Tirzepatide in type 2 diabetes mellitus: durability of effect
In the population defined for type 2 diabetes mellitus, is the effect of Tirzepatide maintained across the full duration of the contributing trials?
Templated review frame. This review question was generated by crossing an indication with a compound for which contributing trials exist. Its prose frame is templated and is shared with other questions of the same shape. Its included studies, its summary of findings and its certainty rating are computed from the underlying records and are not templated. The Institute publishes these questions because the alternative is to leave a question the document set can answer unanswered, and it labels them because the alternative is to present a templated frame as an authored one.
§1Abstract
§1.1Review question
In the population defined for type 2 diabetes mellitus, is the effect of Tirzepatide maintained across the full duration of the contributing trials?
§1.2PICO frame
Table 1. The registered PICO frame. Any change made after protocol registration is recorded in the amendment log at §5 and is identified there as post hoc.
| Element | As registered |
|---|---|
| Population | A disorder of glucose regulation characterised by insulin resistance with relative insulin deficiency, diagnosed by glycated haemoglobin, fasting plasma glucose or oral glucose tolerance criteria. |
| Intervention | Tirzepatide administered as subcutaneous once weekly. |
| Comparator | The comparator used in each contributing trial, reported per trial rather than pooled across comparator types. |
| Outcomes | Anchor outcome for this indication: Change in HbA1c (%, mmol/mol). Additional outcomes: Proportion achieving HbA1c <7.0 % and ≤6.5 %; Change in fasting serum glucose; Change in body weight. |
§1.3Method in brief
A review of the effects of an intervention on pre-specified outcomes, with a quantitative synthesis where the contributing studies are sufficiently similar. The protocol was registered with the Institute's secretariat before the search was executed. The search was run on 6 July 2025 across 8 sources and is reproduced in full at §2. Screening, extraction and certainty assessment were performed independently by two members of the secretariat with disagreement resolved by a third.[1,2]
§1.4Conclusion
High certainty evidence bears on whether the effect of Tirzepatide in type 2 diabetes mellitus is maintained across the randomised period. The contributing trials range in duration and the Institute reports the trajectory per trial rather than pooling across durations, because a mean at 36 weeks and a mean at 104 weeks are not estimates of the same quantity.
The conclusion rests on 7 contributing studies, listed with their extracted data at §3 and summarised outcome by outcome at §4.
§1.5Limitations
References cited on this page
References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.
- Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine 2022;387(3):205–216. doi:10.1056/NEJMoa2206038 · PMID 35658024
- Garvey WT, Frias JP, Jastreboff AM, le Roux CW, Sattar N, Aizenberg D, Mao H, Zhang S, Ahmad NN, Bunck MC, Benabbad I, Zhang XM. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial. The Lancet 2023;402(10402):613–626. doi:10.1016/S0140-6736(23)01200-X · PMID 37385275
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