ADA 2021: Infusion Set Survival and Performance of Medtronic Extended-Wear Infusion Set

Real-world data for the Medtronic Extended-Wear Infusion Set revealed at the 81st American Diabetes Association scientific session. 

Medtronic has advanced its Continuous Subcutaneous Insulin Infusion (CSII) pump system. Previous systems had extended wear of two to three days, but newer models now have extended wear of up to seven days. There was an improvement to insulin stability and infusion set site with the new extended-wear H-cap connector. New tubing systems improved insulin preservative retention and stability, and the adhesive patch improved adherence to the skin.  

The purpose of the study was to collect data to support the six or seven days of the extended-wear infusion set. A single-arm non-inferiority was conducted at 15 investigational sites with data from 259 participants. The primary endpoint assessed was the rate of infusion set failure due to unexplained hyperglycemia by day six of infusion. The secondary endpoint evaluated was the rate of infusion set failure due to unexplained hyperglycemia at the end of day seven. Baseline characteristics and demographics were collected at baseline. Participants were given a MiniMed 670G system with either Humalog or Novolog insulin for two weeks. After two weeks, participants wore extended-wear insulin set for 12 repeated wears of 174 hours or until set failure. Researchers defined unexplained hyperglycemia as glucose reported as >250mg/dL, failure of a correction dose to lower study glucose by 50mg/dL, or one correction dose after the first correction dose.  

Results of the study determined no new safety issues associated with the extended-wear infusion set. Two events of severe hypoglycemia were reported; however, the events were not device-related. In addition, 104.1 events of severe hyperglycemia were reported. The study achieved primary and secondary endpoints. Researchers observed the rate of infusion set failure of 0.06% and 0.27% after six days in the Humalog and Novolog groups in the primary endpoint. The secondary endpoint was marked as a rate of infusion set failure of 0.13% and 0.41% after seven days in the Humalog and Novolog groups. There was no significant increase in HbA1c levels and the total daily dose of insulin, which confirmed the safety of seven days of extended wear. Overall performance of the extended-wear infusion set was equivalent to current infusion sets when used for three days.  

Data from this study confirm the efficacy and comfortable use. The extended-wear infusion set sets itself apart as innovative technology by addressing insulin degradation and preservative loss. Circumventing these issues could reduce the amount of insulin wasted and plastic that is thrown away. In addition, there is a reduced user burden on individuals as the infusion set lasts up to seven days compared to standard infusion sets.  

Practice Pearls: 

• Extended-wear infusion set currently undergoing FDA review. 
• No significant increase in HbA1c levels was observed in the seven-day use of the infusion device. 
• Insulin degradation and preservative loss issues were addressed with improved extended-wear tubing.  

Buckingham, B. A et al. (2021, June). Infusion Set Survival and Performance during the Medtronic Extended-Wear Infusion Set (EWIS) Pivotal Trial. American Diabetes Association virtual symposium. (ADA Symposium login required) 

Torré Anderson, II, Fourth Year Doctor of Pharmacy Candidate, Florida A&M University College of Pharmacy and Pharmaceutical Sciences, Institute of Public Health