The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease: A Pilot Study
Phase: PHASE2
Conditions: NAFLD, Nonalcoholic Fatty Liver, NASH - Nonalcoholic Steatohepatitis
Sponsor: Massachusetts General Hospital

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Identifiers: 
NCT05364684    
Brief Title: 
The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease 
Document Version Date: 08/13/24 
 
 

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Institutional Review Board 
Intervention/Interaction Detailed Protocol 
 
 
Principal Investigator: 
Laura Dichtel, MD, MHS 
 
Project Title: 
The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease 
(NAFLD): A Pilot Study  
 
Version Date: 
08/13/24 
 
 
Version Name/Number: 
Detailed Protocol Version 17 
 
 
For Intervention/Interaction studies, submit a Detailed Protocol that includes the following 
sections.  If information in a particular section is not applicable, omit and include the other 
relevant information.   
 
 
1. 
 Background and Significance 
 
 SIGNIFICANCE OF THE PROBLEM:  
 
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease, with a global 
prevalence of 25%.[1] Nonalcoholic steatohepatitis (NASH) cirrhosis is the second leading 
indication for liver transplantation in the U.S. and will be the top indication by 2025.[2, 3] Despite 
the significant morbidity and mortality, the molecular mechanisms that lead to the development of 
NAFLD and progression to NASH are poorly understood, and there are no FDA-approved 
treatments. As a long-acting, oral ghrelin mimetic, ibutamoren is a direct immunomodulator 
and effective growth hormone (GH) secretagogue. GH, which is reduced in obesity, is a critical 
stimulator of lipolysis,[4] regulator of abdominal fat depots and an important mediator of 
inflammation[5] and immune cell populations.[6, 7] Thus, investigation of ibutamoren 
administration in NAFLD/NASH could lead to insights into the development of NAFLD, 
progression to NASH, and identification of novel therapeutic targets. 
A2. IBUTAMOREN HAS DIRECT IMMUNOMODULATORY EFFECTS:  
Ibutamoren regulates T cell populations involved in the pathogenesis of NAFLD/NASH directly 
through the ghrelin receptor (GHSR1a). One of the characteristic findings in NASH is imbalanced 
CD4 T cell helper activity with a dominance of Th17 signaling compared to regulatory T cells,[8] 
and targeting this balance is a new approach in the treatment of NAFLD.[9] Ghrelin has been 
shown to directly inhibit the differentiation of Th17 cells through the GHSR1a and downstream 
inhibition of mTOR/STAT3 signaling[10, 11] and has the potential to improve this T pathological 
cell imbalance.  
Ibutamoren has the potential to prevent disease progression in NAFLD/NASH through 
additional anti-inflammatory effects via GHSR1a activation in immune cells.[12-14] Ghrelin 
and the GHSR1a receptor are expressed in human T cells and monocytes, and ghrelin activates 
the GHSR1a in these cells to reduce inflammatory cytokines such as IL-6 and TNF-α.[12] 
Additionally, RNA interference-mediated reduction in ghrelin production in human T cells was 
shown to increase production of pathological inflammatory cytokines.[15] The anti-inflammatory 
effects of ghrelin and ghrelin mimetics like ibutamoren have been demonstrated in animal models 
of acute[16-18] and chronic[19-24] inflammation and small human studies of chronic23,25 and post-
operative inflammatory conditions.[25] Ghrelin has also been shown to reduce inflammation with 

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chronic high-fat feeding.[26, 27] Ghrelin reduced inflammation, oxidative stress and apoptosis in 
a mouse model of NAFLD, with activation of AMPK and PI3K/Akt pathways as proposed 
mechanisms that have been implicated in NAFLD/NASH.[27] Finally, ghrelin administration not 
only reduced inflammatory markers but also hepatic triglycerides in a mouse model of high fat 
feeding, suggesting multiple beneficial effects of GHSR1a activation. 
 
A3. IBUTAMOREN AUGMENTS GH RELEASE, WHICH HAS IMMUNE AND LIPOLYTIC 
EFFECTS:  
 
Ibutamoren also regulates T cell populations indirectly through downstream effects of GH 
augmentation. Ibutamoren is also a potent GH secretagogue, and GH is an important regulator 
of Th17 and regulatory T cells. Transgenic overexpression of GH reduces pathogenic TH17 
responses in animal models of rheumatoid arthritis[6] and type 1 diabetes,[7] delaying disease 
onset and severity. Thus, ibutamoren, indirectly via GH, has an additional mechanism for 
amelioration of the pathological Th17 response characteristic of NASH.[8, 9] 
 
GH is also an anti-inflammatory cytokine[28] and an important mediator of inflammation, 
and ibutamoren may have additional indirect anti-inflammatory effects through GH 
augmentation.  The GH receptor is a member of the cytokine receptor family, and GH has 
cytokine-like effects. GH administration decreases hsCRP, a marker of systemic inflammation, 
and other cytokine levels, including IL-6 and TNF-α, in patients with GH deficiency due to both 
pituitary disorders and obesity.[5, 29-31] This may have critical implications for the progression of 
simple steatosis to NASH, as inflammation is a hallmark of disease progression. TNF-α, IL-6 and 
hsCRP have been implicated in the inflammatory milieu causing this progression to NASH,[32] 
and inflammation on initial histology has been associated with a 2.5-fold risk of advanced 
fibrosis.[33]  
 
GH is a critical stimulator of lipolysis,[4] and preclinical data suggest that GH axis 
augmentation has the potential to reduce hepatic steatosis and prevent progression of 
NAFLD. GH signals via the JAK2/STAT5 pathway in hepatocytes.[34] Multiple mouse models 
have demonstrated that hepatocyte-specific knockouts of the GH receptor, JAK2 or STAT5 result 
in a NAFLD phenotype.[35-38] These models demonstrate that loss of GH receptor/JAK2/STAT5 
signaling leads to an increase in PPAR-gamma, which drives the NAFLD phenotype through 
increased hepatic lipid uptake (via increasing CD36, a fatty acid transporter) and upregulation of 
de novo lipogenesis.[38, 39] These data suggest that GH suppresses hepatic lipid uptake and de 
novo lipogenesis in the normal state, and that GH axis augmentation could be a potential 
therapeutic target in NAFLD.  
 
A4. OBESITY IS A STATE OF RELATIVE GH-DEFICIENCY AND POTENTIAL 
THERAPEUTIC TARGET IN NAFLD:  
 
In obesity, pulsatile GH production is reduced by 75%, primarily due to reduced GH pulse 
amplitude, and visceral adiposity is a strong negative determinant of GH secretion.[40, 41] In the 
normal state, hypothalamic growth hormone releasing hormone (GHRH) stimulates the pulsatile 
release of GH by the pituitary gland, leading to hepatic production of insulin-like growth factor-1 
(IGF-1). Clinical GH replacement is delivered via daily injection, while GH secretagogues like 
ibutamoren restore the endogenous pulsatility and feedback loops, restoring the GH/IGF-1 axis 
in a more physiologic manner.  
 
Administration of GH to patients with severe GH deficiency due to hypopituitarism 
improves NAFLD, consistent with an etiopathologic role of GH deficiency. Studies of 
hypopituitary patients with profound GH deficiency have demonstrated a higher rate of NAFLD 
compared to sex, age- and BMI-matched controls (77% versus 12%, respectively, p<0.001), in a 
group where the mean BMI was just above normal (25±4.9 kg/m2). Additionally, administration of 
physiologic GH replacement decreased ALT, AST, hsCRP and markers of fibrosis in a group of 
hypopituitary individuals with GH deficiency, more than half of whom had NAFLD. Histologic 
steatosis score and fibrosis stage improved in a subset (n=5) with pre- and post-GH biopsies.[42] 

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Studies of otherwise healthy, overweight and obese individuals without pituitary disorders 
also implicate relative GH deficiency in the pathophysiology of NAFLD/NASH, and 
preliminary clinical data suggest that restoration of the GH axis in the obesity. In the cross-
sectional Aim of the K23 study, I demonstrated that overweight and obese subjects with NAFLD 
have lower peak stimulated compared to non-NAFLD controls of similar age, BMI and sex. 
Additionally, lower peak stimulated GH was associated with higher intrahepatic lipid content (IHL) 
by proton magnetic resonance spectroscopy (1H-MRS), independent of age, BMI, sex and 
visceral adipose tissue (data in preparation for publication).  
 
Preliminary clinical data suggest that restoration of the GH axis in obesity is a potential 
therapeutic strategy in NAFLD. Our group demonstrated that once daily GH administration by 
subcutaneous injection with an increase in IGF-1 levels to the upper-normal range reduced IHL 
by 1H-MRS in overweight/obese individuals unselected for NAFLD.[29] Of importance, only a 
subset of study subjects would have qualified as having NAFLD. Despite this, we detected a 
decrease in IHL. These pilot data are exciting with regard to the potential for GH augmentation 
as an effective therapeutic strategy in NAFLD. However, studies demonstrate that GH 
pulsatility may be particularly important for effective lipolysis,[43] and that a more 
continuous (versus pulsatile) administration of GH may downregulate GH signaling 
pathways.[44] Thus importantly, in contrast to once daily GH administration, restoration of 
endogenous GH pulsatility via a GH secretagogue like ibutamoren may enhance the lipolytic 
effects of GH[43, 44] while preserving endogenous feedback loops, enhancing both efficacy and 
safety profiles.  
A5. SAFETY AND KNOWN EFFECTS OF IBUTAMOREN:  
Ibutamoren has been studied in >1,200 individuals[45-53] and has been shown to safely and 
effectively augment GH pulsatility.[52, 54] As a GH secretagogue, ibutamoren prevents 
hyperstimulation of the hypothalamic-pituitary axis by preserving rather than overriding 
physiological feedback control. Unlike short-acting ghrelin, ibutamoren does NOT cause 
sustained activation of ACTH and cortisol[52, 55]  and does not cause increases in abdominal 
visceral fat mass.[52] Ibutamoren has been studied in pediatric GH deficiency,[45] healthy aging 
populations (60-81yrs),[46] hip fracture recovery,[47] osteoporosis,[49] Alzheimer’s disease,[50] 
adult hemodialysis patients,[51] and in obesity,[52] with sustained increases in GH and IGF-1 in 
all study groups.  
 
Ibutamoren has been shown to effectively augment GH pulsatility and increase IGF-1 levels 
in obese individuals with restoration of the GH/IGF-1 axis and increase in fat-free mass.[52, 
54] Ibutamoren augments the natural pulsatility of GH in obese individuals to approach that of 
lean individuals.[54] The importance of this is that it more closely approximates a natural hormone 
replacement therapy resulting in the potential for fewer side effects than daily supraphysiologic 
GH injections, for example, with negligible incidence of clinically significant hyperglycemia or 
diabetes.[53] Two months of oral ibutamoren in adults with obesity resulted in a 40% 
increase in serum IGF-1,[52] which is similar to the 50% increase in IGF-1 levels achieved with 
daily, subcutaneous GH administration at 6 weeks in a similar population in our study.[29] A 
significant increase in fat-free mass was seen at 8 weeks. There was no significant change in 
total or visceral fat during the brief, 8-week treatment period. However, change in IGF-1 level with 
ibutamoren was negatively correlated with change in visceral fat volume, suggesting the potential 
for body composition changes over time with longer treatment-duration. Importantly, NAFLD-
specific endpoints have not yet been studied in trials of ibutamoren.  
 
A6. SCIENTIFIC PREMISE AND HYPOTHESIS:  
The proposed intervention, ibutamoren, is an orally administered, long-acting ghrelin mimetic that 
has direct immune effects that target specific areas of known immune dysregulation in 
NAFLD/NASH, physiologically restores endogenous GH pulse amplitude, and has a strong safety 
profile with prior administration in over 1,200 individuals (adults and children).[45-53] Our 
overarching hypothesis is that oral ibutamoren administration will improve steatosis, 
inflammation and fibrosis in subjects with overweight/obesity and NASH. This proposal will 
also provide critical preliminary data regarding the molecular and immunologic mechanisms by 

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which ibutamoren impacts NASH through complementary methods of bulk RNAseq (molecular 
effects on hepatocytes) and scRNAseq (immune cell populations and cellular interactions) for a 
future R01 application.  
 
 
2. 
Specific Aims and Objectives  
 
 
A.  SPECIFIC AIM 1: We hypothesize that GH augmentation by oral ibutamoren for 6 
months in subjects NAFLD compared to an historically studied placebo group 
subjects for 6 months will: 
Aim 1A: Decrease hepatic steatosis, as measured by 1H-MRS (primary 
endpoint) 
Aim 1B: Decrease hepatic inflammation and fibrosis, as measured by 
LiverMultiScan (primary endpoint)  
 
B. SPECIFIC AIM 2: Transcriptomic analyses of liver biopsy specimens pre- and post-
GH augmentation with ibutamoren will define the molecular and immunological 
mechanisms responsible for its therapeutic effect by leveraging complementary 
techniques of bulk and single cell RNAseq in this exploratory aim. 
Aim 2A: We hypothesize that ibutamoren will induce changes in expression of 
genes responsible for lipolysis, fatty acid oxidation, de novo lipogenesis and 
inflammation as demonstrated by bulk RNAseq. Moreover, if there are changes 
identified by bulk RNAseq, single cell RNAseq provides opportunity to identify the 
specific cell populations responsible for observed metabolic and 
immunomodulatory changes.  
Aim 2B: We hypothesize that ibutamoren will induce changes in intrahepatic 
immune cell profiles as demonstrated by single cell RNAseq (SeqWell).  
 
 
3. 
General Description of Study Design 
 
Overview of Study Design (Figure 1, Table 1) 
An overview of the study design is provided in Figure 1. Aim 1 examines the effect of 
Ibutamoren mesylate administration on intrahepatic lipid accumulation in 10 men and women 
with NAFLD and relative IGF-1 deficiency. Aim 2 is a liver biopsy substudy (~50% of subjects 
from Aim 1) that examines the histologic effects and mechanisms of ibutamoren in NAFLD. 
 
This study also investigates potential mediators of GH-induced decrease in intrahepatic lipid 
accumulation, including insulin/glucose and lipids, as well as body composition parameters. 
Ibutamoren will be dosed at 25 mg daily after completion of all baseline tests. 

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Aim 1A investigates the 6-month change in intrahepatic lipid content by 1H-MRS (primary 
endpoint) and AIM 1B investigates the 6-month change in hepatic inflammation and fibrosis by 
LiverMultiScan (primary endpoint) with GH augmentation by ibutamoren versus historical 
placebo-treated controls studied under identical procedures. Additional endpoints include change 
in NAFLD Fibrosis score and body composition by DXA.  
 
Aim 2: We will study the following with pre- and post-treatment liver biopsies: Aim 2A: A 
hypothesis-generating transcriptomic approach via bulk RNAseq will be used to identify target 
genes and cellular pathways of hepatic steatosis, inflammation and fibrosis that are engaged by 
GH augmentation. Aim 2B: Changes in intrahepatic immune cell profiles as demonstrated by 
single cell RNAseq (SeqWell), with attention to reduction in the dominance of intrahepatic CD4 T 
cells with a pathogenic Th17 profile. 
 
Participants from the Protocol 2014P001680 (“Growth Hormone and Intrahepatic Lipid Content in 
Patients with Nonalcoholic Fatty Liver Disease” PI: Miller) will be used to formulate a control group 
for analysis. 
 
 
4. 
Subject Selection 
 
III. SUBJECT SELECTION 
A. Inclusion/Exclusion Criteria 
• 
Aim 1: Subjects: N=15 (goal of 10 completers) with NAFLD/NASH.  
o Inclusion Criteria:  
• 
Age 21-60yo and generally healthy  
• 
BMI≥25 kg/m2 
• 
BMI≥23 kg/m2 for subjects whose background is South Asian, 
Chinese, Middle Eastern, Black African, or African-Caribbean. 
*2-month 
Lab Check 
*2-month liver panel will be performed in any subject 
whose 1-month liver function tests are above the 
normal range and elevated compared to baseline (pre-
drug). 
(n=50) 
 
3-month 
Visit 
1-month 
Visit 
4.5-month 
Lab Check 
Baseline Visit 
(n=15) 
1º Endpoint  
Assessment 

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• 
Radiographic or histologic diagnosis of NAFLD / NASH 
• 
IGF-1 level <3rd quartile of normal for age. 
 
o  Exclusion Criteria:  
1. Contraindications to MRI imaging (primary endpoint) 
2. Diabetes mellitus, defined as fasting glucose ≥ 126 mg/dL or 
hemoglobin A1C ≥6.5 or use of any medications prescribed to treat 
hyperglycemia is exclusionary for Aim 1.  
a. Subjects whose fasting glucose result at the screen visit is ≥ 126 
mg/dL and who do not have a prior history of diabetes mellitus will 
be offered an optional retest with inclusion if subsequent repeat 
fasting glucose is < 126 mg/dL. Subjects with repeat glucose  ≥ 126 
mg/dL will be excluded from the study. 
3. History of cancer/malignancy of any organ system other than previously 
fully resected basal cell carcinoma of the skin  
4. Significant renal disease.  
5. Unwilling or unable to perform age- and sex-appropriate cancer 
screening such as mammogram, PAP and/or colonoscopy 
6. Decompensated or unstable cardiovascular disease (for example, 
heart failure, unstable coronary disease, uncontrolled arrhythmias) at 
the discretion of the study physician 
7. Active carpal tunnel syndrome 
8. Significant alcohol use, defined as >2 drinks/day (14/week) in women 
or >3 drinks/day (or 21/week) in men 
9. Aspartate or aminotransferase levels >300 U/L, suggesting liver 
disease other than NAFLD/NASH. 
10. Other known liver disease, for example, autoimmune or viral hepatitis, 
hemochromatosis or alcoholic fatty liver disease. 
11. Evidence of hepatobiliary and hepatic impairment such as: 
a. INR >1.3 
b. TB >1.5 mg/dL (with  exception of Gilbert’s with elevation of 
indirect bilirubin in the presence of direct bilirubin of < 0.4 mg/dL) 
c. Albumin <3.5 g/dL 
d. Platelet count <150,000 /uL 
e. Historical or screening biopsy consistent with cirrhosis 
f. Imaging suggestive of cirrhosis (e.g., splenomegaly, varices, 
nodular appearance of liver, radiographic evidence of ascites) 
g. History of clinical events of liver decompensation such as variceal 
bleeding, presence of ascites, etc. 
12. Pregnancy or breastfeeding. 
13. Known pituitary or hypothalamic disease affecting the growth 
hormone axis 
14. Regular use of drugs causing hepatic steatosis in the past 12 months 
(chronic oral steroids, methotrexate, tamoxifen) 
15. Use of medications that may impact study endpoints, such as 
pioglitazone or Vitamin E. 
16. Treatment with medications without acceptable alternative that may 
interact with ibutamoren, including:  
a. Moderate or strong inhibitors of CYP3A/4. 

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b. Moderate or strong inducers of CYP3A4. 
c. Medications known to act as strong inhibitors of P-glycoprotein (P-
gp).  
17. Unsuitable for study per investigator discretion 
18. Known HIV Diagnosis 
• 
Aim 2: N=7 subjects (goal of 5 completers) participating in Aim 1 study without 
contraindication to liver biopsy such as:  
1. Subjects are already excluded from Aim 1 for INR >1.3, which is more 
stringent than typical biopsy exclusion criteria of INR >1.5  
2. Subjects are already excluded from Aim 1 for platelets <150,000/µL, 
which is more stringent than biopsy exclusion criteria of platelets < 
50,000/µL  
3. Requirement for chronic anticoagulation (other than aspirin) 
4. History of bleeding disorders 
 
B. Source of Subjects and Recruitment Methods 
Recruitment will be performed by study personnel, including research coordinators, nurse 
practitioners and physician staff. To maximize enrollment of subjects, subjects will be 
recruited from a large population of patients with NAFLD through the following locations and 
the following resources: 
1) Prior participants with overweight/obesity who have participated in Neuroendocrine Unit 
research studies: We will recruit from prior research studies from our unit by contacting 
research subjects who have indicated that they are interested in participating in future 
research studies. 
2) MGH Fatty Liver and GI Clinics: We will also recruit from the MGH Fatty Liver Clinic, an 
MGH referral center for NAFLD that sees approximately 500-700 patients per year, 50% 
with NASH, and performs approximately 2-3 biopsies per week.  
3) MGH NAFLD Cohort: The MGH NAFLD Cohort is a repository of patients enrolled from 
the MGH Fatty Liver Clinic and the MGH Weight Center since 2011. Over 1900 individuals 
have been enrolled to date, with collection of plasma, serum, DNA and liver tissue. Based 
on biopsy data, the cohort includes 19% with normal histology, 47% with simple steatosis 
and 34% with NASH. Sixty percent of the cohort has fibrosis, and 20% has advanced 
fibrosis. Based on these data, the cohort contains over 500 postmenopausal women with 
NAFLD who are potentially eligible for the proposed research. Additionally, the majority of 
these subjects have consented to be recontacted for future studies, so a significant 
proportion of NAFLD/NASH recruitment will come from this heavily pre-screened 
population.  
4) Mass General Brigham Hospital Research Patient Data Registry (RPDR): Additional 
recruitment will involve the Mass General Brigham Hospital Research Patient Data 
Registry (RPDR), which allows targeted searches of individuals within the Mass General 
Brigham system by age, sex, diagnosis with the ability to filter out patients by study-
specific exclusion criteria. This results in a highly targeted recruitment list that allows 
investigators to contact potential subjects at the approval of their treating doctor and/or 
through direct contact if patients have consented to this service. Using the targeted 
recruitment list from RPDR, in conjunction, we will also recruit subjects through Patient 
Gateway following the new OPT-OUT model. We will send USPS-mailed recruitment 
letters to potential subjects in the targeted recruitment list who do not have an “Active” 
Patient Portal Status. 

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5) Boston Area NAFLD Research Group network: Targeted recruitment of NAFLD subjects 
will also be facilitated through the Boston Area NAFLD Research Group network, which 
includes physician members from all Boston-area hospitals.  
6) “Research Studies Seeking Volunteers” email: We will include our protocol in the 
“Research Studies Seeking Volunteers” email that is sent weekly to all individuals holding 
email accounts at the MGH and BWH (>20,000 people). Our most recent advertisement 
on this email seeking obese adults generated more than 100 inquiries.  
7) Craig’s List and other various electronic platforms that allow research study 
advertisements have also been a rich source of study volunteers in our experience.  
8) Research Study Volunteer Program (RSVP): We will also contact potential participants 
through RSVP which is a Mass General Brigham Healthcare registry that maintains the 
names of individuals interested in being contacted about studies; currently in RSVP, there 
are >10,000 individuals registered as “healthy volunteers” interested in considering 
participation in studies.  
9) Advertising flyers will be hung on community bulletin boards and advertising postcards will 
be sent to thousands of local residents described by the target demographics inviting them 
to initiate contact if they are interested in learning more about our studies.  
10) To increase minority recruitment, we will also use the new Community Access, 
Recruitment, and Engagement (CARE) Unit which has been recently established at MGH 
in the Division of Clinical Research under the direction of Jonathan Jackson, MD. This unit 
provides consultation services at no charge and works with research groups such as ours 
to engage minority communities and increase minority recruitment.  
11)  Mass General Brigham Rally online platform. 
12) RENDER: We will recruit potential subjects through targeted RENDER searches. 
RENDER is a radiology scan search software that allows for a targeted search of past 
radiology scans. Eligible patients marked “okay to contact” on EPIC will be first 
introduced to the study via our IRB-approved recruitment letter sent via USPS/patient 
gateway. As outlined in this approved letter, we may call eligible patients directly after a 
two-week period if we do not hear from them. 
 
 
5. 
Subject Enrollment 
 
A. Enrollment 
Subjects responding to the initial recruitment advertisements will undergo initial prescreening by 
phone, and if potentially eligible for participation, will be invited to participate in screening visits 
to determine study eligibility.  For Specific Aim 1 (main study), we expect to screen 50 
radiographically-proven NAFLD subjects and enroll 12 NAFLD subjects, 6 women and 6 men, 
with NAFLD, in order to obtain 10 completers. We propose to replace dropouts to a goal of 10 
completers as time and funding allow. For Specific Aim 2 (biopsy substudy), we expect to 
screen 20 qualifying participants from Aim 1 of this protocol to obtain 7 enrolled participants with 
a goal of 5 completers with pre- and post-treatment biopsies. Subjects may be consented for 
Specific Aim 2 (biopsy substudy) at the time of screen for Specific Aim 1 (main study). Subjects 
will automatically be ineligible for Specific Aim 2 (biopsy substudy) if they do not qualify for 
Specific Aim 1 (main study). 
 
B. Consent 
All subjects will receive the written consent form or virtual eConsent form via MGB-approved 
eConsent platform (REDCap) for the study as well as the Human Subject’s Bill of Rights. These 
documents will be read by the study subjects and also reviewed by the study subject with a 

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clinician or licensed nurse practitioner prior to participating in the study. Any questions, 
concerns, or ambiguities will be clarified by a licensed physician investigator or licensed nurse 
practitioner prior to the patient signing consent.  Potential study subjects will sign informed 
consent and only then will begin participation in the study. If new information is ascertained 
during the study, we will modify our consent and re-consent our patients. There will be one 
consent form for Aim 1 and one consent form for the Aim 2 biopsy study. As noted in the remote 
procedure section of this protocol, the consent may be performed remotely via phone with the 
use of approved electronic signatures. Subjects will be reminded that deciding not to participate 
in the research study will not affect their care at MGB as described in the consent form. 
 
C. Study Drug Start 
Aim 1 participants who qualify and are enrolled in this study will start the medication after 
baseline testing is complete (as described below). This is an open-label pilot study.  
   
 
6. 
STUDY PROCEDURES  
 
Visit Components
Screen Baseline 1 month
2 month 
lab check 3 month 4.5 lab 
check
6 month 
COVID-19 Screening Phone Call
x
x
x
x
x
x
x
Liver Ultrasound
x
NAFLD Fibrosis Score
x
x
DXA
x
x
MRI/MRS
x
x
Waist-Hip Ratio
x
x
Endocrine/Misc. Labs
Blood: TSH
x
Blood: HCV Antibody
x
Blood: HBV Surface AG
x
Peripheral Blood Mononuclear 
Cells (PBMCs)
x
x
Ibutamoren Stimulation Test
x
Blood: Insulin, lipids
x
x
Safety Evaluation
Physical Exam***
x
x
x
x
x
Blood: INR
x
Blood: Creatinine
x
Bood: CBC
x
x
Blood: Liver function tests
x
x
x
x
x
x
x
Blood: Fasting Glucose
x
x
x
x
x
Blood: HbA1c
x
x
x
Blood: IGF-1
x
x
x
x
Urine pregnancy test
x
x
x
x
x
*** Optional, limited physical exam will be performed at the discretion of the study provider
Table 1. Aim 1 Schedule of Procedures
Open label ibutamoren mesylate (oral 25 mg daily) with be administered to 12 subjects (goal 10 
completers) with comparison to identically-studied, historical placebo-group controls.

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A. Study Visits for Specific Aim 1:  
1. Screening Visit : (n=50, approximately 50% women) 
 
After informed consent, subjects will be evaluated for eligibility with:  
• 
A basic metabolic panel, INR, CBC, TSH, fasting glucose, hemoglobin A1c 
(HbA1c), hepatic function panel, and IGF-1 will be performed. 
• 
Records of cancer screenings appropriate for the age and gender of the 
participant will also be requested. 
• 
Height and weight will be measured, and BMI will be calculated.   
• 
A history and physical will be performed.  
• 
A pregnancy test will be performed in all premenopausal women with 
childbearing potential. 
• 
A liver US or liver ultrasound elastography (Fibroscan) will be performed in study 
subjects who do not have a known diagnosis of NAFLD.  
o Due to limited ultrasound sensitivity for screening for fatty liver, subjects 
will be invited to a screening MRI for assessment of NAFLD if the subject 
otherwise qualifies for the study but has a negative screen ultrasound for 
NAFLD. 
• 
Individuals will be queried regarding alcohol use as well as for history of other 
chronic liver disease.  
• 
Hepatitis C antibody and Hepatitis B surface antigen tests will be performed in 
study subjects who have not had this as a part of their clinical care. 
• 
Serum and plasma samples will be drawn and stored frozen for future testing.  
 
Remote Blood Draws for Screening Visit at Quest Diagnostics: to allow maximum flexibility 
with our subject’s schedules, the blood tests listed above can be drawn at a Quest Diagnostics 
facility close to the subject’s home location. Screen aliquots will not be obtained during a remote 
blood draw. 
 
2. Baseline and 6-month visit: (n=15 at baseline, n=10 completers: approximately 50% 
women) 
The baseline visit will occur within 12 weeks after the screening visit.  The following 
assessments will be made during the baseline visit, which will occur within a 30-day 
period and can occur in one session or over multiple days depending on schedules and 
patient preference. The 6-month visit will be performed during a +/- 3 week interval 
around the indicated return time to allow for potential scheduling conflicts. The order of 
the tests may vary depending on the subject and TCRC availability. 
• 
Interview to determine whether any changes in medical history since the 
screening visit has occurred 
• 
BMI, waist-hip-ratio measured 
• 
In the fasting state, a blood sample will be obtained to determine glucose, insulin, 
GH, IGF-1 (6 mo only), CBC (6 mo only), HbA1c (6 mo only), lipids, triglycerides, 
and liver function tests. Note: Pre-treatment HbA1c, IGF-1, CBC will have 
already been performed at the screening visit and are not repeated at baseline. 
• 
Fasting glucose will be performed at baseline and 6-month visits. Aliquots for 
insulin measurements will be taken at these time points as well. 
• 
A fasting GH-stimulation test will be performed at the baseline visit only using 
ibutamoren 25 mg oral dose with GH levels measured at 0, 30, 60, and 90 and 

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120 minutes. All hormones will be measured using gold standard techniques 
(including IGF-1 by LC/MS). 
• 
Serum and plasma samples will be drawn and stored frozen for future testing. 
• 
Peripheral blood mononuclear cells (PBMCs) 
• 
MRI: 1H-MRS of the right hepatic lobe will be performed at the baseline and 6-
month visits to quantify hepatic lipid content and other fat depots. LiverMultiScan 
sequences will also be performed for noninvasive analysis of hepatic iron 
content, inflammation and fibrosis. Sequences will also be performed to assess 
pancreatic fat, inflammation and fibrosis as well as renal inflammation and 
fibrosis. The entire protocol will be scheduled for one 45 minute MRI slot. 
o A baseline MRI will be acquired if the screen MRI occurred more than 6 
weeks prior to baseline procedures. Otherwise, the MRI procedure at 
baseline is not required.  
• 
Dual-energy x-ray absorptiometry (DXA) scan will be performed at the baseline 
and 6-month visits to determine body composition. 
 
3. Drug Start: Ibutamoren will be started at a dose of 25 mg orally daily, starting after 
baseline procedures are complete. All subjects receive drug in this open label study. 
 
4. 1-month follow up visit: (n=15, approximately 50% women): These visits will be 
performed between 3-6 weeks to allow for potential scheduling conflicts.  
• 
Study subjects will be assessed for interim medical history and side effects to study 
drug. An optional physical exam will be performed as indicated per the discretion of 
the study clinician. 
• 
IGF-1 will be measured as a safety lab  
• 
Pregnancy tests will be checked for all premenopausal women (can be done 
remotely with communication of result or at Quest Labs) 
• 
Fasting glucose and liver function tests will be measured as safety labs 
• 
If the visit is on-campus (MGH), serum and plasma samples will be drawn and stored 
frozen for future testing. 
 
5. 2-month lab draw: If 1 month transaminases (ALT or AST) are above the normal range 
and elevated compared to the baseline values, a 2-month (+/- 2 week interval) liver 
function panel will be measured. This blood draw can be performed remotely at a Quest 
Diagnostics location or at MGH at the preference of the subject.  
 
6. 3-month follow-up visit: (n=15, approximately 50% women) 
These visits will be performed during a +/- 2 week interval around the indicated return time 
to allow for potential scheduling conflicts.  
• 
Study subjects will be assessed for interim medical history and side effects to study 
drug. An optional physical exam will be performed as indicated per the discretion of 
the study clinician. 
• 
IGF-1 will be measured as a safety lab at all follow-up visits 
• 
Pregnancy tests will be checked for all premenopausal women 
• 
Fasting glucose, HbA1c and liver function tests will be measured as safety labs 
• 
If the visit is on-campus (MGH), serum and plasma samples will be drawn and stored 
frozen for future testing.  
 
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study investigator; at least one of these visits will be performed in person. Remote visits 
will be performed with a phone or video visit interview with remote labs and weight at 
Quest Diagnostics. Remote pregnancy testing will be arranged with the subject as 
needed (either via study-provided home pregnancy test or testing at Quest Diagnostics).  
 
7. 4.5-month lab draw: 
• 
A 4.5-month (+/- 2 week interval) fasting glucose and liver function tests will be 
measured as safety labs. This blood draw can be performed remotely at a Quest 
Diagnostics location or at MGH at the preference of the subject. 
 
Dosing for Aim 1: Ibutamoren mesylate will be dosed at 25 mg daily. Dosing may be reduced 
to 18 mg daily for an IGF-1 level above the normal range or GH-related side effects, but this is 
not expected based on prior studies of ibutamoren. Ibutamoren can be taken with or without 
food. 
1 Month Post-Study Follow Up Call: 
A study provider will attempt to contact subjects four weeks after study completion to document 
subject status at that time, which will be approximately one month after study drug 
discontinuation. Any remaining study results will be reviewed with the subject at that time.   
 
REMOTE CONSENT AND VISIT PROCEDURES: 
Virtual Consent and Screen Medical History:  
In order to minimize potential COVID-19 exposures for study staff and subjects, consent and 
partial screening procedures may be performed virtually (via phone or MGB approved video 
platform) prior to an in-person portion of the visit. We will follow all MGB eConsent procedures. 
After consent via an MGB approved e-consent platform (via REDCap), the study provider will 
perform the screen medical history. The subject will also be instructed on how to fill out screen-
related forms electronically. The subject will be told immediately via phone if the provider 
determines by history alone that they would be ineligible for the study. If the subject otherwise 
appears to be eligible based on history, they will be invited for an in-person portion of the screen 
visit that includes the limited physical exam, vital signs, blood draw and ultrasound or liver 
ultrasound elastography (Fibroscan) as needed for diagnosis of NAFLD. Screening blood tests 
can be drawn at a Quest Diagnostics facility close to the subject’s home location to allow 
maximum flexibility with the subject’s schedule. 
 
Remote Follow-Up Visit Option 
Subjects may have the option to perform follow up visits (1 month and 3 month visits) remotely 
at the discretion of the study physician. If performed remotely, the visit will include remote labs 
(via Quest Diagnostics Locations) and medical history via phone call or virtual video visit with a 
study physician or nurse practitioner. For these remote visits, the study doctor or nurse will 
speak to the subject to obtain a medical history, and at those visits the optional physical exam 
would not be performed. The remote visit will be converted to an in-person visit if there is any 
concern based on updated history or symptoms at the discretion of the visit medical provider. 
For these remote visits, the study team will FedEx study medication to the subject in a manner 
approved by the research pharmacy as needed for resupply. The subject would bring back 
unused study medication to the study team at the next in person visit to maintain standard study 
drug accountability logs. Additionally, for off-site visits, a serum pregnancy test or off-site urine 
pregnancy tests (kit mailed to subject; subject sends photo documentation of result) will be 
performed in all women of childbearing age and status. Medical history and appropriate 
procedures for the baseline and 6-month visits can also be performed remotely in conjunction 
with the on-site procedures. 
 

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Remote Pregnancy Test Option for In-Person Visits 
Due to COVID-19, subjects may be allowed to perform a pregnancy test at home for any remote 
visit and on the day of any in-person visit in order to minimize potential exposures. The subject 
will electronically send the result to the study team for documentation. This will be under the 
discretion/direction of the study physician. 
 
B. SPECIFIC AIM 2: BIOPSY SUB-STUDY 
Study Visit for Biopsy Substudy 
Screening (n= 15): Subjects participating in the prospective Aim 1 study of this protocol 
will be invited to participate in a biopsy substudy for a total enrollment of up to n=5 pre- 
and post-treatment biopsy completers. Only participants in the main study (Aim 1) are 
eligible to participate in the biopsy sub-study (Aim 2). Subjects in Aim 2 will also undergo 
all procedures (including safety monitoring) that occur for participants in Aim 1. If they 
otherwise meet the inclusion/exclusion criteria for this sub-study based upon their 
previous study data, subjects will be invited to sign the biopsy sub-study consent form 
and present for two biopsy visits, one before starting study medication and one after 6 
months of study medication administration. 
Biopsy Substudy Subjects (n=7 enrolled for pre-treatment biopsy, goal n=5 
completers): 
The following procedures will be performed during each biopsy study visit (2 biopsy visits 
per subject): 
• 
Interview to determine whether any changes in medical history since the 
screening visit has occurred 
• 
Blood Draw: Subjects will have one non-fasting blood draw to measure safety 
labs (PT and CBC), peripheral blood mononuclear cells (PBMCs) and additional 
aliquots on the morning of each biopsy visit.  
• 
Liver biopsy 
 
The Aim 2 Liver Biopsy Substudy concludes after the post-treatment biopsy. 
 
Payment for Study Procedures 
Primary Study: $1,000 to complete the study with per-visit schedule below: 
• 
Baseline Visit $300  
• 
1-month and 3-month visits: $150 each 
• 
6-month visit: $400  
 
Biopsy Substudy: $1,000 to complete the biopsy substudy with per-visit schedule below: 
• 
Pre-treatment biopsy: $300 
• 
Post-treatment (6-mo) biopsy: $700  
 
 
We will provide parking at MGH garages free of charge and will additionally reimburse up to $20 
for travel to/from MGH for each visit. 
ADDITIONAL REIMBURSEMENT: Subjects will be reimbursed $25.00 for each additional blood 
draw related to glucose monitoring procedures or study discontinuation. 
Communication Via Text Messages (SMS) 
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messaging, study staff will send text reminders to notify and/or remind subjects of their 
upcoming visits. 
 
C. DEVICES AND PROCEDURES 
MR Spectroscopy:  We will perform proton MR spectroscopy (1H-MRS) of the right hepatic lobe 
to determine intrahepatic lipids (IHL) using a 3Tesla MRI device (Siemens Vida, Siemens 
Medical Systems, Erlangen, Germany) as we have previously described. [56] Advantages of 
higher magnetic field strength are an increase in signal-to-noise ratio resulting in improved 
spatial resolution and increased chemical shift dispersion, potentially improving assessment of 
other fat resonances. Subjects will be positioned head first in the magnet bore. A body matrix 
phased array coil will be positioned over the abdomen. A voxel measuring 20×20×20 mm (8 mL) 
will be placed within the right and then left lobe of the liver, avoiding vessels or artifact. Breath-
hold single-voxel 1H-MRS data will be acquired using PRESS pulse sequence without water 
suppression. Liver lipid estimates will be automatically scaled to unsuppressed water peak (4.7 
ppm) and expressed as lipid to water ratio. This ratio will be converted to percent fat using 
validated equations.[57] Measurement of IHL by 1H-MRS is recommended as a trial endpoint by 
the American Association for the Study of Liver Diseases (AASLD).[58] 
 
Fibroscan: Transient elastography (Fibroscan) is a rapid non-invasive technique that measures 
liver stiffness by the transmission of mild amplitude and low frequency (50Hz) through the 
intercostal space using a vibrator at the skin surface. The vibration induces a shear wave 
velocity through the hepatic tissue, which is directly related to tissue stiffness and is expressed 
in kilopascals (kPa). Transient Elastography is an inexpensive, reproducible, painless, rapid 
(<10 minutes), and easy-to-perform tool. It has been proven in many studies to correlate well 
with the degree or severity of fibrosis and or cirrhosis. It has sensitivity and specificity of greater 
than 95% for predicting cirrhosis with liver stiffness value of 14.1kPa. It is an ideal tool not only 
for assessing the degree of fibrosis/cirrhosis but can also be used to monitor disease 
progression and treatment efficacy. If the traditional liver ultrasound machine is unavailable, the 
Fibroscan will be performed at the screening visit to diagnose NAFLD using the controlled 
attenuation parameter (CAP). 
 
Liver Multiscan: Liver multiscan data will be acquired on the same scanner as the MR 
spectroscopy. Expiratory breath hold (<10 s) and EKG/pulse gating minimize motion from 
respiration or pulsation for the following sequences: T1 Mapping for Inflammation and Fibrosis 
and T2* Mapping for Hepatic Iron Quantification. Interpretation: The anonymized data sets will 
be transferred to Perspectum Diagnostics through a secure portal for image analysis and 
processing as is currently done for research scans in other groups at MGH. T1 mapping 
assesses liver fibrosis and inflammation. T1 relaxation time (ms) correlates with an increase in 
free water content contained in the imaged voxel as seen with hepatic inflammation and fibrosis. 
T2* (ms) estimates hepatic iron content. T1 mapping is corrected for hemosiderosis as measured 
from T2* mapping, yielding a corrected T1 (“cT1”) map.  
 
Pancreatic a) MOLLI and b) IDEAL: 
a) Pancreatic “Modified Look Locker Inversion Recovery” (MOLLI): using the same data 
acquired from the same scanner as the MR spectroscopy, a T1 map of the pancreas will be 
generated. This is a single-slice, multi-echo gradient acquisition performed at end-expiration 
breath-hold and lasts approximately 10 seconds. Interpretation: T1 measures pancreatic 
inflammation and fibrosis. 
b) Pancreatic “Iterative decomposition of water and fat with echo asymmetric and least-squares 
estimation" (IDEAL): using the same data acquired from the same scanner as the MR 

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spectroscopy, a proton density fat fraction (PDFF) map of the pancreas will be generated. 
This is a multi-slice, multi-echo gradient acquisition performed during end-expiration breath-
hold and lasts approximately 15 seconds. Interpretation: to estimate the presence and 
grading of pancreatic steatosis.  
 
Kidneys MOLLI: using the same data acquired from the same scanner as the MR spectroscopy, 
a T1 map of the pancreas will be generated. This is a single-slice coronal acquisition performed 
at the end-expiration breath hold and lasts approximately 14 seconds. Interpretation: T1 
measures kidney inflammation and fibrosis. 
 
Dual-energy X-ray-absorptiometry (DXA): Each subject will undergo a DXA scan at baseline 
and 6 month. DXA will be completed using Hologic QDR-Horizon A, Holigic Inc. Marlborough, 
MA.  
 
Dynamic Endocrine testing: A fasting GH-stimulation test will be performed using ibutamoren 25 
mg oral dose with GH levels measured at 0, 30, 60 and 90 and 120 minutes. All hormones will 
be measured using gold standard techniques (including IGF-1 by LC/MS). Blood will be drawn 
for potential measurement of the ibutamoren metabolite LUM-201 and M8 at every GH stim 
timepoint as noted above as well as a trough value at the 6 month visit as close to 24 hours 
after the previous dose as possible.  
 
Other laboratory testing: 
Liver function tests:  A standard liver function test panel consisting of ALT, AST, GGT, alkaline 
phosphatase, total bilirubin, direct bilirubin, indirect bilirubin, ferritin and albumin will be 
measured using a standard clinical platform. Lipids and Lipoproteins: A fasting lipid profile, 
including total cholesterol, LDL, HDL and triglycerides, will be measured via clinical platforms. 
Serum myostatin: serum myostatin will be measured at Brigham Research Assay Core. 
 
Liver Fibrosis Assessment: 
The NAFLD fibrosis score: This score predicts the probability of fibrosis in patients with NAFLD 
using a score that uses the patient's age, body mass index, blood glucose levels, 
aminotransferase levels, platelet count, and albumin. A high NAFLD fibrosis score of >0.676 is 
associated with a probability of advanced fibrosis (F3-F4) of 82 percent (sensitivity 43 percent, 
specificity 96 percent), and a score of <-1.455 is associated with a negative predictive value of 
88 percent (sensitivity 77 percent, specificity 71 percent) based on prior studies. [59, 60]   
 
Liver Biopsy: Percutaneous liver biopsy will be performed under ultrasound guidance by 
experienced interventional radiologists.  Participants with any contraindication to liver biopsy, 
including platelets < 50,000, elevated PT or PTT, or chronic anticoagulation use will not undergo 
biopsy.  Individuals on aspirin for primary prevention of CVD may undergo biopsy following 
discontinuation of aspirin for ≥5 days.  Pathology: One biopsy fragment will be fixed in 10% 
formalin for histopathological analysis. Biopsy specimens will be read in a blinded fashion and 
will document NAFLD activity score (ranging from 0-8, including steatosis, hepatocyte 
ballooning and lobular inflammation scores) and fibrosis stage on a scale of 0-4 per modified 
Brunt Stage.58 Bulk RNAseq: Whole liver tissue RNAseq analysis from liver biopsy specimens 
will be performed in the laboratory of Dr. Wein, whose laboratory has experience in tissue 
transcriptomic profiling to identify novel pathways downstream of hormone action.59,60 When all 
10 biopsy samples have been collected, RNA will be isolated via TRIzol (ThermoFisher), further 
purified using RNeasy columns (Qiagen), and purity/integrity assessed by bioanalyzer.60 After 
rRNA depletion, sequencing libraries will be constructed (TruSeq, Illumina) followed by 

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sequencing (25M reads/sample, Beijing Genomics Institute). After adapter trimming, reads will 
be mapped to the human genome using Bowtie261 and normalized expression counts and 
differentially-expressed genes (DEGs) will be determined using DESeq2.62 Data from individual 
subjects will be compared pre-to post-treatment to identify genes that are differentially regulated 
by ibutamoren. Principal component analysis will be performed to reduce complexity of these 
initial multi-dimensional datasets. If needed, group outliers will be identified to determine 
potential sources of “noise” in these biologic datasets. The biologic function of lists of DEGs will 
be determined by gene ontology analysis63, gene set enrichment analysis64,65, and enrichr66. 
Pathway analysis (Ingenuity, Qiagen)67 will identify upstream signals responsible for changes in 
gene expression associated with ibutamoren treatment.  
Immunological Studies: We will analyze liver samples pre- and post-GH augmentation with 
oral ibutamoren focusing on changes in the transcriptional landscape of the global intrahepatic 
immune cell population as captured through the SeqWell single cell RNAseq approach. This 
analysis will capture all key intrahepatic immune cell populations. 5,000 to 10,000 intrahepatic 
cells from a core liver biopsy will be loaded on a SeqWell chip and analyzed by RNAseq as 
described.51,68 These data will allow us to define changes in the immune cell composition 
induced by GH augmentation, will allow a second layer of analysis, i.e. changes in 
transcriptional regulation within the distinct immune cell populations and will reveal differences 
not only in the quantity, but also in the quality of different immune cell populations. 
RNA sequencing data for this study will be submitted to the unrestricted (open) access 
database: Gene Expression Omnibus (GEO) (https://www.ncbi.nlm.nih.gov/geo). In order to 
share our findings with other researchers who can expand on our work, we may need to provide 
information about the subject. The only subject information provided to these databases will be 
ethnic group, sex, age by decade and certain relevant diagnoses. 
DNA sequence data will be only be submitted to a controlled access database. DNA-
sequencing data for this study may be submitted to the database of Genotypes and Phenotypes 
(dbGaP), which is also run by the NIH.  The only subject information provided to these 
databases will be ethnic group, sex, time of day of sample collection, age by decade and certain 
relevant diagnoses. 
 
7. 
Risks and Discomforts 
A. Risks to the Subjects 
Human Subjects Involvement and Characteristics: This study will enroll a total of 50 (50 for Aim 
1, and 10 Aim 1 participants for Aim 2) obese, otherwise healthy, individuals ages 21 to 60 
(approximately 50% women). Subjects must be healthy, with no history of cardiovascular 
disease, renal impairment, diabetes or malignancy. Rationale for exclusions is discussed in the 
study protocol; in brief, these exclusions are designed to 1) exclude men and women at greatest 
risk for significant adverse events and 2) avoid confounding effects of medical conditions and 
medications. We exclude children and young adults through age 20 because GH administration 
in children prior to growth plate fusion causes linear growth, and GH administration could cause 
an increase in height.  
 
Dose Rationale: The ibutamoren mesylate 25 mg oral daily dosing was selected due to 
evidence for both effective augmentation and safety in the adult target population. The proposed 
dose of 25 mg oral ibutamoren daily effectively augments IGF-1 levels by approximately 40-
84%, which is within the range of normal.53, 56 Fixed dose ibutamoren mesylate at 25 mg daily 
has been shown to augment IGF-1 levels by 40% in healthy obese men56, which is comparable 
to or slightly below the 50% increase in IGF-1 levels we achieved (targeting upper-normal IGF-1 
levels) with daily, subcutaneous GH administration at 6 weeks in a similar population.29  
Additionally, this is within the range of IGF-1 augmentation seen in patients with HIV-associated 

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NAFLD with the subcutaneously administered GHRH analogue tesamorelin, which augmented 
IGF-1 by approximately 59% with a net treatment effect of a 2.9% decrease in liver fat.57 There 
is additional direct evidence with ibutamoren that this GH augmentation leads to effective GH-
related augmentation of metabolism and body composition. This includes studies of the 25 mg 
dose of ibutamoren mesylate that have demonstrated an increase in fat free mass in healthy, 
older adults (ages 60-81 years) at 12 months46 and a transient increase in basal metabolic rate 
and an increase in fat free mass in healthy adults with obesity at 2 months.56 These 
investigations are promising regarding safe and effective GH-augmentation by 25 mg daily 
ibutamoren mesylate and impacts on fat-free mass, and we now propose to study the impact of 
this dose of ibutamoren on hepatic steatosis, inflammation and fibrosis, endpoints which were 
not assessed in prior trials of ibutamoren mesylate at this dose.   
 
Regarding safety, there is a large clinical safety database (approximately 1000 adults for up to 2 
years of treatment at the proposed dose of 25 mg daily. Importantly, no serious adverse events 
related to ibutamoren mesylate have been reported to date in the proposed population at this 
dose (adults, ages 18-60 years).53 A safety signal was seen in prior studies in elderly subjects 
with congestive heart failure, as they were susceptible to the edema induced by increased GH 
secretion. However, significant heart disease or heart failure are exclusion criteria in this 
protocol, and the proposed study focuses on a younger, healthier population.53  
 
We expect the risks of ibutamoren mesylate administration to be minimal because ibutamoren is 
expected to raise IGF-1 levels (an integrated measure of GH secretion) within the normal range 
appropriate for age and sex.46, 56 Additionally, ibutamoren’s action as a GH secretagogue 
prevents hyperstimulation of the hypothalamic-pituitary axis by maintaining rather than 
overriding physiological feedback control within the GH/IGF-1 axis. While we do not expect IGF-
1 levels to exceed the normal range with the proposed dose of ibutamoren, we have included a 
dose reduction to 18 mg (28% dose reduction from 25 mg) as needed. Of note, the proposed 25 
mg dose of ibutamoren mesylate is less than the dose currently being studied in children, which 
aligns with the finding that adults with GHD require lower doses of GH for adequate treatment 
as compared to children with GHD. 
 
Regarding administration with food, a study of healthy young volunteers (Merck Study 001, 
page 64 of Investigator Brochure) demonstrated that a high carbohydrate breakfast slightly 
delayed absorption of ibutamoren at 25 mg daily, however, the AUC was similar between the 
fasting and fed states. Therefore, we will allow flexible dosing of ibutamoren in this study with or 
without food. 
 
Risks of each aim are outlined below. 
 
Potential Risks of Aim 1: 
 
Overview of Ibutamoren’s Investigational New Drug (IND) Status and Ongoing Research 
Notably, the FDA has reviewed all safety data on ibutamoren mesylate and allowed it to 
proceed (“Study May Proceed” letter received April 2020) to a Phase 2 study in children with 
pediatric growth hormone deficiency. The protocol entails enrolling children in parallel cohorts 
that explore doses more than 4x higher than what is proposed to be used in this study. The 
duration of this study in 3-12 year-olds is 6 months of dosing with an option to enter a long-term 
safety extension upon completion. The FDA’s confidence in the safety of ibutamoren (LUM-
201) stems from a very large non-clinical safety package that provides a large safety 
window at doses proposed for the pediatric study (including full acute, chronic, juvenile, 

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developmental and reproductive, and carcinogenicity toxicology studies) and a large 
clinical safety database (approximately 1000 adults for up to 2 years of treatment at the 
proposed dose of 25 mg daily and approximately 150 children for up to one year at 0.8 
mg/kg/day). 
 
Human Subjects Involvement and Characteristics of the Current Proposal:  
Aim 1: This is an open-label study of ibutamoren in otherwise healthy adults with BMI ≥25 kg/m2 
(BMI≥23 kg/m2 for subjects whose background is South Asian, Chinese, Middle 
Eastern, Black African, or African-Caribbean) with NAFLD. We will enroll 15 individuals 
ages 21 to 60 (approximately 50% women) for a goal of at least 10 completers. The following 
exclusion criteria are designed to 1) exclude subjects at greatest risk for any adverse 
events and 2) preserve data integrity and avoid confounding effects of medical 
conditions, medications and/or active weight loss. We exclude children in this proposal as 
GH augmentation in children causes linear growth, and dedicated Phase 2b trials of ibutamoren 
for pediatric GH deficiency will be initiated shortly.  
 
Subjects must be age 21-60 years old and meet all inclusion/exclusion criteria as outlined above 
to ensure that subjects are generally healthy. Select notable exclusion criteria are reviewed 
below in relation to the current study: 
• 
Current or prior history of malignancy  
• 
AST or ALT elevations >300 U/L that is beyond what is expected in NASH 
• 
Cirrhosis (compensated or decompensated), given that this is a more ill population and 
less appropriate for the current study.   
• 
Known cardiovascular disease or heart failure. Just as with our prior trials of GH 
administration, this is an exclusion criterion for the proposed trial, as growth hormone 
(given directly or released through a secretagogue like ibutamoren) could cause edema 
and worsen congestive heart failure (CHF). 
• 
Diabetes: Subjects may have prediabetes, but the following are exclusionary: 
(1) A clinical history of diabetes mellitus 
(2) Current drug treatment for diabetes mellitus 
(3) Screen A1C ≥ 6.5% 
(4) Screen fasting glucose ≥126mg/dL on two separate, consecutive screening 
measurements 
• 
Although GH administration itself can cause insulin resistance and reversible glucose 
elevations in a minority of patients, ibutamoren’s action as a GH secretagogue prevents 
hyperstimulation of the hypothalamic-pituitary axis by maintaining rather than overriding 
physiological feedback control within the GH/IGF-1 axis, and clinically significant 
deteriorations in glucose homeostasis with augmentation of GH pulsatility by ibutamoren 
have not been reported (see section below on Monitoring Glucose Homeostasis).  
• 
Women who are pregnant, actively seeking pregnancy or breastfeeding. Pregnancy 
tests will be performed in women of childbearing potential at each visit and use of 
contraception will be reviewed for both men and women through one month after study 
end. 
• 
Subjects may be excluded for other active medical conditions at the discretion of the 
evaluating study physician to ensure a generally healthy study population. 
• 
In vitro metabolism studies revealed Ibutamoren is metabolized by CYP3A4 and is a 
substrate of the P-gp transporter. It is possible that CYP3A inhibition/induction or P-gp 
inhibition may have an effect on the pharmacokinetics of Ibutamoren when co-
administered with compounds known to be inducers/inhibitors of CYP3A or inhibitors of 
P-gp.  Prior to enrollment on study and during treatment period, circumstances may 
arise which require temporary or permanent discontinuation of medications.  Medications 
that may interact with ibutamoren, include: 
o Moderate or strong inhibitors of CYP3A/4. 

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o Moderate or strong inducers of CYP3A/4 
o Medications known to act as strong inhibitors of P-glycoprotein (P-gp) 
 
The following exclusion criteria are to additionally ensure an appropriate study population and 
data integrity: 
• 
Other known liver disease (beyond NAFLD/NASH) 
• 
Significant alcoholic use, due to the possibility of alcoholic fatty liver disease 
• 
Medications known to cause NAFLD, including chronic oral steroids, tamoxifen or 
methotrexate 
• 
Weight instability prior to study entry 
• 
Routine MRI exclusion criteria, as this would preclude measurement of primary 
endpoints 
• 
Presence of pituitary disorders affecting the GH axis, as these individuals may not 
respond to a GH secretagogue. 
 
 
Aim 2: This Aim of the proposed protocol will enroll 5 of the subjects studied in Aim 1 into a liver 
biopsy substudy. Subjects will undergo two liver biopsies, one pre- and one post-treatment with 
ibutamoren mesylate. Participants with any contraindication to liver biopsy, including platelets < 
50,000µL, INR >1.5, or chronic anticoagulation are excluded from the trial. Individuals on aspirin 
for primary prevention of cardiovascular disease may undergo biopsy following discontinuation 
of aspirin for ≥7 days.  
 
Potential Risks of Aim 1: 
 
Administration of Ibutamoren:  
 
Ibutamoren is a potent, oral GH-secretagogue that has been studied in more than 1,200 
individuals over as long as 2 years with an excellent safety profile.[45-53] Ibutamoren mesylate 
was initially developed because of its high affinity for its receptor (GHSR1a), selectivity across a 
broad range of other receptors, high oral bioavailability and pharmacokinetics suitable for once 
daily oral administration.[61] The drug was subjected to extensive testing, including acute, 
chronic, juvenile, developmental and reproductive toxicology and carcinogenicity studies, all of 
which provide significant margins for continued development. For example, in the juvenile 
toxicology study, there were greater than 100-fold AUC margins between the top dose 
tested in the toxicology study, which was deemed the no observed adverse effect level 
(NOAEL), as no toxicity was observed.  
Oral ibutamoren has been studied in pediatric GH deficiency,[45] healthy aging populations (60-
81 years old),[46] hip fracture recovery,[47, 48] osteoporosis,[49] Alzheimer’s disease,[50] adult 
hemodialysis patients,[51] and obesity.[52, 53] In all of these populations, ibutamoren mesylate 
showed sustained increases in circulating GH and IGF-1. Specifically, 25 mg oral ibutamoren 
daily effectively augments IGF-1 levels by approximately 40-84%,  within the range of 
normal.[52, 53] This is the proposed dose in the current study and the dose used in the longest 
study of ibutamoren administration (2 years).[46] Importantly, no serious adverse events 
related to ibutamoren mesylate have been reported to date in the proposed population 
(adults, ages 21-60 years).[53]   
GH secretagogues such as ibutamoren preserve physiologic GH/IGF-1 axis feedback 
mechanisms. As an oral growth hormone secretagogue–receptor agonist, ibutamoren mesylate 
acts on GHSR1a receptors on the anterior pituitary and hypothalamus and restores the 
amplitude of the physiologic pulsatility of endogenous GH that is specifically lost in obesity. This 
mechanism of GH augmentation by ibutamoren has inherent feedback mechanisms, 
preventing hyperstimulation of the GH/IGF-1 axis and associated safety concerns. This is 

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in contrast to daily, subcutaneous GH administration, where a single daily, supraphysiologic 
pulse of GH is administered with dosing titrated to IGF-1 levels. Fixed dose ibutamoren 
mesylate (25 mg orally daily) has been shown to augment IGF-1 levels by 40% in healthy obese 
men,[52] which is comparable to or slightly below the 50% increase in IGF-1 levels we achieved 
(targeting upper-normal IGF-1 levels) with daily, subcutaneous GH administration at 6 weeks in 
a similar population.[29] Because IGF-1 levels (an integrated measure of GH secretion) will be 
raised to within the normal range appropriate for age and sex,[46, 52] we expect the risks of 
ibutamoren mesylate administration to be minimal.  
 
Additionally, IGF-1 levels will be monitored pre-treatment and at 1 month, 3 
months and 6 months on treatment. Significant elevations of IGF-1 above the normal range 
for age (Z score >2.5) will prompt either a 30% dose reduction (18 mg daily) or discontinuation 
from the study. This is not expected based on prior data or drug mechanism, given that 
ibutamoren’s action as a GH secretagogue preserves physiologic GH/IGF-1 axis feedback 
mechanisms. Moreover, hypopituitarism is associated with an increased mortality risk, which 
has been attributed to GH deficiency as one of the causes.[62] GH augmentation (by direct, 
subcutaneous GH injection) improves cardiovascular risk markers in such patients; moreover 
studies show that GH replacement may reduce the increased mortality conferred by 
hypopituitarism.[62-64]  
Routine cancer screening will be required prior to study entry to ensure a healthy, low-risk study 
population. Because GH is a growth promoting agent, there is the theoretical risk that GH or a 
GH secretagogue could promote tumor growth. In the 5 longer-term (up to 2-year) elderly 
studies, the combined incidence rate for malignancies in any ibutamoren treatment group was 
similar to the incidence rate of the placebo groups.[53]  Moreover, subcutaneous GH is not 
associated with an increase in malignancy even is administered for years.[62-64] To protect 
against risk in this protocol, all subjects will be required to be up-to-date with age- and sex-
specific cancer screening guidelines before inclusion into the study, similar to protocols 
involving GH administration. 
 
Subjects with known congestive heart failure (CHF) will be excluded to minimize risk. The only 
group of study subjects in whom possibly related serious adverse events occurred with 
ibutamoren administration was for that of elderly subjects after hip fracture, where a higher 
incidence of congestive heart failure (CHF) was found in the ibutamoren (n=4) versus placebo 
(n=2) groups (n=123 randomized).[47] However, heart failure only occurred in subjects over 80 
years old, and 3 of 4 of ibutamoren-treated subjects who developed CHF had a pre-existing 
diagnosis of heart failure. Heart failure has not been reported in any patient less than 80 years 
of age on ibutamoren. Mild fluid retention is a known potential side effect of GH itself, offering a 
potential mechanism for these events in a predisposed, elderly population, most of whom had 
preexisting heart failure. Additionally, in an earlier study in musculoskeletally impaired elderly 
patients, echocardiograms were performed in a subset of subjects at baseline and after 6 
months of ibutamoren therapy. There were no clinically significant differences between 
treatment groups in echocardiographic parameters (including ejection fraction, cardiac output, 
left ventricular wall thickness, and left ventricular mass) after 6 months of treatment.[53] 
Furthermore, after careful review of these data and all additional safety data, the FDA 
approved proceeding to Phase 3 studies for the indication of recovery from hip fracture. 
To protect against this risk, we propose to study healthy adults with NASH limited to the ages of 
21-60 years old with exclusions for a diagnosis of heart failure or cardiovascular disease. 
Additionally, as with all GH-related studies, edema is a closely monitored side effect that is 
elicited by history and exam at all visits in all subjects. 
 
Ibutamoren has been shown to increase fat-free mass. Ibutamoren is a long-acting ghrelin 
receptor (GHSR1a) agonist, however, it is critically important to recognize that its effects in vivo 
are markedly different from ghrelin, largely due to the differences in pharmacokinetic properties. 

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Ghrelin is highly unstable with a half-life in humans of about 5–10 minutes, whereas the half-life 
of ibutamoren is 8 hours.[48]  In contrast to short-acting ghrelin that has been associated with 
increased adiposity in mouse models, long-acting ibutamoren is not associated with an increase 
in abdominal fat. Changes in body composition and energy expenditure were anabolic in obese 
subjects, with an increase in fat-free mass and no change in visceral or subcutaneous adipose 
tissue depots over the 8 weeks.[52] Similarly, in 2-year, double-blind, randomized, placebo-
controlled clinical trial of healthy older adults (ages 60-81 years), ibutamoren produced a 
sustained enhancement of GH pulsatility and IGF-1 and resulted in an increase of fat-free mass 
with no significant differences in abdominal visceral fat or total fat mass.[46] Daily, 
subcutaneous GH administration is generally weight-neutral, with the following body 
composition changes consistently observed: decrease in fat mass (including liver fat and 
abdominal fat, including visceral fat), increase in fat-free mass (including skeletal muscle) and 
an increase in total body water.  In addition to measuring effects of ibutamoren on liver fat, we 
will measure effects on other fat depots, skeletal muscle, fat-free mass and total body water. 
Overall, we anticipate that ibutamoren may have beneficial effects on body composition 
(included as secondary endpoints) in the proposed population, and weight will be monitored at 
every study visit. 
 
Drug-drug interactions will be closely monitored. Ibutamoren and its metabolite M8 were 
assessed as substrates, inhibitors and/or inducers of the major cytochrome P450 (CYP) 
isoforms and transporters. Ibutamoren is primarily metabolized by CYP3A/4 and has been 
shown in vitro to induce CYP3A4, CYP2C8, CYP2C9 and CYP2C19, however at test 
concentrations that may not be clinically relevant at the current recommended dose. In vitro 
experiments also indicate Ibutamoren is substrate of P-glycoprotein (P-gp) and inhibits P-gp and 
Multidrug and toxin extrusion protein 1 (MATE1). At the proposed dose of 25 mg Ibutamoren, 
inhibition of P-gp and the MATE1 transporters are not projected to be clinically relevant. To 
protect against risk in the proposed study, we will exclude anyone on medications that are 1) 
moderate and strong inhibitors of CYP3A4; 2) moderate and strong inducers of CYP3A4; and 3) 
strong inhibitors of P-gp. 
 
Please refer to Appendix B: Ibutamoren Drug-Drug Interaction Reference List for a listing of 
proposed moderate or strong inhibitors, moderate or inducers of cytochrome P450 3A (CYP3A) 
and inhibitors of the P-gp transporter to be utilized for determining pertinent drug-drug 
interactions during the study. 
 
Summary of Drug Interaction Procedures: Subjects will be informed during the consent 
process that there is a potential for drug interactions with ibutamoren. They will be instructed to 
contact study staff before starting any prescription and/or over-the-counter medications or 
supplements. They will also be instructed to tell their doctor and any physician caring for them in 
the event of hospitalization that they are taking a study medication with a potential for drug 
interactions. Concomitant medications will be reviewed at every study visit with the subject. Any 
newly started medications will be brought to the attention of the PI for review. Concomitant 
medications will also be reviewed regularly with the PI at scheduled safety meetings. Study 
participants will be given a letter they should share with their primary physician to inform them of 
study participation and concomitant medication restrictions. Subjects will also be informed to 
contact the study staff between study visits to discuss any new potential medications. The study 
team has compiled a list of drugs that qualify under the above interactions and will continue to 
review all medications as the study proceeds. 
 

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Radiation exposure: A portion of this research study involves exposure to radiation from up to 
two DXA scans. Scans will be performed at the baseline visit and six month visit in Aim 1.  
• 
Subjects completing Aim 1 of the study will be exposed to a total of 0.016 mSv 
from a total of two DXA scans for body composition (0.008 mSv per scan, one at 
baseline and one at 6 months). 
MRI/ MR spectroscopy: MRI and MR spectroscopy will be performed using FDA approved 
devices and pulse sequences. There are no known foreseeable risks associated with exposure 
to MRI, provided there are no metallic implants (i.e., vascular clamps or pacemakers).  All 
potential subjects will be screened for the presence of such prior to the exam. A standard MRI 
questionnaire will be administered to all potential study subjects, and no study subject with a 
contraindication to MR testing will be admitted to the study.  Some subjects report some 
claustrophobia during MRI scans.  If a patient expresses any discomfort during the scan, the 
procedure will be aborted and not repeated without his/her full consent. 
 
General Considerations: IV placement and blood sampling is performed in the study, and there 
is a minor risk of infection, bruising, or syncope during a blood draw. There is also potential 
discomfort of having an IV placed and having blood drawn. Lightheadedness is a possible side 
effect from overnight fasting. The blood draws will be performed by trained staff who have 
certificates documenting their ability to draw blood. 
 
Liver biopsy: Ultrasound-guided percutaneous liver biopsy will be performed by trained 
interventional radiology staff who specialize in gastrointestinal procedures at the MGH.  
Subjects will be observed as outpatients following liver biopsy per standard interventional 
radiology procedure.  The risks associated with liver biopsy include pain, transient hypotension 
(vasovagal response), bleeding, and transient bacteremia.  Participants with any 
contraindication to liver biopsy, including platelets < 50,000, elevated PT or PTT, or chronic 
anticoagulation use will not undergo biopsy.  Individuals on aspirin for primary prevention of MI 
may undergo biopsy following discontinuation of aspirin for ≥7 days.  After discharge from 
interventional radiology following the procedure and outpatient observation, subjects will also be 
called the next day by study staff to ensure that any post-procedure pain has resolved and that 
no new symptoms are present.  Subjects with persistent pain or other concerning symptoms will 
be asked to return for evaluation.  Dr. Corey, a central member of our study staff, has 
successfully conducted previous studies with liver biopsies performed as described above. 
We will in no way discourage use of any medications that are clinically indicated for the subject. 
Subjects will be discontinued from the study if they start a medication that is known to affect 
liver fat, including methotrexate, estrogens, chronic oral steroids or SERMs (such as tamoxifen). 
The subject will be able to continue in the study if medications that are not known to affect liver 
fat, such as a statins, are started. 
B. Protection Against Risk  
In addition to the formal safety monitoring plan described, below, the procedures to protect 
against or minimize potential risks include the following: (1) the assignment of unique study 
subject numbers to patients, (2) the use of these primary identifiers throughout the study, (3) 
storage of information in locked file cabinets, and (4) access limited to study personnel for these 
file cabinets and data.  The blood draws will be performed by trained staff who are certified to 
draw blood.  We are performing a physical examination and routine laboratory tests prior to 
allowing anyone to enter the protocol to ensure that subjects are medically stable.  Close 
monitoring of patients throughout the study will ensure that adverse effects from our 

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interventions.  All study subjects will be instructed on how to contact study clinicians in the case 
of an emergency.   
 
 
8. 
Benefits 
 
There is no expected benefit to participation in this study.  If a subject receives ibutamoren 
in this protocol, it is possible that their amount of liver fat may decrease during the study.  
However, those effects are not promised or guaranteed.  If benefits occur, there is no way to 
know how long they will last.  If a medical condition is discovered, one will be referred to 
your physician.  It is possible that information learned from this study may help improve 
therapy for people who are obese. Liver biopsy histologic analysis is the gold-standard for 
assessment of inflammation and fibrosis in NAFLD/NASH, and this clinical information will 
be provided to subjects and their medical team for those who participate in the liver biopsy 
substudy.  
 
 
9. 
Statistical Analysis 
A. Statistical power and Analysis 
Aim 1A Statistical Power: The primary endpoint of Aim 1A is change in liver fat by 1H-MRS. 
With N=20 completers (10 open-label ibutamoren and 10 historical placebo-group controls 
studied with identical procedures from Protocol 2014P001680 “Growth Hormone and Intrahepatic 
Lipid Content in Patients with Nonalcoholic Fatty Liver Disease”), we will have 80% power to 
detect a 2% absolute difference in change in liver fat between GH and placebo utilizing an 
estimated SD of the change in liver fat of 1.6% based on a study of a diet-based intervention for 
NAFLD.[65] Notably, this calculation already allows for a generous dropout rate of 17% (2 
dropouts from 12 enrolled). Additionally, Stanley et al.[66] reported a 2.9% change between a 
subcutaneous GH secretagogue and placebo, which is likely an underestimation of our expected 
effect given that study involved subjects unselected for NAFLD.  
 
Aim 1B Statistical Power: The primary endpoint is the cT1 Score by LiverMultiScan. We will 
have 80% power for a cohort of N=20 subjects  with a two-tailed significance level of 0.05 to detect 
a difference of 76 ms in cT1 between the ibutamoren and placebo groups assuming a SD of 57.4 
ms  as reported in a NAFLD treatment-study by Harrison et al.[67] Allowing for dropouts (n=18), 
the detectable difference in cT1 is 80 ms. Both of these estimates are less than the actual change 
in cT1 score of 81.6 ms seen over 3 months of drug treatment in the same study.  
 
Aim 1A and 1B Data Analysis Plan:  A pooled random slopes model analysis of treatment  
effect across sexes with weights equaling the frequency of sexes in the sample. A secondary 
analysis will test for the treatment-sex interaction. For all analyses, an intent-to-treat analysis will 
be performed. We will apply guidelines developed by the National Research Council regarding 
missing data.66 Our primary analysis assumes that data is missing at random. We will conduct 
two sensitivity analyses: (1) assumes that the missing data is a function of the unobserved random 
effect82 and (2) tests the model’s assumptions under other missingness mechanisms.83  
 
Aim 2A Data Analysis Plan: We predict that GH augmentation by ibutamoren will lead to 
changes in hepatocyte function (increased lipolysis and fatty acid oxidation and reduced 
glycolysis and de novo lipogenesis). Chronic ibutamoren treatment may also lead to changes in 
differentiation of non-hepatocytes (fewer activated myofibroblasts and reduced inflammatory 
signatures). Analysis of the RNAseq data will pay careful attention to whether DEGs identified are 
likely to be expressed in hepatocytes or non-hepatocyte liver cell types. Our bioinformatic 
analyses will exploit recent single cell RNA sequencing data available from healthy human and 
mouse livers[68, 69] to determine the most likely cell type of origin for the DEGs that are identified. 
This bulk transcriptomic analysis will define the molecular changes that occur in response to 

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ibutamoren administration in NAFLD. Molecular changes observed will be correlated with 
histopathologic outcomes along with radiographic and biochemical endpoints included in the 
parent trial. This hypothesis-generating transcriptomic approach will define new target genes and 
cellular pathways engaged by GH in NAFLD. The primary analysis will be within subjects. A 
secondary analysis compared with historical, placebo-treated subjects will also be performed.  
 
Aim 2B Data Analysis Plan: Longitudinal studies in humans with two-paired samples around a 
clinical perturbation are much more powerful for generating robust and reproducible data using 
new generation sequencing technologies than cross-sectional comparisons, as they control for 
the heterogeneity of patient populations. We have recently studied human virus-specific CD8 T 
cells before and after HCV therapy. Paired samples from just 6 patients led to highly significant 
differential expression signals for hundreds of genes with very little noise and with high 
concordance to a similar study by colleagues (Lauer Group, manuscript in submission). The Lauer 
and Shalek labs have considerable experience with transcriptomics data analysis[70-73] and 
have established data quality control and analytical pipelines for single-cell RNAseq. We prepare 
mRNA or total RNA libraries (SMART-Seq v4 Ultra Low Input RNA Kit), assess quality (Agilent 
Tapestation) and sequence on an Illumina Novaseq 6000. Data are processed and quality 
controlled (standardized STAR-PORT pipeline: https://github.com/itmat/Normalization). R 
packages (limma-voom, GSVA, WGCNA) are used for downstream analysis. Data analysis is 
based on ongoing studies, allowing us to define immune cells based on key gene expression 
patterns. We will track the relative frequency of these immune cell subtypes over time by treatment 
group using false discovery rate methods.[74]  
 
 
10.   Monitoring and Quality Assurance 
A number of procedures will be instituted to protect against potential risk involved in this 
prospective protocol, as follows: 
 
Monitoring for Side Effects: The side effects of ibutamoren are similar to those expected with 
GH administration.[46, 52] We will monitor for all potential known GH-related side effects, which 
based on prior studies are generally minor and reversable. These include mild swelling, mild 
joint discomfort, muscle aches, median and ulnar nerve paresthesias or headaches. Ibutamoren 
has generally been well tolerated in pediatric patients and adults in the age groups proposed in 
this study (ages 21-60 years). Additionally, our prior NIH-funded study titled “Growth Hormone, 
Cardiovascular Risk and Visceral Adiposity” (NCT00131378), we administered low-dose, 
subcutaneous daily GH to obese men and women of the same age range as proposed in this 
protocol with a similar expected increase in IGF-1 levels. There was no significant difference in 
side effects between the GH group and placebo in this study with the exception of a higher 
incidence of reversable median/ulnar neuropathy in men versus placebo.[29, 30] Moreover, in 
patients with hypopituitarism, it has been clearly shown that physiologic dosing of GH, i.e. 
dosing which results in IGF-1 levels in the normal range, do not result in development of 
complications suggestive of acromegaly, even when administered for years. Therefore, we 
should expect minimal if any side effects related to GH augmentation itself. Importantly, 
only one participant in Dr. Dichtel’s K23 study (2014P001680) of subcutaneous GH 
administration in subjects with NAFLD/NASH has discontinued the protocol due to one of these 
possibly related side effects. This patient was discontinued by investigators at three months 
after worsening of pre-existing joint pain and was later known to be in the placebo group (after 
unblinding).  
 
To protect against risk in the proposed study, patients will be carefully monitored for any GH-
related side effects, with assessment at every study visit, including a 2-week on drug phone call 
and the 1-month, 3-month and 6-month study visits. Additionally, study subjects will have 
access to an on-call study physician or nurse practitioner at all times (24 hours/day, 7 

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days/week), and are encouraged to contact the study team at any time with any changes in their 
baseline health status or symptoms. If any study subjects experience significant side effects that 
do not resolve on oral ibutamoren mesylate, we will perform a dose reduction by 30% to 18 mg 
or discontinue the subject from the study, depending on the clinical scenario.  
 
Monitoring Glucose Homeostasis: Although GH administration itself can cause insulin 
resistance and reversible diabetes mellitus in a minority of patients, clinically significant 
deteriorations in glucose homeostasis with augmentation of GH pulsatility by ibutamoren 
has not been reported. There are two opposing effects of GH on insulin resistance – direct 
negative effects and indirect positive effects mediated through changes in body composition. 
Moreover, while GH itself may have a subtle, direct effects on increasing insulin resistance, 
restoration of IGF-1 provides a counterregulatory effect of improving insulin sensitivity. In some 
studies of ibutamoren, very mild elevations in mean glucose levels within the normal range were 
observed that were statistically but not clinically significant. In one study of older adults, one 
subject in the ibutamoren group and one subject in the placebo group developed diabetes. 
Additionally, no subject was discontinued due to elevations in glucose the from the 2-month 
study of 25 mg oral daily ibutamoren mesylate in abdominally obese males (ages 18-50 years) 
that best approximates the proposed population.[52] Studies of tesamorelin, a subcutaneously 
administered GH secretagogue similar to ibutamoren, also showed no difference in glycemia or 
insulin resistance compared to placebo over 6-12 months, including in a study of 60 abdominally 
obese subjects similar to the proposed population.[66, 75] Additionally, in Dr. Dichtel’s 
completed K23 study (2014P001680) of subcutaneous GH administration in otherwise 
healthy, overweight/obese men and women with NAFLD, no subject out of nearly 50 
randomized was discontinued from the study due to elevations in fasting glucose or 
hemoglobin A1c into the diabetic range (prespecified criteria).  
  
To protect against risk in the proposed study, frequent assessments of glucose intolerance will 
be made according to the Data Safety and Monitoring plan. Briefly, subjects with a clinical 
history of diabetes mellitus or individuals on medications to treat diabetes will be excluded from 
the study. Fasting glucose and HbA1c ≥ 6.5% is consistent with a clinical diagnosis of diabetes 
mellitus and is exclusionary. If a screen fasting glucose is ≥ 126 mg/dL, the subject will be 
offered one repeat fasting glucose measure with inclusion if the repeat measure is < 125 mg/dL. 
Subjects with fasting glucose ≥ 126 mg/dL on two consecutive measures will be excluded from 
the study, as this would be consistent with a clinical diagnosis of diabetes mellitus. 
 
Fasting glucose will be then measured at 1,3 and 6 months and HbA1c measured at 3 and 6 
months on treatment. Any subject with a glucose safety measure in the diabetic range (fasting 
glucose ≥126 mg/dL on two consecutive measurements or a single HbA1c ≥6.5%) will be 
withdrawn from the study. If a single fasting glucose meets exclusion criteria at any visit (≥125 
mg/dL), an immediate repeat glucose will be performed allowing continuation in the study if the 
repeat measure is <125 mg/dL), which prevents unnecessary discontinuations for spuriously 
elevated single fasting glucose results. For fasting glucose elevations at the 1-month and 3-
month visits: 
• 
If fasting glucose 126-140 mg/dL:  
o 
Subjects will be counseled using the Lifestyle/dietary document (see 
Attachments section, already IRB-approved) 
o 
Subject will continue 25 mg daily ibutamoren and fasting glucose will be 
repeated.  
o 
If repeat fasting glucose is <126 mg/dL, continue the 25mg dose. If repeat 
glucose is again >125 mg/dL, decrease ibutamoren to 18mg dose and recheck 
fasting glucose within 2-4 weeks.  

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o 
If glucose remains <126 mg/dL on 18 mg dose, the subject can remain in the 
study. If glucose is ≥126 mg/dL on 18 mg dose, the subject will be discontinued 
from the study. 
• 
If fasting glucose is 140-170 mg/dL: 
o Subjects will be counseled using the Lifestyle/dietary document 
o Ibutamoren dose will be reduced to 18 mg daily, and fasting glucose will be 
repeated in 2-4 weeks.  
o If glucose remains <126 mg/dL on 18 mg dose, the subject can remain in the 
study. If glucose is ≥126 mg/dL on 18 mg dose, the subject will be discontinued 
from the study. 
• 
If fasting glucose is >170 mg/dL: 
o Subject will undergo drug holiday with a recheck of the fasting glucose after 1-3 
weeks. If repeat glucose is < 126 mg/dL, restart the drug at a lower 18 mg dose 
and recheck glucose in 2-4 weeks.  
o Upon recheck, if glucose remains <126 mg/dL on 18 mg dose, the subject can 
remain in the study. If glucose is ≥126 mg/dL on 18 mg dose, the subject will be 
discontinued from the study. 
If any subject is discontinued from the study due to worsening glucose homeostasis, he/she will 
also have follow-up labs measured off of treatment. Based on prior studies, we would expect 
blood glucose to return to the subject’s pre-treatment level after drug discontinuation.[29, 30] 
 
 
The chair of the proposed Data Safety Monitoring Board (and chair of Dr. Dichtel’s current K23 
award DSMB) is Dr. Jose Florez, who was selected due to his expertise as a diabetologist and 
familiarity with our group’s GH studies. After Dr. Jose Florez’s 2023 role transition to Chair of 
Medicine, as of DSMB 10/2023 meeting, Dr. Jules Dienstag will take his place as the DSMB 
chair for this clinical trial. Dr. Dienstag’s expertise as a hepatologist in the Department of 
Gastroenterology at MGH, and his prior involvement in Dr. Dichtel’s K23 DSMB, will be 
instrumental to the continuation of the monitoring of the study.  
 
Monitoring Liver Function Testing: Patients with NAFLD/NASH often have mild, baseline 
elevations in liver transaminases (AST/ALT) as well as fluctuations in these tests over time. 
Liver function tests will be monitored at baseline, with subjects excluded for AST or ALT greater 
than 300 U/L to exclude subjects with liver disease other than NAFLD. We will also exclude 
patients with known liver disease other than NAFLD and history of compensated or 
decompensated cirrhosis. Mild, asymptomatic, self-limited and reversable elevations in LFTs 
have been observed in a small number of subjects on ibutamoren mesylate. However, these 
elevations all resolved either on drug or after drug discontinuation, and notably also occurred in 
equal frequency in the placebo group of multiple studies. There have been no liver-related 
SAEs reported in studies of ibutamoren mesylate.[53] We expect any potential elevation in 
transaminases to improve over time, either by regression to the mean with the inherent 
variability in this population or due to improvement in NAFLD/NASH with ibutamoren. Published 
studies in adults do not suggest a concern for elevations in transaminases with GH 
augmentation by other methods, including direct GH administration[29, 30] or GHRH-
mimetics.[66, 75] Importantly, no subjects were excluded due to significant elevations in 
transaminases from Dr. Dichtel’s NIH K23 study of daily GH administration in subjects with 
NAFLD and NASH (n=41 completers).  
 
Assessments of liver function tests will be made frequently throughout the study, including at 
screen, baseline, 1 month, 2 months, 3 months, 4.5 months and 6 months. This frequent 

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reassessment also provides two pre-treatment measurements (screen and baseline), allowing 
exclusion of any subject with significant rises in liver function tests prior to drug administration.   
 
Pregnancy and Breastfeeding: There was no fetal harm shown in preclinical toxicology 
studies of ibutamoren. However, there is no existing clinical experience in pregnant or nursing 
women. Therefore, precautions against administration to pregnant or breastfeeding women will 
be instituted. All premenopausal female patients will have pregnancy tests on admission to the 
study prior to receiving study medication or radiation. Premenopausal women will also have 
serial pregnancy tests – one at every study visit.  
 
Subject Requirements and Counseling for the Prevention of Pregnancy: Females 
participating in this study must be of non-childbearing potential or must be using highly effective 
contraception for the full duration of the study and for 1 month after the last drug intake: 
• 
Non-childbearing potential is defined by cessation of menses for at least 12 months 
due to ovarian failure or surgical sterilization such as bilateral oophorectomy, or 
hysterectomy 
• 
Highly effective contraception includes: 
• 
Combined (estrogen and progesterone containing) hormonal 
contraception associated with inhibition of ovulation, including 
oral, intravaginal or transdermal preparations 
• 
Progestogen-only hormonal contraception associated with 
inhibition of ovulation, including oral, injectable or implantable 
preparations 
• 
Intrauterine device (IUD) 
• 
Intrauterine hormone release system (IUS) 
• 
Bilateral tubal occlusion 
• 
Vasectomized partner 
• 
Sexual abstinence 
• 
If female subjects are unable to use the above combination methods, they may 
choose to use the physical barrier method (used consistently and correctly) such as 
a diaphragm/cervical cap or male condom. Pregnancy tests will be monitored for all 
women of childbearing age at every visit. Women of childbearing age will also be 
instructed to call the study team immediately if they have a missed period and/or 
believe that they might be pregnant.  
 
• 
Males enrolled in the trial who are sexually active will be instructed to use highly 
effective contraception for the full duration of the study and for 1 month after the last 
drug intake. 
A. Independent Monitoring of Source Data 
A number of procedures will be instituted to protect against potential risk involved in this 
protocol.  All women of reproductive age will have pregnancy tests on admission prior to 
receiving radiation or study medication.  Such subjects will also have serial pregnancy tests – 
one at every study visit – and study participation will be discontinued if a subject becomes 
pregnant.  
Side effects of ibutamoren include effects of GH augmentation such as mild swelling or 
arthralgias, which occur in a minority of patients and resolve after the first few days of therapy in 
the vast majority of patients.  In those study subjects in whom such side effects do not resolve, 

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we will reduce the dose.  Because of the potential importance of insulin resistance to 
cardiovascular risk, we will investigate with validated techniques the effects of GH on insulin 
resistance in our population.  Because glucose tolerance may deteriorate with GH 
augmentation, especially acutely, we will not allow patients with uncontrolled DM to participate 
and we will discontinue study participation if a subject meets strict discontinuation criteria as 
outlined in the “Monitoring Glucose Homeostasis” section on page 25.  
 
A physician will be available at all times during the study by pager to answer any questions a 
patient might have.  The physician will arrange to immediately see every patient with a concern.  
All efforts will be made to protect the confidentiality rights of the study subjects who will be 
referred to by code numbers only.  Confidentiality of the patients will always be of paramount 
importance to study investigators.  No data on patients will be shared with persons other than 
those directly involved in the study, except at the documented request of the patient.  Samples 
that are sent to laboratories outside of MGH will be labeled with a non-identifying numeric code.    
 
B. Safety Monitoring 
A Data Safety Monitoring Board (DSMB) will be established consisting of:  1) a biostatistician, 
Suzanne Dahlberg, PhD, FASCO, Assistant Director of Clinical Trial Biostatistics and Data 
Management within the Institutional Centers for Clinical and Translational Research, Boston 
Children’s Hospital, and 2) Dr. Aaron Leong, Assistant Professor of Medicine, Harvard Medical 
School and an MGH endocrinologist and 3) Dr. Jules Dienstag, hepatologist in the MGH 
Gastroenterology Division. The Data Safety Monitoring Board will meet every six months after 
study activation to oversee the interventional study (AIM 1) only.  The DSMB will review safety 
data, including adverse events, at each meeting and will be available in the interim to consider 
any urgent matters.  Any serious or unexpected adverse events, or any other unanticipated 
problems involving risks to subjects or others, will be formally reported to the Mass General 
Brigham Institutional Review Board (IRB). 
 
Data Safety Monitoring Board Meetings:   
DSMB meetings will take place every 6 months. In addition, the Chairman of the Board may call 
ad hoc meetings. The Board will be provided with reports of serious adverse events as they 
occur and the chair of the committee has the responsibility of calling an ad hoc meeting if the 
type or frequency of the serious adverse events is of concern. The Board may request 
additional information from the Investigator in the course of its review. The Investigator shall not 
be present for part of the Board’s meeting.  
 
Safety Monitoring:  
1. 
 Review of all adverse events (expected, unexpected and serious) 
-Severity, frequency and reporting protocol adherence 
2. 
Review safety assessments described below 
4. 
Recruitment, enrollment (adherence to eligibility criteria) 
5. 
Dropout rates 
6. 
Protocol changes 
 
 
The major outcome choice following the data review by the Board is: 1) continuing the trial 
unchanged, or 2) modify the protocol and/or consent form, or 3) terminate the trial. 
 
The chairperson will be responsible for overseeing the meetings, developing the agenda and 
summarizing the meeting.  The chairperson is the contact person for the DSMB. 

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The DSMB responsibilities will include: 
1. Review of the research protocol, informed consent documents and plans for safety 
and data monitoring of the study. This review is to determine the risks and benefits to 
research subjects, protection and safety of the subjects and to offer suggestions for 
improving the study design. 
2. Review interim data to detect adverse effects to determine if the trial should continue 
as originally designed, should be changed or should be stopped based on the data. 
3. Evaluate the progress of the trial including recruitment goals, accrual and retention of 
participants and other factors that may affect the study outcome. 
4. Protect confidentiality of the study participants, trial data and results of the monitoring. 
 
 
Safety assessments for subjects in Aim 1: 
1.   IGF-I levels:  
a. Measurements at screen, baseline, 1 month, 3 month and 6 month 
b. Dose decrease (to 18 mg daily) for IGF-I levels above the upper limit of normal 
2. Glucose: Fasting glucose at screen, 1, 3 and 6 month visits. 
3. HbA1c: screening, 3 and 6 months 
4. Pregnancy testing at all visits for premenopausal women 
5. Liver function tests at screen, baseline and at the 1-month, 2-month (if 1-month 
transaminases are above the normal range and elevated compared to baseline), 3-
month, 4.5-month, 6-month visits, with action taken per the section below titled Liver-
related Adverse Event Assessment and Drug Induced Liver Injury Monitoring. 
 
Safety assessments for subjects in Aim 2: 
1.  INR  
2.  Platelets 
 
The physician investigator will review all laboratory results and those that are clinically 
significant.  
 
Drug-drug Interaction Management Plan: 
 
A letter will be sent to the subject’s primary care physician to inform them of the subject’s study 
participation and the possibility of concomitant medication restrictions.  
 
Individual subjects on the active study drug who will have acute medical conditions that require 
the use of a new non-study drug will have to be assessed by a study provider to ensure that 
there is no drug interaction with ibutamoren. A study provider will contact the subject and 
investigate the non-study medication: 
• 
If the non-study medication is confirmed to NOT have any interaction with the study 
drug, the study provider will instruct the subject to continue taking the study medication. 
• 
If the non-study medication is confirmed to interact with the active study drug, the 
provider will instruct the subject to stop taking the study medication until otherwise 
instructed. 
• 
Drug-drug Interaction Procedures: 
o Moderate and Strong CYP3A4 Inhibitor: Concomitant use of Ibutamoren 
with a moderate or strong CYP3A4 inhibitor increases ibutamoren 

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systemic exposure. Therefore, Ibutamoren can be restarted after 4 half-
lives after discontinuation of the moderate or strong CYP3A4 inhibitor. 
o Moderate or Strong CYP3A4 Inducers: Concomitant use of Ibutamoren 
with moderate or strong CYP3A4 inducers decreases ibutamoren 
systemic exposure. Therefore, Ibutamoren can be restarted immediately 
after discontinuation of a moderate or strong CYP3A4 inducer.  
o P-gp Inhibitors: Concomitant use of Ibutamoren with strong P-gp 
inhibitors may limit absorption of Ibutamoren and decrease systemic 
levels of Ibutamoren. Therefore, Ibutamoren can be restarted immediately 
after discontinuation of a P-gp inhibitor. 
 
Subject discontinuation criteria: 
Subjects will be discontinued from Aim 1 of the study if they develop  
1. 
Glucose homeostasis criteria: Please refer to the “Monitoring Glucose 
Homeostasis” section on page 25. This protocol prevents unnecessary 
discontinuations for spuriously elevated single fasting glucose results. 
2. 
Positive pregnancy test 
3. 
Severe / intolerable side effects of ibutamoren 
4. 
Development of malignancy  
5. 
Initiation of the following medications: OCPs, pioglitazone, or strong CYP3A4 inhibitors 
6. 
Liver-related discontinuation criteria as outlined per the section below titled Liver-
related Adverse Event Assessment and Drug Induced Liver Injury Monitoring. 
Liver-related Adverse Event Assessment and Drug Induced Liver Injury (DILI) Monitoring: 
Liver-related adverse events (AEs) will be graded on the Common Terminology Criteria for 
Adverse Events (CTCAE), Version 5. Abbreviations that follow include alkaline phosphatase 
(ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin 
(TB). 
Drug stop, drug induced liver injury (DILI) monitoring and subject discontinuation rules: For 
individual subjects, drug will be stopped if the subject develops any of the following:  
(1) Study drug will be stopped with the potential for restart for the following criteria 
outlined below (CTCAE Grade 2 and additional DILI Monitoring Guideline Criteria) 
regardless of relationship to ibutamoren mesylate.  
• 
Liver-related CTCAE Grade 2 AE based on ALP, ALT, AST or TB 
o Alkaline phosphatase: Between 2.5 and 5x ULN if normal baseline 
or between 2.5 and 5x baseline if baseline was abnormal. 
o ALT or AST: Between 3 and 5x ULN if normal baseline or between 
3 and 5x baseline if baseline was abnormal. 
o TB: Between 1.5 and 3x ULN if normal baseline or between 1.5 
and 3x baseline if baseline was abnormal (i.e. in Gilbert’s).  
• 
Additional DILI Monitoring Guideline Criteria[76] 
o ALT ≥300 U/L, regardless of baseline 
o ALT ≥2x baseline if abnormal with liver-related symptoms, 
including severe fatigue, nausea, vomiting and/or RUQ pain 
Repeat liver function testing (including ALT, AST, ALP and TB) will be repeated in 2-5 
days and subject will be referred to patient’s clinician to evaluate for other etiologies of 
abnormal liver function tests per DILI Consensus Guideline recommendations. Study 

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drug can only be restarted if alternative etiology identified and liver enzymes return to 
baseline (e.g. after episode of viral illness). It is expected that resolution and drug 
restart will occur within 14 days of drug discontinuation.   
 
(2) Study drug will be stopped without the potential for restart for any liver-related 
CTCAE AE grade 3 or higher based on ALP, ALT, AST, TB or clinical symptoms 
criteria, regardless of relation to ibutamoren mesylate. These include:  
• 
Alkaline phosphatase, ALT or AST: Greater than 5x ULN if normal 
baseline or greater than 5x baseline if baseline was abnormal. 
• 
TB: Between 3 x ULN if normal baseline or greater than 3x baseline if 
baseline was abnormal.  
• 
Clinical evidence of hepatic failure, including asterixis, mild 
encephalopathy, drug-induced liver injury, limiting self-care ADL, 
evidence of portal vein flow abnormalities associated with varices and/or 
ascites.  
Subjects will be discontinued from the study at this time without possibility of drug 
restart. 
Study discontinuation rules: Study discontinuation will be considered if any of the following 
occur, including (1) three subjects develop the same Grade 3 CTCAE attributed to ibutamoren 
mesylate; (2) two subjects develop any Grade 4 CTCAE attributed to ibutamoren mesylate; or 
(3) any one patient develops a Grade 5 CTCAE.  
If any of these patient or study discontinuation criteria are met, the clinical data will be reviewed 
by the data safety monitoring board (DSMB) for safety. An agreement will be reached regarding 
any additional safety monitoring or protocol changes. Minutes recorded during any such DSMB 
meeting will be recorded and sent to the FDA for review. 
C. Adverse Events Reporting 
All adverse events will be reported to the IRB in a timely manner according to the guidelines 
provided by Partner’s Human Subjects Research Committee. 
All treatment emergent serious adverse events will be documented and reported immediately to 
the IRB at General Brigham, as well as to the DSMB.  An event that is serious must be recorded 
on the case record and requires expeditious handling to comply with regulatory requirements. In 
the event that a patient becomes ill or injured as a direct result of participation in the research 
study, necessary medical care will be made available.  All adverse effects will be reported as 
per Mass General Brigham requirements. Potentially serious adverse events (SAEs) will be 
followed to resolution or stabilization and reported as SAEs if they become serious. Necessary 
dates related to the subject’s SAE will be provided to Lumos Pharma to ensure proper report, 
record, and documentation of the subject’s SAE.   
A serious adverse event is one that meets any one of the following criteria: 
a) Fatal or life-threatening 
b) Requires inpatient hospitalization 
c) Results in persistent or significant disability or incapacity 
d) Congenital anomaly 
e) Important medical event that may jeopardize the patient or require intervention to prevent 
serious outcome 
f) Cancer 
g) Overdose 
h) Results in development of drug dependency or drug use 

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11.   Privacy and Confidentiality 
 
☒ Study procedures will be conducted in a private setting 
☐ Only data and/or specimens necessary for the conduct of the study will be collected: We 
collect additional blood samples as allowed under informed consent for future research. 
☒ Data collected (paper and/or electronic) will be maintained in a secure location with 
appropriate protections such as password protection, encryption, physical security 
measures (locked files/areas) 
☒ Specimens collected will be maintained in a secure location with appropriate protections 
(e.g. locked storage spaces, laboratory areas) 
☒ Data and specimens will only be shared with individuals who are members of the IRB-
approved research team or approved for sharing as described in this IRB protocol 
☒  Data and/or specimens requiring transportation from one location or electronic space to 
another will be transported only in a secure manner (e.g. encrypted files, password 
protection, using chain-of-custody procedures, etc.) 
☒   All electronic communication with participants will comply with Mass General Brigham 
secure communication policies 
☒ Identifiers will be coded or removed as soon as feasible and access to files linking 
identifiers with coded data or specimens will be limited to the minimal necessary 
members of the research team required to conduct the research 
☒ All staff are trained on and will follow the Mass General Brigham policies and procedures 
for maintaining appropriate confidentiality of research data and specimens 
☒ The PI will ensure that all staff implement and follow any Research Information Service 
Office (RISO) requirements for this research 
☒ Additional privacy and/or confidentiality protections: As mentioned throughout protocol 
and consent form. 
 
 
 
12.   References 
 
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27. 
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33. 
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alcoholic steatohepatitis. Journal of hepatology, 2009. 51(2): p. 371-9. 
34. 
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Metab, 2007. 18(4): p. 134-41. 
35. 
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role of growth hormone signaling in hepatic lipid metabolism. The Journal of biological 
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36. 
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45. 
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growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in 
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46. 
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outcomes in healthy older adults: a randomized trial. Ann Intern Med, 2008. 149(9): p. 
601-11. 
47. 
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recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb 
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48. 
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patients with hip fracture. J Am Geriatr Soc, 2004. 52(4): p. 516-23. 
49. 
Murphy, M.G., et al., Effect of alendronate and MK-677 (a growth hormone 
secretagogue), individually and in combination, on markers of bone turnover and bone 
mineral density in postmenopausal osteoporotic women. J Clin Endocrinol Metab, 2001. 
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50. 
Sevigny, J.J., et al., Growth hormone secretagogue MK-677: no clinical effect on AD 
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51. 
Campbell, G.A., et al., Oral ghrelin receptor agonist MK-0677 increases serum insulin-
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APPENDIX A 
 
Data Monitoring Committee / Data and Safety Monitoring Board 
Appendix 
 
 
 
• 
To be completed for studies monitored by Data Monitoring Committee (DMC) or Data and 
Safety Monitoring Board (DSMB) if a full DMC/DSMB charter is not available at the time of 
initial IRB review. 
• 
DMC/DSMB Charter and/or Roster can be submitted to the IRB later via Amendment, 
though these are not required.  
 
A Data Monitoring Committee (DMC) or Data and Safety Monitoring Board (DSMB) will be 
convened for safety monitoring of this research study.  The following characteristics describe 
the DMC/DSMB convened for this study (Check all that apply): 
 
☒ The DMC/DSMB is independent from the study team and study sponsor. 
 
☒ A process has been implemented to ensure absence of conflicts of interest by 
DMC/DSMB members. 
 
DSMB members will be formally queried regarding COI prior to initial meeting. Anyone 
with COI will be replaced. 
 
☒ The DMC/DSMB has the authority to intervene on study progress in the event of safety 
concerns, e.g., to suspend or terminate a study if new safety concerns have been 
identified or need to be investigated.   
 
☒ Describe number and types of (i.e., qualifications of) members: 
1) a biostatistician, Suzanne Dahlberg, PhD, FASCO, Assistant Director of Clinical Trial 
Biostatistics and Data Management within the Institutional Centers for Clinical and 
Translational Research 
2) Dr. Aaron Leong, Assistant Professor of Medicine, Harvard Medical School and an 
MGH endocrinologist 
3) Dr. Jules Dienstag, hepatologist in the MGH Gastroenterology Division. 
 
☒  Describe planned frequency of meetings: 
At least every 6 months after study initiation. 
 
☒ DMC/DSMB reports with no findings (i.e., “continue without modifications”) will be 
submitted to the IRB at the time of Continuing Review. 
 
☒ DMC/DSMB reports with findings/modifications required will be submitted promptly 
(within 5 business days/7 calendar days of becoming aware) to the IRB as an Other 
Event. 
   

Mass General Brigham Institutional Review Board 
Intervention/Interaction Detailed Protocol 
 
Version 2021.06.10 
 
Page 39 of 40 
 
 

Mass General Brigham Institutional Review Board 
Intervention/Interaction Detailed Protocol 
 
Version 2021.06.10 
 
Page 40 of 40 
APPENDIX B 
Prohibited Medications/Treatment 
 
 
Restrict use of Moderate or Strong CYP3A4 Inhibitors (Ibutamoren as a Victim)  
 
Clinical Impact 
 
Concomitant use of Ibutamoren with moderate or strong CYP3A4 inhibitors increases 
Ibutamoren systemic exposures, which may increase the risk of adverse reactions. 
 
Protocol language 
 
Exclude participants who require the chronic use of drugs that are known to be moderate or 
strong CYP3A4 inhibitors. If a brief course of a moderate or strong CYP3A4 inhibitor is 
required during the study, Ibutamoren can be discontinued and restarted immediately after 
four half-lives after discontinuation of the moderate or strong CYP3A4 inhibitor. 
 
Examples  
Moderate inhibitors 
aprepitant, ciprofloxacin, conivaptan, crizotinib, 
cyclosporine, diltiazem, dronedarone, 
erythromycin, fluconazole, fluvoxamine, imatinib, 
tofisopam, verapamil  
Strong inhibitors 
boceprevir, cobicistat, danoprevir and ritonavir, elvitegravir 
and ritonavir, grapefruit juice, indinavir and ritonavir, 
itraconazole, ketoconazole, lopinavir and ritonavir, 
paritaprevir and ritonavir and (ombitasvir and/or 
dasabuvir), posaconazole, ritonavir, saquinavir and 
ritonavir, telaprevir, tipranavir and ritonavir, telithromycin, 
troleandomycin, voriconazole 
 
Restrict use of Moderate or Strong CYP3A4 Inducers (Ibutamoren as a Victim)  
 
Clinical Impact 
 
Concomitant use of Ibutamoren with moderate or strong CYP3A4 inducers may decrease 
ibutamoren systemic exposures, which may impact efficacy in patients. 
 
Protocol language 
Exclude participants who require the chronic use of drugs that are known to be moderate or 
strong CYP3A4 inducers. If a brief course of a moderate or strong CYP3A4 inducer is 
required during the study, Ibutamoren can be discontinued and restarted immediately after 
discontinuation of the offending drug. 
 
Examples  
Moderate inducers 
bosentan, efavirenz, etravirine, phenobarbital, 
primidone 
Strong inducers 
apalutamide, carbamazepine, enzalutamide, mitotane, 
phenytoin, rifampin, St. John’s wort  
 
Restrict use of P-gp Inhibitors (Ibutamoren as a Victim)  
 
Clinical Impact 
Concomitant use of Ibutamoren with strong P-gp inhibitors may limit absorption from 
oral administration and impact systemic exposures of Ibutamoren. 
 
Protocol language 
Exclude participants who require the chronic use of drugs that are known to be P-gp 
inhibitors. If a brief course of a P-gp inhibitor is required during the study, Ibutamoren can 
be discontinued and restarted immediately after discontinuation of the offending drug. 
 
Examples 
amiodarone, carvedilol, clarithromycin, dronedarone, itraconazole, lapatinib, lopinavir and 
ritonavir, propafenone, quinidine, ranolazine, ritonavir, saquinavir and ritonavir, telaprevir, 
tipranavir and ritonavir, verapamil