RecruitingPhase 1

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

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

Lead sponsor

Eli Lilly and Company

Asset

Tirzepatide

Subcutaneous · GLP-1 / GIP dual

Listed sites

Recruiting sites

Estimated enrollment

Study population

Obesity / overweight, Type 1 diabetes

Eligibility highlights

•BMI ≥25

Primary endpoints

•Time of Cmax (Tmax) of Acetaminophen•PK: Area Under the Concentration Versus Time Curve from Time Zero to Time t•PK: Maximum Observed Drug Concentration (Cmax) of Acetaminophen

Registered trial locations

Locations reported to ClinicalTrials.gov for this trial snapshot. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

NCT IDNCT07803744

Org study ID27861

Secondary IDI8F-MC-GPJIEli Lilly and Company

Timeline

Milestones

Study first posted2026-09-04actual

Study start2026-09-11actual

Last update posted2026-09-23actual

Primary completion2026-12estimated (month precision)

Study completion2026-12estimated (month precision)

Assets

Investigational agents

Tirzepatide

Who this study enrolls

Obesity / overweightType 1 diabetes

Who can enroll

Minimum age18 Years

Maximum age70 Years

SexAll

Healthy volunteersNot accepted

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

Endpoints (7)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Safety / tolerability / PK

7 endpoints

Primary/protocol endpoint

Pharmacokinetics (PK): Time of Maximum Observed Drug Concentration (Tmax) of Acetaminophen

Time frame:Predose on Day 1 through 36 hours post dose

concentration, descriptive

Primary/protocol endpoint

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

concentration, descriptive

Primary/protocol endpoint

PK: Maximum Observed Drug Concentration (Cmax) of Acetaminophen

Time frame:Predose on Day 1 through 36 hours post dose

concentration, descriptive

Secondary/protocol endpoint

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

concentration, descriptive

Secondary/protocol endpoint

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

concentration, descriptive

Secondary/protocol endpoint

PK: Maximum Observed Drug Concentration (Cmax) of Tirzepatide

Time frame:Predose on Day 1 through Day 29

concentration, descriptive

Secondary/protocol endpoint

PK: Time of Maximum Observed Drug Concentration (Tmax) of Tirzepatide

Time frame:Predose on Day 1 through Day 29

concentration, descriptive

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateNovember 5, 2026

Endpoint classificationDelfa endpoint taxonomy v2 (May 13, 2026)

Results tableno registry results posted yet

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the November 5, 2026 snapshot.