In this prospective, randomized, open-label, parallel group trial, the safety and efficacy of insulin degludec/insulin aspart (IDegAsp) twice daily will be compared with basal insulin once or twice daily plus pre-prandial insulin after 16 weeks of treatment in patients with type 1 diabetes. This trial will enable assessment of the clinically relevant endpoint of a change in HbA1c and Time in Range (TIR).

The objective of the current study is to investigate the efficacy and safety of IDegAsp twice daily compared to basal insulin once or twice daily plus pre-prandial insulin for 16 weeks in patients with type 1 diabetes mellitus. The primary endpoint in this study is the change from baseline in HbA1c. Patients with type 1 diabetes who meet the entry criteria are planned for inclusion in this trial. Approximately 40 patients will be enrolled in the study. Patients who qualify will be randomized to IDegAsp group or basal plus pre-prandial insulin group. Duration of treatment includes 2-week screening period, 16-week treatment observation period and 1-week follow-up.

Inclusion Criteria:

• Patients ≥ 18 and ≤75 years with type 1 diabetes;
• Diagnosed as T1DM ≥ 12 months before enrollment in the study;
• HbA1c ≥ 7.0 to ≤10.0%;
• Receipt of basal plus pre-prandial insulin and/or oral anti-diabetic agents ≥ 12 weeks before enrollment in the study;
• BMI ≤ 35kg / m2.

Exclusion Criteria:

• Patients with any of the following conditions will be excluded:
• Pregnant or lactating women
• Severe hypoglycemia within one month;
• Myocardial infarction, stroke or other severe cardiovascular events within 6 months prior to informed consent
• Receipt of Sulfonylureas, Meglitinides derivatives, Thiazolidinediones, Dpp-4 inhibitors or GLP-1 agonists within 3 months prior to informed consent;
• Current treatment with systemic steroids or immunosuppressive agents, or have immunologic deficiency disease at time of informed consent
• Severe mental instability, or alcohol abuse, or drug abuse
• Cancer within 5 years prior to informed consent
• Pancreatitis of severe infectious diseases within 1 months prior to informed consent
• Known hypersensitivity or allergy to the insulin
• Renal impairment (CKD-EPI eGFR<60ml/min)
• Impaired hepatic function, defined by serum levels of either ALT (SGPT), AST (SGOT), or alkaline phosphatase above 3 x upper limit of normal (ULN) as determined
• Participation in another trial within 2 months prior to informed consent
• Patients that investigators believe may fail to complete the study