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Taking people in CanadaPhase 2/3

Tests tirzepatide in adults with type 1 diabetes who use an insulin pump

Tests whether tirzepatide lets adults with type 1 diabetes skip counting carbohydrates at meals.

Key facts

Who runs it
McGill University Health Centre/Research Institute of the McGill University Health Centre
Where
Montreal, CanadaSee the 3 sitesAlso in 1 other country, 1 site
Trial code
Registry title
A Clinical Trial Using Tirzepatide to Help Adults With Type 1 Diabetes Automatically Control Their Blood Sugar
Status
Recruiting
Phase
Phase 2/3
People taking part
105 people, planned
Started
19 May 2026
Expected to end
Jan 2029
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Tirzepatide
  • Tandem Control-IQ Automated Insulin Delivery System (with Dexcom G7 CGM)
  • Carbohydrate Counting
  • No Meal Announcement
Record updated
27 May 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with type 1 diabetes who count carbohydrates and have a higher body weight. It tests whether tirzepatide helps control blood sugar without counting carbs.

Age
18 years or older
Sex
All sexes
Disease stage
Type 1 diabetes for at least 1 year, with HbA1c above 6.5% (48 mmol/mol) and below 12% (108 mmol/mol), and a BMI of 27 kg/m2 or more
Earlier treatment
Must be on multiple daily insulin injections or an insulin pump, and actively count carbohydrates for mealtime insulin. Must not have used GLP1-RAs in the last four weeks.

Main reasons for not taking part

  • Pregnant, planning pregnancy, or breastfeeding
  • History of pancreatitis
  • Personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2
  • Severe low blood sugar needing hospital care, or diabetic ketoacidosis, in the last 2 months
  • Severe kidney problems (eGFR below 30 mL/min/1.73 m2)

The registry criteria, word for word

Show all 23 criteriaShow less

Who can take part

  • Age ≥ 18 years
  • Clinical diagnosis of type 1 diabetes for ≥ 1 year, per investigator judgment (confirmatory C-peptide and autoantibodies not required)
  • A BMI ≥ 27 kg/m2
  • HbA1c > 6.5%, and < 12%
  • Current therapy: multiple daily injections or insulin pump
  • Willingness to use Tandem Control IQ insulin pump system with the use of rapid or ultra rapid-acting insulins compatible with Tandem Control-IQ pump (e.g. Fiasp is not compatible)
  • Active carbohydrate counting for prandial insulin dosing
  • Individuals of childbearing potential must be using or agree to use an effective birth-control method. Childbearing potential refers to participants of the female sex post-menarche who have not reached menopause and who do not have a medical condition causing sterility (e.g., hysterectomy). Post-menopausal state refers to the absence of menses for 12 months without any alternative cause

Who cannot take part

  • History of acute or chronic pancreatitis
  • Personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2
  • History of bariatric surgery within the last 6 months
  • Medical or psychiatric illness likely to interfere with participation (e.g. cirrhosis, active cancer, decompensated schizophrenia), per investigator judgment
  • Inability or unwillingness to comply with safe diabetes management practices, in the view of the investigator
  • Severe renal impairment with eGFR <30 mL/min/1.73 m2 (CKD-EPI), measured within the last four months
  • Use of GLP1-RAs within the last four weeks
  • Use of antihyperglycemic agents other than insulin or metformin within the last 2 weeks
  • Planned or ongoing pregnancy
  • Breastfeeding
  • Severe hypoglycemia requiring hospitalization in the past 2 months. Severe hypoglycemia is defined as requiring the assistance of another person, due to altered consciousness, to administer carbohydrates, glucagon, or other resuscitative actions
  • Diabetic ketoacidosis within the last 2 months
  • Clinically significant proliferative diabetic retinopathy or gastroparesis, as per the judgment of the investigator
  • Current or ≤ 1 month use of supraphysiological doses of oral or intravenous glucocorticoids
  • Any safety concern that, in the investigator's judgment, precludes participation

Where in Canada

Also in 1 other country, 1 site

  • Hygea Medical ClinicMontreal, CanadaContact: Keddy Moise, MSc (candidate)Taking people
  • Institut de Recherches Cliniques de MontrealMontreal, CanadaContact: Rémi Rabasa-Lhoret, MD-PhDNot yet recruiting
  • McGill University Health CentreMontreal, CanadaContact: Keddy Moise, MSc (candidate)Not yet recruiting

About the trial

What the trial wants to find out

This research study is testing whether a weekly medication called tirzepatide can help adults with type 1 diabetes use their insulin pump more easily, specifically by reducing or eliminating the need to count carbohydrates at meals.

Read full original descriptionShow less

People with type 1 diabetes must take insulin for life, and even with advanced insulin pumps and continuous glucose monitors, many still struggle to keep blood sugar within the target range. One of the biggest challenges is carbohydrate counting, which requires estimating the amount of carbohydrates in every meal to give the correct insulin dose.

Tirzepatide is a medication currently approved for type 2 diabetes and weight management. Early research suggests it may also help people with type 1 diabetes by lowering appetite, slowing digestion, reducing insulin needs, and smoothing after-meal blood sugar rises.

This study will include 105 adults with type 1 diabetes at centers in Canada and Switzerland. Everyone will use the Tandem Control-IQ insulin pump with a Dexcom G7 continuous glucose monitor. Participants are randomly assigned to one of two groups:

Tirzepatide group:

Participants receive weekly tirzepatide injections. After the dose is gradually increased over 12 weeks, they will eventually try using their insulin pump without entering carbohydrate amounts at meals.

Control group:

Participants continue their usual therapy and keep counting carbohydrates for their mealtime insulin doses.

The main goal of the study is to learn whether people taking tirzepatide can safely maintain good blood sugar control without counting carbs, compared with standard care. All participants will attend several clinic visits and share their glucose, insulin, and health data throughout the 32-week trial. Some centers will also conduct heart/fitness, or body-composition tests.

As with any medication, tirzepatide may cause side effects such as nausea, vomiting, diarrhea, or decreased appetite. Rare but serious risks like gallbladder disease or pancreatitis are also monitored. Pregnancy must be avoided during the trial.

Overall, this study aims to understand whether adding tirzepatide to automated insulin delivery can simplify diabetes management, reduce burden, and maintain safe and effective glucose control for adults living with type 1 diabetes.

The 2 groups in the trial

  • Tirzepatide groupTreatment being tested

    Participants randomized to this arm receive once-weekly subcutaneous tirzepatide in addition to use of the Tandem Control-IQ insulin pump and Dexcom G7 continuous glucose monitor. Tirzepatide is initiated at 2.5 mg weekly and increased by 2.5 mg every 4 weeks to a target dose of 10 mg weekly or the maximally tolerated dose. Dose escalation may be delayed or reduced if participants experience intolerable gastrointestinal symptoms. During Weeks 1-26, participants continue standard carbohydrate counting for all meals. Beginning in Week 27, participants stop entering carbohydrate amounts into the pump (no meal announcements) for six weeks while continuing tirzepatide at their maintenance dose. Throughout the intervention, participants undergo regular safety assessments, remote glucose data reviews, insulin-pump parameter adjustments as needed, and scheduled in-person visits to monitor metabolic, cardiovascular, and patient-reported outcomes.

    Treatment: Tirzepatide, Tandem Control-IQ Automated Insulin Delivery System (with Dexcom G7 CGM), Carbohydrate Counting, and No Meal Announcement

  • Control groupExisting treatment, for comparison

    Participants randomized to the control arm use the Tandem Control-IQ automated insulin delivery system with the Dexcom G7 continuous glucose monitor, following standard-of-care diabetes management. They continue carbohydrate counting for all meals throughout the 32-week study and deliver prandial insulin boluses based on estimated carbohydrate intake, as is typical for users of hybrid closed-loop systems. No tirzepatide injections are administered. Participants receive the same device training, follow-up schedule, safety monitoring, glucose data reviews, and pump parameter adjustments as the tirzepatide arm. This arm serves as an active comparator, representing current standard therapy for type 1 diabetes with automated insulin delivery and meal announcements.

    Treatment: Tandem Control-IQ Automated Insulin Delivery System (with Dexcom G7 CGM) and Carbohydrate Counting

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Fully Closed-Loop Glucose Control in Adults With Type 1 Diabetes Using Tirzepatide: a Randomized, Multi-center, Open-label, Non-inferiority, Parallel Trial
Plain-language title
Tests tirzepatide in adults with type 1 diabetes who use an insulin pumpGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Record updated
27 May 2026