Garvan Institute of Medical Research
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 4 weeks of treatment with TZP. These measures will also be compared to a group of adults without diabetes (who will not receive treatment with TZP) to assess how metabolism of energy and nutrients is different in T1D compared to people without diabetes.
Type 1 Diabetes Mellitus
Tirzepatide 2.5mg weekly
Placebo injection (normal saline)
PHASE2
TIRTLE2 is a phase 2 double-blinded placebo-controlled mechanistic clinical trial that extends upon the findings of TIRTLE1, a phase 2 double-blinded placebo-controlled trial (TZP 5.0mg vs placebo over 12 weeks) in T1D (trial registration: ACTRN12624000111572). TIRTLE2 is a designed to 1) demonstrate that T1D is associated with insulin resistance, increased lipolysis and excessive growth hormone and prandial glucagon secretion; 2) determine whether TZP can improve whole body insulin sensitivity (main aim) and adipose insulin sensitivity, while reducing growth homrone and prandial glucagon secretion, before significant weight loss (indicating a role for TZP beyond weight management in T1D); 3) determine if TZP can maintain the glucagon response to hypoglycemia. To address these research aims, a single comprehensive clinical trial will be performed in 20 participants with T1D, who will receive a weekly injection of TZP 2.5mg or placebo for 4 weeks. A short treatment duration was chosen to assess if TZP offers T1D-specific benefits prior to significant weight loss. Dynamic tests will also be performed in 10 participants without diabetes in a baseline only cross-sectional study (participants without diabetes will not receive treatment in the main clinical trial). TIRTLE2 will employ the 'gold standard' hyperinsulinemic-euglycemic and hypoglycemic clamps, in conjunction with complementary analyses of the effects of TZP on metabolism across multiple physiological states. This mechanistic study will define mechanisms by which GLP1-GIP co-agonism may uniquely provide clinical benefits in T1D during the fasting and fed states, and during hypoglycemia.
| Study Type : | INTERVENTIONAL |
| Estimated Enrollment : | 20 participants |
| Masking : | QUADRUPLE |
| Primary Purpose : | TREATMENT |
| Official Title : | Acute Metabolic Effects of Tirzepatide in Type 1 Diabetes: a Phase 2 Double Blinded Placebo Controlled Clinical Trial (TIRTLE2) |
| Actual Study Start Date : | 2025-12-01 |
| Estimated Primary Completion Date : | 2027-12-31 |
| Estimated Study Completion Date : | 2027-12-31 |
Information not available for Arms and Intervention/treatment
| Ages Eligible for Study: | 18 Years to 55 Years |
| Sexes Eligible for Study: | ALL |
| Accepts Healthy Volunteers: | 1 |
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Not yet recruiting
Garvan Institute of Medical Research
Sydney, New South Wales, Australia, 2010