Clinical trial NCT02589847
Conditions: Clostridium Difficile Infection
Keywords: Clostridium difficile C diff CDI CDAD Fecal transplant Fecal Microbiota transplant diarrhea FMT microbiota restoration therapy microbiota suspension fecal bacteriotherapy C diff diarrhea
Sponsor: Rebiotix Inc.
Start date: 2015-10-01; Completion date: 2019-03-01
Enrollment: 272 participants; Allocation: NON_RANDOMIZED; Intervention model: PARALLEL

Brief summary:
This study will evaluate efficacy and safety information about RBX2660 for the treatment of recurrent Clostridium difficile infection (CDI), and will compare the efficacy of one treatment with RBX2660 versus antibiotic-treated historical controls. Enrolled subjects will receive one treatment consisting of two doses of RBX2660 (microbiota suspension).

Detailed description:
This is a prospective, multicenter, open-label study assessing the efficacy and safety of RBX2660 as an adjunct to antibiotics for the treatment of recurrent CDI. Efficacy of RBX2660, measured by the recurrence-free rate of CDI diarrhea without the need for retreatment with C. difficile anti-infective therapy or fecal transplant through 56 days after completion of study treatment with RBX2660, will be evaluated by comparing the recurrence-free rate observed in the study population to the recurrence-free rate identified from antibiotic-treated historical controls.

Patients who have had either a) at least two recurrences after a primary episode (i.e., at least three episodes) and have completed at least two rounds of standard-of-care oral antibiotics or b) have had at least two episodes of severe CDI resulting in hospitalization may be eligible to participate in the study. Study visits are 1- and 8-weeks after treatment with additional follow-up assessments at 3,6,12, and 24 months post treatment.

Arms: arm 1: RBX2660 (microbiota suspension) arm 2: Retrospective Historical Control with standard of care
Interventions: intervention 1: RBX2660 intervention 2: Standard of Care Antibiotics
Intervention descriptions: intervention 1: suspension of intestinal microbes intervention 2: Standard of Care Antibiotics

Protocol documents:
Prot_000.pdf: 
Rebiotix Inc. 
Protocol 2015-01 
 An Open-label Efficacy and Safety Assessment of Rebiotix 
RBX2660 (microbiota suspension) for the Treatment of 
Recurrent Clostridium difficile Infection  
NCT02589847 
Version 5.0, Date 20 Jan 2016 
 











































































































































SAP_001.pdf: 
Rebiotix Inc. 
Protocol 2015-01 
 
Statistical Analysis Plan  
NCT02589847 
Version 3.0, Date 01 Apr 2019 
 






Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
3 of 30 
Version 3.0 
CONFIDENTIAL 
 
 
Contents 
1 
LIST OF ABBREVIATIONS AND DEFINITIONS OF TERMS ................................................................... 5 
2 
INTRODUCTION ............................................................................................................................................... 6 
3 
STUDY OBJECTIVES AND ENDPOINTS ...................................................................................................... 6 
3.1 
PRIMARY OBJECTIVE ...................................................................................................................................... 6 
3.2 
SECONDARY OBJECTIVES ............................................................................................................................... 6 
3.3 
PRIMARY ENDPOINT ....................................................................................................................................... 6 
3.4 
SECONDARY ENDPOINTS ................................................................................................................................ 7 
4 
STUDY DESIGN ................................................................................................................................................. 8 
4.1 
GENERAL DESIGN ........................................................................................................................................... 8 
4.1.1 
Definition of Recurrent CDI for Study Entry ......................................................................................... 9 
4.1.2 
Definition of CDI Diarrhea ................................................................................................................... 9 
4.1.3 
Definition of Treatment Success ............................................................................................................ 9 
4.1.4 
Definition of Treatment Failure (CDI Recurrence) ............................................................................... 9 
4.1.5 
Management of Treatment Failures ..................................................................................................... 10 
4.1.6 
Determination of Treatment Success/Failure ...................................................................................... 10 
4.1.7 
Discontinuation before Determination of Treatment Outcome ............................................................ 10 
4.2 
DISCUSSION OF STUDY DESIGN .................................................................................................................... 10 
4.3 
BLINDING ..................................................................................................................................................... 11 
4.4 
METHOD OF ASSIGNMENT OF SUBJECTS TO TREATMENT ARMS ................................................................... 11 
4.5 
DETERMINATION OF SAMPLE SIZE ................................................................................................................ 11 
4.6 
INTERIM SAMPLE SIZE RE-ESTIMATION ........................................................................................................ 12 
4.7 
TREATMENT ARMS ....................................................................................................................................... 12 
5 
CHANGES IN THE CONDUCT OF THE STUDY OR PLANNED ANALYSES ...................................... 12 
5.1 
CHANGES IN THE CONDUCT OF THE STUDY .................................................................................................. 12 
6 
BASELINE, EFFICACY AND SAFETY EVALUATIONS .......................................................................... 13 
6.1 
SCHEDULE OF EVENTS .................................................................................................................................. 13 
6.2 
TIME POINT ALGORITHMS ............................................................................................................................ 14 
6.2.1 
Relative Day......................................................................................................................................... 14 
6.2.2 
Windows ............................................................................................................................................... 14 
6.3 
ANALYSIS POPULATIONS .............................................................................................................................. 15 
6.4 
SAFETY VARIABLES ..................................................................................................................................... 16 
6.4.1 
Extent of Exposure to Study Treatment ................................................................................................ 16 
6.4.2 
Adverse Events ..................................................................................................................................... 17 
6.4.3 
Other Observations Related to Safety .................................................................................................. 19 
6.5 
EFFICACY VARIABLES .................................................................................................................................. 20 
7 
STATISTICAL METHODS ............................................................................................................................. 20 
7.1 
GENERAL METHODOLOGY............................................................................................................................ 20 
7.2 
ADJUSTMENTS FOR COVARIATES.................................................................................................................. 21 
7.3 
HANDLING OF DROPOUTS OR MISSING DATA ............................................................................................... 21 


Rebiotix Inc 
Protocol 2015-01 
Statistical Analysis Plan 
01 Apr 2019 
  
4 of 30 
Version 3.0 
CONFIDENTIAL 
7.4 
MEDICAL MONITOR ADJUDICATION ............................................................................................................. 21 
7.5 
INTERIM ANALYSES ...................................................................................................................................... 22 
7.5.1 
Study Stopping Rules ........................................................................................................................... 22 
7.6 
MULTI-CENTER STUDIES AND POOLING OF CENTERS ................................................................................... 23 
7.7 
MULTIPLE COMPARISONS/MULTIPLICITY ..................................................................................................... 23 
7.8 
EXAMINATION OF SUBGROUPS ..................................................................................................................... 23 
8 
STATISTICAL ANALYSIS ............................................................................................................................. 23 
8.1 
DISPOSITION OF SUBJECTS ............................................................................................................................ 23 
8.2 
PROTOCOL DEVIATIONS ............................................................................................................................... 24 
8.3 
BASELINE ASSESSMENTS .............................................................................................................................. 24 
8.4 
DEMOGRAPHIC AND OTHER BASELINE CHARACTERISTICS ........................................................................... 24 
8.5 
PRIOR AND CONCOMITANT THERAPY ........................................................................................................... 25 
8.6 
ANALYSIS OF SAFETY ................................................................................................................................... 25 
8.6.1 
Adverse Events ..................................................................................................................................... 25 
8.6.2 
Other Analyses Related to Safety ......................................................................................................... 27 
8.7 
ANALYSIS OF EFFICACY ............................................................................................................................... 29 
8.7.1 
Treatment Success ............................................................................................................................... 29 
8.7.2 
Change from Baseline SF-36 scores at 8-week assessment visit ......................................................... 30 
8.7.3 
Subgroup Analysis ............................................................................................................................... 30 
9 
COMPUTER SOFTWARE .............................................................................................................................. 30 




Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
6 of 30 
Version 3.0 
CONFIDENTIAL 
2 
INTRODUCTION 
RBX2660 (microbiota suspension) is being studied for the treatment of adult subjects as an 
adjunct to antibiotics for the treatment of recurrent Clostridium difficile infection (CDI). The 
purpose of this study is to evaluate the efficacy and safety of RBX2660 for the treatment of 
recurrent CDI in subjects who have had either a) at least two recurrences after a primary episode 
(i.e., at least three episodes) and have completed at least two rounds of standard-of-care oral 
antibiotic therapy or b) have had at least two episodes of severe CDI resulting in hospitalization. 
 
3 
STUDY OBJECTIVES AND ENDPOINTS 
3.1 
Primary Objective 
The primary objective of this study is to compare the efficacy, defined as the absence of CDI 
diarrhea without the need for retreatment with C. difficile anti-infective therapy or fecal 
transplant (FT) through 56 days after treatment, of one treatment with RBX2660 (one treatment 
consists of two enemas of RBX2660 7 ± 2 days apart) versus antibiotic-treated historical 
controls. 
 
3.2 
Secondary Objectives 
The secondary objectives of this study are: 
1. To evaluate the safety of RBX2660. 
2. To evaluate the effect of RBX2660 on pre-existing conditions other than recurrent CDI. 
3. To evaluate quality of life as measured by the SF-36 Health Survey. 
4. To evaluate the efficacy of C. difficile anti-infection therapies administered to confirmed 
treatment failures. 
 
3.3 
Primary Endpoint 
Efficacy, measured by the recurrence-free rate of CDI diarrhea without the need for retreatment 
with C. difficile anti-infective therapy or fecal transplant through 56 days after completion of 


Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
7 of 30 
Version 3.0 
CONFIDENTIAL 
study treatment with RBX2660, will be evaluated by comparing the recurrence-free rate 
observed in the study population to the recurrence-free rate identified from antibiotic-treated 
historical controls. 
 
3.4 
Secondary Endpoints 
The secondary endpoints for this study are: 
1. The frequencies and severity grades of solicited AEs from the first day of assigned study 
treatment through seven days following the last enema of assigned study treatment will 
be collected. 
2. Adverse events, including serious adverse events and the onset of new chronic diseases, 
will be collected at in-office visits at 1, 4, and 8 weeks and at 3-, 6-, and 12-month calls; 
they will be categorized by frequency, severity, seriousness, and causality. 
3. Serious adverse events and new onset of chronic diseases will be collected at a telephone 
call at 24 months and will be categorized by frequency, severity, seriousness, and 
causality. 
4. Frequencies of major complications of CDI including death, septic shock, toxic 
megacolon, colonic perforation, emergency colectomy, or ICU admission will be 
collected through the 24-month telephone assessment. 
5. The effect of RBX2660 on pre-existing conditions other than recurrent CDI will be 
assessed by comparing the change in the condition throughout the course of the study. 
6. SF-36 scores recorded at the Week 8 visit will be compared to scores recorded at the 
screening visit. 
7. Efficacy of C. difficile anti-infection therapies administered to confirmed treatment 
failures will be compared to each other for the rates of success at resolving CDI diarrhea 
for at least 56 days after completion of the anti-infection therapy. 
 


Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
8 of 30 
Version 3.0 
CONFIDENTIAL 
4 
STUDY DESIGN 
4.1 
General Design 
This is a prospective, multicenter, open-label study assessing the efficacy and safety of 
RBX2660 as an adjunct to antibiotics for the treatment of recurrent CDI.  Up to approximately 
150 subjects will be enrolled in this study and receive RBX2260.  Approximately 100 historical 
controls will be chosen from a retrospective chart review of patients treated with antibiotics for 
recurrent CDI who match key inclusion/exclusion criteria from the study. 
 
Subjects who meet all inclusion and exclusion criteria, including having a positive C. difficile 
test within 60 days prior to enrollment and experiencing either a) at least two recurrences after a 
primary episode (diagnosis must include at least one positive C. difficile test on record within 60 
days prior to enrollment) and have completed at least two rounds of standard-of-care oral 
antibiotic therapy or b) have had at least two episodes of severe CDI resulting in hospitalization 
prior to enrollment, will receive open-label treatment with RBX2660.  One study treatment 
consists of two RBX2660 enemas administered 7 ± 2 days apart; the second enema may be 
administered sooner if CDI diarrhea reoccurs in less than 7 days.  Subjects will already be taking 
or will start a course of antibiotics to control recurrent CDI diarrhea at the time of enrollment,  
 
 
 
  An in-office follow-up visit will occur at 8 weeks after completing 
study treatment for the assessment of AEs, efficacy, collection of the Subject Diary, and blood 
tests.  Telephone assessments for AEs including serious adverse events (SAEs) and the new 
onset of chronic diseases and CDI symptoms will occur at weeks 1, 2, 3, and 4 and at 3, 6, and 
12 months after completing study treatment.  Assessment of serious adverse events and the new 
onset of chronic diseases will occur via phone call at 24 months after completing study 
treatment.  Subjects will keep a detailed Subject Diary to assess for solicited adverse events from 
the date of enrollment to one week after completing study treatment (second enema). Treatment 


Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
9 of 30 
Version 3.0 
CONFIDENTIAL 
failures (as determined by the site investigator at the time of CDI recurrence) are eligible to 
receive another therapy deemed most appropriate by their study investigator. 
 
 
 
 
 
 
 
 
4.1.2 
Definition of CDI Diarrhea 
Clostridium difficile diarrhea is defined as the passage of ≥ 3 watery stools in 24 or fewer 
consecutive hours for at least two consecutive days. 
 
4.1.3 
Definition of Treatment Success 
Treatment success is defined as the absence of CDI diarrhea without the need for retreatment 
with C. difficile anti-infective therapy or FT through 56 days after completion of study treatment.   
 
4.1.4 
Definition of Treatment Failure (CDI Recurrence) 
Treatment failure (CDI recurrence) is defined as: 1) the presence of CDI diarrhea (see Section 
4.1.2), with or without other CDI symptoms, < 56 days after administration of the last assigned 
study enema; 2) a positive stool test for C. difficile; 3) need for retreatment for C. difficile 
infection; and 4) no other cause for CDI symptoms has been determined.  
 
 
 
 
 


Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
10 of 30 
Version 3.0 
CONFIDENTIAL 
 
   
 
4.1.5 
Management of Treatment Failures 
Treatment failures (as determined by the site investigator at the time of CDI recurrence) are to be 
treated with another therapy(ies) deemed most appropriate by their study investigator.   
 
4.1.6 
Determination of Treatment Success/Failure 
The site investigator makes the determination of success based on the absence of CDI diarrhea 
without the need for retreatment with C. difficile anti-infective therapy or FT at less than 56 days 
after administration of the last assigned study enema;
 
 
 
 
   
 
4.2 
Discussion of Study Design 
Screening will be performed before treatment and will include demographics, a complete 
medical history, a review of inclusion/exclusion criteria, stool and blood testing, a modified 
physical exam, Form SF-36 completion, vital signs, Subject Diary recording, and urine 
pregnancy test for all females of childbearing potential.  
 
The target population is adults (≥ 18 years old) with recurrent CDI who have had either a) at 
least two recurrences after a primary episode 
 
 and have completed at least two rounds of standard-of-care oral antibiotic 
therapy or b) have had at least two episodes of severe CDI resulting in hospitalization. 
 


Rebiotix Inc 
Protocol 2015-01 
Statistical Analysis Plan 
01 Apr 2019 
  
11 of 30 
Version 3.0 
CONFIDENTIAL 
For study entry, recurrent CDI is defined as a documented diagnosis of recurrent CDI 
(recurrence of CDI symptoms for at least two consecutive days that begins less than 8 weeks 
after completion of CDI treatment) and at least one positive stool test for the presence of C. 
difficile on record within 60 days prior to enrollment.  
4.3 
Blinding 
This is an open-label study; no blinding will be employed. 
4.4 
Method of Assignment of Subjects to Treatment Arms 
This study consists of a single prospective treatment arm, to which all eligible subjects are 
assigned.  A historical control arm, consisting of patients treated with antibiotics for recurrent 
CDI, will also be used for efficacy analysis. 
 
  No randomization is 
employed in this study. 
4.5 
Determination of Sample Size 
Approximately up to 150 subjects will be enrolled in this study and receive RBX2660; and 
another 100 historical controls with recurrent CDI diarrhea will also be included in the study 
based on a retrospective chart review. 
The primary analysis will compare the proportion of subjects in the treatment arm who are 
recurrence-free to the proportion of historical controls who are recurrence-free. 
 
 
 
 
 


Rebiotix Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
12 of 30 
Version 3.0 
CONFIDENTIAL 
 
 
 
 
 
 
 
  
 
 
 
 
4.7 
Treatment Arms 
The open-label study consists of a single prospective treatment arm and historical control group, 
as described below. 
• One treatment with RBX2660:  one treatment consists of two enemas of RBX2660 
administered 7 ± 2 days apart (the second enema may be administered sooner if CDI 
diarrhea reoccurs in less than 7 days). 
 
 
• Historical control group chosen from a retrospective chart review. 
 
5 
CHANGES IN THE CONDUCT OF THE STUDY OR PLANNED ANALYSES 
5.1 
Changes in the Conduct of the Study 
The SAP was previously updated to allow an historical control arm of approximately 100 
subjects to be included in the study. These subjects were chosen from retrospective chart reviews 
to obtain a closely matched data set of the standard of care antibiotic treatment for recurrent CDI 
to the RBX2660 treated subjects based on a number of baseline factors. The historical control 
arm allows for efficacy comparisons to be performed. 








Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
16 of 30 
Version 3.0 
CONFIDENTIAL 
• Subjects that received fecal microbiota transplant before the 8-week follow-up and lacked 
a documented recurrence of CDI (Treatment Failure eCRF) 
• Violations to the inclusion or exclusion criteria, including protocol definition of recurrent 
CDI two hospitalizations for CDI or 3 recurrent CDI events 
• Received prohibited medication during the 8-week follow-up period 
 
 
6.4 
Safety Variables 
Safety variables to be evaluated in the study include: 
• Adverse events (AEs) 
• Serious adverse events (SAEs) 
• Solicited AEs 
• Frequency of major complications of recurrent CDI including death, septic shock, toxic 
megacolon, colonic perforation, emergency colectomy, or ICU admission. 
 
 
 
 
 
 
 
 
 
 
 
 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
17 of 30 
Version 3.0 
CONFIDENTIAL 
 
6.4.2 Adverse Events 
An adverse event (AE) is any untoward medical occurrence associated with the use of RBX2660, 
whether or not the event is considered product-related. Pre-existing conditions that worsen in 
frequency, intensity or character of the condition during study participation will be recorded as 
an AE. Adverse events will be recorded for each subject from the day of enrollment through the 
12-month phone call. Serious adverse events (SAEs) and the new onset of chronic diseases will 
be recorded for each subject from the day of enrollment through the duration of the study. 
 
6.4.2.1 Adverse Event Dictionary 
Adverse events and SAEs will be classified by the Medical Dictionary for Regulatory Activities 
(MedDRA) 
 
 
 
 
 
6.4.2.2 Adverse Event Severity 
The severity of AEs will be graded as mild, moderate, severe, or potentially life-threatening. The 
severity grade of events for which the investigator does not record severity will be categorized as 
“Unknown” for tabular summaries and data listings, and will be considered the least severe for the 
purposes of sorting for data presentation. For summaries by severity grade, if a subject has multiple 
events occurring in the same SOC or PT, then the most severe event will be selected. 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
18 of 30 
Version 3.0 
CONFIDENTIAL 
6.4.2.3 Relationship of Adverse Events to Study Treatment 
Causal relationship of an AE to RBX2660, the enema procedure, C. difficile disease, and/or a 
pre-existing condition will be classified by the investigator as definite, probable, possible, or 
unrelated. Related events will include AEs that are classified as definitely, probably or possibly 
related. Events for which the investigator does not record causal relationship will be considered 
"Related" for tabular summaries and data listings. 
 
6.4.2.4 Treatment-Emergent Adverse Events 
Adverse events will be considered treatment-emergent adverse events (TEAE) according to the 
following algorithm, and will be applied to the Full Analysis Set population: 
• If the complete onset date of an AE is known, then: 
o If the AE onset date is prior to initial treatment date, then the AE will not be considered 
treatment-emergent. 
o If the AE onset date occurs on or after initial treatment date, then the AE will be 
considered treatment-emergent. 
• If the AE onset date is partially known, then: 
o If day is unknown, and month/year occur on or after the first enema month/year, then the 
AE will be considered treatment-emergent. Otherwise, the AE will not be considered 
treatment-emergent. 
o If month/day is unknown, and year occurs on or after first enema year, then the AE will 
be considered treatment-emergent. Otherwise, the AE will not be considered treatment-
emergent. 
• If the onset date of an AE is unknown, then the following rules will apply: 
o If the AE resolution date is after the initial treatment date or ongoing, then the AE will be 
considered treatment-emergent. 
o If the AE resolution date is before the initial treatment date, then the AE will not be 
considered treatment-emergent. 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
19 of 30 
Version 3.0 
CONFIDENTIAL 
o If both the onset and resolution dates are unknown, then the AE will be considered 
treatment-emergent. 
 
6.4.3 
Other Observations Related to Safety 
6.4.3.1 Solicited Adverse Events 
The following list of anticipated adverse events is solicited from subjects via the Subject Diary 
from the date of enrollment through the 7th day after receiving the last study treatment.  
• gas (flatulence) 
• abdominal distension or bloating 
• rectal irritation or pain 
• chills/severe shivering 
• abdominal pain or cramping 
• increased diarrhea 
• constipation 
• rectal bleeding 
• nausea 
• vomiting 
• fever ≥ 38.0° C (100.4°F) 
 
Frequency and severity of the solicited AEs will be recorded in the Subject Diary. 
6.4.3.2 Major Complications of Recurrent CDI 
The frequencies of major complications of recurrent CDI including death, septic shock, toxic 
megacolon, colonic perforation, emergency colectomy, or ICU admission will be collected 
through the 24-month telephone assessment. 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
20 of 30 
Version 3.0 
CONFIDENTIAL 
6.4.3.3 Pre-existing Conditions 
A pre-existing condition is one that is present at the start of the study and is to be recorded at the 
time of the screening or baseline visits.  Pre-existing conditions are assessed at the 3-, 6-, 12-, 
and 24-month telephone assessments. The assessment of pre-existing conditions includes 
discussion with the subject to determine if the condition improved, unchanged, worsened or 
resolved since completion of study treatment.   
 
6.5 
Efficacy Variables 
The efficacy variables include the following:  
• Treatment success, defined as the absence of CDI diarrhea without the need for 
retreatment with C. difficile anti-infective therapy or fecal transplant (FT) through 56 
days after administration of the last study enema. 
• SF-36 scores obtained at the 8-week assessments visits as compared to those obtained at 
the Screening visit. 
 
7 
STATISTICAL METHODS 
7.1 
General Methodology 
All statistical tests will be performed using SAS 
. For continuous 
variables, descriptive statistics (number of subjects [N], mean, standard deviation [SD], median, 
inter-quartile range [IQR], minimum, and maximum) will be generated. For discrete/categorical 
variables, the number and percentage of non-missing subjects will be generated. Descriptive 
statistics will be provided for all subjects. 
 
  Subject 
listings of all data from the eCRFs as well as any derived variables will be presented. 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
01 Apr 2019 
  
21 of 30 
Version 3.0 
CONFIDENTIAL 
 
 
 
 
 
7.3 
Handling of Dropouts or Missing Data 
The safety assessment will be analyzed using all available data only. No imputation of missing 
data is planned for the safety assessment.   
 
Efficacy assessments will also be analyzed using all available data. If there are treated subjects 
with missing efficacy data by 56 days 
 after completion of study treatment (e.g., 
subject discontinues study prior to evaluation of treatment outcome), the subject’s treatment 
outcome will be listed as “missing”, and for the primary analysis purpose will be handled as a 
treatment failure.  
 
 
 
7.4 
Medical Monitor Adjudication 
An independent Medical Monitor reviews all serious adverse events and adverse events of 
interest to provide an objective, qualified judgment of the events.  The Medical Monitor is a 
physician not participating as an investigator in this study. The Medical Monitor has the 
responsibility to review and evaluate the information relevant to product safety throughout the 
development and implementation of the protocol.  The Medical Monitor performs the following 
functions: 
• Reviews and adjudicates SAEs and AEs of interest; 
• Reviews the study protocol and Investigator’s Brochure for adequacy of safety oversight; 
• Confers with site investigators and the Rebiotix Clinical Department regarding potential 
safety concerns as needed; 
• Provides medical surveillance and provides appropriate recommendations for the conduct 
of the study as needed. 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
22 of 30 
Version 3.0 
CONFIDENTIAL 
 
7.5 
Interim Analyses 
Efficacy and safety analyses will be conducted when approximately 100 enrolled subjects 
complete their 8-week assessment.   The study will not be stopped based on the efficacy results. 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
01 Apr 2019 
  
23 of 30 
Version 3.0 
CONFIDENTIAL 
 
 
 
 
  
 
 
 
 
 
7.8 
Examination of Subgroups 
Subgroup analysis of age (< 65 years, ≥ 65 years), sex (Female, Male), ethnicity (Hispanic or 
Latino, or Not Hispanic or Latino), race group (American Indian or Alaskan Native, Asian, 
Black or African American, Native Hawaiian or other Pacific Islander, White, and Other, as well 
as White and Non-white), and number of previous episodes of CDI recurrence at baseline will be 
conducted on the efficacy and safety analysis.  
 
8 
STATISTICAL ANALYSIS 
8.1 
Disposition of Subjects 
A summary table will present subject disposition for all subjects. The table will show the number 
of RBX2660 treated subjects enrolled and the number of enrolled subjects not treated followed 
by the number of subjects in the study population as well as the number of historical controls 
included in the study. 
 
 
 
 
Discontinuation will be categorized by reason as a percentage of the number of all subjects in 
study population.  
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
01 Apr 2019 
  
24 of 30 
Version 3.0 
CONFIDENTIAL 
 
 
 
 
 
8.3 
Baseline Assessments 
Baseline assessments are collected within 30 days before study treatment administration. 
Summaries for age (years), sex, ethnicity, and race will be provided for the Full Analysis Set. 
Baseline BMI and employment status will also be summarized. C. difficile infection history will 
be summarized by total number of episodes and by each episode. The following will be 
summarized for each episode of CDI: duration (days), treatment administered, hospitalization 
with duration (if applicable) and available C. difficile test results. 
 
For Form SF-36, the results obtained at the Screening visit will be used for the baseline 
assessment. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8.4 
Demographic and Other Baseline Characteristics 
All baseline summaries will be based on the Full Analysis Set and the Enrolled populations. 
Descriptive statistics (number of subjects [N], mean, standard deviation [SD], median, 
interquartile range [IQR], minimum, and maximum for continuous variables and number of 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
25 of 30 
Version 3.0 
CONFIDENTIAL 
subjects [N] and the percentage for categorical variables) will be provided for all baseline 
measures. 
  
8.5 
Prior and Concomitant Therapy  
The World Health Organization (WHO) Drug Dictionary 
 will be used 
to classify medications by preferred term and WHO Anatomical Therapeutic Chemical (ATC) 
level-4 classification of ingredients. Listings of all concomitant medications will be made by 
WHO ATC classification of ingredients and by preferred term. 
 
8.6 
Analysis of Safety 
The Full Analysis Set will be used to summarize all adverse event data, unless otherwise 
specified. The method of analyzing adverse event is described 
.  Adverse events 
from the historical control subjects will be summarized and will be included in listings. 
 
8.6.1 Adverse Events 
A summary of adverse events, TEAEs, non-serious TEAEs, and serious TEAEs will be 
summarized using counts of the number of events and frequencies (counts and percentages) of 
the number of subjects in the Full Analysis Set. The frequency of each preferred term (PT) 
within the primary system organ class (SOC) as well as overall primary SOC frequency will be 
presented. A subject with multiple events coded to the same PT within a primary SOC will be 
counted only once for the PT within the primary SOC. Likewise, a subject with multiple events 
coded to the same SOC will be counted only once within the SOC. Adverse events and serious 
adverse events will also be summarized by onset timepoint by system organ class (SOC) and 
preferred term (PT): 
 
 
 
Adverse events will be counted in the interval in 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
26 of 30 
Version 3.0 
CONFIDENTIAL 
which the start date of the event occurs. For subjects with multiple instances of the same event, 
the events will be counted once within each interval that the event starts.  
 
An overall summary of AEs will present the frequency of all TEAEs, serious TEAEs, and 
TEAEs leading to death for the Full Analysis Set, as well as the frequency of the following for 
the RBX2660 treatment group:   
• TEAEs related to RBX2660 
• TEAEs related to enema procedure 
• TEAEs related to C. difficile disease 
• TEAEs related to a pre-existing condition 
• Serious TEAEs related to RBX2660 
• Serious TEAEs related to the enema procedure 
• Serious TEAEs related to C. difficile disease 
• Serious TEAEs related to a pre-existing condition. 
 
Frequency of occurrence and number and percentage of subjects experiencing an event will be 
presented by SOC and PT using the Safety Population for the following: 
• TEAEs by maximum severity 
• TEAEs by relatedness to RBX2660 
• TEAEs by relatedness to C. difficile disease 
• TEAEs by relatedness to enema procedure 
• TEAEs by relatedness to pre-existing condition 
• Serious TEAEs 
• Serious TEAEs by maximum severity 
• Serious TEAEs by relatedness to RBX2660 
• Serious TEAEs by relatedness to C. difficile disease 
• Serious TEAEs by relatedness to enema procedure 
• Serious TEAEs by relatedness to pre-existing condition 


Rebiotix, Inc 
Protocol 2015-01 
Statistical Analysis Plan 
01 Apr 2019 
  
27 of 30 
Version 3.0 
CONFIDENTIAL 
For the summary of AEs by maximum severity, if a subject has multiple events occurring in the 
same SOC or same PT, then the event with the highest severity will be counted. For AEs 
reported by causality, if a subject has multiple events occurring in the same SOC or same PT, the 
event with the highest association will be summarized. 
A summary of TEAE and serious TEAE characteristics (severity, relatedness to RBX2660, 
relatedness to C. difficile disease, relatedness to enema procedure, and relatedness to pre-existing 
condition by outcome) will be presented for the Safety Population. 
A summary of TEAE and serious TEAE characteristics (severity, relatedness to RBX2660, 
relatedness to C. difficile disease, relatedness to enema procedure, and relatedness to pre-existing 
condition by outcome) by SOC will also be presented for the Safety Population. 
For data presentation, SOC will be ordered alphabetically, with PT sorted by decreasing total 
frequency. No inferential statistics will be provided for the AE data. 
Subject listings will be presented for all AEs and for SAEs. 
8.6.2 
Other Analyses Related to Safety 
8.6.2.1 Subject Diary including Solicited Adverse Events and Compliance 
All solicited adverse events recorded in the Subject Diary will be summarized utilizing 
frequencies, proportions and 95% CIs for categorical variables and using the descriptive statistics 
as listed in Section 7.1 for continuous variables.  
For each solicited event, severity scores will be summarized as both categorical and continuous 
values.  For continuous summaries, severity scores will be identified as either pre-treatment or 
post-treatment, and the average for each period will be calculated across individual subjects. 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
28 of 30 
Version 3.0 
CONFIDENTIAL 
Baseline for continuous summaries will be considered the average during the pre-treatment 
period. For categorical summaries, if a subject reports more than one severity score on the same 
date, the maximum severity will be used. Baseline for categorical summaries will be considered 
the last non-missing assessment prior to the first enema. 
 
For each categorical summary of event frequency, a two-sided 95% CI will be calculated using 
the normal approximation of the binomial. 
 
The following summaries will be produced relative to both the first and second enema: 
• Frequency of severity scores on day of enema administration 
• Frequency of severity scores on day 1 through day 7 post-treatment 
• Frequency of maximum post-treatment severity score 
 
The following summaries will be produced: 
• Summary of average severity score and change from baseline 
• Shift from baseline to 7-day post-treatment severity score 
• Shift from baseline to maximum post-treatment severity score  
 
Compliance in returning the Subject Diary will be calculated by dividing the number of diaries 
turned in, whether complete or not, by the number of diaries expected to be turned in. 
Furthermore, compliance will be summarized by calculating the proportion of subjects who 
turned in “complete” diaries, where complete is defined as answering all 14 daily questions for at 
least 80% of the expected number of diaries.  
 
8.6.2.2 Major Complications of Recurrent CDI  
Major complications of recurrent CDI include death, septic shock, toxic megacolon, colonic 
perforation, emergency colectomy, or ICU admission collected through the 24-month telephone 
assessment. Incidence of major complications of recurrent CDI will be summarized in a table. 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
29 of 30 
Version 3.0 
CONFIDENTIAL 
 
A listing of all major complications recurrent CDI throughout the study will be generated. 
 
 
 
 
 
 
 
 
 
8.7 
Analysis of Efficacy 
8.7.1 Treatment Success 
Treatment success is the primary efficacy endpoint and the analyses will be performed on the 
Evaluable Population. The primary endpoint will be summarized by frequencies and percentages 
 
The analysis of efficacy will be 
repeated using the Full Analysis Set and Per Protocol populations. Sensitivity analyses will also 
be conducted using the Full Analysis Set where missing responses are imputed using a best-case 
scenario where missing responses are treated as successes. 
 
 
 
 
 
 
 


Rebiotix, Inc 
Protocol 2015-01 
 
Statistical Analysis Plan 
 
01 Apr 2019 
  
30 of 30 
Version 3.0 
CONFIDENTIAL 
8.7.2 Change from Baseline SF-36 scores at 8-week assessment visit 
Eight subscales of the SF-36 (PF: Physical Functioning, RP: Role Physical, BP: Bodily Pain, 
GH: General Health, VT: Vitality, SF: Social Functioning, RE: Role Emotional, MH: Mental 
Health) and two summary component measures (PCS: Physical Component Summary, MCS: 
Mental Component Summary), and their changes from the baseline values collected at the 
Screening visit will be summarized using descriptive statistics for the Safety Population. Change 
from baseline of SF-36 scores will summarized at the scheduled 8-week visit using the Safety 
Population.  
 
 
 
 
 
 
 
 
 
 
9 
COMPUTER SOFTWARE 
All analyses will be performed 
 
All 
summary tables and data listings will be prepared utilizing SAS software.