Model-based simulation of glycaemic effect and body weight loss when switching from semaglutide or dulaglutide to once weekly tirzepatide.

Objective: To evaluate the efficacy endpoints of HbA1c and body weight loss after switching from the GLP-1 receptor agonists, semaglutide or dulaglutide, to treatment with the GIP/GLP-1 receptor agonist (RA) tirzepatide.

Methods: Models were developed and validated to describe the HbA1c and weight loss time course for semaglutide (SUSTAIN 1-10), dulaglutide (AWARD-11) and tirzepatide (SURPASS 1-5, phase 3 global T2D program). The impact of switching from once weekly GLP-1 RAs to tirzepatide was described by simulating the efficacy time course. Semaglutide and dulaglutide doses were escalated in accordance with their respective labels.

Results: Model-predicted mean decreases from baseline in HbA1c and body weight for semaglutide 0.5 mg, 1 mg, and 2 mg were 1.22 to 1.79% and 3.62 to 6.87 kg respectively, at Week 26. Model-predicted mean decreases from baseline in HbA1c and body weight for dulaglutide 1.5 mg, 3 mg and 4.5 mg were 1.53 to 1.84% and 2.55 to 3.71 kg respectively, at Week 26. After switching to tirzepatide 5, 10 and 15 mg HbA1c reductions were predicted to range between 1.95 to 2.46% and body weight reductions between 6.50 to 12.1 kg by Week 66.

Conclusion: In this model-based simulation, switching from approved maintenance doses of semaglutide or dulaglutide to tirzepatide, even at the lowest approved maintenance dose of 5 mg, showed the potential to further improve HbA1c and body weight reductions.