Smith-Lemli-Opitz Syndrome: A Pilot Study of Cholic Acid Supplementation
Phase: PHASE1
Conditions: Smith-Lemli-Opitz Syndrome
Sponsor: University of Nebraska

RDCRN Protocol STAIR 7012        Cholic acid Therapy in SLOS         Version date 21Sept2020 
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Rare Diseases Clinical Research Network 
(RDCRN) 
 
Smith-Lemli-Opitz Syndrome: A Pilot Study of 
Cholic Acid Supplementation 
 
Sterol and Isoprenoid Research Consortium (STAIR) 
 
 
 
Ellen Roy Elias, M.D. 
Children’s Hospital Colorado 
13123 E 16th Ave, #B032 
Aurora, CO 80045 
Tel 720 777-5401 
Email: Ellen.Elias@childrenscolorado.org 
 
This protocol is for research purposes only, and should not be copied, 
redistributed or used for any other purpose.  The procedures in this 
protocol are intended only for use by Consortium investigators in carefully 
controlled settings.  The Chair of this study should be consulted before 
using or attempting any procedure in this protocol. 

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Participating Institutions/Investigators Table (contact information) 
 
Principal Investigator: Ellen Roy Elias, M.D. 
Contact:  Ellen R. Elias, MD 
Institution: Colorado Children’s Hospital 
Address: 13123 E. 16th Ave, #B032 
Aurora, CA 80045 
Phone: 720 777-5401 
Fax: 720 777-7347 
Email: Ellen.Elias@childrenscolorado.org  
Sub-Investigators: None 
  
 
Principal Investigator: William B. Rizzo, M.D. 
Contact:  Sara Jones, R.D., L.M.N.T 
Institution: University of Nebraska Medical Center 
Address: 985940 Nebraska Medical Center 
Omaha, NE 68198-5940 
Phone: 402-559-2560, 402-559-1747 
Fax: 402-559-2540 
Email: WRizzo@unmc.edu; SaraM.Jones@unmc.edu  
Sub-Investigators: None 
 
 
Data Management and Coordinating Center Principal Investigator: Eileen King, Ph.D. 
Contact:  Emily Oehler 
              Institution:  Cincinnati Children’s Hospital Medical Center 
Address: 3333 Burnet Avenue, Cincinnati, OH 45229 
Phone: 513- 803-8002 
Fax: 513-636-7509 
Email: Emily.Oehler@cchmc.org 
  
 
 
 

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Table of Contents 
 
 
Smith-Lemli-Opitz Syndrome: A Pilot Study of Cholic Acid Supplementation ............................ 1 
Participating Institutions/Investigators Table (contact information) .............................................. 2 
Table of Contents ............................................................................................................................ 3 
1. Protocol Synopsis ....................................................................................................................... 6 
1.1 Overview ............................................................................................................................... 8 
2. Specific Aims (Hypothesis and Objectives) ............................................................................... 9 
3. Background ................................................................................................................................. 9 
4. Study Design and Methods ....................................................................................................... 12 
4.1 Inclusion Criteria ................................................................................................................ 17 
4.2 Exclusion Criteria ............................................................................................................... 18 
4.3 Recruitment of Participants ................................................................................................. 18 
4.4 Retention Strategies ............................................................................................................ 18 
4.5 Data Elements ..................................................................................................................... 18 
4.6 Schedule of Events .............................................................................................................. 19 
5.0 Data and Safety Monitoring Plan ............................................................................................ 19 
5.1 Study Oversight .................................................................................................................. 20 
5.2 Definitions and Standards ................................................................................................... 20 
5.3 Expected/Known Risks/Discomforts/Adverse Events Associated with Study Intervention 
and Procedures: Definition of Expected Adverse Events ......................................................... 21 
5.4 Reporting Timeline ............................................................................................................. 21 
5.5 RDCRN Adverse Event Data Management System ........................................................... 22 
5.6 Study Discontinuation ......................................................................................................... 22 
5.7 Subject Withdrawal and/or Cholic Acid Dose Interuption/Reduction ............................... 23 
5.8 Data Quality and Monitoring Measures .............................................................................. 24 
5.9 Quality Control: Study Related Procedures ........................................................................ 24 
6. Statistical Considerations .......................................................................................................... 24 
7. Data Management ..................................................................................................................... 25 
7.1 Registration ......................................................................................................................... 25 
7.2 Data Entry ........................................................................................................................... 25 
7.3 Laboratory Data Flow ......................................................................................................... 25 
7.4 Study Records Retention ..................................................................................................... 26 

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7.5 Protocol Deviations ............................................................................................................. 26 
8. Human Subjects ........................................................................................................................ 26 
8.1 Good Clinical Practice Statement ....................................................................................... 26 
8.2 Benefits ............................................................................................................................... 26 
8.3 Risks .................................................................................................................................... 26 
8.4 Inclusion of Subjects  .......................................................................................................... 26 
8.5 Written Informed Consent .................................................................................................. 27 
8.6 Process of Consent .............................................................................................................. 27 
8.7 Certificate of Confidentiality .............................................................................................. 28 
9. References ................................................................................................................................. 28 
10. Appendices .............................................................................................................................. 29 
 
 
 
 

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List of Abbreviations 
AE, adverse event 
ALT, alanine aminotransferase  
AST, aspartate aminotransferase 
BID, twice daily 
BUN, blood urea nitrogen 
CBC, complete blood count 
CMP, comprehensive metabolic panel 
DHCR7, 7-dehydrocholesterol reductase 
7-DHC, 7-dehydrocholesterol 
8-DHC, 8-dehydrocholesterol 
DMCC, Data Management Coordinating Center 
DSMP, Data Safety Monitoring Plan 
FDA, Federal Drug Enforcement Agency 
GGT, gamma-glutamyltransferase 
G-tube, gastrostomy tube 
HMG-CoA, hydroxymethylglutaryl-Coenzyme A  
J-tube, jejunostomy tube 
MOO, Manual of Operations 
MRO, Medical Review Officer 
NIH, National Institutes of Health 
RDCRN, Rare Diseases Clinical Research Network 
SAE, serious adverse event 
SED, single enzyme defect 
SLOS, Smith-Lemli-Opitz syndrome 
STAIR, Sterol and Isoprenoid Research Consortium 
ZSD, Zellweger spectrum disorder 
 
 

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1. Protocol Synopsis 
Interventional Synopsis 
 
Protocol Number: STAIR 7012 
Protocol Title: Smith-Lemli-Opitz Syndrome: A Pilot Study of Cholic Acid 
Supplementation 
Study Chair: Ellen Roy Elias, M.D. 
Statistician: University of Nebraska Medical Center, TBD  
Consortium: Sterol and Isoprenoid Research Consortium (STAIR) 
Participating Sites: Children’s Hospital Colorado 
University of Nebraska Medical Center 
Activation Date: TBD 
Current Status: NIH and DSMB Approved 
Sample Size: Up to 15 enrollees with expectation to have 12 evaluable 
subjects 
Target Enrollment 
Period: 
September 2020- May 2021 
Study Design: Open-label, multi-center, pilot study 
Primary 
Objectives: 
1. Determine the effect of cholic acid supplementation on 
serum cholesterol and related sterol biomarkers (7- and 8-
dehydrocholesterol) in subjects with Smith-Lemli-Opitz 
syndrome (SLOS).  
2. Examine the safety of cholic acid administration to 
subjects with SLOS by measuring adverse events. 
Secondary 
Objectives: 
1. Determine the effect of cholic acid supplementation on 
serum oxysterol levels, serum bile acids, and vitamin D in 
subjects with SLOS.  
Exploratory 
Outcome 
Measures: 
1. Serum bile acid levels. 
2. Changes in safety monitoring tests including liver 
function as determined by serum transaminases, bilirubin, 
albumin, alkaline phosphatase, GGT and CBC. 
Study Population 
and Main 
Eligibility/ 
Exclusion Criteria: 
Subjects will be recruited through referrals from 
physicians at participating STAIR sites and subject 
referrals from the SLOS/RSH Foundation.  
 
Main Eligibility Criteria include: 
1. Parent/Guardian provide written consent. 
2. Subject has biochemically and genetically 
confirmed diagnosis of SLOS. 
3. Subject is ages 2-28 years at enrollment.  
4. Subject’s serum cholesterol ≤125 mg/dL prior to 
enrollment.  
5. Subject is currently on stable oral cholesterol 
supplementation. 

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6. Subject is able to travel to one of the STAIR sites. 
Main Exclusion Criteria include:  
1. Subject is clinically unstable.  
2. Subject is unlikely to complete the study, in the 
opinion of the investigator.  
3. Subject is taking drugs, nutraceutical, probiotics or 
other compounds that are known or suspected to 
lower serum cholesterol.  
4. Subject has transaminase elevations > 3-fold 
above the reference range at enrollment. 
5. Subject is pregnant or likely to become pregnant.  
Treatment (if applicable) 
Agent: Cholic acid (trade name Cholbam®; Retrophin, Inc.) 
Dosage, Schedule, 
Route of 
Administration: 
10 mg/kg/day, divided BID, administered either orally or 
via J- or G-Tube with a treatment duration of 2 months 
Safety Issues: Although previously administered to SLOS subjects, cholic 
acid has an undefined safety profile in SLOS subjects. In 
subjects with other disorders of cholesterol metabolism 
(Zellweger spectrum disorder and inherited single enzyme 
diseases of bile acid synthesis), worsening liver 
transaminases have been documented in a minority of 
treated subjects. These diseases are marked by inherent 
liver abnormalities prior to treatment. Due to the potential 
for worsening liver toxicity while on treatment with cholic 
acid, participants will be closely monitored for 
hepatotoxicity while on cholic acid and for one month 
following completion of the treatment trial. 
Primary Outcome 
Measures: 
Serum cholesterol, serum 7- and 8-dehydrocholesterol, 
sterol ratio, and incidence of adverse events. 
Secondary 
Outcome 
Measures: 
Serum oxysterol levels.  
Exploratory 
Outcome 
Measures: 
Serum vitamin D, serum bile acids, chemistries (AST, 
ALT, bilirubin, albumin). 
Statistical 
Considerations 
(sample size and 
analysis plan): 
The study will enroll up to 15 subjects with the aim for 13 
evaluable subjects to complete the study.  
Sponsors (federal, 
state, foundation 
1. National Institute of Child Health and Human 
Development;  

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and industry 
support): 
2. National Center for Advancing Translational 
Sciences; 
3. Retrophin, Inc. will provide the study drug (cholic 
acid, Cholbam®).  
1.1 Overview 
 
Brief Summary 
The purpose of this study is to determine whether dietary cholic acid therapy benefits 
subjects with Smith-Lemli-Opitz syndrome (SLOS) by leading to an increase in serum 
cholesterol and reduction in cholesterol precursors.  
 
Detailed Description 
People with SLOS have a deficiency of the 7-dehydrocholesterol reductase enzyme that 
makes cholesterol. Consequently, they exhibit deficient serum cholesterol levels and 
increased cholesterol precursor lipids, which are thought to be toxic. Since cholesterol is 
necessary for production of bile acids in the liver, which help digest dietary cholesterol 
from the intestine, it is likely that bile acids are not made properly and dietary cholesterol 
is not absorbed properly. This contributes to the cholesterol deficiency seen in SLOS. 
Raising serum cholesterol in SLOS subjects is expected to decrease the potentially toxic 
cholesterol precursor lipids, and both changes would be theoretically beneficial for 
affected subjects.  
 
Objective: The objective of this study is to determine whether treatment with cholic acid 
(a major bile acid drug used to improve fat absorption) will increase dietary absorption of 
cholesterol, reverse serum cholesterol deficiency, and reduce harmful cholesterol 
precursor lipids. These changes would be favorable for SLOS patients. To accomplish 
this objective, SLOS subjects will be given cholic acid for 2 months and serum cholesterol 
and its precursor lipids will be measured before and while taking the drug.  
 
Target Population: SLOS patients who are ages 2 to 28 years old at time of enrollment 
and are taking supplemental dietary cholesterol will be enrolled. Subjects must be 
clinically stable, have a serum cholesterol ≤125 mg/dl, and be able to travel to a study 
site. No change in supplemental dietary cholesterol intake will be allowed during the 
study, and dietary records will be obtained throughout the study. 
 
Study Protocol: Subjects will be treated with cholic acid, either orally or via gastrostomy 
tube, daily for 8 weeks. Blood will be collected at enrollment (week-0), and cholic acid will 
be started once the cholesterol level is shown to be ≤125 mg/dL. Blood for research tests 
will be obtained at week-0 and week-8 of cholic acid treatment, and 4 weeks off cholic 
acid (week-12).  An additional blood collection for safety labs only will take place every 4 
weeks (week-0, week-4, week-8 and week-12), either at a STAIR site or locally as an 
option for subjects who live distantly from a STAIR site.  

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2. Specific Aims (Hypothesis and Objectives) 
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder associated with 
multiple congenital anomalies, intellectual disability, failure to thrive, and behavioral 
changes. It has an estimated prevalence of 1/20,000 to 1/40,000. Patients with SLOS 
have deficiency of 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes 
the last step in the cholesterol synthesis pathway. Consequently, cholesterol levels are 
low and precursor sterols accumulate. Since cholesterol is the initial substrate for bile acid 
synthesis, it is likely that bile acid production is low and dietary cholesterol is not efficiently 
absorbed, adding to the overall cholesterol deficiency seen in this disease. The symptoms 
of SLOS are thought to be a result of systemic cholesterol deficiency and accumulation 
of sterol precursors. Although dietary cholesterol supplementation is considered the most 
rational approach to treatment of SLOS, dietary cholesterol has a limited effect on serum 
cholesterol levels of many patients, suggesting that it is not efficiently absorbed from the 
diet.  
 
As the already impaired absorption of dietary cholesterol is compounded in part by 
deficient bile acid production, we hypothesize that administering cholic acid (Cholbam®, 
Retrophin, Inc) orally or by a gastrostomy tube to SLOS subjects with low serum 
cholesterol will result in an increase in serum cholesterol and a decrease in the precursor 
metabolites 7- dehydrocholesterol (7-DHC) and 8- dehydrocholesterol (8-DHC).   
 
Our objective is to examine whether cholic acid therapy has efficacy for improving the 
sterol abnormalities in SLOS. This will be determined by achieving the following Specific 
Aims: 
 
Specific Aim 1: We will examine whether cholic acid treatment has the ability to raise 
serum cholesterol and lower its precursors (7-DHC and 8-DHC) in SLOS subjects who 
are on dietary cholesterol supplementation. 
 
Specific Aim 2:  We will examine the effect of cholic acid supplementation on levels of 
serum bile acid and oxysterols, (the toxic products of oxidation of 7-DHC and 8-DHC). 
 
Specific Aim 3: We will explore the safety of short-term cholic acid therapy in the SLOS 
population. 
 
Outcome: Results of this pilot study are expected to establish whether cholic acid has 
biochemical efficacy for improving the sterol abnormalities in SLOS. If so, these results 
will provide a rationale for pursuing future investigations on the long term clinical efficacy 
of cholic acid in this disease.  
3. Background 
Patients with Smith-Lemli-Opitz Syndrome (SLOS), an autosomal recessive disorder 
associated with intellectual disability, congenital malformations, failure-to-thrive and 
behavioral challenges, have a defect in the final step of cholesterol biosynthesis, resulting 
from mutations in the gene for 7-dehydrocholesterol reductase (DHCR7). Patients with 
SLOS demonstrate both cholesterol deficiency and elevation of the precursors 7- 

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dehydrocholesterol (7-DHC) and 8-dehydrocholesterol (8-DHC) (See Figure 1)(1-3).The 
many medical issues seen in patients with SLOS are thought to arise from the cholesterol 
deficiency, the down-stream depletion of cholesterol metabolic products, and the 
accumulation and oxidation of the metabolic precursors into neurotoxic substances called 
oxysterols(4,5). Thus, therapeutic approaches to SLOS include reversing the cholesterol 
deficiency to allow its normal utilization for downstream biosynthetic reactions, and 
reducing toxic 7-DHC and 8-DHC precursors and oxysterols(6,7). 
 
Cholesterol supplementation whether via dietary means (egg yolk), cholesterol powder, 
or with soy-based or aqueous suspensions leads to an increase in serum cholesterol 
levels and a reduction in harmful precursors. Raising cholesterol levels allows cholesterol 
to be available for physiologically important roles including bile acid production, cortisol 
synthesis, RBC membrane stability, and brain growth. Although SLOS is listed as a 
treatable metabolic disorder causing intellectual disability(8), the complex clinical benefits 
of cholesterol supplementation in SLOS remain to be demonstrated in rigorously 
controlled intervention trials. 
 
Treatment with antioxidants has been proposed to reduce the formation of toxic 
oxysterols, which cause neuronal apoptosis and retinal degeneration in an animal model 
of DHCR7 deficiency(9). Moreover, antioxidant therapy has been reported to improve 
retinal function on serial electroretinograms in some SLOS patients(10). Another 
therapeutic option which has been proposed in SLOS is the use of simvastatin to inhibit 
the cholesterol biosynthetic pathway and lower cholesterol precursors. Two studies 
reported that simvastatin was effective in reducing the plasma levels of 7-DHC, but 
neither one reported significant clinical improvement(11,12). There is no reported evidence 
that Simvastin or other drugs which lower plasma levels of cholesterol precursors, affect 
brain levels of cholesterol or precursors. Thus, to date, there is no definitive treatment for 
SLOS and new therapies are sorely needed. Patients are routinely put on cholesterol 
supplementation as standard of care and often take multivitamin-mineral supplements 
with antioxidants. Therefore, any new therapeutic option will have to be tried in patients 
already supplemented with cholesterol and antioxidants. 
 
In this study, we will investigate the efficacy of cholic acid, a bile acid produced from 
cholesterol, to improve intestinal cholesterol absorption, increase cholesterol levels and 
reduce production of toxic cholesterol precursors in patients with SLOS who are on 
cholesterol supplementation.  
 
Cholesterol is a major lipid component of cellular membranes and the precursor to steroid 
hormones, neurosteroids and bile acids. Through its covalent modification of Sonic 
Hedgehog, cholesterol is also critical for certain cell signaling pathways that function in 
fetal and postnatal development. Cholesterol synthesis is highly regulated by feedback 
inhibition of the early rate-limiting step in cholesterol biosynthesis catalyzed by HMG-CoA 
reductase (See Figure 1). Under physiologic circumstances, changes in cholesterol levels 
result in compensatory variations in HMG-CoA reductase activity and bile acid 
biosynthesis, with bile acids playing a major positive role in intestinal cholesterol 

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absorption and HMG-CoA reductase controlling the synthesis of intracellular cholesterol 
precursors (mevalonate).  
 
 
 
Figure 1. Abbreviated biochemical pathway for cholesterol metabolism. Dashed arrows indicate regulatory 
relationships for feedback inhibition of cholesterol synthesis or stimulation of dietary cholesterol absorption. 
 
Patients with SLOS have deficiency of DHCR7, an enzyme that catalyzes the last step in 
the cholesterol synthesis pathway (See Figure 1). As noted above, low cholesterol levels 
should trigger a compensatory increase in HMG-CoA reductase, mevalonate synthesis 
and endogenous cholesterol synthesis to restore cholesterol homeostasis. In SLOS, 
however, the expected compensatory increase in HMG-CoA reductase is not observed, 
probably because cholesterol precursors such as 7-DHC and 8-DHC, and perhaps other 
precursors accumulating as a result from DHCR7 deficiency, substitute for cholesterol in 
down-regulating HMG-CoA reductase, thus maintaining a normal HMG-CoA reductase 
activity despite low cholesterol levels.   
 
In individuals with intact functional cholesterol homeostasis (biosynthesis and dietary 
intake), approximately 50% of dietary cholesterol is absorbed. In SLOS, absorption of 
dietary cholesterol may be further compromised due to impaired bile acid synthesis, thus 
contributing to overall cholesterol deficiency. Individuals with SLOS can exhibit reduced 
production of bile acids(13,14). But in spite of near total deficiency of normal bile acids in 
some patients, clinically evident fat malabsorption and fat-soluble vitamin deficiencies 
may be rare(15). Further, mildly affected individuals have normal bile acid synthesis(16). It 
is thus likely that clinically significant bile acid deficiency that would result in impaired 
cholesterol absorption may be limited to severely affected SLOS patients with very low 
cholesterol levels. Nevertheless, bile acid therapy to directly improve cholesterol intestinal 
absorption, whether an underlying bile acid synthesis deficiency exists or not, appears to 
be a viable therapeutic option for improving whole body cholesterol pool size. 
Cholesterol
Bile Acids
Dietary
Cholesterol
7(8)-Dehydrocholesterol
HMG-CoA
Mevalonate
Oxysterols
DHCR7
HMG-CoA Reductase
+

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Bile acid supplementation in SLOS was used in the mid 1990’s along with cholesterol to 
promote improved cholesterol absorption. Because these early trials with cholic acid were 
performed soon after the metabolic error in cholesterol biosynthesis causing SLOS was 
first identified, there is no published evidence regarding effects of cholic acid on clinical 
course. However, cholic acid was well tolerated, and its use in addition to cholesterol 
supplementation led to an increase in cholesterol levels. Due to the decision to cease 
manufacturing cholic acid, it became unavailable since the late 1990’s. Subsequently, 
ursodeoxycholic acid (Actigall) became the only bile acid that was approved for pediatric 
use and administered to patients with very severe disease (cholesterol levels <30 mg/dL). 
However, long-term use of Actigall led to eventual lowering of cholesterol levels, and thus 
Actigall has not been used chronically to treat patients with SLOS.  Recently, the bile acid 
cholic acid (Cholbam®) has come back on the market. Cholic acid has been shown to 
improve absorption of cholesterol and other important fat-soluble nutrients. There is no 
data available to suggest that long term use of cholic acid might lead to a lowering of 
cholesterol. 
 
In summary, cholic acid treatment may improve intestinal cholesterol absorption in severe 
SLOS patients with impaired bile acid synthesis, and may also be beneficial in less 
severely affected patients with normal or subnormal bile acid synthesis, simply by 
increasing the bioavailability of supplemental cholesterol. Increasing cholesterol 
absorption with cholic acid would secondarily increase the systemic cholesterol level and 
significantly decrease the levels of toxic cholesterol precursors through feedback 
inhibition of the cholesterol biosynthesis pathway. 
4. Study Design and Methods 
This will be an open label, multi-center, pilot study to assess the effects of cholic acid 
administration on serum sterol levels. Up to 15 SLOS subjects will be enrolled with the 
expectation that 13 subjects will complete the study and provide evaluable data. Subjects 
must have a documented serum cholesterol ≤125 mg/dL measured within 6 months prior 
to enrollment to qualify for the study. Informed consent will be obtained prior to completing 
any study procedures. Subjects will be studied in 2 phases (see Figure 2). The first phase 
is a ”Treatment Phase”. Those subjects who have a serum cholesterol ≤125 mg/dL will 
be qualified to be administered cholic acid (Cholbam®, Retrophin, Inc) at 10 mg/kg/day 
dosages given orally or via J- or G-tube divided BID for two months (weeks 0 to 8). This 
dose is based on weight, even in older patients. After completion of the 8-week Treatment 
Phase of the study, cholic acid will be discontinued and subjects will enter the “Post-
treatment Phase” for 4 weeks (weeks 9-12).   
 
We have chosen to perform this trial in patients who fall in the moderate to severely 
affected range, with the hope that this will allow us to see a greater affect of cholic acid 
treatment.  Levels of cholesterol and precursors are associated with severity of disease, 
with those more severe patients showing lower cholesterol levels and higher levels of 
precursors. Although there is some variation in these values based on dietary intake and 
well being of the patients (intercurrent illness can worsen cholesterol deficiency and raise 
precursor levels, for example), these variations are not expected to impact the ability to 
assess affects of treatment. A severely affected patient does not suddenly appear to be 

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mild, and vice versa. We also will be following the Sterol Ratio of precursors divided by 
cholesterol levels, to help assess efficacy of treatment. The ratio does not change to a 
great extent over time. 
 
Due to COVID-19 precautions and potential travel restrictions, we will incorporate 
optional and flexible locations for some site visits. We will adhere to all COVID-19 
precautions established at each STAIR site at the time of each visit.  
 
Figure 2 displays the design of this study, which minimizes COVID-19 risk for subjects 
and healthcare personnel. All subjects will be seen in person for at least two mandatory 
site visits: 1) at the baseline visit (week-0) and 2) at week-8 of the cholic acid Treatment 
Phase. During these mandatory STAIR site visits, subjects will be assessed with physical 
examination, vital signs, growth parameters (weight and height), and laboratory research 
blood specimens and safety blood tests will be obtained. Those subjects who qualify for 
drug treatment, based on a documented serum cholesterol ≤125 mg/dL, will be sent cholic 
acid after their week-0 baseline visit and started on treatment at home. At week-4 and 
week-12, blood will be collected for safety blood tests either at the STAIR site or, 
optionally for those subjects who live distantly from the STAIR site, obtained locally and 
shipped to the STAIR site. In addition, laboratory research blood tests will be obtained at 
week 12 to confirm reversal of sterol levels after discontinuation of cholic acid. For those 
subjects living some distance away from a STAIR site, a telehealth visit will be done at 
the end of week-12, whereas this final visit will be obtained either at the STAIR site or by 
telehealth. In this fashion, safety blood specimens will be collected at weeks 0, 4, 8 and 
12. Research blood specimens will be obtained at weeks 0, 8 and 12. Subjects’ STAIR 
clinic visits and scheduled blood draws must be met within a 5-day time interval.  
 
 
 
Figure 2. Protocol time line. Subjects with mean cholesterol ≤125 mg/dl at their first STAIR site visit will be 
placed into the Treatment Phase and administered cholic acid. Safety lab tests will be monitored while on 
treatment. After 8-weeks, cholic acid will be discontinued and repeat lab tests will be drawn at 12-weeks.  
 
Dietary and Drug Compliance 

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Dietary histories and drug (cholic acid) compliance records will be obtained throughout 
the study. Subjects will be required to maintain their cholesterol supplementation during 
the study. No changes in cholesterol medication will be permitted. Similarly, subjects who 
are taking antioxidants (AquADEKs™ or DEKAs) or other drugs will be required to make 
no changes in dose during the study. To ensure compliance, dietary histories and 
recordings of cholic acid and antioxidant administration will be obtained daily throughout 
the study using a handwritten journal. Using this journal, the subject can record the time 
and amount of the cholesterol supplement, the antioxidant, and the study drug taken daily. 
The caretaker will be asked to scan, photograph and text or fax the dietary information 
from the previous week to the study coordinator at Children’s Hospital Colorado every 
Monday. The study coordinator will contact subjects by telephone on a weekly basis to 
review drug compliance, dietary history, clarify any adverse events or changes in medical 
history.  The Research Dietician at Children’s Hospital Colorado will review 3 days of 
subjects’ dietary histories every week for cholesterol intake. We will ask the study subjects 
to return any remaining cholic acid at the end of the study, as another way to monitor 
compliance.  
 
Using the patient journal, subjects will also be able to report adverse events. The site 
coordinator will review the drug compliance records and contact subjects weekly by 
telephone as needed to clarify adverse events or changes in medical history.  
 
Laboratory Tests 
The following specialized laboratory tests will be performed on fasting (>8 hour) blood 
specimens at weeks 0, 8 and 12: 
  
• Serum cholesterol, 7-DHC, and 8-DHC levels will be measured by Kennedy 
Krieger Institute, in Baltimore, Maryland. The sterol ratio, defined below, will be 
calculated.  
𝑠𝑡𝑒𝑟𝑜𝑙 𝑟𝑎𝑡𝑖𝑜=
[(7 −𝐷𝐻𝐶) + (8 −𝐷𝐻𝐶)]
𝑐ℎ𝑜𝑙𝑒𝑠𝑡𝑒𝑟𝑜𝑙
 
• Serum bile acids (fractionated and total) will be measured by the Metabolic 
Laboratory at Mayo Clinic Laboratories in Rochester, Minnesota. These 
measurements will include total bile acids, cholic acid, and chenodeoxycholic acid.  
• Serum oxysterols will be measured by LC-mass spectrometry at the University of 
Washington in Seattle, Washington. 
• 25-OH vitamin D will be measured at the STAIR study sites. 
 
At the baseline visit, serum cholesterol will be sent to confirm that the subject has a 
cholesterol ≤125 mg/dL prior to beginning cholic acid therapy. All other research blood 
specimens (cholesterol, 7-DHC, 8-DHC, oxysterols, bile acids) will be stored at the STAIR 
clinical sites at approximately -80 ºC and shipped to the reference labs for batch testing.   
 
Safety Tests 
The following tests will be obtained to monitor for safety of cholic acid therapy:  
• CBC with differential and platelet count. 

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• Comprehensive metabolic panel, which includes measurements of renal function 
tests 
(creatinine, 
BUN), 
aspartate 
aminotransferase 
(AST), 
alanine 
aminotransferase (ALT), albumin, alkaline phosphatase, and bilirubin 
• Gamma-glutamyltransferase (GGT). 
 
Safety tests will be obtained at week-0, week-4, week-8 and week-12. Safety lab tests 
will be done immediately and not batched. The subjects’ local lab results will be sent to 
the study PI. Results of these tests will be reviewed by the PI within approximately 3 
calendar days for evidence of abnormalities. If insufficient blood is obtained from the 
patient for all of the above tests, we will prioritize the safety tests and serum cholesterol 
and cholesterol precursors over serum bile acids, oxysterols and 25-OH vitamin D. 
 
For females of childbearing age (who have begun menstruating), a urine or serum 
pregnancy test will be documented at the start of the study (week 0/ baseline) before 
cholic acid is started and at the end of cholic acid administration (week-8).  
 
Dietary Cholesterol Supplementation and Antioxidants 
We will enroll subjects who are already on a dietary cholesterol supplementation. The 
form of cholesterol supplementation may include all available forms of cholesterol 
supplements such as dietary cholesterol in the form of egg yolk, SLOesterol, (an 
encapsulated cholesterol powder developed by Solace Nutrition), SONIC cholesterol (a 
product offered by New Beginnings), an aqueous solution provided by Johns Hopkins 
(150mg/ml), and a concentrated suspension of cholesterol in soy oil (200 mg/ml), 
compounded by a licensed pharmacy collaborating with Dr Elias. The amount of 
cholesterol supplementation will vary among subjects, but generally, subjects are 
expected to be taking cholesterol supplements at 50-150 mg/kg/day. To prevent dietary 
dependent changes in cholesterol status, no changes in the amount or frequency of 
dietary cholesterol taken during this study is allowed. A change in cholesterol intake 
greater than 20% based on dietary history will trigger review and contact with the subject.  
 
It is expected that some subjects will be taking antioxidants, either in the form of 
AquADEKs (Actavis, Inc), available as a liquid suspension, chewable tablet or capsule, 
or a new comparable form called DEKAs Plus (Callion Pharma).  The amount 
administered is based on age and weight of the subject. If taking antioxidants upon 
enrollment, no changes will be allowed in the antioxidant dose during this study. 
 
Study Outcome Measures 
Primary Outcome Measures: One primary outcome measure for this biochemical study 
will be total serum cholesterol, 7-DHC and 8-DHC, and the sterol ratio. It is hypothesized 
that serum cholesterol will rise and 7-DHC and 8-DHC levels will decrease. Either of these 
changes will result in a decrease in the sterol ratio. A second primary outcome measure 
is the incidence of adverse events.  
 
Secondary Outcome Measures: A secondary outcome measure will be oxysterol level. 
The expectation is that oxysterols, which are produced from 7-DHC and 8-DHC, will 
decrease on cholic acid therapy. 

RDCRN Protocol STAIR 7012        Cholic acid Therapy in SLOS         Version date 21Sept2020 
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Exploratory Outcome Measures: These will include serum vitamin D, bile acid levels, and 
changes in safety monitoring including liver function as determined by serum 
transaminases, bilirubin, albumin, alkaline phosphatase, GGT and CBC.  
 
Phlebotomy Estimate: The following blood tests (and requisite maximum blood 
volumes) will be drawn: 
• Comprehensive chemistry panel   
 
2 ml (max) 
• Complete blood count (CBC)  
 
 
3 ml (max) 
• Cholesterol, 7-DHC and 8-DHC   
 
2 ml 
• Bile acids  
 
 
 
 
 
1 ml 
• 25-OH Vitamin D  
 
 
 
 
1 ml 
• Serum gamma glutamyltransferase (GGT)  
1 ml 
• Oxysterols   
 
 
 
 
2 ml 
o Total volume  
 
           
12 ml 
The maximum amount of blood to be drawn for this study is 12 ml/visit x 4 visits/subject, 
or total 48 ml blood over a period of 12 weeks. The age range for subjects is 2-25 years. 
The body weight of a 2-year old child with SLOS ranges between 6 and 10 kg with 8 kg 
being the 50th percentile(17). Assuming a body weight of 8 kg and a 12-ml collection of 
blood at 0, 4, 8 and 12 weeks, the total volume of blood collected over 12 weeks (48 ml) 
will be less than that the NIH Clinical Center research limit of 7 ml/kg/6 weeks. Efforts are 
generally made in Children’s Hospitals to use small size specimens so that the amount 
of specimen required for a blood count and chemistries can be significantly reduced using 
“microtainers” in the lab. For example, the combination of a CBC, CMP and GGT would 
be only 1.6 ml, and it is possible to do the Chol/7-DHC and 8-DHC in only 1 ml. Older 
subjects in this protocol will have proportionally less blood volume taken. Therefore, the 
amount of blood taken for this protocol is well within the established safety limits and 
should cause no anemia or other complications. 
 
Cholic Acid 
Cholic acid (brand name Cholbam®, available from Retrophin, Inc.) is a natural bile acid 
synthesized in the liver and secreted in bile. It is a white or off-white powder that is 
supplied in 50 mg and 250 mg two-piece gelatin capsules. It should be stored at room 
temperature (69º – 77º  F).  
 
Cholbam® is approved by the FDA for the treatment of bile acid synthesis disorders due 
to single enzyme defects (SEDs) and for adjunctive treatment of peroxisomal disorders 
including Zellweger spectrum disorders (ZSD) in patients who exhibit manifestations of 
liver disease, steatorrhea or complications from decreased fat soluble vitamin absorption. 
Owing to their inherited defect in cholesterol and bile acid synthesis, SLOS subjects are 
considered to be SEDs. The recommended dosage of Cholbam® is 10 to 15 mg/kg 
administered orally once daily, or in two divided doses, in pediatric patients and in adults.  
 
Cholic acid is a primary bile acid synthesized from cholesterol in the liver. Bile acids 

RDCRN Protocol STAIR 7012        Cholic acid Therapy in SLOS         Version date 21Sept2020 
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facilitate fat digestion and absorption by forming mixed micelles, and facilitate absorption 
of fat-soluble vitamins in the intestine. Endogenous bile acids including cholic acid 
enhance bile flow and provide the physiologic feedback inhibition of bile acid synthesis. 
Cholic acid enhances absorption of lipids from the intestine and has additional metabolic 
effects. The loss of cholic acid is normally compensated by increased de-novo synthesis 
of cholic acid from cholesterol to maintain the bile acid pool in healthy subjects. In patients 
with SLOS, this compensation mechanism is expected to be disrupted due to the impaired 
synthesis of cholesterol.  
 
Cholbam® should be taken with food. For subjects who are unable to swallow the 
capsules, the capsules can be opened and the contents mixed with infant formula or soft 
food such as mashed potatoes or apple puree (for older children and adults) in order to 
mask any unpleasant taste. Many of the more severely affected patients to be enrolled in 
this study are fed via G-tube which will obviate the taste issue. One of the reasons for 
picking patients >2 years of age is to simplify the dosing calculation as the patients will 
not be that tiny. Cholbam comes in 2 sizes of capsule, so that we can use the smaller 50 
mg capsule in the smaller patients.  
 
On entering the treatment phase of the trial, the parents/ caregivers will be trained at the 
STAIR clinical site in preparing and administering the medication using the aliquot method 
for those subjects who are unable to swallow capsules and must be administered cholic 
acid as a liquid. A study staff member will directly observe each caregiver to certify that 
the caregiver can accurately prepare and administer the correct dose of the study drug 
without assistance. Using video conferencing (such as FaceTime, Skype or Zoom), a 
study staff member will observe the caregiver prepare and administer the study drug 
correctly at least 1-3 times or until the study team is assured that the family members are 
able to administer accurate dosing.  
 
4.1 Inclusion Criteria 
SLOS subjects with the following characteristics will be enrolled: 
1. Ages 2-28 years at enrollment.  
2. Subjects (or their parents/legally-authorized representative) must provide signed 
informed consent. 
3. Assent must be obtained from those subjects ages 7-17 years (or 7-18 years, for 
some STAIR sites) who are intellectually capable of understanding this study.  
4. Diagnosis of SLOS based on clinical features and biochemical/genetic 
confirmation. 
5. Subjects are capable of traveling to the STAIR study site.  
6. Fasting serum cholesterol ≤125 mg/dL within the prior 6 months must be 
established before enrolling in the study. This level of cholesterol will be confirmed 
at the first STAIR visit prior to starting cholic acid therapy.  
7. Clinically stable at the time of enrollment (see below for definition of clinical 
conditions which would preclude enrollment) 
8. Subjects must be on a constant dietary cholesterol intake for at least 3-months 
prior to treatment with cholic acid.  

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9. Subjects must agree to make no changes in cholesterol supplementation during 
the STAIR study. 
10.  SLOS subjects who are taking antioxidants or drugs for neurologic/psychiatric 
symptoms may be included if they agree to make no changes in the medication 
dose during this study. 
11.  Subjects must have internet access and computer (or tablet, smart phone) to allow 
telehealth visits and/or observation of drug preparation.  
4.2 Exclusion Criteria 
Subjects with the following characteristics are excluded from this study:  
1. Subject has an unstable clinical condition that, in the judgment of the principal 
investigator, would prevent completion of the study. Medically unstable patients 
would include those patients with severe liver disease, those patients with complex 
birth defects such as severe heart disease or renal dysplasia, those patients with 
severe respiratory compromise requiring tracheostomy, or patients not likely to 
survive longer than 1 year.  
2. Subject has transaminase elevations (>3-fold above the reference range) at 
baseline. 
3. Subject is taking drugs (statins, bile acid sequestrants, ezetimibe) or nutraceuticals 
(red yeast rice, phytosterols, polycosanol, high dose omega-3 fatty acids) that are 
known or suspected to lower serum cholesterol levels. 
4. Subject is pregnant.  
4.3 Recruitment of Participants 
SLOS subjects will be recruited from each of the STAIR sites listed in Participating 
Institutions/Investigators. Most subjects will be already known to the site PIs and followed 
in their centers. We will also recruit subjects with the assistance of the Smith-Lemli-
Opitz/RSH Foundation and their website, and families will be notified of this study at the 
annual SLOS Foundation Family Conference. The study will be posted on 
www.clinicaltrials.gov. Finally, we may advertise the study to medical geneticists at the 
national meetings of the American Society of Human Genetics and American College of 
Medical Genetics. 
4.4 Retention Strategies 
Retention of subjects in the study will be encouraged by conducting weekly telephone 
calls and promptly addressing any issues, complications or adverse events that may 
arise. Also, to encourage retention, efforts will be made to reimburse costs for travel 
expenses and hotel accommodations for subjects for their STAIR site visits.  
4.5 Data Elements 
Every individual who provides consent will be assigned a unique numerical identifier that 
will ensure anonymity throughout the study. Study personnel at each STAIR site who 
interact with the subject will know them by name and have access to their HIPAA 
identifiable data, however this information will not be shared with the entire study 
personnel group. Each STAIR site that enrolls subjects will upload anonymous subject 
data into a REDCap database that is maintained by the DMCC.  

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4.6 Schedule of Events 
The schedule of event for this study is shown in the Table 1.  
 
Table 1: Schedule of Events 
 
 
Phase: 
 
Treatment 
Post-
Treatment 
Visit Site: 
STAIR 
Local (or 
STAIR) 
STAIR 
Local (or 
STAIR) 
Timepoint: 
Week  
0  
Baseline 
Week 4** 
Week 8 
Week 12 
Assessment  
 
± 5 days 
± 5 days 
± 5 days 
Eligibility and 
Written Consent 
X  
  
  
  
Demographics 
X  
  
  
  
Physical Exam  
X 
X 
Medical History 
X 
  
  
  
Concomitant 
Medications 
X 
X  
 X 
 X 
STAIR Site 
Labs/Local Labs* 
X  
X 
X 
X 
Dietary History 
X 
X 
X 
X 
Teaching and 
observation of 
drug preparation 
X 
 
 
 
Pregnancy Test 
X 
 
X 
 
Weekly phone 
calls 
Inquire about AEs, dietary history recordings, change in 
medications, etc. 
Adverse Events 
Reporting 
Will be included in weekly phone calls. 
Patient-Reported 
Dietary History 
This data will be collected daily and analyzed weekly 
* These labs will be drawn at the STAIR site or locally for subjects. 
** Note that weeks 4, 8 and 12 refer to time after the start of cholic acid therapy. 
 
5.0 Data and Safety Monitoring Plan 
The study protocol will be reviewed and approved by the NIH before submission to the 
STAIR IRB of Record for approval. Participant enrollment may only begin with IRB 
approved consent forms.  
 
Adverse events (AEs) will be recorded from each subject on a weekly basis by the local 
clinic coordinators at each study site. This will be done at routinely scheduled weekly 
telephone calls and include all contact initiated by the subjects themselves. AEs will 
include medical illnesses, change in medical condition, suspected side effects of cholic 
acid, complications of phlebotomy, etc. AEs will be reported to the Study Chair who will 
review them weekly. The Medical Review Officer and Study Chair, together with input 

RDCRN Protocol STAIR 7012        Cholic acid Therapy in SLOS         Version date 21Sept2020 
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from the study site PIs, will decide whether AEs rise to the level of seriousness or unusual 
character or frequency as to suspend the study.  
 
In addition, this study will be reviewed every 6 months by the UNMC Data Safety 
Monitoring Board (DSMB) for safety concerns, complicating issues, and study progress.   
 
5.1 Study Oversight 
The Study Chair (Dr. Ellen Roy Elias) has primary oversight responsibility of this clinical 
trial. The UNMC appointed Data Safety Monitoring Board (DSMB) has oversight 
responsibility of the Data Safety Monitoring Plan (DSMP) for this clinical trial. The DSMB 
will review accrual, patterns and frequencies of all adverse events, and protocol 
compliance every 6 months. The DSMB makes recommendations to the NIH regarding 
the continuation status of the protocol. 
 
Each site’s Principal Investigator and their research team (co-Investigators, research 
nurses, clinical trial coordinators) are responsible for identifying adverse events. 
Aggregate report detailed by severity, attribution (expected or unexpected), and 
relationship to the study drug/study procedures – will be available from the DMCC for site 
review.  Adverse events will be reviewed monthly by the research team.  A separate report 
detailing protocol compliance will also be available from the DMCC for site review on a 
monthly basis. The research team will then evaluate whether the protocol or informed 
consent document requires revision based on the reports. 
5.2 Definitions and Standards 
An adverse event is defined as: “…an unfavorable and unintended sign, symptom or 
disease associated with a participant’s participation in a study.” 
 
Serious adverse events include those events that: “result in death; are life-threatening; 
require inpatient hospitalization or prolongation of existing hospitalization; create 
persistent or significant disability/incapacity, or a congenital anomaly/birth defects.”  
 
An unexpected adverse event is defined as any adverse experience…the specificity or 
severity of which is not consistent with the risks of information described in the protocol.  
 
Expected adverse events are those that are identified in the research protocol as having 
been previously associated with or having the potential to arise as a consequence of 
participation in the study 
 
All reported adverse events will be classified using the current version of the Common 
Terminology Criteria for Adverse Events (CTCAE) developed and maintained by CTEP 
at National Cancer Institute. 

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5.3 Expected/Known Risks/Discomforts/Adverse Events Associated with 
Study Intervention and Procedures: Definition of Expected Adverse 
Events 
The risks of cholic acid therapy in SLOS are expected to be low, in part due to the 
endogenous nature of cholic acid which is normally made in the liver and excreted into 
the intestine. Based on the 3 studies in patients with single enzyme defects (SED) of bile 
acid synthesis and Zellweger syndrome spectrum disorders (ZSD), diarrhea was 
identified as the most frequent AE, occurring in 2% of this population. In addition, the 
following AEs were noted at frequencies of 1% or less: reflux esophagitis, malaise, 
jaundice, nausea, abdominal pain, intestinal polyp, skin lesions, urinary tract infections 
and peripheral neuropathy. In this population, cholestasis and liver dysfunction was seen 
in 58/79 (86% of patients). Five patients exhibited worsening liver function on cholic acid. 
Five additional patients without liver dysfunction at the time of cholic acid initiation 
developed liver dysfunction on the drug. In contrast to SED and ZSD, SLOS is not usually 
associated with liver disease, although some SLOS subjects do have mildly elevated 
serum transaminases. Consequently, it is not expected that cholic acid therapy will lead 
to liver related AEs. Nevertheless, safety monitoring for worsening of the liver will be done 
at least monthly and more frequently if clinically indicated.  
 
Risks of Phlebotomy:  
• 
Procedure and risks: In general, phlebotomy is considered to carry a very low risk of 
complications. Venous blood is typically removed from an accessible site such as the 
arm using a small needle. Blood drawing will cause some mild temporary pain and 
carries a small risk of bleeding, bruising and/or infection at the puncture site.  
• Protections from risk: To decrease discomfort of the needle poke in children, we will 
use topical anesthetic EMLA cream applied to the skin 30 minutes in advance of the 
procedure. To minimize associated risks of bleeding and bruising, only experienced 
phlebotomists will draw blood for our studies. Bleeding and bruising at the puncture 
site is usually easily controlled with the application of direct pressure and a bandage. 
Bruising at the puncture site is occasionally seen, but is not harmful. Using standard 
phlebotomy procedures with sterilization of the skin and gloved personnel, infection 
from routine venous phlebotomy is exceedingly rare. It can be treated effectively with 
antibiotics, if necessary. The minimal amount of blood necessary to carry out our 
STAIR studies will be collected. We will not exceed 7 ml of blood/kg body weight per 
6 weeks, which is considered safe in children and will not cause anemia or related 
symptoms. 
5.4 Reporting Timeline 
• Within 24 hours of learning of any Serious Adverse Event (SAE), investigators must 
report it to the study PI and DSMB if it:  
o 
Is considered life-threatening/disabling or results in death of subject 
-OR- 
o 
Is Unexpected/Unanticipated  
• Investigators must report all other reportable SAEs within 5 working days (of learning 
of the event). 

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• All other (suspected) reportable AEs must be reported to the DSMB within 20 working 
days of the notification of the event or of the site becoming aware of the event. 
5.5 RDCRN Adverse Event Data Management System  
Upon entry of a serious adverse event, the DMCC Data Management system will 
immediately notify the Study Chair, site PIs, and any additional agencies (if applicable- 
industry sponsor, CTEP, etc) of any reported adverse events via email.  
 
Serious adverse events: The Medical Review Officer (MRO) determines causality 
(definitely not related, probably not related, possibly related, probably related, definitely 
related) of the adverse event. The MRO [and Retrophin] may request further information 
if necessary and possibly request changes to the protocol or consent form as a 
consequence of the adverse event. A back-up notification system is in place so that any 
delays in review by the MRO beyond a specified period of time are forwarded to a 
secondary reviewer. The DMCC REDCap system maintains audit trails and stores data 
(and data updated) and communication related to any adverse event in the study.  
 
Non-serious expected adverse events: Except those listed above as immediately 
reportable, non-serious expected adverse events that are reported to or observed by the 
investigator or a member of his/her research team will be submitted to the DMCC in a 
timely fashion (within 20 working days). The events will be presented in tabular form and 
given to the MRO and UNMC DSMB on a bi-annual basis. Local site investigators are 
also required to fulfill all reporting requirements of their local institutions. 
 
The DMCC will post aggregate reports of all reported adverse events for site 
investigators. 
5.6 Study Discontinuation  
The NIH and local IRBs (at their local site) have the authority to stop or suspend this trial 
at any time. This study may be suspended or closed if: 
• Early stopping rules have been met. 
• Accrual has been met. 
• The study objectives have been met. 
• The Study Chair / Study Investigators believe it is not safe for the study to continue. 
• The DSMB recommends suspending or closing the trial 
• The NIH suspends or closes the trial. 
• The FDA suspends approval of Cholbam for human use. 
• Retrophin withdraws use of Cholbam. 
 
Premature discontinuation of this study will also occur under the following circumstances: 
• Adverse events (AEs) are determined to occur in a significant proportion of 
subjects or the AEs are serious enough that the subjects are judged to be at high 
medical risk if participation in the study continues. An adverse event would include 
hospitalization, or marked worsening liver function or GI symptoms severe enough 
to prevent the patient from taking the cholic acid. 

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• Failure to retain subjects and complete the study. 
The study involves treating SLOS subjects with cholic acid. For this purpose, AEs will be 
reviewed by the Medical Review Officer and DSMB to determine if the AE is  related to 
the drug.  
 
5.7 Subject Withdrawal and/or Cholic Acid Dose Interuption/Reduction 
The following conditions will result in withdrawal of the subject from the study: 
• Withdrawal of consent 
• Withdrawal by the participant 
• Withdrawal by the investigator 
• Intercurrent illness or event that precludes further visits to the study site or ability 
to evaluate disease (e.g.-mental status change, serious illness, pregnancy).  
 
Withdrawal from the study will be permitted at any time with the agreement of the Principal 
Investigator and/or SLOS subject (or parent/legal authorized representative). Withdrawal 
may be necessitated for clear evidence of non-compliance, adverse effects of the drug, 
onset of concurrent illness, or new SLOS complication that prevents continuation. All data 
acquired prior to termination for the reasons outlined below will be included in the primary 
analysis unless the subject provides a written request to delete all of their data from the 
data base and subsequent analyses. Every effort will be made to conduct a final study 
visit with the participant and participants will be followed clinically until, if applicable, all 
adverse events resolve. 
 
Cholic Acid Dose Reduction 
1. During the Treatment Phase, administration of cholic acid may be interrupted for up to 
3 successive days if the subject develops an acute illness and cannot tolerate the drug, 
for example due to vomiting or diarrhea. Interruption of drug for a longer period of time 
(>5 days) may trigger withdrawal from the study, upon review and agreement by the 
Principal Investigator and site investigators or the Medical Review Officer. 
 
2. In addition to a temporary complete interruption of cholic acid administration, evidence 
of worsening liver function may prompt a reduction in drug dosage. Worsening of liver 
function is defined as: 
• AST, ALT and/or GGT >3 times above baseline measurements or >300 IU in any 
patient and/or 
• A total bilirubin value >3 mg/dL (if the baseline level is <10)  and/or 
• onset of serious gastrointestinal symptoms not clearly associated with a limited 
infectious illness 
Worsening of liver function will trigger a review by the Prinicipal Investigator and reduction 
of cholic acid dosage to 5 mg/kg/day. Monitoring labs will be obtained 1 week after 
lowering the dose. If the subject does not tolerate this lower dose, based on symptoms 
or persistently abnormal test results, the subject may be withdrawn from the study.  

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5.8 Data Quality and Monitoring Measures 
As much as possible data quality is assessed at the data entry point using intelligent on-
line data entry. Data element constraints, whether independent range and/or format 
limitations or ‘relative’ referential integrity limitations, can be enforced by all methods 
employed for data input. QA reports assess data quality post-data entry. As we note, data 
quality begins with the design of the data collection forms and procedures and 
incorporates reasonable checks to minimize transcription and omission errors. Of the 
more important quality assurance measures are the internal validity checks for 
reasonableness and consistency.  
 
• Data Monitoring: The DMCC identifies missing or unclear data and generates a 
data query to the consortium administrator contact.  
• Data Delinquency Tracking: The DMCC will monitor data delinquency on an 
ongoing basis.   
5.9 Quality Control: Study Related Procedures 
Study related procedures will be outlined in a Manual of Operations (MOO), which will be 
distributed to each of the study sites. The MOO will include descriptions of methods for 
blood collection, processing and storage. Instructions will be included for shipment of 
specimens to the Study Chair for batch shipment to reference laboratories for testing. 
6. Statistical Considerations 
Data from this study will be submitted to the DMCC located at the Cincinnati Children’s 
Hospital & Medical Center. Physical examination, laboratory studies, vital signs, and 
growth parameters assessed at week 0 and week 8 will be tabulated. The difference in 
total serum cholesterol, 7-DHC and 8-DHC, sterol ratio, oxysterol levels, serum bile acids, 
and liver function from the baseline visit (week 0) to week 8 visit will be calculated for 
each participant. The average change and 95% confidence intervals for each of these 
measurements will be estimated.  
 
Safety data will be summarized for all treated subjects using appropriate tabulations, and 
descriptive statistics. The incidence rate of each adverse event will be estimated and 
reported with exact 95% confidence intervals.   
 
Sample size: This pilot study is intended to explore preliminary signals for efficacy as well 
as examine safety of cholic acid supplementation. The primary purpose of the study is to 
detect a difference in pre-and-post treatment mean serum cholesterol level of one group. 
The sample size was based upon a sufficient number of participants to begin such 
explorations prior to pursuit of a randomized controlled trial and historical variation in 
serial serum cholesterol levels in SLOS subjects. We conservatively use the population 
effect size of 0.80 and the significance level (alpha) of 0.05 using a two-sided one-sample 
t-test. With an accrual of 13 evaluable participants, an estimated standard deviation of 5 
mg/dl with mean 61 mg/dl for the cholesterol measurements, a within subject correlation 
of .8 (between pre and post testing) and a two-sided alpha of 0.05, there is greater than 
80% power to detect a change in total serum cholesterol of greater than 10 mg/dl. Under 
the same assumptions, for sterol ratio of 7-DHC/cholesterol, based on a standard 

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deviation of 0.21, there is greater than 80% power to detect a change of greater than 
0.07. To adjust for 15% dropout rate, 15 SLOS patients will be recruited for the study. 
There will be no interim analysis of the data.  
7. Data Management 
The following data will be obtained: 
• Demographics: age (years and months), date of birth, gender. 
• Physical measurements, including vital signs, weight, height, blood pressure. 
• Laboratory: serum cholesterol, 7-DHC, 8-DHC, oxysterols, serum bile acids (total 
bile acids, cholic acid, chenodeoxycholic acid, comprehensive chemistry profile 
(including AST, ALT, bilirubin), GGT and complete blood count (CBC) including 
platelets.  
All study data will be collected via systems created in collaboration with the DMCC and 
will comply with all applicable guidelines regarding patient confidentiality and data 
integrity. 
 
All research data will be collected on data forms and submitted online to the DMCC 
REDCap database. Participant identifiers will be used to protect participant confidentiality 
and safety.  
7.1 Registration 
IRB approval for the protocol must be on file at the DMCC before accrual can occur from 
the clinical site. 
 
The DMCC will use a system of coded identifiers to protect participant confidentiality and 
safety. Each participant enrolled will be assigned a local identifier by the enrollment 
site.  This number can be a combination of the site identifier (location code) and a serial 
accession number.  Only the local site will have access to the linkage between this 
number and the personal identifier of the subject.   
 
7.2 Data Entry 
Data collection for this study will be accomplished with online electronic case report 
forms.  Using encrypted communication links, on-line forms will be developed that contain 
the requisite data fields.   
 
7.3 Laboratory Data Flow 
If possible and practical for this pilot study, the DMCC will provide laboratories with on-
line forms and/or electronic data exchange mechanisms - depending on their capabilities 
and needs - to enter, update and obtain relevant data. Online forms exist to verify 
specimen receipt, report specimen issues and submit test results for specimens. The 
preferred method to exchange data electronically is through the Specimen Management 
System Web Service. The Web Service allows laboratories to obtain specimen shipment 
information, receive individual specimens or specimen shipments, report specimen 
issues and communicate specimen aliquots in a secure manner (test result submission is 

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planned). The DMCC will also support uploading of files electronically.  All transactions 
are logged and validated for both methods. 
7.4 Study Records Retention 
Hard copies of data forms will be stored at each STAIR study site that enrolls subjects. 
Forms will be stored for at least 5 years after completion of the study. 
 
7.5 Protocol Deviations 
Protocol deviations are defined as any significant alteration of the proposed procedures. 
Deviations will be reported to the site PI and recorded. Protocol deviations will also need 
to be reported to the IRB and DMCC. Deviations will include, but are not limited to, the 
following: 
• Failure to obtain proper written consent. 
• Failure to obtain required blood specimens on time (± 5 days).  
• Inadequate administration of cholic acid dose. 
• Failure to return to study site visit on time (± 5 days). 
• Inappropriate specimen collection, change in drug dosing or other data collection.  
8. Human Subjects 
8.1 Good Clinical Practice Statement 
This clinical trial will be conducted in accordance with the ethical principles that have their 
origin in the Declaration of Helsinki, and that are consistent with Good Clinical Practice 
and all applicable regulatory requirements. 
8.2 Benefits 
Subjects will receive no clinical benefit from participating in this study. It is hoped that the 
information learned in this study will be able to help others with SLOS in the future.  
8.3 Risks 
Risks of participating in this study are summarized in Section 5.3 and consist of risks 
associated with cholic acid therapy, phlebotomy and potential loss of confidentiality.  
8.4 Inclusion of Subjects  
Since SLOS is not limited to any particular ethnic minority or socio-economic group or 
gender, we anticipate enrolling any and all subjects who are diagnosed and satisfy the 
inclusion criteria. 
 
Inclusion of children  
Because the majority of subjects with SLOS are children and relatively few adults with 
SLOS are known, we expect that children will be the major group studied. We will recruit 
subjects between 2 years to 28 years of age and of both genders.  
 

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Inclusion of women  
Women and girls will be included in the study. SLOS is an autosomal recessively inherited 
condition that affects males and females equally, so females should be equally 
represented in this study. However, since this disorder is uncommon, STAIR investigators 
will have limited control over the gender mix of the study population. 
 
Inclusion of Minorities  
SLOS affects all ethnic and minority groups. Owing to the rarity of SLOS in the United 
States population, STAIR investigators will have limited control over the race and ethnicity 
mix of the study population. In order to increase the enrollment of minority subjects, we 
will recruit from a national population, so that subjects in all regions of the U.S. with 
ethnically and racially diverse populations may be recruited.  
8.5 Written Informed Consent 
Written informed consent will be obtained from each participant or their parents/ legally 
authorized representative before any study-specific procedures or assessments are done 
and after the aims, methods, anticipated benefits, and potential hazards are explained. 
The participant’s willingness to participate in the study will be documented in writing in a 
consent form, which will be signed by the participant with the date of that signature 
indicated. The investigator will keep the original consent forms and signed copies will be 
given to the participants.  It will also be explained to the participants that they are free to 
refuse entry into the study and free to withdraw from the study at any time without 
prejudice to future treatment. Written and/or oral information about the study in a 
language understandable by the participant will be given to all participants. 
Assent will be obtained from children ages 7-17 years (7-18 years for subjects studied in 
the Nebraska STAIR site). Written assent forms will be provided using age appropriate 
language. It is recognized that most subjects with SLOS have intellectual disability and 
may not be capable of providing informed assent. We will therefore rely on the judgment 
of the child’s parents/guardian/legal authorized representative for guidance concerning 
their ability to fully comprehend this study and provide assent. 
8.6 Process of Consent   
Informed consent will be obtained in one of the following manners. Those SLOS subjects 
who are routinely followed at one of the STAIR sites will be notified of the study at the 
time of their clinic visit or by telephone. Informed consent will be obtained from the parent 
and/or subject’s legally-authorized representative (LAR) in the clinic setting. Ample time 
will be given for the parent/LAR to review the study information and provide written 
consent.  
Alternately, since some SLOS subjects are located throughout the United States, initial 
contact concerning enrollment will be made with the parents and/or LAR by telephone. 
The study will be described in detail and any questions addressed at the time of initial 
contact. Parents/LARs will be mailed the consent forms to review. A follow up telephone 
contact will be made to clarify any additional questions about the study. Parents/LARs 
who provide verbal assent for enrollment of their child will be asked to travel to the STAIR 

RDCRN Protocol STAIR 7012        Cholic acid Therapy in SLOS         Version date 21Sept2020 
 28 
center, where written consent will be obtained in person.  
8.7 Certificate of Confidentiality 
This research is covered by a Certificate of Confidentiality from the National Institutes of 
Health. The researchers with this Certificate may not disclose or use information, 
documents, or biospecimens that may identify the participant in any federal, state, or 
local civil, criminal, administrative, legislative, or other action, suit, or proceeding, or be 
used as evidence, for example, if there is a court subpoena, unless the participant has 
consented for this use. Information, documents, or biospecimens protected by this 
Certificate cannot be disclosed to anyone else who is not connected with the research 
except, if there is a federal, state, or local law that requires disclosure (such as to report 
child abuse or communicable diseases but not for federal, state, or local civil, criminal, 
administrative, legislative, or other proceedings, see below); if the participant consents 
to the disclosure, including for their medical treatment; or if it is used for other scientific 
research, as allowed by federal regulations protecting research participants.  
 
The Certificate cannot be used to refuse a request for information from personnel of the 
United States federal or state government agency sponsoring the project that is needed 
for auditing or program evaluation by the U.S. Department of Health and Human 
Services and/or the National Institutes of Health, which is funding this project or for 
information that must be disclosed in order to meet the requirements of the Federal 
Food and Drug Administration (FDA).  The Certificate of Confidentiality does not prevent 
a participant from voluntarily releasing information about themselves or their 
involvement in this research. If a participant wants research information released to an 
insurer, medical care provider, or any other person not connected with the research, the 
participant must provide consent to allow the researchers to release it. 
 
Even with the Certificate of Confidentiality, the investigators continue to have ethical 
obligations to report child abuse or neglect and to prevent an individual from carrying 
out any threats to do serious harm to themselves or others.  If keeping information 
private would immediately put the study participant or someone else in danger, the 
investigators would release information to protect the participant or another person.  
The Certificate of Confidentiality will also not be used to prevent disclosure as required 
by federal, state, or local law, such as reports of child abuse and neglect, or harm to self 
or others.  
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rat liver. J Lipid Res. 1999; 40 (8):1520-1528. 
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10. Appendices 
None