HAMBURG, GERMANY – Once-weekly tirzepatide (Mounjaro, Lilly) added to insulin glargine resulted in greater reductions in hemoglobin A1c along with more weight loss and less hypoglycemia, compared with prandial insulin lispro (Humalog, Sanofi), for patients with inadequately controlled type 2 diabetes, show data from the SURPASS-6 randomized clinical trial.
It also resulted in a higher percentage of participants meeting an A1c target of less than 7.0%, wrote the researchers, whose study was presented at the annual meeting of the European Association for the Study of Diabetes and was published simultaneously in JAMA.
Also, daily insulin glargine use was substantially lower among participants who received tirzepatide, compared with insulin lispro. Insulin glargine was administered at a dosage 13 IU/day; insulin lispro was administered at a dosage of 62 IU/day. “At the highest dose, some patients stopped their insulin [glargine] in the tirzepatide arm,” said Juan Pablo Frias, MD, medical director and principal investigator of Velocity Clinical Research, Los Angeles, who presented the findings. “We demonstrated clinically meaningful and superior glycemic and body weight control with tirzepatide compared with insulin lispro, while tirzepatide was also associated with less clinically significant hypoglycemia.”
Weight improved for participants who received tirzepatide compared with those who received insulin lispro, at –10 kg and +4 kg respectively. The rate of clinically significant hypoglycemia (blood glucose < 54 mg/dL) or severe hypoglycemia was tenfold lower with tirzepatide, compared with insulin lispro.
The session dedicated to tirzepatide was comoderated by Apostolos Tsapas, MD, professor of medicine and diabetes, Aristotle University, Thessaloniki, Greece, and Konstantinos Toulis, MD, consultant in endocrinology and diabetes, General Military Hospital, Thessaloniki, Greece. Dr. Toulis remarked that, in the chronic disease setting, management and treatment intensification are challenging to integrate, and there are barriers to adoption in routine practice. “This is particularly true when it adds complexity, as in the case of multiple prandial insulin injections on top of basal insulin in suboptimally treated individuals with type 2 diabetes.
“Demonstrating superiority over insulin lispro in terms of the so-called trio of A1c, weight loss, and hypoglycemic events, tirzepatide offers both a simpler to adhere to and a more efficacious treatment intensification option.” He noted that, while long-term safety data are awaited, “this seems to be a definite step forward from any viewpoint, with the possible exception of the taxpayer’s perspective.”
Dr. Tsapas added: “These data further support the very high dual glucose and weight efficacy of tirzepatide and the primary role of incretin-related therapies amongst the injectables for the treatment of type 2 diabetes.”
Tirzepatide 5, 10, 15 mg vs. insulin lispro in addition to insulin glargine
The researchers aimed to assess the efficacy and safety of adding once-weekly tirzepatide, compared with thrice-daily prandial insulin lispro, as an adjunctive therapy to insulin glargine for patients with type 2 diabetes that was inadequately controlled with basal insulin.
Tirzepatide activates the body’s receptors for glucose-dependent insulinotropic polypeptide and glucagonlike peptide–1 (GLP-1). The study authors noted that “recent guidelines support adding an injectable incretin-related therapy such as GLP-1 receptor agonist for glycemic control, rather than basal insulin, when oral medications are inadequate.”
The open-label, phase 3b clinical trial drew data from 135 sites across 15 countries and included 1,428 adults with type 2 diabetes who were taking basal insulin. Participants were randomly assigned in a 1:1:1:3 ratio to receive once-weekly subcutaneous injections of tirzepatide (5 mg [n = 243], 10 mg [n = 238], or 15 mg [n = 236]) or prandial thrice-daily insulin lispro (n = 708).
Both arms were well matched. The average age was 60 years, and 60% of participants were women. The average amount of time patients had type 2 diabetes was 14 years; 85% of participants continued taking metformin. The average A1c level was 8.8% at baseline. Patients were categorized as having obesity (average body mass index, 33 kg/m2). The average insulin glargine dose was 46 units, or 0.5 units/kg.
Outcomes included noninferiority of tirzepatide (pooled cohort) compared with insulin lispro, both in addition to insulin glargine; and A1c change from baseline to week 52 (noninferiority margin, 0.3%). Key secondary endpoints included change in body weight and percentage of participants who achieved an A1c target of less than 7.0%.
About 90% of participants who received the study drug completed the study, said Dr. Frias. “Only 0.5% of tirzepatide patients needed rescue therapy, while only 2% of the insulin lispro did.”
Prior to optimization, the average insulin glargine dose was 42 IU/kg; during optimization, it rose to an average of 46 IU/kg. “At 52 weeks, those on basal-bolus insulin found their insulin glargine dose stayed flat while insulin lispro was 62 units,” reported Dr. Frias. “The three tirzepatide doses show a reduction in insulin glargine, such that the pooled dose reached an average of 11 units, while 20% actually came off their basal insulin altogether [pooled tirzepatide].”
Tirzepatide (pooled) led to the recommended A1c target of less than 7.0% for 68% of patients versus 36% of patients in the insulin lispro group.
About 68% of the patients who received tirzepatide (pooled) achieved the recommended A1c target of less than 7.0% versus 36% of patients in the insulin lispro group.
“Individual tirzepatide doses and pooled doses showed significant reduction in A1c and up to a 2.5% reduction,” Dr. Frias added. “Normoglycemia was obtained by a greater proportion of patients on tirzepatide doses versus basal-bolus insulin – one-third in the 15-mg tirzepatide dose.”