Algorithm optimization of a new continuous glucose monitoring system in children, adolescents and adult patients with type 1 diabetes – A pilot study.

This is a prospective, single arm, open label study is to collect data for algorithm optimization of a novel continuous glucose monitoring (CGM) device by evaluating the glucose measured in comparison with an already commercially available CGM system (referred to as aCGM) and the reference standard which is capillary blood glucose in children, adolescents and adult patients with type 1 diabetes. The study will enrol 15 children and adolescents (2-17 years of age) and 15 adults (18 years and over). The novel CGM system consists of an interstitial glucose sensor worn in the upper arm continuously for up to 15 days, which is scanned by a hand-held reader to display glucose data, including the current glucose level and a predicted glucose trend. Participants will not use the investigational novel CGM device (from here onwards referred to as nCGM) to make clinical or treatment decisions. Both aCGM and nCGM consist of (1) a sensor worn on the upper arm that measures the glucose concentration in the interstitial fluid, (2) a transmitter that send the results wirelessly and (3) a handheld receiver (e.g. mobile phone), that receives and displays the glucose data. While aCGM can be worn for up to 10 days, nCGM can be worn for up to 15 days. Subjects are involved in the study for 15 days. To ensure that the study procedures are feasible and no safety signals are present, the initial 5 subjects will be adults aged 18 years and over, before the study commences in younger participants. Subjects will wear nCGM for 15 days to monitor the glucose values while maintaining their usual treatment method. On day 1 of the study, subjects will receive training on the use of the CGM devices and the self-monitoring blood glucose device CareSens Dual (hereinafter referred to as SMBG) for measuring of capillary blood glucose, and will be instructed to keep a daily blood glucose log. The training on the use of the CGM devices will be done by a trained member of the research team and take approximately 30 minutes. Depending on the age group, subjects will wear between 1 – 3 CGM devices simultaneously. Those < 8 years old, 1 nCGM device, and on the consent of the parent/guardian, 1 additional aCGM device (up to 2 devices in total). For 8-12 age group, 1 nCGM sensor (+ 1 additional if consented) and 1 aCGM sensor (up to 3 devices in total), and for age group >= 13 years, 2 nCGM sensors and 1 aCGM sensor will be worn (3 devices in total). All procedures at the clinic will be performed by trained nurses, who are involved in the study. After putting on the CGM devices on day 1, and again when subjects re-visit the clinic on days 8 and 15, the subjects will perform blood sampling every 15 - 30 min for 2-8 hours, depending on their age (30-minute interval sampling for 2 hours for those <8 year old; 15-minute interval sampling for 4 hours for 8-12 year olds; for 6 hours for 13-17 year olds, for 8 hours for >=18 year olds). On day 1, a maximum of 4 hours of blood sampling will be performed to reduce the length of the first in-clinic day. On these in-clinic days, capillary blood will be taken from all subjects via fingerprick, and additionally venous blood will be taken for cobas measurements (CM) from 6 adult subjects aged 18 years or older, if specific consent is given. Subjects will calibrate all CGM devices once every 12 hours during the first day of the study (Day 1), and thereafter once every 24 hours (days 2 to 15), using SMBG. At home on days 2-7 and 9-14, subjects will conduct SMBG measurements and fill out their daily blood glucose log. These SMBG measurements will be in total conducted 8 – 25 times a day, depending on the subject’s age and the day during the clinical trial. At home, subjects will be instructed to test their blood glucose 8 times daily (more if required) and record all values. On days 4, 7 and 13, subjects will additionally perform cluster testing as followed: 2-7 year-olds 60-min interval SMBG testing for 4 hours; 8-12 year-olds 30-min SMBG testing for 4 hours, 13 years and over 15-min interval SMBG testing for 4 hours. The study ends after completing the in-clinic blood sampling and final safety assessments on day 15.