A Study of Tirzepatide (LY3298176) in Participants With Type 1 Diabetes Mellitus and Overweight or Obesity

September 1, 2026 updated by: Eli Lilly and Company

A Phase 1, Investigator- and Participant- Blinded, Randomized, Placebo-Controlled, Single-Dose Study to Investigate the Impact of Tirzepatide on Gastric Emptying in Adult Participants With Type 1 Diabetes Mellitus and Overweight or Obesity

The main purpose of this study is to learn more how tirzepatide affects stomach emptying in participants with Type 1 Diabetes Mellitus (T1DM) and overweight or obesity.

Participation in this study will last about 8 weeks, including screening and follow-up.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

18

Phase

  • 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 Contact

  • Name: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
  • Phone Number: 1-317-615-4559
  • Email: LillyTrials@Lilly.com

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Miami, Florida, United States, 33172
        • Clinical Pharmacology of Miami
        • Principal Investigator:
          • Angel Lamas
        • Contact:
          • Phone Number: (305) 817-2900

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

No

Description

Inclusion Criteria:

  • Have a diagnosis of type 1 diabetes mellitus (T1DM) and have been treated with insulin for at least 1 year prior to screening
  • Have a body mass index (BMI) greater than or equal to 25.0 kilograms per square meter (kg/m2) at screening
  • Are of stable weight, that is a self-reported change of 5 kg or less, for at least 90 days prior to screening

Exclusion Criteria:

  • Participants who have a known clinically significant gastric emptying abnormality
  • Have undergone weight loss surgery such as gastric bypass (bariatric) surgery or restrictive bariatric surgery
  • Have known allergies or intolerance to acetaminophen, tirzepatide, or glucagon-like peptide-1 (GLP-1) receptor agonists

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: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tirzepatide + Acetaminophen
Participants will receive tirzepatide administered subcutaneously (SC) and acetaminophen administered orally.
Drug: Tirzepatide
Administered SC.
Other Names:
  • LY3298176
Drug: Acetaminophen
Administered orally.
Placebo Comparator: Placebo + Acetaminophen
Participants will receive placebo administered SC and acetaminophen administered orally.
Drug: Placebo
Administered SC.
Drug: Acetaminophen
Administered orally.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Pharmacokinetics (PK): Time of Maximum Observed Drug Concentration (Tmax) of Acetaminophen
Time Frame: Predose on Day 1 through 36 hours post dose
Predose on Day 1 through 36 hours post dose
PK: Area Under the Concentration Versus Time Curve from Time Zero to Time t (AUC0-tlast) of Acetaminophen
Time Frame: Predose on Day 1 through 36 hours post dose
Predose on Day 1 through 36 hours post dose
PK: Maximum Observed Drug Concentration (Cmax) of Acetaminophen
Time Frame: Predose on Day 1 through 36 hours post dose
Predose on Day 1 through 36 hours post dose

Secondary Outcome Measures

Outcome Measure
Time Frame
PK: Area Under the Concentration Versus Time Curve from Time Zero to Infinity (AUC0-∞) of Tirzepatide
Time Frame: Predose on Day 1 through Day 29
Predose on Day 1 through Day 29
PK: Area Under the Concentration Versus Time Curve from Time Zero to Time t (AUC0-tlast) of Tirzepatide
Time Frame: Predose on Day 1 through Day 29
Predose on Day 1 through Day 29
PK: Maximum Observed Drug Concentration (Cmax) of Tirzepatide
Time Frame: Predose on Day 1 through Day 29
Predose on Day 1 through Day 29
PK: Time of Maximum Observed Drug Concentration (Tmax) of Tirzepatide
Time Frame: Predose on Day 1 through Day 29
Predose on Day 1 through Day 29

Collaborators and Investigators

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

Sponsor

Eli Lilly and Company

Investigators

  • Study Director: Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST), Eli Lilly and Company

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 (Estimated)

September 1, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

September 1, 2026

First Submitted That Met QC Criteria

September 1, 2026

First Posted (Actual)

September 4, 2026

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

September 1, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 27861
  • I8F-MC-GPJI (Other Identifier: Eli Lilly and Company)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

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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