Objective: The present study assessed safety and efficacy of Glaritus^® among adults with Type 1 Diabetes Mellitus (T1DM). Methodology: This prospective, randomized, multicenter, comparative, non-inferiority, open-label, parallel group, phase IV study was conducted in 14 study centers in India. Subjects were randomly allocated to receive either Glaritus^® or Lantus^® for 12 weeks. Each week, the dose of insulin was titrated to maintain target fasting blood glucose (FBG) level range of 80 - 120 mg/dL. Results: A total of 171 subjects were randomized (Glaritus^® arm-86; Lantus^® arm-85) and 161 subjects completed the study. The mean change in the glycosylated haemoglobin (HbA1c) levels from visit 3 (baseline) to visit 6 (end of trial) in Glaritus^® arm was -0.69 ± 1.81 and in Lantus^® arm was -0.53 ± 1.94. The mean change in glucose levels between week 1 and end of week 11 in Glaritus^® arm was -8.81 ± 34.57 and in Lantus^® arm was -5.28 ± 30. At least one hypoglycemic episode was experienced by 27.2% subjects of Glaritus^® arm and 28.6% subjects of Lantus^® arm. A total of 24 adverse events (AEs) such as pain, pyrexia, few infection related including urinary tract infections, metabolic related such as decreased appetite, musculoskeletal, neurological and skin related were reported in the study (Lantus^® arm: 14 AEs; Glaritus^® arm: 10 AEs). Conclusion: In this short term, 12-week study, biosimilar insulin glargine, Glaritus^®, is comparable to the reference product, Lantus^®, when combined with Insulin Lispro^® in terms of glycemic control, risk of hypoglycemia and occurrence of adverse drug reactions among adults with T1DM.