according to a retrospective analysis of insurance claims data from more than 1 million individuals.
By January–March 2022, 56.6% of U.S. adults with type 2 diabetes prescribed an incretin-based treatment were taking a GLP-1 agonist and 38.7% were taking a DPP-4 inhibitor, Elisabetta Patorno, MD, and colleagues reported in an abstract released in advance of the annual meeting of the European Association for the Study of Diabetes.
These usage rates sharply diverged from the earliest period the researchers examined – 4 years earlier in January–March 2018 – when DPP-4 inhibitors were used by 62.4% of adults with type 2 diabetes on any incretin-based regimen and 37.6% were taking a GLP-1 agonist.
This shift was largely driven by accumulating evidence for clinically meaningful weight loss with GLP-1 agonists, especially semaglutide when used for people with type 2 diabetes as Ozempic (Novo Nordisk) or for treating people with obesity as Wegovy (Novo Nordisk).
Market share of GLP-1 agonists ‘likely to expand’ further
“The importance of the DPP-4 inhibitor class will further decrease when effective alternatives such as GLP-1 agonists and sodium-glucose cotransporter 2 inhibitors can be used,” said Alexander Kutz, MD, a coauthor of the report, in a statement released by EASD.
“The market share of GLP-1 agonists is likely to expand in patients with type 2 diabetes,” especially those who also have obesity, said Dr. Kutz, who like Dr. Patorno is a pharmacoepidemiologist at Brigham and Women’s Hospital in Boston.
Incretin-based agents currently account for roughly a third of all medications prescribed to people with type 2 diabetes, the authors said. GLP-1 is an incretin hormone, and receptor agonists mimic its action. The DPP-4 enzyme inactivates incretin hormones, and so inhibiting the enzyme boosts incretin activity.
The obesity-driven shift in positioning of agents for people with type 2 diabetes will likely extend to tirzepatide (Mounjaro), which acts as both a GLP-1 agonist and has agonist activity on the receptor for another incretin, glucose-dependent insulinotropic polypeptide. The Food and Drug Administration approved tirzepatide for type 2 diabetes in May 2022, too late for inclusion in the data the researchers reviewed. Plus, tirzepatide prescribing may lag for a few years as clinicians gain experience, and some might await results from the cardiovascular outcomes trial SURPASS-CVOT , said Dr. Kutz. SURPASS-CVOT has enrolled more than 13,000 adults with type 2 diabetes and is currently scheduled to finish by October 2024.
Injected semaglutide had the biggest gain
The study by Dr. Patorno and colleagues included 1,065,592 U.S. adults with type 2 diabetes taking an incretin-based medication in the Clinformatics Data Mart database maintained by Optum on claims it processed on behalf of various U.S. commercial insurers, including insurers that service certain Medicare beneficiaries.
The claims data had granularity for specific agents in the GLP-1 agonist class. Injected semaglutide, given once weekly, spiked from no use early in 2018 to a third of GLP-1 agonist use by the start of 2022.
However, use of liraglutide (Victoza, Novo Nordisk), a daily subcutaneous injection, dropped from a 44.2% share in early 2018 to 10.0% in early 2022. Dulaglutide (Trulicity, Lilly), a weekly injection, showed a small increase, from a 35.2% share in 2018 to 42.1% in 2022, and oral semaglutide (Rybelsus, Novo Nordisk) jumped from no use in 2018 to a 7.7% share in 2022. Among the DPP-4 inhibitors, sitagliptin (Januvia, Merck) was most commonly used, followed by linagliptin (Tradjenta, Boehringer Ingelheim) and saxagliptin (Onglyza, AstraZeneca). Use of all three DPP-4 inhibitors fell from 2018 to 2022.
Additional analyses showed that, compared with people starting a DPP-4 inhibitor during the period examined, those who started a GLP-1 agonist were 54%-64% more likely to have obesity and 18%-46% more likely to receive care from an endocrinologist. Those starting a GLP-1 agonist were also significantly less likely to have chronic kidney disease or dementia.
Although Dr. Kutz and Dr. Patorno foresee continued increases in the use of agents that act as GLP-1 agonists in U.S. adults with type 2 diabetes, they also stressed the ongoing role for sitagliptin and other DPP-4 inhibitors.
This class “may still be preferred in older and multimorbid patients at higher risk for frailty,” such as patients who live in nursing homes, they said in the EASD statement.
The study received no commercial funding. Dr. Patorno reported no relevant financial relationships. Dr. Kutz reported receiving an educational grant from Novo Nordisk, the company that markets semaglutide and liraglutide.
A version of this article appeared on Medscape.com.