DISCOVER Details Gradual Uptake, Need for Improvement in Prescribing of SGLT2 Inhibitors, GLP-1 RAs

Suzanne Arnold, MD

A review of data obtained from within the DISCOVER registry is offering clinicians insight into the prevalence of GLP-1 receptor agonists and SGLT2 inhibitors.

Presented at ADA 2021, information from the registry describes a slow, but gradual uptake in SGLT2 inhibitors but also outlines gaps in prescribing that leave many patients who could benefit the most without these medications.

A global registry assessing use of GLP-1 receptor agonists and SGLT2 inhibitors as second-line therapies among patients with type 2 diabetes, DISCOVER was designed with the intent of developing a greater understanding of not only the prevalence, but also factors associated with use of these therapies in a large, prospective database. For more on the results from DISCOVER, Endocrinology Network reached out to study presented Suzanne Arnold, MD, of the St. Luke’s Mid-America Heart Institute, and that conversation can be found below.

Editor’s Note: This transcript has been edited for clarity.

Endocrinology Network: Can you describe DISCOVER and what data it provided?

Suzanne Arnold, MD: So, DISCOVER is a very large, prospective registry, with almost 16,000 patients across 38 countries, 6 continents. It was really designed to capture processes of care, treatment patterns, and complications over time. It enrolled patients, at the time second line, glucose-lowering therapy was started—this could be as an add-on or it could be a shift. Also, the initial treatment for diabetes could not be an injectable—so, it eliminated people who went on insulin as first-line.

So, it's really looking at that time point when you have to make a decision about a second-line therapy. What we were hoping to find was that there would be a significant uptake in the use of SGLT2 inhibitors and GLP-1 receptor agonists over time, but also in targeted use. So, higher use in those most likely to benefit—patients with known cardiovascular disease or who are very high risk.

Prior studies, including one we conducted out of a large us registry, show the uptake has been had been pretty low. Another study from EASD in the fall was another global registry, but of more high-income countries—they also showed a fairly low uptake.

What we saw was similar, but actually slightly encouraging. As second-line therapy, about 11% of the patients were started on either a GLP-1 receptor agonist or SGLT2 inhibitor. At the end of three years, that increased to 17%. The primary increase that we saw over time was with SGLT2 inhibitors. The use of GLP-1 receptor agonists almost flat throughout the 3 years.

Our primary outcome was the use of one of those medicines. So, if a patient was on at least one medication with proven cardiovascular risk reduction at the end of the three years of the study, that was considered, I don't say win, but that was a positive.

EN: Were there any other findings of note?

SA: When we looked at it in particular patient subgroups, we found that patients with coronary disease and patients with heart failure were a little bit more likely to be prescribed the medications more— in the range of 20-23% of the patients with those diagnosis. We also looked at diagnoses that developed through the time period of the study. So, if you had a diagnosis of coronary disease that developed at year 2, that was kind of included in that definition.

Interestingly, once we accounted for patient factors as well as the other comorbidities. Patients with peripheral artery disease or chronic kidney disease were actually less likely to be put on one of the medications. So, we see some targeted use, but not to the degree that we would like to see.

DISCOVER had many different specialties of physicians who enrolled in the study. So, we were able to look at use the medications across different specialties. We broke this down by endocrinology, primary care, cardiology, and then we grouped the others together.

It seems like the cardiologists were more likely to be using SGLT2 inhibitors. Then the other thing we looked at, which is always a really interesting thing in these global registries, was variability across countries. I guess not surprisingly, there's quite a bit of variability across countries, but not a lot of geographic trends.

We looked across multiple continents—Europe, Americas, Asia—and there weren’t geographic trends towards higher use in particular areas, but we did also look at the association of use across gross national income for country. So, trying to look at countries that have more resources and determine if they are they using these medications more. We did observe a bit of a trend towards a higher use of other medications.

EN: What do you think the take-home message of this data should be?

SA: At the end of the day, we see that use is better than it had been before and it's increasing over time, particularly with the use of SGLT2 inhibitors. There's a bit of targeted use, but not enough, particularly among patients with heart failure or chronic kidney disease, and a lot of variability across country exists, which really speaks towards the concern of structural issues that are keeping us from using these medications more.