63-OR: Towards Point-of-Care Devices: First Evaluation of an Insulin Immunosensor for Type 1 Diabetes
Authors: WOLKOWICZ KELILAH L. , VARGAS EVA , TEYMOURIAN HAZHIR , TEHRANI FARSHAD , PINSKER JORDAN E. , CHURCH MEI MEI , PIPER MOLLY , DOYLE FRANCIS J. , PATTI MARY-ELIZABETH , LAFFEL LORI M. , WANG JOSEPH , DASSAU EYAL 
Published: June 2020

Insulin monitoring is clinically relevant for diabetes management. We present a first evaluation of an insulin immunosensor as a step towards point-of-care devices to enhance automated insulin delivery for T1D. The sensor is a novel, wearable, minimally invasive microneedle/microfluidic device for real-time insulin monitoring. To validate the sensor, a mid-study analysis was performed on 4 adults with T1D (43±12 years, 75% male) using insulin pumps. Insulin lispro or aspart was injected via syringe just prior to breakfast. Insulin levels were collected prior to injection and over the next 4h. Insulin quantification was performed using the participants’ serum samples extracted from venous blood. The change in real-time immunosensor-measured insulin levels was compared with values obtained by ELISA in a central lab. At each time point, a median insulin level was derived from replicate immunosensor samples. Concordance of immunosensor and ELISA insulin levels was assessed as a comparison of their changes from baseline (Figure). The mean absolute relative difference between immunosensor and venous insulin levels was 16%, 8%, and 18% at 1, 2, and 4h after the baseline measurement, respectively. The results of the 1st phase real-time insulin immunosensor evaluation are promising and may provide data to improve current insulin decay curve assumptions used in insulin-on-board approximations.

Disclosure
K.L. Wolkowicz: None. E. Vargas: None. H. Teymourian: None. F. Tehrani: None. J.E. Pinsker: Advisory Panel; Self; Medtronic. Consultant; Self; Eli Lilly and Company, Tandem Diabetes Care. Research Support; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Tandem Diabetes Care. Speaker’s Bureau; Self; Tandem Diabetes Care. M. Church: None. M. Piper: None. F.J. Doyle: Research Support; Self; DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Stock/Shareholder; Self; Mode AGC. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care. M. Patti: Consultant; Self; Fractyl Laboratories, Inc. Research Support; Self; Dexcom, Inc., Xeris Pharmaceuticals, Inc. Other Relationship; Self; Academy of Nutrition and Dietetics, American Diabetes Association, American Society of Metabolic and Bariatric Surgery, Endocrine Society, Insulet Corporation, King Abdullah International Medical Research Center, SUNY Downstate. L.M. Laffel: Advisory Panel; Self; Roche Diabetes Care. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Insulogic LLC, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc., Sanofi US. J. Wang: None. E. Dassau: Consultant; Self; Eli Lilly and Company. Research Support; Self; Dexcom, Inc., DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; Roche Diabetes Care. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care.

Funding
The Leona M. and Harry B. Helmsley Charitable Trust (2018PG-TID061); Dexcom, Inc. (IIS-2019-052)