• Adult men or women (age ≥ 18 years);

• Diagnosis of Type 1 Diabetes (T1D) for more than 2 years at the start of screening;

• Body mass index (BMI) \> 16 kg/m2 and \< 35 kg/m2;

• Well managed intensive SubCutaneous (SC) insulin therapy, i.e. patient using for at least 3 months:

‣ CSII, whatever the insulin pump used, and

⁃ Continuous Glucose Monitoring (CGM), by using Dexcom G6;

• 7.0% \< Serum HbA1c \< 12.0%;

• Patient characterized by one of the following conditions:

‣ Unstable diabetes/poor glycemic control, meaning patient presenting:

• at least one episode of severe hypoglycemia during the 12 months prior to study screening. Severe hypoglycemia is defined by American Diabetes Association (ADA) standards as severe cognitive impairment requiring assistance from another person for recovery (as per ADA's definition in standards of care in diabetes);

∙ or glycemic excursions (post-prandial hyperglycemic or nocturnal hypoglycemic episodes) considered as too frequent and of high amplitude by the investigator, during the previous month;

⁃ Presence of adverse side effects of SC insulin-therapy:

• SC insulin resistance;

∙ or severe acquired lipodystrophy resistant to pump treatment;

∙ or genetic skin atrophy or lipodystrophy.