (which act independently of 
NO on the heme-free form of the enzyme) have shown activity in multiple animal models of DN 
and other kidney diseases.(24) For example, in the diabetic eNOS-knockout mouse model of DN, 
treatment with the sGC stimulator riociguat in combination with the ARB telmisartan reduced 
systemic BP, albuminuria, and renal interstitial fibrosis.(26) In another set of studies,(27) 
riociguat was found to reduce mortality, normalize systemic BP, and reduce renal damage in 
low- and high-renin models of hypertension in the rat. Furthermore, the sGC activator cinaciguat 
reversed impaired autoregulation of renal blood flow induced by L-NAME in rats.(28) In a 
recent study using the obese ZSF1 rat model of Type 2 DN, treatment with the sGC activator BI 
703704 resulted in significant reductions in albuminuria, glomerulosclerosis, and interstitial 
fibrosis, despite only modest reductions in systemic BP. Together, these nonclinical data provide 
the rationale for the investigation of sGC stimulators in patients with DN.  
1.4 
IW-1973 BACKGROUND 
For a detailed description of the properties of IW-1973 and the results of the nonclinical and 
clinical studies conducted thus far, please refer to the most recent Investigator’s Brochure.  
1.4.1 
Nonclinical Studies in Support of DN 
IW-1973 is a potent and selective stimulator of sGC. In vitro, IW-1973 was shown to sensitize 
sGC to endogenous NO, and to directly stimulate sGC independently of NO. IW-1973 also 
potently relaxed precontracted human subcutaneous resistance arteries ex vivo. Oral 
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administration of IW-1973 to normotensive and spontaneously hypertensive rats and to 
normotensive dogs was shown to elicit a dose-dependent decrease in systolic, diastolic, and 
mean arterial BP, as well as a concomitant rise in heart rate. 
IW-1973 stimulated purified human recombinant sGC to produce cGMP in a concentration-
responsive manner, both in the absence and in the presence of an NO donor. The EC50 value was 
267 nM in the presence of NO; the production of cGMP was lower in the absence of NO than in 
the presence of NO. In vitro, IW-1973 showed anti-fibrotic and anti-inflammatory effects in 
human renal proximal tubular cells. In the Dahl salt-sensitive rat model of hypertension and end-
organ damage, orally administered IW-1973 demonstrated a dose-dependent (1-10 mg/kg/day) 
reduction in BP that was sustained over a 6-week treatment period. Treatment with IW-1973 also 
decreased albuminuria and attenuated levels of serum biomarkers known to be involved in 
inflammatory and fibrotic processes. Histopathological analysis of the kidneys showed a clear 
reduction at all doses in glomerulosclerosis, interstitial fibrosis, vascular alterations and 
interstitial inflammation. Additionally, in this model, IW-1973 demonstrated significant 
reductions in heart hypertrophy and reduced levels of plasma N-terminal pro B-type natriuretic 
peptide (NT-proBNP), a marker of cardiac injury. In the ZSF1 rat model of DN, IW-1973 
(10 mg/kg/day) reduced mean arterial pressure (MAP), kidney and liver weight gain, urine 
volume, proteinuria, and fasting glucose in comparison with untreated controls. Similar effects 
were observed with IW-1973 in combination with enalapril. These results support investigation 
of IW-1973 as a potential treatment for DN. 
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2. 
STUDY OBJECTIVES 
Primary 
• To assess the safety and tolerability of oral IW-1973 when administered daily for 
approximately 12 weeks to adult patients with type 2 diabetes mellitus with albuminuria who 
are on a stable regimen of renin-angiotensin system inhibitors  
• To evaluate the effect of oral IW-1973 on renal function when administered daily for 
approximately 12 weeks to adult patients with type 2 diabetes mellitus with albuminuria who 
are on a stable regimen of renin-angiotensin system inhibitors 
 
Exploratory 
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3. 
INVESTIGATIONAL PLAN 
3.1 
OVERALL STUDY DESIGN AND PLAN 
This Phase 2, multicenter, randomized, double-blind, placebo-controlled, parallel-group study 
will evaluate 2 dose levels of IW-1973 compared with placebo. The study will enroll 
approximately 150 patients with type 2 diabetes mellitus and albuminuria who are on a steady 
regimen of a RAAS inhibitor, such as an ACEi or an ARB (see Eligibility Criteria). Patients will 
be stratified by baseline eGFR (ie, eGFR 30 to 45, >45 to 60, and >60 to 75 mL/min/1.73 m2) 
and randomized in a 1:1:1 ratio to receive daily 20 mg IW-1973 Tablets, 40 mg IW-1973 
Tablets, or placebo tablets for daily for approximately 12 weeks.  
Each patient will progress through 3 distinct study periods (Figure 1).  
Figure 1. 
Study Schematic 
 
 
Screening Period: The Screening Period will begin with the signature of the informed consent 
form (ICF) at the Screening Visit and may last up to 45 days. At the Screening Visit (which can 
occur from Day -45 to Day -15), patients will undergo preliminary screening procedures to 
determine their eligibility. Eligible patients will return to the clinic for the Baseline Visit 
(Day -7 ±3) for baseline and eligibility assessments including 24-hour ambulatory blood pressure 
Follow-up
Visit
(Day 115 ±3)
Screening
Visit
(Day -45 to -15)
Randomization
Visit
(Day 1)
End of Treatment
Visit
(Day 87 ±3)
Screening 
Period 
Treatment
Period
Follow-up 
Period
15 to 45 days
87 (±3) days
28 (±3) days
Week 1 
Visit
(Day 8 ±1)
Baseline
Visit
(Day -7 ±3)
Week 4
Visit
(Day 29 ±3)
Week 8
Visit
(Day 57 ±3)
40 mg IW-1973
20 mg IW-1973
Placebo
BID
QD
1
2 to 12
Dosing
Week
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monitoring (ABPM). The end of the Screening Period will coincide with the beginning of the 
Treatment Period. 
Treatment Period: The Treatment Period will begin on Day 1 at Randomization and will end 
after the End of Treatment Visit on Day 87 (±3). Patients will be stratified by baseline eGFR 
(ie, eGFR 30 to 45, >45 to 60, and >60 to 75 mL/min/1.73 m2) and randomized in a 1:1:1 ratio to 
receive daily 20 mg IW-1973, 40 mg IW-1973, or placebo daily for approximately 12 weeks; 
each daily dose will comprise 2 tablets. Dosing on Days 1 to 7 (±1) will be BID (twice daily), 
1 tablet in the morning and 1 tablet approximately 12 hours later in the evening; dosing on Day 8 
(±1) onward will be QD (once daily), 2 tablets in the morning.  
At the Randomization Visit on Day 1, patients will receive their morning dose of study drug in 
the clinic and will undergo safety, efficacy, and PK assessments, including blood and urine 
collections at prespecified times (see Schedule of Events). Patients must stay in the clinic at least 
6 hours postdose and may leave the clinic at the Investigator’s discretion following all study 
procedures.  
At the Week 1 Visit on Day 8 (±1), patients will return to the clinic and receive their first QD 
dose of study drug in the clinic. Patients will undergo safety, efficacy, and PK assessments, 
including blood and urine collections at prespecified times (see Schedule of Events). Patients 
must stay in the clinic at least 6 hours postdose and may leave the clinic at the Investigator’s 
discretion following all study procedures.  
At the Week 4 (Day 29 ±3), Week 8 (Day 57 ±3), and End of Treatment (Day 87 ±3) Visits, 
patients will return to the clinic for study drug administration; safety, efficacy, and PK 
assessments; and study drug, if applicable (see Schedule of Events). 
Follow-up Period: The Follow-up Period will begin immediately after the End of Treatment 
Visit and will last for 28 (±3) days. At the Follow-up Visit on Day 115 (±3), patients will return 
to the clinic for final study assessments (see Schedule of Events). 
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3.2 
DISCUSSION OF STUDY DESIGN AND CONTROL GROUP 
A double-blind, placebo-controlled, randomized study design was chosen to provide comparable 
treatment groups and minimal chance of selection or investigator bias in accordance with the 
concepts in ICH E10, Choice of Control Groups and Related Issues in Clinical Trials 
(International Conference on Harmonisation of Technical Requirements for Registration of 
Pharmaceuticals for Human Use, 2001). Placebo was chosen as the control so that the rate of 
spontaneously occurring AEs can be determined and to reduce the potential for bias in the 
reporting of AEs.  
This study has a 12-week Treatment Period to compare the effects of IW-1973 to a placebo 
control. The treatment duration of 12 weeks is sufficient in length to observe changes in UACR 
and hemodynamic measures, and in addition to establish a difference in treatment effect between 
IW-1973 and placebo in these measures.(29)  
Patients will be stratified by baseline eGFR to minimize the potential impact of baseline disease 
severity imbalance between treatment groups. Individual stopping criteria and Data Monitoring 
Committee safety reviews (Section 3.7) have been established to ensure that dosing will stop 
should a safety signal be detected. Patients will have a Follow-up Visit 28 (±3) days after the 
final dose of study drug to determine if any AEs have developed and if any AEs that were 
ongoing at the time of Discharge have resolved. In addition, at the Follow-up Visit as well at 
each study visit, female patients of reproductive potential will have a pregnancy test. 
3.3 
STUDY DURATION  
Patients will receive daily oral study drug for up to 90 days. Total patient participation will be 
131 to 163 days, including the Screening, Treatment, and Follow-up Periods.  
3.4 
STUDY POPULATION  
3.4.1 
Study Population Description 
This study will enroll approximately 150 adult patients with type 2 diabetes mellitus and 
albuminuria at multiple sites in the US. Patients must have type 2 diabetes diagnosed by a 
physician or nurse practitioner no fewer than 6 months before the Screening Visit and must have 
been taking at least 1 medication specifically for control of glycemia, either oral or injectable, for 
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at least 12 weeks before the Randomization Visit and have been on a stable regimen (ie, same 
drug and same dose) for at least 28 days preceding the Randomization Visit. To be eligible, 
patients must have a hemoglobin A1c (HbA1c) level of 12%. At Screening, patients must also 
have an eGFR of 30 to 75 mL/min/1.73 m2 (Chronic Kidney Disease Epidemiology 
Collaboration [CKD-EPI] creatinine equation), UACR >200 and <5000 mg/g, and serum 
albumin >3.0 g/dL. In addition, patients must have been on a stable regimen (ie, same drug and 
dose) of an ACEi or an ARB, for at least 28 days before the Randomization Visit. Patients must 
have systolic BP of 110 to 160 mm Hg, and if taking medications for hypertension, regimen must 
be stable for at least 28 days preceding the Randomization Visit. Patients with known 
nondiabetic renal disease are not eligible. 
Refer to Eligibility Criteria for full inclusion and exclusion criteria. 
3.4.2 
Removal of Patients from Therapy or Assessment 
A premature discontinuation will occur when a patient who has signed the ICF and has been 
randomized ceases participation in the study. 
A patient will be considered to have completed the study after completing the Follow-up Visit. 
Patients will be informed that they are free to withdraw from the study at any time and for any 
reason. The Investigator may remove a patient from the study if, in the Investigator’s opinion, it 
is not in the best interest of the patient to continue the study. Patients may also be discontinued 
from the study by the Investigator or the Sponsor at any time for any reason, including the 
following: 
• Adverse event(s) 
• Protocol violation, including lack of compliance 
• Lost to follow-up (every effort should be made to contact the patient; a certified letter should 
be sent) 
• Withdrawal of consent (attempts should be made to determine the reason for the patient 
withdrawing consent if possible) 
• Study termination by the Sponsor 
• Other reasons (eg, administrative reasons or pregnancy) 
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The Sponsor will be notified of any patient discontinuation after Randomization. The date the 
patient is withdrawn from the study and the reason for discontinuation will be recorded on the 
study termination form of the electronic case report form (eCRF). Patients who discontinue from 
the study will be followed until resolution of all their AEs or until the unresolved AEs are judged 
by the Investigator to have stabilized. 
If a patient does not return for a scheduled visit, the study center should contact the patient. An 
effort should be made to contact the patient, including sending a certified letter. In every case, 
the patient outcome, including lost to follow-up information, will be documented. 
3.4.3 
Early Termination Procedures 
Patients who prematurely discontinue study drug for any reason should complete the assessments 
required at the End of Treatment Visit at the time of their discontinuation and should complete 
the Follow-up Visit 28 ±3 days after their final dose of study drug.  
3.4.4 
Replacement Procedures 
Patients withdrawing from the study after Randomization will not be replaced. 
3.5 
STUDY TREATMENT(S) 
3.5.1 
Description of Treatment(s) 
3.5.1.1 
Investigational Product 
IW-1973 Tablets are 10 mg or 20 mg oral tablets and are white and round in appearance. 
3.5.1.2 
Placebo 
Placebo will match IW-1973 Tablets in appearance. The number of placebo tablets administered 
will match the number of tablets used for the IW-1973 treatment arm. 
3.5.1.3 
Packaging and Labeling 
IW-1973 and placebo tablets will be provided by PCI Pharma Services (Rockford, IL) on behalf 
of Ironwood in 100cc high-density polyethylene (HDPE) induction-sealed bottles, 35 tablets per 
bottle, containing two 1-gram mole desiccant sieves and 4-6 inches of purified polyester coil. 
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The bottles will be compatible with a Medication Event Monitor System cap (MEMSCap™, 
WestRock®; Sion, Switzerland) that will be interchanged at the clinical site.  
3.5.1.4 
Dosage 
Table 2 summarizes the dosage and dosing regimen for each treatment arm by Treatment Period 
week. 
Table 2. 
Dosage by Week 
Dose 
Week 1, BID Dosing  
Weeks 2 through 12, QD Dosing 
20 mg 
one 10-mg IW-1973 Tablet, orally twice daily 
two 10-mg IW-1973 Tablets, orally once daily 
40 mg 
one 20-mg IW-1973 Tablet, orally twice daily 
two 20-mg IW-1973 Tablets, orally once daily 
Placebo 
one matching placebo tablet, orally twice daily 
two matching placebo tablets, orally once daily 
BID=twice daily; QD=once daily 
 
3.5.1.5 
Storage and Accountability 
IW-1973 Tablet and placebo to match must be stored under refrigerated conditions, 2° to 8°C 
(36° to 46°F) at the clinical sites. Any deviation from these storage conditions must be reported 
to Ironwood, and use of the study drug suspended until re-authorization has been provided by 
Ironwood. If a temperature excursion occurs above 8°C (46°F) up to a maximum temperature of 
30°C (86°F) for not longer than 24 hours, the clinical site is authorized by Ironwood 
Pharmaceuticals to continue using the study drug after documentation of the excursion has been 
completed. If a temperature excursion occurs below 2°C or above 30°C (<36°F or >86°F) for any 
amount of time, or from 8°C to 30°C for periods longer than 24 hours, the use of the study drug 
is suspended until authorization for its continued use has been provided by Ironwood. 
Once distributed to patients, patients will be instructed to keep the bottles at room temperature 
(15°C to 30°C/59°F to 86°F). 
The Investigator must ensure that the receipt and use of all study drug supplied is recorded. All 
study drug supplies must be retained in a locked room that may only be accessed by the 
pharmacist, Investigator, or other duly designated persons. Study drug must not be used outside 
the context of this protocol, and under no circumstances should the Investigator or study center 
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personnel allow the supplies to be used other than as directed by this protocol without prior 
authorization from Ironwood. 
Study drug accountability should be performed at the medication level. Patients will be 
instructed to return all unused study drug to the study center. All returned and unused study drug 
must be retained at the site. At the end of the study, a complete reconciliation of the study drug 
supplies will be performed. A copy of the final Drug Accountability Log will be provided to 
Ironwood, or accountability will be completed electronically within the product returns module 
of an interactive response technology system when available. All unused and reconciled drug 
supplies will be returned to PCI Pharma Services or destroyed according to standard institutional 
policy or per written instruction from Ironwood should an alternate disposition be requested. No 
study drug is to be destroyed without prior written permission of Ironwood. A copy of the 
Certificate of Destruction or equivalent shall be provided to Ironwood once available.  
In addition, study drug will be dispensed to patients in bottles equipped with a MEMSCap, 
which will record the dates and times the bottle is opened and closed. 
3.5.2 
Method of Assigning Patients to Treatment Groups 
Approximately 150 patients who meet all of the inclusion criteria and none of the exclusion 
criteria will be stratified by Baseline eGFR (ie, eGFR 30 to 45, >45 to 60, and >60 to 
75 mL/min/1.73 m2) and randomized 1:1:1 to 20 mg IW-1973, 40 mg IW-1973, or placebo at the 
Randomization Visit on Day 1. 
Patients will be randomized through central randomization. The computer-generated 
randomization schedule will be prepared by an independent statistician not otherwise associated 
with the study. 
Patients and Investigators will be blinded to treatment assignments in this study (see 
Section 3.5.6 for more details on blinding in this study). 
3.5.3 
Selection of Dosage in the Study 
This Phase 2 study will evaluate 2 dose levels of oral IW-1973 administered daily for 12 weeks: 
20 mg and 40 mg. In the Phase 1b MAD study (ICP-1973-102), 40 mg IW-1973 was considered 
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adequately tolerated and produced pharmacodynamic (PD) effects (including reduced BP and 
increased plasma cGMP levels). It was therefore chosen as the high dose for evaluation in this 
patient population. For comparison to 40 mg, 20 mg IW-1973 was chosen for evaluation because 
it demonstrated pharmacodynamic effects following 2 weeks of dosing in the MAD study and 
was associated with a lower incidence of AEs. The plasma concentrations achieved in humans at 
the 20- and 40-mg dose levels were within the range associated with renal efficacy in the Dahl 
salt-sensitive rat model (reduced albuminuria, attenuated kidney weight gain, and improved renal 
histology). 
3.5.4 
Selection and Timing of Dose for Each Patient and Dose Reduction 
3.5.4.1 
Study Drug Administration 
During Week 1, all patients will take study drug BID (2×/day), 1 tablet in the morning and 
1 tablet approximately 12 hours later in the evening, preferably at approximately the same times 
each day. From Day 8 (±1) on, patients will take study drug QD (1×/day), 2 tablets in the 
morning, preferably at approximately the same time each day. Patients should take study drug 
with water, may take study drug with or without food, and, for QD dosing, may swallow tablets 
together, if desired. On study visit days, study drug will be administered in the clinic after 
predose BP/pulse measurements and blood/urine sampling (on Randomization Day, patients will 
receive only their morning dose in the clinic); therefore, study visits should be scheduled in the 
morning to accommodate patients’ regular dosing schedules. 
3.5.4.2 
Dose Reduction 
Per Investigator discretion, on a per-patient basis, dose may be reduced by half, ie, from 2 tablets 
daily to 1 tablet daily (in the morning). Each patient’s dose may only be reduced once and may 
not be increased after reduction. Investigators should notify the Medical Monitor of all decisions 
to dose reduce on a per-patient basis.  
3.5.5 
Treatment Compliance 
The appropriate amount of study drug will be dispensed to patients in prelabeled bottles at the 
Randomization, Week 1, Week 4, and Week 8 Visits. Patients will be asked to return all bottles 
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(including unused tablets) at the Week 1, Week 4, Week 8, and End of Treatment Visits for 
assessment of compliance with the dosing regimen.  
Treatment compliance will be based on count of pills. 
3.5.6 
Blinding 
This study is double blind and placebo controlled. The investigational product and placebo will 
be identical oral tablets.  
Unblinding of a patient’s treatment assignment is restricted to emergency situations and should 
only be used under circumstances where knowledge of the treatment is necessary for the proper 
handling of the patient. Except in a medical emergency, the Investigator and study center staff 
will remain blinded during the conduct of the study and until, at a minimum, all discrepancies in 
the clinical database are resolved (ie, at the time of the database lock). Individual patient 
treatment assignment unblinding is available to the Investigator through the interactive web 
response system (IWRS) in the event of an emergency. The Investigator should make all 
reasonable efforts to notify and discuss the circumstances requiring unblinding with the Medical 
Monitor or designee in advance of breaking the blind. If the treatment blind is broken, the reason 
and the date should be recorded and signed by the Investigator and information regarding the 
unblinding should be submitted as soon as possible to the Sponsor. If the Investigator is 
unblinded to the treatment assignment of a patient, the patient will be immediately withdrawn 
from study drug dosing and should follow early termination procedures (Section 3.4.3). 
The Sponsor may also break the blind in circumstances where unblinding is necessary for the 
safety of the patients. 
To allow ongoing safety monitoring during the conduct of the study, members of an external 
DMC will review summaries of AE data by treatment groups randomly masked as A, B, and C 
and may request unblinded safety data. Please refer to Section 5.13 for more details. 
 
 
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3.5.7 
Prior and Concomitant Therapy 
At the Screening Visit, the following information will be recorded for each patient: 
• All medications the patient is taking (ongoing) 
• All prior medications taken during the 30 days before the Screening Visit 
 
Beginning at the Screening Visit, any medication or change in medication taken by a patient 
during the study will be documented in the source documents and the eCRF along with the start 
and stop date and the reason for use.  
Patients will be on a stable regimen of at least 1 antihyperglycemic medication and an ACEi or 
an ARB (see Inclusion Criteria for details), which may be modified during the study if medically 
necessary. Patients may be on a stable regimen of medication(s) for hypertension, which may be 
modified during the study if medically necessary. Permitted concomitant medications should be 
taken at the same time each day and may be taken at the same time as study drug.  
Pharmacological stimulation of sGC by IW-1973 produces an increase in cGMP production. 
Concomitant administration of IW-1973 with an angiotensin receptor neprilysin inhibitor (ie, 
sacubitril/valsartan) should be allowed with caution as neprilysin inhibition results in increased 
cGMP concentrations via protection of natriuretic peptides. 
Prohibited medications and supplements are listed in Sections 3.6 and Appendix 1. 
3.6 
RESTRICTIONS 
3.6.1 
Prohibited Medicines and Supplements 
Specific inhibitors of phosphodiesterase 5 (PDE5) (including sildenafil and tadalafil), 
nonspecific inhibitors of PDE5 (including dipyridamole and theophylline), any supplements for 
the treatment of erectile dysfunction, riociguat, and nitrates or NO donors in any form are 
prohibited from 7 days before the Randomization Visit on Day 1 through the duration of the trial.  
Strong inhibitors of CYP3A are prohibited from 14 days before Randomization through the 
duration of the trial. Examples include azole antifungals, macrolide antibiotics, protease 
inhibitors, diltiazem, and concentrated grapefruit supplements. 
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See Appendix 1 for a more detailed list of prohibited medicines and supplements.  
3.6.2 
Fluid and Food Restrictions 
Patients should fast overnight (at least 8 hours) before predose blood and urine sample 
collections at all study visits, except for the Screening Visit.  
Excessive grapefruit intake is prohibited from 14 days before Randomization through the 
duration of the trial. 
Patient must agree not to make any major changes to their diet from the Screening Period 
through the Follow-up Visit. 
3.6.3 
Patient Activity  
Patient must agree not to make any major changes to their exercise routine from the Screening 
Period through the Follow-up Visit. 
3.6.3.1 
Sexual Activity and Birth Control 
Female patients who are not postmenopausal for at least 1 year (ie, 12 months of spontaneous 
amenorrhea [not induced by a medical condition or medical therapy]) or are not surgically sterile 
(ie, bilateral oophorectomy, hysterectomy, or tubal sterilization [tie, clip, band, or burn]) must 
agree to completely abstain from heterosexual intercourse or, if heterosexually active, must agree 
to use 1 of the following methods of birth control from the date she signs the ICF until 60 days 
after the final dose of study drug: 
• Progesterone implant or an intrauterine device (IUD) 
• Combination of 2 highly effective birth control methods (eg, diaphragm with spermicide plus 
a condom, condom with spermicide plus a diaphragm or cervical cap, hormonal 
contraceptive [eg, oral and transdermal patch] plus a barrier method, partner with vasectomy 
[conducted 60 days before the Screening Visit or confirmed via sperm analysis] plus a 
hormone/barrier method). 
 
Female patients must wait at least 60 days after the final dose of study drug to try to become 
pregnant and/or to undergo egg donation or egg harvesting for current or future in vitro 
fertilization. 
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Male patients who are not surgically sterile by vasectomy (conducted 60 days before the 
Screening Visit or confirmed via sperm analysis) must agree to completely abstain from 
heterosexual intercourse or, if heterosexually active, must agree to use a combination of 2 highly 
effective birth control methods (eg, condom with spermicide plus partner IUD, condom with 
spermicide plus a partner diaphragm/cervical cap, partner use of hormonal contraceptive 
[including progesterone implant] plus a barrier method, or postmenopausal partner [for 1 year] 
plus barrier method) from the Screening Visit through 60 days after the final dose of study drug. 
Male patients must refrain from sperm donation during the study through at least 60 days after 
the final dose of study drug. 
3.7 
 INDIVIDUAL STOPPING CRITERIA AND DMC REVIEWS 
If any events included in Table 3 are reported during the study and are judged to be both study 
drug related and an SAE (per causality and SAE definitions in Section 3.8.9.3), individual 
stopping criteria or DMC review will be triggered per the criteria in Sections 3.7.1 and Table 3, 
respectively. The inclusion of these AEs is based on the clinical experience with IW-1973, the 
prescribing information for riociguat, and the patient population for this study. 
Table 3. 
Categories of SAEs Triggering Individual Stopping Criteria and Safety 
Committee Review 
Treatment-emergent Study Drug-related SAE Category 
# of patients to trigger 
DMC review 
Renal failure 
(eGFR <15 mL/min/1.73 m2; dialysis or renal transplant indicated) 
2 
Spontaneous bleeding events  
(eg, hemoptysis, subarachnoid or subdural hemorrhage, hematemesis, 
hematochezia) 
2 
Symptomatic hypotension-related events  
(eg, syncope) 
2 
DMC=Data Monitoring Committee; eGFR=estimated glomerular filtration rate; SAE=serious adverse event 
 
3.7.1 
Individual Stopping Criteria 
On an individual basis, a patient will be discontinued from study drug dosing if 1 SAE from 
Table 3 is reported. At the Investigator’s or Sponsor’s discretion, any AE(s) of concern can 
likewise be the basis for patient discontinuation from the trial. 
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3.7.2 
Data Monitoring Committee Reviews  
An independent DMC comprising experts in cardiovascular and/or renal disease and/or diabetes 
and a biostatistician will review trial safety data both periodically and if SAEs from the same 
category in Table 3 are reported at the incidence indicated in the table (eg, 2 patients with 
spontaneous bleeding SAEs). After review of safety data, the DMC will recommend trial 
continuation, continuation with modification, or termination. Refer to Section 5.13 for details 
regarding the DMC, the scheduled and ad hoc reviews, the data that will be provided for review, 
and Sponsor decision-making. 
3.8 
STUDY PROCEDURES AND ASSESSMENTS 
3.8.1 
Informed Consent 
Informed consent procedures will comply with the Code of Federal Regulations (CFR) 21, 
Parts 50 and 312. 
The written ICF must be approved by the Institutional Review Board (IRB) for the purposes of 
obtaining and documenting consent. 
Before entry into the study, each patient will be provided with a written explanation of the study. 
It is the responsibility of the Investigator or appropriately trained health professional to give each 
patient full and adequate information regarding the objectives and procedures of the study and 
the possible risks involved. Patients will then be given the opportunity to ask questions and the 
Investigator will be available to answer questions as needed. Patients will be informed of their 
right to withdraw from the study at any time without prejudice. After this explanation and before 
entering the study, the patient will voluntarily sign the study-specific ICF. The patient will 
receive a copy of the signed and dated ICF. The Investigator must retain each patient’s original 
signed ICF. 
If new information becomes available that may be relevant to the patient’s consent and 
willingness to participate in the study, the ICF will be revised. The revised ICF must be 
submitted to the IRB for review and approval before its use. 
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3.8.2 
Medical History 
A complete medical history, including history of smoking, will be recorded at the Screening 
Visit. 
3.8.3 
 
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3.8.4 
Physical Examination 
A complete physical examination will be performed according to the Schedule of Events. The 
physical examination of each patient should include examination and assessment of the 
following: 
General appearance 
Head, eyes, ears, nose, and throat 
Cardiovascular system 
Neck 
Respiratory system 
Musculoskeletal system 
Abdomen/liver/spleen 
Nervous system 
Lymph nodes 
Skin 
Neurologic status 
Mental status 
 
Breast, genitourinary, and rectal examinations are optional and may be performed at the 
discretion of the Investigator. Any new, clinically significant abnormal findings from the 
physical examination will be reported as an AE. 
Each patient’s weight will be recorded at each study visit; height will only be recorded at the 
Screening Visit. 
3.8.5 
Respiratory Rate and Temperature  
Respiratory rate and oral temperature (°C) will be measured according to the Schedule of Events 
and documented on the eCRF. Respiratory rate should be measured after the patient has been 
seated for at least 5 minutes. 
3.8.6 
Hemodynamics 
Hemodynamic assessments will include seated BP and pulse, orthostatic (seated-to-standing) BP 
and pulse, and ABPM. Outside of the ABPM assessments, all other BP and pulse measurements 
will be taken by automated office blood pressure (AOBP); manual measurements are allowed in 
cases in which an AOBP machine malfunctions or is not available. 
Blood pressure and pulse measurements at the Screening and Baseline Visits will be performed 
with patients in the seated position. Seated BPs for study eligibility will be the average of 
3 measurements obtained at 2-minute intervals after the patient has been sitting quietly for at 
least 5 minutes.  
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Blood pressure and pulse measurements at the Randomization, Week 4, Week 8, End of 
Treatment, and Follow-up Visits will be seated-to-standing for calculation of orthostatic BP and 
pulse. Patients should sit quietly for at least 5 minutes before seated measurements are taken, and 
then assume a standing position for 30 to 60 seconds before standing measurements are taken. At 
the End of Treatment visit, seated predose BP will be the average of 3 measurements. 
When applicable, BP and pulse measurements should be taken before blood draws. All predose 
BP and pulse measurements should be taken before all oral and any antihypertensive 
concomitant medications. 
Patients will begin 24-hour ABPM at the study site during the Baseline and End of Treatment 
Visits and will begin 12-hour ABPM at the study site during the Week 4 and Week 8 Visits. 
Patients will return the ABPM equipment to the study site at the following study visit.  
Baseline Visit ABPM assessment: At least 65% compliance is preferred, with no more than 
10 missed readings during the day (7 am – 10 pm) and/or 3 missed readings at night (10:30 pm – 
6:30 am), and no more than 6 missed readings in succession. (If a patient’s ABPM assessment 
does not meet these criteria, the medical monitor must be contacted PRIOR to randomizing the 
patient.) 
At the Week 4, Week 8, and End of Treatment Visits, ABPM should begin before study drug 
administration. 
3.8.7 
Electrocardiograms 
A 12-lead electrocardiogram (ECG) will be performed according to the Schedule of Events and 
documented on the eCRF. Electrocardiograms should be obtained after the patient has been 
supine for at least 5 minutes. At the Screening and Baseline Visits, if on initial ECG, QTcF is 
450 msec for male patients or is 470 msec for female patients, the ECG will be repeated 
2 more times, and the average of the 3 QTcF values will be used to determine eligibility. 
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3.8.8 
Clinical Laboratory Tests 
Blood and urine samples for clinical laboratory tests will be collected according to the Schedule 
of Events. Except for the Screening Visit, patients should fast for at least 8 hours before sample 
collections. 
The clinical laboratory evaluations will include the serum chemistry, hematology (complete 
blood count [CBC]), coagulation, UA, and additional tests as presented in Table 4. 
Table 4. 
Clinical Laboratory Tests 
Serum Chemistry 
Hematology (CBC) 
Urinalysis 
Albumin 
Hematocrit 
Color and appearance 
Alkaline Phosphatase 
Hemoglobin 
pH and Specific Gravity 
ALT 
Platelet count 
Bilirubin 
AST 
MPV 
Glucose 
Bicarbonate 
RBC count 
Ketones 
BUN 
WBC count 
Leukocytes 
Calcium 
WBC differential 
Nitrites 
Chloride 
  (% & absolute): 
Occult blood 
Cholesterol 
Basophils 
Protein 
Creatinine 
Eosinophils 
Urobilinogen 
GGT 
Lymphocytes 
Microscopic  
Glucose 
Monocytes 
Including bacteria, RBCs, WBCs 
HDL-c 
Neutrophils 
per HPF if dipstick is abnormal 
LDH 
RBC indices 
 
LDL-c (calculated) 
MCH 
Additional blood tests 
Magnesium 
MCHC 
Hemoglobin A1c 
Phosphorus 
MCV 
Fasting plasma glucose 
Potassium 
RDW 
Fasting plasma insulin 
Sodium 
 
 
Total Bilirubin 
Coagulation 
Additional urine tests  
Total Protein 
aPTT 
Urine albumin & creatinine for UACR* 
Triglycerides 
Prothrombin time 
Urine cotinine  
Uric acid 
INR 
 
ALT=alanine aminotransferase; aPTT=activated partial thromboplastin time; AST=aspartate aminotransferase; 
BUN=blood urea nitrogen; CBC=complete blood count; GGT=gamma glutamyl transferase; HPF=high power 
field; INR=International Normalized Ratio; LDH=lactate dehydrogenase; MCH=mean corpuscular hemoglobin; 
MCHC=mean corpuscular hemoglobin concentration; MCV=mean corpuscular volume; MPV=mean platelet 
volume; RBC=red blood cell; RDW=red blood cell distribution width; UACR=urine albumin-creatinine ratio; 
WBC=white blood cell.  
 
* At the Screening Visit, a single urine sample, which may not be first void, may be collected. Thereafter, 
samples should be 2 first-void urine samples collected on the 2 consecutive mornings before each scheduled 
study visit. Patients will be supplied with specimen collection supplies at the preceding study visit. 
 
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3.8.8.1 
Pregnancy Tests 
For female patients, a negative pregnancy test (by urine dipstick) must be documented at all 
study visits with results available before dosing, where applicable. In the event of a positive 
pregnancy test, the test will be repeated. If pregnancy is confirmed, see Section 3.8.9.5. Female 
patients who are postmenopausal (no menses for 12 consecutive months) or surgically sterile 
(ie, bilateral oophorectomy, hysterectomy, or tubal sterilization [tie, clip, band, or burn]) do not 
have to have a urine pregnancy test. 
3.8.8.2 
Hepatitis, HIV, and Drug Screens 
Screens for a hepatitis panel (including HBsAg and anti-HCV) and human immunodeficiency 
virus (HIV) antibody will be performed at the Screening Visit. 
A urine drug screen for the following drugs of abuse will be performed at the Screening Visit: 
Amphetamines 
Cocaine 
Phencyclidine (PCP) 
Barbiturates 
Marijuana 
Propoxyphene 
Benzodiazepines 
Opiates 
 
 
3.8.8.3 
Urine Albumin Creatinine Ratio (UACR) 
UACR will be calculated as urine albumin (mg/dL) / urine creatinine (g/dL).  
Urine albumin and urine creatinine levels will be determined as part of the clinical laboratory 
tests (Table 4). At the Screening Visit, a single urine sample, which may not be first void, will be 
collected for determination of albumin and creatinine levels. For subsequent study visits, patients 
will be given urine collection supplies and will collect 2 first-void urine samples on the 
2 consecutive mornings before each scheduled visit.  
3.8.8.4 
Estimated Glomerular Filtration Rate (eGFR) 
Estimated glomerular filtration rate will be based on the serum creatinine level determined as 
part of the clinical laboratory tests (Table 4) and will be calculated according to the Chronic 
Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation.(1)  
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The CKD-EPI equation, expressed as a single equation, is  
GFR= 141 × min(Scr/ț, 1)Į × max(Scr/ț, 1) -1 209 × 0.993Age × 1.018 [if female] _ 1.159 [if black], 
 
where Scr is serum creatinine, ț is 0.7 for females and 0.9 for males, Į is -0.329 for females and 
-0.411 for males, min indicates the minimum of Scr/țor 1, and max indicates the maximum of 
Scr/ț or 1. 
3.8.8.5 
HOMA-IR 
Blood samples for determination of fasting plasma glucose and insulin levels will be collected 
according to the Schedule of Events. Values will be used in the Homeostatic Model Assessment 
to estimate insulin resistance (HOMA-IR).(34,35)  
The HOMA-IR equation is:  
HOMA-IR = (FPI × FPG)/22.5, 
where FPI is fasting plasma insulin concentration (mU/L) and FPG is fasting plasma glucose 
(mmol/L). 
3.8.9 
Adverse Events  
All patients will be monitored for AEs throughout the study. All AEs will be recorded in 
accordance with the procedures outlined in this section. 
An AE is any untoward medical occurrence in a patient or clinical investigation subject 
administered a pharmaceutical product and which does not necessarily have to have a causal 
relationship with this treatment.  
An AE, therefore, can be any unfavorable and unintended sign (including an abnormal laboratory 
finding, for example), symptom, or disease temporally associated with the use of a medicinal 
product, whether or not considered related to the medicinal product. 
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An AE includes, but is not limited to, the following: 
• Any unfavorable changes in general condition 
• Any clinically significant worsening of a preexisting condition 
• Any intercurrent diseases and accidents 
 
Note: A procedure is not an AE, but the reason for a procedure may be an AE. 
3.8.9.1 
Causality Assessment 
For all AEs, the Investigator must provide an assessment of causal relationship to study drug. 
The causality assessment must be recorded in the patient’s source documentation and on the AE 
page of the subject’s eCRF. Causal relationship must be assessed according to the following: 
Related:  
An event where there is a reasonable possibility of a causal relationship between 
the event and the study drug 
Unrelated:  
Any other event 
3.8.9.2 
Severity Assessment 
The Investigator will provide an assessment of the severity of each AE by recording a severity 
rating in the patient’s source documentation and on the AE page of the patient’s eCRF. Severity, 
which is a description of the intensity of manifestation of the AE, is distinct from seriousness, 
which implies a patient outcome or AE-required treatment measure associated with a threat to 
life or functionality. Severity will be assessed according to the following scale: 
Mild: 
A type of AE that is usually transient and may require only minimal treatment or 
therapeutic intervention. The event does not generally interfere with usual 
activities of daily living. 
Moderate: 
A type of AE that is usually alleviated with additional specific therapeutic 
intervention. The event interferes with usual activities of daily living, causing 
discomfort but poses no significant or permanent risk of harm to the research 
participant. 
Severe: 
A type of AE that interrupts usual activities of daily living, or significantly affects 
clinical status, or may require intensive therapeutic intervention. 
 
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3.8.9.3 
Serious Adverse Events 
An SAE is defined as any AE occurring at any dose that results in any of the following 
outcomes: 
• Death 
• Life-threatening: the patient was at immediate risk of death from the reaction as it occurred 
(ie, it does not include a reaction that hypothetically might have caused death if it had 
occurred in a more severe form) 
• Hospitalization or prolongation of existing hospitalization 
• Persistent or significant disability/incapacity: a substantial disruption of a person’s ability to 
conduct normal daily functions 
• Congenital anomaly/birth defect 
• Important medical events: events that may not result in death, be life threatening, or require 
hospitalization. Such an event may be considered serious when, based on appropriate medical 
judgment, it may jeopardize the subject and may require medical or surgical intervention to 
prevent 1 of the outcomes listed in this definition. Examples of such medical events include 
allergic bronchospasm requiring intensive treatment in an emergency department or at home, 
blood dyscrasias or convulsions that do not result in inpatient hospitalization, or the 
development of drug dependency or drug abuse. 
 
Emergency room visits that do not result in admission to the hospital should be evaluated for 1 of 
the other serious outcomes (eg, life-threatening, other serious [medically important] event). 
3.8.9.4 
Recording Adverse Events 
Adverse events will be collected and recorded from the time the patient signs the ICF at the 
Screening Visit through the Follow-up Visit. All AEs, regardless of the assumption of a causal 
relationship with study procedures or study medication, must be recorded in the patient’s source 
documentation and subsequently on the appropriate AE page of the patient’s eCRF. This record 
includes AEs the patient reports spontaneously, those observed by the Investigator, and those 
elicited by the Investigator in response to open-ended questions during the study, such as “Have 
you had any health problems since your last visit?” 
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For every AE, the Investigator must: 
• Provide an assessment of the severity, causal relationship to the study medication, and 
seriousness of the event 
• Document all actions taken with regard to the study medication (ie, no action taken, 
treatment temporarily interrupted, or treatment discontinued)  
• Detail any other treatment measures taken for the AE, including concomitant medications 
and/or procedures 
 
Pretreatment AEs will be collected from the time the patient signs the ICF until the patient 
receives study drug. Pretreatment AEs will be captured in the patient’s source documentation but 
will only be entered for randomized patients on the AE page of the patient’s eCRF. 
Laboratory abnormalities and changes in vital signs, physical examination findings, and 12-lead 
ECG parameters should be considered AEs and reported on the AE page of the patient’s eCRF if 
the Investigator considers them clinically significant and/or they necessitate intervention. 
Any medical condition that is present when a patient is screened and does not worsen in severity 
and/or frequency should be reported as Medical History and not as an AE. However, if the 
condition does deteriorate in severity and/or frequency at any time during the study, it should be 
reported as an AE. 
3.8.9.5 
Reporting Serious Adverse Events and Pregnancy 
An AE that meets any of the serious criteria must be reported to Covance within 24 hours from 
the time that site personnel first learn of the event, using the SAE Report form provided for the 
study. All SAEs must be recorded in the subject’s source documentation and, subsequently, on 
the appropriate AE reporting page of the subject’s eCRF, whether or not they are considered 
causally related to study medication.  
Regardless of causality, all SAEs must be recorded and reported from the time the patient signs 
the ICF at the Screening Visit until the final Follow-up Visit. Any SAE that occurs at any time 
after the specified follow-up period and which the Investigator considers study drug related 
should be reported immediately. 
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The initial SAE report should include the following information at minimum: 
• Patient identification number 
• Description and onset of the event 
• Serious criteria 
• Causality assessment to study drug 
 
All SAE and pregnancy information should be emailed to Covance as shown below. 
All SAE and Pregnancy Report Forms should be emailed or faxed to: 
 
or 
Fax#: 
 
If follow-up is obtained, or is requested by Covance, the additional information should be 
emailed on an SAE or Pregnancy Report Form to Covance, in a timely manner according to the 
procedures outlined above. Copies of discharge summaries, consultant reports, autopsy reports, 
and any other relevant documents may also be requested. 
Appropriate remedial measures should be taken by the Investigator using his/her best medical 
judgment to treat the SAE. These measures and the subject’s response to these measures should 
be recorded. All SAEs regardless of relationship to study drug will be followed by the 
Investigator until satisfactory resolution, until the Investigator deems the SAE to be chronic or 
stable, or until the subject is lost to follow-up. Clinical, laboratory, and diagnostic measures 
 
In the event that a pregnancy occurs in a patient, study drug must be stopped at once and study 
personnel must report the pregnancy within 24 hours from the time that site personnel first learn 
of the pregnancy using the pregnancy notification form provided for this study. Study personnel 
must also make every reasonable effort to follow the pregnancy until resolution and report the 
outcome using the pregnancy outcome form provided for this study. If the pregnancy is 
associated with an SAE (eg, if the mother is hospitalized), a separate SAE form must be 
submitted. 
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should be employed by the Investigator as needed to adequately determine the etiology of the 
event. 
The Investigator will be responsible for reporting all SAEs to the IRB. Ironwood will be 
responsible for reporting to the regulatory authorities. 
3.8.10 
  
 
 
  
3.8.11 
 
 
 
 
 
 
 
 
 
 
3.8.12 
Pharmacokinetic Assessments 
Blood samples for PK assessments will be collected according to the Schedule of Events.  
3.8.13 
  
 
 
 
  
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3.9 
STUDY ACTIVITIES 
3.9.1 
Screening Period (Day -45 to Day -1) 
3.9.1.1 
Screening Visit (Days -45 to -15) 
• Obtain informed consent  
• Record demographics and medical history 
• Review inclusion and exclusion criteria 
• Review prior and concomitant medications (all medicines taken during the 30 days before the 
Screening Visit) 
• 
 
• Record weight and height 
• Perform physical examination 
• Perform 12-lead ECG (if QTcF exceeds eligibility criterion, conduct 2 more ECGs and use 
average of 3 values for determination of eligibility) 
• Record respiratory rate and oral temperature 
• Record seated BP (average of 3 measurements) and pulse  
• Collect blood and urine samples for: 
- 
Serum chemistry, hematology (CBC), coagulation 
- 
Urinalysis (may be collected at any time during study visit) 
- 
Urine albumin and creatinine (may be collected at any time during study visit) 
- 
Urine pregnancy test, as applicable (must be confirmed negative) (may be collected at 
any time during study visit) 
- 
Hemoglobin A1c 
- 
Urine drug screen (may be collected at any time during study visit) 
- 
HBsAg, HCV, and HIV screen 
• Conduct AE evaluation 
• Issue supplies and instructions for first-void urine sampling 
 
Note: Screening Visit assessments may take place over more than 1 day. Patients may be 
rescreened should they discontinue in the Screening Period due to visit window deviations or 
other administrative reasons. In addition, laboratory values, ECG values, or BPs that are outside 
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the range specified in the protocol may be repeated to confirm eligibility during the Screening 
Period at the Investigator’s discretion after consultation with the Medical Monitor. 
3.9.1.2 
Baseline Visit (Days –7 ±3) 
• Return by patient:  
- 
2 first-void urine samples  
• Review inclusion and exclusion criteria 
• Review prior and current medications  
• Record weight 
• Perform 12-lead ECG (if QTcF exceeds eligibility criterion, conduct 2 more ECGs and use 
average of 3 values for determination of eligibility) 
• Record seated BP (average of 3 measurements) and pulse  
• Begin ABPM; patient will wear 24 hours and should return monitor to clinic at next study 
visit 
• Collect blood and urine samples for: 
- 
Serum chemistry, hematology (CBC), coagulation 
- 
Urinalysis (may be collected at any time during study visit) 
- 
Urine pregnancy test, as applicable (must be confirmed negative; may be collected at any 
time during study visit) 
- 
Hemoglobin A1c 
- 
Fasting plasma glucose and insulin 
• Conduct AE evaluation 
• Issue supplies and instructions for first-void urine sampling 
 
3.9.2 
Treatment Period (Day 1 to Day 87 ±3) 
3.9.2.1 
Randomization Visit (Day 1) 
• Return by patient:  
- 
2 first-void urine samples  
- 
ABPM cuff and monitor (may be returned outside of study visit) 
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•
Collect predose urine samples for:
-
Pregnancy test, as applicable (must be confirmed negative before randomization)
-
Urine cotinine
-
•
Confirm inclusion and exclusion criteria
•
Review prior and concomitant medications
•
Record weight
•
•
Record respiratory rate and oral temperature predose (30 minutes)
•
Record seated-to-standing (orthostatic) pulse and BP predose (30 minutes)
•
Collect predose (30 minutes) blood samples for:
-
Serum creatinine and glucose
-
-
PK
-
-
•
Randomize patient
•
Dispense study drug
•
MEMS introduction
•
Administer study drug (morning dose)
•
Record respiratory rate and oral temperature at 1 hour (±15 minutes) postdose
•
Record seated-to-standing (orthostatic) pulse and BP at 1, 2, 4, and 6 hours (±15 m) postdose
•
Collect blood samples for PK at 1, 3, and 6 hours (±15 minutes) postdose
•
Conduct AE evaluation
•
Issue supplies and instructions for first-void urine sampling
3.9.2.2 
Week 1 Visit (Day 8 ±1) 
•
Return by patient:
-
2 first-void urine samples
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- 
Study drug (Patients will bring in study drug dispensed on Day 1. MEMS Caps will be 
read, and the subject will be administered the Day 8 [±1] study drug dose in the clinic 
from the Day 1 bottles. The subject will continue to dose from the Day 1 bottles until 
returning for the Week 4 Visit.) 
• Collect predose urine samples for pregnancy test, as applicable  
• Record concomitant medications 
• Record weight 
• Record respiratory rate and oral temperature predose (30 minutes)  
• Record seated-to-standing (orthostatic) pulse and BP predose (30 minutes)  
• Collect predose (30 minutes) blood samples for: 
- 
Serum creatinine and glucose  
- 
Hemoglobin A1c 
- 
Fasting plasma glucose and insulin 
- 
 
- 
PK  
• Review MEMS cap data 
• Administer study drug 
• Record respiratory rate and oral temperature at 1 hour (±15 minutes) postdose 
• Record seated-to-standing (orthostatic) pulse and BP at 1, 2, 4 and 6 hours (±15 minutes) 
postdose 
• Collect blood samples for PK at 1, 3, and 6 hours (±15 minutes) postdose 
• 
 
• Conduct AE evaluation 
• Issue supplies and instructions for first-void urine sampling 
 
3.9.2.3 
Week 4 Visit (Day 29 ±3) 
• Return by patient:  
- 
2 first-void urine samples 
- 
Study drug  
• Collect predose urine sample for pregnancy test, as applicable  
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• Record concomitant medications 
• Record weight 
• 
 
• Record seated-to-standing (orthostatic) pulse and BP predose (30 minutes)  
• Begin ABPM; patient will wear 12 hours and should return monitor at next study visit 
• Collect predose (30 minutes) blood samples for: 
- 
Serum chemistry, hematology (CBC), coagulation  
- 
Hemoglobin A1c 
- 
Fasting plasma glucose and insulin 
- 
PK  
• Review MEMS cap data 
• Dispense study drug  
• Administer study drug 
• Conduct AE evaluation 
• Issue supplies and instructions for first-void urine sampling 
 
3.9.2.4 
Week 8 Visit (Day 57 ±3) 
• Return by patient:  
- 
2 first-void urine samples  
- 
ABPM cuff and monitor (may be returned outside of study visit) 
- 
Study drug 
• Collect predose urine samples for pregnancy test, as applicable  
• Record concomitant medications 
• Record weight 
• 
 
• Record seated-to-standing (orthostatic) pulse and BP predose (30 minutes)  
• Begin ABPM; patient will wear 12 hours and should return monitor to clinic at next study 
visit 
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•
Collect predose (30 minutes) blood samples for:
-
Serum creatinine and glucose
-
Hemoglobin A1c
-
Fasting plasma glucose and insulin
-
PK
•
Review MEMS cap data
•
Dispense study drug
•
Administer study drug
•
Conduct AE evaluation
•
Issue supplies and instructions for first-void urine sampling
3.9.2.5 
End of Treatment Visit (Day 87 ±3) 
•
Return by patient:
-
2 first-void urine samples
-
ABPM cuff and monitor (may be returned outside of study visit)
-
Study drug
•
Collect predose urine samples for:
-
Pregnancy test, as applicable
-
Urinalysis
-
•
Record concomitant medications
•
Record weight
•
Perform physical examination
•
•
Record respiratory rate and oral temperature
•
Perform 12-lead ECG
•
Record seated-to-standing (orthostatic) pulse and BP predose (30 minutes) (seated
measurement will be the average of 3 measurements)
•
Begin ABPM; patient will wear 24 hours and should return monitor to clinic at next study
visit
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•
Collect predose (30 minutes) blood samples for:
-
Serum chemistry, hematology (CBC), coagulation
-
Hemoglobin A1c
-
Fasting plasma glucose and insulin
-
-
PK
-
•
Administer study drug
•
Collect blood sample for PK at 3 hours (±15 minutes) postdose
•
Conduct AE evaluation
•
Issue supplies and instructions for first-void urine sampling
3.9.3 
Follow-up Period (Day 87 ±3 to Day 115 ±3) 
3.9.3.1 
Follow-up Visit (Day 115 ±3)  
•
Return by patient:
-
2 first-void urine samples
-
ABPM cuff and monitor (may be returned outside of study visit)
•
Record concomitant medications
•
Record weight
•
•
Record respiratory rate and oral temperature
•
Record seated-to-standing (orthostatic) pulse and BP
•
Collect blood and urine samples for:
-
Urine pregnancy test, as applicable
-
Serum chemistry, hematology (CBC), coagulation
-
Hemoglobin A1c
-
Urinalysis
-
PK
-
•
Conduct AE evaluation
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4.
STUDY ENDPOINTS
4.1 
PRIMARY ENDPOINTS
4.1.1 
Primary Safety
•
Incidence of TEAEs and study drug-related TEAEs
4.1.2 
Primary Efficacy 
•
Change from baseline in UACR over Weeks 8 and 12
4.2 
EXPLORATORY ENDPOINTS 
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5. 
STATISTICAL METHODS 
5.1 
GENERAL CONSIDERATIONS 
Descriptive statistics (n, mean or geometric mean, standard deviation, coefficient of variation, 
minimum, median, maximum, 25th and 75th percentiles) will be calculated to summarize 
continuous variables. Frequency and percentage of patients in each category will be calculated to 
summarize categorical variables. Additional details regarding the statistical methods will be 
provided in the Statistical Analysis Plan (SAP), to be finalized before unblinding of the study. 
5.2 
DETERMINATION OF SAMPLE SIZE 
Using an estimate of standard deviation of 0.67, (29) a sample size of 40 patients per treatment 
group would provide approximately 80% power to detect a mean between-group difference 
of -0.376 units in change from baseline in log-transformed UACR over 12 weeks, with a one-
sided significance level of 0.05 for at least 1 dose versus placebo comparison. This difference 
corresponds to a 31% between-group reduction of geometric mean change from baseline in 
UACR. Assuming a drop-out rate of 20%, approximately 150 patients will be randomly assigned 
in a 1:1:1 ratio (approximately 50 patients per treatment group) to 20 mg IW-1973, 40 mg 
IW-1973, or placebo. 
5.3 
ANALYSIS POPULATIONS 
The following populations will be defined for this study: 
• Safety Population: The Safety Population will consist of all randomized patients who 
receive at least 1 dose of study drug. Patients in this population will be summarized 
according to the treatment they actually received. 
• Intent-to-Treat (ITT) Population: The ITT Population will consist of all randomized 
patients who receive at least 1 dose of study drug. Patients in this population will be 
evaluated according to the treatment group they were assigned to at Randomization. 
• PK Population: The PK Population will consist of all randomized patients who receive at 
least 1 dose of study drug and have at least 1 postdose PK parameter assessment. 
• Per-Protocol (PP) Population: The PP Population will consist of all ITT patients who did 
not have any major protocol deviations or dose reduction. 
 
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5.4 
PATIENT DISPOSITION 
The total number of screened patients and the number of patients who are screen failures will be 
tabulated. The number of patients who were randomized and the number and percentage of 
patients included in each population will be presented by treatment group. The number and 
percentage of patients who completed the study or discontinued early, as well as the reasons for 
discontinuation, will be presented by treatment group.  
5.5 
DEMOGRAPHICS AND BASELINE CHARACTERISTICS 
Demographic parameters (eg, age, sex, race, ethnicity, weight, height, body mass index [BMI]) 
and other baseline characteristics will be summarized by treatment group for the Safety and 
ITT Populations.  
The number and percentage of patients with abnormalities in medical and surgical histories in 
each system organ class (SOC) and preferred term (PT) will be summarized by treatment group 
for the Safety Population. 
5.6 
DRUG EXPOSURE AND COMPLIANCE 
Exposure to study drug, calculated as the number of days from the first dose taken to the date of 
the last dose taken, inclusive, will be summarized by treatment group for the ITT Population. 
The total number of doses taken between each scheduled visit and overall for the entire study 
will be calculated for each subject. Compliance will be based on the number of doses expected to 
be taken. Percent compliance for study medication will be summarized by treatment group and 
overall for the ITT Population. Compliance rates will also be categorized as missing, <80%, 
80% and 120%, and >120% and summarized by treatment group.  
5.7 
PRIOR AND CONCOMITANT MEDICATIONS 
Prior medicines are defined as any medicines taken before the date of first dose of study drug. 
Concomitant medicines are defined as any medicines taken on or after the date of first dose of 
study drug. Any medicines taken after the date of last dose of study drug will not be considered 
concomitant medicines. Both prior and concomitant medicine use will be summarized by the 
number and percentage of patients in each treatment group receiving each medicine within each 
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therapeutic class for the ITT Population. Multiple medicines used by a patient in the same 
category (based on Anatomical-Therapeutic-Chemical classification) will only be counted once. 
5.8 
MAJOR PROTOCOL DEVIATIONS 
Major protocol deviations will be identified and documented based on a review of protocol 
deviations before database lock and treatment unblinding, and will be used to define the 
PP population. The categories of major protocol deviations to be reviewed include, but are not 
limited to, patients who: 
• Did not meet key inclusion/exclusion criteria 
• Received disallowed concomitant medication that could meaningfully impact results 
• Had overall treatment compliance rate <80% or >120% 
 
The number and percentage of subjects with major protocol deviations will be summarized by 
type of deviation and by treatment group for the ITT Population. All major protocol deviations 
will be presented in a data listing. 
5.9 
EFFICACY ANALYSES 
All efficacy analyses will be based on the ITT and PP Populations. 
Corresponding with the primary efficacy objective of the trial, the primary inference for 
hypothesis testing is the treatment difference between the placebo group and the IW-1973 groups 
on the change from baseline in log UACR over Weeks 8 and 12. The primary efficacy analysis 
will be conducted using the ITT population using a mixed-effects model repeated measures 
(MMRM) analysis with change from baseline in log-transformed UACR as the response 
variable, treatment, site, visit, treatment-by-visit interaction, and baseline eGFR stratum as fixed 
effects, and baseline log UACR and baseline MAP as covariates with unstructured as the 
variance-covariance structure. Treatment differences between the pooled IW-1973 dose groups 
and the placebo group will be estimated overall. The null hypothesis of the test will be 
interpreted as equality between the placebo and pooled treatment groups, and rejection of the 
null hypothesis as evidence that the pooled IW-1973 groups have a greater effect on lowering 
UACR than the placebo group. If the null hypothesis is rejected, the nature of these differences 
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will be explored further by estimating the treatment differences between each IW-1973 dose 
group and the placebo group overall and at each assessment timepoint. Least square (LS) means, 
and LS mean differences between each IW-1973 group and placebo, and their associated one-
sided 95% confidence intervals will be calculated overall and for each assessment timepoint. The 
contrasts between each IW-1973 dose group and the placebo group at each assessment timepoint 
will be compared using a one-sided significance level of 0.05. If the treatment-by-visit 
interaction is significant at the 0.1 significance level, LS mean treatment differences relative to 
the previous visit will also be presented.  
All change-from-baseline efficacy parameters will use the same MMRM model.  
Treatment group differences in the proportion of patients who achieved a 30% or 40% reduction 
in UACR from baseline to Week 12 will be analyzed using Cochran-Mantel-Haenszel (CMH) 
test stratified by baseline eGFR stratum. 
Summary statistics will be presented by treatment group for the biomarker parameters. Change 
from baseline in these variables will also be presented, where applicable. 
5.9.1 
Controlling for Multiplicity 
No adjustments will be made for multiple comparisons. 
5.10 
SAFETY ANALYSES 
All safety parameters will be analyzed descriptively for the Safety Population. 
5.10.1 
Adverse Events 
Adverse events will be coded using the latest version of Medical Dictionary for Regulatory 
Activities (MedDRA) available at the start of the study. Treatment-emergent adverse events 
(TEAEs) are those AEs that started or worsened in severity after the administration of study 
drug. TEAEs will be summarized for each treatment group by SOC and PT; PT and severity, by 
SOC; PT and relationship to study drug; and by SOC, PT, and baseline eGFR. If a patient has 
more than 1 TEAE coded to the same preferred term, the patient will be counted only once for 
that preferred term by identifying those TEAEs with the highest severity and the closest 
relationship to study drug.  
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In addition, the incidence of AEs leading to premature discontinuation of study drug will be 
summarized by treatment group. Listings of pretreatment AEs, TEAEs, severe TEAEs, study 
drug-related AEs, SAEs, AEs leading to study discontinuation, and AEs leading to death (if any) 
will be provided. 
5.10.2 
Clinical Laboratory Parameters 
Descriptive statistics for clinical laboratory values (in standard units) and changes from the 
baseline values at each assessment time point will be presented by treatment group for each 
clinical laboratory parameter. 
5.10.3 
Vital Signs 
Descriptive statistics for vital signs (ie, pulse rate, systolic and diastolic BP, respiratory rate, 
temperature, and body weight) and changes from baseline values at each visit will be presented 
by treatment group for the Safety Population. 
5.10.4 
ECGs 
Descriptive statistics for ECG parameters and changes from the baseline values at the end of 
treatment visit will be presented by treatment group for the Safety Population. 
The number and percentage of patients with ECG abnormalities will be tabulated by treatment 
group. A listing of all AEs for patients with ECG abnormalities will also be provided. 
5.10.5 
  
 
 
 
 
 
 
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5.11 
PK 
 
All PK analyses will be based on the PK Population. Descriptive statistics will be presented for 
IW-1973 plasma concentrations at each assessed timepoint.  
 
 
 
 
 
5.12 
 
 
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5.13 
DATA MONITORING COMMITTEE  
An independent DMC will be given the responsibility to review trial safety and provide guidance 
consistent with the objectives of the study and appropriate ethical requirements.  
The DMC will comprise experts in cardiovascular and/or renal disease, diabetes, and 
biostatistics, who have experience in clinical trials and are not involved in the conduct of this 
trial. Their only role in this study will be as a member of the DMC, thus ensuring their 
independent review of safety data.  
Three safety review meetings will be scheduled: the first after 30 patients have been randomized, 
or 5 months after the first subject is randomized (whichever is earlier); the second after 
approximately 1/3 of patients have completed or discontinued treatment; and the third after 
approximately 2/3 of patients have completed or discontinued treatment. 
For these periodic reviews, the DMC will be provided with summaries of all available AE and 
blood pressure data by treatment groups randomly masked as A, B, and C. An independent 
statistician will be responsible for summarizing and submitting these safety data to members of 
the DMC. All data presentations for the DMC will be performed using the Safety Population. If a 
safety/tolerability signal or concerning AE imbalance is identified at a review, the committee can 
request unblinding of the masked treatment groups as well as additional safety data. At each 
meeting, the DMC will review accumulated AE data and recommend trial continuation, 
modification, or termination. The DMC will also be required to perform an ad hoc review if 2 or 
more study drug-related SAEs from 1 category in Table 3 are reported. In this circumstance, the 
committee will be provided with narrative descriptions and all relevant clinical supporting 
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documentation related to the SAEs. Upon request, the unblinded treatment and dose the subjects 
received will be provided to the committee.  
In addition to the periodic and ad hoc reviews, during the trial, committee members will be 
provided with blinded reports on all SAEs.  
The DMC or the Sponsor may request ad hoc meetings at any time and at their discretion. 
There are no predefined stopping rules for the trial (for individual stopping rules, see 
Section 3.7.1). However, the DMC will be reviewing safety data as described above. The 
Sponsor, upon the recommendation of the DMC, may stop the study at any time for significant 
safety concerns. If the DMC recommends stopping or modifying the trial, a senior review team 
from the Sponsor will have the opportunity to review the blinded data and discuss study findings 
with the DMC. The senior review team will be separate from the study project teams. The 
Sponsor may also seek input from relevant regulatory authorities. The Sponsor will make the 
final decision on the recommendation and will relay its decision to the DMC and relevant 
regulatory authorities. Additional details will be provided in the DMC charter, which will be 
developed in collaboration with the DMC members and will be finalized before trial initiation. 
5.14 
INTERIM ANALYSIS (OPTIONAL) 
After at least one half of the subjects (N75) have completed the last visit, an interim analysis to 
review unblinded efficacy data may be performed to assist with the planning of future studies. If 
performed, details regarding the interim analysis will be included in the SAP, along with updates 
to the data management plan as necessary. The independent statistician (who will not be 
involved in study data collection or interpretation) performing the interim analysis and Ironwood 
staff members, as identified in the SAP, may be unblinded. DMC reviews of safety data will be 
independent of this possible interim analysis of efficacy.  
5.15 
CHANGES IN THE CONDUCT OF THE STUDY OR PLANNED 
ANALYSES 
Any amendment to this protocol will be provided to the Investigator in writing by Ironwood or 
its designee. Before implementation, any protocol amendment regarding reportable deviations 
(as defined by the IRB) must be approved by the IRB and the signature page must be signed by 
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the Investigator and received by Ironwood or its designee, with the following exception: If the 
protocol is amended to eliminate or reduce the risk to patients, the amendment may be 
implemented before IRB review and approval. However, the IRB must be informed in writing of 
such an amendment, and approval must be obtained within reasonable time limits. 
Deviating from the protocol is permitted only if absolutely necessary for the safety of the 
patients and must immediately be reported to Ironwood or its designee. 
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6. 
ETHICAL CONSIDERATIONS 
6.1 
INSTITUTIONAL REVIEW BOARD 
Before study onset, the protocol, any protocol amendments, ICFs, advertisements to be used for 
patient recruitment, and any other written information regarding this study to be provided to a 
patient or patient’s legal guardian must be approved by the IRB. 
All IRB approvals must be dated and signed by the IRB Chair or his or her designee and must 
identify the IRB by name and address, the clinical protocol by title and/or protocol number, and 
the date upon which approval or favorable opinion was granted for the clinical research. Copies 
of IRB approvals should be forwarded to Ironwood. All correspondence with the IRB should be 
maintained in the Investigator File. 
No drug will be released to the site to dose a patient until written IRB approval has been received 
by Ironwood. 
The Investigator is responsible for obtaining continuing review of the clinical research at least 
annually or more often if specified by the IRB. The Investigator must supply Ironwood with 
written documentation of the approval of the continued clinical research. 
The IRB must be constituted in accordance with Federal and International Conference on 
Harmonization (ICH) Good Clinical Practice (GCP) guidelines and any relevant and applicable 
local regulations. 
Major changes in this research activity, except those to remove an apparent immediate hazard to 
the patient, must be reviewed and approved by Ironwood and by the IRB that approved the study. 
Amendments to the protocol must be submitted in writing to the Investigator’s IRB for approval 
before patients being enrolled into the amended protocol. 
6.2 
PATIENT INFORMATION AND INFORMED CONSENT 
Informed consent procedures will comply with the Code of Federal Regulations (CFR) 21, 
Parts 50 and 312. 
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The written ICF must be approved by the IRB for the purposes of obtaining and documenting 
consent. 
Before entry into the study, each patient will be provided with a written explanation of the study. 
It is the responsibility of the Investigator or appropriately trained health professional to give each 
patient full and adequate information regarding the objectives and procedures of the study and 
the possible risks involved. Patients will then be given the opportunity to ask questions and the 
Investigator will be available to answer questions as needed. Patients will be informed of their 
right to withdraw from the study at any time without prejudice. After this explanation and before 
entering the study, the patient will voluntarily sign an ICF. The patient will receive a copy of the 
signed and dated ICF. The Investigator must retain each patient’s original signed ICF. 
If new information becomes available that may be relevant to the patient’s consent and 
willingness to participate in the study, the ICF will be revised. The revised ICF must be 
submitted to the IRB for review and approval before its use. 
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7. 
INVESTIGATORS AND STUDY ADMINISTRATIVE 
STRUCTURE 
This study will be performed at multiple study sites in the US. The Investigator at the study site 
will be responsible for ensuring that the study is conducted according to the signed Clinical Trial 
Agreement, the protocol, IRB requirements, and ICH GCP guidelines. 
The Investigator will be responsible for the oversight of the site’s conduct of the study, which 
will consist of completing all protocol assessments, maintaining the study file and the patient 
records, drug accountability, corresponding with the IRB, and completing the eCRF. 
7.1 
GENERATION OF STUDY RECORDS 
Ironwood or its designated representative will conduct a study site visit to verify the 
qualifications of each Investigator, inspect study site facilities, and inform the Investigator of 
responsibilities and procedures for ensuring adequate and correct study documentation. 
The Investigator is required to prepare and maintain adequate and accurate case histories 
designed to record all observations and other data pertinent to the study for each study patient. 
All information recorded in the eCRFs for this study must be consistent with the patient’s source 
documentation. 
During the course of the study, the Clinical Site Monitor will make study site visits to review 
protocol compliance, compare eCRFs and individual patient’s medical records, assess drug 
accountability (in a blinded manner), and ensure that the study is being conducted according to 
pertinent regulatory requirements. All eCRFs will be verified with source documentation. The 
review of medical records will be performed in a manner that ensures patient confidentiality is 
maintained. 
The Clinical Site Monitor will discuss instances of missing or uninterpretable data with the 
Investigator for resolution. Any changes to the study data will be made to the eCRF and 
documented via an electronic audit trail associated with the affected eCRF. 
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7.2 
DATA QUALITY ASSURANCE 
Ironwood performs quality control and assurance checks on all of its clinical studies. Section 7.4 
provides details regarding study monitoring procedures. 
The study may be subject to audit by Ironwood, its representatives, or regulatory authorities. In 
the event of an audit, the Investigator must agree to allow Ironwood, representatives of 
Ironwood, or the Food and Drug Administration (FDA) or other regulatory agencies access to all 
study records. 
7.3 
ELECTRONIC CASE REPORT FORMS AND DATA MANAGEMENT 
All data relating to the study will be recorded in the patient’s source documentation and eCRF to 
be provided by Ironwood or designee via the electronic data capture (EDC) system. Source 
documentation supporting the eCRF data should indicate the patient’s participation in the study 
and should document the dates and details of study procedures, AEs, all observations, and patient 
status. The Investigator is responsible for verifying that all data entries on the eCRFs are accurate 
and correct and ensuring that all data are entered in a timely manner, as soon as possible after the 
information is collected. An explanation should be provided for any missing data. The 
Investigator must provide through the EDC system his or her formal approval of all the 
information in the eCRFs and changes to the eCRFs to endorse the final submitted data for each 
patient. 
Ironwood will retain the final eCRF data and corresponding audit trails. A copy of the final 
archival eCRF in the form of a compact disc or other electronic media will be placed in the 
Investigator’s study file. 
A record of screen failures and pretreatment failures will be maintained for patients who do not 
qualify for enrollment, including the reason for the failure. 
7.4 
STUDY MONITORING 
Ironwood performs quality control and assurance checks on all of its clinical studies. Before any 
patients are enrolled in the study, a representative of Ironwood or its authorized designee will 
meet with the Investigator and his/her staff to review relevant and important study-related 
information including, but not limited to, the protocol, the Investigator’s Brochure, the eCRFs 
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and instructions for their completion using the EDC system, the procedure for obtaining 
informed consent, and the procedure for reporting AEs and SAEs. 
An Ironwood representative, the Clinical Site Monitor, will monitor the progress and conduct of 
the study by periodically conducting monitoring visits and by frequent communications 
(telephone, e-mail, letter, and fax) with the study sites. The site monitor will ensure that the study 
is conducted according to the protocol and regulatory requirements. During monitoring visits, the 
information recorded on the eCRFs will be verified against source documents. Upon request of 
the monitor, auditor, IRB, or regulatory authority, the Investigator should make all requested 
study-related records available for direct access. 
All aspects of the study will be carefully monitored by Ironwood or its designee for compliance 
with applicable government regulations with respect to GCP and current standard operating 
procedures. 
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8. 
STUDY SPONSORSHIP 
8.1 
INVESTIGATOR AND STUDY TERMINATION 
Ironwood may terminate Investigator participation at any institution for any reason. If 
participation is ended at the site by either Ironwood or the Investigator, the Investigator must: 
• Return all study medications and any study materials to Ironwood 
• In cases where the Investigator opts to self-terminate, provide a written statement describing 
why the study was terminated prematurely 
 
Ironwood may terminate the study in its entirety or at a specific center at any time for any 
reason, including but not limited to the following: 
• Failure to enroll patients 
• Protocol violations 
• Inaccurate or incomplete data 
• Unsafe or unethical practice 
• Questionable safety of the study medication 
• Suspected lack of efficacy of the study medication  
• Administrative decision 
 
8.2 
REPORTING AND PUBLICATION 
 All data generated in this study will be the property of Ironwood. An integrated clinical and 
statistical report will be prepared at the completion of the study. 
Publication of the results by the Investigator will be subject to agreement between the 
Investigator and Ironwood. 
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9. 
INVESTIGATOR OBLIGATIONS 
9.1 
DOCUMENTATION 
The Investigator must provide the Sponsor with the following documents BEFORE the 
enrollment of any subjects, in accordance with ICH E6 (Note: Ironwood must be notified if there 
are any changes to these documents): 
1. Completed and signed Form FDA 1572 (Statement of Investigator) including all sub-
investigators involved in the study 
2. Financial disclosure form(s) for the Investigator and all sub-investigators listed on Form 
FDA 1572 
3. Current, signed curricula vitae of the Investigator and all sub-investigators 
4. Copy of current medical license of the Investigator and all sub-investigators (as applicable) 
5. Copy of the IRB approval letter for the protocol and ICF 
6. Copy of the IRB-approved ICF to be used 
7. Copy of the IRB approval of recruitment advertising (if applicable) 
8. A list of IRB members and their qualifications, and a description of the committee’s working 
procedures 
9. Protocol Approval Page signed by the Investigator 
10. Fully executed Clinical Trial Agreement 
11. Written document containing the name, location, certification number, and date of 
certification of the local laboratory to be used for laboratory assays and those of other 
facilities conducting tests 
12. List of normal laboratory values and units of measurements for all laboratory tests required 
by the protocol. This list is required for each local laboratory to be used during the study. 
 
During the study, the Investigator must maintain the following essential/administrative 
documents related to the study: 
1. Copy of the signed Protocol Signature Page 
2. Copy of financial disclosure form(s) for the Investigator and all sub-investigators (as 
applicable) if updated 
3. Curricula vitae of any new Investigator(s) and/or sub-investigators involved in the study 
4. Copy of current medical license of the Investigator and all sub-investigators (as applicable) if 
updated 
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5. Copy of the signed Form FDA 1572 
6. IRB Approval Notification for the following: 
a. Protocol 
b. Informed consent document 
c. Recruitment advertising (if applicable) 
d. Amendment(s) (if applicable) 
e. Annual review of the protocol and the informed consent document 
f. SAEs 
g. Study closure 
7. SAE Reports 
8. Drug Inventory Forms (drug receipts, drug dispensing, and inventory forms) 
9. Name and address of local or central laboratory, list of normal laboratory values and units of 
measurement, as well as laboratory certification or hospital accreditation 
10. Updates of medical/laboratory/technical procedures/tests: 
a. Normal value(s)/ranges(s) 
b. Certification 
c. Accreditation 
d. Established quality control and/or external quality assessment 
e. Other validation (where required) 
11. Record of retained body fluids/tissue samples (if any) 
12. Correspondence with Sponsor 
13. Written assurance of continuing approval (at least annually) as well as a copy of the annual 
progress report submitted to the IRB must also be provided to the Sponsor. Any changes in 
this study or unanticipated problems involving risks to the patients must be reported 
promptly to the IRB. An Investigator must not make any changes in a study without IRB and 
Sponsor approval, except when necessary to eliminate apparent immediate hazards to the 
subjects. All protocol amendments must be submitted to the IRB and approved. 
14. Responsibility Log 
15. Other logs (eg, screening, enrollment) 
16. Signed ICFs 
17. Patient source documentation 
18. eCRFs 
19. Audit certificate(s), if applicable 
 
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9.2 
PERFORMANCE 
The Investigator must demonstrate reasonable efforts to obtain qualified patients for the study. 
The Sponsor may terminate the study with any Investigator for any reason, including, but not 
limited to, Investigator nonperformance or Investigator noncompliance. 
9.3 
USE OF INVESTIGATIONAL MATERIALS 
The Investigator will acknowledge that the drug supplies are investigational and as such must be 
used strictly in accordance with the protocol and only under the supervision of the Investigator or 
sub-investigators. Study medication must be stored in a safe and secure temperature-monitored 
location. The Investigator must maintain adequate records documenting the receipt and 
disposition of all study supplies. The study site must record the date the study medication was 
received and maintain a dispensing record in which to record each patient’s use. A complete 
reconciliation of study medication will be performed at the site close-out visit with a final 
accountability report provided to Ironwood as part of the site close-out report. Written 
instructions for return of all unused and reconciled study medication to an appropriate waste 
handler will be provided before the end of the study. No study medication may be destroyed by 
study site without prior written permission of Ironwood. 
9.4 
RETENTION AND REVIEW OF RECORDS 
Records and documents pertaining to the conduct of this study, including eCRFs, source 
documents, ICFs, laboratory test results, and medication inventory records, must be retained by 
the Investigator in accordance with locally applicable regulatory requirements; and, in any event, 
for a minimum period of 5 years.  
No study records shall be destroyed without notifying Sponsor and giving Sponsor the 
opportunity to take such study records or authorizing in writing the destruction of records after 
the required retention period. 
If the Investigator retires, relocates, or otherwise withdraws from the responsibility of keeping 
the study records, custody must be transferred to another person (Ironwood, IRB, or other 
Investigator) who will accept the responsibility. Ironwood must be notified of and agree to the 
change. 
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9.5 
PATIENT CONFIDENTIALITY 
All data collected in the context of this study will be stored and evaluated in such a way as to 
guarantee patient confidentiality in accordance with the legal stipulations applying to 
confidentiality of data. All patient records will be identified only by initials and patient 
identification (PID) number. Patient names are not to be transmitted to Ironwood or its 
authorized designee. The Investigator will keep a Master Patient List on which the PID number 
and the full name, address, and telephone number of each patient is listed. 
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10. 
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26. Ott IM, Alter ML, von WK, Kretschmer A, Tsuprykov O, Sharkovska Y, et al. Effects of 
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12. 
INVESTIGATOR’S SIGNATURE 
Study Title: 
A Randomized, Double-blind, Placebo-controlled, Phase 2 Study to 
Evaluate the Safety and Efficacy of IW-1973 in Patients with Type 2 
Diabetes with Albuminuria Treated with Renin-Angiotensin System 
Inhibitors 
Study Number: 
C1973-203 
Final Date: 
20 December 2017 
I have read the protocol described above. I agree to comply with all applicable regulations and to 
conduct the study as described in the protocol.  
 
 
Signed: 
 
 
Date:  
 
 
Print Name: 
 
 
 
 
 
 
 
 
 
 
 
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APPENDIX 1 
PROHIBITED MEDICINES AND SUPPLEMENTS  
 
Prohibited from 7 days before Randomization (Day 1) through the duration of the study 
• Specific inhibitors of PDE5, including sildenafil, tadalafil, vardenafil 
• All supplements for the treatment of erectile dysfunction 
• Nonspecific inhibitors of PDE5, including dipyridamole, theophylline 
• Other sGC stimulators, including riociguat 
• Nitrates including nitroglycerin, isosorbide mononitrate, isosorbide dinitrate, sodium 
nitroprusside, amyl nitrate  
• Other NO donors in any form, including beetroot 
Prohibited from 14 days before Randomization (Day 1) through the duration of the study
• Strong inhibitors of CYP3A, including azole antifungals (eg, itraconazole, posaconazole), 
conivaptan, diltiazem, idelalisib, macrolide antibiotics (eg, clarithromycin, telithromycin), 
nefazodone, protease inhibitors (eg, ritonavir, boceprivir), and excessive grapefruit intake 
or concentrated grapefruit supplements 
CYP=cytochrome P450; NO=nitric oxide; PDE=phosphodiesterase 
 
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20 December 2017 
 
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APPENDIX 2 
 
APPENDIX 2 
 
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APPENDIX 3 
 
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APPENDIX 4 
 
 
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