Diabetes Dialogue: The G7 15-Day System and CGM Innovations at Dexcom, With Jessica Castle, MD

Welcome back to Diabetes Dialogue: Technology, Therapeutics, & Real-World Perspectives!

In this episode of Diabetes Dialogue, host Diana Isaacs, PharmD, is joined by Jessica Castle, MD, vice president of medical affairs at Dexcom, to discuss the company’s recent innovations in continuous glucose monitoring (CGM) and their clinical implications.

To open the episode, Castle outlines the launch of the Dexcom G7 15-day system, highlighting its extended wear duration, improved accuracy (MARD ~8%), and strong early adoption among adults. She notes ongoing efforts to optimize sensor longevity, particularly through adhesive enhancements, while acknowledging that pediatric expansion remains under evaluation due to unique wear challenges in children. Integration with automated insulin delivery systems continues to evolve, with further updates anticipated.

The discussion then shifts to Dexcom’s newly cleared Smart Basal feature, designed to address persistent clinical inertia in basal insulin titration for type 2 diabetes. Castle explains how clinician-defined parameters within the Dexcom Clarity platform enable automated daily dose adjustments based on CGM data, with the goal of minimizing both hyperglycemia and hypoglycemia. Early data presented at ATTD demonstrate significant improvements in mean glucose (>40 mg/dL reduction) and time in range (>20 percentage point increase), without increased hypoglycemia, underscoring both the safety and efficacy of this approach.

Isaacs and Castle also explore recent advancements in Dexcom’s digital ecosystem, including AI-driven meal detection and nutritional analysis within the Stelo and G7 platforms. These tools facilitate real-time behavioral insights, reinforcing CGM’s role as a powerful driver of lifestyle modification. Castle emphasizes the growing integration of artificial intelligence to deliver actionable, personalized feedback while maintaining clinical reliability.

Expanding beyond glycemic metrics, Castle reviews emerging real-world evidence supporting CGM use across diverse populations. Retrospective analyses presented at ATTD demonstrate substantial reductions in diabetic ketoacidosis (DKA), including >90% risk reduction in pediatric type 1 diabetes following CGM initiation. Additional registry data in non-insulin-treated type 2 diabetes show meaningful A1C reductions (~0.6%) and associated weight loss, reinforcing the value of CGM beyond insulin-dependent populations. The conversation also highlights complementary benefits when CGM is used alongside newer pharmacotherapies, including GLP-1 receptor agonists and dual incretin agents.

The episode further addresses gaps in evidence, particularly in pregnancy. While CGM adoption is increasing and supported by growing data in gestational diabetes, Castle acknowledges limited evidence in preexisting type 2 diabetes during pregnancy. Ongoing studies, including the IMAGINE trial, aim to evaluate earlier CGM implementation and its potential to improve maternal and fetal outcomes, potentially reshaping current screening paradigms.

The discussion concludes with a forward-looking perspective on Dexcom’s innovation pipeline. Castle highlights Smart Basal and the G7 15-day system as near-term practice-changing tools, alongside continued advancements in sensor design, accuracy, and usability. Both speakers emphasize the expanding role of CGM as a foundational technology in diabetes management, supporting a more proactive, data-driven, and patient-centered approach to care across clinical settings.

Editor’s Note: Isaacs reports disclosures with Dexcom, Abbott, Lilly, Novo Nordisk, Medtronic, Insulet, and others.