Pharmacogenomics of GLP1 Receptor Agonists

June 26, 2025 updated by: Simeon I. Taylor, University of Maryland, Baltimore
Healthy volunteers were recruited from the Old Order Amish population in Lancaster County, Pennsylvania. After providing informed consent, research participants were screened for eligibility. The clinical trial was designed as a randomized crossover study in which participants underwent two frequently sampled intravenous glucose tolerance tests - one after receiving a subcutaneous injection of saline and one after receiving a subcutaneous injection of rapid-acting exenatide (BYETTA). The study sought to determine whether genetic variants are associated with the magnitude of the effect of exenatide. However, because the study fell far short of its recruitment targets, it was under-powered to evaluate genetic association. Thus, the data analysis focused on testing the hypothesis that the order of testing (whether the placebo FSIGT was conducted before the exenatide-stimulated FSIGT or whether the FSIGTs were conducted in the reverse order) does not alter the magnitude impact of exenatide on responses to a frequently sampled iv glucose tolerance test.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Healthy volunteers were recruited from the Old Order Amish population in Lancaster County, Pennsylvania. After providing informed consent, research participants were screened for eligibility. The clinical trial was designed as a randomized crossover study in which participants underwent two frequently sampled intravenous glucose tolerance tests (FSIGT) - one after receiving a subcutaneous injection of saline and one after receiving a subcutaneous injection of rapid-acting exenatide (BYETTA). Based on data obtained from the FSIGT, participants' response to exenatide was assessed -- specifically, the effect of exenatide to enhance insulin secretion and accelerate metabolism of glucose. The study sought to determine whether genetic variants are associated with the magnitude of the effect of exenatide. However, because the study fell far short of its recruitment targets, it was under-powered to evaluate genetic association. Thus, the data analysis focused on testing the hypothesis that the order of testing (whether the placebo FSIGT was conducted before the exenatide-stimulated FSIGT or whether the FSIGTs were conducted in the reverse order) does not alter the magnitude impact of exenatide on responses to a frequently sampled iv glucose tolerance test.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
63

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Lancaster, Pennsylvania, United States, 17602
        • Amish Research Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Member of the Old Order Amish community in Lancaster County, Pennsylvania
  • BMI: 18-40 kg/sq.m.

Exclusion Criteria:

  • Known allergy to exenatide
  • History of diabetes, random glucose >200 mg/dL, or HbA1c > 6.5%
  • Significant debilitating chronic cardiac, hepatic, pulmonary, or renal disease or other diseases that the investigator judges will make interpretation of the results difficult or increase the risk of participation
  • Seizure disorder
  • Pregnant by self-report or known pregnancy within 3 months of the start of study
  • Currently breast feeding or breast feeding within 3 months of the start of the study
  • Estimated glomerular filtration rate <60 mL/min/1.73m2
  • Hematocrit <35%
  • Liver function tests greater than 2 times the upper limit of normal
  • Abnormal thyroid stimulating hormone
  • History of pancreatitis or pancreatic cancer. Personal or family history of medullary carcinoma of the thyroid.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Exenatide followed by saline
Participants were randomized to receive exenatide 15 min before the first frequently sampled iv glucose tolerance test and saline 15 min before the second frequently sampled iv glucose tolerance test
Drug: Exenatide Injection (before the first FSIGT)

Nurses administered exenatide (5 mcg) subcutaneously 15 minutes prior to conducting the first frequently sampled intravenous glucose tolerance test.

In this crossover study, participants will also be "crossed over" to receive saline rather than exenatide: Nurses administered saline (0.2 mL) subcutaneously 15 minutes prior to conducting a frequently sampled intravenous glucose tolerance test.

Other Names:
  • BYETTA
  • Exenatide
Other: Saline followed by exenatide
Participants were randomized to receive saline15 min before the first frequently sampled iv glucose tolerance test and exenatide15 min before the second frequently sampled iv glucose tolerance test
Drug: Exenatide injection before the second FSIGT)
Nurses administered exenatide (5 mcg) subcutaneously 15 minutes prior to conducting the second frequently sampled intravenous glucose tolerance test.
Other Names:
  • BYETTA
  • Exenatide

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Exenatide Effect on First Phase Insulin Secretion
Time Frame: 0-10 minutes
The ratio of the area-under-the-curve (AUC) for 1st phase insulin secretion in the exenatide-stimulated FSIGT divided by the AUC for 1st phase insulin secretion in the saline FSIGT.
0-10 minutes
Exenatide Effect on Glucose Disappearance Rate
Time Frame: 25-50 minutes

The ratio of the glucose disappearance rate (exenatide) divided by the glucose disappearance rate (placebo).

Glucose disappearance rates were calculated as the slope of the plot of the logarithm of the glucose concentration as a function of time.
25-50 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Glucose Disappearance Rate (Exenatide)
Time Frame: 25-50 minutes
The slope of the line plotting the logarithm of glucose concentrations as a function of time during the exenatide frequently sampled intravenous glucose tolerance test. The slope of the line was estimated as the slope of the least-squares fit to the data points between 25-50 minutes.
25-50 minutes
Glucose Disappearance Rate (Placebo)
Time Frame: 25-50 minutes
The slope of the line plotting the logarithm of glucose concentrations as a function of time during the placebo frequently sampled intravenous glucose tolerance test. The slope of the line was estimated as the slope of the least-squares fit to the data points between 25-50 minutes.
25-50 minutes
First Phase Insulin Secretion (Exenatide)
Time Frame: 0-10 minutes
The area under the curve for plasma insulin levels during a frequently sampled intravenous glucose tolerance test after participants received exenatide
0-10 minutes
First Phase Insulin Secretion (Placebo)
Time Frame: 0-10 minutes
The area under the curve for plasma insulin levels during a frequently sampled intravenous glucose tolerance test after participants received saline
0-10 minutes
Drug Effect on First-Phase Insulin Secretion (Genotype-specific)
Time Frame: 0 - 10 min during the FSIGT
The effect of exenatide to increase first-phase insulin secretion was defined as the ratio of area-under-the-curve (AUC) for insulin levels during the first 10 minutes of the exenatide-stimulated FSIGT divided by the AUC for first phase insulin secretion during the saline FSIGT..
0 - 10 min during the FSIGT
Exenatide's Effect on the Rate of Glucose-disappearance (Genotype Specific)
Time Frame: 25-50 min during the FSIGT
The rate of glucose disappearance was calculated as the slope of a least-squared line fitted to the logarithms of glucose concentrations during time 25-50 min of FSIGTs
25-50 min during the FSIGT

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Maryland, Baltimore

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Simeon I Taylor, MD, University of Maryland, Baltimore

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2016

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 30, 2018

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 31, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 23, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 6, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 10, 2023

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 1, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 26, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HP-00067574

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Subject to protection of confidential information of research participants, we will share data with qualified researchers.

IPD Sharing Time Frame

12 months after publication in a peer reviewed journal.

IPD Sharing Access Criteria

Must sign data transfer agreement to protect confidentiality of research participants.

Requester must be on faculty at an accredited academic institution such as a medical school.

IPD Sharing Supporting Information Type

  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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