Clinical trial NCT04941521
Conditions: Cocaine Use Disorder
Keywords: Cocaine use Exenatide Cocaine treatment
Sponsor: The University of Texas Health Science Center, Houston
Start date: 2021-06-24; Completion date: 2021-11-17
Enrollment: 3 participants; Allocation: NA; Intervention model: SINGLE_GROUP

Brief summary:
The purpose of this study is to collect information about whether exenatide (Bydureon) may be safe and helpful as a medication treatment for individuals who want to stop using cocaine.

Although exenatide (Bydureon) is approved by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes, it has not been approved by the FDA to treat cocaine use; therefore, it is called an investigational drug.

Detailed description:
Cocaine use continues to be a significant public health problem with limited treatment options and no approved pharmacotherapies. Glucagon-like peptide 1 (GLP-1) receptors are located in brain areas important for reward and, as such, appear to play a significant role in modulating addictive-like behaviors and drug use (Eren-Yazicioglu et al. 2020). Extended-release exenatide is a GLP-1 receptor agonist approved by the FDA for the treatment of type 2 diabetes. In preclinical studies, exenatide reduces cocaine-seeking and cocaine-taking behavior (Brunchmann et al. 2019). The effect of extended-release exenatide on cocaine use in patients with a cocaine use disorder (CUD) has not yet been investigated. A series of four case studies are being proposed to collect preliminary data on the feasibility, safety, and clinical effects of exenatide in treatment-seeking patients with CUD.

The U.S. is facing a re-emergence of cocaine as an epidemic drug, indicated by increases in availability, use, and overdose deaths following a previous period of decline (Maxwell 2020). Although significant strides have been made in medication development for the treatment of cocaine use disorder (CUD), no FDA-approved pharmacotherapies are currently available. NIDA's current strategic plan prioritizes efforts to accelerate CUD medication development by rigorously testing novel molecular targets based on a translational research approach. Emerging evidence supports the potential clinical utility of glucagon-like peptide 1 (GLP-1) receptor stimulation for the treatment of substance use disorders, including CUD.

GLP-1 is an incretin hormone that promotes insulin secretion from pancreatic beta cells. Current evidence shows that GLP-1 receptors are widely expressed in areas of the mesolimbic dopaminergic pathway where they regulate the rewarding value of food and drugs of abuse, including cocaine. Preclinical literature suggests that activation of GLP-1 receptors reduces the rewarding effects of cocaine and cocaine self-administration (e.g., Hernandez et al. 2018; Hernandez et al. 2019). In the human laboratory, acute cocaine administration decreases GLP-1 concentrations, with changes associated with subjective reinforcing responses to cocaine ("feeling high, anxious") (Bouhlal et al. 2017). Thus, there is compelling evidence to hypothesize that exenatide treatment will decrease cocaine use in individuals with CUD. In preparation for conducting a full-scale efficacy trial, the goal of the current proposal is to collect preliminary feasibility, safety, and clinical data on the effects of exenatide in series of four case studies.

Arms: arm 1: Participants will receive once weekly exenatide injections and drug counseling sessions.
Interventions: intervention 1: Exenatide 2 mg [Bydureon] intervention 2: Drug Counseling
Intervention descriptions: intervention 1: Exenatide will be purchased commercially as Bydureon® for subcutaneous (SC) injection and administered at a dose of 2 mg once a week for a total of 6 weeks. Each single-dose, dual-chamber pen contains 0.65 mg of diluent and 2 mg of exenatide, which remains isolated until mixed. intervention 2: Once weekly drug counseling sessions for cocaine use with trained masters-level therapists.

Protocol documents:
Prot_SAP_000.pdf: 
IRB NUMBER: HSC-MS-21-0241 
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Feasibility of exenatide, a GLP-1R agonist, for treating cocaine use disorder: A case series 
study 
 
NCT04941521 
 
Version Date: 06/03/2021 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


IRB NUMBER: HSC-MS-21-0241 
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Protocol Title: 
Feasibility of exenatide, a GLP-1R agonist, for treating cocaine use disorder: 
A case series study 
 
Principal Investigators: 
Joy Schmitz, PhD, Luba Yammine, PhD 
 
Co-Investigator: 
Michael Weaver, MD 
 
Study Coordinator: 
Jessica Vincent, QA Manager 
 
Population: 
N = 4, male/female, 18-60 years old 
 
Study Site: 
UTHealth Center for Neurobehavioral Research on Addiction (CNRA) 
 
Study Duration: 
12 months 
 
Subject Duration: 
7 weeks 
 
 
General Information 
Cocaine use continues to be a significant public health problem with limited treatment options and 
no approved pharmacotherapies. Glucagon-like peptide 1 (GLP-1) receptors are located in brain areas 
important for reward and, as such, appear to play a significant role in modulating addictive-like 
behaviors and drug use (Eren-Yazicioglu et al. 2020). Extended-release exenatide is a GLP-1 receptor 
agonist approved by the FDA for the treatment of type 2 diabetes. In preclinical studies, exenatide 
reduces cocaine-seeking and cocaine-taking behavior (Brunchmann et al. 2019). The effect of extended- 
release exenatide on cocaine use in patients with a cocaine use disorder (CUD) has not yet been 
investigated. We propose a series of four case studies to collect preliminary data on the feasibility, 
safety, and clinical effects of exenatide in treatment-seeking patients with CUD. 
 
Background Information 
The U.S. is facing a re-emergence of cocaine as an epidemic drug, indicated by increases in 
availability, use, and overdose deaths following a previous period of decline (Maxwell 2020). Although 
significant strides have been made in medication development for the treatment of cocaine use disorder 
(CUD), no FDA-approved pharmacotherapies are currently available. NIDA’s current strategic plan 
prioritizes efforts to accelerate CUD medication development by rigorously testing novel molecular 
targets based on a translational research approach. Emerging evidence supports the potential clinical 
utility of glucagon-like peptide 1 (GLP-1) receptor stimulation for the treatment of substance use 
disorders, including CUD. 
GLP-1 is an incretin hormone that promotes insulin secretion from pancreatic beta cells. Current 
evidence shows that GLP-1 receptors are widely expressed in areas of the mesolimbic dopaminergic 
pathway where they regulate the rewarding value of food and drugs of abuse, including cocaine. 
Preclinical literature suggests that activation of GLP-1 receptors reduces the rewarding effects of 
cocaine and cocaine self-administration (e.g., Hernandez et al. 2018; Hernandez et al. 2019). In the 
human laboratory, acute cocaine administration decreases GLP-1 concentrations, with changes 
associated with subjective reinforcing responses to cocaine (“feeling high, anxious”) (Bouhlal et al. 
2017).  Thus, there is compelling evidence to hypothesize that exenatide treatment will decrease


IRB NUMBER: HSC-MS-21-0241 
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Page 3 of 9 
 
cocaine use in individuals with CUD. In preparation for conducting a full-scale efficacy trial, the goal of 
the current proposal is to collect preliminary feasibility, safety, and clinical data on the effects of 
exenatide in series of four case studies. 
 
Study Objectives 
1. To evaluate the feasibility of using exenatide as a treatment for CUD. Primary outcome will be 
treatment completion, measured as attendance at the end-of-treatment (Week 6) timepoint. 
Secondary outcomes related to feasibility will include enrollment, attendance, retention, and 
overall acceptability, measured at study completion (Week 6) timepoint. 
2. To evaluate the safety of using exenatide as an adjunct treatment for CUD. Primary outcomes 
related to safety will include adverse events monitored at each clinic visit. 
3. To evaluate clinical effects of exenatide on cocaine use and addiction-related behaviors. 
Primary outcome related to clinical effects will be cocaine use as measured by urine drug 
screens at the end-of-treatment (Week 6) timepoint. Secondary outcomes related to clinical 
effects will include cocaine use as measured by self-report, craving, drug demand, and 
depressive and affective symptoms assessed during each visit. 
 
Study Design 
The study will employ a case series design with the intervention (extended-release exenatide) run 
as a single-arm open-label pilot.  The framework for this study is exploratory.  All participants will 
receive evidence-based standard of care outpatient treatment for CUD. Primary and secondary 
outcomes will undergo visual analysis to determine within-subject change as a function of treatment, 
along with simple descriptive statistics for the group as a whole. At this early planning stage of research 
on exenatide treatment, a larger scale RCT design was not considered appropriate for feasibility, ethical 
and methodological reasons. 
 
Study Population 
 
Inclusion criteria: 
1. between 18 and 60 years of age 
2. meet DSM-5 criteria for current cocaine use disorder as measured by the Structured Clinical 
Interview for DSM-5 (SCID: First 2015) 
3. have at least 1 cocaine-positive urine specimen (≥ 150 ng/mL) during intake 
4. be in acceptable health on the basis of interview, medical history and physical exam 
5. have hematology and chemistry laboratory tests that are within reference limits (±10%), with 
the following exception: pancreatic tests (lipase and amylase) must be within normal limits 
6. consent to use an acceptable method of birth control during study participation and for 
one month after discontinuation of the study medication. Non-hormonal methods of 
contraception are recommended, including barrier contraceptives (e.g., diaphragm, cervical 
cap, male condom) or intrauterine device (IUD). Steroid contraceptives if used with non- 
hormonal methods are acceptable 
7. be able to understand the consent form and provide written informed consent 
8. be able to provide the names of at least 2 persons who can generally locate their 
whereabouts 
 
Exclusion criteria: 


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1. current DSM-5 diagnosis for substance use disorder (of at least moderate severity) other 
than cocaine, marijuana, alcohol, or nicotine 
2. current alcohol use that meets for physiological dependence requiring detoxification or 
makes participation medically unsafe as determined by the medical director 
3. have a DSM-5 axis I psychiatric disorder, or anorexia nervosa, or neurological disease or 
disorder requiring ongoing treatment and/or making study participation unsafe (e.g., 
psychosis, dementia) 
4. significant current suicidal or homicidal ideation 
5. Type 1 or type 2 diabetes mellitus (previously diagnosed or indicated by HbA1C level of 
≥6.5%) 
6. have medical conditions contraindicating exenatide pharmacotherapy (e.g., personal or 
family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome 
type 2, severe gastrointestinal disease (severe gastroparesis), previous history of pancreatitis 
or risk of pancreatitis, creatinine clearance <45 or end stage renal disease, previous medically 
adverse reaction to exenatide or other GLP-1 receptor agonists) 
7. taking medications that could adversely interact with exenatide (e.g., oral or injectable 
blood glucose lowering medications) 
8. having conditions of probation or parole requiring reports of drug use to officers of the 
court 
9. impending incarceration 
10. pregnant or nursing for female patients 
 
Study Procedures 
The study site is the Treatment Research Clinic of the Center for Neurobehavioral Research on 
Addiction (CNRA), a university-supported center of excellence within the UTHealth Department of 
Psychiatry and Behavioral Sciences. Established and effective recruitment strategies at the CNRA include 
newspaper and radio ads, social media posts, referrals from local treatment professionals and former 
research patients. Those responding to recruitment ads are first screened by phone, then undergo a 
general intake evaluation protocol (HSC-MS-05-0322) consisting of a drug history and psychiatric 
evaluation (SCID), physical examination and laboratory testing (chemistry screen, complete blood count, 
urinalysis, and a 12 lead EKG) prior to signing informed consent to participate in a specific study. For the 
current study, participants who complete the general intake evaluation protocol and are determined to 
be eligible will be invited to participate. We expect to screen 10 participants in order to enroll four. 
All participants will receive six weeks of treatment as usual (TAU), consisting of standard 
psychosocial treatment for CUD, delivered by trained masters-level therapists at the CNRA. This 
treatment will include weekly in-person individual Drug Counseling sessions focusing on providing 
education and recovery support, according to a standard treatment manual (Crits-Christoph et al. 1999). 
The pharmacological intervention (extended-release exenatide) will be given as an add-on to TAU. 
Exenatide will be purchased commercially as Bydureon® for subcutaneous (SC) injection and 
administered at a dose of 2 mg once a week for a total of 6 weeks. Per the FDA-approved label, 2 mg of 
Bydureon is administered SC once a week, at any time of day and with or without meals. Exenatide is 
supplied as a powder with a solvent for once-weekly injection. Each single-dose, dual-chamber pen 
contains 0.65 mg of diluent and 2 mg of exenatide, which remains isolated until mixed. Between weekly 
injection visits, the therapist will conduct a brief (20 minute) phone check-in session with their client to 
assess functioning, provide support, and encourage ongoing participation. Participants will receive $15 
compensation for attending each weekly study visit plus $30 for attending the study completion visit at 
week 6. 


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Study medication risks and safety monitoring 
Rosenstock and colleagues evaluated extended release exenatide in non-diabetic subjects with and 
without prediabetes. The most common side effect of the treatment was nausea (25%), however, there 
were no differences in withdrawal rates due to nausea between the treatment and the placebo groups. 
No serious adverse effects were reported in this study (Rosenstock et al. 2010). A meta-analysis of six 
randomized controlled trials investigating the use of exenatide in overweight and obese subjects 
without diabetes reported that there were no serious adverse events in the included studies (Su et al. 
2016). There were no episodes of hypoglycemia in the studies that used hypoglycemia as an outcome. 
The most common adverse events in the exenatide group, included nausea, vomiting, diarrhea, 
constipation and abdominal distension. Another meta-analysis of the studies investigating GLP-1R 
agonists in overweight and obese subjects without diabetes reported that GLP-1R agonists did not 
increase the number of participants who withdrew or dropped out from studies (Zhang et al. 2015). 
Neither diarrhea nor hypoglycemia appeared more frequently in the GLP-1R agonist group than that in 
the control group; however, subjects assigned to GLP-1R agonists reported more nausea and vomiting 
than those in the control group. Collectively, these findings demonstrate that GLP-1R agonist therapy is 
safe in persons without diabetes, and that the side effect profile of GLP-1R agonists is similar among 
diabetes and non-DM patients. 
Risks associated with study medication will be minimized through careful assessment. During 
screening, participants will be assessed for contraindications for Bydureon: hypersensitivity to 
drug/class/components, diabetes mellitus type 1, history of pancreatitis, personal of family history of 
medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2, creatinine clearance <45 or 
ESRD. Screening will consist of a detailed medical history and physical exam and blood tests including 
complete blood count, complete metabolic panel, and pancreatic enzymes levels. Potential participants 
with diabetes mellitus type 1, creatinine clearance <45 or ESRD, abnormal levels of pancreatic enzymes, 
those with a history or at risk for pancreatitis, and those with personal and/or family history of thyroid 
C-cell tumor will be excluded from participation in this study. During the study, participants’ vital signs, 
overall wellbeing, and potential side effects of Bydureon will be assessed at each weekly visit, and finger 
stick blood glucose levels will be assessed prior to each dose of the medication. Subsequent doses of 
Bydureon will not be administered if any of the following occur: hypoglycemia (blood glucose <70 
mg/dL), severe injection site reaction, hypersensitivity reaction, anaphylaxis, angioedema, cholecystitis, 
and cholelithiasis or if the Study Physician (CoI, Dr. Michael Weaver) believes that there may be any 
reason to withhold exenatide. 
 
Assessment schedule 
 
Table 1 provides a summary of the outcome measures to be completed during the study. 
 
Intake 
Enrollment 
Treatment (week) 
0 
1 
2 
3 
4 
5 
6 
Informed consent 
X 
Eligibility determination (per HSC-MS-05-0322) 
X 
Safety labs (amylase/lipase/HbA1C) 
X 
Outcome variables 
Treatment participation 
X 
X 
X 
X 
X 
X 
Satisfaction Survey 
X 
Side effects/AE 
X 
X 
X 
X 
X 
X 
Vital signs/weight 
X 
X 
X 
X 
X 
X 
X 
Finger-stick glucose monitoring 
X 
X 
X 
X 
X 
X 


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Carbon monoxide (CO) 
X 
X 
X 
X 
X 
X 
X 
Breath alcohol concentration (BAC) 
X 
X 
X 
X 
X 
X 
X 
Urine pregnancy test 
X 
X 
X 
X 
X 
Urine drug screen (UDS) 
X 
X 
X 
X 
X 
X 
X 
Cocaine Timeline Followback (TLFB) 
X 
X 
X 
X 
X 
X 
X 
Craving 
X 
X 
X 
X 
X 
X 
X 
Drug Demand 
X 
X 
Beck Depression Inventory II (BDI-II) 
X 
X 
X 
Positive/Negative Affect Schedule (PANAS) 
X 
X 
X 
Visual analogue scale (VAS) of drug effects 
X 
X 
X 
X 
X 
X 
X 
Diet 
X 
X 
Intervention 
Exenatide injection 
X 
X 
X 
X 
X 
X 
Drug counseling session 
X 
X 
X 
X 
X 
X 
Phone check-in session 
X 
X 
X 
X 
X 
X 
 
Description of Outcome Measures 
• 
Treatment participation will be measured according to number of weekly clinic visits attended 
and completion rates at end-of-treatment (week 6). 
• 
A Satisfaction Survey will be used to assess treatment acceptability using a 4-point Likert scale 
to rate services on various dimensions, such as quality, adequacy, appropriateness, and 
accessibility. We will adapt this measure to include acceptability ratings related to exenatide 
pharmacotherapy. 
• 
Side effects (i.e., nausea, vomiting, dyspepsia, diarrhea, constipation, headache, injection-site 
pruritus, injection-site nodule) and AEs will be assessed at each clinic visit by Dr. Yammine. 
• 
Vital signs will be assessed at each clinic visit and will include systolic and diastolic blood 
pressure, heart rate, respiratory rate, oral temperature, and weight. 
• 
Finger-stick blood glucose levels will be assessed prior to each dose of exenatide (if blood 
glucose is <70 mg/dL, subsequent doses of exenatide will not be administered). 
• 
CO breath testing will follow standard measurement procedures and will be used to evaluate 
smoking status (Sandberg et al. 2011). 
• 
BAC breath testing using a breathalyzer will estimate recent alcohol consumption and be used 
to judge signs of alcohol-related impairment that may influence study participation. 
• 
Urine pregnancy test will be performed prior to the first dose of exenatide, every two weeks 
thereafter, and at the last day of treatment. 
• 
UDS levels of the cocaine metabolite, benzoylecgonine (BE) ≥ 300 ng/mL will be coded as 
“positive” for cocaine use. Standard UDS collection methods used at the CNRA will be followed. 
• 
TLFB will be administered as a self-report measure of substance use frequency and quantity. In 
addition to cocaine, other substances (e.g., alcohol, marijuana, nicotine) will be assessed using 
standard TLFB interview methodology (Sobell et al. 1996). 
• 
Craving will be assessed using the Brief Substance Craving Scale (BSCS: Somoza et al. 1995), a 
16-item, self-report measure of craving for cocaine and other substances over a 24 hour period. 
Intensity, duration, and frequency of craving are rated on a 0-4 point Likert scale. The sum of 
the three scores yields a craving composite measure. 
• 
Drug Demand will be used as a measure of reward sensitivity. We will administer the 
computerized cocaine purchasing task in which participants are asked to make repeated choices 
between hypothetical purchases of cocaine at varying prices (Bruner and Johnson 2014). 


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• 
BDI-II and PANAS will be used to measure depressive symptoms and affective experiences, 
respectively. 
• 
VAS will be used to measure subjective effects of cocaine experienced during the previous 
week. Participants will be asked to rate on a 100 mm line (0=not at all; 100=extremely) the drug 
effects they experienced, e.g., euphoria, high, anxious. 
• 
Diet will be assessed at baseline and at the end of treatment using the Automated Self- 
Administered 24-hr Dietary Assessment Tool (ASA24: Kirkpatrick et al. 2014) 
 
Data and Safety Monitoring 
The Principal Investigators (Schmitz, Yammine) will be responsible for knowing the policies of the 
local IRB. In this capacity, they will maintain accurate documentation of CPHS correspondence and 
reports and oversee the handling of all possible study-related adverse events. The CNRA has 
longstanding data collection and safety monitoring system in place that will be available for the 
proposed study. This includes staff training, manual driven processes, weekly audit of data 
collection/entry, medical screening with results reviewed by on-site nurse and physician, use of 
standardized assessments, continued medical monitoring during treatment, use of a certified (CLIA) 
analytical laboratory to perform urine toxicology testing, procedures to monitor medication compliance, 
collaboration with the statistician who oversees data analysis and system management. The PI will 
assure that the above systems are in place and functioning properly for the duration of the study. 
The CNRA has a Data and Safety Monitoring Board (DSMB) that provides independent oversight of 
all active protocols involving patient safety data. DSMB members include Drs. Jan Blalock (UT-MDA 
Cancer Center), Edward Fann (Baylor College of Medicine-Psychiatry), Daryl Ishaq Shorter (Baylor 
College of Medicine), and Claudia Pedrozo (UTHealth Department of Pediatrics). The current study will 
be included in the list of protocols reviewed annually (and as needed) by the DSMB. 
Adverse events (AE) will be reported to CPHS. Serious AEs will be reported immediately (verbally 
within 24 hours) to CPHS and the DSMB. A written report will follow as soon as possible but in no more 
than three days and will contain information regarding the date of the AE, description of the AE, severity 
rating (Grade 1 to 4), assessment of cause, whether the AE indicates an increased risk for current or 
future subjects, and whether changes to the informed consent form are necessary. 
 
Statistics 
Primary analyses will report results related to feasibility, safety and clinical outcomes. Individual 
data will be plotted graphically and visual analysis will be used to assess change over time in treatment. 
Summary descriptive statistics will be reported on the sample as a whole. Given the small sample size 
used in case studies, quantitative statistical testing is not appropriate. Results will be used to determine 
if a subsequent larger scale trial is warranted. 
 
Ethics 
IRB approval will be sought from CPHS. Participation in this study is completely voluntary. All 
participants will be informed of the nature of the procedures and associated risks. Participants will be 
informed that they can withdraw from the study at any time and that this will have no adverse impact 
on the study or on their own future treatment. Individuals will participate in the study only after they 
provide verbal and signed consent. Trained research personnel will obtain consent in a private room 
where participants feel comfortable. Informed consent will be documented in writing via the 
participants’ and investigators’ signatures. 
 
Data handling, record keeping, quality assurance 


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• 
The study protocol and all data generated will be held in strict confidence by the Investigators and 
will not be released to any unauthorized third party without prior written consent/approval by the 
participant. 
• 
The CNRA PIs and Quality Manager, Jessica Vincent, have substantial experience in the design and 
implementation of data management procedures that provide accurate recording and storage of 
data, participant confidentiality, and timely analysis. 
• 
The CNRA treatment research clinic has a workstation room with four (4) dedicated computerized 
systems for research participants to complete digital questionnaires and self-report forms under 
supervision of authorized personnel. 
• 
CNRA research computers are equipped with the major data management and analysis software 
programs needed for the proposed project. All data files are automatically backed up daily. 
• 
Information Technology at UTHealth provides onsite computer support staff to ensure timely and 
reliable services. 
 
Publication Plan 
We will publish research results in a peer-reviewed journal and/or present findings at a scientific 
conference. 


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