This trial is a monocentric, randomised, double-blind, active comparator, controlled, 3-period cross-over trial.

In this monocentric, randomised, double-blind, active comparator, controlled, cross-over trial, each patient will be randomly allocated to a sequence of three treatments: one single dose of the co-formulation of insulin analog and pramlintide (also called ADO09), simultaneous separate injections of pramlintide and human insulin and one single dose of insulin lispro. To keep the blinding in this trial, a placebo injection will be given in addition to the ADO09 formulation and insulin lispro dose for a total of 2 injections per dosing visit. During each visit, meal test procedures will be performed and subjects will stay at the clinical centre until post-dose follow-up period has been terminated. IMP administration will be done subcutaneously immediately prior to test meal intake.

Inclusion Criteria:

• Type 1 Diabetes Mellitus (as diagnosed clinically) ≥ 12 months
• Treated with multiple daily injection ≥ 12 months
• Treated with insulin glargine U100 or U300 or insulin detemir at screening
• Fasting C-peptide ≤ 0.30 nmol/L
• BMI: 18.5-28.0 kg/m² (both inclusive)

Exclusion Criteria:

• Known or suspected hypersensitivity to IMPs, paracetamol or related products
• Type 2 Diabetes Mellitus
• Clinically significant abnormal haematology, biochemistry or urinalysis screening test, as judged by the investigator considering the underlying disease
• Presence of clinically significant acute gastrointestinal symptoms (e.g. nausea, vomiting, heartburn or diarrhoea), as judged by the investigator
• Known slowing of gastric emptying, including gastroparesis and or gastrointestinal surgery that in the opinion of the investigator, might change gastrointestinal motility and food absorption
• Intake of medication known to affect gastrointestinal motility, including but not limited to erythromycin, metoclopramide, cisapride, cholestyramine or colestipol within 4 weeks before screening