U.S. prescribing data from 160,000 adults with type 2 diabetes and diabetic kidney disease showed a notable uptick in new prescriptions for sodium-glucose cotransporter 2 inhibitors and less dramatic gains for glucagonlike peptide–1 receptor agonists during 2019 and continuing into early 2020, compared with prior years, with usage levels of both classes during the first quarter of 2020 rivaling those of more traditional agents including metformin and insulin.
During the first 3 months of 2020, initiation of a SGLT2 inhibitor constituted 13% of all new starts of an antidiabetes drug among adults with type 2 diabetes and diabetic kidney disease (DKD). This compared with initiation rates during the same early 2020 period of 17% for GLP-1 receptor agonists, 19% for metformin, 16% for sulfonylureas, 15% for insulins, 14% for thiazolidinediones, and 6% for dipeptidyl peptidase–4 inhibitors, the seven drug classes examined in a study published in Diabetes Care.
Early 2020 was the first time that starts of a GLP-1 receptor agonist ranked second (behind only metformin) among these seven drug classes in the studied U.S. population, and early 2020 also marked an unprecedentedly high start rate for SGLT2 inhibitors that nearly tripled the roughly 5% rate in place as recently as 2018.
Rises are ‘what we expected’
The recent rise of SGLT2 inhibitors and GLP-1 receptor agonists in these patients “was what we expected,” given the evidence for both classes in slowing progression of DKD, said Julie M. Paik, MD, senior author on the study and a nephrologist and pharmacoepidemiologist at Brigham and Women’s Hospital in Boston.
“We’ve seen other beneficial drugs slow on the uptake, so it’s not surprising to see it here, and I’m optimistic” about further increases going forward, she said in an interview.
Both drug classes “were originally marketed as diabetes drugs,” and it is only since 2019, with the publication of trials showing dramatic renal benefits from canagliflozin (Invokana) in CREDENCE, and from dapagliflozin (Farxiga) in DAPA-CKD in 2020 that the evidence became truly compelling for SGLT2 inhibitors. This evidence also led to new renal-protection indications approved by the Food and Drug Administration for canagliflozin and for dapagliflozin, noted Dr. Paik.
Evidence for renal protection also emerged in 2017 for the GLP-1 receptor agonist liraglutide (Victoza) in the LEADER trial, and for dulaglutide (Trulicity) in the AWARD-7 trial, although neither drug has received a renal indication in its labeling.
By 2020, guidelines for managing patients with type 2 diabetes and chronic kidney disease from the influential Kidney Disease: Improving Global Outcomes organization had identified agents from the SGLT2 inhibitor class as top-tier options, along with metformin, for treating these patients, with agents from the GLP-1 receptor agonist class as the top third class to add in patients who require additional glycemic control.
Additional analyses Dr. Paik and associates ran showed how this played out in terms of which specialists prescribed these drugs during the full period studied beginning in 2013. Throughout this roughly 7-year span, about 70% of the prescriptions written for either SGLT2 inhibitors or for GLP-1 receptor agonists were from internal medicine physicians, followed by about 20% written by endocrinologists. Prescriptions from nephrologists, as well as from cardiologists, have hovered at about 5% each, but seem poised to start rising based on the recently added indications and newer treatment recommendations.
“It’s good to see the recent uptick in use since 2019,” Katherine R. Tuttle, MD, commented in an interview. It’s a positive development for U.S. public health, “but we need to do more to disseminate and implement these life-, kidney-, and heart-saving therapies.”