Safety and Effectiveness of an Investigational Insulin Delivery Device Providing Basal/Bolus Therapy with Rapid-Acting or Regular Human Insulin in Adults with Type 2 Diabetes

Background: This study undertook to assess usability, 24-h glycemic profiles, and safety of an investigational basal/bolus insulin delivery device (IDD) providing rapid-acting or regular human insulin (RHI) for people with type 2 diabetes (T2D) transitioning from multiple daily insulin injections (MDIs). Methods: This prospective, single-center, open-label two-period study enrolled adults with T2D and glycated hemoglobin (HbA1c) 7%-11% (53-97 mmol/M). Participants continued the usual MDI therapy during a 2- to 3-day in-clinic MDI period and then within 7 days were switched to the IDD, using current insulin dose, for a 6-day in-clinic IDD period, with blinded continuous glucose monitoring throughout the in-clinic periods. Results: We enrolled 21 participants (mean +/- standard deviation age 57 +/- 8 years; HbA1c 8.2% +/- 0.9% [66 +/- 9.8 mmol/M]) using U-100 insulin lispro (n = 11) or who switched to U-100 RHI (n = 10). Glycemic measures improved from the MDI to IDD period, including fasting blood glucose (BG), 141.2 +/- 38.3 mg/dL (7.8 +/- 2.1 mmol/L) versus 121.2 +/- 35.0 mg/dL (6.7 +/- 1.9 mmol/L; P = 0.002), respectively; 24-h mean BG, 137.0 +/- 20.5 mg/dL (7.6 +/- 1.1 mmol/L) versus 125.0 +/- 16.5 mg/dL (6.9 +/- 0.9 mmol/L; P = 0.004); and time in range (at 70-180 mg/dL; 3.9-10 mmol/L), 81.0% +/- 14.4% versus 87.5% +/- 10.6% (P = 0.008). No significant differences between MDIs and IDD use were recorded for time <70 mg/dL (1.6% +/- 2.7% vs. 3.1% +/- 2.7%, P = 0.08), CV%, or mean of daily differences. Mean amplitude of glycemic excursions was significantly lower with the IDD (P = 0.011). There were no significant differences between insulin lispro and RHI for any glycemic measure. No serious adverse events were recorded. Conclusions: In the context of this exploratory study, the IDD was safe and effective to administer insulin lispro and RHI for adults with T2D.