Primary Objective:

• to assess the relative bioavailability of a single dose of insulin glargine (Lantus) and lixisenatide given subcutaneously as on-site mix versus separate and simultaneous injections of each drug

Secondary Objectives:

• to compare the activity of a single dose of insulin glargine and lixisenatide given subcutaneously as on-site mix versus separate and simultaneous injections of each drug
• to assess the safety and tolerability of insulin glargine and lixisenatide given subcutaneously as on-site mix

The study period for one patient is one month in average and it can last up to 7 months (+ 2 weeks) with post-study and follow-up visits

Inclusion criteria:

• Subjects with type 1 diabetes mellitus for more than one year with total insulin dose of <1.2 U.kg/day, but otherwise healthy with glycohemoglobin (HbA1c) ≤ 9.0%, stable insulin regimen for at least 2 months prior to study, normal finding in medical history and physical examination.

Exclusion criteria:

• any history or presence of clinically relevant cardiovascular, pulmonary, gastro-intestinal, hepatic, renal, metabolic (apart from diabetes mellitus type I), hematological, neurological, psychiatric, systemic (affecting the body as a whole), ocular, gynecologic (if female), or infectious disease; any acute infectious disease or signs of acute illness
• 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)
• Symptomatic hypotension, or asymptomatic postural hypotension defined by a decrease in systolic blood pressure (SBP) equal to or greater than 20 mmHg within three minutes when changing from the supine to the standing position
• Presence or history of a drug allergy to clinically significant allergic disease
• Likelihood of requiring treatment during the study period with drugs not permitted by the clinical study protocol
• Pregnant or breast feeding women
• Any medication within 14 days before inclusion, or within 5 times the elimination half-life of that drug, whichever the longest and regular use of any medication other than insulins in the last month before study start with the exception of 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.
• Positive reaction to any of the following tests: hepatitis B surface (HBs Ag) antigen, antihepatitis B core antibodies (anti-HBc Ab) if compound having possible immune activities, anti-hepatitis C virus (anti-HCV2) antibodies, anti-human immunodeficiency virus 1 and 2 antibodies (anti-HIV1 and anti HIV2 Ab)
• History of unexplained pancreatitis, chronic pancreatitis and/or pancreatectomy

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