Impact of Switching from Twice-Daily Basal Insulin to Once-Daily Insulin Glargine 300 U/mL in People with Type 1 Diabetes on Basal-Bolus Insulin: Phase 4 OPTIMIZE Study.

Introduction: OPTIMIZE evaluated the efficacy, safety and treatment satisfaction of insulin glargine 300 U/mL once daily (Gla-300 OD) in people with type 1 diabetes mellitus (T1DM) previously uncontrolled on basal insulin twice daily (BID) as part of basal-bolus therapy.

Methods: OPTIMIZE was a 28-week, prospective, interventional, single-arm phase 4 trial in adults with T1DM. At baseline, basal insulin BID treatment was switched to Gla-300 OD titrated to a fasting self-monitored blood glucose target of 4.4-7.2 mmol/L (80-130 mg/dL). The primary endpoint was the mean glycated haemoglobin (HbA) change from baseline to week 24. Secondary endpoints included self-monitored blood glucose, fasting-plasma glucose, hypoglycaemia and patient-reported outcomes including the Diabetes Treatment Satisfaction Questionnaire status version (DTSQs).

Results: Switching to Gla-300 OD significantly improved mean HbA (8.54% at baseline and 8.27% at week 24 [last observation carried forward, N = 94, p < 0.0001]; mean difference 0.27% [95% CI 0.15, 0.40]). There was a statistically significant decrease in fasting self-monitored blood glucose during the study (analysis of variance for repeated measures, p = 0.014; N = 72). Eight-point self-monitored blood glucose was significantly improved between baseline and week 24 for post-breakfast (p = 0.009), post-dinner (p = 0.009) and bedtime (p = 0.049) values. The study did not allow for any significant effects on confirmed and/or severe hypoglycaemia at the ≤ 3.9 mmol/L [≤ 70 mg/dL] or < 3.0 mmol/L [< 54 mg/dL] blood glucose cut-offs to be observed. Statistically significant improvements were observed in DTSQs total scores from baseline (24.1) to week 24 (29.4, p < 0.0001).

Conclusions: A basal-bolus regimen including Gla-300 OD was associated with improvements in HbA and treatment satisfaction in people with uncontrolled T1DM previously receiving basal-bolus insulin including a basal insulin BID analogue.

Trial Registration: EudraCT number: 2015-001186-46.