Accuracy of the 15.5-Day G7 iCGM in Adults with Diabetes

Background: Continuous glucose monitors (CGM) are increasingly being used to manage diabetes. We evaluated the performance and safety of an investigational 15-day G7 integrated CGM (iCGM; Dexcom) in adults with diabetes. Methods: This prospective, multicenter study enrolled adults (age ≥18 years) with type 1 diabetes (T1D) or type 2 diabetes (T2D) at six clinical sites in the United States. Four in-clinic visits were conducted on days 1-3, 4-7, 9-12, and 13-15.5, with frequent arterialized venous blood draws for comparator measurements using a Yellow Springs Instrument (YSI) 2300 Stat Plus glucose analyzer. Participants with T1D or T2D using intensive insulin therapy participated in clinic sessions with deliberate, closely monitored glucose manipulations. Accuracy evaluations included the mean absolute relative difference (MARD), proportion of CGM values within 15 mg/dL of YSI values <70 mg/dL or within 15% of YSI values ≥70 mg/dL (%15/15), as well as %20/20, %30/30, and %40/40 agreement rates. Performance related to iCGM special controls, user experience, and device safety were also assessed. Results: The study enrolled 130 adults with diabetes (mean ± standard deviation age 43.0 ± 14.4 years, 53.1% female, 86.9% with T1D) and analyzed 20,310 CGM-YSI matched pairs from 130 15-day G7 CGM devices. The overall MARD was 8.0% and the %15/15, %20/20, %30/30, and %40/40 agreement rates were 87.7%, 94.2%, 98.9%, and 99.8%, respectively. The device exceeded iCGM performance goals, and user experiences were broadly positive. No serious adverse events were reported. Conclusions: The 15-day G7 iCGM was accurate and safe in adults with diabetes throughout the 15.5-day wear period. Clinicaltrials.gov: NCT05263258.