Clinical trial NCT01529060
Conditions: Maple Syrup Urine Disease
Keywords: phenylbutyrate MSUD Buphenyl-TM
Sponsor: Brendan Lee
Start date: 2013-02-01; Completion date: 2017-12-01
Enrollment: 20 participants; Allocation: RANDOMIZED; Intervention model: CROSSOVER

Brief summary:
The investigators have learned in past research that the drug phenylbutyrate can decrease the amounts of branched chain amino acids and their byproducts in the bloodstreams of healthy volunteer patients and also patients with certain disorders of protein breakdown including maple syrup urine disease. Through this study, the investigators will try to find out how well phenylbutyrate (NaPBA), also known by name brand "Buphenyl-TM", decreases BCAA and branched chain keto chain acids in the blood of patients with MSUD. The investigators hope is that through this research the investigators will be better able to treat these patients.

Subjects with MSUD will take phenylbutyrate (NaPBA) in powder form for a two-week treatment period and powder placebo, a substance with no effect on the body, for a two-week treatment period. They will be given the same amount of powder and undergo the same laboratory testing during both of the two-week treatment periods. The results will be compared once the study is over.

Detailed description:
Maple syrup urine disease is a severe inborn error of amino acid metabolism caused by deficiency of the mitochondrial branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) resulting in the accumulation of branched-chain amino acids (BCAA) (isoleucine, leucine, and valine) and their corresponding branched-chain alpha-ketoacids (BCKA) \[alpha-keto-beta-methylvalerate (KMV), alpha-ketoisocaproate (KIC), and alpha-ketoisovalerate(KIV)\] in tissues and plasma. The disorder typically manifests with potentially lethal episodes of intoxication presenting with acute neurological deterioration, feeding problems, weight loss, and a maple syrup odor to the urine. Current treatment is based on dietary manipulations with protein restriction and a synthetic formula with reduced BCAA content. However, mental and social impairment are still present in the majority of these patients in spite of dietary management.

Our study seeks to investigate the potential small molecule inhibition of the kinase that regulates BCKDC by applying a novel activity of sodium phenylbutyrate (NaPBA), in MSUD. Sodium phenylbutyrate is has been used to treat patients with urea cycle disorders (UCDs). In our extensive studies with UCDs, we noted that patients on therapy with NaPBA had decreased plasma levels of BCAA. This led us to hypothesize that NaPBA has effects on BCAA metabolism.

This will be a single-site, randomized, active-controlled, double-blind, cross-over study designed to enroll subjects with MSUD. Subjects will be randomly assigned to receive either sodium phenylbutyrate (PB) or placebo for 2 weeks, and then crossed over to receive the other treatment for 2 weeks.

If study findings show sodium phenylbutyrate lowers BCAA and BCKA levels in these patients, it may prove to be an effective adjunct treatment for these patients. A treatment option that could prevent or decrease the accumulation of BCAA and BCKA during states of catabolism induced by fasting or intercurrent illnesses, and thereby minimize or prevent the neurologic sequelae and loss of human potential that result, would greatly benefit society.

Arms: arm 1: Study Drug arm 2: Placebo powder
Interventions: intervention 1: Phenylbutyrate intervention 2: Placebo powder
Intervention descriptions: intervention 1: Dosage of phenylbutyrate powder will be 500 mg/kg/day in patients weighing less than 20kg and 10 g/m2/day in larger patients in four divided doses per day, the standard UCD dose studied in our preliminary studies, for 14 days. intervention 2: Dosage of inactive placebo powder will be 500 mg/kg/day in patients weighing less than 20kg and 10 g/m2/day in larger patients in four divided doses per day for 14 days. Subjects will receive the same amount of powder for each arm of the study.

Protocol documents:
Prot_000.pdf: 
Title of the study:Phenylbutyrate Therapy in maple Syrup Urine 
Disease
NCT01529060
Date document submitted : October 16, 2017


Section C:  Background Information 
 
Maple syrup urine disease (MSUD; OMIM 248600) is a severe inborn error of amino acid metabolism 
caused by deficiency of the mitochondrial branched-chain alpha-ketoacid dehydrogenase complex 
(BCKDC) resulting in the accumulation of branched-chain amino acids (BCAA) (isoleucine, leucine, and 
valine) and their corresponding branched-chain alpha-ketoacids (BCKA) [alpha-keto-beta-methylvalerate 
(KMV), alpha-ketoisocaproate (KIC), and alpha-ketoisovalerate(KIV)] in tissues and plasma. The relative 
prevalence of the condition in the general population in the US is 1 in 150,000. However, in some 
isolated populations like the Mennonites, the prevalence is is much higher (1:386). The disorder typically 
manifests with potentially lethal episodes of intoxication presenting with acute neurological deterioration, 
feeding problems, weight loss, and a maple syrup odor to the urine. These episodes usually occur during 
states of catabolism induced by fasting or intercurrent illnesses and result primarily from the increases in 
plasma concentrations of leucine and its alpha-ketoacid. Based on its severity, MSUD has been 
classified into five clinical subtypes: 1) "classic" neonatal severe form, 2) "intermediate¨ form, 3) 
"intermittent" form, 4) "thiamine-responsive" form, and 5) "E3-deficient with lactic acidosis" form. 
Although the correlation between clinical severity and degree of residual BCKDC activity is often 
inconsistent, the later onset intermediate and intermittent forms are usually associated with some degree 
of residual activity, while the classic form usually exhibits very low or no BCKDC activity. Current 
treatment is based on dietary manipulations with protein restriction and a synthetic formula with reduced 
BCAA content. However, mental and social impairment are still present in the majority of these patients 
in spite of dietary management.   
The block in BCAA metabolism that results in MSUD occurs at the second step, the rate limiting step 
catalyzed by the enzyme complex BCKDC. The complex consists of three catalytic components: a 
decarboxylase (E1) composed of two E1alpha and two E1beta subunits, a transacylase (E2) core of 24 
identical lipoate bearing subunits, and a dehydrogenase (E3) existing as a homodimer. The subunits of 
the complex are encoded by four nuclear genes, synthesized in the cytosol, and imported in the 
mitochondria where assembly occurs. Mutations in the genes encoding the E1alpha, E1beta, and E2 
subunits result in an MSUD phenotype while mutations in the E3 subunit cause a different phenotype. 
Regulation of enzymatic activity depends on the phosphorylation status of the E1alpha subunit that is 
specified by a kinase (BDK) which inactivates BCKDC and by a mitochondrial matrix resident type 2C 
phosphatase gene, PP2Cm, that activates it. There appears to be no correlation between the molecular 
defects and the severity of the clinical presentation. 
In theory residual activity in this complex could be enhanced by altering the phosphorylation status of the 
E1alpha subunit. While this approach would not be effective in "null" activity patients, patients with even 
low residual activity may benefit with potential decrease in frequency of decompensation, improved 
rescue therapy during periods of decompensation and/or improved protein tolerance. Moreover, as 
BCKDC is located in almost all body tissues, even small increases in BCKDC activity may be effective. 
In general, it has been recognized that enzyme activity in vitro and DNA mutation do not generally 
predict clinical severity or level of residual activity in vivo. 
Our study seeks to investigate the potential small molecule inhibition of the kinase that regulates BCKDC 
by applying a novel activity of an FDA-approved compound, sodium phenylbutyrate (NaPBA), in MSUD. 
Sodium phenylbutyrate is an FDA-approved drug that has been used to treat patients with urea cycle 
disorders (UCDs). In our extensive studies with UCDs, we noted that patients on therapy with NaPBA 
had decreased plasma levels of BCAA. This was subsequently confirmed in the ongoing Rare Diseases 
Clinical Research Network study "Longitudinal Study of Urea Cycle Disorders". This lead us to 
hypothesize that NaPBA has effects on BCAA metabolism.   
Previously in H- 9281, Branched Chain Amino Acids and Regulation of Body Protein Turnover, we 
performed a pilot open-label study of sodium phenylbutyrate in three healthy volunteers and five MSUD 
subjects with clinical history of late onset disease to test whether PB might have effects on BCAA and 
the downstream BCKA. The design of the pilot study was a fixed-sequence, cross-over study with three 
days of steady state protein intake without drug followed by one day washout and then three days of PB 
treatment. BCAA and BCKA were determined at three time points on the last day of each study period. 
Upon treatment with phenylbutyrate, a reduction in both BCAA and BCKA was detected in all three 
control subjects (p< 0.05) and three (patients 3, 4 and 5) out of the five MSUD patients (p< 0.05). In 
these three MSUD responders, the leucine reduction ranged from 24% to 34% of the baseline levels. 
There was no clear correlation between the levels of residual enzymatic activity with the response of 
plasma BCAA and their BCKA to phenylbutyrate. Additionally, two of the responders (patients 4 and 5) 


carried E2 mutations whereas the third (patient 3) responder carried an E1alpha mutation. These data 
suggest that irrespective of the subunit affected, MSUD patients have the potential to respond to sodium 
phenylbutyrate. 
  
Section D:  Purpose and Objectives 
    
The purpose of this protocol is to investigate the efficacy of sodium phenylbutyrate in the treatment of 
patients with maple syrup urine disease. The primary outcome measurements will be Cmax and Area 
Under the Curve (AUC) for BCAA and BCKA on the last study day of each intervention period.  
  
Section E:  Protocol Risks/Subjects 
E1.  Risk Category 
    Category 2: Research involving greater than minimal risk, but presenting the prospect of direct benefit to 
the individual subjects. 
E2.  Subjects 
Gender: 
    Both 
Age: 
    Adolescent (13-17 yrs), Adult (18-64 yrs), Child (3-12 yrs), Geriatric (65+ yrs) 
Ethnicity: 
    All Ethnicities 
Primary Language: 
    English, Spanish 
Groups to be recruited will include: 
    Asymptomatic patients with chronic conditions, healthy; Patients 
Which if any of the following vulnerable populations will be recruited as subjects? 
    Children, Cognitively impaired 
Vulnerable populations require special protections.  How will you obtain informed consent, protect subject 
confidentiality, and prevent undue coercion? 
    
Anytime consent is obtained, it is incumbent on the individual obtaining the consent to ascertain whether 
the potential participant and his/her legal representative understand all aspects of the study. Obtaining 
informed consent is an interactive process with questions asked of both the Investigator and potential 
participant. A participating investigator or his designee will obtain informed consent and sign the consent 
form along with the parent/legal representative. 
Some subjects may be cognitively impaired, a common sequela of hyperammonemia. In the case of 
cognitively impaired adults (chronologically over 18 years of age) whose mental age is younger than 18 
years of age, informed consent will be obtained from the subject's legal representative after study 
rationale, risks, benefits and procedures have been discussed. Assent for these adult subjects whose 
mental age is less than 18 years of age will be documented in the subject's medical record. If the 
cognitively impaired participant is chronologically between the ages of 7 and 17, the parent or legal 
guardian will consent and assent will be waived. See the Waiver of Adult and Child Assent forms 
attached in Section S. 


Information from three sources will assist investigators in assessing whether a cognitively impaired 
subject has the capacity to give assent: the medical records available, the subject’s legal representative 
and the subject himself. Medical records may contain developmental testing results stating mental age, 
and parents and guardians often know this information. Finally, it will be the subject’s responses during 
the consent process itself which will disclose whether he/she understands the study and is therefore able 
to give his/her assent. The subject should be able to accurately state study purpose, procedures and 
risks in his/her own words, and verbally agree to participation in order for assent to be granted. Mere 
failure to object will not be taken as subject assent. See assurance documents attached in Section S. 
Subjects may also include affected children between 3 and 17 years of age who are capable of 
completing study procedures. If the participant’s mental age is the same as their actual age, we will 
follow the usual consent procedures with those 7-17 years old giving assent. Assent will be obtained if it 
is determined that the subject understands all aspects of the study. Assent will be documented by the 
subject's signature on the "Subject" line on the consent form. We will waive the requirement for assent of 
subjects less than 7 years of age. See assurance documents attached in Section S. 
 
For Spanish-speaking subjects, a translator will be available to aid in the translation and explanation of 
the entire protocol and to answer questions. In these cases, short form Spanish consent will be used in 
addition to the full English consent form.  
 
All tests except those performed within Texas Children's Hospital will be coded. The database linking 
coded samples to subject identity will be password-protected, access to which will be limited to essential 
study staff. Personal identifying information will be recorded in a secure database and consents or other 
pertinent clinical information stored in a secure file at TCH. Identifiable subject-specific data will not be 
reported in any public format, nor will it be reported to any third party to which Baylor may contract 
E3.  Pregnant woman/fetus 
Will pregnant women and/or fetuses (as described in 45 CFR 46 Subpart B) be enrolled in the research? 
    No 
E4.  Neonates 
Will neonates of uncertain viability or nonviable neonates (as described in 45 CFR 46 Subpart B) be 
enrolled in the research? 
    No 
E5.  Children 
Will children be enrolled in the research? 
    Yes 
  
Section F:  Design/Procedure 
F1.  Design 
Select one category that most adequately describes your research: 
    z.z) ARCHIVED DO NOT USE - Other:  Drug Phase 2/3 
Discuss the research design including but not limited to such issues as: probability of group assignment, 
potential for subject to be randomized to placebo group, use of control subjects, etc. 
    
This will be a single-site, randomized, active-controlled, double-blind, cross-over study designed to enroll 
subjects with MSUD. Subjects will be randomly assigned to receive either sodium phenylbutyrate (PB) or 
placebo for 2 weeks, and then crossed over to receive the other treatment for 2 weeks. Randomization 
and initial treatment group assignment will be performed by the Investigational Pharmacy Services at 
Texas Children’s Hospital in a 1:1 ratio using established randomization procedures.   
 


No unaffected control subjects will be studied. The "active-control" design of the study through which 
each MSUD patient/subject receives sodium phenylbutyrate (PB) or placebo for 2 weeks, then crosses 
over to receive the other treatment for 2 weeks, enables each subject's response to sodium 
phenylbutyrate to be evaluated by comparing data obtained while on NaPBA to data obtained while 
he/she was receiving a placebo.  
Inclusion Criteria: 
    
Patients must be 3 years or older at enrollment with a diagnosis of maple syrup urine disease (MSUD) 
confirmed by the presence of plasma alloisoleucine (>5 micromol/L) and/or genetic testing showing 
mutations in both alleles of any subunit of BCKDHA (E1alpha subunit gene, MSUD type 1A), BCKDHB 
(E1beta subunit gene, MSUD type 1B), or DBT (E2 subunit gene, MSUD type 2). Subjects must be 
capable of completing study procedures, including taking oral or G-tube medication, and have a history 
of compliance to diet and treatment. 
Exclusion Criteria: 
    
Subjects may not have used sodium phenylbutyrate within 30 days of Visit 1. They may not have an 
active infection (viral or bacterial) or any condition which may exacerbate their MSUD causing metabolic 
decompensation. Enrollees cannot have any clinical or laboratory abnormality of Grade 3 or greater 
according to the Common Terminology Criteria for Adverse Events v3.0 (CTCAE) (or for conditions not 
covered by the CTCAE, a severe or life-threatening toxicity). Within the 24 hours prior to Visit 1, subjects 
may not have taken any medications known to significantly affect renal clearance or to increase protein 
catabolism. Subjects may not participate if they have a known hypersensitivity to phenylacetate or 
phenylbutyrate or creatinine levels 1.5 times or more ULN. 
Since a total of 53 mL will be drawn over Days 14 and 15 of both treatment periods, subjects weighing 
less than 13.6 kg or 30 pounds will not be enrolled.  
F2.  Procedure 
    
Subjects with confirmed MSUD will be studied in the General Clinical Research Center at Texas 
Children's Hospital using a cross-over design with two 14-day treatment periods. In order to confirm 
subject's diagnosis, a review of pertinent medical records will be performed prior to study enrollment.   
 
Data collection occurs during three or four study visits, depending on the scheduling of the treatment 
periods. (Subjects will have two visits per treatment period if the periods are not contiguous, and three 
visits if the treatment periods are back-to-back.)  
 
Day 1 of Treatment Period 1 is an outpatient visit to the GCRC Outpatient Clinic. After informed consent 
is granted, randomization will be performed. Study staff will then: • Perform a physical examination • 
Record medical history, concomitant medications and a 24-hour diet recall to plan future inpatient meals. 
• Measure vital signs, height and weight. • Collect blood for safety laboratory assessments (complete 
blood count (CBC), Chem 7, and urinalysis). • Perform urine pregnancy test, if applicable. • Collect single 
blood sample for plasma amino acids and branched chain alpha ketoacids. • Collect single blood sample 
for pharmacokinetics (4-phenylbutyric acid/phenylbutyrate, phenylacetylglutamine and phenylacetic 
acid/phenylacetate) and for storage. This sample for storage will be saved so that, if necessary, analysis 
can be repeated and /or findings verified. • Calculate NaPBA Dose . • Dispense Treatment Period 1 
study drug/placebo. • Administer Initial Treatment Period 1 study drug/placebo. • Monitor subject for 
anaphylactic reaction for one hour prior to discharge. 
 
Study drug/placebo will be administered orally three times daily. Sodium phenylbutyrate dosage will be 
500 mg/kg/day in patients weighing less than 20kg and 10 g/m2/day in larger patients in three divided 
doses per day, the standard UCD dose studied in our preliminary studies. The maximum allowed adult 
dose of phenylbytrate is 2 grams per day. The Investigational Pharmacy Service at Texas Children's 
Hospital will dispense the sodium phenylbutyrate/placebo powder. Subjects will be sent home with a 
scales on which to weigh the study drug/placebo. It is then mixed with food and/or water or flavored 
syrup and administered orally or through nasogastric or gastrostomy tube. Subjects will receive the same 
amount of study drug/placebo for each arm of the study, and only the Investigational Pharmacy will know 
when the subject is receiving study drug and when they are taking placebo.  
 
Other medications as well as the subject's therapeutic diet will be continued as prescribed throughout 


the study. Because Buphenyl-TM can sometimes cause stomach upset, you will be started on ranitidine 
(Zantac-TM).  
 
 
 
This initial visit will take about 4 hours. 
 
Subjects will be requested to perform a 3-day diet record for Days 11, 12 and 13 of both treatment 
periods. 
 
On Day 14 of Treatment Period 1, subjects will return for a one-night inpatient stay on the GCRC. After 
an AM admission, study staff will: • Perform a physical examination. • Document concomitant 
medications, intercurrent illness and adverse events. • Measure vital signs, weight and height. • Collect 
blood for safety laboratory assessments (complete blood count (CBC), comprehensive metabolic panel 
and urinalysis). • Perform urine pregnancy test, if applicable. • Begin 24-hour blood sampling (8 samples 
over 24 hours) to measure plasma amino acids and branched chain alpha ketoacids as primary 
endpoints. • Begin 24-hour blood sampling (8 samples over 24 hours) to measure pharmacokinetics(4-
phenylbutyric acid/phenylbutyrate, phenylacetylglutamine and phenylacetic acid/phenylacetate and for 
storage. These samples for storage will be saved so that, if necessary, analyses can be repeated and /or 
findings verified. • Begin 24-hour urine collection to be tested to measure amino acid and branched chain 
keto acid levels.   
 
During the morning of Day 15/Treatment Period 1, 24-hour blood sampling and urine collection are 
completed and subject's vital signs are taken. Subjects may be discharged home to return at a later time 
to begin Treatment Period 2 or may begin Treatment Period 2 with the first dose of study drug/placebo 
with lunch.   
 
Procedures on Day 1 of Treatment Period 2 include: • Documentation of adverse events and 
concomitant medications. • Measurement of vital signs, height and weight. • Collection of single blood 
sample for plasma amino acids and branched chain alpha ketoacids. • Collection of single blood sample 
for pharmacokinetics (4-phenylbutyric acid/phenylbutyrate, phenylacetylglutamine and phenylacetic 
acid/phenylacetate) and for storage. This sample for storage will be saved so that, if necessary, analyses 
can be repeated and /or findings verified. • Initiation of Treatment Period 2 study drug/placebo. • 
Monitoring of subject for anaphylactic reaction for one hour prior to discharge. 
 
If treatment periods are not contiguous, the following procedures will also be performed: • Collection of 
blood for safety laboratory assessments (complete blood count (CBC), Chem 7, and urinalysis). • 
Performance of urine pregnancy test, if applicable.  
 
Subjects return to the GCRC on Day 14 of Treatment Period 2 for another overnight inpatient admission 
to the GCRC. Study staff will: • Perform a physical examination. • Document concomitant medications, 
intercurrent illness and adverse events. • Measure vital signs, height and weight. • Collect blood for 
safety laboratory assessments (complete blood count, comprehensive metabolic panel and urinalysis). • 
Perform urine pregnancy test, if applicable. • Begin 24-hour blood sampling (8 samples over 24 hours) to 
measure plasma amino acids and branched chain alpha ketoacids as primary endpoints. • Begin 24-hour 
blood sampling (8 samples over 24 hours) to measure pharmacokinetics(4-phenylbutyric 
acid/phenylbutyrate, phenylacetylglutamine and phenylacetic acid/phenylacetate and for storage. These 
samples for storage will be saved so that, if necessary, analyses can be repeated and /or findings 
verified. • Begin 24-hour urine collection to be tested to measure amino acid and branched chain keto 
acid levels.  
 
On the morning of Day 15/Treatment Period 2, subject is discharged after 24-hour blood sampling and 
urine collection are completed and vital signs are taken.  
  
Section G:  Sample Size/Data Analysis 
 See Separate document attached 
Section H:  Potential Risks/Discomforts 


H1.  Potential Risks/Discomforts 
Describe and assess any potential risks/discomforts; (physical, psychological, social, legal, or other) and 
assess the likelihood and seriousness of such risks: 
    
The risks associated with venipuncture are minimal. Adverse events in clinical trials of sodium 
phenylbutyrate include the following; amenorrhea/irregular menstrual cycles (23%), decreased appetite 
(4%), body odor, taste aversion (3%), abdominal pain, gastritis, nausea, vomiting, constipation, rectal 
bleeding, peptic ulcer disease, pancreatitis (one patient), aplastic anemia (one patient), arrhythmia (one 
patient), edema, renal tubular acidosis, depression, rash, headache, syncope, weight gain (2%). 
Neurotoxicity has been reported in cancer patients taking 250-300 mg/kg/day of intravenous 
phenylacetate but was reversed upon discontinuance of the drug. Laboratory abnormalities have 
included; acidosis (14%), alkalosis or hyperchloremia (7%), hypophosphatemia or hyperuricemia (2%), 
hypernatremia or hypokalemia (1%), hypoalbuminemia (11%), decreased total protein (3%), anemia 
(9%), leukopenia or leukocytosis (4%), and thrombocytopenia (1%). 
According to accepted guidelines, the maximum amount of blood to be drawn over a 24-hour period is 
3% of total blood volume if the subject is an outpatient, and 5% of total blood volume if the subject is an 
inpatient. The maximum amount of blood which can be safely drawn from research participants in any 
one-month period should not exceed 10% of the total blood volume.  
 
Since a total of 53 mL will be drawn over Days 14 and 15 of both treatment periods, only subjects 
weighing more than 13.6 kg and 30 pounds can be enrolled. Since a total of 124 mL will be drawn over 
the entire study, only subjects weighing 18.2 kg or 40 pounds may be studied with admissions occurring 
within one month's time. A record of total blood volume withdrawn during each admission will be 
maintained in the subject's medical record. 
H2.  Data and safety monitoring plan 
     Do the study activities impart greater than minimal risk to subjects? 
    
    Yes 
 
NOTE:  The answer to the questions in H2 requires the completion of the form: 'Section H – Data and 
Safety Monitoring Plan' as an attachment in Section S. 
H3.  Coordination of information among sites for multi-site research 
Is the BCM Principal Investigator acting as the SPONSOR-INVESTIGATOR for this multi-site research? 
        No or Not Applicable 
Is BCM the COORDINATING CENTER for this multi-site research? 
        No or Not Applicable 
  
Section I:  Potential Benefits 
Describe potential benefit(s) to be gained by the individual subject as a result of participating in the planned 
work. 
    
One potential benefit to the individual subject participating in this research is the possible introduction an 
efficacious adjunct treatment for their maple syrup urine disease. Since sodium phenylbutyrate is already 
an FDA-approved drug, the implementation of positive findings in the clinical arena could be fast. 
Participants may benefit directly from this project if findings indicate NaPBA is effective in reducing 
BCAA and BCKA levels and should be included in their treatment regimen. 
Describe potential benefit(s) to society of the planned work. 
    
Maple syrup urine disease is a severe inborn error of amino acid metabolism which results in the 
accumulation of BCAA and BCKA in tissues and plasma. This accumulation leads to neurological 
deterioration, feeding problems, weight loss and a maple syrup odor to the urine. In the most severe 
form, MSUD can damage the brain during times of physical stress (such as infection, fever, or not eating 


for a long time). Even in the mildest form, repeated periods of physical stress can cause mental 
retardation and high levels of leucine. Current treatment is based on dietary manipulations with protein 
restriction and a synthetic formula with reduced BCAA content. However, mental and social impairment 
are still present in the majority of these patients in spite of dietary management. 
If study findings show sodium phenylbutyrate lowers BCAA and BCKA levels in these patients, it may 
prove to be an effective adjunct treatment for these patients. A treatment option that could prevent or 
decrease the accumulation of BCAA and BCKA during states of catabolism induced by fasting or 
intercurrent illnesses, and thereby minimize or prevent the neurologic sequelae and loss of human 
potential that result, would greatly benefit society.  
Do anticipated benefits outweigh potential risks? Discuss the risk-to-benefit ratio. 
    
In weighing the potential risks of this research against the possible benefits of applying a novel activity of 
the FDA-approved compound sodium phenylbutyrate (NaPBA) in MSUD, we believe that the benefits 
outweigh the associated risks. 
  
Section J:  Consent Procedures 
J1.  Waiver of Consent 
Will any portion of this research require a waiver of consent and authorization? 
    No 
  
J1a.  Waiver of requirement for written documentation of Consent 
Will this research require a waiver of the requirement for written documentation of informed consent? 
    No 
J2.  Consent Procedures 
Who will recruit subjects for this study? 
    PI 
PI's staff 
Describe how research population will be identified, recruitment procedures, any waiting period between 
informing the prospective participant and obtaining consent, steps taken to minimize the possibility of 
coercion or undue influence and consent procedures in detail. 
    
Patients may hear about the study through the MSUD Family Support Group (the primary patient 
advocacy organization for this diagnosis), from their physicians in Baylor's Metabolic Clinic at TCH or 
from physicians at other metabolic treatment centers across the country. Past and current patients of Dr. 
Lee may be contacted directly by study staff for possible recruitment. Subjects referred by other 
physicians will be approached by study staff only after the treating physician receives permission from 
the patient/parents for them to do so. Subject/Parental permission will be documented by the referring 
physician on the Authorization for Study Staff to Contact form attached in Section S. This form must be 
received by study staff before they will contact the potential subject. All prospective participants will be 
asked to sign a medical records release form along with the study consent form prior to screening. 
Medical records may be obtained to confirm MSUD diagnosis and affirm that none of the exclusionary 
conditions are present.  
A one-page synopsis of the study usng verbiage from the IFC has been prepared to hand out to potential 
participants at the MSUD Family Support Group meeting during the summer of 2014. This synopsis is 
attached in section S. 
 
Consent forms will be given/mailed to potential participants prior to enrollment so that they have ample 
time to review the information and ask questions about the study. Investigators will ensure that the 


participant or their legally authorized representative understand the information provided and obtain 
informed consent. One parent may sign the consent as this study involves greater than minimal risk, but 
presents the prospect of direct benefit to the individual subjects. We may obtain consent from subjects 
up to three weeks prior to admission in order to register and randomize the subject so that the 
Investigational Pharmacy Service at Texas Children’s Hospital can prepare the assigned treatment 
drug/placebo ahead of time.  
 
For subjects who live outside of the Houston area or are unable to come to the Medical Center to 
complete this consent process in person, telephone consent is obtained. When obtaining consent over 
the telephone, study staff will follow 21CFR50.27 instructions for obtaining verbal consent. The 
"screening script" will be the text of the approved consent form. With a witness listening, the entire 
consent form will be reviewed with the potential enrollee. After informed consent is given, this consent 
will be documented by the presenter and the witness on a consent form. In these cases, the informed 
consent process is always repeated in person prior to admission when the subject is actually in Houston. 
The subject/parent signs the consent form at that time, and this signed consent is saved in the study file 
along with the phone consent copy signed by the presenter and the witness. 
Are foreign language consent forms required for this protocol? 
    Yes 
Which of the following ways will you document informed consent in languages other than English? 
    Short-Form consent documents 
J3.  Privacy and Intrusiveness 
Will the research involve observation or intrusion in situations where the subjects would normally have an 
expectation of privacy? 
    Yes 
J4.  Children 
Will children be enrolled in the research? 
    Yes 
J5.  Neonates 
Will non-viable neonates or neonates of uncertain viability be involved in research? 
    No 
J6.  Consent Capacity - Adults who lack capacity 
Will Adult subjects who lack the capacity to give informed consent be enrolled in the research? 
    Yes 
J7.  Prisoners 
Will Prisoners be enrolled in the research? 
    No 
  
Section K:  Research Related Health Information and Confidentiality 
Will research data include identifiable subject information? 
    Yes 
Information from health records such as diagnoses, progress notes, medications, lab or radiology findings, 
etc. 


    Yes 
Specific information concerning alcohol abuse: 
    No 
Specific information concerning drug abuse: 
    No 
Specific information concerning sickle cell anemia: 
    No 
Specific information concerning HIV: 
    No 
Specific information concerning psychiatry notes: 
    Yes 
Demographic information (name, D.O.B., age, gender, race, etc.): 
    Yes 
Full Social Security #: 
    No 
Partial Social Security # (Last four digits): 
    No 
Billing or financial records: 
    No 
Photographs, videotapes, and/or audiotapes of you: 
    No 
Other:  
    No 
At what institution will the physical research data be kept? 
    
Each subject will have a hardcopy research file/chart which will stored in a locked file cabinet in the 
Study Coordinator's office on the 15th floor of the Clinical Care Center. These records will not be de-
identifed or coded. This is a single-site study, and no case report forms or reporting of patient 
demographics or personal health information to a central coordinating center will occur. Proof of 
diagnosis and eligibility, along with paper copies of safety lab and plasma amino acid results and other 
research-related documents will be kept in these secure files. 
How will such physical research data be secured? 
    Each subject will have a hardcopy research file/chart which will stored in a locked file cabinet in the 
Study Coordinator's office on the 15th floor of the Clinical Care Center. 
At what institution will the electronic research data be kept? 
    The electronic research data will be kept at Texas Children's Hospital in a password-protected electronic 
medical record system.  
Such electronic research data will be secured via BCM IT Services- provided secured network storage of 
electronic research data (Non-Portable devices only): 
    Yes 
Such electronic research data will be secured via Other:  


    
Yes, (describe below): 
The electronic research data will be kept at Texas Children's Hospital in a password-protected electronic 
medical record system. 
Will there be anyone besides the PI, the study staff, the IRB and the sponsor, who will have access to 
identifiable research data? 
    No 
Please describe the methods of transmission of any research data (including PHI, sensitive, and non-
sensitive data) to sponsors and/or collaborators. 
    
Blood samples sent to Virginia Tech will be coded. The key for these samples will be kept in Research 
Assistant¿s password-protected computer in the Genetics Office on the 15th floor of the Clinical Care 
Center at TCH. Safety labs and plasma amino acids will be sent to TCH Pathology and labeled with PHI. 
These results will be in the password-protected TCH medical record system as well as the research 
chart locked in the file cabinet in the Study Coordinator's office. 
  
Will you obtain a Certificate of Confidentiality for this study? 
    No 
Please further discuss any potential confidentiality issues related to this study. 
    N/A 
  
Section L:  Cost/Payment 
Delineate clinical procedures from research procedures. Will subject's insurance (or subject) be responsible 
for research related costs? If so state for which items subject's insurance (or subject) will be responsible 
(surgery, device, drugs, etc). If appropriate, discuss the availability of financial counseling. 
    
Costs of outpatient care and laboratory analyses at TCH and study medication will be encumbered by 
the study. For out-of-town families, the study will pay shipping costs, but will not reimburse for any 
expenses related to sample collection.  
 
Distribution Plan: Participants will be compensated $200 following completion of each arm of the study. 
Total compensation for the study will be $400. The costs of parking in a Texas Medical Center parking 
lot will be paid by the study through validation stickers and parking tokens distributed at the time of 
subject visit. Meals can be provided for the subject by the GCRC when he/she is actually on the GCRC 
and the cost of other meals for the subject and accompanying family member can be reimbursed within a 
month of receipt submission. (Continued below.) 
If subjects will be paid (money, gift certificates, coupons, etc.) to participate in this research project, please 
note the total dollar amount (or dollar value amount) and distribution plan (one payment, pro-rated payment, 
paid upon completion, etc) of the payment. 
Dollar Amount: 
    400 
Distribution Plan: 
    
If subject is unable to pay for meals, food vouchers for the Food Court at the Clinical Care Center may 
be given. Travel to and from BCM for study visits will also be covered. This includes reimbursement for 
fuel and food purchased during the trips. The study will pay for one family member to travel with the 
subject, and any air travel and hotel stays will be arranged by study staff and paid by the study. There 
are no caps or limits to travel reimbursements, and when possible Mercy Medical Airlift which provides 
charitable medical air transportation will be used. A check for study compensation and reimburse for 
expenses incurred will be mailed to the subject after each two-week study treatment period is completed. 
The check is usually issued and mailed to the subject within one month of submission of the receipts.  


  
Section M:  Genetics 
How would you classify your genetic study? 
    
Discuss the potential for psychological, social, and/or physical harm subsequent to participation in this 
research. Please discuss, considering the following areas: risks to privacy, confidentiality, insurability, 
employability, immigration status, paternity status, educational opportunities, or social stigma. 
    
Will subjects be offered any type of genetic education or counseling, and if so, who will provide the 
education or counseling and under what conditions will it be provided? If there is the possibility that a 
family's pedigree will be presented or published, please describe how you will protect family member's 
confidentiality? 
    
  
Section N:  Sample Collection 
SAMPLE:  Blood 
What is the purpose of the sample collection? 
    
Blood will be collected for safety labs (complete blood count and comprehensive metabolic panel or 
Chem 7). These will be processed at Texas Children's Hospital Pathology. Plasma amino acids, 
branched chain alpha-ketoacids, and NaPBA metabolites (4-phenylbutyric acid/phenylbutyrate, 
phenylacetylglutamine and phenylacetic acid/phenylacetate) will also be obtained. The plasma amino 
acids will be processed at Baylor, and the branched chain keto acids and NaPBA metabolites will 
tranferred to outside labs for processing. With each blood draw for plasma amino acids, branched chain 
alpha-ketoacids and NaPBA metabolites, a sample will be collected for storage. These samples for 
storage will be saved so that, if necessary, analyses can be repeated and /or findings verified. 
For blood draws, specify the amount drawn, in teaspoons, at each visit and across the course of the 
subjects entire participation time. 
    
On Day 1/Treatment Period 1 lab analysis will include: complete blood count with differential and 
platelets, chem 7, plasma amino acids, branched chain alpha-ketoacids and NAPBA metabolites (4-
phenylbutyric acid/phenylbutyrate, phenylacetylglutamine and phenylacetic acid/phenylacetate). In 
addition, a 1-mL sample will be drawn for storage. A total of 11 mL (just over 2 teaspoons) of blood will 
be drawn during this study visit.  
 
On Days 14-15/Treatment Period 1 baseline lab analysis will include: complete blood count with 
differential and platelets, chem 7, plasma amino acids (baseline or pre-dose, 2-hr, 4-hr, 8-hr, 12-hr, 16-
hr, 20-hr and 24-hr samples), branched chain alpha-ketoacids (baseline or pre-dose, 2-hr, 4-hr, 8-hr, 12-
hr, 16-hr, 20-hr and 24-hr samples), and NAPBA metabolites (baseline or pre-dose, 2-hr, 4-hr, 8-hr, 12-
hr, 16-hr, 20-hr and 24-hr samples). In addition, a 1-mL sample will be drawn for storage at baseline or 
pre-dose, 2-hrs, 4-hrs, 8-hrs, 12-hrs, 16-hrs, 20-hrs and 24-hrs. A total of 53 mL (10 and a half 
teaspoons) of blood will be drawn during this study visit.   
 
If the treatment periods are contiguous, Day 1/Treatment Period 2 lab analysis will be: plasma amino 
acids, branched chain alpha-ketoacids and NAPBA metabolites (4-phenylbutyric acid/phenylbutyrate, 
phenylacetylglutamine and phenylacetic acid/phenylacetate). In addition, a 1-mL sample will be drawn 
for storage. These tests can be performed on 7 mL (1 and a half teaspoons) of blood. But, if the 
treatment periods are not contiguous, the safety labs (complete blood count with differential and platelets 
and Chem 7) will need to be repeated, bringing the total amount of blood to be drawn for the visit to 11 
mL (just over 2 teaspoons).   
 
On Day 14-15/Treatment Period 2 lab analysis will include: complete blood count with differential and 


platelets, comprehensive metabolic panel, plasma amino acids (pre-dose, 2-hr, 4-hr, 8-hr, 12-hr, 16-hr, 
20-hr and 24-hr samples), branched chain alpha-ketoacids (pre-dose, 2-hr, 4-hr, 8-hr, 12-hr, 16-hr, 20-hr 
and 24-hr samples), and NAPBA metabolites (pre-dose, 2-hr, 4-hr, 8-hr, 12-hr, 16-hr, 20-hr and 24-hr 
samples). In addition, a 1-mL sample will be drawn for storage at pre-dose, 2-hrs, 4-hrs, 8-hrs, 12-hrs, 
16-hrs, 20-hrs and 24-hrs. A total of 53 mL (10 and a half teaspoons) of blood will be drawn during this 
study visit.   
 
The total amount of blood to be drawn during the entire study will be 124 mL (about 25 teaspoons) if 
treatment periods are contiguous, and 128 mL (about 26 teaspoons) if they are not.  
 
The maximum amount of blood that can safely be drawn over a 24-hour period is 5% of total blood 
volume. Since we will be drawing 53 mL over a 24-hour period (Days 14 and 15 of both treatment 
periods), and 5% of the estimated blood volume of patients weighing 13.6 kg (30 pounds) is 54 mL, we 
will limit study enrollment to those weighing more than 13.6 kg or 30 pounds.   
 
There are also guidelines about the maximum amount of blood which can safely be drawn from research 
participants in any one-month period. Current standards indicate that the maximum amount of blood 
which can be safely drawn from research participants in any one-month period should not exceed 10% 
of the total blood volume. If participants complete both 14-day treatment periods contiguously, a total of 
124 mL blood would be drawn over a month's time. Since 10% of the estimated blood volume of patients 
weighing 18.2 kg (40 pounds) is 130 mL, it would be unsafe for subjects weighing less than 18.2 kg to 
complete the treatment periods within a one-month period. Subjects who fall within the 13.6 kg to 18.2 kg 
weight range will not be allowed to complete both treatment periods contiguously. They must have a 
wash-out period of more than 2 weeks between treatment cycles so that the amount of blood drawn 
within any one-month period is less than 124 mL.  
Is there the possibility that cell lines will be developed with this sample?No 
Sample will be obtained from: 
    Research Labs 
Will the sample be stripped of identifiers? 
    No 
If sample will be released outside the hospital: 
Will sample be released to anyone not listed as an investigator on the protocol? Will the information be 
identifiable, coded or de-identified? 
    Yes. Samples will be coded. 
Will sample material be sold or transferred to any third parties? Will the information be de-identified? 
    
BCKA samples will be sent to Susan Hutson, Department of Human Nutrition, Foods and Exercise, 
Virginia Polytechnic and State University, for processing. If the sample for storage is used, part of that 
sample will be sent to Dr. Hutson for measurement of branched chain alpha-ketoacids. Samples for 
NAPBA metablites will be sent to Children's National Medical Center for processing. 
If sample will be banked for future use: 
Where will the sample be banked and for how long? 
    
The blood samples drawn for storage may be stored in locked freezers as long as the study is still in 
progress. All frozen samples will be labeled with initials and subject study number only.  
Does the banking institution have an approved policy for the distribution of samples? 
    Yes. 
If the entire sample will NOT be used during the course of this research study: 


Will the remaining tissue be discarded? If not what will be done with the remaining sample after study 
completion and how long will the sample be kept? 
    Any samples not used during the course of this study will be discarded at the time of study completion.  
Will samples be made available to the research subject (or his/her medical doctor) for other testing? 
    No 
If a subject withdraws from the study: 
Will subject have the option to get the remaining portion of their sample back? 
    No 
Will samples be destroyed? If not, will they be kept anonymously? What will happen to the sample if the 
subject revokes authorization? 
    If the subject revokes authorization prior to sample processing, all samples including the sample for 
storage will be destroyed.  
Will data obtained from their sample be deleted? What will happen to the sample if the subject revokes 
authorization? 
    
If the safety labs have been processed, the results will remain in the subject's electronic medical record. 
Data from other samples including the sample for storage will be deleted. Only data from safety labs will 
be recorded in the subject's medical record. 
Will study data or test results be recorded in the subject's medical records? 
    Yes 
Will results of specific tests and/or results of the overall study be revealed to the research subject and or 
his/her doctor? 
    
Results of safety labs can be revealed to the subject as the study is conducted. The results of the 
branched chain alpha-ketoacids, and NaPBA metabolites (4-phenylbutyric acid/phenylbutyrate, 
phenylacetylglutamine and phenylacetic acid/phenylacetate) will be revealed to the subject at study 
completion. The subject may reveal these results to his/her doctor. 
Please identify all third parties, including the subject's physician, to receive the test results. 
    No third parties will receive the test results.  
  
SAMPLE:  Urine 
What is the purpose of the sample collection? 
    Urine for urinalysis and, if applicable, pregnancy. A 24-hour collection will be performed. This urine will 
be tested to measure amino acids and branched chain keto acids. 
For blood draws, specify the amount drawn, in teaspoons, at each visit and across the course of the 
subjects entire participation time. 
    N/A 
Is there the possibility that cell lines will be developed with this sample?No 
Sample will be obtained from: 
    Research Labs 
Will the sample be stripped of identifiers? 
    No 
If sample will be released outside the hospital: 


Will sample be released to anyone not listed as an investigator on the protocol? Will the information be 
identifiable, coded or de-identified? 
    The 24-hour collections will be coded and released to Dr. Susan Hutson. 
Will sample material be sold or transferred to any third parties? Will the information be de-identified? 
    No 
If sample will be banked for future use: 
Where will the sample be banked and for how long? 
    
The urine samples may be stored in locked freezers until shipped to Dr. Hutson. All samples will be 
labeled with initials and subject study number only. Only BCM study staff will be able to link labeled 
samples to individual subjects. 
Does the banking institution have an approved policy for the distribution of samples? 
    Yes 
If the entire sample will NOT be used during the course of this research study: 
Will the remaining tissue be discarded? If not what will be done with the remaining sample after study 
completion and how long will the sample be kept? 
    Pregnancy and urinalysis testing will be performed by Department of Pathology at TCH, and remaining 
sample discarded. All urine sent to Dr. Hutson will be used during the course of this study.  
Will samples be made available to the research subject (or his/her medical doctor) for other testing? 
    No 
If a subject withdraws from the study: 
Will subject have the option to get the remaining portion of their sample back? 
    No 
Will samples be destroyed? If not, will they be kept anonymously? What will happen to the sample if the 
subject revokes authorization? 
    If subject revokes authorization before sample is processed, it will be destroyed.  
Will data obtained from their sample be deleted? What will happen to the sample if the subject revokes 
authorization? 
    Results of pregnancy testing and urinalysis will not be deleted, and will remain in subject's medical 
record. Results obtained by Dr. Hutson will be deleted.  
Will study data or test results be recorded in the subject's medical records? 
    Yes 
Will results of specific tests and/or results of the overall study be revealed to the research subject and or 
his/her doctor? 
    
Results of pregnancy test and urinalysis will be revealed to the research subject. Subject may forward 
them on to his/her doctor. Results of testing performed by Dr. Hutson can be revealed to the subject at 
study completion.  
Please identify all third parties, including the subject's physician, to receive the test results. 
    No third parties will receive the results.  
  


Section O:  Drug Studies 
Does the research involve the use of ANY drug* or biologic? (*A drug is defined as any substance that is 
used to elicit a pharmacologic or physiologic response whether it is for treatment or diagnostic purposes) 
    Yes 
Does the research involve the use of ANY gene transfer agent for human gene transfer research? 
    No 
O1.  Current Drugs 
Drug :  Buphenyl  
  
Is this study placebo-controlled? 
    Yes 
If yes, be sure that you justify the use of the placebo for this research in the space below. 
    
The "active-control" design of the study through which each MSUD patient/subject receives sodium 
phenylbutyrate (PB) or placebo for 2 weeks, then crosses over to receive the other treatment for 2 
weeks, enables each subject's response to sodium phenylbutyrate to be evaluated by comparing data 
obtained while on NaPBA to data obtained while he/she was receiving a placebo.  
Will the research involve a radioactive drug that is not approved by the FDA? 
    No 
  
Section P:  Device Studies 
     Does this research study involve the use of ANY device? 
        No 
  
Section Q.  Consent Form(s) 
None 
  
Section R:  Advertisements 
Mode of Advertising:  Other: flyers for metabolic dietitians and physicians and patients 
Exact language of Advertisement: 
    
A flyer outlining the study may be sent to metabolic dietitians and physicians at other metabolic centers. 
This flyer is attached to the protocol in section S. A patient flyer for metabolic physicians and dietitians to 
hand out to potential subjects has also been attached in section S. 
  
 

SAP_001.pdf: 
Title: Phenylbutyrate therapy for Maple Syrup Urine Disease
NCT01529060
Date Document submitted October 16, 2017


MSUD	  clinical	  trial	  methods	  
	  
Descriptive	  statistics	  were	  calculated	  using	  standard	  methods.	  Mean,	  median	  and	  the	  
dospspersion	  around	  the	  measures	  of	  central	  tendency	  were	  calculated	  for	  the	  primary	  
endpoints.	  The	  cross-­‐over	  analysis	  was	  carried	  out	  following	  the	  standard	  procedures	  
previously	  described	  (Piantadosi	  Steven.	  Clinical	  Trials:	  A	  Methodologic	  Perspective.	  2nd	  
ed.	  Hobaken,	  NJ:	  John	  Wiley	  and	  Sons,	  Inc).	  To	  evaluate	  the	  first-­‐order	  carry-­‐over	  effect,	  
measured	  amino	  acids	  AUC	  values	  from	  both	  arms	  were	  summated	  together	  for	  each	  
subject.	  The	  summated	  values	  were	  compared	  between	  the	  groups	  that	  received	  drug	  
first	  vs	  placebo	  first	  by	  two	  sample	  t-­‐test.	  This	  was	  performed	  to	  test	  for	  any	  carryover	  
effect.	  The	  effect	  of	  treatment	  was	  then	  calculated	  by	  a	  two-­‐sample	  t-­‐test	  to	  compare	  
the	  differences	  in	  AUC	  of	  BCAA	  over	  the	  periods	  of	  treatment	  for	  the	  two	  treatment	  
sequences.	  To	  account	  for	  the	  relatedness	  in	  the	  amino	  acid	  measurements	  within	  each	  
subject	  during	  the	  two	  treatment	  periods,	  linear	  mixed	  model	  was	  used	  to	  account	  for	  
the	  non-­‐independence	  in	  sequential	  measurements.	  For	  model	  building,	  the	  fixed	  
component	  was	  constructed	  by	  using	  amino	  acid	  AUC	  as	  dependent	  variable.	  For	  the	  
independent	  variables,	  the	  model	  included	  treatment	  and	  a	  dichotomized	  variable	  
defined	  by	  whether	  the	  first	  period	  of	  treatment	  is	  placebo	  or	  not.	  For	  the	  mixed	  effect	  
component,	  patient	  ID	  was	  used	  as	  a	  grouping	  factor	  to	  estimate	  random	  effect	  arising	  
from	  the	  characteristics	  of	  each	  subject.