An open-label, three-centers, controlled, randomized, and crossover study containing 14 days of baseline period with standard of care (SOC) therapy followed by two-sessions of 4-weeks home study phase with Diabeloop closed-loop (CL) system comparing the declaration of meals and the non-declaration of meals.

Inclusion Criteria:

Device-related inclusion criteria

• age 12 - <18 years (i.e 17 years and 364 days) at time of screening
• Type 1 diabetes Study-specific inclusion criteria
• Subject has a clinical diagnosis of type 1 diabetes for at least 1 year as determined via medical records or source documentation by an individual qualified to make a medical diagnosis or confirmed C peptide negative.
• An insulin pump user, or patient under Multiple Daily Injection (MDI), with or without CGM experience.
• Subject having a Glycosylated hemoglobin (HbA1c) blood value > 8 % at time of screening visit-based on analysis from local laboratory within 3 months.
• Living in an area covered by a GSM (Global System for Mobile Communications) network
• Patient not isolated, does not live alone, or has a person living nearby who has a telephone and a key to his or her home
• Patient willing to wear the system continuously throughout the study
• Must be able to speak and be literate in French, in Dutch or in German
• Having provided written assent & parents/guardian having provided written informed consent

Exclusion Criteria:

Device-related exclusion criteria

• Patient receiving a total daily dose of insulin lower than 8 U

• Patient having severe uncorrected problems of hearing and/or visual acuity

• Patient unable to understand and perform all of the instructions provided by Diabeloop SA Study-specific exclusion criteria

• Subject is unable to tolerate tape adhesive around the sensor or pump placements

• Has any unresolved adverse skin condition in the area of sensor placement (e.g., psoriasis, dermatitis herpetiformis, rash, Staphylococcus infection)

• Has had any of the following cardiovascular events within 1 year of screening: myocardial infarction, unstable angina, coronary artery bypass surgery, coronary artery stenting, transient ischemic attack, cerebrovascular accident, angina, congestive heart failure, ventricular rhythm disturbances or thromboembolic disease

• Is being treated for hyperthyroidism at time of screening

• Has diagnosis of adrenal insufficiency

• Has taken any oral, injectable, or intravenous (IV) steroids within 8 weeks from time of screening visit, or plans to take any oral, injectable, or IV steroids during the study

• Females who are sexually active and able to conceive will be excluded if they are not using an effective method of contraception and do not agree to continue using an effective method of contraception for the duration of the study as determined by investigator.

• Actively participating in an investigational study (drug or device) wherein he/she has received treatment from an investigational study drug or investigational study device in the last 2 weeks

• Currently abusing illicit drugs

• Currently abusing marijuana

• Currently abusing prescription drugs

• Currently abusing alcohol

• Subject is using pramlintide (Symlin), DDP-4 inhibitor, liraglutide (Victoza or other GLP-1 agonists), metformin, canagliflozin (Invokana or other SGLT2 inhibitors) at time of screening

• Subject has elective surgery planned that requires general anesthesia during the study

• Has a sickle cell disease, hemoglobinopathy; or has received red blood cell transfusion or erythropoietin within 3 months prior to time of screening

• Plans to receive red blood cell transfusion or erythropoietin over study participation

• Diagnosed with current eating disorder such as anorexia or bulimia

• Diagnosed with chronic kidney disease that results in chronic anemia

• Hematocrit that is below the normal reference range of lab used

• Patient who has had a pancreatectomy or who has pancreatic malfunctions

• Patient with pancreatic islet transplantation or pancreas transplantation

• Patient on dialysis

• Patient with impaired hepatic functions

• Serum creatinine > 176 µmol/L

• Any other physical or psychological disease, or medication likely to interfere with the conduct of the study and interpretation of the study results as judged by the investigator.

• Pregnancy or breastfeeding

• Untreated coeliac disease (2 x ULN local laboratory)

• Untreated or unstable thyroid disease

• Subject has a history of 2 or more episodes of severe hypoglycemia, which resulted in any of the following during the 6 months prior to screening:

  • Medical assistance (i.e. Paramedics, Emergency Room or Hospitalization)
  • Coma
  • Seizures

• Subject having severe diabetic ketoacidosis in the 6 months prior to screening visit

• Impaired awareness of hypoglycemia (Gold Score > 4)