For people with type 2 diabetes who are already on tirzepatide but still have an A1c above 7%, adding or switching to the long‑acting insulin glargine 300 (Gla‑300) can drop A1c by about 1.3% over six months, with roughly one‑quarter of users hitting the <7% target and no reported low‑blood‑sugar events.

Tirzepatide is recommended as a first-line injectable for people with type 2 diabetes (T2D), but there is a paucity of data on the use of basal insulin after tirzepatide in this population. This study aimed to evaluate glycemic control in people with T2D newly intensified with insulin glargine 300 U/ml (Gla-300) who had suboptimal HbA1c after treatment with tirzepatide. DELIVER-T was a retrospective analysis of the US Optum's Clinformatics^&#xae; Data Mart from January 1, 2022 to August 31, 2024. People with T2D were included if they were insulin na&#xef;ve and were previously treated with tirzepatide and then intensified with Gla-300. The primary analysis (Gla-300 switch/add-on group) included all those with a HbA1c&#x2009;&gt;&#x2009;7.0% at baseline who either switched from tirzepatide to Gla-300 or who added Gla-300 to tirzepatide. The primary endpoint was the change in HbA1c levels from baseline to 6&#xa0;months. Secondary endpoints included reaching HbA1c target &lt; 7.0% and any hypoglycemia. In total, 82 people had a HbA1c&#x2009;&gt;&#x2009;7.0% at baseline and were included in the primary analysis (Gla-300 switch/add-on group). The mean (SD) change in HbA1c from baseline to 6&#xa0;months was -&#xa0;1.3% (2.0; p&#x2009;=&#x2009;0.0027) for the primary analysis (Gla-300 switch/add-on group). The proportion of participants reaching the target of HbA1c&#x2009;&lt;&#x2009;7.0% at 6&#xa0;months was 26.8% (n&#x2009;=&#x2009;22) for the primary analysis (Gla-300 switch/add-on group). No hypoglycemic events were captured in the database during the 6-month follow-up period. In insulin-na&#xef;ve people with T2D who had suboptimal HbA1c with tirzepatide, significant reductions in HbA1c and improvements in the percentage of people reaching HbA1c target of &lt; 7.0% were observed with Gla-300. Infographic and video abstract available for this article. Please follow the digital features link under the abstract. A video abstract of the Deliver-T study, which evaluated glycaemic control in people with T2D previously treated with tirzepatide and newly intensified with insulin glargine 300 U/mL (Gla-300).