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Acute Metabolic Effects of Tirzepatide in Type 1 Diabetes

This study will examine the effects of Tirzepatide (TZP), a glucagon-like peptide 1 (GLP1) - gastric inhibitory peptide (GIP) co-agonist, on metabolism in type 1 diabetes (T1D). Research participants with T1D will undergo measures of insulin sensitivity, and hormone levels post-meal, post-hypoglycemia and during the overnight period. These measures will be performed prior to, and after 6 weeks of treatment with TZP or placebo.

ClinicalTrials.gov IDNCT06820281

PhasePHASE2

Enrollment44

SponsorVictor Chang Cardiac Research Institute

Age18 Years – 70 Years

SexALL

I'm interested View official listing

Conditions studied

Type 1 Diabetes Mellitus

About this study

Interventions

Drug: Tirzepatide 2.5mg weekly — Tirzepatide 2.5 mg/0.5 mL solution for injection vial or pre-filled pen. Each vial/ pre-filled pen contains tirzepatide 2.5 mg in 0.5 mL solution (2.5mg in 0.6mL if Kwikpen) Tirzepatide will be administered by drawing up into a syringe, then administering by subcutaneous injection weekly by study nurses.
Drug: Placebo injection (normal saline) — Placebo will be given as 0.5mL normal saline (if comparator against vial or pre-filled pen), or 0.6mL (if comparator against Mounjaro Kwikpen), drawn up into a syringe and administered by subcutaneous injection weekly by study nurses.

Primary outcomes

Whole-body insulin sensitivity (6 weeks)

Eligibility information

Inclusion Criteria: * age 18-70 years * BMI ≥ 25 kg/m2 * HbA1c ≤ 9.0% * insulin delivery using an automated insulin delivery system * at least 2 years since diagnosis of type 1 diabetes Exclusion Criteria: * TZP or GLP-1 receptor agonist in last 3 months; metformin or sodium glucose co-transporter 2 (SGLT2) inhibitor in the last 6 weeks; systemic steroids, antipsychotics, in the last 6 weeks. * Hypoglycemic unawareness or severe hypoglycemia last 6 months. * History of seizure disorder. * History of weight loss surgery. * eGFR \<60 mL/min/1.73 m2. * Liver disease (known cirrhosis, LFTs \> 3x upper limit of normal). * Active malignancy. * Pregnant, breastfeeding, planning pregnancy within 6 months, or not using adequate contraception. * Coronary event or stroke in last 6 months * Active or untreated proliferative diabetic retinopathy * Hemoglobin level \< 13.5 g/dL in men, \< 12.0 g/dL in women

Study locations

Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010 Australia

Before you participate: Varda Clinical is an independent discovery tool, not the study sponsor or a medical provider. Eligibility can only be determined by the official study team. Discuss potential risks and benefits with a qualified healthcare professional.

Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-10-21.