Background: The PROMISE Clinical Study was conducted to determine the accuracy and safety of the next generation implantable CGM System. A subset of 43 subjects had a sensor implanted with modified chemistry referred to as sacrificial boronic acid (SBA) , to protect the boronic acid glucose-binding moieties from degradation. This post-hoc analysis investigated the effect of SBA on accuracy through 180 days using different calibration (cal) schemes.

Methods: Data from the PROMISE Clinical Study from participants with SBA sensors was run through an algorithm emulator with cals of 1/day, 2/day, or using a dynamic cal scheme switching between 1-2/day, all starting on day 22 (day 1-21 had fixed 2 cals/day) . MARD was analyzed by glucose ranges and days of sensor wear through 180 days.

Results: The Table shows the MARD by glucose ranges and cal frequency. MARD (%) by days of sensor wear demonstrated: 9.6, 9.4, 9.2 on days 1-30; 9.5, 8.6, 8.3 on days 31-60; 7.7, 7.4, 7.6 on days 61-90; 8.3, 8.0, 7.9 on days 91-120; 9.6, 8.8, 7.5 on days 121-150; and 7.0, 7.3, 6.9 on days 151-180, respectively, for 1 cal/day, dynamic cal, and 2 cals/day.

Conclusions: The SBA sensor maintains an overall MARD less than 9.0% by glucose range and 9.6% by days of sensor wear through 180 days, whether it has a cal scheme of 1, dynamic, or 2 cal per day. By reducing sensor degradation with the SBA chemistry modification, the sensor maintains long-term accuracy with 1 cal/day.


A.E.Jacquin: Employee; Senseonics, Other Relationship; BrainScope Company, Inc. L.Al-khawi: None. S.Ghosh-dastidar: Employee; Senseonics. K.S.Tweden: Employee; Senseonics. F.R.Kaufman: Consultant; Twin Health, Employee; Senseonics.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at