GLUCOSE-MGH: Genetic Links Understood Through Challenge With Oral Semaglutide Exposure at MGH (GLUCOSE-MGH)

April 3, 2026 updated by: Josephine Li, MD, Massachusetts General Hospital
The goal of this research study is to evaluate the pathophysiologic mechanisms by which genetic variation impacts response to an FDA-approved medication commonly used to treat type 2 diabetes called oral semaglutide (Rybelsus) and to characterize the physiological response to a mixed meal tolerance test (MMTT) before and after a 14-day treatment with oral semaglutide. The investigators will do this by measuring factors in the blood, such as sugars, fats, metabolites, and proteins, after eating a standardized breakfast meal at the first visit and after taking 14 doses of oral semaglutide over two weeks before the second study visit. The food (mixed meal breakfast) we will be studying is specially prepared to contain a set amount of protein, carbohydrates, and fat. The investigators hypothesize that understanding how the acute biochemical response to oral semaglutide differs by genetic variation will generate insight into drug mechanisms and type 2 diabetes pathophysiology.

Study Overview

Detailed Description

On day 1 (Visit 1), the research subject will present to the Translational and Clinical Research Center (TCRC) after an overnight fast. We will obtain informed consent, check vital signs, take anthropometric measurements, and draw fasting blood work through an intravenous catheter. The subject will then be provided a standard mixed meal to be consumed within 30 minutes. Additional blood will be drawn at the time of meal completion (0 minutes), as well as 5, 15, 30, 60, 90, and 120 minutes following the meal. During study days 3-15, the subject will take 7 mg of oral semaglutide once daily. On day 16 (Visit 2), the research subject will return to the TCRC. During this visit, the subject will take the final (14th) dose of semaglutide, receive fasting blood work, and receive another mixed meal with subsequent blood draws at several time points over 120 minutes.

Study Type

Interventional

Enrollment (Estimated)

125

Phase

  • Phase 4

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Recruiting
        • Massachusetts General Hospital
        • Contact:
        • Principal Investigator:
          • Josephine Li, MD

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Males or non-pregnant females
  2. Ages 18-65 (inclusive)
  3. Able/willing to give consent
  4. Span the metabolic range between normal glycemia and pre-diabetes (fasting glucose of 100-125 mg/dL based on chart review of existing laboratory data)

Exclusion Criteria:

  1. Currently taking medications or intending to take medications for diabetes
  2. Currently taking medications or intending to take medications that affect glycemic parameters, such as glucocorticoids, growth hormone, or fluoroquinolones
  3. Personal history of intestinal malabsorption, bariatric surgery, celiac disease, gallbladder disease, or pancreatitis
  4. Personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2
  5. Estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 per the Modification of Diet in Renal Disease equation
  6. History of cirrhosis and/or aspartate aminotransferase or alanine aminotransferase more than 3x upper limit of normal
  7. Dietary restrictions preventing consumption of a MMTT
  8. Women who are pregnant, nursing, or at risk of becoming pregnant
  9. Participation in other interventional studies during the current study

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: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: GLUCOSE-MGH Study

Day 1: Mixed meal tolerance test

Day 3-15: 7 mg oral semaglutide, once daily

Day 16: 1 dose of 7 mg oral semaglutide, Mixed meal tolerance test in the presence of semaglutide

Semaglutide is the only oral glucagon-like peptide 1 receptor agonist (GLP-1 RA) approved for treatment of type 2 diabetes. Participants will receive 7 mg of oral semaglutide once daily for 14 days in between Visit 1 and Visit 2.
The MMTT is developed by the Metabolism and Nutrition Metabolic Kitchen at the MGH TCRC. The meal is a high-calorie, high-carbohydrate and moderate-to-high glycemic index challenge composed of commonly consumed breakfast food items. It provides nearly 90 grams of carbohydrates and mimics an oral glucose challenge. The participants will undergo a MMTT at Visit 1 and Visit 2.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Insulin response to oral semaglutide treatment
Time Frame: 15 days
Investigators will measure the change in insulin area under the curve (AUC) over 120 minutes of the MMTT, calculated using the trapezoidal method, between Visit 1 and Visit 2 as an index of response to oral semaglutide, and compare this outcome by genotype at selected loci.
15 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Fasting glucose response to oral semaglutide treatment
Time Frame: 15 days
Investigators will measure the change in fasting glucose over 120 minutes of the MMTT, between the two visits, and compare this outcome by genotype at selected loci.
15 days
Cumulative glucose response to oral semaglutide treatment
Time Frame: 15 days
Investigators will measure the change in glucose area under the curve (AUC) over 120 minutes of the MMTT, between the two visits, and compare this outcome by genotype at selected loci.
15 days
Baseline incretin level
Time Frame: 120 minutes during Visit 1
Investigators will measure levels of GLP-1 during the length of the baseline MMTT (120 minutes) that takes place on Visit 1, and compare changes in the baseline levels by genotype at selected loci.
120 minutes during Visit 1

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Josephine Li, MD, MGH

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)

March 12, 2024

Primary Completion (Estimated)

May 31, 2027

Study Completion (Estimated)

May 31, 2027

Study Registration Dates

First Submitted

August 9, 2023

First Submitted That Met QC Criteria

August 18, 2023

First Posted (Actual)

August 21, 2023

Study Record Updates

Last Update Posted (Actual)

April 6, 2026

Last Update Submitted That Met QC Criteria

April 3, 2026

Last Verified

April 1, 2025

More Information

Terms related to this study

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.

Yes

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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