OBJECTIVE SENIOR compared the efficacy and safety of insulin glargine 300 units/mL (Gla-300) with glargine 100 units/mL (Gla-100) in older people (≥65 years old) with type 2 diabetes.

RESEARCH DESIGN AND METHODS SENIOR was an open-label, two-arm, parallel-group, multicenter phase 3b trial designed to enroll ∼20% of participants aged ≥75 years. Participants were randomized 1:1 to Gla-300 or Gla-100, titrated to a fasting self-monitored plasma glucose of 5.0–7.2 mmol/L (90–130 mg/dL).

RESULTS In total, 1,014 participants were randomized (mean age: 71 years). Comparable reductions in HbA_1c were observed from baseline to week 26 for Gla-300 (−0.89%) and Gla-100 (−0.91%) in the overall population (least squares mean difference: 0.02% [95% CI −0.092 to 0.129]) and for participants aged ≥75 years (−0.11% [−0.330 to 0.106]). Incidence and rates of confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycemia events were low and similar between both treatment groups, with lower rates of documented symptomatic hypoglycemia with Gla-300. The lower risk of hypoglycemia with Gla-300 versus Gla-100 was more apparent in the subgroup aged ≥75 years versus the overall population. Significantly lower annualized rates of documented symptomatic (≤3.9 mmol/L [≤70 mg/dL]) hypoglycemia were observed (Gla-300: 1.12; Gla-100: 2.71; rate ratio: 0.45 [95% CI 0.25–0.83]).

CONCLUSIONS Efficacy and safety of Gla-300 was demonstrated in older people (≥65 years of age) with type 2 diabetes, with comparable reductions in HbA_1c and similarly low or lower risk of documented symptomatic hypoglycemia versus Gla-100. A significant benefit in hypoglycemia reduction was seen in participants aged ≥75 years.