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.