Switching to tirzepatide improves outcomes vs. escalating dulaglutide in type 2 diabetes
An industry-funded randomized trial found that switching to tirzepatide after inadequate response to dulaglutide led to significant additional reductions in HbA1c levels and weight at 40 weeks compared with increasing the dulaglutide dose.
Switching patients with type 2 diabetes to tirzepatide after inadequate response to dulaglutide was associated with better HbA1c control and additional weight loss versus increasing the dulaglutide dose, a recent industry-funded study found.
Researchers performed a multicenter open-label randomized trial to compare the efficacy and safety of escalating dulaglutide versus switching to tirzepatide in patients with inadequately controlled type 2 diabetes. The SURPASS-SWITCH trial included adults who had an HbA1c level from 7.0% to 9.5%, stable body weight, and a body mass index of at least 25 kg/m2 who were on a stable dose of dulaglutide (0.75 or 1.5 mg) for at least six months. Patients were randomized to either switch to tirzepatide, 2.5 mg, escalating to 15 mg (or the maximum tolerated dose) or to escalate dulaglutide to 4.5 mg (or the maximum tolerated dose). The study's primary and key secondary end points were changes in HbA1c level and weight from baseline at week 40. The results of the study, which was funded by Eli Lilly and Company, were published April 4 by Annals of Internal Medicine.
Overall, 139 adults were assigned to tirzepatide and 143 were assigned to dulaglutide. Mean diabetes duration was 11.2 years, mean HbA1c level was 7.82%, and mean weight was 96.9 kg. Change from baseline in HbA1c level at week 40 was −1.44% with 15 mg or the maximum tolerated dose of tirzepatide and −0.67% with 4.5 mg or the maximum tolerated dose of dulaglutide (estimated treatment difference, −0.77% [95% CI, −0.98% to −0.56%]; P<0.001). For weight, the change from baseline at week 40 was −10.5 kg with tirzepatide and −3.6 kg with dulaglutide (estimated treatment difference, −6.9 kg [95% CI, −8.3 to −5.5 kg]; P<0.001). Ten patients in each group (7.2% and 7.0%, respectively) reported serious adverse events, with nausea and diarrhea the most common adverse events related to study treatment.
Limitations of the study include its open-label design and the fact that it evaluated switches only from dulaglutide, the authors noted. They concluded that switching treatment to tirzepatide in patients with type 2 diabetes inadequately controlled on dulaglutide provided additional HbA1c reduction and weight loss versus escalating dulaglutide treatment. “Further research is needed to assess the potential benefit of early glycemic control via early medication switching on longer-term clinical outcomes,” they wrote.