A Long-Term Study of Tirzepatide (LY3298176) in Adults With Type 1 Diabetes and Obesity or Overweight (SURPASS-T1D-2)

February 13, 2026 updated by: Eli Lilly and Company

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study Evaluating the Efficacy and Long-Term Safety of Tirzepatide Once Weekly Compared to Placebo in Adults With Type 1 Diabetes and Obesity or Overweight

The main purpose of this study is to find out how well and how safely tirzepatide works long-term in adults who have type 1 diabetes and obesity or overweight. Participation in the study will last about 20 months.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

465

Phase

  • Phase 3

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

  • Argentina
      • Buenos Aires, Argentina, 1061
        • Buenos Aires Macula S.A
      • Buenos Aires, Argentina, C1023AAB
        • Stat Research S.A.
      • Buenos Aires, Argentina, C1128AAF
        • Mautalen Salud e Investigación
      • Córdoba, Argentina, 5000
        • Centro Diabetológico Dr. Waitman
      • Godoy Cruz, Argentina, M5501ARP
        • CIPADI - Centro Integral de Prevencion y Atencion en Diabetes
      • Granadero Baigorria, Argentina, 2152
        • Centro de Investigaciones Clínicas Baigorria
      • Rosario, Argentina, 2000
        • Instituto Médico Catamarca IMEC
      • San Miguel de Tucumán, Argentina, T4000ICL
        • Investigaciones Clínicas Tucumán
  • Brazil
      • Brasília, Brazil, 71625-175
        • Centro de Pesquisa Clinica do Brasil
      • Campinas, Brazil, 13060-803
        • Centro de Pesquisa Sao Lucas
      • Curitiba, Brazil, 80045170
        • Quanta Diagnóstico e Terapia
      • Goiânia, Brazil, 74230-035
        • Cendi - Endocrinologia e Diabetes
      • Porto Alegre, Brazil, 91350-250
        • Instituto da Crianca com Diabetes
      • Rio de Janeiro, Brazil, 20241-180
        • IBPClin - Instituto Brasil de Pesquisa Clínica
      • São Paulo, Brazil, 04266-010
        • CEPIC - Centro Paulista de Investigação Clínica
      • São Paulo, Brazil, 01228-200
        • CPCLIN
  • Canada
      • Montreal, Canada, H4J 1E3
        • Endocrinologie Oasis
      • Ottawa, Canada, K2J 0V2
        • Centricity Research Ottawa LMC Endocrinology
      • Sherbrooke, Canada, J1G 1X9
        • Centre de Recherche Saint-Louis
      • Surrey, Canada, V3T 2V6
        • TLC Diabetes and Endocrinology
      • Sydney, Canada, B1M 0A1
        • Care Access - Cape Breton
  • Czechia
      • Chrudim III, Czechia, 537 01
        • INTENDIA klinika s.r.o.
      • Hranice, Czechia, 753 01
        • AIDIN VK s.r.o.
      • Krnov, Czechia, 79401
        • MUDr. Tomas Edelsberger
      • Olomouc, Czechia, 779 00
        • Diabetologické centrum s.r.o.
      • Prague, Czechia, 14900
        • Milan Kvapil s.r.o., Diabetologicka ambulance
      • Prague, Czechia, 18100
        • ResTrial s.r.o.
  • France
      • Bois-Guillaume, France, 76230
        • Centre Hospitalier Universitaire - Hôpitaux de Rouen - Hôpital de Bois-Guillaume
      • Corbeil-Essonnes, France, 91106
        • Centre Hospitalier Sud Francilien
      • Grenoble, France, 38700
        • Centre Hospitalier Universitaire de Grenoble
      • Le Creusot, France, 71200
        • Hôtel-Dieu du Creusot - site Harfleur
      • Marseille, France, 13005
        • Hôpital de la Conception
      • Paris, France, 75010
        • Assistance Publique Hôpitaux de Paris - Groupe Hospitalier 10e - Hôpital Lariboisière
      • Toulouse, France, 31059
        • CHU Rangueil
      • Vénissieux, France, 69200
        • Groupe Hospitalier Mutualiste Les Portes du Sud
  • Greece
      • Athens, Greece, 151 25
        • Athens Medical Center
      • Palaió Fáliro, Greece, 17562
        • Iatriko Paleou Falirou Medical Center
      • Thessaloniki, Greece, 546 45
        • Euromedica General Clinic of Thessaloniki
      • Thessaloniki, Greece, 54642
        • Ippokrateio General Hospital of Thessaloniki
  • Mexico
      • Chihuahua City, Mexico, 31110
        • Enclifar Ensayos Clínicos Farmacológicos Sc
      • Guadalajara, Mexico, 44670
        • Private Practice - Dr. Arechavaleta Granell Maria del Rosario
      • Guadalajara, Mexico, 44670
        • Unidad de Investigación Clínica y Atención Médica HEPA S.C.
      • Guadalajara, Mexico, 44150
        • Unidad de Investigaci�n Cl�nica Cardiometabolica de Occidente
      • Mexico City, Mexico, 14080
        • Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
      • Monterrey, Mexico, 64020
        • CEINV Salud
      • Monterrey, Mexico, 64610
        • Clínica García Flores SC
      • Puebla City, Mexico, 72190
        • Consultorio Médico de Endocrinología y Pediatría
      • Tampico, Mexico, 89210
        • Medsal Centro Médico
  • Romania
      • Baia Mare, Romania, 430222
        • CMI DNBM Dr. Pop Lavinia
      • Brasov, Romania, 500097
        • Mariodiab Clinic
      • Bucharest, Romania, 050913
        • Diabet Med
      • Bucharest, Romania, 020359
        • Centrul medical DiabNutriMed
      • Bucharest, Romania, 060013
        • Sanamed Hospital
      • Galați, Romania, 800291
        • Diamed Obesity
      • Iași, Romania, 700547
        • Centrul Medical Consultmed
      • Târgovişte, Romania, 130168
        • Rinart Diab SRL
  • Spain
      • Badajoz, Spain, 06080
        • Hospital Infanta Cristina
      • Badalona, Spain, 08916
        • Hospital Germans Trias i Pujol
      • Barcelona, Spain, 08036
        • Hospital Clinic De Barcelona
      • Madrid, Spain, 28034
        • Hospital Universitario Ramon y Cajal
      • Seville, Spain, 41013
        • Hospital Universitario Virgen del Rocio
  • United States
    • California
      • Bonita, California, United States, 91902
        • Kaiser Permanente Bonita Medical Offices
      • Escondido, California, United States, 92025
        • AMCR Institute
      • Newport Beach, California, United States, 92663
        • Mary & Dick Allen Diabetes Center
      • Tustin, California, United States, 92780
        • University Clinical Investigators, Inc.
    • Colorado
      • Aurora, Colorado, United States, 80045
        • University of Colorado Anschutz Medical Campus
    • Florida
      • West Palm Beach, Florida, United States, 33401
        • Metabolic Research Institute, Inc.
    • Iowa
      • West Des Moines, Iowa, United States, 50266
        • Iowa Diabetes and Endocrinology Research Center
    • Minnesota
      • Minneapolis, Minnesota, United States, 55416
        • HealthPartners Institute dba International Diabetes Center
    • Missouri
      • Chesterfield, Missouri, United States, 63005
        • Clinical Research Professionals
      • Springfield, Missouri, United States, 65807
        • Clinvest Headlands Llc
    • Nevada
      • Henderson, Nevada, United States, 89074
        • Las Vegas Endocrinology
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • University of North Carolina Medical Center
    • Texas
      • Dallas, Texas, United States, 75230
        • Velocity Clinical Research, Dallas
      • Houston, Texas, United States, 77040
        • Juno Research
      • Mesquite, Texas, United States, 75149
        • Southern Endocrinology Associates
      • Round Rock, Texas, United States, 78681
        • Texas Diabetes & Endocrinology, P.A.
      • San Antonio, Texas, United States, 78240
        • San Antonio Clinical Trials
      • Weslaco, Texas, United States, 78596
        • Texas Valley Clinical Research

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 type 1 diabetes and on insulin treatment for at least one year prior to screening
  • Have an HbA1c value of 7.0% to 10.5% inclusive, at screening
  • Have a body mass index (BMI) of ≥25 kilograms per square meter (kg/m2) at screening
  • Are of stable weight for at least 90 days prior to screening and agree to not start an intensive diet or exercise program during the study

Exclusion Criteria:

  • Have experienced two or more events requiring hospitalization due to poor glucose control (hyperglycemia or (diabetic ketoacidosis (DKA)) during the period of 180 days prior to screening and until randomization.
  • Have experienced one or more events of severe hypoglycemia during the period of 90 days prior to screening and until randomization.
  • Are currently receiving or planning to receive treatment for diabetic retinopathy and/or macular edema
  • Have had chronic or acute pancreatitis
  • Have used any weight loss drugs or alternative remedies, including herbal or nutritional supplements, within 90 days prior to screening

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tirzepatide
Participants will receive tirzepatide subcutaneously (SC)
Drug: Tirzepatide
Administered SC
Other Names:
  • LY3298176
Placebo Comparator: Placebo
Participants will receive placebo SC
Drug: Placebo
Administered SC

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in Hemoglobin A1c (HbA1c)
Time Frame: Baseline, Week 40
Baseline, Week 40

Secondary Outcome Measures

Outcome Measure
Time Frame
Change from Baseline in HbA1c
Time Frame: Baseline, Week 72
Baseline, Week 72
Percentage of Time Continuous Glucose Monitor (CGM) Glucose Values are Between 70 and 180 milligrams per deciliter (mg/dL) (3.9 and 10.0 millimoles per liter (mmol/L)) Inclusive, Per Day
Time Frame: Within 30 days prior to Week 40, Within 30 days prior to Week 72
Within 30 days prior to Week 40, Within 30 days prior to Week 72
Change from Baseline in Body Weight
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percent Change from Baseline in Body Weight
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percentage of Participants with ≥5% Body Weight Reduction
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percentage of Participants with ≥10% Body Weight Reduction
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percentage of Participants with ≥15% Body Weight Reduction
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Change from Baseline in Waist Circumference
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Change from Baseline in Systolic Blood Pressure (SBP)
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percent Change from Baseline in Fasting Triglycerides
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percent Change from Baseline in Fasting Non-High-Density Lipoprotein (non-HDL) Cholesterol
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percent Change from Baseline in Total Daily Insulin Dose
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Percent Change from Baseline in High-Sensitivity C-Reactive Protein (hsCRP)
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72
Change from Baseline in EQ-5D-5L
Time Frame: Baseline, Week 40, Week 72
Baseline, Week 40, Week 72

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

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.

Helpful Links

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)

May 12, 2025

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

May 6, 2025

First Submitted That Met QC Criteria

May 6, 2025

First Posted (Actual)

May 8, 2025

Study Record Updates

Last Update Posted (Actual)

February 17, 2026

Last Update Submitted That Met QC Criteria

February 13, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 27340
  • 2024-519685-51-00 (Ctis)
  • I8F-MC-GPJD (Other Identifier: Eli Lilly and Company)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

IPD Sharing Time Frame

Data are available 6 months after the primary publication and approval of the indication studied in the US and EU, whichever is later. Data will be indefinitely available for requesting.

IPD Sharing Access Criteria

A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • CSR

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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