Primary Objective:

To compare the pharmacokinetic (PK) characteristics of single doses of insulin glargine given as U200 and U500 with those of a single dose (SD) of Lantus® U100 in a euglycemic clamp setting in subjects with type 1 diabetes.

Secondary Objectives:

To compare the metabolic activity characteristics of single doses of insulin glargine given as U200 and U500 with those of a single dose of Lantus® U100 in a euglycemic clamp setting in subjects with type 1 diabetes.

To assess the safety and tolerability of single doses of U200, U500 and Lantus® U100 in subjects with type 1 diabetes.

Total study duration for each subject is between 3.5 and 12 weeks.

Two overnight stays at the unit in each of 3 treatment periods.

Inclusion criteria:

• Male or female subjects, between 18 and 65 years of age, inclusive, with type 1 diabetes mellitus for more than one year, as defined by the American Diabetes Association.
• Total insulin dose <1.2 U/kg/day.
• Minimum usual basal insulin dose ≥0.2 U/kg/day.
• Body weight between 50.0 kg and 110.0 kg, Body Mass Index between 18.5 and 30.0 kg/m2 inclusive.
• Fasting negative serum C-peptide (<0.3 nmol/L).
• Glycohemoglobin (HbA1c) ≤75 mmol/mol (≤9.0%).
• Stable insulin regimen for at least 2 months prior to inclusion in study.
• Certified as otherwise healthy for Type 1 diabetes mellitus patient.
• Women of childbearing potential with negative pregnancy test and use of a highly effective contraceptive method or women with confirmed postmenopausal status.
• Having given written informed consent prior to undertaking any study-related procedure.

Exclusion criteria:

• More than one episode of severe hypoglycemia with seizure, coma or requiring assistance of another person during the past 6 months.
• Frequent severe headaches and / or migraine, recurrent nausea and / or vomiting (more than twice a month).
• Presence or history of a drug allergy or clinically significant allergic disease according to the Investigator's judgment.
• Presence or history of drug or alcohol abuse (alcohol consumption >40 grams / day).
• Smoking more than 5 cigarettes or equivalent per day, unable to refrain from smoking.
• Any medication (including St John's Wort) within 14 days before inclusion, or within 5 times the elimination half-life or pharmacodynamic half-life of that drug, whichever the longest and regular use of any medication in the last month before study start with the exception of insulin products, thyroid hormones, lipid-lowering and antihypertensive drugs, and, if female, with the exception of hormonal contraception or menopausal hormone replacement therapy; any vaccination within the last 28 days; any biologics (antibody or its derivatives) given within 4 months before randomization.
• Known hypersensitivity to insulin glargine or excipients of the study drug.
• Any history or presence of deep leg vein thrombosis or a frequent appearance of deep leg vein thrombosis in first degree relatives (parents, siblings or children).

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.