A Study Comparing the Efficacy and Safety of the Morning Injection of Toujeo Versus Lantus in Patients With Type 1 Diabetes Mellitus

Primary Objective:

To demonstrate that morning injection of Toujeo (HOE901-U300) compared to Lantus provides better glycemic control evaluated by Continuous Glucose Monitoring (CGM) in adult participants with type 1 diabetes mellitus.

Secondary Objective:

To demonstrate that treatment with HOE901-U300 compared to Lantus provides:

* Lower incidence rate of nocturnal symptomatic hypoglycemia;
* Better glucose control coverage during the last hours of CGM before next basal-insulin dosing;
* Less variability in CGM profile.

The maximum study duration per participant was to be of approximately 20 weeks that consisted of an up to a 4-week screening and CGM training period including a 1-2 week baseline (blinded) CGM performance (allowed for re-training), a 14-week open-label, comparative treatment period allowing for dose titration in both basal and meal-time insulin and including a 1-2 week end-of treatment blinded CGM collection with fixed dose of HOE901-U300 and Lantus, and a 2 day post treatment follow-up period.

Eligibility Criteria:
Inclusion criteria:

* Adult participants (male and female) with type 1 diabetes mellitus (T1DM).
* Signed written informed consent.

Exclusion criteria:

* Age \<18 years or \>70 years.
* Fasting c-peptide ≥0.3 nmol/L as per source document or central lab test at Visit 1.
* Glycated hemoglobin (HbA1c) ≤ 6.5 % or ≥ 10.0% via central lab test at Visit 1.
* Participants who experienced none of episode of documented symptomatic and/or severe hypoglycemia (as per the American Diabetes Association (ADA) classification) during the past month prior to screening.
* Participants who experienced \>1 episode of severe hypoglycemia resulting in coma/seizures during the last 12 months before screening.
* Participants received less than 1 year treatment with basal plus mealtime insulin.
* Used any basal insulins other than long-acting insulin analogs (ie, Lantus, Toujeo, Levemir, and Tresiba) in the past 3 months before screening.
* Required \>80 U/day basal insulin analogs or not on stable dose (±20% total dose) within 30 days prior to screening.
* Used fewer than 2 injections of rapid-acting insulin analog per day within 30 days prior to screening.
* Used human regular insulin as mealtime insulin within 30 days prior to screening.
* Used an insulin pump during the last 6 months before screening.
* History of unstable proliferative diabetic retinopathy or any other rapidly progressive diabetic retinopathy or macular edema likely to required treatment (e.g., laser, surgical treatment, or injectable drugs) during the study period.
* Pregnant or breast-feeding women or planned pregnancy during the duration of the study.
* Use of any other investigational drug(s) within 1 month or 5 half-lives, whichever was longer prior to screening.
* Inappropriate CGM use during screening period evidenced by failure to obtain a minimum of 4 days of usable records by the end of screening.
* Noncompliance with self-monitored plasma glucose (SMPG) performance evidenced by failure to demonstrate at least 5 days of 5 point SMPG records by the end of screening.

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