Clinical Professor, Cumming School of Medicine, and Child Health & Wellness Researcher, Alberta Children's Hospital Research Institute, at University of Calgary

Lois Donovan, MD

HCPLive Five at ADA Scientific Sessions 2025

2025 American Diabetes Association (ADA) Scientific Sessions, held June 20–23 in Chicago

, reflected a shifting paradigm in diabetes care prioritizing comprehensive approaches to glucose management, cardiometabolic health, and patient-centered outcomes. This year’s meeting featured a diverse slate of groundbreaking research spanning automated insulin delivery, weekly insulin alternatives, and novel interventions tackling unique drivers of glycemic dysregulation.

Among the most talked-about data were CIRCUIT trial findings on automated insulin delivery systems improving time-in-range during pregnancy; the QWINT program’s demonstration that once-weekly insulin efsitora alfa can effectively replace daily basal insulin; and evidence supporting prediabetes remission as a superior goal to weight loss for type 2 diabetes prevention. Additional highlights included the CATALYST trial’s success with mifepristone in hypercortisolism-related diabetes and the STRIDE trial’s new insights into semaglutide’s effects on walking capacity and disease progression in patients with type 2 diabetes and peripheral artery disease.

Hybrid Closed Loop Insulin Improves Time in Range for T1D During Pregnancy, with Lois Donovan, MD, and Denice Feig, MD, MSc

The CIRCUIT trial compared an automated insulin delivery (AID) system using Control-IQ technology to standard care in pregnant women with type 1 diabetes, presented at ADA 2025 by Lois Donovan, MD, and Denice Feig, MD. Participants using the hybrid closed-loop system achieved a 12.6% (95% CI, 9.9–15.2; 

<.001) higher time in range during pregnancy (TIRp) compared with standard care (65.4% vs. 50.3%). Additionally, the AID group had 11.4% (95% CI, 8.6–14.2; 

<.001) less time above range, 1.04% (95% CI, 0.6–1.48; 

<.001) less time below 63 mg/dL, and a mean glucose 11.2 mg/dL lower than standard care (95% CI, 7.2–16.2; 

Once-Weekly Insulin Efsitora a Practical Option for Type 2 Diabetes, with Athena Philis-Tsimikas, MD

The QWINT-3 phase 3 trial investigated weekly insulin efsitora alfa versus daily insulin degludec in patients with type 2 diabetes switching from basal insulin, presented at ADA 2025 by Athena Philis-Tsimikas, MD. Weekly efsitora injections were non-inferior to daily degludec for glycemic control, supporting its potential as a practical alternative. Philis-Tsimikas noted the findings suggest switching to weekly insulin could substantially reduce treatment burden for patients.

Glycemic Control Trumps Weight Loss for Type 2 Diabetes Prevention, with Arvid Sandforth, MD

A prediabetes lifestyle intervention study presented by Arvid Sandforth, MD, at ADA 2025 showed achieving normal glycemia, regardless of weight change, provided the same protective effect against developing type 2 diabetes. Participants achieving glycemic remission experienced significantly reduced T2D incidence even if they maintained or gained weight, compared to those who did not normalize glycemia. The multicenter German study highlighted that while weight loss remains a powerful tool, achieving glycemic control should be prioritized as the primary prevention target.

Diabetes Dialogue: CATALYST Trial, Mifepristone, and Hypercortisolism in T2D, with John Buse, MD, PhD

The phase 4 CATALYST trial enrolled 1055 adults with type 2 diabetes and HbA1c >7.5% despite optimized therapy, screening for hypercortisolism using dexamethasone suppression testing, which identified a 24% prevalence (95% CI, 21.4–26.7%). In part 2, 136 patients with confirmed hypercortisolism were randomized 2:1 to mifepristone or placebo for 24 weeks, with mifepristone reducing HbA1c by 1.3 percentage points versus placebo (95% CI, –1.81 to –0.83; 

 <.001). Secondary outcomes showed reductions of 5.12 kg in body weight (95% CI, –8.20 to –2.03) and 5.1 cm in waist circumference (95% CI, –8.23 to –1.99) relative to placebo.

New Data Supports Protective Vascular Effects of Semaglutide in T2D and PAD, with Subodh Verma, MD, PhD

The STRIDE trial randomized 792 adults with T2D and PAD to semaglutide (n=396) or placebo (n=396) for 52 weeks, presented by Subodh Verma, MD, PhD, at ADA 2025. Patients receiving semaglutide showed a median baseline-adjusted maximum walking distance ratio of 1.21 compared with 1.08 for placebo. Semaglutide also reduced the risk of a composite disease progression endpoint—including death, major adverse limb events, or rescue medication use—by 54% relative to placebo.

These 5 represent only some of the data the 

 team covered at this year's meeting! Check out more KOL insight and our full conference coverage on our 

Videos

From uncovering new benefits of semaglutide to targeting hypercortisolism in people with type 2 diabetes, here are 5 key updates from the annual meeting.

Hybrid Closed Loop Insulin Yields More Time in Range for T1D During Pregnancy, with Lois Donovan, MD, and Denice Feig, MD, MSc

An automated insulin delivery (AID) system using Control-IQ Technology demonstrated an improved time in blood glucose pregnancy range (TIRp) from standard care in women with 

These findings, from the open-label CIRCUIT trial, were presented by co-primary investigator Lois Donovan, MD, endocrinologist and Clinical Professor, Cumming School of Medicine, and Child Health & Wellness Researcher, Alberta Children's Hospital Research Institute, at University of Calgary at the 

2025 American Diabetes Association (ADA) Scientific Sessions

caught up with Donovan as well as the study’s other co-primary investigator, Denice Feig, MD, MSc, Professor of Medicine, University of Toronto, and Head of the Diabetes and Endocrine in Pregnancy Program at Mount Sinai Hospital, to learn more about CIRCUIT and its promising findings.

Feig also serves as an Adjunct Scientist at the Institute for Clinical and Evaluative Sciences, is a Member of the Motherisk Team at SickKids Hospital, and was Past Chair of the Diabetes in Pregnancy Interest Group for the ADA.

Donovan and Feig gave an overview of the Control-IQ technology used in the study, which was combined with an insulin pump and a Dexcom G6 sensor. They shared their excitement over the preliminary findings, which included a 12.6% (95% CI, 9.9-15.2; 

<.001) higher TIRp with HCL than standard care (65.4%; standard deviation [SD], 9.5% versus 50.3%; SD, 13.9, respectively). HCL was also associated with 11.4% (95% CI, 8.6–14.2; 

 <.001) less time above range and 1.04% (95% CI, 0.6–1.48; 

 <.001) less time below 63 mg/dL, along with an adjusted mean glucose 11.2 mg/dL (0.62 mmol/L) lower than standard care (95% CI, 7.2–16.2; 

"We're really excited to share with you that we found a 12.6% point improvement in the closed loop group compared to the standard care group... that equates to 3 more hours per day spent in pregnancy time in range, which, as Denice has already beautifully pointed out in previous work, will be very impactful on the pregnancy outcomes. Certainly, this study was not powered to look at pregnancy outcomes, but we're really very excited by how well it worked," Donovan said.

Donovan’s disclosures include Medtronic, Dexcom, Inc., Tandem Diabetes Care, Inc, and Inner Analytics.

Donovan LE, Lemieux P, Dunlop A, et al. A Randomized Multicenter Trial of Hybrid Closed-Loop Insulin Therapy with Control-IQ Technology in Type 1 Diabetes in Pregnancy. Presented at ADA 2025; June 20-23; Chicago, Illinois. Poster #2084-LB

Smart Insulin Tech Helps Pregnant Women with Type 1 Diabetes Maintain Target Blood Glucose Levels. News release. ADA. June 20, 2025. https://www.prnewswire.com/news-releases/smart-insulin-tech-helps-pregnant-women-with-type-1-diabetes-maintain-target-blood-glucose-levels-302487332.html

Donovan and Feig shared exciting findings and further research from a study evaluating an insulin pump with Control-IQ technology with Dexcom G6 sensor.

Evolving Care for T1D in Pregnancy, with Lois Donovan, MD; and Denise Feig, MD, MSc

An automated insulin delivery (AID) system using Control-IQ Technology allowed women with 

 (T1D) in early pregnancy to remain in target blood glucose range for longer than with standard care.

These findings, from an open-label trial, were presented at the 

, held June 20-23, in Chicago, Illinois, by co-primary investigator Lois Donovan, MD, endocrinologist and Clinical Professor, Cumming School of Medicine, and Child Health & Wellness Researcher, Alberta Children's Hospital Research Institute, at University of Calgary.

During the meeting, HCPLive spoke with Donovan as well as the study’s other co-primary investigator, Denice Feig, MD, MSc, Professor of Medicine, University of Toronto, and Head of the Diabetes and Endocrine in Pregnancy Program at Mount Sinai Hospital, to learn more about how T1D care for pregnant women continues to evolve. Feig also serves as an Adjunct Scientist at the Institute for Clinical and Evaluative Sciences, is a Member of the Motherisk Team at SickKids Hospital, and was Past Chair of the Diabetes in Pregnancy Interest Group for the ADA.

Donovan emphasized how far care has come in the last decade and how new research continues to push the envelope. Furthermore, Feig discussed the CONCEPTT trial she investigated in several years ago and how it helped to enable continuous glucose monitoring (CGM) in pregnant people with diabetes, but emphasized that it was a step in the right direction and more work remains to be done to improve outcomes and care.

"We've got some really helpful things that are so much better [for T1D in pregnancy care] than even 8 years ago. And that's what this is all about, making it better for patients to have better outcomes, and making it easier on them," Donovan said.

Automated insulin delivery systems enhance blood glucose control for pregnant women with type 1 diabetes, potentially advancing  diabetes care.

Lois Donovan, MD

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