Evaluation of the MiniMed 780 System in Paediatric Subjects

Inclusion Criteria: 1. Aged 2 - 6 years at time of screening 2. Has a clinical diagnosis of type 1 diabetes for ≥ 6 months prior to screening as determined via medical record or source documentation by an individual qualified to make a medical diagnosis 3. Is on MDI therapy or CSII with or without CGM prior to screening 4. Has a glycosylated hemoglobin (HbA1c) \< 11% (97 mmol/mol) at time of screening visit as processed by a Local Lab 5. Is using or willing to switch to one of the following commercialized available insulins: Humalog (insulin lispro injection) and NovoLog (insulin aspart). 6. Must have a minimum daily insulin requirement (Total Daily Dose) of ≥ 6 units 7. Parent(s)/legal guardian(s) willing to upload data from the pump system, must have Internet access, a compatible computer or mobile phone that meets the requirements for uploading the study pump data at home. 8. Is living with one or more parent(s)/legal guardian(s) knowledgeable about emergency procedures for severe hypoglycemia and able to contact emergency services and study staff. 9. Investigator has confidence that the parent(s)/legal guardian(s) can successfully operate all study devices and is capable of adhering to the protocol 10. Subject and parent(s)/legal guardian(s) willingness to participate in all training sessions as directed by study staff. 11. Subject's parent/legal guardian must be willing and able to provide written informed consent. Exclusion Criteria: 1. Has Addison's disease, growth hormone deficiency, coeliac disease, hypopituitarism or definite gastroparesis, untreated thyroid disorder, or poorly controlled asthma, per investigator judgment. 2. Is using any anti-diabetic medication other than insulin at the time of screening or plan of using during the study (e.g. pramlintide, DPP-4 inhibitor, GLP-1, agonists/mimetics, metformin, SGLT2 inhibitors). 3. Has taken any oral, injectable, or intravenous (IV) glucocorticoids within 8 weeks from time of screening visit, or plans to take any oral, injectable, or IV glucocorticoids during the course of the study. 4. Has had renal failure defined by creatinine clearance \<30 ml/min, as assessed by local lab test ≤6 months before screening or performed at screening at local lab, as defined by the creatinine-based Cockcroft, CKD-EPI or MDRD equations. 5. Has any unresolved adverse skin conditions in the area of sensor placement (e.g. psoriasis, dermatitis herpetiformis, rash, Staphylococcus infection). 6. Is under Control IQ or CamAPS FX or other advanced hybrid closed loop therapy (e.g. DIY, MiniMed 780G) in the previous 3 months before enrollment. Note: For the continuation phase only, subjects using MiniMed 780G can be enrolled. 7. Is actively participating in an investigational study (drug or device) wherein he/she has received treatment from an investigational study drug or device in the last 2 weeks before enrollment into this study, as per investigator judgment. 8. Has any other disease or condition that may preclude the patient from participating in the study, per investigator judgment. 9. History of \>1 DKA event not related to illness or initial diagnosis in the last 3 months. 10. Parent(s)/legal guardian(s) are part of research staff involved with the study. 11. Parent(s)/legal guardian(s) are illiterate