Switching to Tirzepatide better than Increasing Dulaglutide Dose in poorly controlled Type 2 Diabetes: Study
Researchers have found in a new research that among patients with poorly controlled type 2 diabetes, switching from dulaglutide to tirzepatide resulted in significantly better outcomes than increasing the dulaglutide dose. The randomized trial showed greater reductions in HbA1c (1.44% vs 0.67%) and body weight (23.1 lbs vs 7.9 lbs) with tirzepatide, highlighting its superior efficacy in glycemic control and weight management. The study was published in the journal Annals of Internal Medicine by Liana K. B. and colleagues.
The SURPASS-SWITCH trial, a multicenter, randomized, open-label, phase 4 study, evaluated the efficacy and safety of escalating dulaglutide doses versus switching to tirzepatide. Conducted across 38 sites in five countries, the trial included 282 adults with hemoglobin A1c (HbA1c) levels between 7.0% and 9.5%, a stable body mass index of 25 kg/m² or greater, and a consistent dulaglutide regimen of at least 0.75 mg for six months.​
Tirzepatide is a once-weekly glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide receptor agonist indicated for the treatment of adults with type 2 diabetes or obesity. The SURPASS-SWITCH trial compared the outcomes of escalating doses of dulaglutide vs switching to tirzepatide in patients with type 2 diabetes who were still not adequately controlled.
In this phase 4 trial, patients were randomly assigned to either increase their dulaglutide dose to 4.5 mg or the maximum tolerated dose (MTD) or transition to tirzepatide. The primary endpoint was the change in HbA1c from baseline at week 40, and the key secondary endpoint was the change in body weight from baseline at the same time.​
Key Findings
• At week 40, the tirzepatide switch group had a mean HbA1c decrease of 1.44% (SE, 0.07), vs a 0.67% (SE, 0.08) decrease in the dulaglutide step-up group.
• The treatment difference estimate was -0.77% (95% CI, -0.98% to -0.56%; p< 0.001). With regards to weight loss, the group treated with tirzepatide lost 10.5 kg (SE, 0.5) compared to the dulaglutide group, which lost 3.6 kg (SE, 0.5), with an estimated treatment difference of -6.9 kg (95% CI, -8.3 to -5.5 kg; p< 0.001).​
• Severe adverse events were experienced by 10 patients in the tirzepatide arm (7.2%) and 10 patients in the dulaglutide arm (7.0%).
• The most frequent treatment-emergent adverse events were diarrhea and nausea, as would be expected based on prior experience with these drugs.​
The SURPASS-SWITCH trial proved that switching from dulaglutide to tirzepatide is associated with extra HbA1c and body weight reductions over increasing dulaglutide doses. This implies that tirzepatide could be a superior treatment in adults with type 2 diabetes not adequately controlled on dulaglutide.
Reference:
Billings LK, Winne L, Sharma P, et al. Comparison of Dose Escalation Versus Switching to Tirzepatide Among People With Type 2 Diabetes Inadequately Controlled on Lower Doses of Dulaglutide: A Randomized Clinical Trial. Presented at: ACP IM Meeting 2025; April 3-5; New Orleans, Louisiana.
